Impaired kidney allograft: how long can it function? A single-center study of the transplantation population.

Impaired renal graft function is a matter of particular concern during post-transplantation care because low estimated glomerular filtration rate (eGFR) is a risk factor for graft loss. The aim of the study was to assess risk factors for inferior outcomes of kidney transplantations with low eGFRs. We identified 72 patients who underwent transplantation between 1999 and 2005 who had chronic renal graft dysfunction after 6 months post-transplantation (eGFR < 40 mL/min/1.73 m(2)), received a kidney transplant between 1999 and 2005, and were treated in one center through the entire post-transplantation course. Three patients who were lost for follow up after 6.4, 6.7, and 8.5 years are not included in this analysis. A group of 23 patients (33%) had chronic kidney disease stage 4 (eGFR < 30 mL/min/1.73 m(2)) at 6 months. In 39 patients (56%), delayed graft function was diagnosed. Forty-eight patients (70%) had at least one episode of acute graft rejection. Results were confirmed using biopsy in 39 patients. Eight patients (12%) died and 35 patients (51%) lost their grafts between 1.6 and 14 years (median, 6.3 years). The remaining 26 (38%) patients have still functioning allografts 11 years after transplantation (median). The initial immunosuppression included calcineurin inhibitor (CNI) in all cases. At the end of study, 6 (8.3%) patients received mammalian target of rapamycin inhibitor plus steroids, whereas the remaining were treated with CNIs. Improvement of kidney function by 15% was observed in 23% of the studied population between 6 and 24 months. This satisfactory outcome was a result of the careful follow-up examinations and comprehensive medical care provided by our dedicated staff of nurses and physicians. Improvement of kidney function may reflect a state of immune quiescence in some patients which allows them to sustain a functioning kidney despite injury.