High prevalence of hepatitis C virus (HCV) RNA in dialysis patients: failure of commercially available antibody tests to identify a significant number of patients with HCV infection. Copenhagen Dialysis HCV Study Group

Global epidemiology of hepatitis C virus in dialysis patients: A systematic review and meta-analysis

Dialysis is a replacement therapy for patients with End-Stage Renal Disease (ESRD). Patients on dialysis are at high risk of acquiring hepatitis C virus (HCV), which has become a leading cause of morbidity and mortality in this population. There is a wide range of prevalence of HCV in dialysis populations around the world. It is still unknown how prevalent HCV infection is among worldwide dialysis patients (including those undergoing hemodialysis and peritoneal dialysis). A review was conducted to estimate the global epidemiology of hepatitis C in dialysis patients. We searched PubMed, Excerpta Medica Database (Embase), Global Index Medicus and Web of Science until October 2022. A manual search of references from relevant articles was also conducted. Heterogeneity was evaluated by the χ2 test on Cochrane's Q statistic, and the sources of heterogeneity were investigated using subgroup analysis. In order to assess publication bias, funnel plots and Egger tests were conducted, and pooled HCV prevalence estimates were generated using a DerSimonian and Laird meta-analysis model. The study is registered with PROSPERO under CRD42022237789. We included 634 papers involving 392160 participants. The overall HCV case fatality rate was 38.7% (95% CI = 28.9-49). The global prevalence of HCV infection in dialysis population group were 24.3% [95% CI = 22.6-25.9]. As indicated by UNSD region, country, dialysis type, and HCV diagnostic targeted; Eastern Europe had the highest prevalence of 48.6% [95% CI = 35.2-62], Indonesia had 63.6% [95% CI = 42.9-82], hemodialysis patients had 25.5% [95% CI = 23.8-27.3], and anti-HCV were detected in 24.5% [95% CI = 22.8-26.2]. Dialysis patients, particularly those on hemodialysis, have a high prevalence and case fatality rate of HCV infection. Hemodialysis units need to implement strict infection control measures.

Dose-Dependent Hepacivirus Infection Reveals Linkage between Infectious Dose and Immune Response

More than 70 million people worldwide are still infected with the hepatitis C virus 30 years after its discovery, underscoring the need for a vaccine. To develop an effective prophylactic vaccine, detailed knowledge of the correlates of protection and an immunocompetent surrogate model are needed. In this study, we describe the minimum dose required for robust equine hepacivirus (EqHV) infection in equids and examined how this relates to duration of infection, seroconversion, and transcriptomic responses. To investigate mechanisms of hepaciviral persistence, immune response, and immune-mediated pathology, we inoculated eight EqHV naive horses with doses ranging from 1-2 copies to 1.3 × 106 RNA copies per inoculation. We characterized infection kinetics, pathology, and transcriptomic responses via next generation sequencing. The minimal infectious dose of EqHV in horses was estimated at 13 RNA copies, whereas 6 to 7 copies were insufficient to cause infection. Peak viremia did not correlate with infectious dose, while seroconversion and duration of infection appeared to be affected. Notably, seroconversion was undetectable in the low-dose infections within the surveillance period (40 to 50 days). In addition, transcriptomic analysis revealed a nearly dose-dependent effect, with greater immune activation and inflammatory response observed in high-dose infections than in low-dose infections. Interestingly, inoculation with 6-7 copies of RNA that did not result in productive infection, but was associated with a strong immune response, similar to that observed in the high-dose infections. IMPORTANCE We demonstrate that the EqHV dose of infection plays an important role for inducing immune responses, possibly linked to early clearance in high-dose and prolonged viremia in low-dose infections. In particular, pathways associated with innate and adaptive immune responses, as well as inflammatory responses, were more strongly upregulated in high-dose infections than in lower doses. Hence, inoculation with low doses may enable EqHV to evade strong immune responses in the early phase and therefore promote robust, long-lasting infection.

Comparing RT-qPCR and Hepatitis C Virus Antigen Detection Assay for Detecting Active Infection in Blood Donors in Fars Province, Iran

Background: Immunoassay is still used to detect hepatitis C virus (HCV) antibodies in donated blood in many developing countries. However, an immunoblotting confirmation test is needed to confirm positive results. Objectives: We compared the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of nucleic acid testing and HCV core antigen (HCVcAg) detection in the serum samples of blood donors with HCV antibodies to determine active infection. Methods: Overall, 90 serum samples from blood donors referred to Fars Blood Transfusion Organization, Iran during March 2017-March 2019 and initially tested for HCV antibodies were included in the study. Enzyme immunoassays were used to detect the HCV antigen and anti-HCV antibody. A commercial reverse transcription-polymerase chain reaction (RT-PCR) kit was used to quantify HCV RNA. The HCV genotypes were also determined by DNA sequencing. In order to compare the HCVcAg detection method with the RT-qPCR reference method, sensitivity, specificity, performance, PPV, and NPV were calculated. Results: Out of 90 serum samples, 73 were positive for anti-HCV antibody, and 17 sera were negative. The HCV RNA was detected in 60 (82%) of anti-HCV antibody-positive samples, whereas the HCVcAg test detected HCV antigen in 54 (74%) of the samples, indicating a significant correlation between the two assays (r = 0.86). The overall sensitivity and specificity for HCVcAg detection method were 93.85% [95% confidence interval (CI): 84.99 - 98.3%] and 100% (95% CI: 94.64 - 100%), respectively. Based on the statistical analysis, the accuracy of the antigen detection test was 94.83% (95% CI: 87.26 - 98.58%). Moreover, the agreement between HCV RNA detection using RT-qPCR and HCVcAg detection was 97.78% (kappa value: 0.94). Conclusions: The sensitivity and specificity of HCVcAg detection in blood donors were ideal compared to the RT-qPCR reference method. However, the method should be tested on more HCV antibody-positive and -negative samples. Furthermore, our study revealed a significant association between the number of RT-qPCR-positive cases and the cases diagnosed by the HCVcAg detection method for screening and detecting active HCV infection in blood donors.

Prevalence of hepatitis C among haemodialysis patients in a tertiary care hospital in south India

Background and Objectives:

Hepatitis C is the most common hepatotropic viral infection that affects patients on maintenance hemodialysis. Most of the laboratories in India depend on HCV antibody detection by ELISA. PCR based studies on detection of HCV RNA among haemodialysis patients are very scanty in India. The current study was undertaken to find the prevalence of HCV among haemodialysis patients by ELISA and PCR.

Materials and Methods:

This prospective study was conducted from January to May 2018 in a total of 100 samples. Patients more than 18 years of age, who had undergone at least 15 sessions of dialysis were enrolled in the study. All samples were screened for HCV antibody by ELISA and HCV RNA by PCR. Data regarding age and gender of the patients, history of blood transfusion, duration of hemodialysis, total bilirubin levels were collected from medical records.

Results:

Among the 100 samples, only one was positive for HCV antibody by ELISA. Eight samples were positive for HCV RNA by PCR. In this study 62.5% of the HCV positives had a previous history of blood transfusion. Duration of dialysis was more among the HCV positive group but there was no statistical significance.

