Epstein-Barr Virus in the Bone Marrow of Patients with Aplastic Anemia

STUDY OBJECTIVE: To determine whether Epstein-Barr virus is present in the bone marrow of patients with aplastic anemia. DESIGN: Assay of fresh and fixed bone marrow specimens for Epstein-Barr virus using immunofluorescence for nuclear antigen, Southern analysis with an Epstein-Barr virus specific probe, and in-situ hybridization. SETTING: Governmental medical referral center. PATIENTS: Five patients were studied prospectively: three who previously had infectious mononucleosis, one with a recent viral pneumonitis, and one who was asymptomatic. Stored DNA samples from other patients with aplastic anemia were also screened. MEASUREMENTS AND MAIN RESULTS: Epstein-Barr virus DNA and protein were detected in the bone marrow of 5 patients studied prospectively and in 1 of 40 patients studied retrospectively. As estimated by in-situ hybridization, about 3% to 5% of marrow cells were infected with virus in those patients who had not received acyclovir. In contrast, Epstein-Barr virus DNA was not detected in peripheral blood DNA of these patients, nor were Epstein-Barr virus proteins or DNA found in the bone marrow of normal donors, patients with other hematologic diseases, or in 1 patient with acute infectious mononucleosis. Analysis of DNA fragments by hybridization with Epstein-Barr virus probes showed a pattern dissimilar to the type of Epstein-Barr virus usually associated with infectious mononucleosis. CONCLUSIONS: Aplastic anemia may be associated with Epstein-Barr virus more commonly than suspected by history. Localization of the virus in the bone marrow supports a causative role for Epstein-Barr virus in bone marrow failure.