Objective: The pathogenesis of sinonasal polyposis (SNP) is not clear; it has been suggested that it is polygenic and multifactorial. The major histocompatibility complex is a useful tool to predict genetic susceptibility to diseases, especially to autoimmune diseases. Since such susceptibility is influenced by ethnicity, it is necessary to have a wide knowledge of the structure of the population to which the patient belongs. The purpose of the study was to determine the association of HLA-DRB1 alleles with sinonasal polyposis in the Mexican Mestizo population.
Study design: We studied the HLA-DR alleles in 34 adult Mexican Mestizo patients with SNP and compared them to those present in 99 healthy controls.
Methods: Genomic DNA from mononuclear cells was obtained by using the "salting out" technique and high-resolution DNA typing of the HLA-DRB1 alleles was performed after PCR amplification.
Results: We found a statistically significant increased frequency of the HLA-DRB1*03 allele (P = 0.03, odds ratio [OR] = 2.9, 95% confidence interval [CI]: 1.0-7.8) and of the HLA-DRB1*04 allele (P = 0.009, OR = 2.2, 95% CI: 1.2-4.2) in patients with SNP as compared to controls, and a statistically significant decreased frequency of the HLA-DRB1*08 allele (P = 0.01, OR = 0.2, 95% CI: 0.05-0.8).
Conclusion: The HLA-DR locus seems to be associated with the genetic susceptibility to develop SNP in Mexicans.
Ebm rating: B-2b.