Graft-versus-lymphoma effect after allogeneic peripheral blood stem cell transplantation for primary central nervous system lymphoma

Allogeneic peripheral blood stem cell transplantation (allo PBSCT) is a rec ognized treatment modality for hematological malignancies resistant to conv entional chemoradiotherapy. The post-transplant immune-mediated graft-versu s-leukemia effect has major curative potential. In this case presentation, the allogeneic approach to resistant recurrent primary central nervous syst em (CNS) lymphoma using peripheral blood stem cells from an HLA identical s ibling after immune-suppressive non-myeloablative conditioning, was examine d clinically. The patient in question had relapsing refractory primary CNS lymphoma and is the first to be treated with this modality. She developed e arly skin and liver-localized grade II graft-versus-host disease after allo PBSCT, which then responded to short-term treatment. Chimeric studies at t he time showed 100% donor cells and repeated magnetic resonance imaging of the brain revealed gradual shrinkage of the tumor. Three months after trans plant the cerebral mass was no longer evident and currently, 30 months afte r transplantation, the patient continues to be disease free. The absence of any signs of malignancy suggests the development of a durable graft-versus -lymphoma effect in this brain tumor and indicates that this effect may be achieved even after non-myeloablative conditioning.