Comparative studies of three serologic methods for the measurement of Mycoplasma pneumoniae antibodies.
Antibodies against Mycoplasma pneumoniae in the sera of patients and normal adult controls were measured by a standard complement fixation (CF) test, a commercial immunofluorescence (IF) test (CROWNTITRE), and a commercial enzyme-linked immunosorbent assay (ELISA) (MYCOPLASMELISA). The findings showed that, in the control sera, 269 of 277 (97%) had negative results for CF antibodies. Of the 320 controls tested by the IF assay, all (100%) had negative results for IgM antibodies and 314 (98%) had negative results for IgG antibodies. Only 6 of the 201 (3%) controls by the ELISA were classified as negative/equivocal. Among the 450 patient sera, 105 (23%) had positive results for CF antibodies, and 158 (35%) had positive results for IgG and/or IgM membrane antibodies by the IF test; 424 of these patients' sera were also tested by the ELISA, and 397 (94%) of them were found to have positive results for anti-M. pneumoniae IgG antibodies. If the CF test were chosen as the standard for comparison, the IF test would have a sensitivity of 87% and a specificity of 81% and the ELISA would have a sensitivity of 71% and a specificity of 80%, provided an adjustment in the threshold ELISA-positive value was made. A single positive M. pneumoniae membrane IgM antibody titer appeared to be valuable for a presumptive diagnosis of an ongoing infection; 41 of 47 (87%) of the IgM-positive results in the paired sera were supported by a fourfold increase or a stable high level of CF antibody titer.
Lee
S H
SH
Department of Pathology, Hospital of Saint Raphael, New Haven, Connecticut 06511.
Charoenying
S
S
Brennan
T
T
Markowski
M
M
Mayo
D R
DR
D000907:Antibodies, Bacterial / Q000032:analysis*; D003168:Complement Fixation Tests / Q000592:standards; D004797:Enzyme-Linked Immunosorbent Assay / Q000592:standards; D005455:Fluorescent Antibody Technique / Q000592:standards; D006801:Humans; D011019:Pneumonia, Mycoplasma / Q000276:immunology*; D011933:Reagent Kits, Diagnostic / Q000592:standards; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods*
D000907:Antibodies, Bacterial; D011933:Reagent Kits, Diagnostic