Abstract:

Objective To analyze the role of Mycoplasma pneumoniae（MP） RNA determination in the diagnosis and efficacy monitoring of pneumonia in children. Methods Totally，167 children with pneumonia in Zhengzhou Children's Hospital from May 2019 to January 2021 were enrolled. Sputum samples were collected for MP-RNA，MP-DNA，MP-IgG antibody and MP-IgM antibody determinations. The specificities and sensitivities of MP-DNA，MP-RNA，MP-IgM antibody and MP-IgG antibody for diagnosing MP were evaluated. The positive rate of MP-RNA and MP-DNA and the incidence of clinical symptoms after 1，2，3 and 4 weeks of treatment were analyzed. The duration of clinical symptoms and serum C-reactive protein（CRP），interleukin-8（IL-8） and white blood cell（WBC） count of children with different MP-RNA turn-negative time were compared. Results MP culture proved that 95 of 167 children were infected with MP. The specificities for diagnosing MP pneumonia in children were MP-RNA>MP-DNA>MP-IgM antibody>MP-IgG antibody. The sensitivities were MP-RNA>MP-IgM antibody>MP-DNA>MP-IgG antibody. The positive rates of MP-RNA and MP-DNA were negatively correlated with the duration of treatment（r=-0.901，P=0.017；r=-0.601，P=0.031）. For 2，3 and 4 weeks of treatment，the positive rate of MP-RNA was lower than that of MP-DNA（P<0.000 1）. Compared with MP-DNA，the incidence of cough after MP-RNA turn-negative was higher（P<0.05）. After 1，2，3 and 4 weeks of treatment，the duration of fever，cough，wheezing and pulmonary rales in MP-RNA turn-negative children were successively prolonged（P<0.000 1），and serum CRP，IL-8 and WBC count were successively increased on admission（P<0.000 1）. Conclusions MP-RNA and MP-DNA have certain diagnostic value in children with MP pneumonia. In contrast，MP-DNA is more suitable for the diagnosis of children with MP，and MP-RNA is suitable for monitoring the efficacy of children with MP.

Key words: Mycoplasma pneumoniae, DNA, RNA, Lower respiratory tract infection, Pneumonia, Diagnosis, Efficacy monitoring, Children