Patent ID: 8043832

Claim:
A method for the differential diagnosis of Crohn's disease or ulcerative colitis in patients having inflammatory bowel disease comprising, 1) isolating immunoglobulin G from the serum of a patient with Crohn's disease or ulcerative colitis, 2) releasing oligosaccharides from the immunoglobulin G, 3) determining the ratios of G0 oligosaccharide represented by formula (I): to G2 oligosaccharide represented by formula (II): to obtain G0/G2 ratios in the serum of the patient having Crohn's disease or ulcerative colitis and in the sera of healthy individuals, wherein G represents galactose, M represents mannose, GN represents N-acetylglucosamine and F represents fucose in serum IgG oligosaccharide fraction, and 4) generating a relative ratio by comparing G0/G2 ratio in the serum of the patient having Crohn's disease or ulcerative colitis with G0/G2 ratios in the sera of healthy individuals, 5) comparing the relative ratio of step 4) to a predetermined value, wherein the predetermined value is obtained by comparing G0/G2 ratio in the sera of patients having Crohn's disease or ulcerative colitis with G0/G2 ratios in the sera of healthy individuals, and 6) differentially diagnosing the patient as having Crohn's disease when the ratio of G0/G2 is higher than the predetermined value, and the patient is diagnosed as having ulcerative colitis when the ratio of G0/G2 is lower than the predetermined value.