Antibodies to tissue transglutaminase C in type I diabetes.
OBJECTIVE
Silent coeliac disease is a gluten driven autoimmune disease which is relatively frequent in patients with Type I (insulin-dependent) diabetes mellitus. To determine the extent of gluten associated autoimmunity in Type I diabetes, autoantibodies to tissue transglutaminase C, a major autoantigen in coeliac disease, were measured in patients with new-onset Type I diabetes.


METHODS
We measured IgG and IgA tissue transglutaminase C autoantibodies using human recombinant antigen and radio-binding assays in a cohort of 287 patients with new-onset Type I diabetes, 119 with Type II (non-insulin-dependent) diabetes mellitus and in 213 control subjects.


RESULTS
We found IgA and IgG tissue transglutaminase C antibodies in 24 (8 %) patients with Type I diabetes; 97 (33 %) patients had IgG antibodies only and 1 IgA antibodies only. Antibody concentrations were highest in those with both IgA and IgG antibodies. Only 2 (2 %) patients with Type II diabetes and 2 (1 %) control subjects had either IgG or IgA tissue transglutaminase C antibodies. Patients with HLA DRB1(*)04 alleles had the highest prevalence of IgG tissue transglutaminase C antibodies.


CONCLUSIONS
These data show that almost 10 % of patients have autoimmunity typical of coeliac disease and that another 30 % have low level tissue transglutaminase C antibody binding. This high prevalence suggests either involvement of the gut in the pathogenesis of Type I diabetes or that transglutaminase is a secondary autoantigen resulting from beta-cell destruction. [Diabetologia (1999) 42: 1195-1198]
Lampasona
V
V
Department of Laboratory Medicine, San Raffaele Scientific Institute, Milan, Italy.
Bonfanti
R
R
Bazzigaluppi
E
E
Venerando
A
A
Chiumello
G
G
Bosi
E
E
Bonifacio
E
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000097:blood*; D002446:Celiac Disease / Q000150:complications / Q000175:diagnosis / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000276:immunology*; D005260:Female; D019204:GTP-Binding Proteins / Q000276:immunology*; D006684:HLA-DR Antigens / Q000096:biosynthesis; D059811:HLA-DRB1 Chains; D006650:Histocompatibility Testing; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D008875:Middle Aged; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011863:Radioimmunoassay; D011503:Transglutaminases / Q000276:immunology*
D001323:Autoantibodies; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D000091345:Protein Glutamine gamma Glutamyltransferase 2; D011503:Transglutaminases; D019204:GTP-Binding Proteins