Clinical features and risk factors for Epstein-Barr virus-associated encephalitis: a retrospective cohort study

Background Epstein-Barr virus (EBV) has been gradually recognized as an important pathogen of encephalitis, but our knowledge of EBV-associated encephalitis is still limited. The aim of this study was to describe the clinical features and explore the risk factors for EBV-associated encephalitis in a large cohort of Chinese patients. Methods All patients with confirmed encephalitis in our center from June 2020 to April 2021 were enrolled. Data were extracted from the electronic medical record system and analyzed by Student's t test, Mann-Whitney U test, chi-square test, and logistic regression analyses. Results This study included a total of 364 patients diagnosed with encephalitis, among which 86 cases (23.6%) had EBV detected in their cerebrospinal fluid (CSF), and 39 cases were diagnosed with EBV-associated encephalitis. The clinical characteristics of EBV-associated encephalitis differ from those caused by other herpes viruses. Compared to other herpes virus-related encephalitis, patients with EBV encephalitis exhibited significantly higher protein levels (1.310 [0.695, 1.840] vs. 0.710 [0.490, 1.700], p  < 0.001), lower glucose levels (3.030 [2.585, 3.640] vs. 3.380 [2.990, 4.030], p  < 0.001), and a higher incidence of meningeal involvement on MRI (11 (30.6%) vs. 3 (6.5%), p  = 0.010). Additionally, univariate logistic regression analysis revealed that age (OR = 1.015, 95% CI: 1.002–1.029), HIV infection (OR = 4.285, 95% CI: 1.582–11.816), non-tumor immunosuppression (OR = 5.713, 95% CI: 1.588–22.883), and peripheral blood EBV infection (OR = 10.204, 95% CI: 4.231–26.346) were independent risk factors for CNS EBV infection. Conclusion Compared to other herpes virus-associated encephalitis, EBV encephalitis is characterized by a higher degree of meningeal involvement, elevated CSF protein levels, lower glucose levels, and a reduced T-lymphocyte count in peripheral blood. These characteristics suggest that EBV encephalitis may have a distinct pathophysiology.