Lucus B HLA antigens in psoriatic patients. Population and family studies and clinical relationship.

The HLA gene and haplotype frequencies in psoriatic population (N = 136) and families (N = 47) were estimated. The significant association with HLA-B17 and B13 was found. The relative risk for these antigens was 4.4 and 2.4, respectively. The most frequent haplotypes carrying the "psoriatic" antigens was HLA-A1, B17 and HLA-A10, B17, with significant relative risk, equalled 8.24 and 5.75. The distribution of HLA-B13 and B17 phenotypes according to the three groups of clinical activity and four groups of extent of skin lesions were considered. The strong association between HLA-B17 and psoriasis with large skin involvement (more than 50%) was observed. The possible role of antigen B17 in pathomechanism of psoriasis is discussed.