Introduction: In recent years, the use of higher risk donor organs and steroid avoidance regimens with potential increased acute rejection risk have increased. We hypothesized that these patterns adversely affect changes in posttransplant renal function.
Methods: By using Scientific Registry of Transplant Recipients data and multivariable generalized linear models, we examined factors associated with slopes of estimated glomerular filtration rate (GFR; modification of diet in renal disease) from 6 to 12 months and 6 to 24 months posttransplant in solitary adult renal transplant recipients transplanted between 2003 and 2008 (n=91,241). We estimated GFR at each interval, analyzed changes within patients between follow-up intervals, and evaluated changes in 1-year graft and patient survival during the study period.
Results: GFR intercept at 6 months averaged 54.3 mL/min/1.73 m² (standard deviation [SD] 18.2 mL/min/1.73 m²). Decline in GFR between 6 and 12 months posttransplant averaged 0.69 mL/min/1.73 m² (SD 10.9 mL/min/1.73 m²) and between 6 and 24 months averaged 2.45 mL/min/1.73 m² (SD 15.7 mL/min/1.73 m²). However, the GFR decline was significantly attenuated during the study period among both deceased and living donor transplant recipients. Factors significantly associated with steeper GFR decline were increased pretransplant dialysis time, older donor age, diabetes as a primary diagnosis, low body mass index, African American race, retransplants, nonprivate insurance, and increased panel reactive antibody percent. Baseline or slope in renal function did not differ substantially by immunosuppressive regimen. One-year overall graft survival increased during the study period from 92.3% to 93.9%.
Conclusions: GFR slopes and 1-year survival rates have improved in the United States independent of donor quality and immunosuppressive regimen. Findings may reflect increased skill in medical management and need further evaluation to determine whether short-term improvements translate to improved long-term survival.