A Comparison of Immuncapture Agglutination and ELISA Methods in Serological Diagnosis of Brucellosis

Background: Different serological tests are used in serologic diagnosis of brucellosis. The most widely used of these are Standard Tube Agglutination and Coombs anti-brucella tests. Whereas ELISA Ig M and Ig G tests have been in use for a long time, immuncapture agglutination test has been recently introduced and used in serological diagnosis. The aim of this study was to compare diagnostic values of ELISA Ig M and Ig G and immuncapture agglutination tests with Coombs anti-brucella test. Methods: Sera from 200 patients with presumptive diagnosis of brucellosis were included into the study. Coombs anti-brucella test, ELISA Ig M and Ig G tests and Immuncapture test were investigated in these sera. Then, sensitivity, specificity, negative predictive and positive predictive values were calculated. Results: Sensitivity, specificity, negative predictive and positive predictive values were found to be 90,6 %, 76,3 %, 94,2 %, and 65,9 % respectively for the Immuncapture test, whereas they were found to be 73,7 %, 58,9 %, 84,2 %, and 42,8 % for Ig G and 72,2 %, 67,8 %, 85,2 %, and 48,7 % for Ig M. The Immuncapture test was found to be compatible with ELISA Ig M and Ig G tests but it was statistically incompatible with Coombs anti-brucella test. Conclusions: Immuncapture agglutination test yields similar results to those of Coombs anti-brucella test. This test is a useful test by virtue of the fact that it determines blocking antibodies in the diagnosis and follow-up of brucellosis.