HLA‐C locus and genetic susceptibility to psoriatic arthritis in Romanian population

We determined the distribution of human leukocyte antigen-C (HLA-C) allelic groups in a cohort of psoriatic arthritis (PsA) patients and a control population of Romanian ethnicity. A nominal association of HLA-C*06 with susceptibility to PsA was observed [P = 0.014, pcorr > 0.05, odds ratio (OR) 2.1, 95% confidence interval (CI) 1.08–4.46]. When subanalyzing data according to PsA clinical phenotypes, association was noticed between HLA-C*06 and PsA with psoriasis onset before 40 years (pcorr = 0.013, OR 3.7, 95% CI 1.58–9). This first report from Romania confirmed the association of HLA-C*06 with type I psoriasis in PsA patients. Other study findings, such as the relationship between HLA-C*06 and spondylitis or the protective effect of HLA-C*07 for the polyarthritis clinical phenotype of PsA, are of preliminary character and require verification.