Lymphoproliferative disorders developing after transplantation and their relation to simian T-cell leukemia virus...

In this report the role of the HTLV-1-like simian T-cell leukemia virus (STLV) during the development of posttransplantation lymphoproliferative disorders (PTLPD) is described. To prevent rejection of an allogeneic transplant in 12 rhesus monkeys cyclosporin A (CyA), prednisone, and/or lymphocyte-specific monoclonal antibodies were used for immunosuppression. Seven monkeys died during the experiment between 22 and 179 days postoperatively. At autopsy in 4 monkeys PTLPD were found. In each case, STLV provirus was acquired during the experiment, either from the blood transfusions or allograft donors. Seroconversion of anti-STLV titers occurred in 3 monkeys. However, Southern blot analysis showed the presence of STLV provirus at the DNA level in all PTLP tissues. PTLPD morphology and phenotype varied significantly. In conclusion, for the first time the oncogenic potential of STLV is identified in a rhesus monkey transplantation model. Moreover, the importance of screening blood and organ donors for HTLV-1 must be emphasized.