Hepatitis C infection in two urban hemodialysis units

The world prevalence, associated risk factors and mortality of hepatitis C virus infection in hemodialysis patients: a meta-analysis

BACKGROUND

The worldwide burden of HCV infection among hemodialysis patients has not been systematically examined.

METHODS

A systematic literature search was conducted in MEDLINE and Scopus to determine the worldwide prevalence of HCV infection, risk factors, and clinical outcomes among hemodialysis patients. Random-effect models and meta-regressions were used to generate pooled estimates and assess heterogeneity.

RESULTS

Four hundred and seven studies with 1,302,167 participants were analyzed. The pooled prevalence of HCV infection was 21%. The highest prevalence was observed in Africa (28%) and low-income countries (48.5%). A significant prevalence decline was observed following the publication year and was also inversely related to GDP and total population of each country. Factors associated with HCV positivity included younger age, longer dialysis duration, more blood transfusions, and dialyzer reuse. The pooled unadjusted hazard ratio for all-cause mortality was 1.12 (95% CI 1.03-1.22), and the adjusted hazard ratio was 1.21 (95% CI 1.12-1.30) in HCV-infected compared to non-HCV infected patients.

CONCLUSIONS

HCV infection among hemodialysis patients is a worldwide shared burden and is associated with a higher risk of death. Avoiding unnecessary blood transfusion and dialyzer reuse should be encouraged to prevent HCV transmission in hemodialysis units.

Prevalence of Hepatitis c Antibodies (HCV) in a Dialysis Population at One Center

Hepatitis C (HC) has been recently diagnosed by determination of specific antibodies that represent the former so-called non-A, non-B hepatitis.

We studied the prevalence of plasma HCV antibodies among 61 unselected patients on hemodialysis (HD) and 43 on continuous ambulatory peritoneal dialysis (CAPD). Plasma C-antibodies were determined through the ELISA test system. Transfusion policy was the same in both groups.

The prevalence of hepatitis C virus antibodies was significantly higher in hemodialysis patients than among those on CAPD. Time on dialysis, previous blood transfusions, and renal transplantation seem to increase the prevalence of C hepatitis antibodies among hemodialy sis patients. The effect of these parameters on CAPD was smaller. Understanding the reasons for these differences may help prevent this disease among dialysis patients.

The Need for Second-Generation Antihepatitis C Virus Testing in Uremic Patients on Continuous Ambulatory Peritoneal Dialysis

Objective

To assess the prevalence and clinical relevance of a hepatitis C virus (HCV) infection in continuous ambulatory peritoneal dialysis (CAPD) patients by first (Ortho) and second-generation (Abbott and UBI) HCV antibody enzyme immunoassays.

Design

Thirty-two serum samples tested by first generation HCV antibody enzyme immunoassays (EIA's) were reevaluated using two second-generation HCV antibody EIA's. Basic demographic data, history of blood transfusions, and duration of hemodialysis and CAPD were reviewed. Results were analyzed by chi square analysis, Wilcoxon rank sum, and the paired t-test.

Setting

The medical college's affiliated teaching hospital.

Results

The prevalence of the antibody anti-HCV increases with the duration of previous hemodialysis, but not with the duration of CAPD. The positive detection of anti-HCV by second-generation HCV antibody EIA's was higher than first-generation EIA's (25% and 34.4% vs 12.5%).

Conclusion

The prevalence and clinical relevance of HCV infection can be more accurately studied using the second-generation assays in uremic patients.

Prevalence of Hepatitis C Antibodies (HCV) in a Dialysis Population at One Center

Hepatitis C (HC) has been recently diagnosed by determination of specific antibodies that represent the former so-called non-A, non-B hepatitis.

We studied the prevalence of plasma HCV antibodies among 61 unselected patients on hemodialysis (HD) and 43 on continuous ambulatory peritoneal dialysis (CAPD). Plasma C-antibodies were determined through the ELISA test system. Transfusion policy was the same in both groups.

The prevalence of hepatitis C virus antibodies was significantly higher in hemodialysis patients than among those on CAPD. Time on dialysis, previous blood transfusions, and renal transplantation seem to increase the prevalence of C hepatitis antibodies among hemodialy sis patients. The effect of these parameters on CAPD was smaller. Understanding the reasons for these differences may help prevent this disease among dialysis patients.

Hepatitis C Antibodies in Patients on Peritoneal Dialysis: Prevalence and Risk Factors

Our objective was to determine the prevalence of the antibody to hepatitis C (anti-HCV) in a population of endstage renal failure patients on continuous peritoneal dialysis (CPD) and study the possible risk factors associated with anti-HCV seropositivity and seroconversion. A cross-sectional study included 155 adult patients enrolled in the CPD program in a single renal unit of a teaching hospital who were screened for anti-HCV by second-generation enzyme immunoassay, which was confirmed by recombinant immunoblot assay. Serum was also assayed for hepatitis B surface antigen (HBsAg). History of renal transplantation, blood transfusions, and exposure to hemodialysis was obtained from medical records.

