Destruction of hepatitis C virus particles by haemodialysis

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.

Histological features of chronic hepatitis C in haemodialysis patients

BACKGROUND & AIMS

HCV infection in haemodialysis (HD) patients is still a matter of investigation. The aim of this study was to determine the histology of chronic hepatitis C (CHC) in HCV-infected HD patients within the context of a comparative analysis including non-uraemic patients with CHC. The relative importance of virological, demographic and clinical parameters on disease manifestation was examined.

METHODS

Sixty-one consecutive liver biopsies from HD patients and 326 from non-uraemic patients with chronic HCV infection were comparatively evaluated.

RESULTS

Haemodialysis patients with CHC were older than control subjects (P = 0.031), showing a similar HCV genotype distribution (P = 0.328) and lower viral load (P = 0.001). CHC in HD patients was significantly milder according to stage (P = 0.033), grade and its parameters (periportal activity, portal inflammation and lobular activity) (P < 0.001). The frequency of lymphoid aggregates (10.2% vs. 50%, P < 0.001), bile duct lesions (1.7% vs. 22.1%, P < 0.001) and extent of steatosis (P = 0.022) in HD group was significantly reduced. Multivariate analysis showed that non-uraemic patients had 2.3 times higher risk of developing steatosis independently of genotype distribution and age. In HD group, genotype 3, longer HD duration and age at infection were significantly associated with steatosis, while older age at infection correlated with advanced fibrosis.

CONCLUSIONS

Chronic hepatitis C in HD patients is usually very mild, losing its diagnostic histological features while patient's age and age at infection retain their prognostic significance. The weak inflammatory response, probably because of immunocompromised status and low viral load, may present a beneficial factor in the natural course of the disease.

Hepatitis C infection and chronic renal diseases

Hepatitis C virus (HCV) infection and chronic renal diseases can be linked in two different ways. Some forms of renal disease are precipitated by HCV infection, while patients with end-stage renal disease are at increased risk for acquiring HCV infection. Patients with chronic HCV infection and renal disease have a poor prognosis. Most studies on treatment of HCV and renal diseases have been uncontrolled trials with small number of subjects. So, there is a lack of evidence-based recommendations and guidelines on the management of this condition. In this review, we will attempt to provide the most recent insights on HCV infection both as a extrahepatic manifestations and as a complication of end-stage renal patients.

Transcription-mediated amplification (TMA) for the assessment of viremia in hemodialysis patients with hepatitis C

The diagnosis of hepatitis C virus (HCV) infection in hemodialysis patients is difficult particularly due to the presence of intermittent viremia. The aims of this study were: (a) to determine the prevalence of intermittent viremia in hemodialysis patients with anti-HCV antibodies who tested negative for HCV RNA by PCR at the first evaluation and (b) to evaluate the contribution of the transcription-mediated amplification method (TMA) to the diagnosis of viremia in the PCR-negative samples. One hundred and six patients with anti-HCV antibodies and an initial negative result for HCV RNA by PCR were included. An additional sample was collected for a second HCV RNA test by PCR after a minimum interval of 3 months and a positive result characterized intermittent viremia. HCV RNA was investigated by TMA in the PCR-negative sample of patients with intermittent viremia, and in the most recent sample from patients with PCR-negative results in both determinations. Intermittent viremia was observed in 60/106 (57%) patients (57% men; age: 45 ± 10 years). Fifty-one of the 60 negative samples from patients with intermittent viremia and 29/46 double-negative patients were tested by TMA. This assay detected viremia in 20/51 (39%) samples of intermittent viremia and in 2/29 (7%) of double-negative samples. The results showed that intermittent viremia is frequent in hemodialysis patients who tested negative for HCV RNA by PCR. Therefore, a second HCV RNA test is necessary for all HCV RNA-negative patients. The TMA assay appears to be the best first screening test for viremia in this population.

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.

