Association between Arg753Gln (rs574308) polymorphism of the Toll-like receptor 2 (TLR2) gene and the risk of pulmonary sarcoidosis among the residents of Karelia”

Abstract

Genetic factors play an important role in the development and progression of many disorders including lung sarcoidosis which is a systemic inflammatory granulomatous disease of unknown etiology, characterized by the formation of epithelioid cell granules in affected tissues. Intensity of the developing inflammation may partially depend on genetic factors which may influence both susceptibility to lung sarcoidosis, and also clinical course of the disease and the degree of inflammatory response from the immune system. Allelic polymorphism of distinct genes is therefore worth of study. In the carriers of certain allele variants, one may observe either increase, or a decreased production of pro-inflammatory factors. Among the candidate factors involved in higher susceptibility of humans, one may consider Toll-like receptors (TLRS) which may contribute to formation of granulomas. Relevant data concerning association between the allele variants of these genes and susceptibility to lung sarcoidosis, and its clinical course are still quite limited and contradictory. The aim of the present study was to analyze the association between the Arg753Gln (rs574308) polymorphism of the Toll-like receptor 2 (TLR2) gene and the risk of developing pulmonary sarcoidosis.A total of 253 persons were under study including 122 patients diagnosed with morphologically verified sarcoidosis with lung involvement (average age, 41.00±12.56 years), and 131 healthy donors comprising a control group (average age, 44.00±14.23 years). The distribution of alleles and genotypes for the Arg753Gln (rs574308) polymorphic TLR2 gene marker was studied in the groups of patients with pulmonary sarcoidosis and healthy donors. The test alleles of this polymorphic marker were typed by means of PCR technique followed by length analysis restriction fragments (PCR-RFLP method).There were no statistically significant differences in the distribution of allele and genotype frequencies for the polymorphic marker Arg753Gln (rs574308) of the TLR2 gene between the control group and the group of patients with pulmonary sarcoidosis: χ2 = 2.0, df = 1, p = 0.158 and χ2 = 2.19, df = 2, p = 0.140, respectively.The polymorphic marker Arg753Gln (rs574308) of Toll-like receptor 2 gene is not associated with the risk of developing pulmonary sarcoidosis among ethnic Russians of the Republic of Karelia.