#389
Time to HIV-1 Seroconversion Similar Among Patients with Acute HIV-1 Infection;
but there are Exceptions…
Susan
Morpeth1,
Thielman1,
Giner1,
Menezes2,
Fiscus2,
Tomaras1,
Pilcher2,
Lennox3,
Eron2,
Nathan
Julia
Prema
Susan
Georgia
Christopher
Jeffrey
Joseph
Charles
1. Duke University Medical Center, Durham, NC, USA, 2. University of North Carolina, Chapel Hill, NC, USA, 3. Emory University, Atlanta, GA, USA.
Case Study: a 49 year old man with acute HIV-1 infection
ABSTRACT
METHODS The Duke-UNC-Emory Acute HIV Research Consortium studies adult patients with symptomatic acute HIV-1 infection diagnosed within 30
days of seroconversion. This prospective cohort enrolled 72 subjects from 1998-2005. Associations were sought between initial ELISA status and
demographic variables, viral load (VL), nadir CD4 count and time to seroconversion using Wilcoxon rank-sum and Fisher’s exact tests. We report one
case in which seroconversion took >1 year to occur.
RESULTS At the time of acute HIV-1 diagnosis, 44 of 72 patients had a negative ELISA. Median time (25-75th quartiles) from symptom onset to first
ELISA test: negative ELISA = 9 (5-15) days; reactive ELISA = 25 (16-37) days, p<0.0001. Median initial VL was higher among negative ELISA patients
compared to reactive ELISA patients (5,649,238 vs. 310, 525 copies/mL, p<0.0001). Patients with a negative ELISA were more likely to be non-Caucasian
(p=0.0286). Nadir CD4 counts were comparable (medians 393, 433, p=ns) as was time to first positive ELISA (medians 26 days, 25 days, p=ns). A greater
proportion of cases who were ELISA negative at diagnosis were identified in 2004-5 than in the preceeding six years. A 22 yo man presented with acute
HIV-1 infection (VL>10 million copies/mL) and had repeatedly negative HIV-1 ELISA tests over the ensuing year, during which he had PCP. He
seroconverted only after initiation of effective antiretroviral therapy. Antibody responses to prior tetanus and diphtheria immunization were normal.
His HLA type was not one associated with abnormal responses (HLA-B72). Plasma-derived virus (at initial diagnosis) used both CCR5 and CXCR4 coreceptors.
CONCLUSIONS Subjects diagnosed with acute HIV infection while ELISA-negative had a significantly higher VL than those who had already
seroconverted, but nadir CD4 counts did not differ. Median time to a reactive HIV-1 ELISA from onset of symptoms also did not differ. In 2004-5 more
cases were identified through the NC State program, meaning they were ELISA negative and HIV RNA PCR positive. One patient who rapidly
progressed to AIDS did not seroconvert for a full year, despite evidence of functional B cell responses to non-HIV antigens. Virus targeting of HIV-1
specific T cells that augment specific B cell responses may explain this observation.
BACKGROUND
•Time to HIV-1 seroconversion is established at <1 month in modern cohorts and is dependent on ELISA technology used.
•Typical time from HIV-1 infection to AIDS is about 12 years but there are rapid progressors and slow progressors.
•A high viral load set point and low CD4 nadir is well known to correlate with poor prognosis but replicative capacity of wild-type virus, drug-resistant
mutations and co-receptor use are all viral characteristics that are likely to come into play.
•A broad and strong cytotoxic T lymphocyte (CTL) response results in prompt virological control and a good antibody response, although there will be
eventual viral escape in most people. A poor CTL response may be associated with a poor antibody response and slow to no control of virological
replication and CD4 destruction.
Sept 03
Nov 03
Dec 03
Fatigue,
anorexia,
weight loss.
