Evaluation of the Virclia® automated chemiluminescent immunoassay system for diagnosing pneumonia caused by Mycoplasma pneumoniae.

Abstract

Mycoplasma pneumoniae is considered an important etiologic agent of community-acquired pneumonia (CAP) in outpatients. We aimed to evaluate the diagnostic accuracy of a quick automated chemiluminescent immunoassay (CLIA) for M.pneumoniae in a population-based prospective study of CAP. A total of 137 outpatients diagnosed with CAP were included in the study. Acute- and convalescent phase sera were analyzed for IgG and IgM to M.pneumoniae with both CLIA (VirClia® ) and ELISA immunoassays. Conventional serological criteria by quantitative ELISA were considered as reference standard. Sensitivity and specificity of the assay were assessed with the construction of receiver operating characteristic (ROC) curves, and the kappa index was used to evaluate the accuracy of the IgG and IgM determinations in the acute phase. Thirty-eight patients were diagnosed with pneumonia by M.pneumoniae. ROC curves for IgG and IgM of convalescent and acute phase (C/A) quotients by the CLIA and ELISA assays were comparable. Specifically, for the CLIA, the best C/A quotient for IgG was 2.617 (sensitivity, 94.9%; specificity, 99.9%), and for IgM 1.400 (sensitivity, 65.8%; specificity, 100%). Regarding the acute phase, the best diagnostic accuracy for the CLIA was obtained with an IgG index of 1.120 (sensitivity, 89.5%; specificity, 73.7%). The CLIA was very simple to execute and required a minimum sample handling. The accuracy of the Virclia® assay for the diagnosis of M.pneumoniae infection in outpatients with CAP was equivalent to the quantitative ELISA. The CLIA was quicker to perform and displayed better analytic workability than conventional ELISA.