HLA antigens in psoriasis.

In the group (N = 136) of psoriatic patients 27 HLA antigens determined by A and B loci were identified. Phenotype, gene and haplotype frequencies were calculated and compared with the control data. A significant association between psoriasis and HLA-B13 and/or HLA-B17 was confirmed. The relative risk for these antigens amounted to 2.3 and 4.4 respectively. Among all haplotypes calculated for the psoriatic population there were only six with significant relative risk ranging from 3.1 to 27.4. Unexpectedly, the highest relative risk (27.4) was found for haplotype HLA-A9, X.