Conclusion:

This is the first study from the southern state of Kerala in India showing the prevalence of HCV among hemodialysis patients by PCR. Our study showed an overall HCV prevalence of 8% by PCR. All the PCR positive samples were negative by 3rd generation ELISA which is an alarming finding and further justifies the need for PCR for detecting HCV.

Prevalence and genotyping pattern of hepatitis C virus among patients on maintenance hemodialysis at five centers in Pune, India

Background

Worldwide prevalence of Hepatitis C virus (HCV) infection hemodialysis (HD) ranges from 1 to 84.6% with serious complications. Assessment of prevalence, risk factors, and genotyping of HCV infection in patient on HD was carried out at Pune, India.

Methods

A total of 250 patients on HD from five HD centers were recruited and tested for anti-HCV antibody using third-generation enzyme-linked immunosorbent assay (ELISA). Qualitative HCV RNA detection was carried out by nested reverse transcriptase polymerase chain reaction (RT-PCR). Genotyping and sequencing were carried out using the BigDye Terminator cycle sequencing ready reaction kit.

Results

Mean age of patients was 47.3 years. Forty-seven cases out of a total of 250 were reactor for HCV antibody. Overall prevalence rate was 18.8% ranging from 6.7% to 35.6% in the five centers. Of total, 44.1% of females and 13.5% of males were HCV infected. The mean duration of HD in HCV-infected patients was 6.03 years. Prevalence was higher in patients aged > 5 years on HD with higher number of blood transfusions. Thirty-six cases were positive for HCV RNA. Only one HCV RNA was detected among the 203 anti-HCV negative samples. Discordance between antibody and HCV RNA positivity was noted. Seventeen infected cases had changed dialysis centers four times. Thirteen cases were HBsAg positive, of which six cases were coinfected with HCV. Thirty-seven samples were genotyped.

Conclusion

The predominant genotype was 1a (54.1%) followed by 1b (43.2%) and 3a (2.7%). Highest prevalence of HCV (35.6%) and intracenter PNI of 99.3% of genotype 1b (84.6%) in center 3 indicates a possible nosocomial transmission.

Diagnostic Dilemmas in Hepatitis C Virus Infection for Hemodialysis Patients

BACKGROUND

Hepatitis C virus (HCV) is a leading cause of chronic hepatitis in dialysis patients. The diagnosis of HCV infection in these patients is predominantly based on laboratory tests because of the specificity of the clinical course of the disease.

AIM

The present prospective study aimed at determining very accurately the prevalence rate of HCV infection in patients on dialysis by simultaneously testing them for anti-HCV and for HCV RNA levels.

MATERIALS AND METHODS

For the present cross-sectional longitudinal study we recruited and followed up 93 patients from St George University Hospital Hemodialysis Unit between July 2013 and December 2014. All patients were tested for anti-HCV and HCV RNA. The anti-HCV negative patients were tested for anti-HCV and HCV RNA at least twice at intervals of 6 months or more (up to 12 months). Anti-HCV antibodies were identified using a third generation ELISA assay. Commercial kits for real-time polymerase chain reaction (RT-PCR) were used to detect HCV RNA in the plasma and mononuclear cells. Aminotransferase and gammaglutamyl transpeptidase levels were studied to find if liver inflammation was present.

RESULTS

The total seroprevalence in 68 patients was 20.6% (14). Of these, 10 patients were viremic (HCV RNA+/anti-HCV+), and 4 patients (5.9%) had discordant results (anti-HCV+/HCV RNA-). Acute hepatitis was detected in one patient. Duration of dialysis in HCV viremic patients was longer than that in aviremic patients (p=0.005).

CONCLUSIONS

The present study suggests that HCV infection in dialysis patients can be diagnosed more accurately if these patients are tested using two diagnostic methods - a serological test and a biomolecular assay. Further studies with larger sample size may prove the feasibility of such approach for all dialysis patients in this country.

Hepatitis C Virus Infection in Patients with End-Stage Renal Disease: A Study from a Tertiary Care Centre in India

BACKGROUND

Hepatitis C Virus (HCV) infection is common in patients with end stage renal disease (ESRD) and is an important cause of liver disease. We describe the demographic, clinical and biochemical profile of these patients from a tertiary care center of north India.

METHODS

Records of consecutive patients of HCV infection with ESRD on maintenance hemodialysis or with renal transplantation who presented to our unit from January 2009 to June 2013 were analyzed. The diagnosis of HCV was based on HCV-RNA positivity and/or positive anti-HCV serology. Those with positive anti-HCV serology and negative HCV-RNA on two occasions at 3-month interval, without treatment with interferon, were excluded.

RESULTS

140 patients (median age 44 years [range 18-68], 69% males) were included. Six patients had co-infections (HBV 5, HIV 1). Most (99, 71%) patients were asymptomatic for liver disease and HCV was identified either on routine screening (39, 28%) or during investigation for raised liver enzymes (60, 43%). Remaining 41 (29%) were symptomatic for liver disease, either in the form of jaundice alone (14, 10%), or decompensated liver disease (27, 19%). Median time between initiation of hemodialysis and HCV detection was 33 (range 0-124) months. Thirty-four (27%) patients had received renal transplantation. In 11 patients HCV was detected after renal transplantation. In 23 (18%) patients anti-HCV was falsely negative but HCV-RNA was positive. Nearly 35% patients had concomitant diabetes. Median Bilirubin, AST, and ALT were 1.1 mg/dL, 42 IU/L and 44 IU/L, respectively. HCV-RNA was more than 5 log in 49/88(59%) patients. Median HCV-RNA was 6.5 × 10(5) IU/ml (Range 650 to >10 million IU/ml). Genotype-1 was the commonest genotype (30/56, 54%) followed by genotype-3 (17/56, 30%).

CONCLUSION

HCV infection is usually asymptomatic in patients with ESRD, however, it may lead to jaundice and decompensated liver disease. False negative anti-HCV is quite common. We found that genotype-1 was commoner than genotype-3 in our cohort of ESRD patients. Most of the patients have high viral load.

Cell therapies and regenerative medicine

Molecular and cell biology has resulted in major advances in our understanding of disease pathogenesis as well as in novel strategies for the diagnosis, therapy and prevention of human diseases. Based on modern molecular, genetic and biochemical methodologies, it is on the one hand possible to identify disease-related point mutations and single nucleotide polymorphisms, for example. On the other hand, using high throughput array and other technologies, it is for example possible to simultaneously analyze thousands of genes or gene products (RNA and proteins), resulting in an individual gene or gene expression profile ('signature'). Such data increasingly allow defining the individual disposition for a given disease and predicting disease prognosis as well as the efficacy of therapeutic strategies in the individual patient ('personalized medicine'). At the same time, the basic discoveries in cell biology, including embryonic and adult stem cells, induced pluripotent stem cells, genetically modified cells and others, have moved regenerative medicine into the center of biomedical research worldwide with a major translational impact on tissue engineering as well as transplantation medicine. All these aspects have greatly contributed to the recent advances in regenerative medicine and the development of novel concepts for the treatment of many human diseases, including liver diseases.

