Early Risk Factors and Clinical Characteristics of Pediatric Hemophagocytic Lymphohistiocytosis: A Single-Center Retrospective Study

Background: Hemophagocytic lymphohistiocytosis (HLH) is a severe hyperinflammatory syndrome in children with rapid disease progression and high mortality. Early identification of clinical characteristics and risk-related indicators is essential for timely diagnosis and intervention. Objective: To investigate early clinical characteristics and potential early risk-related factors associated with pediatric HLH among children with suspected HLH. Methods: We retrospectively collected clinical data from 205 children with suspected HLH who met the inclusion criteria at the Xinjiang Uygur Autonomous Region Children’s Hospital between July 2021 and February 2026. Univariate logistic regression, variance inflation factor (VIF) assessment, and LASSO–logistic regression were used to examine clinical variables associated with HLH and to retain potential early risk-related factors. The performance of the final LASSO–logistic regression model was further evaluated using the area under the receiver operating characteristic curve (AUC), calibration curves, bootstrap resampling for internal validation, and the Hosmer–Lemeshow test. Results: Of the 205 patients, 56 (27.3%) were diagnosed with HLH. LASSO–logistic regression identified fever duration (OR = 1.551, 95% CI: 0.973– 2.472), serum ferritin (SF) (OR = 1.019, 95% CI: 1.001– 1.039), triglycerides (TG) (OR = 1.424, 95% CI: 1.003– 2.022), fibrinogen (FIB) (OR = 0.832, 95% CI: 0.663– 1.044), and D-dimer (D-D) (OR = 1.014, 95% CI: 0.990– 1.038) as potential early risk-related factors associated with HLH. The combined model showed the highest discriminative ability, with an AUC of 0.748. The Hosmer–Lemeshow test indicated good calibration (P = 0.721), and bootstrap internal validation yielded a C-index of 0.722. Conclusion: Fever duration, SF, D-D, FIB, and TG were potential early risk-related factors associated with pediatric HLH and may provide clinically useful information for early risk assessment in children with suspected HLH.