Jay R. Bucci

The Impact of Transplantation with Deceased Donor Hepatitis C-Positive Kidneys on Survival in Wait-Listed Long-term Dialysis Patients

Whether transplantation of deceased donor kidney allografts from donors with antibodies against hepatitis C virus (HCV) confers a survival advantage compared with remaining on the kidney transplant waiting list is not yet known. We studied 38,270 USRDS Medicare beneficiaries awaiting kidney transplantation who presented with end‐stage renal disease from April 1, 1995 to July 31, 2000. Cox regression was used to compare the adjusted hazard ratios for death among recipients of kidneys from deceased donors, and donors with antibodies against hepatitis C (DHCV+), controlling for demographics and comorbidities. In comparison to staying on the waiting list, transplantation from DHCV+ was associated with improved survival among all patients (adjusted hazard ratio for death 0.76, 95% CI 0.60, 0.96). Of patients receiving DHCV+ kidneys, 52% were themselves hepatitis C antibody positive (HCV+), so outcomes associated with use of these grafts may have particular implications for HCV+ transplant candidates. Recommendations for use of DHCV+ kidneys may require analysis of data not currently collected from either dialysis or transplant patients. However, transplantation of DHCV+ kidneys is associated with improved patient survival compared to remaining wait‐listed and dialysis dependent.

Hepatitis C and Renal Transplantation in the Era of Modern Immunosuppression

Kidneys from donors who are positive for hepatitis C virus (DHCV+) have recently been identified as an independent risk factor for mortality after renal transplantation. However, it has not been determined whether risk persists after adjustment for baseline cardiac comorbidity or applies in the era of modern immunosuppression. Therefore, a historical cohort study was conducted of US adult cadaveric renal transplant recipients from January 1, 1996, to May 31, 2001; followed until October 31, 2001. A total of 36,956 patients had valid donor and recipient HCV serology. Cox regression analysis was used to model adjusted hazard ratios for mortality and graft loss, respectively, adjusted for other factors, including comorbid conditions from Center for Medicare and Medicaid Studies Form 2728 and previous dialysis access-related complications. It was found that DHCV+ was independently associated with an increased risk of mortality (adjusted hazard ratio, 2.12, 95% confidence interval, 1.72 to 2.87; P < 0.001), primarily as a result of infection. Mycophenolate mofetil was associated with improved survival in DHCV+ patients, primarily related to fewer infectious deaths. Adjusted analyses limited to recipients who were HCV+, HCV negative, or age 65 and over, or by use of mycophenolate mofetil confirmed that DHCV+ was independently associated with mortality in each subgroup. It is concluded that DHCV+ is independently associated with an increased risk of mortality after renal transplantation adjusted for baseline comorbid conditions in all subgroups. Recipients of DHCV+ organs should be considered at high risk for excessive immunosuppression.

Impact of Diabetes and Hepatitis after Kidney Transplantation on Patients Who Are Affected by Hepatitis C Virus

Complications associated with use of donor hepatitis C-positive kidneys (DHCV+) have been attributed primarily to posttransplantation liver disease (as a result of hepatitis C disease). The role of posttransplantation diabetes has not been explored in this setting. With the use of the United States Renal Data System database, 28,942 Medicare KT recipients were studied from January 1, 1996, through July 31, 2000. Cox proportional hazards regression models were used to calculate adjusted hazard ratios (AHR) for the association of sero-pairs for HCV (D+/R-, D+/R+, D-/R+ and D-/R-) with Medicare claims for de novo posttransplantation HCV and posttransplantation diabetes. The peak risk for posttransplantation HCV was in the first 6 mo after transplantation. The incidence of posttransplantation HCV after transplantation was 9.1% in D+/R-, 6.3% in D+/R+, 2.4% in D-/R+, and 0.2% in D-/R-. The incidence of posttransplantation diabetes after transplantation also peaked early and was 43.8% in D+/R-, 46.6% in D+/R+, 32.3% in D-/R+, and 25.4% in D-/R-. Associations for both complications were significant in adjusted analysis (Cox regression). Both posttransplantation HCV (AHR, 3.36; 95% confidence interval, 2.44 to 4.61) and posttransplantation diabetes (AHR, 1.81; 95% confidence interval, 1.54 to 2.11) were independently associated with an increased risk of death, but posttransplantation diabetes accounted for more years of life lost, particularly among recipients of DHCV+ kidneys. Posttransplantation diabetes may contribute substantially to the increased risk of death associated with use of DHCV+ kidneys and accounts for more years of life lost than posttransplantation HCV. Because HCV infection acquired after transplantation is so difficult to treat, methods that have been shown to reduce viral transmission warrant renewed attention.

