OBJECTIVE To explore the levels of peripheral blood micro ribonucleic acid (miR)-1323, regulate and activate normal T cell expression and secretion factors(RANTES), T cell immunoglobulin mucin molecule 3 (TIM-3) and high mobility group protein B1 (HMGB1) of the children with refractory Mycoplasma pneumoniae pneumonia and analyze the association with the severity of disease.

METHODS A total of 97 children with refractory M. pneumoniae pneumonia who were treated in the Second Affiliated Hospital of Hainan Medical College from May 2020 to May 2023 were assigned as the study group, meanwhile, 103 healthy children who received physical examination were chosen as the control group. The expression levels of peripheral blood RANTES, TIM-3, HMGB1 and miR-1323 were detected by respectively using enzyme-linked immunosorbent assay (ELISA) and real-time fluorescence quantitative polymerase chain reaction (RT-qPCR).

RESULTS The levels of RANTES, TIM-3, HMGB1 and miR-1323 of the study group were significantly higher than those of the control group(P < 0.05). Among the children with refractory M. pneumoniae pneumonia, the levels of RANTES, TIM-3, HMGB1 and miR-1323 of the moderate group and the severe group were significantly higher than those of the mild group(P < 0.05), the levels of above indexes of the severe group were significantly higher than those of the moderate group(P < 0.05). The result of Spearman correlation analysis showed that the RANTES, TIM-3, HMGB1 and miR-1323 were positively correlated with the severity of disease of the children with refractory M. pneumoniae pneumonia(P < 0.05).

CONCLUSION The children with refractory M. pneumoniae pneumonia show the high expressions of RANTES, TIM-3, HMGB1 and miR-1323, which are closely associated with the severity of disease.