Methods: A total of 109 patients with asthma were divided into two groups, allergic and non-allergic asthma, according to clinical history, skin prick test and serum-specific IgE measurement. The control group had 297 deceased donors of solid organs. Patients and controls had their HLA class I and II genotyped and were compared.
Results: Non-allergic patients were older at the onset of asthma and had higher rate of intolerance to non-steroidal anti-inflammatory drugs. Allergic patients had higher total serum IgE, reported atopic dermatitis and conjunctivitis more frequently, and unexpectedly, had greater disease severity. New associations between HLA genotypes and allergic and non-allergic asthma were identified. HLA-B*42, HLA-C*17, HLA-DPA1*03 and HLA-DPB1*105 genotypes were associated with allergic asthma and HLA-B*48 genotype with the non-allergic phenotype. The presence of the haplotype HLA-DPA1*03 DQA*05 was associated with allergic asthma, and the presence of HLA-DPA1*03 and absence of HLA-DQA*05 with non-allergic asthma.
Conclusions: The study identified new associations of HLA class I and II with allergic and non-allergic asthma in Brazilian population, which is characterized by diversity of origins and miscegenation.