Hepatitis C virus and kidney: a strong association with different clinical aspects

The most frequent kidney disease associated with chronic hepatitis C virus (HCV) infection is membranoproliferative glomerulonephritis in patients with type II mixed cryoglobulinaemia. The principal clinical manifestations of glomerular disease in HCV-infected patients are the presence of proteinuria and haematuria with or without impaired kidney function. Pharmaceutical regimens vary because the main pathogenesis of renal dysfunction often mediated by cryoglobulins has not been fully elucidated. HCV infection remains common in patients on renal replacement therapy and has an adverse impact on their survival. Safe and effective pharmaceutical regimens have not been yet established and nosocomial spread within dialysis units continues to occur. Monotherapy with interferon for HCV infection is probably more effective in dialysis than in non-uraemic patients, while experience with ribavirin is limited because of its adverse haemolytic effect. Based on shortage of cadaver kidneys and the fact that HCV renal transplant recipients have better survival than stay on maintenance haemodialysis or at list for transplantation, health organization proposed the use of cadaver kidneys from anti-HCV-positive donors, bringing up concerns and conflicting views. This present review describes the main renal manifestations of HCV infection, the epidemiological and clinical characteristics of chronic kidney disease population and comments on the limitations and shortcomings of current therapeutical regiments.

Effect of hemodialysis schedules and membranes on hepatocyte growth factor and hepatitis C virus RNA levels

Hemodialysis induces production of the hepatocyte growth factor (HGF) and decrease of serum hepatitis C virus (HCV) RNA in patients with HCV infection, but it is not known if the hemodialysis schedule or type of membrane affect both the HGF production and HCV viremia. The effects on both parameters of alternate-day intermittent hemodialysis and short-daily hemodialysis and high and low flux membranes were investigated in 41 patients treated by hemodialysis. Sixteen (39%) patients were anti-HCV positive and 11 (69%) had HCV RNA. Twenty-six patients were on alternate-day intermittent and 15 on short-daily hemodialysis. High flux membranes were used for 29 patients and low flux membranes for 12 patients. A decrease in HCV RNA was observed at the end of hemodialysis (8.6 x 10(5) +/- 1.1 x 10(6) IU/ml vs. 4.4 x 10(5) +/- 7.3 x 10(5) IU/ml, P = 0.003). The proportion of HCV RNA decrease was similar in patients dialyzed with both schedules and with both types of membranes. The HGF levels increased from 2,605.9 +/- 1,428.7 to >8,000 pg/ml at 15 min. At the end of the session, the HGF levels decreased to 5,106.7 +/- 2,533.9 pg/ml. The HGF levels at the start of the next session were similar to those at baseline (2,680.0 +/- 1,209.3 pg/ml). The increase and dynamics of the HGF levels were similar in patient's hemodialyzed with both schedules and with both types of membranes. These results suggest that changes in HCV RNA and HGF levels during hemodialysis are not influenced by the schedule or type of membrane used.

Impact of hemodialysis therapy on hepatitis C virus infection: a deeper insight

Hepatitis C Virus (HCV) infection remains prevalent in patients receiving regular dialysis all over the world. The adverse impact of anti-HCV serologic status on mortality in the dialysis population has been documented. Antiviral therapy for hepatitis C in chronic kidney disease (CKD) patients, including the dialysis population, is still unsatisfactory. Several findings support a different course of HCV in dialysis patients versus the non-uremic population. The HCV viral load appears lower in hemodialysis patients with HCV despite the immune compromise caused by chronic uremia; the histologic abnormalities seem milder, and a severe clinical course of chronic hepatitis C is unusual in most hemodialysis (HD) patients. It appears that the HD procedure per se can preserve patients from an aggressive course of HCV by reducing the viral load (HCV RNA). The mechanisms by which the HD procedure lowers HCV viremia remain largely speculative: the passage of viral particles into the dialysate, the trapping of the virus on the surface of the dialyzer membrane, and an indirect host-mediated mechanism have been cited. The latter hypothesis implicates the production of interferon-alpha, hepatocyte growth factor, or other cytokines provided with antiviral activities during the hemodialysis sessions. Clinical trials aimed at clarifying this issue are under way.

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).