HIV-ab neg PCP
Jan 04
Apr 04
HIV-ab neg,
HIV-ab neg Diarrhea
VL>750,000
Wt 185 lbs
VL>750,000 Wt 178lbs
HIV-ab neg,
VL>10million
HIV-ab neg,
CD4 2
HIV-ab neg
VL>750,000
Tropism
assay
VL>750,000
CD4 3
TDF/LMV/EFV
commenced
May 04
Jun 04
Sep 04
Dec 04
Delusions HIV-ab neg
Back to work
Wt 233lbs
HIV-ab
neg
HIV-ab pos
VL<50
VL 135
CD4 234
VL 2250
CD4 50
VL 2880
Phenosense
assay
•Plasma derived virus isolates from the subject were titrated on U87 cell lines stably expressing CD4 alone, CD4 and CCR5, or CD4 and CXCR4 to
assess their ability to use CCR5 and/or CXCR4 for productive infection.
Phone: 919 684 3916
p-value
(n = number of subjects with data available)
Median
(Interquartile range)
Median
HIV-1 RNA at initial ELISA (copies/mL)
n=37
5,649,238
(2,322,724 - 16,866,713) 310,525
(140,538 – 1,682,818)
<0.0001
Days from symptoms to initial ELISA
n=72
9
(5 – 15)
25
(16 – 37)
<0.0001
Days from symptoms until CART* initiated
n=63
26
(19 – 36)
38
(23 – 54)
0.0148
Number
(Percent)
Number
(Percent)
25
(57%)
8
(29%)
(Interquartile range)
0.0286
Characteristics Not Significantly Associated with a Negative Initial HIV-1 ELISA at Time of Diagnosis of
Acute HIV-1 Infection
Phenosense GTTM in April 2004
Co-receptor Use of Plasma-derived Virus from
Case Study Subject in March 2004
(Interquartile range)
Median
(Interquartile range)
•Clade B
Age (years)
n=72
29
(23 – 36)
32
(23 – 45)
0.2745
393
(266 – 589)
433
(365 – 656)
0.3542
Other assays performed:
CD4 T-lymphocyte nadir recorded in 8
weeks from symptom onset (cells/mm3)
n=46
•Adequate levels of IgG, IgA, IgM, IgE, Diphtheria and Tetanus
antibodies in April 2004
Days from symptoms to positive ELISA
n=63
26
(20 – 34)
25
(17 – 40)
0.8724
Number
(Percent)
Number
(Percent)
38
(86%)
26
(93%)
•HIV-1 antibody testing performed using Vironostika ELISA kit
from bioMerieux, Durham, NC and confirmed as negative from
May and June 2004 samples using Genetic SystemsTM by BioRad, Redmond, WA
CCR5
10000
CXCR4
p-value
Median
•Resistance mutations: M184M/I/V, K103N, V108V/I, L33V
(K103N and L33V were later found to have been present in a
pre-treatment sample from December 2003)
100000
Initial ELISA Positive (n=28)
(n = number of subjects with data available)
10000000
1000000
Initial ELISA Negative (n=44)
•Replicative capacity 15%
Male gender
n=72
0.4705
1000
•HIV-1 Western Blots (Bio-Rad) negative or indeterminate until
seroconversion in September 2004
100
Subject
R5 Control
Replication Competent Virus Isolates
•HLA-B72 (not known to be associated with HIV-1 disease
progression)
X4 Control
Demographics of a Cohort of 72 Acutely HIV-1 Infected Subjects
in North Carolina
Median Interquartile range
Age (years)
•His virus was characterized by subtype, replicative capacity, genotype and phenosense assay by Monogram Biosciences, South San Francisco, CA.
Fax: 919 684 8519
Initial ELISA Positive (n=28)
Non-white ethnicity
n=72
ABC/LMV/ZDV
+LPV/r
RESULTS
•We describe a patient with primary HIV-1 infection who was persistently seronegative for 12 months, seroconverting only after achieving virological
control with effective antiretroviral therapy.
morpe001@mc.duke.edu
Initial ELISA Negative (n=44)
CD4 57
HIV-ab = HIV-1 antibody by Vironostika HIV-1 ELISA, bioMerieux, Durham, NC
•There have been case reports of patients with rapidly progressive HIV disease with seronegative infection by ELISA and Western blot, some of whom
have seroconverted only after virological control by antiretroviral therapy.
METHODS
Mar 04
Duke University Medical
Center, Durham, NC
27710
Characteristics Significantly Associated with a Negative Initial HIV-1 ELISA at Time of Diagnosis of Acute HIV1 Infection
Timeline
TCID50 (TCID = Tissue culture infective dose)
BACKGROUND Factors influencing time to HIV-1 seroconversion are not well established. Rare case reports describe patients with prolonged periods
prior to HIV-1 antibody generation. Such patients may have a rapidly progressive course but it is not known if this is due to increased viral virulence or
host factors.
