Dyslipidemia and Xanthine Oxidoreductase level in Jordanian
Patients with Rheumatoid Arthritis
Najah Al- Muhtaseb
1*
, Elham Al-Kaissi
2*
, Zuhair Muhi eldeen
1b
, Naheyah Al-
Muhtaseb3
1
Department of Pharmaceutics and biotechnology, Faculty of Pharmacy, Petra
University, Amman, Jordan.
2
Department of Medicinal chemistry and Pharmacognosy, Faculty of Pharmacy, Petra
University, Amman, Jordan
3
Rehabitation Medicie (RMS).
P.O. Box 961343 Amman, Jordan, Fax 00962-6-5715551, Tel. 00962-6-05715546
1
Associated Prof
2
Associated Prof.
1b
3
Full Prof
MD
* Contributed equally
E mails:
1
2
naj_nim@yahoo.com
Kaielham@hotmail.com
1b
eldeenz@hotmail.com
3
1
naheyah@hotmail.com
Abstract
Context: Rheumatoid arthritis (RA) is associated with an excess mortality from
cardiovascular disease which might be due to an increased prevalence of
cardiovascular risk factors such as dyslipidemia, and free radical generating enzyme
such as xanthine oxidoreductase (XOR). Thus, they appear to be suitable markers for
clinical studies of lipid profile and XOR level in patient with RA and related
cardiovascular risk.
Objectives: of the study were to assess the prevalence of blood dislipidemia and the
levels of blood and synovial XOR in Jordanian patients with untreated active
rheumatoid joint diseases and to investigate the clinical and biological associated
factors.
Methods: Synovial fluids and blood were collected from one hundred twenty seven
patients with active RA (63 male and 64 female). One hundred eleven age matched
individuals were included as control. Blood lipid profile, apolipoproteins (Apo), blood
and synovial XOR proteins level were determined.
Results: the levels of patient serum cholesterol (C), low density lipoprotein (LDL)Cholesterol, Apo B, triglyceride (TG), very low density lipoprotein (VLDL-TG),
LDL-TG, Apo C-III, Apo C-III/TG, Apo B/Apo A-I, and LDL-C/high density
lipoprotein (HDL)HDL2-C ratios were significantly increased in RA patients. A
significant reduction in the levels of HDL-, HDL2-, HDL3-C, serum Apo A-I, ApoAII, HDL-Apo A-I, and HDL2-C/HDL3-C ratio were found in RA patients compared to
healthy controls. Increased XOR in serum and synovial fluid were observed in the RA
patients studied.
.
Conclusions: Abnormalities in lipids, lipoproteins, apolipoproteins and XOR were
found in RA patients. Our data favor an enhanced affinity towards atherosclerosis in
2
these patients. Management of dyslipidemia should consider as a part of
cardiovascular risk management in RA patients. Attention must be paid to lipids
profile for those RA patients with previous history of a cardiovascular event.
Keywords: Dyslipidemia, lipid profile, atherogenesis, Synovial fluid, Apolipoprotein
(Apo).
1. Introduction
Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown etiology
affecting primarily the synovium, leading to synovial inflammation, joint and bone
damages, it affects 1-2% of the population, with mortality ratios ranging from 1.3 to
3.0 (Kimac et al. 2010; Helmick et al. 2008; Nurmohamed 2007; Goodson and
Solomon 2006; Georgiadis et al. 2006; Watson et al. 2003; Van Doornum et al. 2002;
Lems and Dijkmans 2000). Patients suffering from rheumatoid arthritis (RA) are at
greater risk of developing cardiovascular disease with 70% increase in risk of death
(Lourida et al. 2007; Soubrier and Dougados 2006; Sattar et al. 2003). Clinical and
subclinical vacuities accelerated atherosclerosis and increases cardiovascular
morbidity and mortality among RA patients (Georgiadis et al. 2006; Gabriel et al.
2003; Van Doornum et al. 2002; Goodson 2002; Bacon and Kitas 1994; Reilly et al.
1990). This increased cardiovascular risk may resulted from several factors such as
dyslipidemia, accelerated atherosclerosis, diabetes mellitus, high blood pressure,
higher body mass index (BMI), sex and age (Goodson and Solomon 2006; Dessein et
al. 2005; Pincus and Callahan 1986) and finally, the chronic inflammatory
components, and the effects of drugs used in RA treatment on the lipid profile (Ku et
al. 2009; Chung et al. 2008; Shoenfeld et al. 2005). In recent years, free radicals
reactions and other reactive intermediates produced in normal metabolic processes
have been implicated in the pathogenic mechanism of a wide range of diseases,
3
including acute coronary syndrome (Cheng-xing et al. 2004 ), in others cardiovascular
diseases (Dawson and Walters 2006) and inflammatory diseases (Chung et al. 1997).
XOR has generated excited widespread research result in its ability to reduce
molecular oxygen, generating free radical superoxide anion (O2-) and hydrogen
peroxide (H2O2) mediating ischemia-reperfusion damage in heart and joint
(Almuhtaseb 2012). Studies concerning the levels of total cholesterol (TC), total
triglyceride (TG), very low density lipoprotein- triglyceride (VLD-TG), low density
lipoprotein-cholesterol (LDL-C) and low levels of high density lipoprotein-cholesterol
(HDL-C) particularly HDL2-C and inconclusive in RA patients yielded contradictory
data (Arts et al. 2012; Garcia-Gomez et al. 2009; Nurmohamed 2007; Assous et al.
2007; Van halm et al. 2007; Solomon et al. 2004; Park et al. 2002; Park et al. 1999;
Austin et al. 1998). Increased levels of total TC, LDL-C and low levels of HDL-C,
and HDL2-C are associated with an increased incidence of cardiovascular disease in
general population (Choy and Sattar 2009; Castelli et al. 1986). The inflammatory
environment and disturbed antioxidant mechanisms due to increased XOR in RA may
promote LDL oxidation, thereby facilitating atherogenesis at low ambient lipid
concentration and placing RA patients at higher cardiovascular risk (Nurmohamed
2007; Situnayake et al. 1991). Little attention has been given to apolipoproteins, the
carriers of structural and functional properties of serum lipoproteins (Knowlton et al.
2012), including Apo A-1, Apo B which differ not only in their apolipoprotein
composition but also in their metabolic properties and non-atherogenic and
atherogenic capacities (Alaupovic 2003; Blankenhom et al. 1990). Serum
apolipoproteins measurement is considered to be better discriminators than the total
levels of lipoprotein (Walldius and Jungner 2006). Apo C-II and Apo C-III have also
been reported to play an important role in the catabolism of TG and hence may
4
contribute to cardiovascular disease (Havel et al. 1973). Apo C-II is activator of
lipoprotein lipase (LPL) which hydrolysates TG while Apo C-III inhibits the enzyme
(LaRosa et al. 1970). Apo C- III was shown to interfere with binding of Apo B
containing lipoprotein to hepatic lipoprotein receptors (Brown and Banginsky 1972)
and has link with the inflammatory processes (Clavey et al. 1995; Wang et al. 1985).
Recently, new data on dyslipidemia in RA patients have been published which
changed our insights about the lipid profile in RA patients (Knowlton et al. 2012;
Hemick et al. 2008; Solomon et al. 2003; Wolfe et al. 2003; Koopman 2001). The aim
of this study is to assess the prevalence of dyslipidemia and the level of synovial and
blood XOR in Jordanian patients with active RA and to investigate the clinical and
biological associated factors.
.
2. Materials and Methods
2.1. Subjects and clinical evaluation
127 RA patients, diagnosed according to the ACR criteria for classification of the
disease (Arnett et al 1988), and 111 control subjects, matched for age, sex, smoking
status and blood pressure were enrolled after giving informed consent. The patients
had active disease, as evaluated by a Disease Activity Score (DAS 28=6.5 ± 0.2)
according to EULAR’s recommendations (Fransen and Riel 2005) and 63 were
Rheumatoid factor positive. No subject had any symptom or laboratory finding of
kidney, liver or thyroid dysfunction, infection, diabetes, malignancy, or was taking
drugs affecting plasma lipid or lipoprotein levels. None had been treated with
corticosteroids or disease modifying anti-rheumatic drugs prior the study. All subjects
had sedentary habits and were not participating in any regular physical exercises. The
present investigation was approved by the hospital ethics committee and was in
accordance with the principles outlined in the declaration of Helsinki.
