[Is tacrolimus effective for ongoing renal allograft rejection?]

Tacrolimus has already gained a high reputation as an induction-maintenance immunosuppressive therapy after kidney transplantation. Recently, it is being used as rescue therapy against rejection, and its effectiveness also appears to have been established to some extent. In this study, we evaluated the efficacy of Tacrolimus rescue therapy at 4 institutions in the Kinki District. The subjects were 19 patients treated with Tacrolimus against rejection observed during immunosuppressive therapy using cyclosporin. Evaluation was made by classifying the patients into 6 with acute rejection that occurred within 3 months after transplantation (AR), 4 with late onset acute rejection that developed more than 3 months after operation (LAR), and 9 patients with chronic rejection (CR). In the AR group, many patients received combination therapy at the introduction of Tacrolimus, and the long-term outcome was satisfactory. Tacrolimus was effective in 2 (50%) of the 4 patients in the LAR group. The trough levels of Tacrolimus at its introduction were 10-15 ng/ml in the AR and LAR groups. Deterioration of the transplanted kidney function was prevented in 3 (50%) out of 6 patients in the CR group observed for less than 1 year, but it deteriorated in all 3 patients observed for 1 year or longer. The trough levels of tacrolimus at its introduction were 5-10 ng/ml in many patients in the CR group. The rescue therapy using Tacrolimus was effective against acute rejection but further follow-up is considered to be needed to evaluate its efficacy against chronic rejection.