Combination testing for antibodies in the diagnosis of coeliac disease: comparison of multiplex immunoassay and ELISA methods

• Published in: Alimentary pharmacology & therapeutics 2008-09, Vol.28 (6), p.805-813
• Main Authors: RASHTAK, S., ETTORE, M. W., HOMBURGER, H. A., MURRAY, J. A.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies - blood; Biological and medical sciences; Biopsy; Case-Control Studies; Celiac Disease - diagnosis; Celiac Disease - immunology; Celiac Disease - pathology; Child; Child, Preschool; Data Interpretation, Statistical; Digestive system; Enzyme-Linked Immunosorbent Assay; Female; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Immunoassay - methods; Immunoglobulin A - immunology; Immunoglobulin G - immunology; Male; Medical sciences; Middle Aged; Other diseases. Semiology; Pharmacology. Drug treatments; Sensitivity and Specificity; Stomach. Duodenum. Small intestine. Colon. Rectum. Anus; Young Adult
• ISSN: 0269-2813; 1365-2036
• DOI: 10.1111/j.1365-2036.2008.03797.x

Summary Background  Tissue transglutaminase (TTG) antibodies and newly developed deamidated gliadin peptide (DGP) antibodies have better accuracy than native gliadin antibodies. Multiplex immunoassay (MIA) measures multiple antibodies simultaneously providing a complete antibody phenotype with reduced turnaround time and cost. Aim  To evaluate the agreement between MIA and enzyme‐linked immunosorbent assay (ELISA) test results for coeliac antibodies in biopsy‐proven coeliac patients and controls and to model the diagnostic utility of combination testing. Methods  We compared the sensitivity, specificity and accuracy of MIA and ELISA methods for TTG and DGP antibodies in mainly adult untreated coeliac patients (n = 92) and controls (n = 124). Results  There was excellent agreement and a significant correlation between the results of MIA and ELISA methods (κ > 0.8, r > 0.7) for all tests, except TTG IgG. Diagnostic indices of individual and combination tests measured by the MIA method did not differ significantly from those measured by ELISA. The combination tests slightly increased sensitivity (if any test was positive) and specificity (if all tests were positive) compared to the individual tests. Conclusions  Multiplex immunoassay testing for antibodies is as accurate as ELISA for coeliac disease diagnosis and has practical advantages over ELISA method. Rational combination testing can help identify patients who need intestinal biopsy and may reduce unnecessary biopsies.