5
After overnight fast (15 h) venous blood samples of all participants (patients and
controls) were collected in plain tubes (1.5 mg/ml, Monojet, Division of Sherwood
Medical). The samples after their complete coagulation were centrifuged at 4oC (500
g; 15 minutes) to separate clear sera. The sera were divided into two portions, one for
detection the levels of IgG and IgM and the other for immediate analysis of
rheumatoid factor (RF), C-reactive protein (CRP), Uric acid (Balis 1976), glucose
(Trinder 1969), phospholipid (Takayama et al. 1977), and XOR activity (Nishino
1994; Avis et al. 1956). The ultracentrifugal fractionation for VLDL, LDL, Total
HDL, HDL2, and HDL3 fractions (for C and TG), serum triglycerides, and total
cholesterol, were determined in triplicate with standard enzymatic techniques by using
an Abbott VP supersystem autoanalyser (Abbott Diagnostic Division, maidenhead,
UK). Erythrocytes sedimentation rate (ESR) was determined for the first hour.
2. 2. Separation of lipoprotein
Separation of lipoproteins was performed by a modified sequential ultracentrifugation
method (Havel et al. 1955) in a preparative ultracentrifuge (Sorvall OTD 75B,
Bomedical products) in a fixed angle rotor (type TFT 48.6) with appropriate adaptors.
The procedure was outlined in (Al-Muhtaseb et al. 1989).
Apolipoproteins A-I, A-II and B, C-П and C-Ш values were determined by
immune-turbidimetric method using Daiichi kit (Auto N Daiichi, Daiichi pure
chemicals Co. Ltd, Tokyo, Japan) and preceded according to the manufacturer
recommendation.
For Apo AI inter assay and intra assay coefficient of variation was less than 3.5%
at a level of 150 mg/dl and less than 4% at a level of 100mg/dl. For Apo A-II the
coefficient of variation was less than 4.5% at a level of 70mg/dl and less than 4.5% at
a level of 40 mg/dl. For Apo B it was less than 4.5% at a level of 70mg/dl. Apoprotein
6
C-II and C-III values, the Inter assay and intra assay coefficient of variation was
within the recommended range (below 10%).
2. 3. LCAT activity assay
The method was according to that reported by Dieplinger and Kostner in 1980.
2. 4. Rheumatoid factor detection (RF)
Rheumatoid factor is detected by latex agglutination test using appropriate plates from
Behring (Germany) according to the manufacturer recommendations. Fifty µL of
latex coated with human IgG was added to different dilutions from each serum
sample. Negative and positive sera were used as controls. After two minutes a clear
agglutination is observed in the positive indicating the presence of RF. Sera with titer
less than 20 IU/ml were considered negative according to the manufacturer
recommendation.
2. 5. C - reactive protein (CRP) concentration determination
CRP concentration was determined by latex agglutination test using appropriate plates from
Behringer (Germany) and preceded as recommended by the manufacturer. 2.4 µl of patient
serum is added to 120 µl buffer solutions (pH 8.5) and mixed with 120 µl suspension of mouse
anti-human CRP monoclonal antibody that is bound to latex (2mg/ml) and incubated for 5
minutes. CRP binds to the latex-bound antibody and agglutinates. The resulting agglutination
was measured spectrophotometrically at 580 nm, negative and positive control samples were
included. Values higher than 9.4 mg/l for females and 8.55 mg/l for males were consider as
positive.
2. 6. The erythrocyte sedimentation rate (ESR)
Was determined using modified Westergren method (Belin et al. 1981).
2. 7. Purification of Xanthine oxidoreductase
7
The purification and total protein estimation for XOR enzyme and xanthine oxidase
activity assay were determined according to the previous method (Al-Muhtaseb et al.
2012).
2. 8. Protein estimation
Protein was estimated by the method of lowry et al. 1951, using Folin phenol reagent,
bovine serum albumin was used as the standard.
2. 9. Xanthine oxidase activity in the synovial fluid assay
Total xanthine oxidase activity of the synovial fluid was determined by measuring the
rate of oxidation of xanthine to uric acid spectrophotometrically at 295 nm in a Cary
100 spectrophotometer, using a molar absorption coefficient (ε ) of 9.6 mM-1 (Avis et
al. 1956.
2. 10. Assays
Were performed at 25.0 ± 0.2o C in air-saturated 50 mM Na / Bicine buffer, pH 8.3,
containing 100μM xanthine. Total (oxidase plus dehydrogenase) activity was
determined as above but in the presence of 500 μm NAD+. Dehydrogenase content of
an enzyme sample was determined from the ratio of oxidase and total activities
2. 11. Assay of xanthine oxidase activity in the blood (Nishino 1994):
2. 11. 1. Principle of the xanthine oxidase method:
Xanthine oxidase
Xanthine + O2 + H2O
Uric acid + H2O2
The rate of formation of uric acid is determined by measuring increased absorbance at
290 nm. A unit of activity is that forming one micromole of uric acid / minute. The
procedure was done according to the procedure recommended by abdelhamid et al.
2011.
8
2. 12. Single radial immunodiffusion assay (SRID)
To determine the levels of total IgG and IgM as in (Al-Muhtaseb 2012)
2. 13. Statistical analysis
Statistical analysis was carried out using Student's t test by statistical packages for
social science software (SPSS). Values are expressed as mean ± SD and values of p
<0.05 were considered statistically significant. The relationships between variables
were calculated using Pearson Correlation Coefficients.
3. Results
Patients positive for rheumatoid factor labeled as rheumatoid arthritis + (RA+), while
seronegative patients were labeled as other joint inflammation (RA-). Latex
agglutination used in determining IgM-RF factor showed that, of the 127 patients 63
(32 male, 31 female) were RA+ (Seropositive) and 64 (31 male, 33 female) were RA(Seronegative), the Clinical and biochemical characters of the participated subjects are
shown in table 1.
The mean age and BMI for both rheumatoid arthritis RA+ and other joint
inflammation RA- and their control subjects were comparable. ESR ( after one hour)
and CRP values were significantly elevated in patients with rheumatoid arthritis
(RA+) compared with values in patients with other joint inflammation (RA-) and to
those of the control values.
Latex agglutination used in determining IgM-RF showed that of the 127 patients
32 males and 31 females were RA+ (seropositive) and 31 males and 33 females were
RA-( seronegative).
Concentrations of fasting plasma glucose were normal in both male and female
rheumatoid arthritis (RA+, RA-) patients compared to control subjects. On the other
9
hand, uric acid levels were significantly elevated in male and female rheumatoid
arthritis RA+ and RA- patients compared with their controls (P < 0.001).
Both RA+ and RA- (male and female) rheumatoid arthritis patients had
significantly increased TC, VLDL-C, LDL-C, TTG, VLDL-TG, HDL-TG, and
phospholipids concentrations when compared with the corresponding control subjects
(Table
2).
Whereas,
LDL-C,
TG,VLDL-TG,
LDL-TG,
and
phospholipids
concentrations were lower in RA- female patients compared to RA+ rheumatoid
arthritis female patients.
Marked reduction in HDL-, HDL2- and HDL3-C was
observed in RA+ and RA- male and female patients compared to controls. There was
no significant difference in the variables studies in RA+ compared to RA- rheumatoid
arthritis male patients (Table 2). On the other hand, male RA+ and RA- rheumatoid
arthritis patients, TC, VLDL-C, LDL-C, TG, VLDL-TG, and total phospholipids
concentrations were higher than in female RA+ and RA- rheumatoid arthritis patients.
In male controls, T-C, VLDL-C, LDL-C, TTG, VLDL-TG, and phospholipids
concentration
were
higher
than
in
control
females.
