Chronic Graft-Versus-Host Disease

Overview

Chronic GVHD occurs in about 50% of all long-term survivors after allogeneic marrow or peripheral blood stem cell transplantation, and despite aggressive treatment, some 20%-40% of affected patients will succumb to GVHD and related complications. There is some suggestion that patients after blood stem cell transplantation experience more chronic GVHD. Chronic GVHD typically develops 3 months or later post-transplant, although histological and clinical manifestations may be present earlier. Conversely, in some patients, particularly after unrelated donor transplants, symptoms reminiscent of acute GVHD (i.e. rash, diarrhea) may occur at even after 3 months, and GVHD may be difficult to classify. Chronic GVHD generally differs from acute GVHD in its distribution of target organs (Table 24). T-lymphocytes which initiate acute GVHD are also believed to be involved in the pathogenesis of chronic GVHD. Since thymus function in transplant recipients can be diminished as a consequence of chemo/radiotherapy or acute GVHD, the lack of thymus function may account for to a certain extent for these immune imbalances.