Hepatitis C virus infection in renal transplant recipients: epidemiology, clinical impact, serological confirmation and viral replication

Hepatitis C in non-hepatic solid organ transplant candidates and recipients: A new horizon

Hepatitis C virus (HCV) infection is estimated to affect 130-150 million people globally which corresponds to 2%-3% of the total world population. It remains the leading indication for liver transplant worldwide and has been demonstrated to negatively impact both patient and graft survival following non-hepatic organ transplantation. In the era of interferon-based therapy, although treatment and cure of HCV prior to non-hepatic transplant improved survival, tolerability and low cure rates substantially limited therapy. Interferon (IFN)-based therapy following non-hepatic solid organ transplant, due to the risk of allograft rejection, is generally contraindicated. Rapid advances in IFN-free therapy with direct acting antivirals (DAAs) in the last few years have completely changed the paradigm of hepatitis C therapy. Compared to IFN-based regimens, DAAs have less frequent and less severe adverse effects, shorter durations of therapy, and higher cure rates that are minimally impacted by historically negative predictors of response such as cirrhosis, ethnicity, and post-transplant state. Recent studies have shown that liver transplant (LT) recipients can be safely and effectively treated with DAA combination therapies; although data are limited, many of the principles of therapy in LT may be extrapolated to non-hepatic solid organ transplant recipients. Here we review the data on DAA combination therapies in transplantation, discuss the advantages and disadvantages of pre- vs post-transplant HCV therapy and future directions.

Hepatitis C virus infection in end-stage renal disease and kidney transplantation

Liver disease secondary to chronic hepatitis C virus (HCV) infection is an important cause of morbidity and mortality in patients with end-stage renal disease (ESRD) on renal replacement therapy and after kidney transplantation (KT). Hemodialytic treatment (HD) for ESRD constitutes a risk factor for bloodborne infections because of prolonged vascular access and the potential for exposure to infected patients and contaminated equipment. Evaluation of HCV-positive/ESRD and HCV-positive/KT patients is warranted to determine the stage of disease and the appropriateness of antiviral therapy, despite such treatment is challenging especially due to tolerability issues. Antiviral treatment with interferon (IFN) is contraindicated after transplantation due to the risk of rejection, and therefore, treatment is recommended before KT. Newer treatment strategies of direct-acting antiviral agents in combination are revolutionizing HCV therapy, as a result of encouraging outcomes streaming from recent studies which report increased sustained viral response, low or no resistance, and good safety profiles, including preservation of renal function. KT has been demonstrated to yield better outcomes with respect to remaining on HD although survival after KT is penalized by the presence of HCV infection with respect to HCV-negative transplant recipients. Therefore, an appropriate, comprehensive, easily applicable set of clinical practice management guidelines is necessary in both ESRD and KT patients with HCV infection and HCV-related liver disease.

Prevalence and incidence of hepatitis C virus in hemodialysis patients in British Columbia: Follow-up after a possible breach in hemodialysis machines

BACKGROUND

A possible breach of the transducer protector in specific dialysis machines was reported in June 2004 in British Columbia (BC), which led to testing of hemodialysis patients for hepatitis C virus (HCV), hepatitis B virus (HBV) and HIV. This testing provided an opportunity to examine HCV incidence, prevalence and coinfection with HBV and HIV, and to compare anti-HCV and HCV polymerase chain reaction (PCR).

METHODS

The results of hemodialysis patients who were dialyzed on the implicated machines (65% of BC dialysis patients), and tested for HCV, HBV and HIV, between June 1, 2004, and December 31, 2004, were reviewed and compared with available previous results.

RESULTS

Of 1286 hemodialysis patients with anti-HCV and/or HCV-PCR testing, 69 (5.4%) tested positive. Two HCV genotype 4 seroconversions were identified. HCV incidence rate on dialysis was 78.8 cases per 100,000 person-years. Younger age, history of renal transplant and past HBV infection were associated with HCV infection. No occult infection was identified using HCV-PCR.