There was no significant difference in HDL-C, HDL2- HDL3-C and HDL-TG in male
and female RA+, RA- patients.
Serum apolipoprotein A-I, A-П, B, C-П, and C-IП concentrations of rheumatoid
arthritis patients and controls are shown in Table 3. Significantly reduced serum levels
of Apo A-I, Apo A-II and Apo A-I in HDL fraction were observed in both male and
female RA+ and RA- rheumatic arthritis patients compared with control subjects.
Apolipoprotein B in serum and in LDL fraction with serum Apo C-IП concentrations
were significantly elevated in both male and female rheumatoid arthritis (RA+ and
RA-) patients compared with their control groups (Table 3). There was no significant
10
difference in Apo C-П in either rheumatoid arthritis group compared with their
control group.
Serum Apo A-I, Apo A-II, HDL-Apo A-I, serum Apo B, LDL-Apo B, and serum
Apo C-П, levels did not differ between RA+ and RA- rheumatoid arthritis male
patients, where as serum Apo A-I, Apo A-II, HDL-Apo A-I, and LDL-Apo B levels
did not differ in RA+ and RA- rheumatoid arthritis female patients, but in case of
serum Apo B and serum Apo C-ПI were significantly decreased in both RA+ and RAfemale rheumatoid arthritis patients and the decrease in RA- were more significant.
In female control subjects, serum Apo A-I, Apo A-II, HDL-Apo A-I, serum Apo B
and LDL- Apo B were signicantly lower than in control male subjects.
Serum lecithin cholesterol acyltransferase (LCAT), serum and synovial xanthine
oxidase (XO) activities of patients with rheumatoid arthritis and controls are shown in
table 4.
Serum LCAT was decreased significantly in all rheumatoid arthritis female and
male groups compared with healthy controls, while serum xanthine oxidase
concentrations were elevated significantly in male and female (RA+ and RA-)
rheumatoid arthritis patients groups when compared with control groups.
Serum XO and synovial XO activity were significantly decreased in both male and
female RA- rheumatoid arthritis patients compared to RA+ rheumatoid arthritis
patients.
Total IgG and IgM (mg/dL) titers in sera of patients with rheumatoid arthritis
(RA+), other joint inflammation (RA-), and healthy volunteers, using SRIDA are
shown in (Table 5). Both blood IgM and IgG levels were significantly higher in male
and female (RA+ and RA-) rheumatoid arthritis patient groups than in control groups.
Similarly, the levels were higher in serum of patients with other joint inflammation
11
(RA-) than in RA+ patients (P< 0.01). IgG levels were more elevated in serum of
patients with rheumatoid arthritis (RA+) compared to other joint inflammation (RA-)
in both male and female (P< 0.001).
Total IgM and IgG (mg/dL) levels in serum were significantly higher in male and
female rheumatoid arthritis (RA+) in comparison to the levels in patients with other
joint inflammation (RA-) both male and female (P< 0.01).
Ratio of lipid fractions and apolipoproteins in control groups, male and female
patients with rheumatoid arthritis (RA+ and RA-) are shown in (Table 6)
Significantly increased T-C /HDL-C, LDL-C/HDL-C, LDL-C/HDL2-C, Apo B/Apo
A-1 and Apo C-III/TG ratios, and reduction in HDL2-C/HDL3-C were observed in the
male and female rheumatoid arthritis pateints compared with controls. Where as
HDL-C/Apo A-1 and TC/Apo B ratios did not differ when compared with controls
(Table 6). On the other hand TC/HDL-C were significantly increased in (RA+)
rheumatoid arthritis compared to RA- male and female patients. The remaning ratios
did not differ between male and female RA+ with RA- rheumatoid arthritis patients.
3. 1. The correlations between variables:
For the groups combined HDL-C correlated positively with Apo A-I (r=0.50, P<
0.001), and negatively with TG ( r=-0.60, P< 0.001) and Apo B (r=-0.47, P< 0.001),
Triglycerides correlated positively with Apo B (r=0.61, P< 0.001), and with Apo C-III
( r=0.51, P< 0.001). Apo C-III correlated negatively with HDL-C (r= -0.53, P<
0.001) and HDL2-C (r=-0.56 P P< 0.001).
Serum TG and VLDL-TG were correlated positively with serum Apo-B and LDLApo B (r=0.62, r=0.5.2, P< 0.001 for both) and Apo-CIII(r=0.43, P< 0.001) and
negatively with serum HDL-C, HDL2-C ( r= -0.46, r=-0.50, P< 0.001 for both), serum
Apo A-I, HDL-Apo A-I (r=-0.44, r=-0.51, P< 0.001 for both). In the RA+ and RA-
12
both sex group patients. In contrast, serum C and LDL-C correlated positively with
TG, serum Apo B, LDL-Apo B (r=0.49, r=0.69, P< 0.001 for both) and negatively
with HDL-C, HDL2-C (r= -0.53, r= -0.60, P< 0.001 for both), serum Apo A-I and
HDL-Apo A-I ( r=-0.51, r= -0.58, P< 0.001 for both).
4. Discussion
The elevated levels of CRP, ESR, beside IgM rheumatoid factors in both male and
female patient groups reported in this study indicate inflammation. The slightly higher
levels of total IgG and IgM titres in RA+ patients compared to the levels in RApatients and to the levels in healthy control are inconsistent with other investigators
(Arrar et al. 2008; Ng and Lewis 1994; Harrison et al. 1990), which is due to the
autoimmune difference in the nature of the disease among individuals. On the other
hand the synovial fluids of patients with RA+ and RA-showed lower levels of total
IgG and IgM compared to the levels in their sera, these data were not in agreement
with the finding of others (Arrar et al. 2008; Ng and Lewis 1994; Harrison et al.
1990). The low synovial levels may be attributed to bound immunoglobulins to the
tissue or bound in immune complexes which need to be detected by other more
sensitive techniques than SRID. In fact the pathology of RA is attributed to an Arthus
like reaction in which immune complexes mediate the crucial role.
Recent research has shown that systemic inflammation plays a pivotal role in
development of atherosclerosis (Nurmohamed 2007; Soubrier and Dougados 2006;
Rohrer et al. 2004; Saito et al. 2003; Biondi-Zoccai et al. 2003; Lind 2003). Hence,
inflammation might explain the increased cardiovascular risk in RA patients (Sattar et
al. 2003). In our study, RA+ patients showed dyslipidaemia and mark atherogenic
lipid profile compared with the healthy controls. This atherogenic lipid profile
includes elevated TC, VLDL-C, LDL-C, TTG, VLDL-TG, LDL-TG and phospholipid
13
levels observed in male RA+ and RA- patients, and in female RA+ patients only is in
agreement with some of the previously reported data (Zrour et al. 2011; Yoo 2004;
Park et al. 1999), and disagrees with others (Myasoedova et al. 2010; Oliviero 2009).
The observations of significant differences found in female RA+ and RA- patients
may suggests that the inflammation was more sever in RA+ women or due to a
decrease in endogenous estrogen (Magkos et al. 2010; Atsma et al. 2006; Krauss et al.
1979).
Elevated total VLDL-C and LDL-C observed in this study have been previously
reported (Walldius and Jungner 2004), this elevation may be due to changes in the
inter composition of LDL particles as a consequence of increased flux of VLDL, or
due to diet or physical exercise (Metsios et al. 2010). Alternatively, a decreased rate
of LDL catabolism arising from increase LDL receptor uptake could explain this
observation (Walldius and Jungner 2004).
.
Our RA patients had high levels of total, VLDL and LDL-TG than the control
group, which agrees with others (Tian et al. 2011; Aberg et al. 1985). The high level
of TG may caused by increased production of VLDL-TG or decrease in TG catabolic
rate as a result of impairment of LPL activity associated with inflammation (Tian et
al. 2011). Alternatively, elevated VLDL-TG in these patients could be due to influx of
free fatty acids into the liver as excess substrate for hepatic TG synthesis. And
because VLDL-C, LDL-TG levels were elevated, such abnormalities may reflect an
elevated concentration of remnant lipoprotein metabolism.
