Serologic markers in inflammatory bowel disease: state of the art.

A variety of serologic tests are emerging that are relevant to the diagnosis and treatment of Crohn's disease and ulcerative colitis. These laboratory tests include: anti-neutrophil cytoplasmic antibody with perinuclear staining (pANCA); anti-Saccharomyces cerevisiae antibody (ASCA); outer membrane porin C (Omp C); and I2 antibody (novel homologue of the bacterial transcription-factor families). The potential roles for serologic testing for inflammatory bowel disease (IBD) include adjunctive diagnostic testing in patients with known IBD, screening testing for IBD in patients with compatible gastrointestinal symptoms, and serving as a marker of unique disease course or prediction of response to specific treatments. This article reviews the use of pANCA, ASCA, I2, and Omp C in patients with IBD.