Characteristics of hepatitis C in renal transplant candidates

Hepatitis C in hemodialysis patients: current global magnitude, natural history, diagnostic difficulties, and preventive measures

Hepatitis C virus (HCV) infection is a significant cause of morbidity and mortality in hemodialysis (HD) patients. The reported prevalence of HCV among the HD population has varied greatly from 1.9 to 84.6% in different countries in recent years. The length of time on HD is generally believed to be associated with HCV acquisition in HD subjects. Nevertheless, several recent reports failed to recognize any significant role of blood transfusion. Although there are some considerations about the accuracy of serologic testing in detecting HCV in HD patients, the accumulated data in this review suggest the false-negativity rate to be not more than 1.66% (153/9,220). Therefore, substituting virologic for serologic testing in the routine diagnosis of HCV infection in HD patients seems unreasonable. Several phylogenetic analyzes of viral isolates suggested nosocomial patient-to-patient transmission of HCV among HD patients for which the main potential source is believed to be contaminated hands and articles. However, isolation of HCV-infected HD patients and use of dedicated machines are currently unjustified while strict adherence to universal precautions seems to be enough to control disease spread in HD units. The present article is an update on epidemiological and clinical features of HCV in HD population.

Percutaneous liver biopsy is safe in chronic hepatitis C patients with end-stage renal disease

BACKGROUND & AIMS

Liver biopsy is useful for staging fibrosis in chronic hepatitis C (CHC) patients with end-stage renal disease (ESRD) to determine renal transplant eligibility and to make CHC treatment decisions. There is concern about an increased risk associated with percutaneous liver biopsy (PCNB) in ESRD patients. We compared the safety of PCNB in CHC patients with and without ESRD.

METHODS

We reviewed PCNBs performed between 1996 and 2004 for technique, histology, and complications in 78 ESRD patients with CHC and in 241 control patients with CHC and no renal failure, randomly matched for age, sex, and race. Platelet counts, prothrombin, and partial thromboplastin times, but not bleeding times, were checked before biopsy. Deamino-8-D-arginine vasopressin was not given before the biopsy.

RESULTS

The mean age of the patients was 50 years; 72% were male, 97% were African American, and 3% were Caucasian. The control group had a significantly higher proportion of patients with advanced fibrosis (P < .04). Only 1 patient with ESRD (1.3%) developed a moderate complication. Five controls (2.1%) developed complications, 3 of which were severe.

CONCLUSIONS

Severe complications after PCNB are uncommon, and patients with ESRD and CHC are at no increased risk. Testing for bleeding time and the routine use of deamino-8-D-arginine vasopressin are not necessary before PCNB in patients with ESRD.

Simple blood tests as noninvasive markers of liver fibrosis in hemodialysis patients with chronic hepatitis C virus infection

HCV infection is common among patients with end-stage renal disease (ESRD) on hemodialysis, and it has been considered an independent risk factor for mortality in this setting. Although liver biopsy in ESRD patients with HCV infection is useful before kidney transplantation, it carries a high risk of complications. We sought to assess the diagnostic value of noninvasive markers to stage liver fibrosis in 203 ESRD HCV-infected patients. Univariate and multivariate analysis were used to identify variables associated with significant fibrosis (METAVIR F2, F3, or F4 stages). Significant liver fibrosis was observed in 48 patients (24%). Logistic regression analysis identified AST and platelet count as independent predictors of significant fibrosis (P < 0.001 and P = 0.001, respectively). The area under the receiver operating characteristic curve of the AST to platelet ratio index (APRI) for predicting significant fibrosis was 0.801. An APRI < 0.40 accurately identified patients with fibrosis stage 0 or 1 in 93% of the cases (NPV = 93%), and all misclassified subjects were F2. A cutoff > or = 0.95 to confirm significant fibrosis had a PPV of 66%. If biopsy indication was restricted to APRI scores in the intermediate range (> or = 0.40 and < 0.95), 52% of liver biopsies could have been correctly avoided.