Low levels of total HDL-C, HDL2-C, HDL3-C, and a high LDL-C, found in our
study, is strongly associated with an increased risk of atherosclerosis, which is
inconsistent with previous study (Arts et al. 2012; Regnstron et al. 1992), furthermore,
the reduction in HDL-C occurs predominantly in the HDL2 subfraction which is
14
conforms with previous reports (Arts et al. 2012; Regnstron et al. 1992). The inverse
correlation seen between HDL-C and HDL2-C with VLDL-TG could lead to
decreased production of HDL particularly HDL2 from TG-rich lipoproteins (Tian et
al. 2011; Nikkila et al. 1987).
Apolipoprotein A-1 is the predominant apolipoprotein in HDL, and apolipoprotein
B is the predominant apolipoprotein in LDL (Walldius and Jungner 2004; Jones et al.
2000; Gibbons 1986). The observed high levels of apolipoprotein B and its correlation
with other blood lipids reported in male RA+, RA- and female RA+ patients may be
associated with the increased
production and/ or impaired catabolism of LDL,
possibly apolipoprotein B due to inflammation (Van Doornum et al. 2002). In contrast
to Apo B, the reduction in serum Apo A-I and Apo A-II levels are in agreement with
other studies (Yamada et al. 1998). ApoA-1 is reported to inhibit the production of
pro-inflammatory cytokines including IL-1, TNF-α and interactions between T-cell
and monocytes (Zhang et al. 2010; Burger and Dayer 2002). This suggests that a less
favorable lipid profile stimulates a pro-inflammatory status which might be related to
RA disease activity or susceptibility. Our finding is in line with the researchers who
believed that serum Apo A-I concentrations should be declined during active phase of
RA, and has played an important role as anti-inflammation (Zrour 2011; Zhang et al.
2010; Barry et al. 2004; Burger and Dayer 2002). Chronic inflammation such as RA
was also associated with low HDL-C and altered HDL composition (Rohrer et al.
2004). Other researchers reported that Apo A-I and Apo B levels are decreased
(Chenaud et al. 2004; Jonas 2000). The reported Low HDL, HDL2-C and
apolipoprotein A-1 levels and their inverse correlation with TG, VLDL-TG,
phospholipids and apolipoprotein B levels in our study may be due to an increased
15
production of acute phase proteins by the inflamed liver at the expense of lipoprotein
production, thereby tending to reduce lipoprotein levels (London et al. 1963).
In the previous studies in autoimmune diseases as RA it were shown that Apo C-III
and TG levels are increased (Knowlton 2012; Nicolay et al. 2006; Walldius and
Jungner 2004), In our study we found increased levels in total-TG and VLDL-TG in
males, females RA+ and RA- patients with increase in Apo C-III but not Apo C-II
levels. Furthermore, our finding of high Apo B and lower Apo A-I, HDL-C and
HDL2-C with their correlations to Apo C-III, may provide additional information in
that Apo C-III level probably reflects an independent risk factor in RA patients
(Knowlton 2012). The fact that Apo C-III alone or as one of the protein components
of the Apo B-containing lipoprotein sub-classes is linked to inflammatory processes
and atherogenesis, underscores its great potential as a new marker and diagnostic test
for cardiovascular diseases in RA patients (Knowlton 2012). In a recent study it was
shown that only those LDL particles that contain Apo C-III are atherogenic and those
particles without Apo C-III are not (Mendivil et al. 2011).
The plasma LCAT, which is activated by Apo A-I, plays role in the metabolism of
lipoproteins as co-factor for esterification of free cholesterol (Tian et al. 2011;
Walldius and Jungner 2004). The finding of low LCAT activity, low Apo A-I and
high level phospholipids in both RA+, RA- male and female patients compared to
healthy control may suggest the influence of LCAT on HDL-C level.
The increased ratio of LDL-C/HDL-C, LDL-C/HDL2-C, TC/HDL2-C, Apo B/Apo A-I
and Apo C-III/TG as observed in RA+, RA- patients was considered a predisposing
factor to increased risk of cardiovascular diseases in RA patients. The higher the
value of the Apo B/Apo A-I ratio, the more circulating cholesterol in the plasma
compartment (Tian et al. 2011; Walldius and Jungner 2004), this cholesterol is likely
16
to be deposited in the arterial wall, provoking atherogenesis and risk of coronary
vascular events.
Assessing the Apo B/ Apo A-1 ratio and total TG levels was recommended to
predict high cardiovascular risk patients in the general population (Tian et al. 2011;
Walldius and Jungner 2006) in our study the ratio was higher in male, female RA+
and RA- patients in comparison to controls, these data in support of cardiovascular
risk.
Studies suggest that free radical mediated oxidative stress can influence the plasma
lipid concentrations and generate potent proatherogenic mediators (Kowsalya et al.
2011). These free radicals also play an important role in the development of
atherosclerosis vascular disease and other complications seen in RA (Mccord 2000;
Ross 1999). Our study showed increased activity of serum and synovial XOR in male,
female RA+ patients compared to RA- patients, may reflect the severity of the
inflammation in RA+ patients. Therefore XOR can not be used as marker for
detection of myocardial infarction as recommended by other (Abdelhamid et al.
2011). XOR is an important free radical generator (Hearse et al. 1986; Chambers et al.
1985), acts on hypoxanthine and xanthine with the resultant production of oxygen free
radicals (Abdelhamid et al. 2011; Raghuvanshi et al. 2007). Free radical generation
result in damage to vascular endothelium (Kundalic et al. 2003), Damage to
extracellular matrix, and that changes in matrix structure can play a key role in the
regulation of cellular adhesion, proliferation, migration, and cell signaling;
furthermore, the extracellular matrix is widely recognized as being a key site of
cytokine and growth factor binding, and modification of matrix structure might be
expected to alter such behavior (Rees et al. 2008).
17
.
As inflammation only explained a small part of the observed differences in lipids
between the persons who later develop RA and the controls we recommend that a less
favorable lipid profile might be related to the development of RA by a common or
linked background, as socio-economic, ethnic, racial and geographic differences. Both
genetic and dietary factors may contribute to high lipoprotein levels, especially
increases fat and cholesterol consumption (van Wietmarschen and van der Greef
2012; Cesur et al. 2007). Alternatively, lipids might modulate the susceptibility to
RA.
5. Conclusion
Our finding support the following finding
a- Lipid profile particularly the Apo B/ Apo A-1 ratio and TG levels, HDL2-C
assessments and CRP was recommended to predict high cardiovascular risk
patients in the general population.
b- Management of dyslipidemia should considered as a part of cardiovascular risk
management in RA patients.
c- Cardiovascular risk factor screening and appropriate treatment in form of
antioxidant supplementation or antihyperlipidemic agents may be necessary for
reducing the morbidity and mortality in these patients.
Further research to examine the relation between dyslipidemia, the effects of chronic
inflammation on lipids, atherosclerosis and cardiovascular mortality may be of
importance to both rheumatologists and cardiologists.
18
6. References
[1] Abdelhamid MA, Salim BI, and Abdelsalam KA (2011) Possibility of xanthine
and malondialdehyde as a marker for myocadial infarction. Sudan JMS 6(2): 9396.
[2] Aberg H, Lithell H, Selinus I and Hedstand H (1985) Serum triglycerides are a
risk factor for myocardial infarction but not for angina pectoris. Atherosclerosis
54(1): 89-97.
[3] Alaupovic P (2003) The concept of apolipoprotein-defined lipoprotein families
and its clinical significance. Curr Atheroscler Rep 5: 459-467.
.
[4] Al-Muhtaseb N, Al-Kaissi N, Thawaini AJ, Muhi-Eldeen Z, Al-Muhtaseb S,
Al-Saleh B (2012) The role of human xanthine oxidoreductase (HXOR), antiHXOR antibodies and microorganisms in synovial fluid of patients with joint
inflammation. Rheumatology International 32: 2355-2362.
