ANALYSIS OF TAP2 AND HLA-DP GENE POLYMORPHISM IN PSORIASIS

TAP2 is a gene, located between HLA-DP and HLA-DQ, whose products form a transporter molecule involved in endogenous antigen processing. Pol ymorphic residues have been described in this gene. TAP2 is of particu lar interest because its involvement in antigen presentation makes it a candidate for a disease susceptibility gene. In psoriasis, two clini cal subtypes analogous to the situation in diabetes type I with early onset and family history and type II with later onset and without fami ly history have been described. We have previously shown that type I b ut not type II psoriasis is associated with the HLA-DRB10701/2, -DQA1 0201, -DQB1*0303 haplotype. To investigate whether this haplotype ext ends to include particular TAP2 and/or DP alleles, we tested the TAP2 and HLA-DP alleles of a control group (n = 133), patients with psorias is type I (n = 66), and patients with psoriasis type II(n = 35) by hyb ridization with SSOs. Out data show that there is no significant corre lation between TAP2 and/or HLA-DP gene polymorphism and psoriasis type I and/or type II. We conclude that disease association in type I psor iasis is associated with the extended haplotype HLA-B57, -Cw6, -DRB10 701/2, -DQA10201, -DQB1*0303.