INTERPRETATION

Hemodialysis patients had three times the HCV prevalence rate of the general BC population, and more than 20 times the incident rate of the general Canadian population. One of the two seroconversions occurred before the testing campaign; the patient was likely infected during hemodialysis in South Asia. The other was plausibly a late seroconversion following renal transplant in South Asia. Nosocomial transmission cannot be ruled out because both patients were dialyzed in the same centre. Baseline and annual anti-HCV testing is recommended. HCV-PCR should be considered at baseline for persons with HCV risk factors, and for returning travellers who received dialysis in HCV-endemic countries to identify HCV infection occurring outside the hemodialysis unit.

Hepatitis C virus infection in haemodialysis and kidney transplant patients

Chronic infection with hepatitis C virus (HCV) is an important global health problem. The prevalence of HCV is significantly higher in haemodialysis and kidney transplant patients, as compared to the general population. In spite of the relatively milder liver disease activity reported in HCV-infected haemodialysis patients, HCV infection adversely affects survival. Likewise, HCV has a detrimental effect on both patient and graft survival after kidney transplantation. However, patient survival is significantly better with kidney transplantation compared to remaining on dialysis; therefore, HCV infection alone should not be a contraindication to transplantation. Combination antiviral therapy with pegylated interferon-alpha and low-dose ribavirin is currently evolving in haemodialysis patients. Interferon-alpha (standard/pegylated) is relatively contraindicated after kidney transplantation because of an increased risk of allograft rejection. Therefore, antiviral treatment of transplant candidates while on dialysis remains the best option and may avoid the risk of HCV-associated liver and renal disease after transplantation. Large multi-centre clinical trials are required in HCV-infected haemodialysis and kidney transplant patients in order to define optimal therapeutic strategies before and after transplantation.

Challenges and Controversies in the Management of Hepatitis C Virus Infection (Part 2)

Patients with HCV-related cirrhosis are frequently seen in clinical practice when the diagnosis is established either clini-cally when signs of chronic liver disease are evident, or histo-logically when liver biopsy is performed as part of the assess-ment of patients with HCV infection. It continues to be debat-able whether cirrhotic patients should receive antiviral therapy. Those who propose treatment state that eradication of HCV is the main goal of antiviral therapy thus limiting the spread of HCV infection and stress that cirrhosis is not a permanent in-jury that cannot be reversed. Opponents of antiviral therapy in patients with cirrhosis state that such treatment produces very low virological response rates in the face of a reportedly high incidence of side effects.

Should patients with chronic hepatitis C infection be transplanted?

Chronic hepatitis C (HCV) infection affects more than 170 million people throughout the world and 2 to 3 million Americans. End-stage liver disease secondary to chronic HCV infection is the most frequent indication for liver transplantation in this country. Currently, the gold standard for treatment for immunocompetent patients is a combination of peginterferon (PEG-IFN) and ribavirin for 6 to 12 months depending on the genotype. This treatment achieves a sustained virological response (SVR) in 54% to 61% of patients overall. Almost 50% of patients do not respond or have recurrences posttreatment and progress in over 10 to 20 years into chronic liver disease and its complications. Liver transplantation is the only therapeutic modality that impacts on quality of life and survival of these patients. However, recurrence of HCV in the new allograft is universal with accelerated progression to cirrhosis in 5 to 10 years. Response to treatment is usually low (20% to 30%), and associated with significant side effects and depression. A significant percentage of patients with recurrent HCV after transplantation require retransplantation to control the complications of end-stage liver disease. Other solid organ transplants recipients already HCV-positive, or infected at the time of transplantation from blood transfusions or an infected graft, develop accelerated, progressive liver disease facilitated by the adverse effects of immunosuppression in addition to HCV replication. To prevent morbidity, mortality, and high costs related to the consequences of HCV infection, all solid organ transplant candidates should be tested for HCV infection and treated appropriately with PEG-IFN and ribavirin prior to transplantation.