[5] Al-Muhtaseb N, Al-Ysuf AR, Abdella N, Fenech F (1989) lipoproteins and
apolipoproteins in young nonobese Arab women with NIDDM treated with
insulin. Diabetes Care 12: 325-331.
.
[6] Austin MA, Hokanson JE, Edwards KL (1998) Hypertriglyceridemia as a
cardiovascular risk factor. Am J Cardiol 81: 7B-12B.
[7] Arnett FC, Edworthy SM, Bloch DA, Mcshane DJ, Fries JF, Cooper NS et al .
(1988) The American Rheumatism Association revised criteria for classification
of rheumatoid arthritis. Rheum 31: 315-324.
.
[8] Arrar L, Hanachi N, Rouba K, Charef N, Khennouf S, Baghiani A (2008)
Antixanthine oxidase antibodies in sera and synovial fluid of patients with
rheumatoid arthritis and other joint inflammations. Saudi Med J 29: 803-807.
[9] Arts E, Fransen J, Lemmers H, Stalenhoef A, Joosten L, van Riel P, and Popa CD
19
(2012) High-density lipoprotein cholesterol subfractions HDL2 and HDL3 are
reduced in women with rheumatoid arthritis and may augment the cardiovascular
risk of women with RA: a cross-sectional study. Arthritis Res Ther 14: R116.
[10] Assous N, Touze E, Meune C, Kahan A, Allanore Y (2007) Morbimortlite
cardiovasculaire au cours de la polyarthrite rhumatoide: etude de cohort
hospitaliere monocentrique fencaise. Rev Rhum 74: 72-78.
[11] Atsma F, bartelink ML, Grobbee DE, vander Schouw YT (2006) Postmenopausal
status and early menopause as independent risk factors for cardiovascular
disease: a meta- analysis. Menopause 13: 265-279.
[12] Avis PG, Bergel F, Bray RC (1956) Cellular constituents. The chemistry of
xanthine oxidase. Part III. Estimations of the cofactors and the catalytic
functions of enzyme fractions of cows’ milk. J Chem Soc (Perkins, I). 12191226.
.
[13] Bacon PA, Kitas GD (1994) The significance of vascular inflammation in
rheumatoid arthritis. Ann Rheum Dis 53: 621-622.
[14] Balis, M.E (1976) Uric acid metabolism in Man. Adv Clin Chem 18: 213-246.
[15] Barry B, Martina G, Oliver FG, Jean MD (2004) Apolipoprotein A-I infiltration
in rheumatoid arthritis synovial tissue: a control mechanism of cytokine
production. Arthritis Res Ther 6: 563-566.
.
[16] Belin DC, Morse E, Weinstein A. Whither Westergren (1981) The sedimentation
rate reevaluated. J Rheumatol 8: 331-335.
[17] Biondi-Zoccai GG, Abbate A, Liuzzo G, Biasucci LM (2003) Atherothrombosis,
inflammation, and diabetes. J Am Coll Cardiol 41: 1071-1077.
[18] Blankenhom DH, Johnson RL, Mack WJ, el Zein HA, Vailas LI (1990) The
influence of diet on the appearance of new lesions in human coronary arteries. J
20
Am Med Assoc 263: 1646-1652.
.
[19] Burger D, Dayer JM (2002) High density lipoprotein-associated apolipoprotein
A-1: the missing link between infection and chronic inflammation. Autoimmun
Rev 1: 111-117.
.
[20] Brown WV, Banginsky ML (1972) Inhibition of lipoprotein lipase by an
apoprotein of human very low density lipoprotein. Biochem Biophysics Res
Commun 46: 375-382.
.
[21] Castelli WP, Garrison RJ, Wilson PW, Abbott RD, Kalousdian S, Kannel WB
(1986) Incidence of coronary heart disease and lipoprotein cholesterol levels.
The Framingham study. JAMA 256: 2835-2838.
[22] Cesur M, Ozbalkan Z, Temel MA, Karaarslan Y (2007) Ethinicity may be a
reason for lipid changes and high Lp(a) levels in rheumatoid arthritis. Clin
Rheumatol 26(3): 355-361.
[23] Chambers DE, Parks DA, Patterson G, Roy R, McCord JM, Yoshida S, et al.
(1985) Xanthine oxidase as a source of free radical damage in myocardial
ischemia. J Mol Cell Cardiol 17: 145-152.
[24] Chenaud C, Merlani PG, Roux-Lombard P, Burger D, Harbarth S, Luyasu S, et
al. (2004) low lipoprotein A-I level at intensive care unit admission and systemic
inflammatory response syndrome exacerbation. Crit Care Med 32: 632-637.
[25] Cheng-xing S, Hao-zhu C, and Jun-bo G (2004) The role of inflammatory stress
in acute coronary syndrome. Chinese medical J 117: 133-139.
[26] Chung CP, Oeser A, Solus JF, Avalos I, Gebretsadik T, Shintani A et al. (2008)
Prevalence of the metabolic syndrome is increased in rheumatoid arthritis and is
associated with coronary atherosclerosis. Atherosclerosis 196: 756-763.
[27] Chung HY, Baek BS, Song SH, Kim MS, Huh JI, Shim KH, et al. (1997)
21
Xanthine dehydrogenase / Xanthine oxidase and oxidative stress. Age 20: 127140.
.
[28] Choy E, Sattar N (2009) Interpreting lipid levels in the context of high-grade
inflammatory states with a focus on rheumatoid arthritis: a challenge to
conventional cardiovascular risk actions. Ann Rheum Dis 68: 460-469.
[29] Clavey V, Lestavel-Delattre S, Copin C, Bard JM, Fruchart JC (1995)
Modulation of lipoprotein B binding to LDL receptor by exogenous lipds and
apolipoproteins CI, CII, CIII and E. Arterioscler Thromb Vasc Biol 15: 963971.
[30] Dawson J and Walters M (2006) Uric acid and xanthine oxidase: future
therapeutic targets in the prevention of cardiovascular disease. Br J Clin
Pharmacol 62: 633-644.
.
[31] Dessein PH, Joffe BI, Veller MG, Stevens BA, Tobias M, Reddi K, and Stanwix
AE (2005) Traditional and nontraditional cardiovascular risk factors are
associated with atherosclerosis in RA. J Rheumatol 32: 435-442.
[32] Dieplinger H, Kostner G (1980) The determination of lecithin cholesterol
acryltransferase in the clinical laboratory. Clin Chim Acta 106(3): 319-332.
[33] Fransen J, van Riel PL (2005) The disease activity score and the EULAR
response criteria . Clin Exp Rheumatol 23: S93-S99.
[34] Gabriel SE, Crowson CS, Kremers HM, Doran MF, Turesson C, O'Fallen WM,
Matteson EL (2003) Survival in rheumatoid arthritis: a population- based
analysis of trends over 40 years. Arthritis Rheum 48: 54-58.
[35] Garcia-Gomez C, Nolla JM, Valverde J, Gomez-gerique JA, Castro MJ, Pinto X
(2009) Conventional lipid profile and lipoprotein (a) concentrations in treated
patients with rheumatoid arthritis. J Rheumatol 36: 1365-1370.
22
[36] Georgiadis AN, Papavasiliou EC, Lourida ES, Alamanos Y, KostaraC, Tselepis
A, and Drosos AA (2006) Atherogenic lipid profile is a feature characteristic of
patients with early rheumatoid arthritis: effect of early treatment- a prospective,
controlled study. Arthritis research and therapy 8:R82.
[37] Goodson N: coronary artery disease and rheumatoid arthritis (2002) Curr Opin
Rheumatol. 14: 115-120.
[38] Goodson NJ, Solomon DH (2006) The cardiovascular manifestations of
rheumatic diseases. Curr Opin rheumatol 18: 135-140.
[39] Glibbons GF (1986) Hyperlipidaemia of diabetes. Clin Sci 71: 477-486.
[40] Harrison R, Benboubetra M, Bryson S, Thomas RD, Elwood PC (1990)
Antibodies to xanthine oxidase: elevated levels in patients with acute myocardial
infarction. Cardioscience 1: 183-189.
