Impact of cyclosporine-A concentration on the incidence of severe acute graft-versus-host disease after allogeneic stem cell transplantation.

This single-center retrospective study analyzed 85 consecutive patients who underwent allogeneic stem cell transplantation (allo-SCT) with the aim to assess whether there is a correlation between exposure to cyclosporine-A (CsA; as measured by CsA concentrations during the first month after allo-SCT) and the risk for developing severe grade III-IV acute graft-versus-host disease (aGVHD). The median concentrations of CsA in the blood at 1, 2, 3, and 4 weeks after allo-SCT were 348 (range: 172-733), 284 (range: 137-535), 274 (range: 107-649), and 247 (range: 37-695) ng/mL, respectively. Overall, grade II-IV aGVHD occurred in 36 patients (42%) at a median of 29 (range: 6-100) days after allo-SCT.