Human leukocyte antigen distribution in Israeli patients with psoriatic arthritis

Objectives. This study was designed to investigate the distribution of human leukocyte antigen (HLA) classes I and II in a group of Israeli Jewish patients with psoriatic arthritis (PsA) and identify HLA markers related to disease manifestation in PsA. Patients and methods. Human leukocyte antigens class I and class II (both serologically and from oligotyping) were tested in a group of 50 consecutive patients with PsA, 32 with skin psoriasis (PSO), and 255 healthy persons. Data on age, gender, disease duration, and pattern of rheumatological manifestations-oligoarthritis, polyarthritis, spinal involvement, involvement of distal interphalangeal joints (DIPs), and enthesitis-were registered. Results. Human leukocyte antigens A3, B13, and B38 alleles were found to be significantly prevalent in PsA compared with PSO patients and healthy controls. HLA-B27 was found in only two out of 50 patients with PsA. Patients with PSO and PsA had significantly increased incidence of HLA-DRB0101 and -DRB0301, while the frequency of HLA-DRB0403 was significantly higher among patients with PsA of Ashkenazi origin. We found a statistically significant association between DIP involvement and the presence of HLA-A26 and -B38, while HLA-DRB0301 was related to spinal involvement. Conclusions. Psoriatic arthritis in Israeli patients seems to be associated with the presence of HLA-A3, -B13, -B38, -DRB0101, and -DRB0301. HLA-B27 was not a marker of PsA in this cohort of patients, including patients with psoriatic spondyloarthropathy.