Determination of Epstein-Barr Virus–Infected Lymphocyte Cell Types in Peripheral Blood Mononuclear Cells as a Valuable Diagnostic Tool in Hematological Diseases

BACKGROUND: High loads of Epstein-Barr virus (EBV) in peripheral blood mononuclear cells (PBMCs) can be indicative of a broad spectrum of diseases, ranging from asymptomatic infection to fatal cancers. METHODS: We retrospectively investigated the EBV-infected cell types in PBMCs among 291 patients. Based on EBV-infected cell types, the clinical features and prognoses of 93 patients with EBV-associated (EBV(+)) T/natural killer (NK)–cell lymphoproliferative diseases (LPDs) T/NK-LPDs) were investigated over a 5-year period. RESULTS: Although B-cell-type infection was found in immunocompromised patients and patients with asymptomatic high EBV carriage, infectious mononucleosis, EBV(+) B-cell LPDs and B-cell lymphomas, T-cell, NK-cell or multiple-cell-type infection in immunocompetent hosts were highly suggestive of EBV(+) T/NK-LPDs, EBV(+) T/NK-cell lymphomas, and aggressive NK-cell leukemia. Patients with non–B-cell infection had a poorer prognosis than those with B-cell-type infection. In our cohort, 79.6% of patients with EBV(+) T/NK-LPDs were >18 years old, and NK cells were identified as EBV-infected cell type in 54.8%. Nearly half of patients with EBV(+) T/NK-LPDs had genetic defects associated with immunodeficiency. However, hemophagocytic lymphohistiocytosis, and not genetic defects, was the only parameter correlated with poor prognosis of EBV(+) T/NK-LPDs. CONCLUSIONS: Determination of EBV-infected cell types among PBMCs is a valuable tool for the differential diagnosis of EBV(+) hematological diseases. In this study, determination of Epstein-Barr virus-infected cell types in peripheral blood mononuclear cells of 291 patients with high Epstein-Barr virus loads were retrospectively investigated, which indicate it is a valuable tool for Epstein-Barr virus-associated hematological diseases.