EUROPEAN IMMUNOGENETICS AND
HISTOCOMPATIBILITY CONFERENCE (EFI)
May 15-18, 2010, Florence, ITALY
oliviapopa@yahoo.com
ASSOCIATION OF HLA-C*06 WITH SUSCEPTIBILITY TO
PSORIATIC ARTHRITIS AND ITS CLINICAL PHENOTYPE IN
ROMANIA
O. M. Popa1, L. Popa2, M. I. Dutescu3, M. Bojinca4, V. Bojinca5, C. Ciofu4, C. Bara1,
F. Mrazek6, M. Petrek6
1Department of Immunology and Pathophysiology, Faculty of Medicine, University "Carol Davila", Bucharest, Romania
2Molecular Biology Department, Grigore Antipa National Museum of Natural History, Bucharest, Romania3National
Hematology Institute Prof. Dr. C.T. NICOLAU, Bucharest, Romania4Department of Rheumatology, Faculty of Medicine,
University "Carol Davila", "I.C. Cantacuzino" Hospital, Bucharest, Romania 5Department of Rheumatology, Faculty of
Medicine, University "Carol Davila", ”St. Maria” Hospital, Bucharest, Romania6Laboratory of Immunogenomics and
Proteomics, Department of Immunology, Palacky University, Olomouc, Czech Republic
INTRODUCTION

Psoriatic arthritis (PsA) is a complex disease
characterized by inflammation of the skin
(psoriasis) and joints (arthritis).
Genome-wide association study on PsA Caucasian
patients showed strong association with HLA class
I region (1).
Studies concerning HLA-C locus showed positive
association of C*06 with psoriatic arthritis in some
populations, but no association in others.


1. Liu Y, PLoS Genet. 28; 4(3):e1000041, 2008
AIMS
The aim of this study was to determine the
influence of HLA-C alleles on susceptibility to
psoriatic arthritis in Romanian population and to
compare the distribution of HLA-C alleles among
different disease subtypes.
SUBJECTS AND METHODS





57 Romanian psoriatic arthritis patients diagnosed
according to the Moll & Wright diagnostic criteria;
124 Romanian unrelated healthy control subjects;
We have established three subgroups of patients
according to the following main disease
phenotypes: arthritis with axial involvement
(spondylitis) – 30%, oligoarthritis (no more than 4
joints affected) – 21%, polyarthritis (5 or more
joints affected) – 49%;
The HLA-C genotyping was performed by
polymerase chain reaction with sequence specific
primers (PCR-SSP) using HLA-C-SSP low resolution
kit (Olerup, Sweden);
The data were analyzed using the OpenEpi
Collection of Epidemiologic Calculators Version
2.3. The significance of the association (p<0.05)
was determined using the Mid-P exact test and
Bonferroni correction was applied for the number
of compared HLA-C allelic groups.
RESULTS




We have found an association between HLA-C*06 and
psoriatic arthritis (Pcorr=0.03, OR 2.9).
A weak negative association (“protective effect”) with
PsA was found for HLA-C*04, but this was not
significant after correction (pun=0.04, pcorr=NS).
In the subanalysis according to the PsA phenotypes, the
patients with axial form of arthritis (spondylitis) showed
an increased frequency of HLA-C*06 (pcorr=0.03, OR
5.1).
There was a lower phenotype frequency of HLA-C*07 in
polyarthritis group compared with controls (26% versus
46), but not significant after correction (P=0.03)
Patients;
47,0%
0 ,5
0 ,4 5
0 ,4
0 ,3 5
Patients;
33,3%
0 ,3
0 ,2 5
0 ,2
0 ,1 5
Controls;
14,5%
Controls;
14,5%
0 ,1
0 ,0 5
0
PsA
PsA Spondylitis
Figure 1. Comparison of HLA-C*06 phenotype frequency in psoriatic arthritis (PsA)
patients/controls (P=0.0025, Odds Ratio=2.9, 95% CL 1.4-6.2) and PsA spondylitis
subgroup/controls (p=0.0021, Odds Ratio=5.1, 95% CL 1.7-15.5).
CONCLUSION
This is the first study reporting the HLA-C alleles distribution in psoriatic arthritis patients in Romania;
We confirmed here in the Romanian population the association of HLA-C*06 with psoriatic arthritis
association found previously in other populations;
In Romanian population HLA-C*06 allelic group is associated with axial form of psoriatic arthritis;
Genetic studies regarding the HLA-C locus in psoriatic arthritis point to the fact that the HLA-C gene
confers a genetic risk for this disease at least in some ethnic groups.
GRANT SUPPORT: CNCSIS-UEFISCSU, project number PNII-IDEI 311/2007, ROMANIA and IGA UP project
no. LF_2010_008, CZECH REPUBLIC