Role of splenectomy in incidence and severity of acute graft-versus-host disease: a multicenter study of 157 patients.

Allogeneic bone marrow transplantation is a therapeutic option for many hematological malignancies. Graft-versus-host disease (GVHD) remains one of the major complications and has a high mortality rate. The pathophysiological mechanisms involved are poorly understood and GVHD prevention regimens still give disappointing results. This study concerned 157 patients with diverse diagnoses from Bordeaux, Grenoble and Marseille who had undergone an HLA-matched transplantation without T cell depletion. Thirty-one patients (20%) had been splenectomized before transplantation. The role of splenectomy in the incidence and severity of acute GVHD was investigated using a univariate and multivariate analysis of 11 risk factors including splenectomy. Univariate analysis found three significant risk factors linked with GVHD incidence: splenectomy, age of recipient and GVHD prevention by monotherapy versus a combination of methotrexate plus cyclosporin. Multivariate analysis retained only the effects of age and GVHD prevention on GVHD incidence and showed that splenectomy was the most important factor in GVHD severity. One explanation for the role of splenectomy could be the spleen's possible function as a filter of activated T lymphocytes from the transplant. We therefore concluded that it would be preferable to abstain from splenectomizing patients before transplantation although splenectomy is still advisable in certain malignancies after transplantation.