Kinetics of hepatitis C viral RNA and HCV-antigen during dialysis sessions: evidence for differential viral load reduction on dialysis

Hepatitis C infection is a common problem in dialysis units. The prevalence ranges from 3% to more than 50%. Several reports have described a variable reduction of HCV-RNA during hemodialysis treatment sessions. But so far nothing is known about the HCV antigenemia or the kinetics of the reduction of HCV-RNA and HCV antigenemia during these sessions. HCV-RNA was monitored using the VERSANT HCV bDNA assay 3.0 (Bayer Healthcare Diagnostics, Leverkusen, Germany) or the HCV-Monitor TaqMan (Roche Diagnostics). HCV antigenemia was tested by using Ortho-trac-C assay (Ortho Clinical Diagnostics, Neckargemünd, Germany). Kinetics of HCV-RNA were available in 15 dialysis sessions measured by bDNA assay and in 5 dialysis sessions measured by rt-PCR. Quantitative HCV-antigenemia was available in fourteen dialysis sessions. Not only HCV-RNA but as expected also the HCV-antigenemia fell during the dialysis session. However, while the average reduction of HCV-antigen appears steady and linear, the level of HCV-RNA seems to be stable during the first 3 hr of dialysis, and decreases rapidly during the last 2 hr. The results seem to be independent of the HCV-RNA detection method. The different kinetics of HCV RNA and HCV antigen load suggest that there are different mechanisms responsible for the reduction of the HCV antigen and HCV-RNA, respectively. Reduction of viral load during dialysis session indicates a potential benefit of dialysis in case of HCV associated antiviral therapy.

The treatment of chronic hepatitis C with peginterferon alfa-2a (40 kDa) plus ribavirin in haemodialysed patients awaiting renal transplant

BACKGROUND/AIMS

We undertook a pilot study to investigate the efficacy and safety of peginterferon alfa-2a (40 kDa) plus ribavirin in haemodialysed chronic HCV patients awaiting renal transplant.

METHODS

Patients received peginterferon alfa-2a 135 microg/week plus ribavirin 200 mg/day for 24 or 48 weeks (genotype non-1 and 1, respectively). The dose of ribavirin was tailored according to plasma concentrations and to haemoglobin levels. Outcomes in treated patients were compared with those of a matched untreated control group.

RESULTS

Thirty-five patients received treatment, while 35 served as untreated controls. Thirty patients completed treatment; patients were withdrawn due to transplantation (n=2), severe anaemia (n=1), dermatitis (n=1) and non-response (n=1) resulting in a drop-out rate of 14%. Overall, 34/35 treated patients were HCV RNA negative at week 4 and had undetectable RNA at the end of treatment, compared with none of the untreated controls (ETR 97% vs 0%; p<0.001). Moreover, all achieved sustained virological response after 24 weeks of treatment-free follow-up versus no control patients (SVR 97% vs 0 %; p<0.001).

CONCLUSIONS

In this study, we have shown for the first time in a large cohort of patients that HCV-patients on haemodialysis can be treated successfully with peginterferon alfa-2a (40 kDa) plus ribavirin.

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.

Natural history of chronic hepatitis C in patients on hemodialysis: Case control study with 4-23 years of follow-up

AIM: Hepatitis C virus (HCV) infection is very common among end-stage kidney disease patients on hemodialysis, but its natural history is not known.

METHODS: In this study, 189 dialysis patients (case) positive for HCV antibodies who were followed up for more than 4 years were compared with twice as many sex/age matched controls with chronic hepatitis C who were diagnosed in the same month as the case and followed up for comparable periods. The longest follow-up was 23 years in dialysis cases. The disease activities were graded into “asymptomatic” if ALT was less than 40 (35 in cases) IU/L, “low activities” if ALT was 40 (35)-79 IU/L, and “high activities” if ALT was above 80 IU/L during the last or latest 4 year period.

RESULTS: All 25 dialysis cases who were followed up for more than 15 years were asymptomatic and 15 of them were negative for HCV RNA. Of the 50 controls followed up for more than 15 years, 34 had high activities, and none cleared HCV RNA. There were 60 controls who were asymptomatic, but they were all positive for HCV RNA, while 22.3% of asymptomatic dialysis cases were RNA negative. No dialysis patients with chronic hepatitis C progressed to cirrhosis, whereas the disease progressed to cirrhosis in more than one quarter of the controls. These differences were highly significant (P < 0.0001).

