The detection of complement fixing antibodies by ELISA (COMPELISA) in Brucella serology

The detection of complement fixation by enzyme linked immunosorbent assay (COMPELISA) has several advantages over the conventional complement fixation test (CFT). COMPELISA does not require sheep red blood cells and can be used in those geographical regions where this product is not readily available. In the COMPELISA technique the test serum and the complement are never combined and therefore any anticomplementary substances in the blood do not affect the result. Furthermore, serum samples can be treated with 2-mercaptoethanol (ME), a very anticomplementary reagent, and the effect which the resultant breakdown of IgM immunoglobulin has on complement fixation can be studied. The effect of ME is normally observed on agglutinins only. Results of the COMPELISA and other tests on sera from patients at various stages of brucellosis are presented for comparison. They show that the COMPELIA and ME-COMPELISA together reflect the patient's immune status as accurately as other conventional tests and it is suggested that they would constitute an effective and rapid (half-day) screening procedure where large numbers of human or animal sera are to be examined.