Usefulness of liver biopsy in anti-hepatitis C virus antibody-positive and hepatitis C virus RNA-negative kidney transplant recipients

BACKGROUND

Some guidelines recommend a liver biopsy to all anti-hepatitis C virus (HCV) antibody-positive kidney transplant (KT) recipients. However, in the case of HCV RNA-negative KT recipients, the benefit of a liver biopsy is unclear. We examined the usefulness of a liver biopsy for anti-HCV antibody-positive and HCV RNA-negative patients by analyzing the hepatic histologic findings and clinical outcomes.

METHODS

A total of 30 anti-HCV antibody-positive patients who underwent liver biopsy before KT at Asan Medical Center were retrospectively recruited. The patients were divided into two groups based on HCV RNA positivity: 17 patients were positive and 13 patients were negative. Histologic evidence of hepatic inflammation and fibrosis was assessed using the METAVIR score, and clinical outcomes, including mortality, graft loss, and progression of liver disease, were compared.

RESULTS

The mean histologic activity scores for inflammation and fibrosis for the HCV RNA-positive and HCV RNA-negative groups were significantly different (inflammation score 1.11 ± 0.85 vs. 0.46 ± 0.51; P=0.01 and fibrosis score 1.05 ± 1.24 vs. 0.15 ± 0.37; P=0.01, respectively). The overall rates of mortality and graft loss were not significantly different between the two groups. Progression of liver disease was noted in the HCV RNA-positive group only.

CONCLUSION

The HCV RNA-negative group showed no evidence of liver disease progression. Neither did they show any histologic evidence of liver inflammation and fibrosis before KT. Therefore, it appears that liver biopsy is not necessary in anti-HCV antibody-positive and HCV RNA-negative KT recipients.

Evaluation of an isolation program of hepatitis C virus infected hemodialysis patients in some hemodialysis centers in egypt

Introduction. Hepatitis C virus (HCV) infection is a significant cause of morbidity and mortality in hemodialysis (HD) patients. Several studies demonstrated nosocomial transmission of HCV among HD patients. Aim. We aimed to evaluate the isolation program of HCV seropositive patients among a group of Egyptian haemodialysis patients to decrease the incidence of HCV seroconversion. Methods. One hundred and fourteen HCV seronegative patients who were receiving regular haemodialysis in different four haemodialysis units in Egypt. The first group included forty six patients on regular hemodialysis in two centers following strict isolation of the HCV seropositive patients, and the second group included sixty eight patients on regular hemodialysis in the other two centers not following this strict isolation. All these patients were followed up over a period of 36 months. Results. There was a significantly higher incidence of HCV seroconversion of patients on hemodialysis in units not following strict isolation of HCV seropositive patients (42.9%) than those on regular hemodialysis in units following strict isolation (14.8%). Conclusions. In HD units with a high prevalence of HCV+ patients, strict isolation of HCV+ patients in combination with implementation of universal prevention measures can limit the spread of HCV infection in HD patients.

High false-negative rate of anti-HCV among Egyptian patients on regular hemodialysis

Routine serological testing for hepatitis C virus (HCV) infection among hemodialysis (HD) patients is currently recommended. A dilemma existed on the value of serology because some investigators reported a high rate of false-negative serologic testing. In this study, we aimed to detect the false-negative rate of anti-HCV among Egyptian HD patients. Seventy-eight HD patients, negative for anti-HCV, anti-HIV, and hepatitis B surface antigen, were tested for HCV RNA by reverse transcriptase polymerase chain reaction (RT-PCR). In the next step, the viral load was quantified by real-time PCR in RT-PCR-positive patients. Risk factors for HCV infection, as well as clinical and biochemical indicators of liver disease, were compared between false-negative and true-negative anti-HCV HD patients. The frequency of false-negative anti-HCV was 17.9%. Frequency of blood transfusion, duration of HD, dialysis at multiple centers, and diabetes mellitus were not identified as risk factors for HCV infection. The frequency of false-negative results had a linear relation to the prevalence of HCV infection in the HD units. Timely identification of HCV within dialysis units is needed in order to lower the risk of HCV spread within the HD units. The high false-negative rate of anti-HCV among HD patients in our study justifies testing of a large scale of patients for precious assessment of effectiveness of nucleic acid amplification technology testing in screening HD patient.

Management of hepatitis C in patients with chronic kidney disease

Chronic kidney disease represents a global health problem. Chronic hepatitis C virus (HCV) infection is prevalent in patients with end stage renal disease (ESRD) on hemodialysis (HD) and in renal transplant recipients with significant impact on morbidity and mortality. Furthermore, HCV can cause various forms of glomerulopathy with the predominant type being cryglobulinemia associated membranoproliferative glomerulonephritis. Liver enzymes are traditionally used as markers of liver injury; however, there is wide variation in aminotransferase levels in patients with ESRD. Therefore, diagnosis of chronic hepatitis C (CHC) in patients with ESRD is based on HCV antibody testing and further confirmation with polymerase chain reaction testing. Current standard therapy for CHC is composed of pegylated interferon and ribavirin. However, this combination is challenging in patients with ESRD due to its tolerability. We describe in this review relevant issues in epidemiology, diagnosis and management of CHC in ESRD, HD and renal transplant recipients.

Treatment of hepatitis C virus infection in patients with end-stage renal disease

Hepatitis C virus (HCV) infection is a major health problem in patients with end-stage renal disease (ESRD). The incidence of acute HCV infection during maintenance dialysis is much higher than that in the general population because of the risk of nosocomial transmission. Following acute HCV infection, most patients develop chronic HCV infection, and a significant proportion develop chronic hepatitis, cirrhosis, and even hepatocellular carcinoma. Overall, chronic hepatitis C patients on hemodialysis bear an increased risk of liver-related morbidity and mortality, either during dialysis or after renal transplantation. Interferon (IFN) therapy is modestly effective for the treatment of HCV infection in ESRD patients. Conventional or pegylated IFN monotherapy has been used to treat acute hepatitis C in ESRD patients with excellent safety and efficacy. Regarding chronic hepatitis C, approximately one-third of patients can achieve a sustained virological response (SVR) after conventional or pegylated IFN monotherapy. The combination of low-dose ribavirin and conventional or pegylated IFN has further improved the SVR rate in treatment-naïve or retreated ESRD patients in clinical trials. Similar to the treatment of patients with normal renal function, baseline and on-treatment HCV virokinetics are useful to guide optimized therapy in ESRD patients. Of particular note, IFN-based therapy is not recommended at the post-renal transplantation stage because of the low SVR rate and risk of acute graft rejection. In conclusion, ESRD patients with HCV infection should be encouraged to receive antiviral therapy, and those who achieve an SVR usually have long-term, durable, virological, biochemical, and histological responses.

Prevalence and risk factors of hepatitis B and C viruses among haemodialysis patients in Gaza strip, Palestine

Background

The prevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) and its associated risk factors among haemodialysis (HD) patients in Gaza strip was investigated using serological and molecular techniques.

