Assessment and relevance of enzyme-linked immunosorbent assay for antibodies to Saccharomyces cerevisiae in Australian patients with inflammatory bowel disease.

The frequency of antibodies to Saccharomyces cerevisiae (ASCA) in Crohn's disease, ulcerative colitis and non-inflammatory bowel disease controls has been compared using two commercially available assays. The Medizym test resulted in sensitivity of 50% and specificity of 93% for Crohn's disease. The corresponding figures for the QUANTA Lite assay were 79% and 74%, respectively. Using ASCA and perinuclear antineutrophil cytoplasmic antibody (pANCA) in combination, the sensitivity and specificity of ASCA+/pANCA- for Crohn's disease using the Medizym kit were 50% and 100%, respectively, compared with 79% and 93% using QUANTA Lite. ASCA-/pANCA+ was 100% specific for ulcerative colitis with either assay. ASCA can be found in Australian patients with Crohn's disease at a similar frequency to that reported overseas.