Allogenic stem cell transplant in a patient with classical Kaposi's sarcoma

A 68 year old male with a history of classical Kaposi's sarcoma (KS) and precursor T-cell acute lymphoblastic leukemia (ALL) received an allogenic stem cell transplant from an unrelated donor to treat his ALL. He developed acute graft-vs.-host-disease (GVHD) which was treated by increasing immunosuppressants. KS, which had been in remission for years, then recurred aggressively. Tapering immunosuppressants to treat the KS was not possible because of GVHD. Chemotherapy could not be used because of its adverse effect on the bone marrow so soon after transplant. The only option was to use antiviral therapy (cidofovir) to lower the level of HHV-8, the virus that is a causal factor in KS. Although HHV-8 levels were significantly reduced, new KS lesions continued to appear. The patient developed acute kidney injury after the third cidofovir infusion and died from renal and respiratory failure soon afterward. Post-mortem revealed extensive internal KS lesions involving multiple organs. Based on the experience with this patient, allogenic transplant using an unrelated donor has been found to be a questionable treatment modality for classical KS patients requiring treatment for another condition such as leukemias and lymphomas. Post-transplant immunosuppression is required to prevent GVHD, and if it occurs, immunosuppression may have to be increased. Aggressive KS developed in this patient under these conditions, and could not be controlled by tapering immunosuppressants. Although the risk of GVHD is lower for an allogenic transplant using a matched sibling instead of an unrelated donor, the risk of both GVHD and aggressive KS both developing may still be unacceptably high.Alternative treatment modalities for these patients might include continuing with chemotherapy and autologous transplant. These avoid GVHD and lower the need for long term immunosuppression, but have a much higher risk of relapse of the underlying malignancy. Still, they could be preferable to an allogenic transplant for such cases.