A modified ELISA for improved detection of IgA, IgG, and IgM anti-tissue transglutaminase antibodies in celiac disease.
BACKGROUND
Serum IgA antibodies against tissue transglutaminase (tTG) are reliable markers for celiac disease (CD), still the diagnostic performance of anti-tTG immunoassays can be improved. A novel ELISA, using fibronectin (FN) as tTG binding protein, was evaluated for the detection of anti-tTG antibodies in CD.


METHODS
Sera from 173 children with untreated CD and 97 controls were analyzed for IgA, IgG, and IgM anti-tTG antibodies with ELISA using human recombinant tTG with or without FN.


RESULTS
The areas under the ROC (receiver operating characteristic) curves were significantly higher for FN/tTG ELISA compared to tTG ELISA for IgG (0.930 versus 0.809; p < 0.001) and IgM (0.850 versus 0.811; p = 0.019), but not for IgA (0.977 versus 0.970; p = 0.356), respectively. At the fixed diagnostic specificity (100% for IgA and IgM, 99% for IgG), the sensitivity of all three FN/tTG ELISA (92.5% for IgA, 60.7% for IgG, 50.3% for IgM) exceeded those obtained in tTG ELISA (89.0% for IgA, 48.6% for IgG, 38.7% for IgM; p < 0.05). The combined use of IgA- and IgG-FN/tTG ELISA resulted in 95.4% sensitivity and 99.0% specificity for CD.


CONCLUSIONS
Using FN to bind tTG improves the diagnostic performance of solid phase anti-tTG antibody assays for childhood CD.
Teesalu
Kaupo
K
Immunology group, Department of General and Molecular Pathology, University of Tartu, Tartu, Estonia. kaupo.teesalu@ut.ee
Agardh
Daniel
D
Panarina
Marina
M
Utt
Meeme
M
Uibo
Oivi
O
Uibo
Raivo
R
D001774:Blood Chemical Analysis / Q000379:methods*; D002446:Celiac Disease / Q000097:blood / Q000175:diagnosis* / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D005353:Fibronectins / Q000378:metabolism; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood / Q000276:immunology; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000097:blood* / Q000276:immunology*; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D008297:Male; D011503:Transglutaminases / Q000276:immunology* / Q000378:metabolism
D005353:Fibronectins; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007075:Immunoglobulin M; D011503:Transglutaminases