[41] Havel RJ, Fielding GJ, Olivecrona T (1973) Cofactor activity of protein
components of human very low density lipoprotein in hydrolysis of triglycerides
by lipoprotein lipase from different sources. Biochemistry 12: 1828-1833.
[42] Havel RJ, Eder HA, Bragdon JH (1955) The distribution and chemical
composition of ultracentrifugally separated lipoproteins in human serum. J Clin
Invest 34: 1345-1353.
[43] Hearse DJ, Manning AS, Downey JM (1986) Xanthine oxidase: a critical
mediator of myocardial injury during ischemia and reperfusion. Acta Ohysiol
Scand 548 Suppl: 65-78.
[44] Helmick CG, Felson DT, Lawrence RC, Gabriel S, Hirsch R, Kwoh CK, et al.
(2008) Estimates of the prevelance of arthritis and other rheumatic conditions in
the United States. Part I. Arthritis Rheum 58: 15-25.
[45] Jonas A (2000) Lecithin cholesterol acyltransferase. Biochim Biophys Acta
23
1529: 245-256.
.
[46] Jones SM, Harris CPD, Lioyd J, Stirling CA. Reckless JPD, McHugh NJ (2000)
Lipoproteins and their subfractions in psoriatic arthritis: identification of an
atherogenic profile with active joint disease. Ann Rhem Dis 59: 904-909.
[47] Kimac E, Halabis M, Solski J, Targonska-Stepniak B, Dryglewska M, Majdan M
(2010) Abnormal lipid and lipoprotein profiles in rheumatoid arthritis. Annals
Universitatis Mariae Curie-Sklodowska Lublin – Polonia 2010XXIII,N2,13: 8792.
.
[48] Koopman Wj (2001) Prospects for autoimmune disease: research advances in
rheumatoid arthritis. J Am Med Assoc 285: 648-650.
[49] Kowsalya R, Sreekantha, Vinod Chandran and Remya (2011) Deslipidemia with
altered oxidant-antioxident status in rheumatoid arthritis. International J of
Pharma and Bio Sciences 2(1): 424-428:www.ijpbs.net.
[50] Knowlton N, Wages JA, Cantola MB, Alaupovic P (2012) apolipoproteindefined lipoprotein abnormalities in rheumatoid arthritis patients and their
potential impact on cardiovascular disease. Scand J Rheumatol 41: 165-169.
[51] Krauss RM, Lindgren FT, Wingerd J, Bradley DD, Ramcharan S (1979) Effects
of estrogens and progestins on high density lipoproteins. Lipids 14: 113-118.
[52] Ku IA, Imboden JB, Hsue PY, Ganz P (2009) Rheumatoid arthritis a model of
systemic inflammation driving atherosclerosis. Circ J 73: 977-985.
[53] Kundalic S, Kocic G, Cosic V, Jevtovic-Stoimenov T, Dordevic VB (2003) The
role of xanthine dehydrogenase / xanthine oxidase in atherosclerosis in patient
with hyperlipidemia. Jugoslov Med Biochem 22: 151-158.
[54] LaRosa JG, Levy RI, Herbert P (1970) Specific apoprotein activator for
lipoprotein lipase. Biochem Biophysics Res Commun 41: 57-62.
24
[55] Lems WF, Dijkmans BAC (2000) Rheumatoid arthritis: clinical aspects and its
variants. In: Fireestein GS, Panayi GS, Wollheim FA, eds. Rheumatoid arthritis:
new frontiers in pathogenesis and treatment. New York: Oxford University
Press. pp 213- 225.
[56] Lind L (2003) Circulating markers of inflammation and atherosclerosis.
Atherosclerosis 169(2): 203-214.
[57] London MG, Muirden KD, Hewitt JV (1963) Serum cholesterol in rheumatic
disease. BMJ 1: 1380-1383.
[58] Lourida EV, Georgiadis AN, Papavasilious EC, Papathhanasiou AI, Drosos EA,
Tselepis LD (2007) Patients with early rheumatoid arthritis exhibit elevated auto
antibody titers against mildly oxidized low- density lipoprotein and exhibit
decreased activity of the lipoprotein- associated phospholipase A2. Arithritis Res
Ther 9(1): R19.
[59] Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (1951) Protein measurement
with Folin phenol reagent. J Biol Chem 193: 265-275.
[60] Magkos F, Wang X, Mittendorfer B (2010) Metabolic actions of insulin in men
and women. Nutrition 26(7-8): 686–693. doi:10.1016/j.nut.2009.10.013.
[61] Mccord JM (2000) The evolution of freeradicals and oxidative stress. Am J Med
108: 652-659.
[62] Mendivil CO, Rimm EB, Furtado J, Chiuve SE, Sacks FM (2011) Low- density
lipoproteins containing apolipoprotein C-III and the risk of coronary heart
disease. Circulation 124: 2065-2072.
[63] Metsios G, Stavropoulos-Kalinoglou A, Sandoo A, Veldhuijzen van Zanten
JJCS, Toms TE, John H and Kitas GD (2010) Vascular function and
inflammation in rheumatoid arthritis : the role of physical activity. Open
25
Cardiovasc Med J 4: 89-96.
[64] Myasoedova E, Crowson CS, Kremers HM, Fitz-Gibbon PD, Themeau TM,
Gbriel SE (2010) Total cholesterol and LDL levels decrease before rheumatoid
arthritis. ANN Rheum Dis 69(7): 1310-1314.
[65] Ng YLE, Lewis WHP (1994) Circulating immune complexes of xanthine oxidase
in normal subjects. Br j biomed Sci 51: 124-127.
[66] Nicolay A, Lombard E, Arlotto E, Saunier V, Lorec-Penet A, Lairon D, Portugal
H (2006) Evaluation of new apolipoprotein C-II and apolipoprotein C-III
automatized immunoturbidimetric kits. Clin Biochem 39: 935-941.
[67] Nikkila EA, Marja-Riita MD, Taskinen MD, Timosane MD (1987) Plasma highdensity lipoprotein concentreation and subfraction distribution in relation to
triglyceride metabolism. Am Heart J 113:543-548.
[68] Nishino T (1994) The conversion of xanthine dehydrogenase to xanthine oxidase
and the role of the enzyme in reperfusion injury. J Biochem 16: 1-6.
[69] Nurmohamed MT (2007) Atherogenic lipid profiles and its management in
patients with rheumatoid arthritis. Vascular Health and Risk management 3(6):
845-852.
[70] Oliviero F, Sfriso P, Baldo G, Dayer JM, Giunco S, Scanu A, et al. (2009)
Apolipoprotein A-1 and cholesterol in synovial fluid of patients with rheumatoid
arthritis, psoriatic arthritis and osteoarthritis. Clin Exp Rheumatol 27(1): 79-83.
[71] Park YB, Choi HK, Kim MY, Lee WK, Song J, Kim DK, Lee SK (2002) Effects
of antirheumatic therapy on serum lipid levels in patients with rheumatoid
arthritis: prospective study. Am J Med 113: 188-193.
[72] Park YB, Lee SK, Lee WK, Suh CH, Lee CW, Lee CH, et al. (1999) Lipid
profiles in untreated patients with rheumatoid arthritis. J Rheumatol 26(8):
26
1701-1704.
[73] Pincus T, Callahan L (1986) Taking mortality in rheumatoid arthritis seriouslypredictive markers, socioeconomic status and comorbidity. J Rheumatol 13: 841845.
.
[74] Raghuvanshi R, Kaul A, Bhakuni P, Mishra A, Misra MK (2007) Xanthine
oxidase as a d marker of myocardial infarction. Indian journal of Clinical
Biochemistry 22(2): 90-92.
[75] Rees MD, Kennett EC, Whitelock JM, and Davies MJ (2008) Oxidative damage
to extracellular matrix and its role in human pathologies. Free Radical Biology
and Medicine 44(12): 1973-2001.
