Association of Polymorphisms in the HumanIL4andIL5Genes with Atopic Bronchial Asthma and Severity of the Disease
Two polymorphisms in theIL4(G/C 3′-UTR) andIL5(C-703T) genes were studied in a sample of families whose probands had atopic bronchial asthma (BA) (66 families, n = 183) and in a group of non-cognate individuals with the severe form of the disease (n = 34). The samples were collected from the Russian population in the city of Tomsk (Russia). Using the transmission/disequilibrium test (TDT), a significant association of allele C-703IL5with BA was established (TDT = 4.923,p= 0.007 ± 0.0007). The analysis of 40 individuals with mild asthma and 49 patients with the severe form of the disease revealed a negative association of genotype GGIL4(OR = 0.39, 95% CI = 0.15−0.99,p= 0.035), and also a trend towards a positive association of the GCIL4genotype (OR = 2.52, 95% CI = 0.98−6.57,p= 0.052) with mild BA. There was a concordance of the clinical classification of BA severity with the ‘genotype’ (McNemar'sχ2test with continuity correction constituted 0.03, d.f. = 1,p= 0.859). These results suggest that polymorphisms in theIL4andIL5genes contribute to the susceptibility to atopic BA and could determine the clinical course of the disease.