Ten of 155 patients (6.5%) in this study population were anti-HCV positive [anti-HCV(+)] and 11/155 (7.1%) were HBsAg positive; no patient was positive for both. All the anti-HCV(+) patients were on continuous ambulatory peritoneal dialysis (CAPD); no continuous cycling peritoneal dialysis (CCPD) patient was anti-HCV(+). Exposure to hemodialysis was a risk factor for anti-HCV seropositivity, with 7 out of 10 (70%) anti-HCV(+) patients having been on hemodialysis compared to 55/134 (41%) anti-HCV(-) (p < 0.05, Fisher's exact test). No difference was noted between anti-HCV(+) and anti-HCV(-) groups in relation to age, gender, duration on CPD, renal transplantation, or exposure to blood transfusions. Seroconversion occurred in only one patient after a mean observation period of 20±0.6 months.

The prevalence of anti-HCV seropositivity in this population of CPD patients is 6.5%, and HBsAg is 7.1%. Exposure to hemodialysis is a significant risk factor for development of anti-HCV seropositivity. Seroconversion rate appears to be low.

The prevention of hepatitis C virus transmission to hemodialysis patients and staff members

In this review article, we cover 4 topics very relevant to those involved in the care of hemodialysis (HD) patients and in the management of a HD unit. We start with an overview of the progress made over the last 25 years to reduce hepatitis C virus (HCV) transmission in HD. Next, we discuss the potential strategies to prevent the residual ongoing transmission of HCV to HD patients. Third, we discuss the actions to be taken if a seroconversion for HCV is nevertheless detected in a HD patient. Finally, we briefly discuss how best to protect HD staff members from occupationally acquired HCV infection.

Hemodialysis-Associated Infections

Hemodialysis patients are at increased risk of infections, which are common adverse events among this patient population. We review factors contributing to infections among hemodialysis patients and epidemiology of common infections and outbreaks, including bloodstream infections, vascular access infections, and infections caused by bloodborne pathogens. Recommendations for prevention are discussed with emphasis on essential infection control practices for hemodialysis settings.

Transmission of hepatitis C virus in the dialysis setting and strategies for its prevention

Hepatitis C virus (HCV) infection is more common among hemodialysis patients than the general population and transmission of HCV in dialysis clinics has been reported. In the context of the increased morbidity and mortality associated with HCV infection in the end stage renal disease population, it is important that dialysis clinics have processes in place for ensuring recommended infection control practices, including Standard Precautions, through regular audits and training of the staff. This review will summarize the epidemiology of HCV infection and risk factors for HCV transmission among hemodialysis patients. In addition, the proper protocols are required to investigate suspected cases of HCV transmission in dialysis facilities and recommendations for prevention of HCV transmission in will be reviewed.

The association of hepatitis C infection with the onset of CKD and progression into ESRD

Hepatitis C virus (HCV) infection is not only an important cause of chronic liver disease, but extrahepatic manifestations are common and include chronic kidney disease (CKD). HCV is classically associated with cryoglobulinemic glomerulonephritis in the context of mixed cryoglobulinemia syndrome, but other glomerular diseases also occur and may be significantly under-recognized. HCV may cause glomerular disease by immune complex deposition; however, other potential mechanisms by which HCV promotes CKD include a direct cytopathic effect of the virus on renal tissue, and by its association with accelerated atherosclerosis, insulin resistance, and chronic inflammation. Epidemiologic studies show HCV infection confers an increased risk of incident CKD and accelerates progression of CKD to end-stage renal disease (ESRD) in the general population, as well as subpopulations including diabetic patients, those coinfected with human immunodeficiency virus (HIV), and kidney transplant recipients. Patients with CKD and HCV infection experience inferior clinical outcomes, including poorer quality of life and an increased risk of mortality. Treatment with interferon-based regimens is associated with decreased risk of incident CKD and ESRD, though prior studies are limited by the small number of patients with HCV and CKD who underwent treatment. With the advent of new, well-tolerated direct-acting antiviral combinations that are not cleared by the kidneys, it is possible to treat all genotypes of HCV infection in patients with CKD and ESRD. More data on the effect of direct-acting antivirals on CKD incidence and progression are necessary. However, there is every expectation that with improved access to HCV treatment, the burden of CKD in patients with HCV could significantly decline.

Epidemiology of Hepatitis C Virus: A Battle on New Frontiers

The hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality in the United States and other parts of the world. The epidemiology of the disease is highly variable between and within countries, and strategies to deal with HCV identification and treatment must be tailored to the geographic location and the political and economic environment of the region. Although great strides have been made in improving HCV transmission risk in blood supply products, new challenges related to changing patterns of disease incidence continue to require fresh evaluation and new approaches to disease prevention.

Analysis of risk factors associated with hepatitis B and C infection in correctional institutions in British Columbia

The factors associated with infection with hepatitis B (hbv) and C viruses (hcv) were studied in residents of correctional institutions in British Columbia. Four hundred and fifteen residents volunteered to participate in this study. Among 415 residents tested, 28% were positive for hvb or hcv markers. Sixty-five per cent of the residents positive for hbv markers were also infected with hcv. However, in hbv-negative residents, only 14% were positive for antibody to hcv (anti-hcv). The highest rates for hbv and hcv were in 25- to 44-year-old residents. The analysis of risk factors and infection predictors in 354 residents showed that intravenous drug use and history of hepatitis were associated with infection with both hbv and hcv. The relative risk for hbv in intravenous drug users was 4.4 times that in nonusers; for hcv relative risk was 3.4 times. In the group with history of hepatitis, the relative risk was 6.2 and 4.5 times for hbv and hcv, respectively. The multivariate analysis of the data showed that both intravenous drug use and a history of hepatitis were significant (P<0.0001). Tattooing or history of transfusion was not associated with increased risk for hcv, but tattooing and age were significant factors for hbv.