CONCLUSION: Chronic hepatitic C among hemodialysis patients is mild in disease activity, and is not progressive, perhaps due to immunological abnormalities in these patients. Hepatic C virus is frequently cleared in asymptomatic dialysis patients during a long course. A possible mechanism for viral clearance is viral particle destruction on the surface of the dialyzer membrane.

Hepatitis C virus decreases in patients with maintenance hemofiltration therapy

Low incidence rates of hepatocellular carcinoma and cirrhosis in HCV-antibody-positive patients on chronic hemodialysis are reported. Among the patients, two cases undergoing negative conversion of the anti-HCV-antibody were found. Considering the size of the virus particles and the pore size of the dialysis membrane, it seems the virus does not escape from the membrane pore. Indeed, virus particles may be trapped and destroyed at the membrane surface. The size of HCV-RNA titers in HCV-antibody-positive patients receiving various kinds of chronic blood purification procedures are of interest. The subjects included 15 hemodialysis patients, 10 hemofiltration patients, 9 continuous ambulatory peritoneal dialysis patients, 7 chronic renal failure predialysis patients, and 14 patients with excellent renal function. The concentration of HCV-RNA particles in patients receiving chronic hemofiltration was significantly lower than that in patients of other groups. Hemofiltration, which is routinely performed at over 150 mm Hg TMP, may be an important key to decreasing HCV-RNA particles by a mechanism such as destruction.

Granulocyte and Monocyte Adsorptive Apheresis for Patients with Chronic Hepatitis C Virus Infection: A Report on Six Cases with High Plasma Viremia

Granulocytes and monocytes/macrophages (GM) are known to constitute extra-hepatic sites for hepatitis C virus (HCV) replication and dissemination. Accordingly, we thought that selective GM adsorptive apheresis (GMA) might contribute to the treatment of HCV in patients with high viremia (HCV-RNA > 100 kIU/mL). Of six patients (three males and three females), mean age 62.2 years, five had not responded to interferon-alpha (INF-alpha) and one was INF-alpha naïve. Each patient received five GMA sessions, once a week for 5 weeks. The two antecubital veins were used as blood access and return lines and the apheresis was performed at 30 mL/min for 60 min. Treatment efficacy was assessed by monitoring changes in plasma HCV-RNA and aminotransferase. Granulocyte and monocyte/macrophage adsorptive apheresis was well tolerated. During each GMA, there was on average a 52.9% fall in plasma HCV-RNA, but HCV-RNA increased again during the time before the next GMA. There was no marked change in either aminotransferase during GMA. Furthermore, beyond the last GMA, HCV-RNA increased together with worsening aminotransferase in three of six patients. In conclusion, it would appear that GMA can partially reduce plasma HCV and GMA at a frequency of one session/week for 5 consecutive weeks but that this was inadequate to induce a sustained decrease in plasma HCV-RNA in patients with high viremia without simultaneous administration of antiviral medications. The most effective frequency of GMA needs to be determined in future clinical studies.

Changes in viremia and circulating interferon-alpha during hemodialysis in hepatitis C virus-positive patients: only coincidental phenomena?

BACKGROUND

It has been hypothesized that hemodialysis (HD) treatment per se can preserve patients from an aggressive course of hepatitis C virus (HCV) infection by reduction of viral load. The aim of the present study in HCV-positive (HCV+) HD patients is to determine whether HD induces the production of interferon-alpha (IFN-alpha) and if such production can contribute to viremia reduction.

METHODS

To address this issue, HCV RNA and IFN-alpha levels were determined in 11 HCV+ patients immediately before and at the end of a 4-hour dialysis session using cellulosic membranes and 24 and 48 hours later, ie, immediately before the subsequent dialysis session using the same membrane and at the end of the dialysis session. The same protocol was repeated 1 week later using a high-biocompatibility synthetic membrane.

RESULTS

HCV titer decreased in all patients after dialysis (range, 3% to 95%; P = 0.001) and thereafter progressively increased and returned to basal levels within 48 hours, with a new reduction during the next dialysis treatment. There was no significant difference in the magnitude of changes in HCV titers in tests performed using cellulosic or synthetic membranes. Plasma IFN-alpha levels increased markedly after dialysis using both cellulosic (in 9 of 11 cases) and synthetic membranes (in 10 of 11 cases; P < 0.01) and returned to basal levels within 48 hours; thereafter, IFN-alpha levels increased again during the next dialysis session. In some patients, plasma IFN-alpha levels after HD were approximately 50% of the level observed after therapeutic administration of 6 million units of IFN-alpha to 4 HD patients with chronic hepatitis.

