Nomogram-based prediction of post-splenectomy thrombocytosis in children with hereditary spherocytosis

BACKGROUND Hereditary spherocytosis (HS) is the most common congenital hemolytic anemia in children, and splenectomy remains the standard treatment. However, postoperative thrombocytosis (PST) frequently occurs and may predispose patients to thromboembolic events. Despite its clinical relevance, the risk factors contributing to PST in children with HS remain inadequately defined, and reliable predictive tools are lacking. We hypothesized that specific clinical and hematological parameters could be integrated into a nomogram model to predict the occurrence of PST and thereby improve perioperative risk stratification and individualized management. AIM To identify risk factors for PST in children with HS after splenectomy and develop a predictive nomogram model. METHODS We retrospectively analyzed 230 children with HS who underwent total splenectomy at Anhui Provincial Children’s Hospital (2018 to 2025). Patients were classified into PST (n = 158) and normal platelet (n = 72) groups. Clinical features and preoperative hematological indices were collected, and postoperative platelet counts were monitored on days 6-10. Univariate and multivariate logistic regression identified independent predictors. A nomogram was constructed, and its discrimination, calibration, and clinical utility were evaluated using receiver operating characteristic curve, calibration curve, and decision curve analysis. RESULTS Among 230 patients, 158 (68.7%) developed PST. Univariate analysis showed associations with preoperative hemoglobin < 90 g/L (P = 0.03), reticulocyte > 6% (P = 0.001), total bilirubin > 34 μmol/L (P = 0.04), preoperative platelet count < 150 × 109/L (P = 0.02), and transfusion ≥ 10 mL/kg (P = 0.01). Multivariate regression identified reticulocyte > 6% [odds ratios (OR) = 2.46, 95% confidence interval (CI): 1.35-4.48, P = 0.003], preoperative platelet count < 150 × 109/L (OR = 1.95, 95%CI: 1.12-3.39, P = 0.02), and transfusion ≥ 10 mL/kg (OR = 1.88, 95%CI: 1.09-3.24, P = 0.02) as independent predictors. The nomogram achieved an area under the curve of 0.92 (95%CI: 0.87-0.96), with good calibration and clinical net benefit across thresholds of 0.2-0.7. CONCLUSION PST is frequent after splenectomy in pediatric HS. The nomogram integrating reticulocyte percentage, platelet count, and transfusion volume provides an accurate and clinically useful tool for risk prediction and individualized perioperative management.