CONCLUSION

Stage of liver fibrosis can be reliably predicted in ESRD HCV-infected subjects by simple and widely available blood tests such as AST levels and platelet count. These tests might obviate the requirement for a liver biopsy in a significant proportion of those patients.

Hepatitis C in chronic kidney disease: predialysis patients present more severe histological liver injury than hemodialysis patients?

BACKGROUND

The characteristics of hepatitis C virus (HCV) infection in predialysis patients are poorly understood and they could be different from hemodialysis patients.

AIMS

To evaluate the demographics, laboratory and histological characteristics of chronic HCV infection in predialysis patients and to compare them with those observed in hemodialysis patients.

METHODS

Thirty-nine predialysis patients with chronic HCV infection were compared to HCV-infected hemodialysis patients (ratio of 1:3) in terms of demographics, laboratory and histological characteristics. The fibrosis progression rate (FPR) was calculated as the ratio between fibrosis stage and duration of infection.

RESULTS

Predialysis patients were older (57 +/- 10 vs. 45 +/- 12 years; p < 0.001), presented a higher proportion of elevated alanine aminotransferase (71.8 vs. 41.0%; p = 0.001) and aspartate aminotransferase (64.1 vs. 26.5%; p < 0.001), a higher proportion of interface hepatitis (66.7 vs. 47%; p = 0.033) and more advanced fibrosis (71.8 vs. 16.2%; p = 0.001). Among patients with estimated duration of infection, predialysis patients presented a longer duration of infection (22 vs. 6 years; p < 0.001) and no difference in FPR was observed between groups (p = 0.692).

CONCLUSION

Although predialysis patients with HCV infection present more severe histological injury than hemodialysis patients, this finding probably reflects a longer duration of infection with no evidence supporting that hepatitis C presents a more aggressive course in this group.

Treatment of hepatitis C in special populations

Hepatitis C virus (HCV) is a major cause of liver disease worldwide and is the most common chronic blood-borne infection in the United States. Experience has shown that the epidemiology and the response to treatment of HCV vary in certain patient groups. Differences have been observed in people from different racial and ethnic groups and in patients who have HIV and end-stage renal disease. These groups generally were not included in the early large clinical trials of HCV treatment. This article reviews recent findings in these patients groups and examines future directions.

Is hepatitis C more aggressive in renal transplant patients than in patients with end-stage renal disease?

BACKGROUND

The eventual impact of immunosuppression on the natural history of hepatitis C virus (HCV) infection in patients with end-stage renal disease (ESRD) is still unknown because of the lack of comparative data for HCV-infected patients with ESRD and renal transplant patients. The aim of this study was to compare the biochemical and histological characteristics of chronic HCV infection in renal transplants patients and ESRD patients undergoing hemodialysis.

METHODS

Thirty-eight renal transplant patients and 38 ESRD patients undergoing hemodialysis who were chronically infected with HCV and were matched for gender, age at infection, and estimated time of infection were included in the study. The groups were compared regarding laboratory and histological variables.

RESULTS

Renal transplant patients showed similar alanine aminotransferase and higher gamma-glutamyltransferase levels (P = 0.05) when compared with ESRD patients. Comparative analysis of histological variables revealed a higher proportion of cases with septal fibrosis (P = 0.04) and confluent necrosis (P = 0.01) among transplant-recipient patients. No difference between groups was observed regarding the intensity of portal and periportal inflammatory infiltrates. Steatosis was more prevalent among transplant-recipient patients (P < 0.001). There was no difference between groups regarding the prevalence of lymphoid aggregates or bile duct injury.

CONCLUSION

Renal transplant patients had a larger proportion of cases with septal fibrosis and confluent necrosis than did ESRD patients, suggesting that renal transplantation might modify the natural history of hepatitis C in ESRD patients, leading to a more aggressive liver disease.

