Engraftment syndrome following hematopoietic stem cell transplantation.

During neutrophil recovery following hematopoietic stem cell transplantation, a constellation of symptoms and signs including fever, erythrodermatous skin rash, and noncardiogenic pulmonary edema often occur. These clinical findings have usually been referred to as engraftment syndrome, or, reflecting the manifestations of increased capillary permeability, capillary leak syndrome. While described most often following autologous stem cell transplantation, a similar clinical syndrome has been observed followed allogeneic stem cell transplantation. Distinction from graft-versus-host disease in the allogeneic setting however, has been difficult. Recent experience with non-myeloablative conditioning for stem cell transplantation, however, reveals that an engraftment syndrome independent of GVHD may occur. In some cases, this engraftment syndrome may be a manifestation of a host-versus-graft reaction (graft rejection). While cellular and cytokine interactions are believed to be responsible for these clinical findings, a distinct effector cell population and cytokine profile have not been defined. Engraftment syndromes are likely associated with an increased transplant-related mortality, mostly from pulmonary and associated multi-organ failure. Corticosteroid therapy is often dramatically effective for engraftment syndrome, particularly for the treatment of the pulmonary manifestations. A proposal for a more uniform definition of engraftment syndrome has been developed in order to allow for a reproducible method of reporting of this complication and for evaluating prophylactic and therapeutic strategies.