Serum IgA tissue transglutaminase antibodies in coeliac disease and other gastrointestinal diseases

DAHELE, A. V.M.
ALDHOUS, M. C.
HUMPHREYS, K.
GHOSH, S.

From the Gastrointestinal Unit, Department of Medical Sciences, University of Edinburgh, Western General Hospital, Edinburgh, UK

Received 21 January 2000 and in revised form 12 February 2001

Address correspondence to Dr S. Ghosh, Gastrointestinal Unit, Western General Hospital, Edinburgh EH4 2XU. e-mail: sg@srvø.med.ed.ac.uk

Quarterly Journal of Medicine 94(4):p 195-205, April 2001.

Summary

We investigated the presence of IgA anti-tissue transglutaminase (tTG) antibodies in untreated coeliac disease (CD) and other gastrointestinal diseases, and compared IgA tTG concentrations with anti-endomysium (EMA) immunofluorescent findings. The study included 116 untreated CD patients (74 female, 42 male, age range 15-78 years, median 47 years), 82 treated CD patients, 65 patients with normal duodenal histology, 260 disease control samples and 29 healthy volunteers. IgA anti-tTG, EMA, and anti-gliadin (AGA) antibodies were measured. Serum total IgA was measured in the CD patients. Two IgA-deficient untreated CD patients were excluded. IgA EMA and IgA AGA were positive in 99 (87%) and 69 (61%), respectively, of the 114 untreated CD patients. Elevated IgA anti-tTG were found in 92/114 (81%) untreated coeliacs, 1/82 (1%) treated coeliacs, 2/65 (3%) non-coeliacs, 10/260 (4%) disease controls and 2/29 (7%) volunteers. Four of the untreated CD patients, with a normal serum total IgA concentration, were negative for all the serological tests. IgA anti-tTG concentrations were significantly higher in untreated coeliacs (median 10 200 units/ml) than in other groups (Mann-Whitney, p<0.00001) and compared well with IgA EMA titres (r²=0.54; p<0.0001).