Japanese study of kidney transplantation: 1. Results of early phase II study.

For a 4-month period from July to October 1990, 37 primary renal transplant patients were enrolled in the early phase II study of FK 506. An i.v. dose of FK 506 0.075 mg/kg twice a day was administered initially, and then in oral dose of 0.15 mg/kg twice a day followed. Prednisolone was started at 1 mg/kg daily as an additioned drug. Some 32 live related donors with one-mismatched haplotype of HLA and 5 cadaveric donors underwent transplantation. All patients are alive, and all kidney allografts are functioning. A correlation between the trough level of FK 506 in whole blood and acute rejection or adverse events was retrospectively investigated. There was a significant correlation between the trough level in whole blood and acute rejection or renal impairment. In conclusion, the therapeutic dose of FK 506 should be adjusted by monitoring the trough level in whole blood, the range of which might be recommended to be 15-20 ng/ml during the early phase after transplantation.