Objective monitoring of graft-versus-host disease: alpha 1-antichymotrypsin concentration changes after bone marrow transplantation in patients developing graft-versus-host reactions.

The levels of alpha 1-antichymotrypsin (ACT) was monitored in patients who underwent bone marrow transplantation. Seven received HLA-identical sibling bone marrow grafts, two received transplants from twins and one was given HLA-nonidentical marrow from his father. A dramatic increase of ACT was observed in all patients who developed graft-versus-host disease (GvHD). ACT did not rise at all in the case of patients who received marrow from twins, even in a patient who was given three transplants from the same donor. The patient transplanted from his father died from GvHD and the increase of ACT was the greatest fluctuation measured.