Acute and chronic graft-versus-host disease in dogs given hemopoietic grafts from DLA-nonidentical littermates. Two distinct syndromes.

We recognized two distinct clinical and histologic syndromes of acute and chronic graft-versus-host disease (GVHD) in irradiation chimeric dogs given hemopoietic grafts from DLA-nonidentical littermate donors. Clinically acute GVHD developed, with a median onset of 13 days after the transplant, and was characterized by skin erythema, jaundice, diarrhea, and gram-negative infections; the median survival of these dogs was 29.5 days. Chronic GVHD developed a median of 124 days after the transplant and was characterized by generalized skin ulcerations, massive ascites, and gram-positive infections; the median survival of these dogs was 150 days. Chronic GVHD could be distinguished histologically from acute GVHD by epidermal atrophy and dermal fibrosis and by bile duct proliferation, bridging, piecemeal necrosis, and portal fibrosis in the liver. Questions related to GVHD in man can be investigated in this model of acute and chronic GVHD in a large outbred species.