CYCLOSPORINE MONITORING - IMPROVES GRAFT-VERSUS-HOST DISEASE PROPHYLAXIS AFTER BONE-MARROW TRANSPLANTATION

OBJECTIVE: The principal objective of this study was to determine whether a relationship exists between trough cyclosporine concentrations measured by HPLC and the development of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation. DESIGN: A retrospective analysis of 59 consecutive human Leukocyte antigen-matched bone marrow transplants. Patients received uniform GVHD prophylaxis with cyclosporine and methotrexate. Whole blood trough cyclosporine concentrations were measured at least twice weekly during hospitalization and weekly after discharge. SETTING: A dedicated bone marrow transplant unit in an academic center. MAIN OUTCOME MEASURES: The means of cyclosporine concentrations were assessed for each patient on a weekly basis during the first 50 days after transplant. These means were compared between patients developing grade 2-4 acute GVHD and patients without significant GVHD. RESULTS: Eighteen patients developed acute GVHD at a median of 25 days after bone marrow transplant (range 10-50). There was no correlation between the development of GVHD and patient age, diagnosis, donor age, donor gender, donor-recipient gender mismatch, and time to neutrophil engraftment (>1000 x 10(6) cells/L). Although mean weekly cyclosporine concentrations were consistently lower in patients developing acute GVHD, the difference in values compared with those of patients with GVHD was not statistically significant. Mean weekly cyclosporine concentrations at the time of neutrophil engraftment were statistically associated with the development of GVHD. Patients with GVHD had mean +/- SD concentrations of 174 +/- 69 ng/mL, significantly lower than 254 +/- 114 ng/mL in patients without GVHD. Furthermore, the rate of GVHD was 82 percent in patients with mean concentrations <200 ng/mL at the time of neutrophil engraftment as compared with a rate of 34 percent in patients with concentrations greater than or equal to 200 ng/mL (relative risk = 2.4). Also, mean cyclosporine concentrations measured during the week of onset of GVHD were significantly lower compared with mean cyclosporine concentrations of all other patients at risk of GVHD during that week.