Results

The overall prevalence of HBV among the four HD centers was 8.1%. The main risk factors were HD center (p = 0.05), history of blood transfusion (p < 0.01), and treatment abroad (p = 0.01). The overall prevalence of HCV among the four HD centers was 22%. The main risk factors were HD center (p < 0.01), time duration on HD (p < 0.01), history of blood transfusion (p < 0.01), treatment abroad (p < 0.01), and history of blood transfusion abroad (p < 0.01). Serum aminotransferases levels decreased in HD patients compared with normal population but still there was a direct association between the activity of liver enzymes and both HBV (p < 0.01) and HCV (p < 0.01) infection.

Conclusion

The much higher prevalence of Hepatitis viruses among HD patients compared to the normal population of Gaza strip indicates a causative relation between HD and hepatitis viruses transmission. Therefore extremely careful observation of preventive infection control measures is essential to limit Hepatitis viruses' transmission in HD centers.

HCV response in patients with end stage renal disease treated with combination pegylated interferon alpha-2a and ribavirin

GOALS

To determine the efficacy and safety of combination therapy in patients with hepatitis C virus (HCV) and end-stage renal disease (ESRD).

BACKGROUND

There is little data on the treatment of ESRD patients with pegylated interferon and ribavirin. We designed a pilot study to determine the initial and 12-week posttreatment viral response.

STUDY

A nonrandomized, prospective observational study of adjusted-dose combination therapy. Twenty patients were enrolled and began pegylated interferon at 135 microg/wk SC, and 4 weeks later ribavirin was started at 200 mg PO weekly, increasing gradually to 3 times a week for a total of 48 weeks.

RESULTS

Twenty patients: M:F 18:2; mean age 52.4 years; genotype 1: 18, non-genotype 1: 2. Of the 20 patients, 5 withdrew before starting treatment. Of the 11 patients who reached 3 months, 6 had early virologic response, defined as at least a 2-log drop in their HCV count (54.5%). Of the 5 patients who were treated for 1-year, only 1 patient had a response 12 weeks after treatment. Side effects included 4 cases of anemia and 1 patient with headache.

CONCLUSIONS

The initial response rate in individuals taking 3 months of treatment in our study is comparable with studies in non-ESRD patients with no serious adverse side effects. However, the sustained posttreatment rate was low. This demonstrates that combination therapy is a safe therapeutic option in the ESRD population with HCV infection which needs further testing to determine if increasing the length of treatment and/or the dose of ribavirin will affect posttreatment rates.

Chronic viral hepatitis as a public health issue in the world

This article will focus on the impact caused by chronic viral hepatitis B and C globally and will discuss public health measures that have to be implemented in order to prevent and control these diseases. Chronic viral hepatitis is a major global public health problem, an important cause of morbidity and mortality from sequelae which include chronic hepatitis, cirrhosis and primary liver cancer. Being a 'silent' disease, the contribution of chronic hepatitis to global morbidity and mortality is generally underestimated. Hepatitis B and C prevention and control should seek to reduce both the incidence of new infections and the risk of chronic liver disease. A comprehensive public health prevention programme should include the prevention and detection of HBV and HCV infections, the diagnosis and control of viral hepatitis related chronic liver disease, conducting surveillance and monitoring the effectiveness of prevention activities, and setting up a research agenda.

Hepatitis C virus and kidney disease

Hepatitis C virus (HCV) infection remains frequent in patients on renal replacement therapy and has an adverse impact on survival in infected patients on chronic hemodialysis as well as renal transplant (RT) recipients. Nosocomial spread of HCV within dialysis units continues to occur. HCV is also implicated in the pathogenesis of renal dysfunction often mediated by cryoglobulins leading to chronic kidney disease as well as impairing renal allograft function. The role of antiviral therapy for hepatitis C in patients with renal failure remains unclear. Monotherapy with conventional interferon (IFN) for chronic hepatitis C is probably more effective in dialysis than in non-uraemic patients but tolerance is lower. Limited data only are available about monotherapy with pegylated interferon and combination therapy (pegylated IFN plus ribavirin) for chronic HCV in the dialysis population. Clinical experience with antiviral therapy for acute HCV in dialysis population is encouraging. Interferon remains contraindicated post-RT because of concerns about precipitating graft dysfunction. Sustained viral responses obtained by antiviral therapy in renal transplant candidates are durable after renal transplantation and may reduce HCV-related complications after RT (post-transplant diabetes mellitus, HCV-related glomerulonephritis, and chronic allograft nephropathy).

Sensitivity of a rapid immuno-chromatographic test for hepatitis C antibodies detection

BACKGROUND AND OBJECTIVES

Enzyme-linked immunoassays (ELISA) are the most widely used anti-hepatitis C virus (HCV) screening tests but simple, instrument and electricity-free screening tests have been developed with results available in a few minutes.

METHODS

The sensitivity of a rapid immuno-chromatographic assay for the detection of anti-HCV antibodies was evaluated on 421 HCV RNA-positive samples from chronic carriers and compared with ELISA method.

RESULTS

The sensitivity of the ELISA method was 99.3% and the sensitivity of the rapid test was 95.5%. False negative results were independent of HCV genotype, but were associated with human immunodeficiency virus (HIV)-positive status. Among HIV-negative people, sensitivities of the rapid test and the EIA assay were 99.2% and 100%, respectively. Whereas among HIV-positive people, sensitivities were 77.5% and 96.3%.

CONCLUSIONS

The immuno-chromatographic test is rapid and simple, and could be used along with rapid anti-HIV determination, in settings with limited facilities or when rapid results are required.

Hepatitis C virus infection and the dialysis patient

Hepatitis C virus (HCV) remains common in patients undergoing regular dialysis and is an important cause of liver disease in this population both during dialysis and after renal transplantation (RT). Anti-HCV screening of blood products has almost eliminated posttransfusion HCV infection but acquisition of HCV continues to occur in dialysis patients because of nosocomial spread. The natural history of HCV in dialysis population is not completely understood though recent data show that HCV infection has a detrimental role on survival of chronic dialysis patients. Several clinical trials have suggested that the response rate to conventional interferon (IFN) is higher in dialysis patients than those with normal kidney function but tolerance is lower. There are only limited data about pegylated IFN alone or in association with ribavirin for hepatitis C in dialysis population. IFN remains contraindicated post-RT because of concern about precipitating graft dysfunction; however, preliminary evidence shows the durability of sustained response to antiviral therapy pre-RT after renal transplant. Successful pretransplant therapy is associated with several benefits after RT including reduced incidence of posttransplant diabetes mellitus and de novo glomerulonephritis in HCV-infected recipients.

Prevalence of occult hepatitis B and hepatitis C virus infections in Turkish hemodialysis patients

BACKGROUND AND OBJECTIVE

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are important causes of morbidity and mortality in maintenance hemodialysis patients. Although their exact prevalence is not known, HBV and HCV viral infections and occult viral hepatitis are frequent in these patients. This study aimed to determine the prevalence of occult HBV and HCV infections in maintenance hemodialysis patients.

