Clinical features and prognostic model for viral encephalitis after allogeneic haematopoietic stem cell transplantation

Summary The objective of this study was to identify independent prognostic factors of viral encephalitis (VE) after allogeneic haematopoietic stem cell transplantation (allo‐HSCT) and establish a prognostic model to identify post‐transplant VE patients with a greater likelihood of mortality. Among 5380 patients in our centre from 2014 to 2022, 211 patients who developed VE after allo‐HSCT were reviewed in this retrospective study. Prognostic factors were selected, and a prognostic model was constructed using Cox regression analysis. The model was subsequently validated and estimated using the area under the receiver operating characteristic curve (AUC), a calibration plot and decision curve analysis (DCA). Glasgow Coma Scale score <9, lesions >3 lobes on magnetic resonance imaging and severe thrombocytopenia were identified as independent prognostic risk factors for VE patients who underwent allo‐HSCT. The prognostic model GTM (GTM is an abbreviation for a model composed of three risk factors: GCS score <9, severe thrombocytopenia [platelet count <20 000 per microliter], and lesions >3 lobes on MRI) was established according to the regression coefficients. The validated internal AUC was 0.862 (95% confidence interval [CI], 0.773–0.950), and the external AUC was 0.815 (95% CI, 0.708–0.922), indicating strong discriminatory ability. Furthermore, we constructed calibration plots that demonstrated good consistency between the predicted outcomes and the observed outcomes. DCA exhibited high accuracy in this system, leading to potential benefits for patients.