Prevalence of hepatitis B in haemodialysis nursing staff in Athens

BACKGROUND

Healthcare workers are at high risk of acquiring hepatitis B and particularly haemodialysis staff. The aim of the study was to examine the prevalence of hepatitis B markers in haemodialysis nurses and to explore the determinants of the infection.

PATIENTS AND METHODS

Two hundred and sixteen haemodialysis nurses from 20 haemodialysis units in Athens completed an anonymous questionnaire, their blood samples were taken and tested for hepatitis B virus (HBV) markers.

RESULTS

The prevalence of positive HBsAg among nurses was 0.5%. Anti-HBc positivity due to past exposure to HBV was 12.5%. A total of 87.5% of the participants had immunity to HBV. Multivariate analysis demonstrated that previous exposure to HBV was related positively with the age of the haemodialysis nursing staff [odd ratios (OR): 1.115, 95% CI: 1.014-1.226, P = 0.025].

CONCLUSION

The prevalence of HBV in the haemodialysis nursing staff in Athens is low, the vaccination coverage and the immunity to HBV are high in comparison to previous reports.

Hepatitis C virus antibodies and other markers of blood-transfusion-transmitted infection in multi-transfused Cuban patients

BACKGROUND

HCV was initially identified in 1989 when it was found to be the primary causative agent of non-A, non-B hepatitis,a condition associated with high rates of progressive and end-stage liver disease, cirrhosis, and hepatocellular carcinoma. Since then, appreciation of the significant worldwide health impact of HCV infection has grown. HCV infection was identified as a public health problem in Cuba in the 1990s. Despite universal blood donor screening, which was achieved in 1995 using the Cuban immunoassay system UMELISA HCV, the infection is still found in multi-transfused patients.

OBJECTIVES

To determine the magnitude of HCV, HBV and HIV-1&2 infections among Cuban blood recipients and to assess the role of potential risk factors.

STUDY DESIGN

Cross-sectional study of 318 patients from Havana City, Pinar del Río and Villa Clara, who had been previously treated with 10 or more units of allogenic blood or blood components in at least two different occasions. The patients were evaluated for HCV Ab, HBsAg, anti-HBc Ab, and HIV-1&2 Ab. Data management and statistical analysis were performed using EpiInfo and SSPS software.

RESULTS

Prevalence rates were 51.6% for HCV Ab; 5.3% for HBsAg; 45.0% for anti-HBc and 0% for HIV-1&2 Ab. Ten (3.1%) patients were co-infected with HCV and HBV Blood transfusion was not identified as the main risk factor for HCV transmission. The number of blood units received by the patients was not statistically associated with the HCV Ab prevalence.

CONCLUSIONS

Infection with HCV was identified more frequently than HBV and HIV among our study population. Patients undergoing hemodialysis were at the highest risk of becoming infected. Medical procedures including surgery, transplantation, invasive odontology, and sharing or reuse of needles and syringes, are associated with higher HCV Ab seroprevalences compared with blood transfusion alone.

Hepatitis C infection is acquired pre-ESRD

BACKGROUND

Hepatitis C is more prevalent in patients with end-stage renal disease (ESRD) than in the general population. Previously, infection from nosocomial sources was an important cause for this increase. In the past decade, the risk from these sources has lessened, but the estimated percentage of patients with ESRD with hepatitis C virus (HCV) antibody (anti-HCV) has not changed.

METHODS

This is a prospective observational study of hemodialysis patients in 4 urban units in Birmingham, AL. Testing for anti-HCV was performed at the initiation of dialysis therapy and then yearly from August 1998 through August 2004. Race, sex, age, ESRD date, comorbid conditions, and outcomes were recorded.

RESULTS

The prevalence of anti-HCV was 16.8% in 860 patients (89% black). Patients new to ESRD had a prevalence of 14.4%. Seroconversion in previously anti-HCV-negative patients was 2.5%. Anti-HCV occurred in black men 3 times more than in black women (odds ratio, 3.3; 95% confidence interval, 2.2 to 5.0). Mean age at ESRD was significantly younger in anti-HCV-positive than HCV-negative patients (47.3 versus 54.1 years; P < 0.0001). Age, race, sex, and history of drug abuse were predictors of anti-HCV positivity.

CONCLUSION

The prevalence of anti-HCV among patients with ESRD varies from community to community. New patients are major contributors to the prevalence of anti-HCV in patients with ESRD, particularly those who are younger, male, black, or have a history of drug use. Measuring anti-HCV levels in patients with chronic kidney disease may help identify those at risk for additional disorders.

High prevalence of hepatitis C infection among patients receiving hemodialysis at an urban dialysis center

OBJECTIVE

To determine the seroprevalence and risk factors for hepatitis C virus (HCV) infection among patients at an urban outpatient hemodialysis center.