[76] Regnstron J, Nilsson J, Tornwall P, Landdou C, Hamsten A (1992) Susceptibility
to low density lipoprotein oxidation and coronary atherosclerosis in man. Lancet
339: 883-887.
[77] Reilly PA, Cosh JA, Maddison PJ, Rasker JJ, Silman AJ (1990) Mortality and
survival in rheumatoid arthritis: a 25 year prospective study of 100 patients. Ann
Rheum Dis 49: 363-369.
[78] Rohrer L, Hersberger M, and von Eckardstein A (2004) high density lipoproteins
in the intersection of diabetes mellitus, inflammation and cardiovascular disease
current. Opion in Lipidology 15: 269-278.
[79] Ross R (1999) Atherosclerosis-an inflammatory disease. N Engl J Med 340: 115126.
[80] Saito M, Ishimitsu T, Minami J, Ono H, Ohrui M, Matsuoka H (2003) Relations
of plasma high-sensitivity C-reactive protein to traditional cardiovascular risk
factors. Atherosclerosis 167(1): 73-79.
[81] Sattar N, McCarey DW, Cappel H, McInnes IB (2003) Explaining how 'high-
27
grade' systemic inflammation accelerates vascular risk in rheumatoid arthritis.
Circulation 108: 2957-2963.
[82] Shoenfeld Y, Gerli R, Doria A, Matsuura E, Cerinic MM, Ronda N et al. (2005)
Accelarated atherosclerosis in autoimmune rheumatic disease. Circulation 112:
3337-3347. .
[83] Situnayake RD, Thurnham DI, Kootathep S, Chirico S, Lunee J, Davis M, et al.
(1991) Chain breaking antioxidant status in rheumatoid arthritis: clinical and
laboratory correlates. Ann Rheum Dis 50: 81-86.
[84] Soubrier M, Dougados M (2006) Atherome et polyarthrite rhunatoide. Rev Med
Int 27: 125-136.
[85] Solomon DH, Curhan GC, Rimm EB, Cannuscio CC, Karlson EW (2004)
Cardiovascular risk factors in women with and without rheumatoid arthritis.
Arthritis Rheum 50: 3444-3449.
[86] Solomon DH, Karlson EW, Rimm EB, Cannuscio CC, Mandl LA, Manson JE, et
al. (2003) Cardiovascular morbidity and mortality in women diagnosed with
rheumatoid arthritis. Circulation 107: 1303-1307.
[87] Takayama M, Itoh S, Nagasaki T, and Tanimizu T (1977) A new enzymatic
method for determining of serum choline containing phospholipids. Clin Chim
Acta 79: 93-98.
[88] Tian L, Xu Y, Fu M, Peng T, Liu Y and Long S (2011) The impact of plasma
triglyceride and apolipproteins concentrations on high-density lipoprotein
subclasses distribution. Lipids in Health and disease 10: 17 doi:10.1186/1476511X-10-17.
[89] Trinder P (1969) Determination of glucose in blood using glucose oxidase with
an alternative oxygen acceptor. Ann Clin Biochem 6: 24-26.
28
[90] Van Doornum S, McGoll G, Wicks IP (2002) Accelerated atherosclerosis: an
extraarticular feature of rheumatoid arthritis. Arthritis Rheum 46: 862-873.
[91] Van HalmVP, Nielen MMJ, Nurmohamed MT, van Schaardenburg D, Reesink
HW, Voskuyl AE, et al. (2007) lipids and inflammation: serial measurement of
the lipid profile of blood donors who later develop RA. Ann Rheum Dis 66:
184-188.
[92] van Wietmarschen H, and van der Greef J (2012) Metabolite Space of
Rheumatoid Arthritis . British Journal of Medicine and Medical Research 2(3):
469-483.
[93] Walldius G, Jungner I (2006) The apo B/apoA-A ratio: a strong new risk factor
for cardiovascular disease and a target for lipid-lowering therapy a review of the
evidence. J Intern Med 259: 493-519.
[94] Wang CS, McConathy WJ, Kloer HU, Alaupovic P (1985) Modulation of
lipoprotein lipase activity by apolipoproeins. Effect of apolipoprotein C-III. J
Clin Invest 75: 384-390.
[95] Watson DJ, Rhodes T, and Guess HA (2003) All-cause mortality and vascular
events among patients with rheumatoid arthritis, osteoarthritis, or no arthritis in
the UK General Practice Research Database. J Rheumatol 30: 11996-1202.
[96] Wolf F, Freundlich B, Straus WL (2003) Increase in cardiovascular and
cerebrovascular disease prevelance in rheumatoid arthritis. J. Rheumatol 30: 3640.
[97] Walldius G, and Jungner I (2004) Apolipoprotein B and apolipoprotein A-I: risk
indicators of coronary heart disease and targets for lipid-modifying therapy. J
internal Medicine 255: 188-205.
[98] Yamada T, Ozawa T, Gejyo F, Okuda Y, Takasugi K, Hotta O, Itoh Y (1998)
29
Decrease serum apolipoprotein AII/AI ratio in systemic amyloidosis. Ann
Rheum Dis 57: 249-251.
[99] Yoo WH (2004) Dyslipoproteinemia in patients with active rheumatoid arthritis:
effects of disease activity, sex, and menopausal status on lipid profiles. J.
Rheumatol 31(9): 1746- 1753.
[100] Zhang B, Pu SX, Li BM, Ying JR, Song X W, and Gao C (2010) Comparison
of serum Apolipoprotein A-I between Chinese multiple sclerosis and other
related
autoimuune
disease.
Lipid
in
health
and
disease
9:34
Doi:10.1186/1476-511X-9-3.
[101] Zrour SH, Neffeti FH, Sakly N, Jguirim M, Korbaa W, Younes M, et al. (2011)
lipid profile in Tunisian patients with rheumatoid arthritis. Clin Rheumatol 27
April DOI 10.1007/s10067-011-1755-9.
Declaration of interest
The authors report no declaration of interest.
30
Table 1: Clinical and biochemical characteristics of controls and patients with
rheumatoid arthritis, male and female subjects.
Parameters
Males
Females
Control
RA+
RA-
Control
RA+
RA-
Number
55
32
31
56
31
33
Age (years)
40.1±9.6
39.9±9.6
38.1±11.6
39.6±9.1
40.8±8.1
38.9±10.3
Height cm
162.9±9.6
161.8±7.9
160.6±10.9
163.6±5.7
161.2±8.9
160.6±10.9
Weight Kg
68.8±8.1
67.3±4.8
66.9±8.9
69.9±6.3
68.9±3.3
70.3±8.3
BMI (kg/m2)
27.3±4.6
28.1±7.7
27.8±4.2
26.1±3.3
27.4±8.3
26.9±10.1
ESR (mm/h)
10.8±6.03
66.9±42.6**
43.3±28.6*
11.9±5.02
67.1±43.2**
42.6±29.8*
CRP (mg/dl)
-
+
+
-
+
+
IgM
0/0
45/13
44/13
0/0
46/13
44/13
95.9±6.8
94.8 ±7.2
92. 9±9.9
91.81±8.3
98.6± 9.1
100.3±11.6
4.2±1.6
7.2±1.10*
6.0±1.6*
4.0±1.0
6.9±1.6*
6.6±1.3*
rheumatoid
factor (+/-)
Glucose
mg/dL
Uric acid
mg/dL
BMI: body mass index, ESR: erythrocytes sedimentation rate, CPR: C-reactive protein.
*P < 0.001 significantly different from the corresponding control.
** P < 0.0001, between RA+ compare to RAValues represent the means ± standard deviation (SD)
BMI = weight < [kg/height (m)2]
31
Table 2: Serum Lipids and lipoprotein concentrations (mg/dL) in control and in
rheumatoid arthritis male and female subjects.
