Abstract: A novel, differential association between allele 2 of the variable number of tandem repeats polymorphism at intron 2 of the human IL-1 receptor antagonist gene and ulcerative colitis in humans of Jewish ancestry has been discovered. In accordance with the present invention, there is provided methods of screening for ulcerative colitis in human subjects of Jewish ancestry comprising detecting the presence or absence of nucleic acid of the subject encoding allele 2 of the variable number of tandem repeats polymorphism at intron 2 of the human IL-1 receptor antagonist gene, wherein the presence of nucleic acid encoding allele 2 is indicative of ulcerative colitis. Kits useful for screening for ulcerative colitis in human subjects of Jewish ancestry are also provided.

Abstract: The present invention provides a method of diagnosing a clinical subtype of Crohn's disease (CD) by determining whether perinuclear anti-neutrophil antibodies (pANCA) are present in a patient with CD, where the presence of pANCA indicates the clinical subtype of CD with features of ulcerative colitis (UC). The invention also provides a method of diagnosing a clinical subtype of CD by detecting an Arg.sup.241 allele at an ICAM-1 locus in a patient with CD, where the Arg.sup.241 allele indicates a clinical subtype of CD with features of ulcerative colitis. In addition, the invention provides a method of diagnosing a pANCA-positive subtype of CD by detecting an Arg.sup.241 allele at an ICAM-1 locus in a patient with CD, where the Arg.sup.241 allele indicates the pANCA-positive subtype of CD.

Abstract: A novel association between IBD and a polymorphism at amino acid residue 241 of ICAM-1 has been discovered. In accordance with the present invention there is provided methods of screening for IBD, methods for treating IBD, antibodies specifically reactive wish ICAM-1 encoded by R241 allele and kits which exploit the inventive methods.