Early diagnostic value of the antimycoplasma antibody (IgM) in Mycoplasma pneumoniae pneumonia: A single-center study in 2015

ABSTRACT

PURPOSE: Recently, the incidence of refractory Mycoplasma pneumoniae (MP) pneumonia has increased in Korea. Given that its early diagnosis is helpful in selection of the treatment, this study aimed at investigating the value of the antimycoplasma antibody (IgM) for early diagnosis of MP pneumonia. METHODS: A total of 315 children admitted with MP pneumonia from September 2015 to May 2016 were investigated with the IgM and polymerase chain reaction (PCR) for the diagnosis of MP pneumonia. Specifically, patients were grouped into nonrefractory respiratory MP and refractory MP groups according to their response to macrolide therapy. RESULTS: In the 44 PCR-negative seroconversed children, seroconversed IgM was more frequent in the refractory MP group compared with the nonrefractory respiratory MP group with statistical significance (P<0.001). In the 264 IgM-positive children, the time of antibody reaction was more delayed in the refractory MP group compared to the nonrefractory respiratory MP group with statistical significance (P<0.001). CONCLUSION: This study showed that there was a higher incidence of seroconversed IgM and delayed antibody reaction in the refractory MP group. In children with suspect MP pneumonia, follow-up studies of antibody are necessary, even through initial antibody and PCR showed negative findings. In addition, this result may suggest that the diagnosis of refractory MP pneunomia will be helpful in establishing the strategy of the treatment.