Objective: To study whether the Chinese ulcerative colitis (UC) patients are associated with interleukin (IL)-1beta, IL-1RA and IL-4 gene polymorphisms and to analyze the relationship among gene polymorphisms, antineutrophil cytoplasmic antibodies (ANCA) and clinical classification of UC.
Methods: eighty-one UC patients and 114 healthy subjects (HS) were enrolled. IL-1beta, IL-1RA, and IL-4 gene polymorphisms were analyzed with polymerase chain reaction-restriction fragment length polymorphism and polymerase chain reaction with sequence-specific primers respectively.
Results: The gene frequency of allele RP2 of IL-4 in UC patients was significantly higher than that in HS (29.0% vs 11.8%, P = 0.00002), but the gene frequency of allele RP1 in HS was significantly higher than that in UC patients (88.2% vs 71.0%, P = 0.00002). OR of the genotype RP1.2 and RP2.2 were 2.71 (95% CI 1.39 approximately 5.31) and 9.04 (95% CI 1.05 approximately 203.29) respectively. There was not difference in the gene frequencies of IL-1beta, IL-1RA between UC patients and HS (P > 0.05). When UC patients were divided into ANCA positive and negative groups, it was found that there was significant difference in the gene frequencies of allele RP1, RP2 of IL-4 between two groups (63.7% vs 83.3%, 36.3% vs 16.7%, P < 0.05).
Conclusions: There is correlation between the Chinese UC patients and the gene polymorphisms of intron 3 of IL-4. The gene frequency of allele RP1 in UC patients are lower, but the gene frequency of allele RP2 is significantly higher. The differences on gene frequencies of IL-4 between the UC patients and HS are mainly found in the ANCA positive UC patients. The Chinese UC patients are not associated with IL-1beta and IL-1RA gene polymorphisms.