Treatment of Hepatitis C in Solid Organ Transplantation

Hepatitis C virus (HCV) infection is highly prevalent worldwide, and results in significant morbidity and mortality. HCV frequently infects haemodialysis patients and appears to impact on long-term survival of kidney transplant recipients. Therefore, treatment is recommended for kidney transplant candidates before transplantation and should be avoided following transplantation because of a high risk of allograft rejection. HCV infection does not appear to influence survival in cardiac transplant recipients and cardiac transplant recipients should also not be treated. In general, HCV-infected patients with cirrhosis are not considered as candidates for either kidney or cardiac transplantation given their risk of decompensation. HCV is the most common indication for liver transplantation and re-infection with varying degrees of liver injury is universal. Survival after liver transplantation is reduced among HCV-infected patients when compared with uninfected controls. Therefore, treatment using interferon and ribavirin is advocated; however, such therapy is frequently limited by adverse effects. Thus, improved antiviral treatment modalities are eagerly awaited in the transplant setting.

Management of chronic viral hepatitis before and after renal transplantation

Hepatitis C virus (HCV) infection is present in 2-50% of renal transplant recipients and patients receiving hemodialysis. Renal transplantation confers an overall survival benefit in HCV positive (HCV+) hemodialysis patients, with similar 5-year patient and graft survival to those without HCV infection. However, longer-term studies have reported increased liver-related mortality in HCV-infected recipients. Unfortunately, attempts to eradicate HCV infection before transplant have been disappointing. Interferon is poorly tolerated in-patients with end-stage renal disease and ribavirin is contraindicated because reduced renal clearance results in severe hemolysis. Antiviral therapy following renal transplantation is also poorly tolerated, because of interferon-induced rejection and graft loss. Although the prevalence of hepatitis B virus (HBV) infection has declined in hemodialysis patients and renal transplant recipients since the introduction of routine vaccination and other infection control measures, it remains high within countries with endemic HBV infection (especially Asia-Pacific and Africa). Renal transplantation is associated with reduced survival in HBsAg+ hemodialysis patients. Unlike interferon, lamivudine is a safe and effective antiviral HBV treatment both before and after renal transplantation. Lamivudine therapy commenced at transplantation should prevent early posttransplant reactivation and subsequent progression to cirrhosis and late liver failure. This preemptive therapy should also eradicate early liver failure from fibrosing cholestatic hepatitis. Because cessation of treatment may lead to severe lamivudine-withdrawal hepatitis, most patients require long-term therapy. The development of lamivudine-resistance will be accelerated by immunosuppression and may result in severe hepatitis flares with decompensation. Regular monitoring with liver function tests and HBV DNA measurements should enable early detection and rescue with adefovir. Chronic HCV and HBV infections are important causes of morbidity and mortality in renal transplant recipients. The best predictor for liver mortality is advanced liver disease at the time of transplant, and liver biopsy should be considered in all potential HBsAg+ or HCV+ renal transplant candidates without clinical or radiologic evidence of cirrhosis. Established cirrhosis with active viral infection should be considered a relative contraindication to isolated renal transplantation.

Hepatitis C virus seropositivity at the time of renal transplantation in the United States: associated factors and patient survival

National statistics for patient characteristics and survival of renal transplant recipients positive for hepatitis C virus (HCV+) at the time of renal transplant are presented. A historical cohort analysis of 33479 renal transplant recipients in the United States Renal Data System from 1 July, 1994 to 30 June, 1997 has been carried out. The medical evidence form was also used for additional variables, but because of fewer available values, this was analyzed in a separate model. Outcomes were patient characteristics and survival associated with HCV+. Of 28692 recipients with valid HCV serologies, 1624 were HCV+ at transplant (5.7% prevalence). In logistic regression analysis, HCV+ was associated with African-American race, male gender, cadaveric donor type, increased duration of pre-transplant dialysis, previous transplant, donor HCV+, recipient (but not donor) age, serum albumin, alcohol use, and increased all-cause hospitalizations. Diabetes and IgA nephropathy were less associated with HCV+. Total all-cause, unadjusted mortality was 13.1% in HCV+ vs. 8.5% in HCV- patients (p <0.01 by log rank test). In Cox regression, mortality was higher for HCV+ (adjusted hazard ratio = 1.23, 95% confidence interval = 1.01-1.49, p = 0.04). HCV+ recipients were more likely to be African-American, male, older, and to have received repeat transplants and donor HCV+ transplants. HCV+ recipients also had substantially longer waiting times for transplant. In contrast to recent studies, diabetes did not have an increased association with HCV+, perhaps due to limitations of the database. HCV+ recipients had increased mortality and hospitalization rates compared with other transplant recipients.