MATERIALS AND METHODS

One hundred and eighty-eight end-stage renal disease patients on maintenance hemodialysis (100 male, mean age 49+/-29 [16-80] years, and mean duration of hemodialysis 98+/-66 [12-228] months) were enrolled in this study. Serological markers for HBV and HCV were determined with immunoenzymatic assay (ELISA) by using commercial diagnostic kits (Access and BioRad, Beckman-Coulter). HCV-RNA (Cobas Amplicor HCV kit) and HBV-DNA (Artus GmbH HBV kit) were determined quantitatively by polymerase chain reaction.

RESULTS

Among the patients screened, 25 (13.3%) had HBV infection alone and 38 (20.2%) had HCV infection alone, while seven (3.7%) had dual infection of both viruses. Serological markers for occult hepatitis B and occult hepatitis C were positive in five (2.7%) and nine (4.8%) of the patients, respectively. Isolated anti-HBc was positive in 12 (6.4%) of all patients, three (7.9%) of the patients with anti-HCV and two (40%) of the patients with occult hepatitis B. Isolated anti-HBc positivity was more frequent in patients with occult hepatitis B than in those without (40% [2/5] vs. 5.5% [10/183], p=0.002). None of the patients with HCV had occult hepatitis B.

CONCLUSIONS

Both occult and non-occult forms of HCV infection are more prevalent than HBV infection in hemodialysis patients. Especially the patients with isolated anti-HBc positivity should be tested for probable occult hepatitis B infection.

[Clinical assessment of Monolisa HCV Ag-Ab ULTRA (Bio-Rad) in a general hospital]

INTRODUCTION

To evaluate a new test based on simultaneous detection of HCV antibodies and antigen (Monolisa HCV Ag/Ab ULTRA; Bio-Rad, Marnes la Coquette, France).

METHODS

We studied samples from two groups of patients and 7 commercial HCV seroconversion panels (75 samples). Group 1: 1360 serum samples from patients referred for routine testing of anti HCV antibodies. Group 2: 333 serum samples from 183 hemodialysis patients. All samples were tested by the Ortho HCV 3.0 technique (Ortho-Clinical Diagnostics, Amersham, UK) and the Monolisa HCV Ag-Ab ULTRA technique.

RESULTS

Group 1: Seventy-four of 1360 serum samples were positive by Ortho HCV and 77 by Monolisa. In 1353 samples, the results with the two tests were concordant: 1281 negative and 72 positive. Five samples were positive only by Monolisa and 2 only by Ortho (overall agreement: 99.5%). Group 2: Results were concordant in 325 samples, 308 negative and 17 positive. Seven samples were positive by Monolisa and negative by Ortho. The sensitivity of the Monolisa test in hemodialysis patients was clearly higher than that of the Ortho test (100% and 70.8%, respectively). Monolisa detected HCV infection in 43 of 75 samples from the seroconversion panels; only 18 positive samples were detected by Ortho HCV. Monolisa reduced the window period by up to 72 days.

CONCLUSIONS

Our data indicate high agreement between the Monolisa and Ortho tests in samples from the general population. In hemodialysis patients, however, Monolisa was more sensitive. In addition, the Monolisa test significantly reduced the window period of HCV infection.

Hepatitis C in transplant recipients of solid organs, other than liver

Hepatitis C virus (HCV) infection is prevalent in candidates for, and recipients of, solid organ transplants. HCV infection can lead to diminished patient and allograft survival in the long-term in recipients of kidney transplants. Outcomes in recipients of other solid organ transplants (lung, heart, small bowel, pancreas, pancreas-kidney) are not well established. Large, well-designed, prospective studies are needed to answer these questions. Interferon therapy for HCV before transplantation can lead to improved outcomes. Therefore, transplant candidates should be considered for and offered interferon therapy before embarking on organ transplantation. Posttransplant interferon therapy can be complicated by acute allograft rejection and is not recommended, except with advanced liver disease.

HCV-RNA qualitative assay based on transcription mediated amplification improves the detection of hepatitis C virus infection in patients on hemodialysis: results from five hemodialysis units in central Greece

BACKGROUND

End-stage renal disease patients (ESRD) on maintenance hemodialysis (HD) are at increased risk of acquiring hepatitis C virus (HCV) infection. An early and accurate diagnosis of HCV infection is important for the prevention of viral transmission and the management of ESRD patients on HD but conventional ELISA and PCR have often failed to reveal active HCV infection.

OBJECTIVES

This study evaluated the prevalence of HCV infection in ESRD patients from all HD units in central Greece using a sensitive HCV-RNA transcription mediated amplification (TMA) assay and compared its sensitivity with that of anti-HCV ELISA.

STUDY DESIGN

Anti-HCV antibody (third generation ELISA), HCV-RNA (TMA) and HCV genotypes (HCV TMA-LiPA) were determined in 366 ESRD Greek patients.

RESULTS

In total, 132 (36%) ESRD patients were HCV positive by ELISA or TMA; 44 by TMA alone, 16 by ELISA alone and 72 positive by both assays. More than half of the viraemic patients had genotype 3a.

CONCLUSIONS

HCV-RNA (TMA) assay appears to increase the accuracy in the diagnosis of HCV infection in HD patients compared to the anti-HCV ELISA and could serve as an additional screening tool in these patients.

Prolonged time until seroconversion among hemodialysis patients: the need for HCV PCR

OBJECTIVE

Patients on maintenance hemodialysis are known to have an elevated risk of acquiring hepatitis C virus (HCV) infection. Therefore, a reliable diagnosis of HCV infection is essential in order to prevent the spread of the disease in dialysis units. However, whether PCR examination is dispensable in hemodialysis patients has been debated.

METHODS

From 1995 to 2002, serum samples from all hemodialysis patients at our hospital (n = 1,774) were screened by serological assays and by polymerase chain reaction (PCR).

RESULTS

In 25 of these patients acute HCV infection was observed and in 11 patients HCV seroconversion was delayed for 3-16 months. During this time the infection was exclusively detectable by PCR.

CONCLUSION

Despite the growing demand for cost-effectiveness in the health system, HCV PCR examination must remain an essential part of the routine screening in hemodialysis patients.

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.

Novel assay using total hepatitis C virus (HCV) core antigen quantification for diagnosis of HCV infection in dialysis patients

Dialysis patients remain a high-risk group for hepatitis C virus (HCV) infection. The current diagnosis of HCV infection among dialysis patients includes serological assays and nucleic acid amplification technology (NAT) for assessing serum anti-HCV antibody and HCV viremia, respectively. However, current NAT techniques are expensive and labor-intensive and often lack standardization. An assay prototype designed to detect and quantify total HCV core antigen (total HCV core Ag) protein in serum and plasma in the presence or absence of anti-HCV antibodies has been recently developed. A comparison between a total anti-HCV core Ag enzyme-linked immunosorbent assay (ELISA) and a quantitative HCV RNA assay based on reverse transcription-PCR (RT-PCR) (Amplicor HCV Monitor test) was performed using a large (n = 305) cohort of ELISA HCV 3.0 HCV-negative and -positive patients on maintenance dialysis. The concentrations of HCV core Ag and HCV RNA levels (measured by RT-PCR) were significantly correlated (r = 0.471, P = 0.0001) over a wide range of HCV RNA levels and were maintained among different HCV genotypes (HCV genotype 1, r = 0.862, P = 0.0001; HCV genotype 2, r = 0.691, P = 0.0001). We estimated that 1 pg of total HCV core Ag per ml is equivalent to approximately 19.952 IU of HCV RNA per ml, even if the wide range in the ratio of core Ag to HCV RNA (95% confidence intervals, 2.8 x 10(3) to 1.6 x 10(5) IU/ml) precluded definitive conclusions. In summary, total HCV core Ag proved to be useful for performing HCV RNA measurement among dialysis patients in routine laboratories without the need for special equipment or training. The present study supports the use of the total anti-HCV core Ag ELISA for assessing viral load among dialysis patients with HCV infection.

