A decade of experience with renal transplantation in African-Americans

Abstract

OBJECTIVE To evaluate the strategies instituted by the authors' center to decrease the time to transplantation and increase the rate of transplantation for African-Americans, consisting of a formal education program concerning the benefits of living organ donation that is oriented to minorities; a laparoscopic living donation program; use of hepatitis C-positive donors in documented positive recipients; and encouraging vaccination for hepatitis B, allowing the use of hepatitis B core Ab-positive donors. SUMMARY BACKGROUND DATA The national shortage of suitable kidney donor organs has disproportional and adverse effects on African-Americans for several reasons. Type II diabetes mellitus and hypertension, major etiologic factors for end-stage renal disease, are more prevalent in African-Americans than in the general population. Once kidney failure has developed, African-Americans are disadvantaged for the following reasons: this patient cohort has longer median waiting times on the renal transplant list; African-Americans have higher rates of acute rejection, which affects long-term allograft survival; and once they are transplanted, the long-term graft survival rates are lower in this population than in other groups. METHODS From March 1990 to November 2001 the authors' center performed 2,167 renal transplants; 944 were in African-Americans (663 primary cadaver renal transplants and 253 primary Living donor renal transplants). The retransplants consisted of 83 cadaver transplants and 17 living donor transplants. Outcome measures of this retrospective analysis included median waiting time, graft and patient survival rates, and the rate of living donation in African-Americans and comparable non-African-Americans. Where applicable, data are compared to United Network for Organ Sharing national statistics. Statistical analysis employed appropriate SPSS applications. RESULTS One- and 5-year patient survival rates for living donor kidneys were 97.1% and 91.3% for non-African-Americans and 96.8% and 90.4% for African-Americans. One- and 5-year graft survival rates were 95.1% and 89.1% for non-African-Americans and 93.1% and 82.9% for African-Americans. One- and 4-year patient survival rates for cadaver donor kidneys were 91.4% and 78.7% for non-African-Americans and 92.4% and 80.2% for African-Americans. One- and 5-year graft survival rates for cadaver kidneys were 84.6% and 73.7% for non-African-Americans and 84.6% and 68.9% for African-Americans. One- and 5-year graft and patient survival rates were identical for recipients of hepatitis C virus-positive and anti-HBc positive donors, with the exception of a trend to late graft loss in the African-American hepatitis C virus group due to higher rates of noncompliance, an effect that disappears with censoring of graft loss from that cause. The cadaveric renal transplant median waiting time for non-African-Americans was 391 days compared to 734 days nationally; the waiting time for African-Americans was 647 days compared to 1,335 days nationally. When looking at all patients, living and cadaver donor, the median waiting times are 220 days for non-African-Americans and 462 days for African-Americans. CONCLUSIONS Programs specifically oriented to improve volunteerism in African-Americans have led to a marked improvement in overall waiting time and in rates of living donation in this patient group. The median waiting times to cadaveric renal transplantation were also significantly shorter in the authors' center, especially for African-American patients, by taking advantage of the higher rates of hepatitis C infection and encouraging hepatitis B vaccination. These policies can markedly improve end-stage renal disease care for African-Americans by halving the overall waiting time while still achieving comparable graft and patient survival rates.

Figure 1. Actuarial graft survival for all cadaveric renal transplants. One- and 5-year graft survival rates are 84.7% and 68.9% for African-Americans and 84.6% and 73.7% for non-African-Americans (P = .008).

Figure 2. Actuarial patient survival for all cadaveric renal transplants. One- and 5-year patient survival rates are 92.4% and 80.2% for African-Americans and 91.4% and 78.7% for non-African-Americans (P = .793).

Figure 3. Actuarial graft survival for all living donor renal transplants. One- and 5-year graft survival rates are 93.1% and 82.9% for African-Americans and 95.1% and 89.1% for non-African-Americans (P = .032).

Figure 4. Actuarial patient survival for all living donor renal transplants. One- and 5-year patient survival rates are 96.8% and 90.4% for African-Americans and 97.1% and 91.3% for non-African-Americans (P = .230).

Figure 5. Actuarial graft survival for all cadaveric renal transplants from donors positive for anti-HBc. One- and 5-year graft survival rates are 87% and 62% in African-Americans and 90% and 73% for non-African-Americans. There is no difference in the outcome for African-American and non-African-American patients (P = .762). The outcome of recipients of anti-HBc-positive and anti-HBc-negative kidneys is nearly identical at 5 years for non-African-American and African-American patients.

Figure 6. Five-year, non-compliance-censored, Kaplan-Meier graft survival rates for African-American (solid line) and non-African-American recipients of HCV-positive kidneys. At 5 years the graft survival rate among African-Americans was not different from that of non-African-Americans (63.5% vs. 74.3%, P = .98, log-rank).

Figure 7. Kaplan-Meier rates of living donor transplantation among African-American kidney registrants. The lowest rate was for group 1 patients (short dashes); these patients were registered before initiation of the live donor kidney transplant formal education program or laparoscopic live donor nephrectomy. The transplant rate was higher after introduction of the formal family education program (group 2, long dashes) (P = .10). The transplant rate after initiation of the laparoscopic donation technique (group 3, solid line) was similar to that after introduction of the formal education program, and higher than the transplant rate of group 1 patients (P = .008).

Figure 8. Actuarial graft survival in all African-American kidney transplant recipients in the mycophenolate mofetil era. Comparison of tacrolimus (FK)- and cyclosporin (CSA)-based immunosuppression. The combined living donor and cadaveric 1- and 5-year graft survival rates for African-Americans in the mycophenolate mofetil era were 89% and 79% with tacrolimus-based therapy and 85% and 60% with cyclosporine-based therapy (P = .006).

Figure 9. Cumulative rate of at least one rejection in all African-American kidney transplant recipients in the mycophenolate mofetil era. Comparison of tacrolimus (FK)- and cyclosporin (CSA)-based immunosuppression. At 1 year the rate in African-American patients was 36% with cyclosporine-based therapy but only 9% with tacrolimus-based therapy (P < .0001).