Graft-versus-host disease in two immunocompetent dogs.

Graft-versus-host disease developed in two dogs injected with lymphocytes from BCG immunized donors. The disease was characterized by bone marrow depression, ulcerative enteritis, necrotizing cholangiohepatitis, thymic atrophy, pancreatitis, lymphadenopathy, inflammation of mucous membranes and weight loss. In one of the two dogs repopulation of bone marrow and lymphoid tissue by donor cells was demonstrated by cytogenetics. The development of GVHD was considered unusual because both animals received on immunosuppressive treatment and both responded well to PHA in lymphocyte transformation assays indicating they were immunocompetent. It was hypothesized that stimulation of donor lymphocytes by BCG enhanced their ability to induce a graft-versus-host reaction.