Clinical value of assessing prednisolone pharmacokinetics before and after renal transplantation.

The value of assessing the kinetics of prednisolone for predicting graft survival and the occurrence of adverse effects of long-term treatment with prednisolone was evaluated in 35 renal transplant patients. The subjects were given an oral test dose of 30 mg prednisolone before, shortly after and 3 months after transplantation. Serum samples were assayed for prednisolone and endogenous hydrocortisone by a specific HPLC method. Intrinsic prednisolone clearance differed less than three-fold (range 0.10-0.27 l/kg X h) between the patients and was relatively stable at different times in each of them. From the data obtained it was not possible to predict rejection episodes. If rejection occurred, however, a high clearance (greater than or equal to 0.20 l/kg X h) appeared to be deleterious for the outcome (p less than 0.05). Patients with Cushingoid habitus did not differ from non-Cushingoid patients with respect to prednisolone clearance or endogenous hydrocortisone level. 7 out of 8 cases of steroid-related complications (steroid diabetes, psychosis, duodenal ulcer, perforation of the colon and osteonecrosis) occurred in patients with a clearance lower than 0.16 l/kg X h (ns). The one-year graft survival rate was 67% in patients with a clearance greater than or equal to 0.16 l/kg X h, compared to 85% in patients with a lower clearance (ns). Although some correlation may exist between prednisolone kinetics, graft survival and steroid-related complications (not statistically significant in the present study), the predictive value of prednisolone kinetics is probably small in routine clinical work.