Mortality and Kidney Transplantation Outcomes Among Hepatitis C Virus-Seropositive Maintenance Dialysis Patients: A Retrospective Cohort Study

Abstract

Rationale & objective: Hepatitis C virus (HCV) infection is common among maintenance dialysis patients. Few studies have examined both dialysis survival and transplantation outcomes for HCV-seropositive patients because registry data sets lack information for HCV serostatus.

Study design: Retrospective cohort study.

Setting & participants: Adult long-term dialysis patients treated by a US national dialysis provider between January 1, 2004, and December 31, 2014.

Exposure: HCV antibody serostatus obtained as part of clinical data from a national dialysis provider.

Outcomes: Mortality on dialysis therapy, entry onto the kidney transplant waiting list, kidney transplantation, and estimated survival benefit from kidney transplantation versus remaining on the waitlist.

Analytical approach: After linking clinical data with data from the Organ Procurement and Transplantation Network, Cox and cause-specific hazards regression were implemented to estimate the associations between HCV seropositivity and mortality, as well as entry onto the kidney transplant waitlist. Cox regression was also used to estimate the survival benefit from transplantation versus dialysis among HCV-seropositive individuals.

Results: Among 442,171 dialysis patients, 31,624 (7.2%) were HCV seropositive. HCV seropositivity was associated with a small elevation in the rate of death (adjusted HR [aHR], 1.09; 95% CI, 1.07-1.11) and a substantially lower rate of entry onto the kidney transplant waitlist (subdistribution HR [sHR], 0.67; 95% CI, 0.61-0.74). Once wait-listed, the kidney transplantation rate was not different for HCV-seropositive (sHR 1.10; 95% CI, 0.96-1.27) versus HCV-seronegative patients. HCV-seropositive patients lived longer with transplantation (aHR at 3 years, 0.42; 95% CI, 0.27-0.63). Receiving an HCV-seropositive donor kidney provided a survival advantage at the 2-year posttransplantation time point compared to remaining on dialysis therapy waiting for an HCV-negative kidney.

Limitations: No data for HCV viral load or liver biopsy.

Conclusions: HCV-seropositive patients experience reduced access to the kidney transplantation waitlist despite deriving a substantial survival benefit from transplantation. HCV-seropositive patients should consider foregoing HCV treatment while accepting kidneys from HCV-infected donors to facilitate transplantation and prolong survival.

Trial registration: ClinicalTrials.gov NCT02743897.

Keywords: Dialysis; ESRD modality; HCV seropositive; barriers to transplantation; chronic kidney disease (CKD); delisting; end-stage renal disease (ESRD); hepatitis C virus (HCV); kidney transplantation; survival benefit; waitlisting.

Figure 1a and 1b.

Cumulative incidence of a) waitlisting and b) transplantation, treating death as a competing risk in each case.

Figure 2a and 2b.

Hazard ratio for death among HCV-seropositive candidates associated with a) kidney transplantation compared to remaining on the waiting list, b) kidney transplantation with a HCV-seropositive kidney compared to the strategy of remaining on the waitlist and/or accepting a HCV-negative kidney* * Models were time updated for transplantation and included age, gender, race, diabetes, cardiovascular disease, severe liver disease, insurance, income, panel reactive antibody, dialysis vintage, prior kidney transplant, body mass index, dialysis modality, year of waitlisting interacted with time, hemoglobin, platelets, and albumin.