CONCLUSION

Although without a proven direct cause-effect relationship between HCV level reduction and induction of IFN-alpha after dialysis, our observation suggests an additional new mechanism for the unusually mild course of HCV infection in HD patients.

Viraemia, cryoglobulins and autoantibodies in haemodialysis patients infected with hepatitis C virus

OBJECTIVES

The clinical features of hepatitis C virus (HCV) infection depend on the immune and autoimmune reactions induced by the virus. Chronic renal failure might alter the pattern of these reactions. The aim of this study was to determine the prevalence of cryoglobulinaemia, the frequency of autoantibodies and HCV viral load in HCV infected Greek patients on chronic haemodialysis.

METHODS

Seventy-three HCV Ab(+) patients on maintenance haemodialysis and 87 otherwise normal patients with chronic HCV infection were evaluated for the presence of cryoglobulins, autoantibodies and viral markers.

RESULTS

Cryoglobulins were detected in 22/73 (30.1%) haemodialysis patients and in 23/87 (26.4%) patients with normal renal function (NS). The mean cryocrit value was significantly lower in the haemodialysis group ( = 0.002). Haemodialysis patients had significantly higher levels of C4 component of complement and lower incidence of rheumatoid factor than those of patients with normal renal function. Serum HCV RNA levels were found significantly lower in the haemodialysis group (median, 2.20 Meq/ml; range, 119.9 Meq/ml) than in the group with normal renal function (median, 4.50 Meq/ml; range, 114.9 Meq/ml; = 0.046). The distribution of genotypes was not different between the two groups.

CONCLUSIONS

There are subtle differences in autoimmune features of HCV infection if the patients are also haemodialysed for renal failure. HCV viral load is lower in haemodialysis patients, with no difference in the HCV genotype prevalence. The clinical significance of these findings is unknown.

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.

Hepatitis C virus in blood and dialysate in hemodialysis

The prevalence of hepatitis C virus (HCV) positivity among hemodialysis patients remains high compared with that of the healthy population, and thus the issue of safety and environmental protection must be addressed. The purpose of this study is to evaluate the dynamics of prehemodialysis and posthemodialysis blood HCV levels and HCV escape to spent dialysate. Because heparin has an inhibitory effect on the reverse-transcription polymerase chain reaction (RT-PCR) assay, a serine protease inhibitor (nafamostat mesilate) was used as the anticoagulant for hemodialysis. High-flux polysulfone membrane dialyzers were used; dialyzer reuse was not performed. Multicyclic RT-PCR was performed for the quantitative detection of HCV. To elucidate HCV escape to spent dialysate, a portion of total spent dialysate was continuously extracted in a sterile fashion using a minutely adjusted syringe pump. No HCV extravasation to spent dialysate was found, although HCV copy numbers were reduced to a statistically significant level in postdialysis blood compared with predialysis levels (P: < 0.05; n = 20). The need to establish standards for risk management in dialysis centers is evident. The data obtained in this study strongly suggest that to minimize the risk for HCV transmission, lower transmembrane pressure (TMP) should be used in the hemodialysis of HCV-positive patients, with fresh polysulfone dialyzers and dialysis settings of 180 to 250 mL/min for blood flow, 500 mL/min for dialysate flow, and less than 18.72 mm Hg for TMP.

Low levels of hepatitis C virus RNA in blood of infected patients under maintenance haemodialysis with high-biocompatibility, high-permeability filters

BACKGROUND

Patients undergoing maintenance haemodialysis are often infected with hepatitis C virus, yet the clinical course of liver disease is usually mild. We investigated whether the hepatitis C virus viral load is influenced by the haemodialytic procedure and the type of dialyser.

METHODS

Hepatitis C virus-RNA levels were measured using a quantitative polymerase chain reaction assay in predialysis blood from 51 hepatitis C virus-infected patients dialysed with different membranes. Paired pre- and post-dialysis measurements were also obtained in 18 patients.