METHODS

This was a cross-sectional study of 227 patients undergoing hemodialysis at the Rogosin Kidney Center on December 15, 1998, with a response rate of 90% (227 of 253). Laboratory records were used to retrieve the total number of blood transfusions received and serologic study results. Univariate and multivariate analyses were used to examine the relationship among HCV serostatus, patient demographics, and HCV risk factors (eg, intravenous drug use [IVDU], intranasal cocaine use, multiple sexual partners, comorbidities, length of time receiving hemodialysis, and total number of blood transfusions received).

RESULTS

The seroprevalence of antibody to HCV (anti-HCV) was 23.3% (53 of 227) in the population. In univariate analysis, factors associated with HCV seropositivity included male gender, younger age, history of IVDU, history of intranasal cocaine use, history of multiple sexual partners, human immunodeficiency virus coinfection, increased time receiving dialysis, history of renal transplant, and positive antibody to hepatitis B core antigen. Multivariate logistic regression analysis showed that longer duration receiving dialysis and a history of IVDU were the only risk factors that remained independently associated with HCV seropositivity

CONCLUSIONS

HCV is markedly more common in our urban cohort of patients receiving hemodialysis compared with patients receiving dialysis nationally and is associated with a longer duration of receiving dialysis and a history of IVDU. Stricter and more frequent enforcement of universal precautions may be required in hemodialysis centers located in areas with a high prevalence of HCV infection or IVDU among the general 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.

[Antibodies to hepatitis C virus in patients undergoing hemodialysis in Salvador, BA, Brazil]

BACKGROUND

Hepatitis C infection in hemodialysis units has been evaluated in different geographic regions.

AIMS

The prevalence of anti-HCV in patients undergoing hemodialysis program in the city of Salvador, State of Bahia, Brazil, was studied and its association with transfusions, duration of hemodialysis and ALT elevation.

METHOD

During a period of 17 months, all patients undergoing dialytic treatment, were evaluated. The total number of patients was 395, all of whom completed a questionnaire and provided serum samples for laboratory analysis. Serological levels were measured for ALT and the samples were tested for anti-HCV using ELISA II with a further confirmation using RIBA III.

RESULTS

Anti-HCV was positive in 23.8% (94/395). The presence of transfusions was associated with anti-HCV and as the number of transfusions used increased, so did the frequency of anti-HCV. Of the patients who never received transfusions, 12.5% (6/48) were anti-HCV positive. The duration of dialytic treatment lasted from 53.44 +/- 36.45 months in the anti-HCV positive group and 22.10 +/- 22.75 months for the group testing negative. ALT elevation was more frequent in the anti-HCV positive group. Positivity for the RIBA III fractions was 79.8%, 100%, 80.9% and 52.1%, for c100-3, c33, c22 and NS5, respectively. The anti-NS5 was even less frequent in the group with elevated ALT.

CONCLUSIONS

The prevalence of anti-HCV in patients undergoing chronic hemodialysis in Salvador, Bahia, is elevated and it is associated with transfusions, a longer duration of dialytic treatment and ALT elevation.

Histopathological features of hepatitis C in renal transplant candidates [see comment]

BACKGROUND

Although hepatitis C virus (HCV) infection is common in renal transplant candidates, its clinical significance remains unclear in this population. Little detailed information is available about the histological severity of HCV infection in these patients. We evaluated the liver biopsy features of chronic HCV in a large population of renal transplant candidates and investigated associations between histopathological changes and host- and virus-related factors.

METHODS

Thirty-seven patients seropositive for anti-HCV with chronic renal failure (CRF) referred to UCLA Medical Center for kidney or kidney/liver transplantation during the period 1992-1997 were included. HCV genotype and viral load were measured. A multivariate analysis by logistic regression model was performed: age, gender, race, HCV load and genotype, CRF level, aspartate and alanine aminotransferase activity, duration of HCV infection, underlying nephropathy, and alcohol abuse were independent variables; liver histology score was assumed a dependent variable.

RESULTS

Liver disease was present in all HCV-infected patients. Logistic regression analysis revealed that histological damage was (P = 0.0017) independently associated with the CRF level; the severity of liver disease, as shown by univariate analysis, being significantly higher in CRF patients not requiring dialysis than among dialysis population. All patients on dialysis showed mild or moderate necroinflammatory activity; the majority (22/28 = 79%) of these individuals had fibrosis, three (3/28 = 11%) dialysis patients had established cirrhosis. Thirty-one (84%) of 37 patients were tested by polymerase chain reaction, 25 (81%) patients had detectable HCV RNA in serum, the mean HCV load among viremic patients was 10.9x10(5) copies/ ml. The most frequent HCV genotypes were la (8/24 = 33%) and 1b (7/24 = 29%), followed by genotype 2b (3/24 = 12%).

CONCLUSIONS

Pathological changes on liver biopsy were observed in all HCV-infected patients awaiting renal transplantation. The severity of histologic damage observed on liver biopsy was less in dialysis than predialysis CRF patients. All dialysis patients had mild or moderate necroinflammatory activity; fibrosis was frequent with 11% of them having cirrhosis. The HCV viral load was rather low; no relationship between liver histology changes and virological features of HCV or aminotransferase activity was apparent. Further studies with repeat liver biopsies after kidney transplantation to observe the evolution of HCV-related liver disease after immunosuppressive therapy are indicated. We suggest including liver biopsy in the evaluation of the HCV-infected renal transplant candidate.

