Identification of clinical and histopathologic risk factors for diminished renal function 2 years posttransplant

The aim of this study was to identify early clinical and pathologic variates that independently predict diminished renal allograft function at 24 mo posttransplant. A clinical pathologic data base was prospectively derived from 71 patients in whom protocol renal biopsies were performed at 1, 2, 3, 6, and 12 mo posttransplant. The major end point was the 24-mo serum creatinine. Variates correlating independently (r2 = 0.67) with the 24-mo serum creatinine were the chronic biopsy scores (months 3 and 6), late rejections (months 4 to 6), cyclosporin A (CsA) levels (months 1 to 2), and delayed graft function. The adjusted odds ratio (OR) and 95% confidence interval (CI) for having a serum creatinine > or = 130 mumol/L at 24 mo increased for every year the donor age increased (OR = 1.07; 95% CI, 1.02 to 1.13; range, 9 to 55) or for each late rejection episode (OR = 5.9; 95% CI, 1.7 to 20.1), whereas a mean CsA level > 300 micrograms/L from months 1 to 3 was protective (OR = 0.07; 95% CI, 0.01 to 0.43). Variates correlating independently (r2 = 0.53) with the change in serum creatinine from 6 to 24 mo (delta Cr6-24) were the chronic biopsy scores at months 3 and 6. The adjusted OR of the delta Cr6-24 rising > or = +20 mumol/L increased for every year the donor age increased (OR = 1.09; 95% CI, 1.02 to 1.16; range 9 to 56) or when the 6-mo chronic biopsy score was > or = 2 (OR = 6.6; 95% CI, 1.2 to 36.4). An estimate of the relative risk for diminished renal function at 2 yr can be assigned within 6 mo of transplant based on chronic pathology, late acute rejections, CsA levels, and donor age.