Mycoplasma pneumoniae: IgG and IgM antibody response in presence of different antigens. Evaluation of commercial tests

Background. P1 adhesin protein (170-kDa) is responsible for the interaction between M. pneumoniae and the host. Such protein is the target of specific antibodies produced by the host in response to M. pneumoniae infection. Objectives. The aim of this study was to evaluate the performance of serological tests for Mycoplasma pneumoniae IgG and IgM on chemiluminescence analyzer LIAISON® and to demonstrate how the determination of specific antibodies is the main tool for accurate diagnosis of Mycoplasma infection. Study Design. Eighty-one unselected samples were assayed by ELISA kits Vircell IgG and IgM (bacterial lysate) and LIAISON® Mycoplasma IgG and IgM (recombinant protein P1). The discordant samples were tested with ELISA Savyon Serorecombinant IgG and IgM (recombinant protein P1) and reclassified according to the consensus rule. Results. Fifty-one samples were concordant between ELISA Vircell IgG and LIAISON® Mycoplasma IgG. After resolution of the 30 discordant: twenty-eight samples were classified concordant negative and one positive. Seventy-seven samples were concordant between ELISA Vircell IgM and LIAISON® Mycoplasma IgM. After resolution of 4 discordant samples: three samples were classified as negative. Conclusions. The higher correlation between LIAISON® and Savyon Serorecombinant is determined by the use of recombinant protein P1 in the solid phase and the type of cut-off calculation allows high specificity and sensitivity. The Mycoplasma pneumoniae IgG and IgM kits, performed in full automation on LIAISON® analyzer, show characteristics comparable to other kits and an easy handling of the sample.