Stability of renal transplant function with alternate-day corticosteroid therapy.

Fifty-three renal transplant recipients with good to excellent renal function, while receiving daily maintenance or near-maintenance doses of azathioprine and methylprednisolone, were gradually converted to alternate-day corticosteroid therapy. Stability of allograft glomerular filtration rate (GFR) in each patient was assessed by calculating the slope of a plot of the reciprocal of the serum creatinine concentration vs time. After conversion to alternate-day therapy, GFR was stable in 80% but deteriorated in 20% of patients. However, most of the patients who experienced deteriorating GFR during alternate-day therapy regained stable renal function when given the same total corticosteroid dose but on a daily basis. This suggests but does not prove that maintenance-level daily corticosteroid therapy is better than maintenance-level alternate-day therapy in stabilizing allograft function. We conclude that maintenance-level alternate-day corticosteroid therapy should be used cautiously until a long-term prospective study determines whether there is an increased risk of losing renal function with this schedule and whether this potential risk is offset by reduced corticosteroid toxicity.