RESULTS

Patients dialysed using cuprammonium-regenerated cellulose membranes with low (cuprofan) or intermediate (cellulose acetate or diacetate) biocompatibility had higher pre-dialysis hepatitis C virus-RNA levels (p<0.05] compared to those dialysed with synthetic high-biocompatibility, high-permeability polymeric membranes (polyacrylonitrile, polysulfone, polymethylmethacrylate or polycarbonate). Hepatitis C virus-RNA levels were unrelated to the duration of haemodialysis and the presence of abnormal transaminases. A significant reduction (p=0. 04) of serum hepatitis C virus-RNA levels was observed after a single haemodialysis, particularly in patients with high pre-dialysis viral load. Patients with low pre-dialysis hepatitis C virus-RNA levels (<2. 5 x 10(3) copies/ml) exhibited only minimal changes following the procedure. Four patients with medium-high basal viral load switched from a low-biocompatibility/low-permeability to a high-biocompatibility/high permeability filter had a marked reduction of viraemia after three weeks, in one case followed by a new increase after return to the original filter.

CONCLUSIONS

Haemodialysis with high-biocompatibility/high-permeability filters in hepatitis C virus-infected patients is associated with low blood levels of hepatitis C virus-RNA. This finding may be of clinical relevance, especially in patients listed for kidney transplantation.

Maintenance hemodialysis decreases serum hepatitis C virus (HCV) RNA levels in hemodialysis patients with chronic HCV infection

OBJECTIVE

Hepatitis C virus (HCV) infection is a major complication among hemodialysis patients the world over. To determine the natural course of HCV viremic levels in patients on maintenance hemodialysis, we prospectively quantified the HCV RNA levels in serial blood samples from hemodialysis patients and compared them with those in nonuremic subjects.

METHODS

The population studied included 98 hemodialysis patients and 228 nonuremic subjects with chronic HCV infection. HCV RNA was detected by polymerase chain reaction (PCR) and the levels were determined by branched DNA probe assay. HCV RNA genotypes were determined by PCR using type-specific primers.

RESULTS

HCV RNA levels were significantly lower in hemodialysis patients (median, 0.4x10(6) genome equivalent [Meq]/ml) than in nonuremic subjects (median, 3.0 Meq/ml) (p<0.05). HCV of genotype 1b was prevalent in the hemodialysis patients (81.6%) and nonuremic subjects (88.6%). HCV RNA levels in 20 hemodialysis patients with genotype 1b were significantly reduced after each hemodialysis procedure (p<0.05). The 3-yr prospective observation from 1995 to 1998 showed a significant decrease of HCV RNA levels in 47 hemodialysis patients with genotype 1b (median, 1.9-0.9 Meq/ml, p<0.05), whereas levels in 155 nonuremic subjects with genotype 1b did not decrease (median, 2.6-3.0 Meq/ml). There were no patients or nonuremic subjects with undetectable HCV RNA by a PCR assay during the observation period.

CONCLUSIONS

These observations suggest that maintenance hemodialysis decreases the HCV RNA levels in hemodialysis patients with chronic HCV infection, but does not produce clearance of the viremia.

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.

Hemodialysis prevents liver disease caused by hepatitis C virus: role of hepatocyte growth factor

Hemodialysis prevents liver disease caused by hepatitis C virus: Role of hepatocyte growth factor.

BACKGROUND

Hemodialysis increases markedly the serum levels of hepatocyte growth factor (HGF) so that regular dialysis treatment (RDT) mimics the regular administration of HGF as a drug. Therefore, we have studied the effects of dialysis-associated HGF production on the severity of liver damage caused by hepatitis C virus (HCV).

METHODS

Biochemical tests of liver function and liver biopsy were performed in 10 patients on RDT and in 11 patients without renal disease (WRD) converted to anti-HCV serum-positive test for the same time (48 +/- 4 months). The HGF serum concentration was measured by enzyme immunoassay. In patients on RDT, HGF was measured just before starting a dialysis session (T0), at 15 and 240 minutes of dialysis (T15 and T240), and 24 hours later (T24 hr).

