Hepatitis C virus in chronic hemodialysis patients with non-A, non-B hepatitis

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

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

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.

High prevalence of a rare hepatitis C virus in patients treated in the same hemodialysis unit: evidence for nosocomial transmission of HCV

Hepatitis C virus (HCV) is a major cause of hepatitis among patients treated with maintenance hemodialysis. Blood transfusion appears to be the primary risk factor, but nosocomial transmission of HCV in the dialytic environment has been hypothesized. We addressed this issue by analyzing the individual variation of genomic sequences of HCV in 28 patients on chronic hemodialysis (HD) from the same department and 25 environmentally unrelated patients with HCV-related liver disease. Genome variations of HCV were studied by single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products obtained from the 5'-untranslated region of the viral genome and by sequence analysis. Six different SSCP patterns were identified in HD patients versus 16 in control patients. Among HD patients the three more frequent SSCP patterns accounted for 85% of observations, while in the control group each pattern was found in 4 to 12% of patients. The ability of SSCP to discriminate sequence variation was proven by sequence analysis which confirmed identity/diversity of sequences selected by SSCP. Moreover, sequence analysis permitted a recognition of the most frequent genome observed in HD patients as a type 4 HCV, which is considered to be rare in the Italian population. The relative homogeneity of HCV variants in HD patients treated in the same HD and the high prevalence in this unit of a rare viral variant support the possibility of a nosocomial transmission of HCV in the dialytic environment.

Environmental transmission of hepatitis B and hepatitis C viruses within the hemodialysis unit

The hepatitis B virus (HBV) can be transmitted in the dialysis setting through blood transfusions and environmental surfaces. Transfusion related hepatitis C virus (HCV) infection is very well known, but only recently the environmental transmission of this virus was postulated. In order to study the prevalence, mechanisms of transmission, and the ALT patterns of HBV and HCV infections in hemodialysis and CAPD patients before the implementation of HBV vaccination and HCV screening in the blood bank, we conducted a study from January 1987 to January 1990. Sera from 185 hemodialysis and 124 CAPD patients were stored in this period and later analyzed for HBsAg, anti-HBc, anti-HBs, and anti-HCV (second generation ELISA). The prevalence of any HBV marker was 55.7% (103/185) for hemodialysis patients and 31.5% (39/124) for CAPD patients (hemodialysis vs. CAPD, p < 0.001). The prevalence of positive anti-HCV was 35.1% (65/185) for hemodialysis and 33.9% (42/124) for CAPD patients (not significant). There was a significant association between HBV markers positivity and anti-HCV positivity. The multivariate analysis of risk factors revealed an association of the positivity of each virus with the duration of renal replacement therapy (RRT), number of previous blood transfusions, and past history of hemodialysis treatment. Thus, besides the transfusion-related transmission, hemodialysis environmental transmission may also occur for both viruses. The findings of a high prevalence of both viruses and evidence for environmental transmission in the dialysis setting are of major importance for the planning of future preventive measures.

Quantitation of hepatitis C viral RNA in sera of hemodialysis patients: gender-related differences in viral load

Hepatitis C virus (HCV) infection is common in hemodialysis patients, as determined by antibody assays and qualitative polymerase chain reaction (PCR) analysis of serum HCV RNA. To further characterize HCV infection in this population, we measured the viral load in infected hemodialysis patients by a quantitative, competitive PCR assay (QC-PCR) for HCV RNA. Hepatitis C virus RNA levels were correlated with serologic, biochemical, and demographic features of a cohort of hemodialysis patients. Sera from 208 hemodialysis patients were screened for HCV RNA (5' conserved region) by reverse transcriptase PCR (RT-PCR) and HCV-specific antibody. Forty-four patients were antibody positive (21%); among these patients, 34 (77%) were HCV RNA positive. No viremic, seronegative patients were identified. Hepatitis C virus RNA levels quantitated by QC-PCR ranged from 3 x 10(5) to 10(8) molecules of HCV RNA/mL. Male patients had significantly higher mean and median HCV RNA levels (10(7) molecules/mL) compared with female patients (3.6 x 10(6) molecules/mL and 3 x 10(6) molecules/mL, respectfully; P = 0.02). No other demographic or clinical feature of this cohort correlated with HCV RNA levels. Intravenous drug abuse was the most frequently identified risk factor (29% of seropositive patients) for infection with HCV in this population. No association between HCV RNA levels and hepatic enzyme levels (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transferase, alkaline phosphatase) was apparent. Hepatitis C virus infection is highly prevalent in our hemodialysis population, and hemodialysis patients, particularly males, have high levels of HCV in serum.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis C markers in hemodialysis patients

The prevalence of hepatitis C virus (HCV) infection among the patients of a hemodialysis unit in Taiwan was determined by an immunoblot and reverse transcriptase-polymerase chain reaction algorithm to be 58.8% (67 of 114 patients) after serological surveys with two advanced-generation enzyme-linked immunosorbent assays (ELISAs) for anti-HCV and a C 100-3 single-antigen test. The results of the second-generation ELISAs, the supplementary immunoblot test, and the test for HCV RNA were in good agreement with each other, from 86.0 to 98.2%. The first-generation C 100-3 test lacked the sensitivity of the four other systems. The two advanced-generation screening ELISAs for anti-HCV, a multiple-recombinant-antigen test, the Abbott second-generation ELISA, and a synthetic peptide multiple-antigen test, the UBI HCV EIA, provided reliable and virtually equivalent detection of potentially infected blood. Antibodies to capsid 1 and capsid 2 determinants of the Liatek immunoblot system were the most frequently detected reactivities to HCV in the HCV-infected hemodialysis patients. The percentage of HCV-infected patients with abnormal liver function (alanine aminotransferase level, greater than 100 IU/liter) was higher than that of the uninfected patients. The prevalence of HCV infection was correlated to the duration of hemodialysis treatment and the amount of blood transfused, and the most common transmission mode was thought to be patient-to-patient transmission through the dialysis equipment. Several means of reducing the frequency of transmission between hemodialysis patients are suggested.

Antibodies against non-structural c100/3 and structural core antigen of hepatitis C virus (HCV) in hemodialysis patients

Two groups of patients undergoing hemodialysis (HD) maintenance were evaluated for their antibody response to non-structural c100/3 protein and structural core protein of hepatitis C virus (HCV). Forty-six patients (Group 1) never presented liver abnormalities during HD treatment, while 52 patients (Group 2) had either current or prior liver enzyme elevations. Prevalence rates of 32.6% and 41.3% were found for anti-c100/3 and anti-HCV core antibodies, respectively, in patients with silent infections (Group 1). The rate of anti-c100/3 in patients of Group 2 was 71.15% and reached 86.5% for anti-HCV core antibodies. The recognition of anti-c100/3 and anti-core antibodies was significantly higher in Group 2 than in Group 1. A line immunoassay composed of structural and non-structural peptides was used as a confirmation assay. HBV infection, measured by the presence of anti-HBc antibodies, was observed in 39.8% of the patients. Six were HBsAg chronic carriers and 13 had naturally acquired anti-HBs antibodies. The duration of HD treatment was correlated with anti-HCV positivity. A high prevalence of 96.7% (Group 2) was found in patients who underwent more than 5 years of treatment. Our results suggest that anti-HCV core ELISA is more accurate for detecting HCV infection than anti-c100/3. Although the risk associated with the duration of HD treatment and blood transfusion was high, additional factors such as a significant non-transfusional spread of HCV seems to play a role as well. The identification of infective patients by more sensitive methods for HCV genome detection should help to control the transmission of HCV in the unit under study.