Prometheus Laboratories Inc. announced new findings regarding a correlation between an important serologic marker used in the detection of Crohn’s disease and particular genetic markers in patients at risk for celiac disease. In an oral presentation on June 1, 2009 at Digestive Disease Week (DDW) in Chicago, Prometheus reported a statistically significant correlation between antibodies to the flagellin CBir1 and HLA haplotypes DQ2.5 and DQ8 in a study of 5,406 patients at risk for celiac disease who are EMA positive. Blood and serum samples were analyzed using PROMETHEUS Celiac PLUS and PROMETHEUS IBD Serology 7 diagnostic tests.
“Genetic tests to rule out celiac disease are now readily available. However, few genetically predisposed individuals actually develop the disease, despite gluten ingestion, for reasons that are not well understood,” said Dr. Michelle Pietzak, a Pediatric Gastroenterologist in the Division of Gastroenterology at the University of Southern California Keck School of Medicine. “The results from this study show that an overly aggressive immune response to particular bacteria in the intestine, as in Crohn’s disease, may contribute to the inflammation seen in patients with celiac disease.”
Results from two additional studies regarding the prediction of inflammatory bowel disease (IBD) using serology testing were also presented on June 1, 2009 at DDW. The first examined the consistency of biomarkers in patients who received multiple PROMETHEUS IBD Serology 7 tests within a two-year period. The overall rate of repeat testing ordered was only 2.2%. The results showed high concordance between the original and repeat tests; median changes in biomarker serum concentrations ranged between 2.2 EU/mL and 4.3 EU/mL. These results are consistent with reports in the scientific literature suggesting biomarker stability over similar time periods. Further studies are required to evaluate the impact of therapy on biomarker stability over longer periods of time.
The clinical utility of PROMETHEUS IBD Serology 7 was further demonstrated in a separate, multi-center clinical study of an additional 1,574 patient samples, increasing the total development cohort of the test to a more heterogeneous 3,626 patient samples. Results with this large patient cohort further confirmed that using multiple markers combined with Prometheus’ Smart Diagnostic Algorithm is more effective at differentiating IBD vs. non-IBD and Crohn’s disease vs. ulcerative colitis than using traditional cutoff value analysis of the individual markers alone. PROMETHEUS IBD Serology 7 combines multiple serologic markers with a proprietary Smart Diagnostic Algorithm, which increases the sensitivity of the test by more than 25% when compared to single marker sensitivity values.