Hicks1
Susan Morpeth MBChB
Number of Cases of Acute HIV-1 Diagnosed
while ELISA-Negative or Positive by Year of
Diagnosis
30
23 - 41
Number
Percent
Male gender
64
89%
Non-white ethnicity
33
46%
*CART = combination antiretroviral therapy
CONCLUSIONS AND DISCUSSION
•Subjects diagnosed with acute HIV-1 infection while ELISA-negative had a significantly higher viral load at time of first evaluation than those who had
already seroconverted, but nadir CD4 counts did not differ.
•Median time to a reactive HIV-1 ELISA from onset of symptoms in the cohort also did not differ by initial ELISA status, indicating that initially
seronegative subjects did not have a longer window period.
•Persons of non-white ethnicity were more likely to be diagnosed while still HIV-antibody negative, perhaps because the diagnosis of HIV was
considered earlier.
•The increasing proportion of cases diagnosed while still ELISA negative in 2004-5 was likely a consequence of increasing numbers of cases of acute HIV1 in NC being identified through the STAT program which teams an older ELISA assay with HIV RNA PCR to accomplish this goal.
•Our case study subject rapidly progressed to AIDS and did not seroconvert for a full year, despite evidence of functional B cell responses to non-HIV
antigens. We speculate that virus targeting of HIV-1 specific T cells that augment specific B cell responses may explain this rapid progression.
Year of initial ELISA
1998
1999
2000
2001
2002
2003
2004
2005
Total cases
Initial ELISA negative
0
2
2
5
3
3
13
16
44
•The case study subject had dual tropic virus in March 2004. If he had dual tropic virus initially this may partly explain his propensity for rapid
progression, or rapid progression and immune collapse may be why his virus was able to become dual tropic early on.
•ELISA’s used were Vironostika by bioMerieux, Durham, NC, Genetic Systems
by Bio-Rad, Redmond, WA, Abbott HIVAB-1 and 1/2 by Abbott
Laboratories, IL. Subjects referred from the Screening and Tracing Active Transmission (STAT) program (pooled HIV-1 RNA PCR testing of ELISAnegative samples from NC State testing sites) all had ELISA’s done using the Vironostika HIV-1 immunoassay.
Initial ELISA positive
4
7
3
4
1
1
3
5
28
•Virological control with effective CART may facilitate seroconversion in such cases. Could seroconversion be a marker of improved cytotoxic T
lymphocyte responses?
Total cases
4
9
5
9
4
4
16
21
72
LIMITATIONS
•Associations were sought between initial ELISA status and demographic variables, viral load (VL), nadir CD4 count, time to seroconversion and year
of diagnosis using Wilcoxon rank-sum and Fisher’s exact tests in JMP 5.1, SAS Institute, Cary, NC.
The number of cases of acute HIV-1 diagnosed while still ELISA-negative was significantly greater in 2004-5 (29/37, 78%)
than in the preceeding 6 years (15/35, 43%), p=0.0034.
•The case was compared to our cohort of patients from the Duke-UNC-Emory Acute HIV Consortium database, consisting of patients referred to HIV
clinic before or within 30 days of seroconversion from January 1998 until December 2005.
TM
ACKNOWLEDGEMENTS:
•More frequent monitoring of HIV-1 ELISA, HIV-1 RNA and CD4 counts than is practical in a clinical setting would lead to more precise results.
•Unfortunately peripheral blood mononuclear cells were not available from the case subject to assess his HIV-specific cytotoxic T lymphocyte responses.
•The tropism assay shown is from March 2004, after 3 months of ineffective antiretroviral therapy (ART) and is being repeated on plasma from December 2003, prior to any exposure to ART.
The authors gratefully acknowledge the assistance of Monogram Biosciences with the genotypic and phenotypic assays of the HIV-1 virus isolated from the case study subject. The assistance of JoAnn Kuruc and Kara McGee with data compilation from the Duke-UNC-Emory Acute HIV Consortium cohort is also greatly appreciated.