A prediction study of IL-18 and IFN-γ in glucocorticoid treatment response in infants and young children with severe Mycoplasma pneumoniae pneumonia

BACKGROUND: In infants and young children, the clinical decision to apply glucocorticoids to severe Mycoplasma pneumoniae pneumonia (SMPP) is more an empirical choice with reference to clinical symptoms, but the effect is not satisfying. We aimed to explore and identify early predictive indicators of ideal response to glucocorticoids treatment in SMPP in infants and young children. METHODS: We retrospectively reviewed the data of 59 patients, which met the age range and diagnostic criteria, admitted to Department of Pediatrics, the Sixth People’s Hospital Affiliated to Shanghai Jiaotong University, from January to December 2017. Patients were divided into a glucocorticoid treatment group and a normal treatment group according to whether glucocorticoid treatment was used, and the difference in therapeutic effectiveness was compared between two groups. The glucocorticoid treatment group was further subdivided into effective versus ineffective treatment groups dependent on the difference of glucocorticoid treatment effect in main clinical symptoms improvement. We obtained the test value of biomarkers by ELISA, and identified several specific indicators with significantly different expressions in the early stage by independent sample t-tests and calculated their cut-off values by ROC curve. RESULTS: Thirty-one SMPP patients who received glucocorticoid treatment were divided into effective and ineffective treatment groups according to the clinical improvements shown on different days of glucocorticoid use. The expression of two markers, interleukin-18 (IL-18) and interferon-γ (IFN-γ), were significantly different in cases showing improvement in the early stage of SMPP (P<0.05), and the cut-off values for IL-18 (218.19 pg/mL, AUC =0.581, sensitivity =0.909, 1-specificity =0.786) and IFN-γ (11.24 pg/mL, AUC =0.566, sensitivity =0.905, 1-specificity =0.795) were identified. CONCLUSIONS: The expressions of IL-18 and IFN-γ in the early stage of SMPP might suggest their predictive effect of early application of glucocorticoid for effective treatment of SMPP in infants and young children. Further study with larger sample size will be carried on in the future.