Serum Tumor Necrosis Factor-αand Interferon-γLevels in PediatricMycoplasma pneumoniaePneumonia: A Systematic Review and Meta-Analysis
Background.Mycoplasma pneumoniaepneumonia (MPP) is one of the most common forms of community-acquired pneumonia in children. The objective of this study was to explore potential changes in levels of serum tumor necrosis factor-α(TNF-α) and interferon-γ(IFN-γ) associated with pediatric MPP.Methods. This protocol has been registered (PROSPERO 2017: CRD42017077979). A literature search was performed in October 2017 using PubMed, Embase, the Cochrane Library, and other Chinese medical databases to identify studies. The meta-analysis was performed using Review Manager 5.3 software. Random-effect models were used to estimate mean differences (MDs) and 95% confidence intervals (CIs) of cytokine levels.Results. Twelve studies were included in the meta-analysis, encompassing 2,422 children with MPP and 454 healthy control children. Serum TNF-αlevels were significantly higher in children with MPP compared with healthy children (MD = 22.5, 95% CI = 13.78–31.22,P<0.00001), and there was significant heterogeneity across studies (I2 = 100%,P<0.00001). Subgroup analyses showed no evidence for a difference in serum TNF-αlevels between children with refractory and nonrefractory MPP. Serum IFN-γlevels did not significantly differ in children with MPP compared with healthy children (MD = 4.83, 95% CI = −3.27–12.93,P=0.24).Conclusions. Our meta-analysis showed that serum TNF-αand IFN-γlevels were significantly elevated and unchanged, respectively, in pediatric MPP. Because infection by different pathogens has variable effects on serum TNF-αand IFN-γlevels, the finding could be helpful in developing novel diagnostic methods.