Nasal polyposis is a disease characterized with chronic inflammation of the nasal mucosa. Toll-like receptors (TLRs) are defined as essential receptors of the innate immune system and may play in the development of nasal polyposis. A total of 71 patients with nasal polyposis and 74 healthy controls were included in this study. Three single-nucleotide polymorphisms (SNPs); TLR2 (2258 A>G), TLR4 (896 A>G), and TLR4 (1196 C>T) were analyzed in all patients. The degree of pair-wise linkage disequilibrium and the genotype and haplotype analyses were conducted using regression in this logistic model and the Multifactor Dimensionality Reduction (MDR) software package was used to construct all possible interactions among different genotype variants belonging to the TLR gene. There was significant difference in genotype and allele frequencies of the TLR4 (1196 C>T) polymorphism between the nasal polyposis and control groups (0.017). Also, it was observed that the probability of nasal polyposis was 62.7% in the presence of TLR4 (1196 C>T) polymorphism with asthma (P = .007). As a conclusion, this study showed that TLR4 and TLR2 polymorphisms were predisposing factors for nasal polyposis. Further functional studies investigating the consequences of loss of TLR function are needed.
Keywords: Toll-like receptor; nasal mucosa; nasal polyposis; single-nucleotide polymorphism.