Prevalence of hepatitis C virus infection among hemodialysis patients at a tertiary-care hospital in Mexico City, Mexico

We determined the prevalence of hepatitis C virus (HCV) in hemodialysis patients by antibody testing and HCV RNA determination by PCR. A total of 149 patients with kidney failure with replacement therapy were tested. The prevalence of anti-HCV was 6.7% (10 of 149 patients), and viremia was detectable in 8 of 149 (5%) patients. Three of 149 patients (2%) were anti-HCV negative with detectable HCV RNA.

Patterns of hepatitis C prevalence and seroconversion in hemodialysis units from three continents: the DOPPS

BACKGROUND

Hepatitis C virus (HCV) remains a problem within hemodialysis units. This study measures HCV prevalence and seroconversion rates across seven countries and investigates associations with facility-level practice patterns.

METHODS

The study sample was from the Dialysis Outcomes and Practice Patterns Study (DOPPS), a prospective, observational study of adult hemodialysis patients randomly selected from 308 representative dialysis facilities in France, Germany, Italy, Japan, Spain, the United Kingdom, and the United States. Logistic regression was used to model odds of HCV prevalence, and Cox regression was used to model time from study entry to HCV seroconversion.

RESULTS

Mean HCV facility prevalence was 13.5% and varied among countries from 2.6% to 22.9%. Increased HCV prevalence was associated with longer time on dialysis, male gender, black race, diabetes, hepatitis B (HBV) infection, prior renal transplant, and alcohol or substance abuse in the previous 12 months. Approximately half of the facilities (55.6%) had no seroconversions during the study period. HCV seroconversion was associated with longer time on dialysis, human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), HBV infection, and recurrent cellulitis or gangrene. An increase in highly trained staff was associated with lower HCV prevalence (OR = 0.93 per 10% increase, P= 0.003) and risk of seroconversion (RR = 0.92, P= 0.07). Seroconversion was associated with an increase in facility HCV prevalence (RR = 1.36, P < 0.0001), but not with isolation of HCV-infected patients (RR = 1.01, P= 0.99).

CONCLUSION

There are differences in HCV prevalence and rate of seroconversion at the country and the hemodialysis facility level. The observed variation suggests opportunities for improved HCV outcomes.

[High prevalence and incidence of hepatitis C virus infections among dialysis patients in the East-Centre of Tunisia]

Hemodialysed patients are recognised as a group at increased risk of infection with hepatitis C virus (HCV). The aim of this study was to determine the prevalence and incidence of HCV infection among dialysis patients of the east-centre part of Tunisia. Two hundred and seventy-six patients dialysed until 2001 were recruited within seven hemodialysis units located in the cities of Sousse, Monastir and Mahdia. The serum markers of HCV infection were tested over the period of March 2000-December 2002, by a 3rd generation ELISA test for antibodies and by qualitative RT-PCR technique for viral RNA. The prevalence of anti-HCV antibodies and of HCV RNA was 32.6% (90 patients) and 25.7% (71 patients), respectively. Between 1998 and 2002, 20 new infections were documented in five of the seven dialysis units corresponding to an incidence of 2.34% per year, with an average time of contamination after the beginning of dialysis of 4.6 years. If all the infections are assessed to have occurred during dialysis, the density of incidence of HCV contamination was 4.4% per year of dialysis. A high correlation was noticed between the presence of HCV markers in serum and the duration of dialysis (F = 34.15, P < 0.0001). In the absence of other risk factors (transfusion, drug-addiction), these results plead for the nosocomial transmission of the observed HCV infections. A phylogenetic analysis of the E2 hypervariable region of the viral genome is in progress to confirm this assumption.

Hepatitis C Infection: A Clinical Review

Nearly three million persons in the United States are viremic with hepatitis C (HCV). Despite a decreasing incidence of HCV in this country, the prevalence of HCV-related chronic liver disease is increasing. Most infections in the United States are acquired by intravenous drug use. The chronicity rate of HCV is high, reaching 85% in some populations, and the risk of progression to advanced liver disease is as high as 20% within twenty years of infection. Host factors like alcohol use accelerate the rate of progression. The enzyme immunoassay is the preferred initial test for diagnosis; the third generation assay has greater than a 99% specificity in immunocompetent patients. Barring contraindications, the standard of care for treatment of chronic HCV has become pegylated interferon and ribavirin. With this therapy, the cure rate for treatment-naïve patients is about 55%, but rates are higher in certain groups. Common side effects of therapy include neuropsychiatric symptoms, influenza-like symptoms and hematological abnormalities.

Clinical evaluation of an HIV-1 and HCV assay and demonstration of significant reduction of the HCV detection window before seroconversion

BACKGROUND

One HIV-1 and HCV assay simultaneously detects HIV-1 and HCV RNA (Procleix, Chiron Corp.). The main intended use of the assay is the testing of blood and blood products in blood banking.

STUDY DESIGN AND METHODS

To evaluate the clinical sensitivity of the assay, 164 anti-HIV-1+ and 160 anti-HCV+ patients of different viral load were tested. The assay specificity was determined in 1000 HIV-1- and HCV-seronegative blood donors. The ability of the assay to detect different HCV genotypes was investigated in a total of 40 patients of different genotypes (1-4). Furthermore, to investigate the reduction of the HCV window phase before seroconversion, serial samples of 25 hemodialysis patients who seroconverted to anti-HCV were also tested.

RESULTS

The assay detected all 60 HIV-1-infected patients with a viral load of greater than 50 copies per mL and 48 of 104 patients with a viral load of less than 50 copies per mL. Moreover, all 60 patients with an HCV RNA load of greater than 521 IU per mL and 7 of 100 patients with a viral load of less than 50 IU per mL tested positive. The assay specificity was found to be 100 percent. In addition, all 40 patients of different HCV genotypes were successfully detected. Finally, the median time that the assay detected HCV infection before second- and third-generation anti-HCV assay was found to be 183 and 91 days, respectively.

CONCLUSION

The assay sensitivity and specificity, its ability to detect different HCV genotypes, and the significant reduction of window period of HCV infection further support its use for improving the safety of blood and blood products.

