Patent ID: 7183065

Claim:
A method of diagnosing ulcerative colitis (UC) in a human subject suspected of having inflammatory bowel disease, comprising: (a) obtaining a sample from said subject; (b) contacting said sample with an isolated pANCA-reactive Bacteroides protein antigen of about 100 kDa, or pANCA-reactive polypeptide portion thereof, under conditions suitable to form a complex of said Bacteroides protein antigen, or said pANCA-reactive polypeptide portion thereof, and pANCA antibody to said Bacteroides protein antigen; wherein said pANCA antibody is capable of reacting with human histone H1, wherein said Bacteroides is an enteric Bacteroides species, and (c) detecting the presence or absence of said complex, wherein the presence of said complex indicates that said subject has UC.