Biological dynamics of viral load in hemodialysis patients with hepatitis C virus

The biological dynamics of hepatitis C virus (HCV) viremia in uremic patients with chronic infection have not been fully characterized. We prospectively studied fluctuations of HCV-RNA in sera from 52 patients with end-stage renal disease who were undergoing maintenance hemodialysis (HD) and had chronic HCV infection. We measured HCV viremia monthly over the course of 13 months with the branched-chain DNA (bDNA) signal amplification assay and prospectively analyzed liver function, expressed by monthly serum aspartate (AST) and alanine aminotransferase (ALT) determinations. We observed three different patterns of HCV viremia: (1) patients persistently positive by bDNA assay (persistent viremia; 23 of 52 patients; 44%), (2) individuals with alternatively positive and negative results (intermittent viremia; 17 of 52 patients; 33%), and (3) patients persistently negative by bDNA assay (12 of 52 patients; 23%). The HCV viral load over the follow-up was greater among patients with persistent compared with intermittent viremia (persistent, 31.7 x 10(5) Eq/mL; range, 6.3 x 10(5) to 16.03 x 10(6) Eq/mL versus intermittent, 10.4 x 10(5) Eq/mL; range, 1.1 x 10(5) to 9.4 x 10(6) Eq/mL; P = 0.0001). In addition, patients with persistent viremia had over time greater AST and/or ALT activities than the intermittent group (AST: persistent, 26.5 IU/L; range, 9.6 to 73.7 IU/L versus intermittent, 21.3 IU/L; range, 8 to 56.8 IU/L; P = 0.001 and ALT: persistent, 14.7 IU/L; range, 3.7 to 57.9 IU/L versus intermittent, 10.9 IU/L; range, 2.3 to 52.1 IU/L; P = 0.001). In the group with persistent viremia, the mean difference between maximum and minimum values of HCV-RNA observed in each individual patient was 2.09 +/- 0.7 natural logarithm (Log(n)) and in intermittent viremic patients, 1.55 +/- 1 Log(n) (P = 0.045). The HCV load at study entry (19.4 x 10(5) Eq/mL) was rather low and did not change versus the end of follow-up in all patients (P = not significant [NS]). In the entire group, the fluctuations in HCV-RNA levels over time between and within individuals were not significant (P = NS). No difference in variability of HCV-RNA values over time between patients infected with different HCV genotypes was seen. In conclusion, three different patterns of HCV viremia in HD over time were assessed; one third of viremic patients had intermittent viremia, and those patients had less HCV-RNA, enzyme-linked immunosorbent assay, and aminotransferase activity than did patients with persistent HCV load. Larger fluctuations in HCV RNA levels occurred in patients with persistent than with intermittent HCV viremia. However, the viremic HCV load was low and relatively stable over a 13-month follow-up in our population. Studies with longer observation periods are warranted to understand fully the natural history of HCV in these immunosuppressed individuals.

Automated specific capture of hepatitis C virus RNA with probes and paramagnetic particle separation

We developed and evaluated a prototype automated specimen preparation instrument for the specific capture of hepatitis C virus (HCV) RNA with probes and magnetic bead-fluid separation. HCV RNA was isolated from serum by lysis of virus particles with a chaotropic agent, followed by hybridization of the RNA with biotinylated probes and capture of the hybridized RNA with streptavidin-coated paramagnetic particles. After washing of the hybrid-particle complexes to remove nonspecifically bound materials, the particles were resuspended in a specimen diluent and were then ready for amplification and detection with a fully automated PCR system (COBAS AMPLICOR; Roche Diagnostic Systems). The analytical sensitivity in the dilution series was 33 copies per ml or greater. Comparison of the test results with those obtained by a manual method based on organic extraction and precipitation of RNA (SepaGene RV-R; Sanko Junyaku Co., Ltd.) showed 93% (49 of 53 samples) sensitivity and 100% (12 of 12 samples) specificity. There was 94% overall agreement between results. When RNA was extracted by the manual method from serum containing 10(3) or 10(5) copies of HCV per ml in the presence of heparin, there was an inhibitory effect on detection of both HCV RNA and the internal control. In contrast, when RNA was extracted from the serum by the automated method, there was no inhibitory effect. This inhibitory effect of heparin on the manual method was also observed for a series of serum specimens from a hemodialysis patient, but the inhibitory effect was eliminated by the automated specimen preparation method. In summary, a fully automated RNA extraction system for PCR detection of HCV RNA by use of specific capture with probes and magnetic bead-fluid separation was shown to have performance similar to that of the conventional manual method. In addition, it successfully eliminated the inhibitory effect of the heparin in the serum and permitted the detection of HCV RNA in serum samples from a hemodialysis patient. The prototype automated RNA extraction system is suitable as a totally automated system, starting with RNA extraction to detection of HCV, if it was combined with the fully automated COBAS AMPLICOR PCR system.

