| Objective To investigate the relationship between serum microRNA-21 (miR-21), sphingosine-1-phosphate (S1P) and liver injury in children with refractory mycoplasma pneumoniae pneumonia (RMPP). Methods 270 children with RMPP (RMPP group) and 174 healthy children (control group) who were admitted to our hospital from January 2021 to October 2023 were selected, children with RMPP were divided into liver injury group (≥40 U/L, 39 cases) and non liver injury group (<40 U/L, 231 cases) according to the level of alanine aminotransferase (ALT), and children with liver injury were divided into mild liver injury group (40U/L~< 200U/L, 20 cases ), moderate liver injury group (200U/L~< 400U/L, 13 cases) and severe liver injury group (≥400U/L, 6 cases). The level of miR-21 was detected by real-time fluorescence quantitative polymerase chain reaction (RT-PCR), and the level of S1P was detected by enzyme-linked immunosorbent assay. The influencing factors of liver injury in children with RMPP were analyzed by univariate and multivariate logistic regression, the predictive value of serum miR-21 and S1P levels for liver injury in children with RMPP were analyzed by receiver operating characteristic (ROC) curve. Results Compared with control group, the serum miR-21 level in RMPP group was increased, and the S1P level was decreased (P<0.05). The levels of serum miR-21 in non liver injury group, mild liver injury group, moderate liver injury group and severe liver injury group increased in turn, and the levels of S1P decreased in turn (P<0.05). Univariate and multivariate logistic regression analysis showed that prolonged fever, elevated serum CRP level and elevated serum miR-21 level were risk factors for liver injury in children with RMPP, and elevated serum S1P level was a protective factor (P<0.05). The area under the curve (AUC) of serum miR-21 combined with S1P level in predicting liver injury in children with RMPP was 0.887, which was greater than 0.785 and 0.784 predicted by serum miR-21 and S1 P levels alone (P<0.05). Conclusion The increase of serum miR-21 level and the decrease of S1P level are related to the degree of liver injury in children with RMPP, and serum miR-21 combined with S1P level has a high predictive value for liver injury in children with RMPP. |