Donor Hepatitis C Seropositivity: Clinical Correlates and Effect on Early Graft and Patient Survival in Adult Cadaveric Kidney Transplantation

The impact of hepatitis C virus-positive donor kidneys on patient survival has not been analyzed in a national study. This study analyzed 20,111 adult (age, > or =16 yr) recipients having solitary cadaveric kidney transplants from adult donors with valid donor hepatitis C serologies from July 1, 1994, to June 30, 1998, in an historical cohort study (the 2000 United States Kidney Data System) of patient survival. Analysis was by the Cox proportional hazards models, which corrected for characteristics thought to affect outcomes. Of 484 kidneys positive for hepatitis C virus serology, 165 (34%) were given to recipients with confirmed negative hepatitis C serologies. Unadjusted 3-yr patient survival was 93% in all recipients of donor hepatitis C-negative kidneys versus 85% in all recipients of donor hepatitis C-positive kidneys (P = 0.01). Among hepatitis C-positive recipients, those who received hepatitis C-positive kidneys had worse survival than recipients of hepatitis C-negative kidneys. Among elderly hepatitis C-negative recipients, those who received hepatitis C-positive kidneys also had worse survival; in fact, all recipients of donor hepatitis C-positive kidneys had increased risk of mortality (P = 0.028). There were no significant interactions between donor hepatitis C positivity and either recipient hepatitis C positivity or older recipient age. The use of hepatitis C-positive kidneys in recipients who were hepatitis C-negative was fairly common and contrary to some current recommendations. Recipients of donor hepatitis C-positive kidneys were at independently increased risk of mortality, with no evidence that any subgroups were less affected.

Graft Loss and Acute Coronary Syndromes after Renal Transplantation in the United States

The impact of graft loss on acute coronary syndromes (ACS) after renal transplantation has not been studied in a national population. It was hypothesized that ACS might be more frequent after graft loss, as many of the benefits of a functioning allograft on metabolism and volume regulation would be lost. Data from the 2000 United States Renal Data System (USRDS) was used to conduct an historical cohort study of ACS in 14,237 patients who received renal transplants between April 1, 1995, and June 30, 1998, (followed until April 28, 2000) with valid information from CMS Form 2728, excluding patients with hospitalized ACS before renal transplant. Cox nonproportional regression models were used to calculate the time-dependent adjusted hazard ratio (AHR) of graft loss (censored for death) for time-to-first hospitalization for ACS (International Classification of Diseases 9th Modification Diagnosis Codes [ICD9] code 410.x or 411.x) occurring after transplant. The incidence of ACS was 12.1 per 1000 patient-years (PY) in patients after graft loss versus 6.5 per 1000 PY after transplantation (excluding patients with graft loss). As a time-dependent variable, graft loss had an AHR of 2.54 (95% confidence interval, 1.09 to 5.96; P = 0.031 by Cox regression). Other risk factors associated with ACS included diabetes, older recipient, and male recipient. Allograft rejection was NS. Renal transplant recipients share some of the risk factors for ACS with the general population. In addition, graft loss was identified as a unique risk factor for ACS in this population.

Acute coronary syndromes after renal transplantation in patients with end-stage renal disease resulting from diabetes.

Coronary heart disease is the leading cause of death in both diabetes mellitus and end‐stage renal disease. Although renal transplantation is known to reduce mortality in end‐stage renal disease, its effect on the incidence of acute coronary syndromes is unknown. Using data from the United States Renal Data System, we studied 11 369 patients with end‐stage renal disease due to diabetes enrolled on the renal and renal‐pancreas transplant waiting list from 1 July 1994 to 30 June 1997. Cox nonproportional hazards regression models were used to calculate the adjusted, time‐dependent relative risk for the most recent hospitalization for acute coronary syndromes (including acute myocardial infarction, unstable angina, or other acute coronary syndromes, ICD9 Code 410.x or 411.x) for a given patient in the study period. Demographics and comorbidities were controlled by using data from the medical evidence form (HCFA 2728). After renal transplantation, patients had an incidence of acute coronary syndromes of 0.79% per patient year, compared to 1.67% per patient year prior to transplantation. In comparison to maintenance dialysis, renal transplantation was independently associated with a lower risk for acute coronary syndromes (hazard ratio 0.38, 95% confidence interval, 0.30–0.49). Patients with end‐stage renal disease due to diabetes on the renal transplant waiting list were much less likely to be hospitalized for acute coronary syndromes after renal transplantation. The reasons for this decreased risk should be the subject of further study.

Hospitalizations for total hip arthroplasty after renal transplantation in the United States.

The national incidence of and factors associated with total hip arthroplasty in renal transplant recipients has not been reported. We conducted an historical cohort study of 42 096 renal transplant recipients in the United States between 1 July 1994 and 30 June 1998. Primary outcomes were associations with hospitalizations for a primary discharge code of total hip arthroplasty (ICD9 procedure code 81.51x) within 3 years after renal transplant using Cox regression. Renal transplant recipients had a cumulative incidence of total hip arthroplasty of 5.1 episodes/1000 person‐years, which is 5–8 times higher than reported in the general population. Avascular necrosis of the hip was the most frequent primary diagnosis associated with total hip arthroplasty in this population (72% of cases). Repeat surgeries were performed in 27% of patients with avascular necrosis, vs. 15% with other diagnoses. Total hip arthroplasty was more frequent in transplant recipients who were older, African American, or who experienced allograft rejection. Mortality after total hip arthroplasty was 0.21% at 30 days and 15% at 3 years, similar to the mortality of all transplant recipients. The most common indication for total hip arthroplasty after renal transplant is avascular necrosis of the hip, in contrast to the general population. Although repeat surgeries are common, total hip arthroplasty is well tolerated and is not associated with increased mortality in this population.