Objective: The aim of this study was to determine the contribution of the human major histocompatibility complex (HLA)-DQA1, -DQB1, and TNFalpha genes with simple nasal polyposis.
Study design and setting: A comparative case-control study with 31 patients and 151 controls was performed. HLA-DQA1, -DQB1, and TNFalpha -238 promoter position loci were typed by polymerase chain reaction (PCR) and sequence specific oligonucleotide probes (SSOPs). TNFalpha -308 promoter position was determined by PCR and digestion with NcoI restriction enzyme.
Results: The allele HLA-DQA1*0201 (P(c) = 0.019) had an etiologic fraction (EF) of 17%, whereas 13% EF was found for the haplotype HLA-DQA1*0201-DQB1*0201 (P = 0.016). Analysis of -DQB1 and TNFalpha promoter did not show significant differences between cases and controls.
Conclusions: HLA-DQA1*0201-DQB1*0201 haplotype is involved in susceptibility, conferring 5.53 times more risk of developing this disease.
Ebm rating: B-2b.