In view of the high diagnostic accuracy of immunoglobulin-A-tissue transglutaminase antibodies for detecting coeliac [celiac] disease, we have explored whether a small bowel biopsy is always required to establish the diagnosis.
Aim: To define the transglutaminase antibody level giving a positive predictive value for coeliac disease of 100% and to subsequently assess the proportion of new diagnoses of coeliac disease having such a result.
Methods: The Celikey kit (Phadia GmbH, Frieburg, Germany) was used to measure transglutaminase antibody levels.
Results: All patients with transglutaminase antibody levels >30 U/mL, i.e. 10 × upper limit of normal in 2002/2003 had characteristic small bowel mucosal lesions. In a subsequent audit, 58% of 112 new diagnoses of coeliac disease in 2004/2005 had levels above this cut-off value.
- We have shown that a transglutaminase antibody level can be defined which gives a positive predictive value of 100% for coeliac disease. From published data, these observations can be extended to most second-generation transglutaminase antibody kits.
- Our data provide further evidence that diagnostic guidelines could be modified so that small bowel biopsy is no longer regarded as mandatory in patients with such high transglutaminase antibody levels.
- This will avoid an invasive procedure and lead to a more rapid diagnosis and earlier treatment for over half of the new patients with coeliac disease.
Source: Alimentary Pharmacology & Therapeutics, April 2008. 27 (7), 572–577. DOI:10.1111/j.1365-2036.2008.03609.x , by HILL PG & Holmes GKT, Departments of Chemical Pathology and Gastroenterology, Derbyshire Royal Infirmary, Derby, UK. [E-mail: