Hepatitis C virus genotype does not affect patient survival among renal transplant candidates

Abstract

Patients with end-stage renal disease (ESRD) are at increased risk for infection with different hepatitis C virus (HCV) genotypes and multiple genotype infections. However, to date, the effect of the type and number of infecting HCV genotypes on survival among ESRD patients has not been carefully examined, and this was the objective of this study. Sera from patients on the renal transplant waiting list at the New England Organ Bank between November 1986 and June 1990 were tested for anti-HCV using a third-generation enzyme-linked immunosorbent assay. All anti-HCV-positive serum samples were tested for HCV RNA by reverse transcriptase "nested" polymerase chain reaction (PCR) with primers derived from the highly conserved 5'UTR region of the HCV genome. HCV genotypes were determined by restriction fragment length polymorphism of the 5'UTR PCR product. The duration of follow-up was calculated from the date of the first available serum specimen until death, loss to follow-up, or December 31, 1995, whichever occurred earlier. Two separate multivariate models were constructed: one to examine the impact of HCV genotype on mortality and the other to examine the impact of the single versus mixed infection on mortality. In both models, the independent variables were HCV genotype and transplantation. The HCV genotype was treated as a time-independent (baseline) variable. Transplantation was treated as a time-dependent variable in which the status changed after transplantation. HCV RNA was detected by PCR in 224 patients (81%) in whom sera were available. Complete clinical data on baseline covariates, subsequent transplantation, and mortality were available in 180 patients (80%), and these patients constituted the final study cohort. HCV genotypes 1a and 1b were the two most common genotypes encountered and were found in 60 and 24% of the patients, respectively. One hundred and sixty-two (90%) patients were infected with a single HCV single genotype, 16 patients (9%) with two genotypes, and two patients (1%) with three genotypes. Among the 180 patients in the final study cohort, 86 (48%) underwent transplantation, and 66 (37%) patients died during follow-up. Compared with patients infected with HCV genotype 1a, the relative risk (RR) of death from all causes was not significantly increased among patients infected with genotype 1b (RR = 1.02, 95% CI, 0.55 to 1.89) or other genotypes (RR = 1.08, 95% CI, 0.50 to 2.30). Likewise, compared with patients with a single infection, the RR of death among patients with mixed infection (RR = 1.18, 95% CI, 0.52 to 2.66) was not significantly increased. The results of this study suggest that the type and number of HCV genotypes may not have a significant impact on survival among ESRD patients.