Pathophysiology and Immunology of Chronic Graft-Versus-Host Disease

Abstract

Chronic graft-versus-host disease (cGVHD) is the leading cause of late morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplant (HSCT) [1, 2].Chronic GVHD and its associated complications result in increased resource utilization, poor quality of life parameters, and decreased overall survival in patients. Early detection and appropriate intervention will help in improving long-term outcomes of HCT patients. Detection of biomarkers in blood or involved tissue (skin, gut, etc.) may help in early diagnosis and risk-stratification of patients, thereby impacting the type and intensity of immunosuppressive therapy chosen. To date, early intervention and successful treatment of cGVHD patients has lagged due to difficulty in scoring organ involvement due to lack of uniform and objective scoring tools. Another major problem in the field is the absence of approved therapies in the steroid refractory setting, which is a result of the difficulties of clinical trials in this patient population due to poor standardization of scoring systems and evaluation of objective responses. There are other competing causes of death, including disease relapse and infectious complications that may confound survival data. Establishment of standardized cGVHD scoring systems has helped enormously in staging the disease and evaluating responses to new therapies, thereby helping to make objective response evaluations possible [3].