Analysis of class I HLA molecule phenotypes in patients with hypersensitivity reactions to non-steroidal antiinflammatory drugs

Abstract

Background: The association studies of various alleles of the major histocompatibility complex to hypersensitivity adverse reactions to non- steroidal antiinflammatory drugs (NSAIDs) have yielded discordant results. Aims: to analyze the phenotypes of Class I HLA molecules in patients with hypersensitivity adverse reactions to (NSAIDs). Patients and Methods: A group of 90 patients with hypersensitivity adverse reactions to NSAIDs and another one of 144 control patients who were NSAID-tolerant (83 atopic and 61 non- atopic patients) were selected through controlled oral NSAID challenge. HLA- A, -B and -Cw anigen typing was performed through a standard microlymphotoxicity test. Results: There were no significant differences between the adverse reaction and the control patient populations as regards the distribution of phenotypes of HLA-A and -B molecules. The HLA-Cw7 penotype was significantly overrepresented (p<0.01) in the patients with NSAID-induced anaphylactoid reactions. The frequencies of the HLA-Cw phenotypes in patients with isolated periorbital angioedema were not significantly different from those in the control group. Conclusions: HLA- Cw7 is a genetic marker which is specifically associated to the population with NSAID-induced anaphylactoid reactions. The clinical and genetic heterogeneity of the various types of reactions probably expresses the existence of diverse pathogenetic mechanisms in these forms of hypersensitivity adverse reactions.