FURTHER-STUDIES OF ANTI-ENDOMYSIUM AND ANTIGLIADIN ANTIBODIES IN PATIENTS WITH SUSPECTED CELIAC-DISEASE

Background: The findin,o of characteristic small intestinal mucosal ab normalities on histologic examination of a biopsy specimen remains the first requirement for the diagnosis of celiac disease. A reliable and noninvasive test would be ideal for the patient's convenience and for reducing health-care costs, The sensitivity and specificity of anti-g liadin antibodies (AGA-immunoglobulin [Ig] G, AGA-IgA) have been varia ble; anti-endomysium IgA (EmA-IgA) is more helpful. In an earlier stud y conducted at the authors' institution, celiac disease was present in 19 patients examined from 1992 to 1995. Anti-endomysium titers were h igher than normal in all 19 patients (100%). Total villous atrophy was seen in 14 of 17 biopsy specimens (82%) and subtotal atrophy in 3 (18 %). The purpose of the current study was to evaluate further the accur acy of EmA-IgA in diagnosing celiac disease. Methods: One hundred seve n patients were screened for celiac disease between March 1996 and Jul y 1997. The level of EmA-IgA was measured in all patients, and AGA-IgG and AGA-IgA were measured in 104 patients. Forty-six patients underwe nt endoscopic biopsy of the small bowel, with measurement of disacchar idase enzymes in 45 patients. Results: Five of 46 patients had celiac disease (three boys and two girls; mean age: 5.3 years; 2-9.5 years); one also had cystic fibrosis and another had insulin-dependent diabete s mellitus. All five had marked to complete villous atrophy with crypt hyperplasia and increased serum EmA-IgA (100% sensitivity). None of t he remaining patients had increased EmA-IgA (100% specificity). Serum levels of AGA-IgG and AGA-IgA were increased in all four celiac diseas e patients (100% sensitivity), but they were also high in patients wit hout celiac disease (38% and 92% specificity, respectively), which com promises their diagnostic value. None of the patients confirmed to hav e celiac disease had IgA deficiency. Abnormal disaccharidase enzyme ac tivities were documented in all five celiac disease patients: severe g eneralized deficiency (n = 2), moderately severe generalized deficienc y tit = 2), and alactasia with moderate deficiency of the a-glucosidas es (n = 1). Conclusions: This study confirmed the reliability and accu racy of EmA-IgA in the diagnosis of celiac disease. Small bowel biopsy may be unnecessary in EmA-positive patients in whom celiac disease is suspected.