The aim of the study is to examine the role of HLA and killer immunoglobulin-like receptors (KIR) in the natural history of psoriasis vulgaris. Psoriasis is a chronic inflammatory disease of the skin with features of an autoimmune disease, and previous studies have revealed an association with certain HLA class I alleles, notably HLA-Cw\*0602. Natural Killer (NK) cells are a unique group of lymphocytes involved in surveillance of killing of foreign or infected cells through a mechanism involving recognition of HLA class I molecules by an extremely diverse set of receptors on the NK cell surface. A major group of these receptors are the KIRs. Thus, a relationship between KIR/HLA genotype and psoriasis is biologically plausible, and indeed previous data from our laboratory have shown a strong association with the activating genes KIR2DS1 and KIR2DS2 and development of psoriatic arthritis, a well-recognized complication of psoriasis.
Dr. James Elder and colleagues at the University of Michigan have identified a cohort of more than 560 families through the dermatology services of the University of Michigan Medical Center, the University of Kiel, Henry Ford Hospital, and the National Psoriasis Foundation Tissue Bank. Individuals have been well characterized clinically, and information on race, ethnicity, age at onset, current age, and history of inflammatory bowel disease and/or other autoimmune disorders has been obtained. The large size of the cohort will provide substantial statistical power, which is of major importance in any KIR/HLA association study.