Hepatitis virus infections in heart transplant recipients: epidemiology, natural history, characteristics, and impact on survival

BACKGROUND & AIMS

We have observed a high prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection in heart transplant recipients (HTRs). The aim of this study was to assess the epidemiology, natural history, and clinical and biological characteristics of viral hepatitis in HTRs.

METHODS

From 1983 to 1992, 874 patients underwent heart transplantation at the Pitié-Salpêtrière Hospital, Paris, France, 459 of whom qualified for analysis. A total of 140 patients had posttransplantation hepatitis B, C, or non-A-E. Sixty-nine patients developed HBV infection, 49 HCV infection, 11 HBV-HCV coinfection, and 11 non-A-E hepatitis.

RESULTS

HBV was transmitted nosocomially from patient to patient, most likely during endomyocardial biopsies. HCV was mainly transmitted through blood transfusions or the transplanted organ. Clinical and biological findings after 2 years of follow-up showed that 3 patients with an HBV genotype A precore mutant had severe or subfulminant hepatitis and that patients with HBV and HCV infection always progressed to chronicity. In general, patients had mild alanine aminotransferase level increases, a high level of viral replication, and few severe histologic lesions, except for patients infected by precore HBV mutants. Patients coinfected by HBV and HCV tended to have more severe liver lesions. The survival rate 5 years after transplantation in patients with viral hepatitis (HBV, 81%; HCV, 89%; HBV and HCV coinfection, 100%; non-A-E hepatitis, 73%) was similar to that in patients without liver test abnormalities (76%). The actuarial survival curve was also similar in patients with or without liver test abnormalities.

CONCLUSIONS

In our experience, histologic liver lesions do not progress rapidly in patients with post-heart transplant infection caused by HBV or HCV. HBV or HCV infection seems to have little impact on the 5-year survival rate of HTRs.

A prospective study of hepatitis C viremia in renal allograft recipients

In an attempt to study the impact of HCV viremia on renal transplant clinical course and outcome, we prospectively followed 133 HBsAg-negative end stage renal disease (ESRD) patients, in whom HCV-RNA-PCR results were available, from the pre- to post-transplant period. Eighty (60%) ESRD patients tested PCR-positive, of these, 12 (15%) were anti-HCV negative by second generation ELISA. The viremic patients had a longer time on dialysis (p < 0.001), received more blood units (p < 0.001) and had a higher frequency of pre-transplantation liver disease (p < 0.001). Further, 41% of PCR-positive patients gave a history of antischistosomal treatment compared with 23% of PCR-negative ones (p = 0.048). Recipients with and without HCV viremia were followed for a mean of 31.8 +/- 5.8 (range 6-42) months and 29.8 +/- 9 (range 6-41) months respectively, p = 0.14. While the prevalence of HCV viremia increased from 60 to 64% at the last follow-up, the anti-HCV seroprevalence decreased from 63 to 61%. PCR-positive patients had higher rates of both acute (p = 0.005) and chronic (p < 0.001) liver disease after transplantation compared with PCR-negative patients. However, none of our HCV RNA positive recipients developed a fulminant liver disease or hepatic failure until the last follow-up. Stepwise logistic regression analysis identified pre-transplant liver disease (Odds ratio = 2.4; p = 0.07) and a cumulative corticosteroid dose in excess of 15 g at the last follow-up (Odds ratio = 3; p = 0.03) as independent predictors of post-transplant hepatic dysfunction in PCR-positive patients. Azathioprine was discontinued due to hepatic dysfunction in a significantly (p = 0.005) higher proportion of viremic patients compared with the non-viremic ones. There were no significant differences between PCR-positive and -negative patients in terms of frequencies and individual causes of graft and patient losses. Our results demonstrate that HCV infection is extremely prevalent in Egyptian hemodialysis patients and is responsible for most hepatic dysfunctions after transplantation. Although HCV viremia did not negatively affect graft or patient outcome until 31 months post-transplantation, the authors would recommend that a viremic patient should have a liver biopsy before transplantation and be immunosuppressed with caution post-transplantation. A longer follow-up may be required to exclude increased rates of HCV-induced hepatic mortalities.

