NK-cell post-transplant lymphoproliferative disease with chronic active Epstein-Barr virus infection-like clinical findings.

Abstract

A 69-year-old man who had underwent cord blood transplantation seven years ago was admitted because of fever, elevated liver enzymes and thrombocytopenia. Bone marrow aspirate revealed hemophagocytic lymphohistiocytosis. Viral capsid antigen (VCA)-immunoglobulin (Ig) G, VCA-IgM, VCA-IgA, Epstein-Barr virus nuclear antigen-IgG, early antigen-diffuse-type and restricted-type (EA-DR) IgG, and EA-DR IgA titers were 2560, <10, 10, 40, 40, and <10, respectively. Real-time polymerase chain reaction assay of peripheral whole blood for Epstein-Barr virus- deoxyribonucleic acid (EBV-DNA) revealed 240,000 copies/µg DNA. Flow cytometric in situ hybridization assay confirmed that EBV-infected cells were NK-cells. Clonality evaluation by Southern blot assay of EBV-DNA terminal repeats proved to be bi-clonal. Accordingly, we made a diagnosis of NK-cell post-transplant lymphoproliferative disease with chronic active EBV infection-like clinical findings (CAEBV-like NK-cell PTLD). Although CAEBV-like PTLD is extremely rare, its prognosis seems to be very poor. The disease should be considered in such patients who present persistent or recurrent infectious mononucleosis-like symptoms after transplantation.