A comparison of complement fixation, indirect immunofluorescence for viral late antigens, and anti-complement immunofluorescence tests for the detection of cytomegalovirus specific serum antibodies.

It was shown that, on average, the titres of the sera obtained by both the anti-complement immunofluorescence (ACIF) and indirect immunofluorescence for viral late antigens (IFA-LA) procedures were approximately eight times higher than those obtained by complement fixation. There was no significant difference between the mean ACIF and IFA-LA titres, but the former method was preferred because it was not affected by non-specific staining. When 406 sera were screened for the presence or absence of antibodies, only five sera (1.2%) gave discordant results with the three tests. None of the tests could detect all of the sera that contained specific antibodies while each test detected over 98% of these sera. Thus, the increased sensitivity of the immunofluorescence procedures did not result in an appreciably increased rate of detection of cytomegalovirus seropositive sera.