HLA antigens in psoriatic arthritis and psoriasis

In this study we report on the incidence of the HLA antigens of the histocompatibility system in patients with psoriatic arthritis and psoriasis. We separated from each group an additional subgroup, as follows: (1) a subgroup of patients with psoriasis in whose families the disease occurred (familial psoriasis) and (2) a subgroup of patients who had psoriatic arthritis with affection of the sacroiliac joints and the spine (psoriatic spondylitis). Patients and Methods The investigation comprised 60 patients (45 men and 15 women) with symptoms of psoriatic arthritis and 65 patients (36 men and 29 women) with psoriasis. In the first group, the sacroiliac joints and the spine were affected in 19 patients (psoriatic spondylitis) and in the second group, 19 patients came from families in which at least one other member suffered from psoriasis (familial psoriasis). The control group consisted of 302 unrelated persons who showed neither psoriatic arthritis nor