Genotyping of human killer cell immunoglobulin-like receptor genes in Japanese patients with psoriatic arthritis, generalized pustular psoriasis or psoriasis vulgaris

The interaction of HLA-C with killer immunoglobulin-like receptors (KIRs) on natural killer cells and some natural killer-T cells together with a strong association between HLA (human leukocyte antigen), especially HLA-Cw*06, and psoriasis indicates that this is an immune-mediated disorder. The association between KIRs and psoriatic arthritis (PA) and generalized pustular psoriasis (GPP) was investigated by typing 14 KIR genes from Japanese patients with GPP, PA or psoriasis vulgaris (PV) using PCR. Frequencies of KIR2DS1 and KIR2DL5, which was in linkage disequilibrium with KIR2DS1, were significantly increased in PV cases when compared with controls. We report an increase in KIR2DS1 and KIR2DL5 in Japanese patients with GPP and PV. The KIR haplotype (KIR2DS1+2DS2+2DS3) in PA cases occurred more frequently than in GPP and PV cases. Thus, KIR2DS1 may be a common factor in susceptibility to psoriasis, although the variation in the frequencies of HLA-C and KIRs in cases of PV, GPP, and PA indicates that other genetic factors are also involved.

susceptibility to psoriasis

human leukocyte antigen

natural killer cells

killer cell immunoglobulin-like receptors