Age-related factors in cyclosporine-induced syngeneic graft-versus-host disease: regulatory role of marrow-derived T lymphocytes

The Effect ofAge on the Induction of SGVHD Initial studies were undertaken to assess the effect of age on the induction of SGVHD in Lewis rats treated with C&A after syngeneic marrow transplants . Animals of 1, 3, or 6 mo of age were irradiated, reconstituted with marrow from similarly aged Marrow-derived T Lymphocytes in Syngeneic Graft-versus-Host Disease syngeneic donors, respectively, and treated with graded doses of CsA for 30 d. The results in Fig. 1 demonstrate a significant effect of age on the induction of SGVHD. 1-mo-old transplanted Lewis rats demonstrated a virtual 100% incidence of SGVHD when treated with 10 and 15 mg of CSA ; a 70% incidence was observed when the animals were treated with 5 mg/kg of this drug. In contrast, a moderate incidence (50%) of SGVHD was observed in animals that were transplanted at 3 mo of age, and only at the highest dose of CsA tested . A minimal incidence of SGVHD was observed in rats that were initially transplanted at 6 mo of age.