Epstein‐barr virus‐positive recipient type B‐cells survive in a “complete chimera” after allogeneic bone‐marrow transplantation

Abstract

Yao et al., 1985a) or of survival of low numbers of infected B cells (Yao et al., 198%). Lymphoproliferative tumors do not usually carry EBV genomes (Andiman et al., 1983) but a few cases of EBV-positive lymphoma have been described following BMT (Schubach et al., 1985). These were monoclonal (Schubach et al., 1982), but polyclonal tumors have been described as well and all were of donor origin whenever this point was investigated (Martin et al., 1984). This, together with the observation that EBV-specific cytotoxic T cells re-emerge relatively early after allogeneic BMT (Crawford et a l . , 1986) argues against long-term persistence of infected B cells in vivo.Allogeneic BMT offers an opportunity to study this problem since either sex differences between donor and recipient or genetic polymorphism of cellular isoenzymes such as AcP or PGM-1 make it possible, in most cases, to determine whether the cells in BMT patients are of donor or recipient origin (Mittermuller et a l . , 1986). More than 90% of European adults have been infected with EBV (Yao et al., 1985~). It is an open question whether EBV-immortalized B-cell clones of the recipient persist or whether they are eliminated either by BMT conditioning or by immunological mechanisms. We report findings which suggest that EBV-transformed clones of recipient origin can indeed persist after BMT even if the patient has become a "complete chimera" according to the most sensitive criteria that are presently available. PatientA 43-year-old woman presented with severe tricytopenia following nitrefazol (anti-obesity drug) complicated by bleed- Post-grafting immunosuppression consisted of Cyclosporin A i.v. 5 mg/kg body weight for 5 days followed by 3 mg/kg until day 34 and subsequently orally until day 250 (9 months). No steroids were given at any time. At the time of writing, she is in full clinical remission (40 months). Cell preparationThe patient's bone marrow cells were aspirated with preservative-free heparin after informed consent had been obtained. For culture and cytogenetic studies the cells were centrifuged over Ficoll (density 1,077 g/l). For enzyme analyses the erythrocytes were sedimented and the leukocyte-rich buffy coat was further processed. Polymorphonuclear cells were isolated from the pellet of Ficoll separations by lysis of the contaminating erythrocytes with ammonium chloride. Thrombocytes were recovered from the upper layers of the buffy coat after mild sedimentation. T cells and monocytes were isolated in the pellet of Ficoll-gradients by a direct immune-rosetting technique (Wilhelm et al., 1986) using erythrocytes coated with pan-T-antibodies (CD2, Rieber et al., 1986) or with antimonocyte antibodies. T-depleted lymphocytes were recovered from the interface. Morphological studiesSmears were prepared by standard methods employing MayGriinwald-Giernsa stain, periodic acid Schiff reaction and myeloperoxidase. Immunological phenotypingSurface markers were identified with an enzyme-immunoassay on poly-1-lysine coated adhesive slides (Morich et al...

The Physiologic Reservoir of Epstein‐Barr Virus Does Not Map to Upper Aerodigestive Tissues

“…A large number of studies suggested the B lymphocyte as the most likely site of EBV persistence (as well as primary infection), 13‐16 consistent with the high density of EBV receptors (CD 21) and virus‐triggered transformation pathways in these cells 17‐21 . Other studies, however, suggest that mucosal epithelium in oropharyngeal or other sites 22‐24 may be the target of primary EBV infection and the site of EBV persistence.…”