Treatment of Established Human Graft-Versus-Host Disease by Antithymocyte Globulin

Forty successful marrow grafts have been carried out since April 1972 for the treatment of severe refractory aplastic anemia or acute leukemia. All patients were HL-A identical and nonreactive in mixed leukocyte culture tests with the marrow donor. Nineteen of the patients developed moderately severe to severe graft-versus-host disease (GVHD) and were treated with rabbit or goat antihuman antithymocyte globulin (ATG). Under ATG therapy, 12 of the 19 showed complete resolution of GVHD, five showed improvement of most organ systems involved, and two showed no change except for improvement in skin lesions. Six of the 19 became long-term survivors. Five of the six are alive between 276 and 629 days after grafting, and one died on day 346 with chronic respiratory failure. Of the remaining 13 patients, 11 died with interstitial pneumonitis of predominantly viral etiology, and two died with fungal and bacterial infections. In conclusion, the present study demonstrates the relative effectiveness of ATG in reversing human GVHD. Death with interstitial pneumonitis was the single most serious impediment to successful treatment of GVHD by ATG.