Hyperfiltration Affecting the Outcome of Living-related Renal Allograft

Park, Jong Ha; Kim, Yoo Mi; Park, Jung Sik; Kim, Ji Hoon; Chang, Sang Pil; Jung, Hae Hyuk; Lee, Mi Sook; Han, Deok Jong

Abstract

It is well known that immunologic factors like rejection episode and HLA missmatch influence allograft loss and prognosis. However, non-immu- nologic factors such as glomerular hyperfiltration may also have an effect on the survival of the allograft. We measured relative kidney function(dkRF) by DMSA scan, GFR(dGFR) using EDTA and CCr dCCr) by 24-hour urine collection in donors of 70 adult living-related renal allografts engrafted at a single center between December 1992 and January 1994 as a donor work-up before transplantation, and calculated donated kidney GFR(dkGFR=dGFRxdkRF) and CCr(dkCCr=dkCCrxdkRF). We observed graft function for 5 years and analyzed the prognostic factors for the graft. Graft dysfunction was defined as the increase of serum creatinine 5 years after transplantation more than 1.5 times of stabilized serum creatinine at 3 months after transplantation. 1) Sixty patients were followed up for 5 years. Graft dysfunction was observed in 22 patients(37%) and maintenance renal replacement therapy was required in 9(15%) of them. 2) Of the non-immunologic factors, donor age was older in patients with graft dysfunction(51 +/- 12 years) than those without it(34 +/- 11 years, p<0.01), but dkGFR(54.1 +/- 12.2ml/min vs. 58.5 +/- 11.9mVmin), dkCCr(44.8 +/- 14.3mVmin vs. 50.74 13.4ml/min) and the ratio of body surface area(recipient/donor, 0.964 0.14 vs. 0.990.12) were not different in the two groups. Age of recipients and occurrence of graft glomerulopathy also were not different in the two groups. The episode of acute rejection was more frequent in patients with graft dysfunction(32%, 7/ 22) than those without it(3%, 1/38, p<0.01), but the degree of HLA missmatch was not different. In multivariate analysis, donor age(p<0.01) and the episode of acute rejection(p<0.05) were independent factors affecting graft dysfunction. 3) Donor age was older(52 +/- 12 vs. 3814 years, p<0.01) and the episode of acute rejection was more frequent(56%, 5/9 vs. 696, 3/51, p<0.01) in 9 patients with graft loss than those without it. However, dkGFR, dkCCr, body surface area ratio, recipient age, occurrence of glomerulopathy and HLA missmatch were not different. In multivariate analysis, donor age(p<0.05) and the experience of acute rejection(p<0.01) were independent factors affecting graft loss. We therefore conclude that donor age is more important as non-immunologic prognostic factors in graft dysfunction than GFR of the donated kidney and the difference in body mass between recipient and donor.