SOLUBLE FAS LEVELS IN SERA OF BONE-MARROW TRANSPLANTATION RECIPIENTS ARE INCREASED DURING ACUTE GRAFT-VERSUS-HOST DISEASE BUT NOT DURING INFECTIONS

Graft-versus-host disease (GVHD) and infections are two major complica tions of allogeneic bone marrow transplantation (BMT). In the course o f GVHD, one of the pathways that activated cytotoxic T cells use to ex ecute their killing mechanisms is the Fas/Fas ligand pathway. This kil ling mechanism might be accompanied by the release of soluble Fas (sFa s) in the circulation. To examine the association of serum sFas levels and post-BMT complications, we have analyzed sFas levels in sera of b one marrow recipients with and without GVHD. Postallogeneic BMT sFas l evels were significantly increased during clinically relevant acute GV HD (aGVHD; P = .002). However. during infections sFas levels tended to decrease (P = .088). Yet, the simultaneous occurrence of GVHD and inf ections resulted in extreme high spas levels. These results suggested that sFas release may be correlated with the amount of tissue damage, because aGVHD induces more damage than infections. The presence of sig nificantly increased spas levels during aGVHD provides new insights in to the GVHD pathogenesis. (C) 1998 by The American Society of Hematolo gy.