In 2006, approximately 50,000 hematopoietic cell transplants (HCT) were performed worldwide, and about 20,000 were allogeneic transplants. Indeed, the number of allogeneic transplants performed has demonstrated an exponential increase through the 1980s and 1990s. While offering cure for many diseases, the success of allogeneic transplantation is limited by complications. One of the most significant complications associated with considerable morbidity and mortality is chronic graft versus host disease (cGVHD). The focus of this chapter will be on the incidence and trends in cGVHD over the last three decades since its first recognition in the mid-1970s.
In the 1980s, the Seattle group reported the remarkable success of HCT in achieving long-term survival without disease recurrence in patients with hematologic malignancies. Among the long-term survivors, 60% to 75% were leading normal lives and, in particular, had no evidence of GVHD. However, between 25% and 40% of long-term survivors developed cGVHD. The Seattle group summarized the clinical manifestations of cGVHD in 20 patients who were transplanted between 1969 and 1976. Manifestations were similar to collagen vascular diseases and included debilitating skin sclerosis, generalized sicca syndrome, severe oral and esophageal mucositis, malabsorption, pulmonary insufficiency, chronic liver disease, recurrent bacterial infections, and generalized wasting.