Chronic graft-versus-host disease after reduced-intensity stem cell transplantation versus conventional hematopoietic stem cell transplantation

Chronic graft-versus-host disease (GVHD) in children

Five-year survival rates for childhood cancer now exceed 80% and with the significant progress made by the transplant community in developing less toxic conditioning regimens and in the treatment of posttransplant complications, allo-hematopoietic stem cell transplantation (HSCT) contributes significantly to that population of long-term survivors. In this context, the acute and long-term toxicities of chronic graft-versus-host disease (cGVHD) have an ever-increasing effect on organ function, quality of life, and survival; patients and families who initially felt great relief to be cured from the primary disease, now face the challenge of a chronic debilitating illness for which preventative and treatment strategies are suboptimal. Hence, the development of novel strategies that reduce and or control cGVHD, preserve graft-versus-tumor effects, facilitate engraftment and immune reconstitution, and enhance survival after allo-HSCT represents one of the most significant challenges facing physician-scientists and patients.

Chronic graft-versus-host disease in the era of reduced-intensity conditioning

In the past decade the field of hematopoietic stem cell transplantation has entered a new era with the introduction of reduced intensity conditioning (RIC) regimens. The impact of RIC on the incidence of chronic graft-versus-host disease (GVHD) has not been evaluated systematically. Factors confounding such analyses include short follow-up in studies, absence of prospective comparison trials, use of a variety of RIC regimens, lack of uniform GVHD prophylaxis and lack of rigorous criteria for the diagnosis and staging of chronic GVHD. This review discusses factors that appear to influence the incidence and clinical presentation of chronic GVHD in the RIC transplantation era. Overall, RIC seems to decrease the incidence and severity of acute GVHD through day 100 post-transplant when compared to conventional conditioning; however, there is little evidence to suggest that chronic GVHD is reduced after RIC. For the more definitive assessments of chronic GVHD after RIC it will be important to study this question in prospective comparison trials with long duration of follow-up. The recent National Institutes of Health chronic GVHD consensus project recommendations provide now the critically needed standardized guidelines for the diagnosis, classification and staging of chronic GVHD.

Chronic graft versus host disease

PURPOSE OF REVIEW

Chronic graft versus host disease is a debilitating and often fatal complication of allogeneic stem cell transplantation. The purpose of this review is to overview this disease and highlight recent findings in the literature over the past year.

RECENT FINDINGS

A new focus on chronic graft versus host disease as a long-term complication of transplantation has resulted in increased research activity in this disease. Here we review the recent in-vitro and clinical studies that focus on the pathophysiology of the disease, treatment and prevention.

SUMMARY

As more patients undergo and survive allogeneic stem cell transplantation more attention is being focused on the study of chronic graft versus host disease. Although the pathophysiology is still controversial, recent advances have been made in our understanding of this disease, including the balance of T helper type 1 and 2 cells, the role of B cells and autoantibodies, graft manipulation and prophylaxis, which may lead to advances in treatment and prevention. The series of recent publications put forward by the National Institutes of Health consensus project on criteria for clinical trials are expected to advance the standards and uniformity of chronic graft versus host disease clinical research.