Although the most effective way to prevent GVHD is T cell depletion, this process results in poor immune function leading to increased rates of relapse, graft rejection, and post-transplant infections. Through selective depletion of alloreactive donor lymphocytes, we hope to reduce mortality from GVHD, while preserving the efficacy of the transplant. To test the effect of selective depletion we have only altered the T cell component of the transplant.
Patients receive a low intensity preparative regimen consisting of cyclophosphamide and fludarabine.
The unadsorbed fraction, remaining after the positive CD34 selection, is then co-cultured for 72 hours with irradiated lymphocytes from the patient. Following the preparative regimen, the patient receives successive infusions of the stem cell product and selected lymphocytes. All patients receive standard post transplant immunosuppression with cyclosporine for a minimum of 30 days, followed by dose reduction depending on the degree of donor lymphocyte chimerism. Stopping rules will minimize the risk of untoward or unexpected side effects. Life expectancy must be greater than 3 months.