Hepatitis C virus infection in dialysis: a continuing problem

Patients on chronic dialysis are at increased risk of acquiring parenterally transmitted hepatitis viruses from blood product transfusions or nosocomial transmission in hemodialysis units, and biochemical abnormalities in liver function are seen in 10-44% of patients on chronic hemodialysis. In the past, hepatitis B virus (HBV) was the major cause of parenterally transmitted viral hepatitis in dialysis patients, and the remaining cases were attributed to non-A, non-B hepatitis (NANBH). The discovery of the hepatitis C virus (HCV) has shed light on the cause and clinical course of NANBH in patients on dialysis. The current debate is focused on strategies to reduce the transmission of HCV among dialysis patients and to lessen the consequences of liver disease among patients already infected.

Prospective follow-up study of hepatitis C virus infection in patients undergoing maintenance haemodialysis: comparison among haemodialysis units

A prospective follow-up study on hepatitis C virus (HCV) infection was conducted in seven haemodialysis units from April 1990 to March 1995. A total of 634 patients were undergoing maintenance haemodialysis in the seven units. Of those, 302 patients participated in the follow-up study; 179 were initially HCV antibody negative and 123 were initially positive. Nine of the 179 initially negative patients became positive for HCV antibody during the follow-up period. In accordance with the appearance of HCV antibody, indicating new infection of HCV, all nine of these patients were diagnosed with HCV viraemia. As no other routes were apparent, HCV infection in all nine patients was likely due to nosocomial transmission. Prevalence of HCV antibody at the start of follow up was significantly higher (P < 0.001) in haemodialysis units A-C (37.9%) than in haemodialysis units D-G (17.0%). Incidence of new HCV infection was significantly higher (P = 0.005) in the former units (2.2% per year) than in the latter (0.2% per year). Ten of the 123 patients who were initially positive for the HCV antibody exhibited a loss of reactivity during the follow-up period; of these 10 patients, nine were negative for HCV-RNA from the start of the study. In conclusion, the incidence of new HCV infection seen in patients undergoing haemodialysis suggests that their risk of acquiring HCV infection is directly related to the prevalence of HCV antibody positive patients being treated in the units.

Prospective virological follow-up of hepatitis C infection in a haemodialysis unit

Hepatitis C virus (HCV) is of major concern in the management of patients on maintenance haemodialysis. Many studies have reported a high prevalence of HCV infection in dialysis centres. The objective of our study was first, to perform a prospective follow-up of the evolution of HCV infection in a haemodialysis centre, and second, to assess the rate of viral clearance in patients on dialysis. For this, genotypes, HCV antibodies (anti-HCV) and HCV RNA were evaluated initially and 9 months later. HCV RNA quantification was also performed. Of 136 patients, 62 (45.6%) were anti-HCV positive by third-generation enzyme immunoassay (EIA 3) in the first survey and 64 of 136 (47.1%) were anti-HCV positive by EIA 3 in the second survey. The rate of new HCV infection, estimated from the two seroconversions between the surveys, was 1.9% per year. One of the two patients was initially HCV RNA positive, with a titre of 0.6 x 10(6) eq ml-1. The viral load measured in the dialysis patients was low and does not seem to be influenced by dialysis. No significant difference was observed in viral load between the two periods nor were there any gender-related differences in viral load. In conclusion, detection of antibodies to HCV, together with HCV RNA, seems to be relevant in haemodialysis patients, but this strategy is not suitable for use in all haemodialysis centres because of its high cost.

Adsorption of hepatitis C virus particles onto the dialyzer membrane

It was recently found that the blood level of hepatitis C virus (HCV) RNA is significantly reduced after each dialysis procedure in patients on chronic hemodialysis. This study was designed to elucidate the mechanism for this phenomenon. In two patients with high serum levels of HCV RNA, the filtrate through the dialyzer (TF-alpha, Teijin Co., Tokyo, Japan) was analyzed for viral RNA using the polymerase chain reaction. At the end of dialysis, the filter was washed with saline, and during the saline washing, aliquots were taken for quantification of RNA by the branched DNA method. The HCV core antigen was quantified as a measure of viral particles, and hemoglobin was also measured for correcting for blood contamination. After the clearance of the blood, the filter was washed with guanidinium isothiocyanate, and the recovery of RNA was measured. The filtrate did not contain detectable RNA. The saline washing of the filter after dialysis contained a significant amount of RNA. Washing with guanidinium isothiocyanate of the thoroughly saline washed filter also recovered a significant amount of RNA. During saline washing, the recovery of RNA in the washing was much delayed behind that of hemoglobin, suggesting the adsorption of the former onto the filter membrane. There was a discordant recovery of RNA and HCV core antigen in the washing, the recovery of the former being delayed behind that of the latter. These results indicate that viral particles are adsorbed onto the inner surface of the filter membrane during dialysis. Some of these adsorbed viral particles are perhaps destroyed by hydraulic pressure applied to blood for dialysis.

