Association of killer cell immunoglobulin-like receptor genotypes with vascular arterial events and anticardiolipin antibodies in patients with lupus.

To determine whether killer cell immunologlobulin-like receptor (KIR) genotypes are associated with vasculitis, vascular arterial events or anticardiolipin (aCL) antibodies in patients with lupus. A total of 304 patients followed prospectively at the University of Toronto Lupus Clinic were assessed for the occurrence of vasculitis and vascular arterial events. Molecular HLA-C and KIR (presence or absence of KIR2DL1, 2DL2, 2DL3, 2DS1 and 2DS2) genotyping were performed. Chi-square and logistic regression were used to analyse association between KIR genes and vascular arterial events and aCL antibodies. In patients with vascular arterial events, there was a significant increase in KIR2DS2 (60% vs 45%, P = 0.02) and in KIR2DL2 (62% vs 47%, P = 0.01) compared with patients without events. There was no increase in activating KIR genotypes in patients with vasculitis. In patients with aCL antibodies, significant increases were seen in KIR2DS2 (54% vs 41%, P = 0.03) and KIR2DL2 (58% vs 41%, P = 0.003), but KIR2DL3 was decreased (87% vs 95%, P = 0.03). Logistic regression confirmed independent association of KIR2DS2 with vascular arterial events. We found an increase in KIR2DS2 in lupus patients with vascular arterial events, but not in patients with vasculitis.