Aspartate aminotransferase (AST) /alanine aminotransferase (ALT) is a novel indicator to evaluate the prognosis of acute critical illness in recent years. At present, AST/ALT has only been reported to evaluate the prognosis of hemophagocytic lymphohistiocytosis (HLH) in adults, while HLH in children has not been studied.

To explore the relationship between AST/ALT and clinical characteristics and its prognostic significance in children with HLH, so as to provide a theoretical basis for early clinical recognition and diagnosis of HLH in children.

A total of 128 hospitalized children diagnosed with HLH in the Affiliated Hospital of Zunyi Medical University from January 2013 to May 2022 were selected as the research objects, and the baseline data of children were collected through the electronic medical record system. The children were divided into the T1 group (AST/ALT≤1.57, n=43), T2 group (1.57<AST/ALT<3.22, n=42), and T3 group (AST/ALT≥3.22, n=43) according to the AST/ALT quantiles, and followed up by outpatient review and telephone follow-up once every 6 months from the time of discharge to 2022-06-01, with the termination event of death or loss of follow-up. Spearman rank correlation analysis was used to explore the correlation between AST/ALT and laboratory test results. The receiver operating characteristic (ROC) curve of laboratory indicators for predicting death in children with HLHwas plotted, the area under ROC curve (AUC) and optimal cut-off value were calculated. Kaplan-Meier method was used to plot survival curves to analyze the effect of different AST/ALT groupings on overall survival, and Log-rank test was used for comparison. Cox proportional risk model was used to explore the influencing factors of death in children with HLH.

There were statistically significant differences in gender, PICU admission, treatment methods, incidence of respiratory failure and shock among the 3 groups (P<0.05). Lactate dehydrogenase, creatine kinase isoenzyme, serum ferritin and activated partial thromboplastin time in the T3 group were higher than those in the T1 and T2 groups, while the levels of albumin and fibrinogen in the T3 group were lower than those in the T1 and T2 groups (P<0.05). Na⁺ level in the T2 and T3 groups was lower than that in the T1 group, while C-reactive protein level was higher than that in the T1 group (P<0.05). Correlation analysis showed that AST/ALT was positively correlated with absolute neutrophil count (r_s=0.182, P=0.040), C-reactive protein (r_s=0.419, P<0.001), total bilirubin (r_s=0.182, P=0.040), creatine kinase isoenzyme (r_s=0.310, P<0.001), lactate dehydrogenase (r_s=0.474, P<0.001), activated partial thromboplastin time (r_s=0.316, P<0.001), serum ferritin (r_s=0.311, P<0.001), and negatively correlated with albumin (r_s=-0.352, P<0.001), fibrinogen (r_s=-0.179, P=0.043), Ca²⁺ (r_s=-0.259, P=0.003), Na⁺ (r_s=-0.244, P=0.006). ROC curve results showed that the AUCs of C-reactive protein, lactate dehydrogenase, activated partial thromboplastin time, serum ferritin and fibrinogen were 0.560〔95%CI (0.451, 0.669) 〕, 0.666〔95%CI (0.560, 0.772) 〕, 0.605〔95%CI (0.499, 0.710) 〕, 0.724〔95%CI (0.626, 0.822) 〕, 0.648〔95%CI (0.551, 0.745) 〕 and 0.715〔95%CI (0.624, 0.807) 〕, respectively, with the optimal cutoff values of 82.08 mg/L, 40.5 U/L, 927.5 U/L, 53.95 s, 1 897 μg/L, and 1.45 g/L, respectively. The mortality rate in the T1, T2 and T3 groups was 14.0% (6/43), 33.3% (14/42) and 44.2% (19/43), respectively, with statistically significant differences (χ²=9.518, P=0.009). Multivariate Cox proportional hazard regression analysis showed that shock〔HR=4.24, 95%CI (2.09, 8.61), P<0.001〕, activated partial thromboplastin time ≥53.95 s〔HR=2.44, 95%CI (1.24, 4.81), P=0.010〕and serum ferritin ≥1 897 μg/L〔HR=3.05, 95%CI (1.02, 9.09), P=0.046〕were the risk factors for death in children.

HLH patients in children with higher AST/ALT have higher incidence of poor prognosis, shorter overall survival, and worse prognosis.