Hepatitis C virus infection in dialysis and chronic liver patients: Viraemia dependent anti-E2-antibody response

Cryptic hepatitis C virus (HCV) infection relates to patients infected chronically with HCV that are seronegative but have HCV-RNA. These patients are not identified by the standard serological tests for HCV, which are based on detection of antibodies to core, NS3 and NS5 antigens. They will, therefore, be wrongly diagnosed as non-infected, and are considered as a potential risk for others. Cryptic HCV infection in dialysis units occurs frequently and, due to medical procedures, is a major factor for contracting the virus when unrecognised. This study was conducted in order to assess the humoral immune responses to E2-antigen in sera of patients infected chronically with HCV. Recombinant E2 protein in enzyme linked immunosorbent assay (ELISA) and Western blot (WB) were used to test the occurrence of anti-E2 antibodies in the sera of patients from the liver clinic and of dialysis patients. The presence of E2 antibodies was found to be correlated with the presence of HCV-RNA and with viral load. Antibodies to the E2 protein could be detected in as many as 30% of the sera from dialysis patients with cryptic HCV infection (HCV-RNA only). The results suggest that detection of anti-E2 antibodies may enhance significantly HCV serological standard testing; especially among patients on dialysis, and that antibodies to envelope E2 protein appear to depend on and correlate with the presence of HCV particles.

The impact of hepatitis c virus viremia on renal graft and patient survival: a 9-year prospective study

BACKGROUND

The impact of hepatitis C virus (HCV) infection on long-term patient and renal graft survival is controversial.

METHODS

We prospectively followed up for approximately 9 years 133 hepatitis B surface antigen (HBsAg)-negative successive renal transplant recipients for whom HCV RNA polymerase chain reaction (PCR) results were available before transplantation. We compared graft and patient survival rates and causes of death and graft failure in PCR-positive and PCR-negative transplant recipients. Cox proportional hazards models were used to detect the impact of HCV infection on patient and graft survival. We also studied posttransplantation hepatic function and graft performance.

RESULTS

HCV RNA was detected in sera of 87 patients (65%). Univariate and multivariate analyses did not show an increased risk for death or graft failure in viremic compared with nonviremic transplant recipients. However, HCV-infected transplant recipients with chronic alanine aminotransferase level elevations had increased risks for death (odds ratio, 3.7; 95% confidence interval [CI], 1 to 13.7) and graft failure (odds ratio, 3; 95% CI, 1.4 to 6.7) compared with viremic transplant recipients with persistently normal liver function test results and noninfected patients. Five viremic and no nonviremic transplant recipients died of liver disease. HCV viremic transplant recipients had significantly greater frequencies of biochemical chronic liver disease, proteinuria, and biopsy-proven chronic allograft nephropathy (CAN) compared with noninfected transplant recipients.

CONCLUSION

HCV infection per se has no adverse effect on long-term renal graft and patient survival. However, HCV-infected transplant recipients with abnormal liver function have inferior survival rates. HCV infection in renal transplants is associated with greater rates of proteinuria and CAN.

Lack of seronegative hepatitis C virus infections in patients with chronic renal failure

BACKGROUND

Recent reports have indicated that serologic testing for hepatitis C virus (HCV) in patients with chronic renal failure may be inadequate to detect infections in this patient population.

METHODS

We prospectively tested 258 patients with end-stage renal disease who were referred for evaluation for renal transplantation for anti-HCV using a second-generation enzyme immunoassay (EIA) and a second-generation qualitative reverse-transcriptase polymerase chain reaction (RT-PCR). We confirmed all positive EIAs with a third-generation recombinant immunoblot assay and genotyped RT-PCR-positive specimens.

RESULTS

We found that 22 patients (8.5%) had serological evidence of HCV infection. Nineteen (86%) of the antibody-positive patients were viremic (HCV RNA positive). All but 1 of the patients was infected with HCV genotype 1. None of the 233 HCV antibody-negative patients were shown to be viremic by RT-PCR.

CONCLUSIONS

No additional HCV cases were detected by screening all patients for HCV RNA by RT-PCR. However, RT-PCR is a valuable adjunct to serology in antibody-positive patients to distinguish resolved from active infections.

Development of an HCV infection risk stratification algorithm for patients on chronic hemodialysis

OBJECTIVE

The prevalence of hepatitis C virus (HCV) in patients on chronic hemodialysis (HD) is near 9%. Transaminases, which are lower in HD patients, are not effective in screening for HCV. Our aim was to design an HCV risk stratification strategy incorporating lowered aminotransferase levels and other clinical parameters.

METHODS

Patient serum from 168 consecutive HD patients was analyzed for AST, ALT, ferritin, and hepatitis C antibody. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for lower transaminase values. Multivariate classification and regression tree analysis was used to determine the best combination of variables to predict risk for HCV infection.

RESULTS

Median AST and ALT levels were higher in anti-HCV Ab(+) patients (p < 0.05). Applying a lower cutoff value for ALT of 16 IU/L resulted in a sensitivity of 61.1%, a specificity of 66.7%, a positive predictive value of 33.9%, and a negative predictive value of 86.0% for detection of HCV infection. Multivariate classification and regression tree analysis derived an algorithm using patient age, months on HD, and AST, resulting in a 97.2% sensitivity and a 51.9% specificity for the detection of HCV(+) HD patients.

CONCLUSIONS

A lower normal cutoff value of 18 IU/L for AST and 16 IU/L for ALT increased sensitivity and specificity for the detection of HCV infection in HD patients. An algorithm combining lower transaminases with clinical parameters improved both sensitivity and specificity in HCV detection. Prospective confirmation of this algorithm would allow more selective HCV enzyme immunoassay and polymerase chain reaction testing in dialysis units.

Hepatitis C infection and the patient with end-stage renal disease

Hepatitis C virus (HCV) remains common in patients with end-stage renal disease (ESRD) and is an important cause of liver disease in this population. Acquisition of HCV infection continues to occur in dialysis patients because of nosocomial spread. The natural history of HCV in dialysis patients remains controversial because the course of HCV typically extends over decades, whereas dialysis patients have higher morbidity and mortality rates than those of the general population limiting long-term follow-up. However, recent reports suggest that HCV infection affects the survival of chronic dialysis patients as well as renal transplant (RT) recipients. The severity of preexisting liver disease on pretransplantation liver biopsy may provide useful prognostic information about clinical outcome after RT; liver biopsy should be incorporated in the evaluation and management of RT candidates with HCV. Recent surveys with long-term follow-up have documented adverse effects of HCV on patient and graft survival. Use of renal grafts from HCV-infected donors in recipients with HCV does not appear to result in a greater burden of liver disease albeit with short-term follow-up. There is only limited data about interferon (IFN) therapy in chronic dialysis patients, although sustained responses are reported. Preliminary data on IFN plus ribavirin therapy in dialysis patients with hepatitis C have given encouraging results, but randomized trials are needed. Interferon remains contraindicated post-RT because of concern about precipitating graft dysfunction.