Determination of the cut-off value of serum alanine aminotransferase in patients undergoing hemodialysis, to identify biochemical activity in patients with hepatitis C viremia

BACKGROUND

Elevated liver enzymes are infrequent in patients with hepatitis C virus (HCV) infection undergoing chronic hemodialysis (HD), suggesting that the alanine aminotransferase (ALT) is a poor predictor of hepatocellular damage in this population.

OBJECTIVE

To establish a more appropriate cut-off value of ALT to identify biochemical activity due to HCV infection in HD patients.

STUDY DESIGN

A total of 217 patients, with an average age of 51.2 years, were evaluated between January and October 2002; 130 were males (60%). Serum ALT was measured by a kinetic method in five consecutive monthly blood samples, from which an average was obtained and divided by the upper limit of normal (ULN). HCV antibodies were determined using an enzyme immunoassay, the serum HCV-RNA by nested-PCR and HCV genotype by hybridization of the amplified sequence from the 5'-non-coding region. The cut-off value of ALT was obtained from a ROC curve.

RESULTS

Within the 217 patients, 18 (8.3%) were anti-HCV-positive, 17 (7.8%) of whom were also HCV-RNA-positive. Genotype distribution was: 1a=47%; 1b=18%; 3a=35%. Mean ALT/ULN (0.77+/-0.57) of the 18 anti-HCV-positive cases was higher (p<0.001) than the negative group (0.38+/-0.23). The mean ALT/ULN (0.81+/-0.57) of the 17 HCV-RNA-positive cases was also higher (p<0.0001) than the negative cases (0.37+/-0.23). The cut-off value of ALT to distinguish the anti-HCV-positive from negative patients was 0.50% or 50% of the ULN (sensitivity=67%; specificity=83%). According to the HCV-RNA, the cut-off value of ALT was 0.45% or 45% of the ULN (sensitivity=71%; specificity=80%).

CONCLUSION

Reducing the cut-off of ALT by half, enables a better identification of biochemical activity in patients with HCV infection on chronic HD.

Treatment of hepatitis C in special populations

Treatment options for hepatitis C virus (HCV) infection have improved significantly in recent years, however, treatment recommendations came from large clinical trials of highly selected patient populations. HCV infection has increased prevalence in African Americans and also in patients who have HIV infection, end-stage renal disease, and hemophilia. This article reviews recent findings from research in these patient groups and examines future directions and treatment trials.

Clinical presentation of chronic hepatitis C in patients with end-stage renal disease and on hemodialysis versus those with normal renal function

BACKGROUND

The natural history of chronic hepatitis C (CHC) remains to be defined in patients with end-stage renal disease (ESRD).

AIMS

To determine the clinical presentation of CHC and the factors associated with stage III-IV fibrosis in patients with CHC and ESRD.

METHODS

The study included patients with CHC and ESRD (n = 91) or normal renal function (NRF, n = 159). Both groups were matched for mean age, gender, history of alcohol use, and estimated duration of hepatitis C virus (HCV) infection.

RESULTS

Presentation of CHC and ESRD was independently associated with non-Caucasian ethnicity (OR = 3.24, p= 0.0003), a history of diabetes mellitus (DM, OR = 7.911, p < 0.0001), and lower frequencies of being obese (OR = 0.457, p= 0.035), of having hepatic steatosis (OR = 0.372, p= 0.003), and stage III-IV fibrosis (OR = 0.403, p= 0.016). After adjusting for serum levels of alpha-fetoprotein (AFP) and HCV RNA, CHC, and ESRD were independently associated with lower frequencies of elevated alanine aminotransferase (ALT, OR = 0.175, p= 0.02) and aspartate aminotransferase (AST, OR = 0.169, p= 0.04), but higher frequencies of AST/ALT ratio >1 (OR = 7.173, p= 0.002) and hypoalbuminemia (OR = 9.567, p= 0.0007). Compared to patients with NRF and stage III-IV fibrosis, those with ESRD and stage III-IV fibrosis had a significantly higher frequency of a history of DM (OR = 8.014, p= 0.0031) and lower frequency of elevated AST (OR = 0.054, p= 0.004), which were independent of the frequencies of lower levels of ALT and albumin, and AST/ALT ratio >1. In patients with CHC and ESRD, the presence of stage III-IV fibrosis was significantly associated with hepatic steatosis (OR = 4.523, p= 0.012) and thrombocytopenia (OR = 4.884, p= 0.044), which were independent of the frequencies of a history of DM, splenomegaly, and a higher level of AST.

