Polymorphisms and haplotype analysis of IL-4Ralpha Q576R and I75V in patients with penicillin allergy.

BACKGROUND: The interleukin (IL)-4 and IL-4R genes are linked to allergic diseases and atopy and elevated serum IgE levels closely follow the presentation of penicillin allergy. We have evaluated the association between specific immunoglobulin (Ig)E, polymorphisms of IL-4Ralpha, and penicillin allergy. METHODS: Eight types of specific IgE to penicillins were detected with the radioallergosorbent test (RAST) in 242 patients with penicillin allergy and 220 control subjects. Polymorphisms of IL-4Ralpha Q576R and IL-4Ralpha I75V were genotyped by PCR-restriction fragment length polymorphism (RFLP). The polymorphisms and haplotype of IL-4Ralpha Q576R and I75V were analyzed. RESULTS: For IL-4Ralpha Q576R, the frequency of the AA genotype was higher in patients with penicillin allergy (76 vs. 64%, P = 0.005). The A allele occurred more frequently in the penicillin-allergic patients than in the controls (87 vs. 80%, P = 0.003). For IL-4Ralpha I75V, the AA genotype was more likely to be detected in the urticaria group than in the control group (32 vs. 19%, P = 0.049). Haplotype analysis revealed that Q576/I75 was more frequently found in patients with penicillin allergy than in controls (42 vs. 35%, P = 0.037). CONCLUSIONS: The IL4Ralpha Q576 allele is related to penicillin allergy, and the IL-4Ralpha I75 allele is associated with the symptom of urticaria. The Q576/I75 haplotype may be related with an allergy to penicillin.