Variable
Males
Females
Control
RA+
RA-
Control
RA+
RA-
Number
55
32
31
56
31
33
Total Cholesterol
203±27.3
240.3±38.16*
239.1±30.1*
170.1±18.1c
197.8±23.8*a
186.2±20.9*†b
VLDL-C
30.3±10.7
37.6±12.3*
39.8±13.6**
16.2±5.6c
20.3±6.8**a
19.6±4.8**b
LDL-C
116.15±21.5
162.69±32.6*
158.9±29.6*
96.5±13.1c
140.1±28.3*a
126.9±14.1†b
HDL-C
56.13±6.15
38.10±2.7**
40.10±3.6**
59.30±6.3
38.50±6.6**
39.60±7.2**
HDL2-C
23.79±2.6
11.50±3.2*
13.60±4.1*
24.10±2.6
12.90±43.1*
13.10±4.1*
HDL3-C
33.50±2.7
26.1±3.0**
27.60±2.8**
34.9±3.1
25.8±3.9**
26.10±3.8**
Total triglyceride
119.2±17.6
186.3±20.6**
178.6±18.9**
93.6±18.3c
150±17.2* a*
115.8±19.1†b
VLDL-TG
75.2±8.7
119.2 ±10.1*
115.9±11.2*
47.3±16.2c
87..1± 13.1*a
64..9±15.1†b
LDL -TG
28.1±5.1
40.6±7.2**
39.6±8.2**
27.6±7.2
40.3±4.3*
30.9±6.2*†b
HDL-TG
17.2±6.1
24.9±6.2*
23.9±5.5*
18.3±4.2
24.1±2.7*
22.3±5.2†b
Phospholipid Total
193.3±30.3
260.3±32.3*
256.6±29.6*
168.3±16.3c
230.6±29.6*a
171.3±17.1†b
TC
TG
Values represent the means ± standard deviation (SD) in milligrams per deciliter
VLDL: very low density lipoprotein, LDL: low-density lipoprotein, HDL: high-density lipoprotein,
TC: total cholesterol, TG: triglyceride, TTG: total triglyceride.
*P < 0.0001, **P < 0.001 significantly different from the corresponding control.
†
P< 0.01 between RA+ and RA- patients ( male and Female)
a
P< 0.001 between RA+ male and female
b
c
P< 0.001 between RA- male and female
P < 0.0001 between control group (male and female) lipoprotein densities: VLDL, d < 1.006 gml -1;
LDL, d = 1.006-1.063 gml-1; HDL2, d = 1.063-1.125 gml-1; HDL3, d = 1.125-1.21 gml-1.
32
Table 3: Serum Apolipoprotein A-1, A-II, B, C-II and C-III concentrations of
patients with rheumatoid arthritis and controls.
Males
Number
Serum Apo
Females
Control
RA+
RA-
Control
RA+
RA-
55
32
31
56
31
33
150.3±16.3
110.7±13.3*
109.6±14.3*
133.7±11.6c
107.6±20.1*
106.3±19.1*
123.6±11.3
86.3±14.6*
84.9 ±17.6*
118.6±10.6c
83.6±10.3**
80.9±11.6**
50.9±3.7
39.1±3.6
40.1±5.2
48.6±8.6
40.1±7.6
39.6±9.1
110.6±9.6
132.3±10.8**
129.6±12.1**
98.6±7.6 c
125.6±10.6**
92.3±11.**ab
95.9±12.8
115.2±10.8**
113.9±13.**6
82.3±3.3 c
103.7±9.6**
103.6±150.6**ab
4.0±0.08
4.2±0.1
3.8±0.11
3.8±0.06
4.2±0.13
3.9±0.09
6.8±0.09
8.6±0.14*
7.8±0.18*
6.0±0.19
8.9±0.1*
7.2±0.01*a
A-I
HDL Apo
A-I
Serum Apo
A-II
Serum
ApoB
LDL-Apo
B
Serum apo
C-П
Serum apo
C-ПI
Values represent the means ± standard deviation (SD) in milligrams per deciliter, HDL: high-density
lipoprotein, LDL: low-density lipoprotein, apolipoproteins, Apo A-1, Apo A-II, Apo B, Apo C-II, and
Apo C-IП.
*P< 0.0001, **P< 0.001: significantly different from the corresponding control group.
a
P< 0.001 between RA+ and RA- patients (male and Female).
b
c
P< 0.001 between RA- male and female.
P < 0.001 significantly different between control group (male and female) .
33
Table 4: Serum lecithin cholesterol acyltransferase (LCAT), serum and synovial
xanthine oxidase (XO) activities of patients with rheumatoid arthritis and
controls.
Males
Females
Control
RA+
RA-
Control
RA+
RA-
Number
55
32
31
56
31
33
Serum
127.8±26.7
99.9±13.3*
109.6±30.1*
125.3±23.7
106.7±29.9**c
110.6±28.1**
0.0090±0.003
0.056±0.0046**
0.04±0.004**a
0.0091±0.003
0.063±0.009**
0.048±0.0024**a
NA
98.9±40.6
78.1±29.61 a
NA
100.46±45.8
82.81±35.61 a
LCAT
mg/dl
Serum XO
units/mg
protein
Synovial
XO,
nmole.min1.mg-1
*P< 0.001, **P< 0.01 significantly different from control
a,
P< 0.001 between RA+ and RA- in male and female groups.
34
Table 5: Total IgG and IgM titers in sera and synovial fluid of patients with
rheumatoid arthritis ( RA+) , other joint inflammation (RA-), and healthy
volunteers, using SRIDA**
Males
Number
Blood
Total
Females
Control
RA+`
RA-
Control
RA+`
RA-
55
32
31
56
31
33
1.61±0,67
2.41±1.61*a
3.79±0.10*a
1.51±0.41
2.61±1.31*a
3.51±0.13*b
NA
1.01±0.61c
0.61±0.22
NA
0.88±0.40 c
0.49±0.31
12.55±10.36
25.61±10.31*
11.9±5.1
22.1±9.1*
14.76±7.2*
NA
14.21±3.9c
NA
13.91±4.0 c
9.81±2.11
IgM
Synovial
(mg/ml)
Blood
Total
18.67±7.2*
IgG
Synovial
10.29±3.0
(mg/ml)
RA+= rheumatoid arthritis latex agglutination positive
**SRIDA= single radial immunodiffusion assay
*P< 0.001, significantly different from the corresponding control groups
a
P< 0.001, between RA+ and RA- patients( male and female)
b
P< 0.001, between RA- male and female patients
c
P< 0.01, between RA+ male and female
35
Table 6: Ratios of lipid and lipoprotein fractions in control groups and patients with
rheumatoid arthritis
Males
Females
Control
RA+
RA-
Control
RA+
RA-
Number
55
32
31
56
31
33
T-C/HDL-C
1.95±0.30
6.40±0.51*
5.30±0.65*a
2.83±0.31
5.90±0.61*
4.31±0.035*a
LDL-C/HDL-
1.67±0.31
3.81±0.59*
3.31±0.90*
1.33±0.41
3.61±0.32*
3.71±0.29*
0.39±0.03
0.41±0.06
0.37±0.03
0.40±0.021
0.38±0.04
0.36±0.03
T-C/Apo B
2.61±0.40
2.14±0.30
2.00±0.23
2.31±0.31
2.00±0.22
1.90±0.23
Apo
0.31±0.09
1.08±0.21*
1.03±0.17*
0.29±0.71
0.98±0.18*
0.91±0.15*
4.01±0.061
10.46±3.01*
9.80±2.91*
3.61±0.081
9.81±3.10*
8.91±3.21*
0.71±0.01
0.47±0.03*
0.52±0.08*
0.69±0.09
0.51±0.09*
0.49±0.08*
0.30±0.04
0.43±0.036
0.50±0.04
0.27±0.033
0.48±0.05
0.47±0.048
C
HDL-C/Apo
A-I
B/.Apo
A-I
LDLC/HDL2-C
HDL2C/HDL3-C
Apo C-III/TG
Results are means ± SD
HDL-C: high density lipoprotein cholesterol, LDL-C: low density lipoprotein cholesterol, T-C: total
cholesterol, Apo A-I, Apo A-II and Apo B: apolipoproteins
*P < 0.001 significantly different from control subjects
a
P < 0.01 between RA+ and RA- in both male and female patients
36