Predictive value of C-reactive protein in response to macrolides in children with macrolide-resistant Mycoplasma pneumoniae pneumonia

Purpose: The prevalence of macrolide-resistant Mycoplasma pneumoniae (MRMP) has increasedworldwide. The aim of this study was to estimate the proportion of MRMP in a tertiary hospital in Korea,and to find potential laboratory markers that could be used to predict the efficacy of macrolides in childrenwith MRMP pneumonia. Methods: A total of 95 patients with M. pneumoniae pneumonia were enrolled in this study. Detectionof MRMP was based on the results of specific point mutations in domain V of the 23S rRNA gene. Themedical records of these patients were reviewed retrospectively and the clinical course and laboratorydata were compared. Results: The proportion of patients with MRMP was 51.6% and all MRMP isolates had the A2063G pointmutation. The MRMP group had longer hospital stay and febrile period after initiation of macrolides. The levels of serum C-reactive protein (CRP) and interleukin-18 in nasopharyngeal aspirate were significantlyhigher in patients who did not respond to macrolide treatment. CRP was the only significant factor inpredicting the efficacy of macrolides in patients with MRMP pneumonia. The area under the curve forCRP was 0.69 in receiver operating characteristic curve analysis, indicating reasonable discriminativepower, and the optimal cutoff value was 40.7 mg/L. Conclusion: The proportion of patients with MRMP was high, suggesting that the prevalence of MRMPis rising rapidly in Korea. Serum CRP could be a useful marker for predicting the efficacy of macrolidesand helping clinicians make better clinical decisions in children with MRMP pneumonia. KCI Citation Count: 6