Epstein-Barr virus (EBV)-associated post-transplantation lymphoproliferative disorder simultaneously affecting both B and T cells after allogeneic bone marrow transplantation.

Post-transplantation lymphoproliferative disorder (PTLD) is usually an aberrant proliferation of EBV-infected B cells. We report the case of a 31-year-old man with severe aplastic anemia who suffered PTLD 42 days post-BMT from an unrelated donor. At the onset of PTLD, peripheral blood lymphocytes were comprised of 40% CD20(+) cells, 3% CD4(+) cells, and 56% CD8(+) cells. A highly sensitive in situ hybridization (ISH) method was used to detect EBV-encoded small non-polyadenylated RNA 1 (EBER-1) in 33.9% of sorted CD20(+) cells, 4.4% of CD4(+) cells, and 1.4% of CD8(+) cells. Each T-cell fraction contained less than 0.034% of contaminated EBV-infected B cells. Clonal proliferation of both B and T cells was demonstrated by Southern blotting. The patient did not respond to donor leukocyte infusion and died due to deterioration of PTLD. At autopsy, examination of multiple organs revealed B-cell (rather than T-cell) infiltration. This case clearly indicates that EBV can simultaneously infect B and T cells and can induce clonal proliferation of both lymphocyte subsets in severely immunocompromised patients.