CONCLUSIONS

CHC and ESRD are independently associated with a higher frequency of a history of DM, but lower frequencies of being obese, and having hepatic steatosis, stage III-IV fibrosis, and elevated transaminases. In patients with CHC and ESRD, stage III-IV fibrosis is not associated with a history of DM, but is independently associated with hepatic steatosis and thrombocytopenia.

Lack of Impact of Hepatitis C Virus Coinfection in End-Stage Renal Disease Patients With Hepatitis B Virus Infection

INTRODUCTION

Hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection results in more severe forms of liver disease in nonuremic patients; however, the impact of HCV coinfection is not clearly known in end-stage renal disease (ESRD) patients with HBV infection. We sought to determine the impact of HCV coinfection in HBV-infected ESRD patients.

PATIENTS AND METHODS

The HBsAg-positive ESRD patients evaluated between March 1999 and May 2003 were divided into two groups: group B, HBV infection alone, and group BC, HBV-HCV coinfection (anti-HCV-positive). Both groups were compared regarding epidemiological, laboratory, and histological findings. A liver biopsy was obtained in cases with evidence of viral replication and/or elevated alanine aminotransferase.

RESULTS

One hundred patients (73% men) with mean age of 42 +/- 11 years (55 patients in group B and 45 in group BC) were studied. Comparison between groups showed a difference in time on hemodialysis and duration of infection, which were higher in group BC (P < .001 and P = .001, respectively) and in history of blood transfusion, which was also more frequent in group BC (P = .04). Liver biopsies, obtained from 15 patients in group B and 28 patients in group BC, showed no difference in frequency of septal fibrosis (60% in group B vs 48% in group BC, P = .46) or interface hepatitis (73% vs 71%, P = .99).

CONCLUSIONS

HBV-HCV coinfection was related to a longer time on hemodialysis, longer duration of infection, and history of blood transfusion. Contrary to nonuremic patients, HCV coinfection was not associated with more severe forms of liver disease in ESRD patients.

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.

Meta-analysis: Effect of hepatitis C virus infection on mortality in dialysis

BACKGROUND

The natural history of hepatitis C virus infection among patients on long-term dialysis treatment remains incompletely understood. Efforts to elucidate the natural history of hepatitis C virus in this population are difficult because of the slowly progressive nature of hepatitis C virus with often an unrecognized onset in patients whose life-expectancy is substantially diminished by end-stage renal disease.

AIM

To conduct a systematic review of the published medical literature concerning the impact of hepatitis C virus infection on the survival of patients receiving chronic dialysis. The relative risk of mortality was regarded as the most reliable outcome end-point.

METHODS

We used the random effects model of DerSimonian and Laird to generate a summary estimate of the relative risk for mortality with hepatitis C virus across the published studies.

RESULTS

We identified four clinical trials (2341 unique patients); three (75%) of them were prospective, cohort studies; the fourth was a case-control study. Pooling of study results demonstrated that presence of antihepatitis C virus antibody was an independent and significant risk factor for death in patients on maintenance dialysis. The summary estimate for relative risk was 1.57 with a 95% confidence interval (CI) of 1.33-1.86. A test for homogeneity of the relative risks across the four studies gave a P-value of 0.77. As a cause of death, hepatocellular carcinoma and liver cirrhosis were significantly more frequent among antihepatitis C virus-positive than -negative dialysis patients.

