Control of Epstein-Barr virus load and lymphoproliferative disease by maintenance of CD8+ T lymphocytes in the T lymphocyte-depleted graft after bone marrow transplantation.

Of 100 bone marrow transplant recipients, 30 (30%) received a CD4(+) lymphocyte-depleted graft (1x10(6) CD8(+) T lymphocytes/kg of body weight). Replication of Epstein-Barr virus (EBV) was observed in 40 patients (40%). The use of a CD4(+) lymphocyte-depleted graft was the only independent risk factor for replication of EBV (relative risk, 11.5; 95% confidence interval, 5.8-22.8; P<.0001). Nevertheless, EBV load in those patients was not higher than in the rest of patients, and the low EBV load prevented the development of lymphoproliferative disease. These results suggest that the presence of CD8(+) T lymphocytes in the bone marrow graft can control EBV load, thereby reducing the risk of developing lymphoproliferative disease.