The pattern of autoantibodies related to false negative results of serological tests in the diagnosis of human brucellosis

For the diagnosis of human brucellosis it is essential to perform diagnostic tests because of the wide variety of clinical manifestations of the disease. Serological tests are widely used for the diagnosis of brucellosis. However, blocking substances limit the use of standard tube agglutination test. Two hundred and forty two (242) serum samples were collected from healthy persons and persons in high-risk occupation. For each sample, the rose Bengal, IgM ELISA, IgG ELISA, serum tube agglutination test (SAT) and anti-nuclear antibody (ANA) tests were performed. Three sera in which rose Bengal or ELISA and ANA tests yielded positive results were having lower level of SAT titer. By an in vitroexperiment, efficacies of ANA nucleolar pattern to the false-negative reaction in the SAT were supported.   Key words: Human, brucella, serology, autoimmunity, test performance.