Background. Chronic urticaria is a common disease with an unclear pathogenesis, which may be resistant to therapy. Recent studies have focused primarily on a possible autoimmune basis.
Aim. To investigate HLA class I and II antigens in a Turkish population with chronic ordinary urticaria (COU; not physical, vasculitic or contact), and identify susceptible HLA antigens.
Methods. HLA antigens were investigated in 55 patients diagnosed with COU, using a two-stage microdroplet lymphocytotoxicity test, with 104 healthy and genetically unrelated individuals evaluated as the control group.
Results. HLA Bw4 and HLA DQ1 antigens were significantly higher in the study group (odds ratio (OR) = 2.93, 95% CI 1.47–5.85, P = 0.003 and OR = 7.81, 95% CI 1.96–28.50, P = 0.001, respectively) whereas HLA-A24 antigen was higher in controls (OR = 0.36, 95% CI 0.15–0.86, P = 0.03).
Conclusion. We propose that HLA-Bw4 and DQ1 antigens may be responsible for susceptibility to COU while HLA-A24 may have a protective role in the Turkish population.