title: Allergic and Nonallergic Asthma Have Distinct Phenotypic and Genotypic Features.
abstract: BACKGROUND
  Identification of asthma phenotypes enables a better understanding and management of this heterogeneous disease. Studies have reported associations between human leukocyte antigens (HLA) and asthma in different populations, but the results have been inconclusive and they have rarely considered the distinct disease phenotypes. Our objective was to characterize allergic and nonallergic asthma phenotypes and evaluate possible associations with the HLA system.
  
  
  METHODS
  A total of 109 patients with asthma were prospectively followed during 2 years. They were divided into 2 groups, i.e., allergic and nonallergic asthma, according to their clinical history and skin prick test and serum-specific immunoglobulin E (IgE) results. The control group comprised 297 deceased donors of solid organs. Patients' features and HLA class I and II genotypes were assessed and compared.
  
  
  RESULTS
  This study showed different features between asthma phenotypes. Nonallergic patients were older at the onset of asthma symptoms and had a higher rate of intolerance to nonsteroidal anti-inflammatory drugs. Allergic patients had higher total serum IgE levels, reported atopic dermatitis and rhinoconjunctivitis more frequently, and, unexpectedly, had a greater disease severity. New associations between the HLA genotypes and allergic and nonallergic asthma were identified. The HLA-B*42, HLA-C*17, HLA-DPA1*03, and HLA-DPB1*105 genotypes were associated with allergic asthma and the HLA-B*48 genotype with the nonallergic phenotype. The presence of the haplotype HLA-DPA1*03 DQA*05 was associated with allergic asthma, and the presence of HLA-DPA1*03 and the absence of HLA-DQA*05 with nonallergic asthma.
  
  
  CONCLUSIONS
  Allergic and nonallergic asthma have distinct phenotypic and genotypic features. New associations between asthma phenotypes and HLA class I and II were identified.
authors.affiliation: Clinical Immunology and Allergy Division, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Priscila
authors.initials: P
authors.lastname: Takejima
authors.forename: Rosana Câmara
authors.initials: RC
authors.lastname: Agondi
authors.forename: Helcio
authors.initials: H
authors.lastname: Rodrigues
authors.forename: Marcelo Vivolo
authors.initials: MV
authors.lastname: Aun
authors.forename: Jorge
authors.initials: J
authors.lastname: Kalil
authors.forename: Pedro
authors.initials: P
authors.lastname: Giavina-Bianchi
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects; D001249:Asthma / Q000097:blood / Q000235:genetics* / Q000276:immunology; D001938:Brazil; D015331:Cohort Studies; D005260:Female; D005838:Genotype; D006680:HLA Antigens / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008297:Male; D008875:Middle Aged; D010641:Phenotype
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D006680:HLA Antigens; D007073:Immunoglobulin E
keywords: Allergic asthma; Asthma; Human leukocyte antigens; Nonatopic