LACK OF ASSOCIATION BETWEEN AN INTERLEUKIN-1 RECEPTOR ANTAGONIST GENEPOLYMORPHISM AND ULCERATIVE-COLITIS

Background-Recently, the association of a polymorphism in the gene cod ing for the anti-inflammatory cytokine interleukin-l receptor antagoni st with ulcerative colitis has been reported. This was interpreted as a possible genetic predisposition for severity of the inflammatory res ponse. Aims-To examine this polymorphism in a southern German populati on. Subjects-The study included 234 healthy controls, 57 patients with ulcerative colitis, including 31 patients with pancolitis, 44 first d egree healthy relatives of patients with ulcerative colitis, and 65 pa tients with Crohn's disease. Methods-Genotypes were determined by a po lymerase chain reaction amplification of the intron 2 fragment harbour ing a variable number of tandem repeat nucleotide sequences. Amplifica tion products were separated on a 2% agarose gel. Results-The allele f requency for allele 2 was 27% in healthy controls, 28% in Crohn's dise ase, and 21% in patients with ulcerative colitis. The same allele freq uency (21%) was found in a subgroup of patients with ulcerative coliti s affecting the whole colon. Thus for allele 2 as well as for all othe r alleles, genotypes, or carriage rates no significant differences wer e found compared with controls. All allele frequencies in the control population were similar to those in earlier studies. Conclusions-No as sociation of a polymorphism in the interleukin-l receptor antagonist g ene with ulcerative colitis could be identified in this southern Germa n population. The findings of an earlier study reporting an increased frequency of allele 2, particularly in patients with pancolitis, could not be confirmed.