RESULTS

Serum HGF was similar in WRD (average 0.17 ng/ml) as in RDT at T0 (0.25 ng/ml). In RDT serum HGF increased markedly at T15 and T240 (5.51 and 2.67 ng/ml, respectively, P < 0. 001 vs. WRD and T0) and was still higher than baseline at T24 hr (0. 41 ng/ml, P < 0.05). Both grade of necroinflammatory activity and stage of fibrosis were significantly lower in RDT than in WRD (both, P < 0.001). The number of apoptotic hepatocytes was also significantly reduced in patients on RDT compared with patients WRD.

CONCLUSION

These results show that HCV-related liver disease is more benign in patients on RDT. The phenomenon may depend on the marked and prolonged HGF release caused by dialysis.

GBV-C/HGV-RNA in serum and peripheral blood mononuclear cells in hemodialysis patients

BACKGROUND

Hemodialysis patients are at high risk of hepatitis B, C, and G virus infection. The prevalence of GBV-C/HGV-RNA was analyzed in serum and peripheral blood mononuclear cells (PBMCs) from 52 hemodialysis patients.

METHODS

GBV-C/HGV-RNA detection was performed by reverse transcription-polymerase chain reaction (RT-PCR) with primers of 5'-noncoding (5'-NC) and NS3 regions of the GBV-C/HGV genome. To increase sensitivity, serum samples were ultracentrifuged prior to the RT-PCR to concentrate the viral particles. The amplified products from 20 serum and 5 peripheral blood mononuclear cells (PBMC) samples were sequenced.

RESULTS

GBV-C/HGV-RNA was detected in sera of 9 (17%) and in PBMCs of 30 (58%) patients. After serum ultracentrifugation, GBV-C/HGV-RNA was positive in 20 (95%) of the patients, with GBV-C/HGV-RNA only in PBMCs. Thus, GBV-C/HGV-RNA was detected in serum and PBMCs from 29 (56%) patients, four of whom had antibodies against GBV-C/HGV E2 protein (anti-HGE2); one patient (2%) had GBV-C/HGV-RNA only in PBMCs, but was anti-HGE2 positive. Seven (32%) patients who did not have GBV-C/HGV-RNA were anti-HGE2 positive. The nucleotide sequence homology between serum samples from the patients who were GBV-C/HGV-RNA positive after ultracentrifugation, and paired serum and PBMCs from five of them, ranged from 90 to 96% and from 92 to 98%, respectively.

CONCLUSIONS

We found a high prevalence of GBV-C/HGV-RNA in serum and PBMC samples from hemodialysis patients. Whether or not this finding can be extended to other populations requires further study.

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.

Acute hepatitis C among renal failure patients on chronic haemodialysis

Hepatitis C virus (HCV) infection is common in haemodialysis units, yet little information is available about the clinical feature of acute hepatitis C among renal failure patients. The present study is based on 49 cases of acute hepatitis C seen at a haemodialysis centre where sporadic nosocomial infection was occurring up to June 1993. Liver function tests were done at 4 weekly intervals on all dialysis patients, anti-HCV antibodies were tested by the C-100 and second generation tests and serum HCV-RNA was determined by the branched DNA and Amplicore tests. Diagnosis of acute hepatitis C was made on the basis of an acute rise in alanine aminotransferase (ALT) and seroconversion to positive anti-HCV antibodies. Clinical presentation of acute hepatitis was generally mild with rare overt jaundice and the diagnosis was possible only from increased ALT, which was generally low. Spontaneous resolution of acute hepatitis within 8 months with clearance of viral RNA occurred in only four cases, 91.8% of patients developing chronic hepatitis. Biopsy in 12 cases with high ALT levels showed mild to moderate inflammatory activities. In conclusion, the clinical presentation of acute hepatitis C is generally mild in chronic haemodialysis patients, but spontaneous resolution is infrequent. A longer follow-up period is required for defining the long-term prognosis.

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.

Determination of genotypes of hepatitis C virus in Venezuela by restriction fragment length polymorphism

Hepatitis C virus genotypes in Venezuela were analyzed by restriction fragment length polymorphism in the 5' noncoding region. The absence of BstUI digestion was found to be a useful marker for genotype 2 specimens. From 122 serum samples, 66, 20, and 2.5% were classified as genotypes 1, 2, and 3, respectively; 0.8% were classified as genotype 4; and 10% appeared to be mixed infections.