Hepatitis in patients with end-stage renal disease

Hepatitis B and hepatitis C are two common pathogens causing chronic hepatitis in patients with end-stage renal disease (ESRD). With the acceptance of hepatitis B s antigen (HBsAg) screening, infected patients have been identified and isolated over the past 20 years. Consequently, hepatitis B is now being seen less frequently in dialysis units. Even though hepatitis B has become less of a problem, non-A, non-B hepatitis has been recognized as a significant problem since 1979. With the availability of serological testing for hepatitis C virus (HCV), more specific information is now available in regard to HCV infection in dialysis patients. The prevalence of anti-HCV in haemodialysis (HD) patients is quite variable, ranging from 5 to over 50%. Anti-HCV positivity is associated with previous blood transfusions, mode of therapy and duration of haemodialysis. In Spain and Italy, the annual seroconversion rates of HCV antibodies in dialysis patients are 2-9%; this rate was much higher in Taiwan (15%). Whether patients with HCV infection should be identified and isolated during HD treatment is an issue of controversy. Transplantation is associated with increases in hepatitis B virus (HBV) replicative markers. The survival disadvantage in HBsAg-positive recipients usually did not become apparent until 8 years after transplantation. Hepatitis C virus-infected renal transplant recipients are presumably in a similar situation to patients with hepatitis B, although confirmatory data are currently lacking. Coinfection of HBV and HCV may lead to aggressive liver disease and cirrhosis. A hepatitis B vaccine is recommended for all susceptible dialysis patients. Dialysis patients have lower response rates to hepatitis B vaccines than do other people. Currently, no vaccine is available for hepatitis C. To date, there are no effective treatments available for hepatitis B and hepatitis C. Combination therapy with interferon/lamivudine for hepatitis B and interferon/ribavirin for hepatitis C may offer a promise of effective control of viral replication in the future.

Hepatitis C virus infection among institutionalised psychiatric patients: a regression analysis of indicators of risk

BACKGROUND/AIMS

Institutionalised psychiatric patients are at increased risk of developing chronic infection with hepatitis B virus (HBV). However, little information is available on transmission and epidemiology of hepatitis C virus (HCV) in this setting. The aim of this study was to identify potential risk factors of acquiring HCV infection in two large psychiatric institutions in northern Italy.

METHODS

We designed a case-control study using randomly selected controls from the same study database, consisting of a total of 1180 patients, in order to satisfy the principle that both cases and controls should be representative of the same base experience. A multiple regression logistic analysis was used to identify features that could predict exposure to HCV as evidenced by the presence of circulating anti-HCV antibodies.

RESULTS

Anti-HCV was detected in 79 patients (6.7%). The prevalence of viraemia and the distribution of genotypes were very similar to those found in subjects with chronic HCV infection drawn from the same geographical area. Multivariate analysis indicated that a diagnosis of psychosis and a history of trauma were statistically significant independent risk factors associated with a positive anti-HCV result (OR 2.615, 1.273-5.373 95% CI and OR 2.096, 1.133-3.877 95% CI, respectively).

CONCLUSIONS

The findings of this large epidemiological study show for the first time that prolonged residence in psychiatric institutions does not entail per se a significant risk of acquiring HCV infection. Since transmission of HCV in this setting appears to occur predominantly via classical parenteral routes, simple prophylactic measures appear to be adequate to prevent infection.

Laparoscopic evaluation of liver disease in chronic renal failure prior to renal transplantation

BACKGROUND

Diagnostic laparoscopy with liver biopsy has been shown to be safe and effective in the evaluation of patients with chronic liver disease. Patients with end-stage renal disease may be more prone to bleeding complications secondary to liver biopsy as a result of multiple factors directly related to their underlying renal condition.

METHODS AND PATIENTS

From January 1994 to June 1996, 16 patients with end-stage renal disease and hepatic dysfunction (6 women and 10 men) underwent diagnostic laparoscopy with liver biopsy prior to renal transplantation at the University of Miami School of Medicine. Laparoscopy was performed using a 5 mm video laparoscope with a left paramedian approach. The mean patient age was 46 years. Fourteen patients had chronic hepatitis C with a reactive anti-HCV by ELISA; one patient had chronic hepatitis B with reactive HBsAg, and one patient was co-infected with both hepatitis B and C viruses.

RESULTS

Two patients developed hypotension related to the procedure and one patient developed an intra-abdominal hemorrhage 5 days after laparoscopy that did not require surgical intervention. Biopsy findings were as follows: 13 patients had mild chronic hepatitis; 2 patients had chronic hepatitis with bridging fibrosis; and 1 patient was cirrhotic. Prior kidney transplantation or peritoneal dialysis did not preclude the performance of laparoscopy.

CONCLUSION

Diagnostic laparoscopy can be safety performed in patients with end-stage renal disease with acceptable morbidity and mortality.

Histopathological impacts of hepatitis virus infection in hemodialysis patients: should liver biopsy be performed before renal transplantation?

