Objective: Although serum IgA-class endomysial antibody (EmA) has high sensitivity for villous atrophy (VA) in patients with untreated celiac disease, few studies have attempted to correlate EmA seroconversion with histological recovery after starting a gluten-free diet. We prospectively studied changes in EmA status and in duodenal histology of seropositive patients after dietary treatment.
Methods: Patients with VA and EmA had repeat EmA testing at 3, 6, and 12 months after starting gluten-free diet, plus assessment of dietary compliance by dietitians and follow-up duodenal biopsy at 12 months. VA before and after treatment was classified as partial (P), subtotal (ST), and total (T).
Results: Of 77 patients with newly diagnosed VA and without IgA deficiency, 62 (81%) had EmA: 46 of 57 (81%) with T or STVA and 16 of 20 (80%) with PVA. Of 53 initially EmA-positive patients who completed study criteria, EmA was undetectable in 31 patients (58%) after 3 months' diet, in 40 (75%) after 6 months, and in 46 (87%) after 12 months. However, only 21 patients (40%), all seronegative by 12 months, had complete villous recovery. Only three (33%) of 10 patients with persisting ST or TVA and two (9%) of 22 with PVA remained EmA positive. Four of the five patients with persisting EmA had poor dietary compliance.
Conclusions: EmA is a poor predictor of persisting VA after patients have started gluten-free diet, although it may be of value in monitoring dietary compliance. Although there are no clear guidelines regarding the need for follow-up biopsy, EmA seroconversion cannot substitute. The apparent association between dietary compliance and seroconversion suggests that gluten intake may determine whether untreated celiac patients are EmA positive or negative for a given degree of small bowel damage.