Long-term deterioration of kidney allograft function

Although long-term survival after kidney transplantation is critically dependent on maintaining stable allograft function, few studies have examined renal allograft function over time. Using pooled data from 10 278 consecutive transplants at five centers, we calculated slopes of estimated glomerular filtration rates (eGFR) measured after 1, 6 and 12 months in 9515, 8861 and 7359 patients surviving ≥1, ≥6 and ≥12 months, respectively. Slopes of eGFR progressively diminished for patients transplanted during 1984-1989, 1990-1993,1994-1998 and 1999-2002 (analysis of variance p < 0.0001 and p = 0.1245 for slopes measured after 1 and 6 months, respectively). Slopes measured after 12 months were less in the most recent era: -2.2 ± 7.2 mL/min/1.73 m²/year, -2.3 ± 6.6 mL/min/1.73 m²/year, -2.4 ± 7.4 mL/min/1.73 m²/year and -1.4 ± 10.9 mL/min/1.73 m²/year, respectively, p = 0.0058. Slopes measured after 1, 6 and 12 months each were less for transplantations during 1999-2002, after adjusting for multiple transplantation characteristics (p < 0.0001). Similarly, in Cox proportional hazards analysis, the risk (95% CI) for a 25% reduction in eGFR was 0.92 (0.85-1.01), p = 0.0736 during 1990-1994; 0.94 (0.82-1.08), p = 0.4111 during 1995-1998 and 0.78 (0.64-0.95), p = 0.0110 during 1999-2002 (compared to 1984-1989). We conclude that the rate of decline in allograft function after kidney transplantation has improved, suggesting that stable, long-term function may be achievable.