To evaluate the histologic changes in the livers of renal transplant candidates who were infected with hepatitis viruses, we performed a percutaneous liver biopsy in each of 74 regular hemodialysis patients. Forty percent of them were seropositive for the antibody to hepatitis C virus (anti-HCV) whereas 29.7% had anti-HCV and antibody to hepatitis B surface antigen (anti-HBs) concomitantly. Seven (9.5%) were seropositive for only hepatitis B surface antigen HBsAg. Histopathological examination revealed that 30% of patients had chronic active hepatitis (CAH), 11% had chronic persistent hepatitis (CPH), and 3% displayed histopathological evidence of cirrhosis. Eleven of 22 patients with CAH were positive for only anti-HCV, and 2 of 22 were positive for only HBsAg. One patient had HBsAg and anti-HCV together, and 8 of 22 had anti-HBs and anti-HCV concomitantly. None of the anti-HBs positive patients exhibited abnormal histopathological changes. We found no statistically significant difference in histopathological findings between the HBsAg positive and anti-HCV positive patients. As 32 of 74 patients (43%) had some degree of chronic liver disease, we concluded that it is prudent to evaluate liver histology in HBsAg and anti-HCV seropositive renal transplant candidates before transplantation.

Hepatitis C in dialysis patients

Patients on hemodialysis have a higher prevalence of hepatitis C (HCV) infection compared with the general population. Several factors have been associated with an increased risk of HCV infection in hemodialysis patients, including number of blood transfusions, duration of hemodialysis, previous transplantation, intravenous drug abuse, male gender, and in-center hemodialysis. In addition, there is mounting evidence to suggest nosocomial transmission within hemodialysis units. Although the precise modes of transmission have not been identified, breakdown in standard infection control practices, physical proximity to an infected patient, and sharing of dialysis machines are possible causes. Nonetheless, at the present time, the Centers for disease Control and Prevention (CDC) does not recommend dedicated machines, patient isolation, or a ban on re-use in hemodialysis patients with HCV infection. Consequently, strict adherence to universal precautions and careful attention to hygiene are recommended to reduce the transmission of HCV in dialysis units.

Nosocomial transmission of hepatitis C virus in haemodialysis patients

A systematic virological follow-up of 114 haemodialysis patients treated in the same unit showed that 37, including 17 PCR positive patients, were seropositive for hepatitis C virus (HCV). Type 1b HCV was detected in 10 patients and was much more frequent in this population than in the whole population of patients treated in the hepatogastroenterology departments in southeastern France. The E1/E2 genomic region of seven type 1b HCV strains was sequenced. In four patients, a similar strain was detected in both the E1 variable region and the E2 hypervariable region (HVR1). In addition, two of these four patients were seronegative and PCR negative at the beginning of the study and had not been transfused or transplanted during this period. A phylogenetic tree was drawn which confirmed that these strains were very similar and showed that HCV was transmitted via the nosocomial pathway in this haemodialysis unit.

Hepatitis C biochemical remission and viral replication in haemodialysis patients

The natural course of non-A, non-B (type C) hepatitis was studied in 62 haemodialysis patients. From the onset of the disease, serum alanine aminotransferase levels were monitored monthly for 9-218 mon (median 115). After fluctuation of aminotransferase levels for 1-206 mon (median 39), 57 (92%) patients showed normalization of these levels lasting until the end of the follow-up, which was for > 2 yr in 31 (50%) cases and for > 5 yr in 15 (24%) cases. At the end of follow-up, hepatitis C viraemia was assessed by reverse transcription-polymerase chain reaction (RT-PCR) and branched DNA (bDNA) assay. Viraemic levels were significantly lower in the 15 patients with normal aminotransferase for > 5 yr (median RT-PCR + ve/bDNA-ve, range RT-PCR-ve to 10(6.7) Eq/mL) than in the 47 cases with normal levels for < 5 yr (median 10(6.6), range RT-PCR + ve/bDNA-ve to 10(7.6) Eq/mL) (P < 0.01). Moreover, a significant inverse relation was observed between viraemic levels and the duration of aminotransferase normalization (r = -0.46, P < 0.01). These findings indicate that biochemical remission of hepatitis C may be frequent in haemodialysis patients and may be related to viral attenuation.

Phylogenetic analysis of hepatitis C virus isolates from hemodialysis patients

A high prevalence of hepatitis C virus (HCV) infection has been reported in hemodialysis patients. Main risk factors for transmission are previous blood transfusions and possibly nosocomial infections within the dialytic environment. In the present study 224 hemodialysis patients from the same department were tested for the presence of anti-HCV antibodies and HCV-RNA. The presence of anti-HCV in hemodialysis patients was correlated with a history of more than 10 blood transfusions (P = 0.001) and with a duration of hemodialysis treatment for more than 10 years (P = 0.001). The issue of possible patient-to-patient infection was addressed by sequence analysis of all HCV-RNA positive hemodialysis patients (N = 14) together with a control panel of HCV isolates from 56 unrelated non-hemodialysis patients with hepatitis C from the same geographical area. Subsequent phylogenetic analysis of nucleotide sequences obtained from the 5'-noncoding region and the nonstructural NS-5 region of the HCV genome revealed that only two hemodialysis patients were infected by a highly related HCV isolate. The remaining HCV-RNA positive hemodialysis patients including those without previous blood transfusions were all infected by phylogenetically-distant HCV isolates, providing evidence against a nosocomial transmission route. The data of the present study show that molecular epidemiological techniques are important to investigate the issue of nosocomial infection. In our hemodialysis unit patient-to-patient infection appears uncommon and draws attention towards other possible (such as, blood products such as human serum albumin, immunoglobulins) or even yet unrecognized transmission routes.