CONCLUSIONS

This meta-analysis demonstrates that antihepatitis C virus-positive patients on dialysis have an increased risk of mortality compared with hepatitis C virus-negative patients. The excess risk of death in hepatitis C virus-positive patients may be at least partially attributed to chronic liver disease with its attendant complications. Clinical trials with extended follow-up are currently under way to assess the effect of hepatitis C virus treatment on the excess risk of mortality in this population.

Transjugular liver biopsy in patients with end-stage renal disease

PURPOSE

To assess the efficacy and safety of transjugular liver biopsy (TJLB) in patients with end-stage renal disease (ESRD) who are undergoing hemodialysis treatment.

MATERIALS AND METHODS

Forty-six consecutive patients with liver disease who were undergoing hemodialysis were included in this study. An 18-gauge Tru-cut transjugular needle with a 20-mm throw was used to obtain liver tissue. All procedures were performed under fluoroscopic guidance. A single pathologist reviewed the biopsy specimens and assessed the size of fragments, number of portal tracts, and adequacy of the specimens for histologic diagnosis. All complications were recorded. The results were compared with the outcomes of percutaneous liver biopsy carried out at our institution in 32 patients with ESRD.

RESULTS

TJLB and percutaneous biopsy techniques yielded adequate specimens for histologic diagnosis in all patients. The mean length of the largest fragments of tissue obtained via the transjugular and percutaneous routes were 16 mm +/- 4 and 14 mm +/- 3, respectively (P = NS). There were no major complications among patients who underwent TJLB. Percutaneous liver biopsy was complicated by hemorrhage in four of 32 patients (12%), three of whom required blood transfusion.

CONCLUSION

TJLB is an effective and safe technique to obtain liver tissue in patients with ESRD and is associated with a lower complication rate than percutaneous liver biopsy.

[Identification of the cutoff value for serum alanine aminotransferase in hepatitis C screening of patients with chronic renal failure on hemodialysis]

The patients with chronic renal failure in hemodialysis present low levels of serum alanine aminotransferases. In order to establish a better cutoff value for ALT in hepatitis C screening of hemodialysis patients, the ALT levels were measured monthly in 235 patients, being excluded those that presented average above the upper limit of normality. The cutoff value was identified by construction of a ROC curve (receiver operating characteristic). Among 202 patients, 15 (7.4%) presented antibodies to hepatitis C virus (anti-HCV) and 187 (92.6%) were anti-HCV negative, with an ALT average of 0.7 and of 0.5 from ULN (p <0.0001), respectively. The better cutoff value for ALT was at 0.6 from ULN, with sensitivity of 67% and specificity of 75% in anti-HCV screening. These results suggest that ULN of ALT could be reduced for 60% from conventional limit, when we are evaluating patients with CRF in hemodialysis.

Hepatitis C and renal disease: an update

Hepatitis C is both a cause and a complication of chronic renal disease. Chronic infection with hepatitis C virus (HCV) can lead to the immune complex syndromes of cryoglobulinemia and membranoproliferative glomerulonephritis (MPGN). The pathogenetic mechanisms for these conditions have not been defined, although they are clearly caused by the chronic viral infection. Management of HCV-related cryoglobulinemia and MPGN is difficult; antiviral therapy is effective in clearing HCV infection in a proportion of patients, but these conditions can be severe and resistant to antiviral therapy. Hepatitis C also is a complicating factor among patients with end-stage renal disease and renal transplants. The source of HCV infection in these patients can be nosocomial. Screening and careful attention to infection control precautions are mandatory for dialysis units to prevent the spread of hepatitis C. Prevention of spread is particularly important in these patients because HCV infection is associated with significant worsening of survival on dialysis therapy, as well as after kidney transplantation. Furthermore, therapy for hepatitis C is problematic, only partially effective, and associated with significant side effects in this population. There are significant needs in both basic and clinical research in the pathogenesis, natural history, prevention, and therapy for hepatitis C in patients with renal disease.

Treatment of Hepatitis C in Solid Organ Transplantation

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