Serological diagnosis of cytomegalovirus infection: comparison of 8 enzyme immunoassays for the detection of HCMV-specific IgM antibody.
BACKGROUND
Recently, numerous commercial ELISA kits for the detection of HCMV-specific IgM antibodies have been developed and are available on the international market.


OBJECTIVE
The aim of the present study was to compare eight different ELISAs for the early serological diagnosis of HCMV infection.


METHODS
A panel of paired sera obtained from patients suffering from primary or secondary infection and potential cross-reactive serum samples positive for IgM antibodies against other herpesviruses, antinuclear antibody and rheumatoid factor were investigated with 5 indirect ELISAs (1-5) and 3 mu-capture assays (ELISAs 6-8).


RESULTS
The highest sensitivity for IgM detection was achieved by a mu-capture assay (ELISA 8) and a traditional indirect ELISA (4). Their respective sensitivities were 78.0 and 76.0%. Overall, mu-capture immunoassays (ELISAs 6-8) detected HCMV infection earlier than indirect ELISAs (1-5) and showed a higher sensitivity for antibody detection in dilution series of IgM positive serum samples. Whereas ELISAs 1, 2, 5 and 6 showed a specificity of 100%, the alternative assays were affected by a variable number of false positive results obtained by testing potential cross-reactive serum samples. Their specificities ranged from 72.0% (ELISA 8) to 96.0% (ELISA 3).


CONCLUSIONS
The results of the present study show that recent mu-capture and indirect ELISAs permit a relatively sensitive and reliable diagnosis of HCMV infection. Cross-reactive antigens and interference from antinuclear antibody may limit the specificity of commercial kits.
Weber
B
B
Institut für Med. Virologie, Zentrum der Hygiene, Universitätskliniken Frankfurt-am-Mainz, Paul Ehrlich Strasse 40, 60596 Frankfurt-am-Main, Germany.
Prosser
F
F
Munkwitz
A
A
Doerr
H W
HW