Immunologic, clinical, and pathologic aspects of human graft-versus-host disease.

The three necessary factors in the development of graft-versus-host disease are the histoincompatibility of the host and the effector cells of this process, the immunoincompetence of the host, and the capability of effector cells to proliferate and attack host tissues protractedly in vivo. The disease may affect the alimentary tract, liver, bronchopulmonary tree, bone marrow, reticuloendothelial system, vascular endothelial cells, or epidermis. Graft-versus-host disease is potentially reversible or controllable if prompt, aggressive therapy is instituted. The recommended treatment is a combination of methotrexate, high-dose prednisone, and antithymocyte globulin.