Graft failure after T cell-depleted bone marrow transplantation: clinical and immunological characteristics and response to immunosuppressive therapy.

We have investigated the clinical and immunological features of 10 cases of graft failure after T cell-depleted marrow transplantation. In addition, the hypothesis that the process of graft failure can be reversed by immunosuppressive therapy with cyclosporin + steroids +/- monoclonal antibodies was tested in seven patients. Early graft failures (before day 50) presented a uniform clinical syndrome with a host T lymphocytosis preceding the loss of the graft. In the majority of cases of late graft failure (after day 50) a syndrome comprising delayed granulopoietic regeneration, fever of unknown origin and abdominal symptoms was observed. Surface marker analysis of peripheral blood and bone marrow lymphocytes implicated a population of CD3+, CD8+, DR+ host T lymphocytes with a frequent co-expression of the Leu7+ antigen in the pathogenesis of graft failure. Immunosuppressive therapy reversed graft failure in the three cases of incomplete graft failure (i.e. with residual reticulocytes) and failed in the four cases of complete graft failure (i.e. no residual reticulocytes).