Objectives: The purpose of this study was to explore the clinical and laboratory characteristics of children
with refractory Mycoplasma pneumoniae pneumonia (RMPP).
Methods: Seventy-six children with RMPP and 26 children with non-refractory M. pneumoniae
pneumonia (NRMPP), confirmed by both serology and fluorescent quantitation PCR in bronchoalveolar
lavage fluid (BALF), were evaluated retrospectively.
Results: Compared to those with NRMPP, children with RMPP were older (66.6 39.0 vs.
48.4 35.4 months, p = 0.038) and had a longer duration of fever (12.7 2.6 vs. 7.5 1.8 days) and
hospital stay (12.1 3.2 vs. 7.4 2.9 days). Children with RMPP presented neutrophil infiltration both in
serum and BALF, as well as severe pulmonary lesions with pleural effusion. Children with RMPP had a
significantly higher M. pneumoniae DNA load in BALF compared to NRMPP patients, and the M. pneumoniae
load in BALF was significantly correlated with neutrophils and inversely correlated with macrophages for
both the NRMPP and RMPP groups. The serum concentrations of tumor necrosis factor alpha (median
114.5 pg/ml, range 49.1–897.9 pg/ml) and interferon gamma (median 376.9 pg/ml, range 221.4–1997.6 pg/
ml) were significantly higher in children with RMPP compared to children with NRMPP.
Conclusions: This study indicates that a direct microbe effect and the subsequent induced excessive host
immune response contribute in part to the progression of RMPP.
2014 The Authors. Published by Elsevier Ltd on behalf of International Society for Infectious Diseases.
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