CONTRIBUTION OF NATIVE KIDNEY-FUNCTION TO TOTAL GLOMERULAR-FILTRATIONRATE AFTER COMBINED KIDNEY-PANCREAS TRANSPLANTATION

Background Combined kidney-pancreas transplantation (CKPT) with its as sociated euglycemia has been shown to prevent or reduce recurrent diab etic nephropathy in the renal allograft, There has been no evaluation of residual native kidney function after CKPT. The purpose of this stu dy was to determine whether native kidney function may be present in d iabetic recipients years after CKPT, Methods, Between 1986 and 1992, 3 7 patients with type 1 insulin-dependent diabetes mellitus with renal failure underwent CKPT, In each case, a single native nephrectomy was performed, We studied 16 patients who had continuing renal and pancrea s function more than 4 years after CI(PT, Fourteen diabetics with a fu nctioning renal allograft but no pancreas function were used as a cont rol group, Simultaneous renal scans (technetium-99m diethylenetriamine pentaacetic acid) of the native and transplanted kidneys were obtaine d with a dual-head scintillation camera, Total glomerular filtration r ate (GFR) was determined from the rate of clearance of the tracer from the extracellular space measured for 2 hr with an ambulatory renal mo nitor, Results, The study groups had similar pretransplant characteris tics. At the time of the study, the mean serum creatinine level was no t significantly different in the CKPT and control groups (1.7+/-0.7 vs , 1.5+/-0.3 mg/dl, respectively), In the CKPT and control groups, tota l GFRs were 70.1+/-33 vs, 72.1+/-16.5 ml/min (NS), allograft GFRs were 63+/-34.2 vs, 70.4+/-16 ml/min (NS), and native kidney GFRs were 7.1/-7.2 vs, 1.7+/-1.9 ml/min (P<0.05), respectively, In both groups, the re was a significant correlation between total GFR and allograft GFR ( P<0.001), but not between total GFR and native kidney GFR, Significant single native kidney GFR (more than 8 ml/min) was found in 7/16 (44%) patients in the CKPT group, but in none of the controls. Conclusions, These results suggest that residual native kidney function can be pre sent and contribute moderately to total GFR after CKPT, Euglycemia aft er CKPT may have a protective role in native kidneys.