Anti-transglutaminase antibodies and the serological diagnosis of coeliac disease.
Tissue transglutaminase (tTG) has recently been identified as the antigenic target recognised by anti-endomysial antibodies in patients with coeliac disease. In this study, an enzyme-linked immunosorbent assay (ELISA) is used to measure IgA, IgG and IgM antibodies to tTG in patients with coeliac disease and a variety of other inflammatory disorders; and is compared to the standard immunofluorescence test used to detect endomysial antibodies (EMA). In the samples tested, 3% control sera (n=146), 83% EMA-positive sera (n=29), 9% patients with Graves' disease (n=94), 12% antimitochondrial antibody-positive sera (n=53), 11% rheumatoid arthritis patients (n=53) and 22% systemic lupus erythematosus (SLE) patients (n=46) were positive for anti-tTG antibodies. In contrast, none of the controls, 1% of patients with Graves' disease, 2% antimitochondrial antibody-positive sera, 2% rheumatoid arthritis patients and none of the SLE patients were positive for EMA. Measurement of IgG or IgM antibodies to tTG was much less reliable than IgA anti-tTG antibody for the serological diagnosis of coeliac disease. The addition of calcium to the coating buffer improved the assay characteristics of the anti-tTG ELISA. However, the IgA anti-tTG ELISA, with and without calcium, performed less well than the standard EMA test used for the serological diagnosis of coeliac disease. In particular, the anti-tTG ELISA gave a higher rate of non-specific positive reactions.
Feighery
L
L
Department of Immunology, St. James's Hospital, Trinity College Dublin, Ireland.
Collins
C
C
Feighery
C
C
Mahmud
N
N
Coughlan
G
G
Willoughby
R
R
Jackson
J
J
D000906:Antibodies / Q000032:analysis*; D001327:Autoimmune Diseases / Q000276:immunology*; D002118:Calcium / Q000494:pharmacology; D002446:Celiac Disease / Q000175:diagnosis / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D011503:Transglutaminases / Q000276:immunology*
D000906:Antibodies; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011503:Transglutaminases; D002118:Calcium