Serum Antibody Responses Associated with Clinical Features of Mycoplasma pneumoniae Pneumonia

Kim, Ji Young; Lee, Hyun Ju; Chung, Hai Lee

Abstract

PURPOSE
Serum specific IgM and IgG responses have been used to diagnose Mycoplasma pneumoniae (M. pneumoniae) infection. The aim of this study was to investigate the relationship between antibody responses and the clinical features of M. pneumoniae pneumonia.
METHODS
Eighty-five children admitted due to M. pneumoniae pneumonia were enrolled. Serum specific IgM and IgG were measured semiquantatively by ELISA, and acute infection was determined by IgM concentration above the specified cutoff value. Recurrent M. pneumoniae pneumonia was defined as a history of proven M. pneumoniae pneumonia before at least 12 months with positive IgG, while the first pneumonia was defined as no past history of pneumonia with negative IgG. Both IgM titer and symptom duration were evaluated whether the patients had recurrent or the first M. pneumoniae pneumonia, they had current asthma or not and they presented wheeze during admission.
RESULTS
Significantly higher specific IgM titers were observed in patients with recurrent pneumonia than those without.(P<0.01) The IgM titer was higher in patients with asthma than those without which was not statistically significant.(P=0.08) Significantly prolonged symptoms were observed in patients with asthma (P<0.05) and those with wheezing during admission. (P<0.01) The highest IgM titer was observed in asthmatic children with recurrent M. pneumoniae pneumonia.
CONCLUSION
Our study shows that significantly higher specific IgM titer in the children with recurrent M. pneumoniae pneumonia comparing with their counterparts, which was more prominent in asthmatic patients. Further studies are needed to evaluate the clinical significance of an increased serum antibody level in recurrent M. pneumoniae pneumonia.