Tuberculosis in renal transplant recipients

BACKGROUND

Tuberculosis is an important cause of morbidity and mortality in renal transplant recipients, but there are insufficient data regarding the efficacy and complications of therapy and of INH prophylaxis.

METHODS

This study is a retrospective review of the records of 880 renal transplant recipients in two centers in Turkey.

RESULTS

Tuberculosis developed in 36 patients (4.1%) at posttransplant 3-111 months, of which 28 were successfully treated. Eight patients (22.2%) died of tuberculosis or complications of anti-tuberculosis therapy. Use of rifampin necessitated a mean of 2-fold increase in the cyclosporine dose, but no allograft rejection occurred due to inadequate cyclosporine levels. Hepatotoxicity developed in eight patients during treatment, two of whom died due to hepatic failure. No risk factor, including age, gender, renal dysfunction, hepatitis C, or past hepatitis B infection, was found to be associated with development of hepatic toxicity. A subgroup of 36 patients with a past history of or radiographic findings suggesting inactive tuberculosis, was considered to be at high risk for developing active disease, of whom 23 were given isoniazid (INH) prophylaxis. None versus 1 of 13 (7.7%) of cases with and without INH prophylaxis, respectively, developed active disease (P>0.05). None of the patients receiving INH had hepatic toxicity or needed modification of cyclosporine dose.

CONCLUSIONS

These data show that tuberculosis has a high prevalence in transplant recipients, that it can effectively be treated using rifampin-containing antituberculosis drugs with a close follow-up of serum cyclosporine levels, and that INH prophylaxis is safe but more experience is needed to define the target population.

Impact of hepatitis B and C virus on kidney transplantation outcome

The impact of hepatitis B (HBV) and C (HCV) on patient survival after kidney transplantation is controversial. The aims of this study were (1) to assess the independent prognostic values of HBsAg and anti-HCV in a large renal transplant population, (2) to compare infected patients with noninfected patients matched for factors possibly associated with graft and patient survival, and (3) to assess the prognostic value of biopsy-proven cirrhosis. Eight hundred thirty-four transplanted patients were included: 128 with positive HBsAg (group I), 216 with positive anti-HCV (group II), and 490 without serological markers of HBV and HCV (group III). Fifteen percent and 29% of patients were HBsAg-positive and anti-HCV-positive, respectively. Ten-year survivals of group I (55 +/- 6%) and group II (65 +/- 5%) were significantly lower than survival of group III (80 +/- 3%, P <.001). At 10 years, among overall patients with HCV screening (n = 834), four variables had independent prognostic values in patient survival: age at transplantation (P <.0001), year of transplantation (P =.02), biopsy-proven cirrhosis (P =.03), and presence of HCV antibodies (P =.02). In the case control study, comparison of infected patients with their matched control patients showed that age at transplantation (P <.05), HBsAg (P =.005), and anti-HCV (P =.005) were independent prognostic factors. HCV, biopsy-proven cirrhosis, and age are independent prognostic factors of 10-year survival in patients with kidney grafts. The case-control study showed that anti-HCV and HBsAg were independently associated with patient and graft survivals. In infected patients, a routine liver histological analysis would improve selection of patients for renal transplantation.

Donor hepatitis C virus status does not adversely affect short-term outcomes in HCV+ recipients in renal transplantation

BACKGROUND

Recipient hepatitis C virus (HCV) seropositivity has been associated with inferior outcomes in renal transplantation (RTx). We sought to determine whether donor HCV+ status influenced the incidence of rejection, liver dysfunction, and graft survival in HCV+ recipients.

METHODS

We reviewed 44 HCV+ recipients (R+) receiving RTx from HCV+ (D+) and HCV- (D-) donors between February 1991 and September 1996. All patients were followed to the end of the study period (mean=36 months, range=12-60 months). We compared the R+ group with a demographically matched cohort of 44 HCV- recipients (R-).

