Unveiling the Molecular Mechanisms of Chronic Active Epstein-Barr Virus Infection

Researchers from Kyoto University have shed light on the molecular mechanisms underlying chronic active Epstein-Barr virus (EBV) infection, a heterogeneous and poorly understood disease characterized by the proliferation and infiltration of EBV-infected T/natural killer (NK) cells into multiple organs. By conducting a comprehensive multi-omics analysis of 65 CAEBV patients, the study identified two distinct subtypes of NK cell-type CAEBV based on the CpG island methylator phenotype (CIMP). The research also demonstrated that a hypomethylating agent, 5-Azacytidine, may be effective in treating high-risk CIMP-positive CAEBV.

Key Takeaways:

  • Chronic active EBV infection is characterized by the proliferation and infiltration of EBV-infected T/NK cells into multiple organs, resulting in diverse clinical courses.
  • The study identified two distinct subtypes of NK cell-type CAEBV based on the CpG island methylator phenotype (CIMP): CIMP-positive and CIMP-negative CAEBV.
  • CIMP-positive CAEBV had a poor prognosis, displayed a "neoplastic" phenotype, and exhibited a DNA methylation pattern similar to that of extranodal NK/T-cell lymphoma.
  • The study demonstrated that 5-Azacytidine, a hypomethylating agent, may be effective in treating high-risk CIMP-positive CAEBV.
  • The research also established a method to effectively detect EBV-infected cells in single-cell analysis, suggesting that EBV-infected NK cells have tissue-resident properties.
  • The study suggests that innate and adaptive immunity to EBV is compromised in patients with CAEBV.
  • The present findings provide insight into the complex molecular features of CAEBV and suggest potential molecular therapies.

Statistics:

  • 65 CAEBV patients were analyzed in this study.
  • The study identified two distinct subtypes of NK cell-type CAEBV based on the CpG island methylator phenotype (CIMP).
  • CIMP-positive CAEBV had a higher tumor mutation burden and frequent copy number alterations compared to CIMP-negative CAEBV.
  • 5-Azacytidine, a hypomethylating agent, was shown to be effective in treating high-risk CIMP-positive CAEBV in both in vitro and in vivo functional assays.
  • The study established a method to effectively detect EBV-infected cells in single-cell analysis.

Sources:

  • Multiomics analysis reveals the genetic and epigenetic features of high-risk NK cell-type chronic active EBV infection. Blood Journal, 2025.
  • NewsRx. Studies from Kyoto University Add New Findings in the Area of Epstein-Barr Virus (Multiomics analysis reveals the genetic and epigenetic features of high-risk NK cell-type chronic active EBV infection). Health & Medicine Week. August 22, 2025; p 7257.