Disparate distribution of activating and inhibitory killer cell immunoglobulin-like receptor genes in patients with systemic lupus erythematosus.

The genes of killer cell immunoglobulin-like receptors (KIRs), which are involved in the activation of T cells and natural killer cells, are highly variable. In recent years, the role of KIRs in autoimmune diseases has received increasing attention. The present study was undertaken to determine the association of the polymorphism of KIR genes with the susceptibility to systemic lupus erythematosus (SLE). The polymorphism of KIR genes of 93 patients with SLE together with 123 healthy donors as the control group was determined by polymerase chain reaction with sequence-specific primers. Twenty-seven novel gene combinations were found. Genotypic frequencies of KIR2DL2 (p < 0.001) and KIR2DS1 (p < 0.001) were much higher in patients with SLE than in control subjects. Individuals with two and more than two activating KIR genes were found more frequently in patients than in control subjects (80.7% versus 66.7%, p = 0.022). The results suggest that a genetic disturbance between activating and inhibitory KIR genes may be one of the key factors underlying the pathogenesis of SLE.