RESULTS

Of the 44 R+, 25 (57%) had a total of 48 rejection episodes. Among the 44 R-, 32 (73%) had 58 rejection episodes (P>0.1). Within the R+ group, 28 were D+/R+; of these 14 (50%) had 27 rejection episodes, whereas among the 16 D-/R+, 11 (68%) had 21 rejection episodes (P>0.3). Graft and patient survival was similar in both the groups (86.4% and 91%, respectively). Liver dysfunction was slightly increased in the R+ group (4/44 vs. 0/44, P>0.1), with one death due to liver failure in this group.

CONCLUSION

Donor HCV+ status had no influence on outcomes in HCV+ recipients after kidney transplantation in the short term. The incidence of rejection, graft loss, and mortality was comparable between the D+/R+ and D-/R+ groups. Furthermore, rejection, graft loss, and death were identical in R+ and R-groups throughout the 5-year study period. We therefore conclude that HCV+ recipients can safely receive kidney transplants without concern about donor HCV status or fear of adverse events from their own HCV+ status.

Case report: Clinical and virological analyses of a patient positive for hepatitis C virus-RNA by branched DNA assay but negative for anti-hepatitis C virus antibodies

Infection with hepatitis C virus (HCV) is usually diagnosed by the presence of antibodies against fusion proteins or peptides derived from different regions of the HCV genome. However, a subgroup of patients with HCV viraemia are seronegative for antibody against hepatitis C virus (anti-HCV) by conventional antibody assays. We analysed serum samples from a patient with liver cirrhosis who tested negative for anti-HCV by a second-generation assay, but positive for HCV-RNA by reverse transcription polymerase chain reaction (RT-PCR) and branched DNA signal amplification. To identify possible mutations that could explain the failure of detection of anti-HCV by second-generation assay, PCR-amplified DNA fragments of the core region derived from the serum were cloned and sequenced. Nucleotide (nt) and amino acid (aa) sequence analyses (nt 1-486, aa 1-162) showed no mutations revealing stop codons, frame-shifts, deletions or insertions, but the presence of two amino acid substitutions (aa 75 and 91) when compared with HCV-J, a prototype strain of genotype 1b isolated from a Japanese patient. One of these two mutations (aa 75) was situated in the second hydrophilic domain of the core peptide, but analysis of the hydropathy profile showed only a little change. The two mutations were identical to those identified in other Japanese HCV isolates. The serum immunoglobulin level and T and B cell counts were normal in our patient. Our data suggest that the absence of anti-HCV in this patient was not due to mutations of major epitopes of HCV. Low-dose prednisolone administration just after transfusion may have induced immunological tolerance against HCV in this patient.

The impact of renal transplantation on survival in hepatitis C-positive end-stage renal disease patients

Hepatitis C virus (HCV) infection is common in end-stage renal failure patients. It is not known whether the prognosis of HCV-positive patients differs depending on whether they remain on dialysis or receive a kidney transplant. To address this question, we compared the outcomes of HCV-positive renal transplant recipients and HCV-positive patients who were acceptable candidates but had not yet received transplants. We reviewed all patients referred to our institution for renal transplantation evaluation between January 1992 and December 1995. Anti-HCV antibody was detected in 151 of 2,053 (7.4%) patients. HCV-positive patients were more often male (74% v 56%; P < 0.0001), black (68% v 49%; P = 0.001), unemployed (87% v 74%; P = 0.0004), on dialysis (88% v 78%; P = 0.0026), and on dialysis longer (30 +/- 44 months v 13 +/- 23 months; P = 0.0001) than HCV-negative patients. We determined the outcomes of HCV-positive patients who had at least 2 years' follow-up. Thirty-three HCV-positive patients received kidney transplants (group I); 25 HCV-positive patients were acceptable transplant candidates but had not yet received an allograft (group II). Group I and II HCV-positive patients were similar with respect to age, race, duration of dialysis, cause of renal failure, prevalence of heart disease, and results of liver function tests. Survival was significantly decreased in group II versus group I (P = 0.043). Our study showed that HCV-positive renal transplant recipients had a better survival than similar HCV-positive patients awaiting transplantation.