Cyclosporine and methylprednisolone after allogeneic marrow transplantation: association between low cyclosporine concentration and risk of acute graft-versus-host disease.

A combination of cyclosporine (CSA) and methylprednisolone (MP) was used as graft-versus-host disease (GVHD) prophylaxis in 25 patients age 11-47 years (median 27 years) who received HLA-compatible sibling marrow transplants after myeloablative therapy for leukemia, myelodysplasia or lymphoma. CSA was initiated at 3 mg/kg/day in two divided doses, and the dose was adjusted to maintain a trough whole blood h.p.l.c. concentration between 200 and 800 ng/ml. While on i.v. CSA, the dose of CSA was increased for 10 of the 25 patients. The actuarial rate of grades II-IV acute GVHD was 37%. Those patients who developed moderate to severe GVHD had a significantly higher early mortality than those who did not (56% vs 12%, p = 0.02). There was a significant association between the development of acute GVHD and a mean week 2 CSA trough concentration less than 250 ng/ml. Life threatening regimen-related toxicities in the first 100 days included capillary leak syndrome, acute pancreatitis and small bowel perforation. Although the combination of CSA and MP in this dosing schedule was active in preventing acute GVHD, nephrotoxicity remained a problem, and outcome was limited by the inability to achieve the target CSA trough concentration in a substantial proportion of patients.