ASPIRIN-INDUCED ASTHMA AND HLA-DRB1 AND HLA-DPB1 GENOTYPES

Background Aspirin-induced asthma (AIA) affects one in 10 individuals with adult-onset asthma. It is not known if aspirin sensitivity is due to immune mechanisms or to interference with biochemical pathways. Ob jective The study aimed to test for possible involvement of the genes of the Major Histocompatibility Complex (MHC) in AIA. Methods HLA-DPB1 and HLA-DRB1 genotyping was carried out by DNA methods in 59 patients with positive challenge tests for AIA and in 48 normal and 57 asthmat ic controls. Results The DPB10301 frequency was increased in AIA pati ents when compared with normal controls (19.5% vs 5.2%, Odds Ratio=4.4 , 95% Confidence Interval (CI) 1.6-12.1, P=0.002), and compared with a sthmatic controls (4.4%, OR=5.3, 95%CI=1.9-14.4, P=0.0001). The freque ncy of DPB10401 in AIA subjects was decreased when compared with norm al controls (28.8% vs 49.0%, OR=0.42, 95%CI=0.24-0.74, P=0.003) and as thmatic controls (45.6%, OR=0.48, 95%CI=0.28-0.83, P=0.008). The resul ts remained significant when corrected for multiple comparisons. There were no significant HLA-DRB1 associations with AIA. Conclusion The pr esence of an HLA association suggests that immune recognition of an un known antigen may be part of the aetiology of ALA.