INFLAMMATORY BOWEL-DISEASE - NO ASSOCIATION BETWEEN ALLELE COMBINATIONS OF THE INTERLEUKIN (IL) 1-BETA AND IL-1 RECEPTOR ANTAGONIST GENE POLYMORPHISMS

Background Interleukin I (IL-1) and its physiological antagonist inter leukin-l receptor antagonist (IL-1ra) play a crucial role in the patho genesis of inflammatory bowel disease. Polymorphisms in the genes codi ng for these cytokines, the restriction enzyme TaqI polymorphism for I L-1 beta and the variable number of tandem repeats (VNTR) polymorphism for IL-1ra, have been shown to influence cytokine synthesis in vitro. Recently, an association has been described for distinct allele combi nations of these two polymorphisms in patients with ulcerative colitis and with Crohn's disease but not in healthy control subjects. Methods We studied 56 patients with ulcerative colitis, 64 patients with Croh n's disease and 196 healthy control subjects. All were unrelated Cauca sians of European ancestry. After polymerase chain reaction (PCR) the amplification products were analysed on agarose gels. For the IL-1 bet a polymorphism the PCR product was additionally digested using the res triction enzyme TaqI. Results The allele and genotype frequencies as w ell as the carriage rates of the IL-1 beta TaqI polymorphism in health y control subjects were in agreement with previous, findings in other populations. Allele and genotype frequencies of the IL-1 beta polymorp hism were not different in inflammatory bowel disease patients compare d with healthy control subjects. Comparing allele combinations of both polymorphisms no association could be identified either within health y control subjects or in the groups of patients with ulcerative coliti s or Crohn's disease. Conclusion Thus, we could not confirm the result s of a previous study reporting an association between the IL-1ra and IL-1 beta gene polymorphisms in patients with inflammatory bowel disea se.