Hepatitis C virus infection in renal failure patients in the absence of anti-hepatitis C virus antibodies

The magnitude and clinical significance of Hepatitis C virus (HCV) infection in dialysis patients is controversial and underestimated. This study was conducted in order to evaluate the correlation between HCV replication and antibody response to HCV in dialysis patients. HCV infection in dialysis patients was evaluated over a period of 3 years and compared to HCV infection in Liver Clinic patients. Sera were collected from 310 dialysis patients and tested for anti-HCV and HCV-RNA. In addition, HCV genotype and HCV viral load were determined in HCV-RNA-positive sera. Anti-HCV was detected in 43 (14%) of the dialysis patients. Of these, 37 (86%) were HCV-RNA-positive. Among the 267 HCV-seronegative dialysis patients, 25 (9%) were found to be HCV-RNA-positive in more than one sample during the study. These patients were characterized by low viral load; at least two orders of magnitude lower than in the group of HCV-seropositives. In contrast, in the Liver Clinic patients, HCV-RNA was found exclusively in HCV-seropositive patients. Comparison of the genotype pattern in the two groups did not reveal a difference. Our results suggest that HCV infection in dialysis units may be underestimated due to cases of low viral load, depending on the method of RNA extraction and sensitivity of the test used. Low viral load might contribute to the lack of humoral immune response seen in some dialysis patients.

Detection and prevention of hepatitis C in dialysis patients and renal transplant recipients. A long-term follow up (1989-January 1997)

BACKGROUND

Hepatitis C is frequent problem in dialysis wards.

DESIGN

A long time (1989-97) follow up of hepatitis C virus (HCV) infection in a Swedish nephrology unit was performed with anti-HCV screening, confirmatory antibody tests, viral RNA detection and molecular characterization. Case histories were reviewed with focus, onset of infection, liver morbidity and mortality.

RESULTS

In October 1991, 10% (19 of 184) of the patients in the unit (haemodialysis-, peritoneal dialysis and transplanted patients) were verified or suspected HCV carriers, whilst the number at the end of 1996 was 8%, (13 of 157). Most patients were infected before 1991 but only in one case from a known HCV-infected blood donor. No new HCV infections associated with haemodialysis occurred during the study period. A total of 13 of 24 viremic patients had HCV genotype 2b, a pattern suggesting nosocomial transmission. This was further supported by phylogenetic analysis of HCV viral isolates in seven. HCV viremia was also common in patients with an incomplete anti-HCV antibody pattern as 8 of the 12 indeterminant sera were HCV-RNA positive.

CONCLUSIONS

Awareness, prevention, identification of infected patients and donor testing limited transmission. Indeterminant recombinant immunoblot assays (RIBA)-results should be regarded with caution as a result of the relative immunodeficiency in uremic patients. Our data indicate nosocomial transmission in several patients.

Hepatitis C virus infection and renal transplantation

With the success of organ transplantation, liver disease has emerged as an important cause of morbidity and mortality of renal transplant (RT) recipients. Numerous studies performed during the 1990s have shown that hepatitis C virus (HCV) infection is the leading cause of chronic liver disease among RT recipients. The transmission of HCV by renal transplantation of a kidney from an HCV-infected organ donor has been shown unequivocally. Liver biopsy is essential in the evaluation of liver disease of RT recipients, and histological studies have shown that HCV-related liver disease after renal transplantation is progressive. The outcome of HCV-related liver disease is probably more aggressive in RT recipients than immunocompetent individuals. Various factors can affect the progression of HCV in the RT population: coinfection with hepatitis B virus, time of HCV acquisition, type of immunosuppressive treatment, and concomitant alcohol abuse. The role of virological features of HCV remains unclear. The natural history of HCV infection after renal transplantation is under evaluation; however, recent surveys with long follow-ups have documented adverse effects of HCV infection on patient and graft survival in RT recipients. Use of renal grafts from HCV-infected donors in recipients with HCV infection does not appear to result in a greater burden of liver disease, at least for a short period. The association between HCV and de novo or recurrent glomerulonephritis after RT has been hypothesized and is an area of avid research. Reported studies do not support interferon (IFN) treatment for RT recipients with chronic hepatitis C because of the frequent occurrence of graft failure, and information on the use of other types of IFN or combined therapy (IFN plus ribavirin or amantadine) is not yet available in the RT population.

Decreased serum aminotransferase activity in patients with chronic renal failure: impact on the detection of viral hepatitis

Hepatitis C virus (HCV) infection is common in the dialysis population and patients with chronic renal failure (CRF) not requiring dialysis. HCV is the most important cause of chronic liver disease in dialysis patients; however, its role has been underestimated by the lower aminotransferase activity in the dialysis population. Aminotransferase activity in patients with CRF not requiring dialysis has not been adequately addressed to date. The aim of this study is to investigate whether serum aminotransferase levels in predialysis patients with CRF are less than those obtained in healthy individuals and dialysis patients. We also analyzed the potential association between serum aminotransferase activity and demographic, clinical, and biochemical parameters. Aspartate (AST) and alanine aminotransferase (ALT) activity was greater in antibody to hepatitis C (anti-HCV)-positive than anti-HCV-negative patients with CRF not requiring dialysis (AST, 32.3 +/- 19 versus 18.1 +/- 8 IU/L [P = 0.0001]; ALT, 32.9 +/- 28 versus 17.7 +/- 11 IU/L [P = 0.00001], respectively). Predialysis patients with CRF had lower AST and ALT activity in comparison to healthy individuals (AST, 19.7 +/- 11.2 versus 20.4 +/- 6.8 IU/L [P = 0.00001]; ALT, 19.5 +/- 15.1 versus 21.7 +/- 11.3 IU/L [P = 0.00001], respectively). The difference was much greater after correction for viral markers: AST and ALT levels in hepatitis B surface antigen (HBsAg)-negative anti-HCV-negative predialysis patients with CRF were less than those in the healthy population (AST, 17.9 +/- 8 versus 20.4 +/- 6.8 IU/L [P = 0.00001]; ALT, 17.5 +/- 10 versus 21.7 +/- 11.3 IU/L [P = 0.00001], respectively). Comparison of AST and ALT activity between age-matched healthy and predialysis seronegative CRF groups showed lower AST and ALT values in the study population. HBsAg-negative anti-HCV-negative dialysis patients had lower AST and ALT activity than seronegative predialysis patients with CRF (AST, 16.6 +/- 11.6 versus 17.9 +/- 8 IU/L [P = 0.01]; ALT, 16.3 +/- 9.4 versus 17.5 +/- 10 [P = 0.041], respectively). Multivariate analysis in the predialysis CRF population showed an independent association between AST (P = 0.00001) and ALT (P = 0.00001) activity and anti-HCV positivity, and age was negatively linked to AST (P = 0.011) and ALT levels (P = 0.001). AST level was negatively related to serum creatinine level (P = 0.0001). In conclusion, HCV infection causes significant liver injury in predialysis patients with CRF. These patients have decreased aminotransferase activity compared with the general population. Dialysis patients show lower aminotransferase activity than predialysis patients with CRF. Because serum aminotransferase levels are commonly used to screen for liver disease in the dialysis and predialysis CRF population, recognition of liver damage may be hampered by the reduction in aminotransferase values in these patients. Studies aimed to clarify the pathogenesis of this phenomenon are in progress.