Background Over the previous several months we have noticed an increased false-positive coeliac serology rate in patients referred from a particular catchment area of our centre. We investigated serologic methods employed and compared it to methods used at our centre and other hospitals in our catchment.
Methods The authors investigated serological methods employed to screen 67 patients referred for histological conformation of coeliac disease to our service in the previous year (2008). Pathology departments in referring hospitals were contacted to ascertain serological methods used. Coeliac disease was diagnosed based on biopsy evidence (gold standard). Predictive values for the screening serological tests were calculated.
Conclusion Positive predictive values vary significantly between commercially available tTG kits. When faced with a high false-positive trend it is worthwhile investigating laboratory methods used, bench marking against reference laboratories and standardising serological testing.