Objective To investigate the predictive value of peripheral blood cell parametersneutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR) and atypical lymphocyte ratio (ALY%) on the risk of liver injury in children with infectious mononucleosis (IM).

Methods Ninety-two IM children hospitalized from 2019 to 2022 were selected as study subjects. The fasting venous blood cell parameters (NLR, MLR, ALY%) were collected at the first admission, and the three indicators were divided into high and low ratio groups with the median as the critical value, and the liver function related indicators of all subjects were also collected. The differences of liver function related indicators between two groups after admission were analyzed. The Spearman correlation analysis was used, and the receiver operating curve (ROC curve) was drawn to evaluate the predictive value of NLR, MLR and ALY% in the risk of liver injury of IM children.

Results Compared with high NLR group, MLR group and low ALY% group, the probability of liver injury in IM children in low NLR group, MLR group and high ALY% group was higher, and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) increased, the difference of which was statistically significant (P ＜ 0.05). The results of ROC curve analysis results showed that the area under ROC curve (AUC) of NLR, MLR and allotype lymphocyte ratio for predicting liver injury in IM children were 0.662, 0.627 and 0.688, respectively. In IM children, the NLR and MLR were negatively correlated with the expression levels of ALT, AST and LDH (P ＜ 0.05 to P ＜ 0.01), and the ALY% was positively correlated with the expression levels of ALT, AST and LDH (P ＜ 0.05 to P ＜ 0.01).

Conclusions Peripheral blood cell parameters have a certain predictive value for the risk of liver injury in IM children. The lower the NLR and MLR and the higher the ALY%, the more severe the injury degree in IM children with liver injury.