Autoimmune thrombocytopenic purpura after autologous stem cell transplantation.

The pathogenesis of thrombocytopenia occurring after autologous stem cell transplantation (ASCT) remains unclear. Six cases of classical peripheral thrombocytopenia that developed after ASCT for non-Hodgkin's lymphoma (NHL) are presented. Resolution of this complication was obtained by usual treatment such as steroids, splenectomy or progressively resolved without specific treatment. Five out of six patients have been followed for more than 5 years after hematopoietic transplantation and are still alive in complete remission despite poor prognostic factors at diagnosis. Several arguments suggest that this phenomenon represents autoimmune thrombocytopenia and may be the consequence of an altered immune balance. Consequently, development of autoimmune reactions after bone marrow transplantation might be associated with an antitumoral effect (graft-versus-lymphoma effect).