Gluten-dependent small bowel mucosal transglutaminase 2-specific IgA deposits in overt and mild enteropathy coeliac disease.
OBJECTIVE
In coeliac disease, immunoglobulin (Ig)A-class autoantibodies against transglutaminase-2 are produced in the small intestinal mucosa, where they are deposited extracellularly. It remains unclear whether positive intestinal transglutaminase-2-targeted IgA deposits in subjects having normal small bowel mucosal morphology are signs of early-stage coeliac disease. We evaluated the gluten dependency of these deposits in overt and mild enteropathy coeliac disease.


METHODS
All together 48 subjects suspected of coeliac disease but having normal small bowel mucosal villi were enrolled; 28 of them had latent coeliac disease. The remaining 20 having positive intestinal IgA deposits adopted a gluten-free diet before villous atrophy had developed. For comparison, 13 patients with overt coeliac disease and 42 noncoeliac controls were studied. Small bowel mucosal transglutaminase-2-specific autoantibodies were compared with villous morphology, intraepithelial lymphocyte densities, and serum coeliac autoantibodies.


RESULTS
Intestinal IgA deposits were seen in all but 1 of the patients with latent coeliac disease, when the morphology was still intact; the intensity of these deposits increased as villous atrophy developed and decreased again on a gluten-free diet. In 20 patients with intestinal IgA deposits in normal villi, the intensity of the deposits decreased with the diet similarly to that seen in patients with overt coeliac disease. Mucosal IgA deposits were seen initially only in 5% of noncoeliac controls and in 8% after extended gluten consumption.


CONCLUSIONS
The response of small bowel mucosal transglutaminase-2-specific IgA deposits for dietary intervention was similar in overt and mild enteropathy coeliac disease. Detection of such IgA deposits thus offers a good diagnostic tool to uncover early-stage coeliac disease.
Koskinen
Outi
O
Pediatric Research Centre, University of Tampere, Finland.
Collin
Pekka
P
Korponay-Szabo
Ilma
I
Salmi
Teea
T
Iltanen
Sari
S
Haimila
Katri
K
Partanen
Jukka
J
Mäki
Markku
M
Kaukinen
Katri
K
D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers; D002446:Celiac Disease / Q000175:diagnosis* / Q000178:diet therapy / Q000276:immunology / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D019204:GTP-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D005983:Glutens / Q000008:administration & dosage*; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis*; D007413:Intestinal Mucosa / Q000276:immunology / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases / Q000276:immunology / Q000378:metabolism*; D055815:Young Adult
D015415:Biomarkers; D007070:Immunoglobulin A; D005983:Glutens; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins