Increasing numbers at a specialist coeliac clinic: contribution of serological testing in primary care

Serological testing, using IgA class endomysial and tissue transglutaminase antibodies has high sensitivity and specificity for coeliac disease and allows case finding by clinicians other than gastroenterologists. We reviewed new coeliac patients seen over a 9-year period to determine how the availability of serology, particularly to primary care physicians, has changed rates and sources of diagnosis.

Files of patients attending a specialist coeliac clinic who were diagnosed from 1996 through 2004 were reviewed. Patients with villous atrophy consistent with gluten sensitive enteropathy (Marsh III) on duodenal biopsy were selected. Data analysed included clinical characteristics, endomysial and tissue transglutaminase antibodies status and source of request for serology.

Over the study period 347 new coeliac patients, comprising adults and children aged 10 years and over, were identified, of whom 163 (47%) were identified by serological testing in primary care, 152 (44%) at the hospital gastroenterology department and 32 (9%) by other physicians in secondary care. Over three consecutive 3-year periods, the percentage of patients identified in primary care rose from 28% through 47% to 60%, with a rise in total numbers diagnosed from 93 through 118 to 136. There was no change in patient clinical characteristics over the study period. Though tissue transglutaminase antibodies were less sensitive than endomysial antibodies, combined testing obtained a sensitivity of over 90%. Patients identified in primary care were significantly younger and more likely to present with diarrhoea as a primary symptom.

Currently over half of our coeliac patients are identified by serological testing in primary care, which has resulted in an overall rise in diagnosis rates. Primary care practitioners have an important role in the diagnosis of coeliac disease, particularly of patients who present with non-gastrointestinal symptoms. The contribution of specialists other than gastroenterologists in secondary care is disappointing and may improve with directed education.