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

Liver biopsy in patients on hemodialysis with hepatitis C virus infection: An important tool

Hepatitis C virus (HCV) infection is commonest blood borne infection amongst hemodialysis patients. Still, there is paucity of data on liver biopsy in these patients. Our center is doing regular liver biopsy in these patients and thus thought of sharing our experience. In this retrospective study, all patients with HCV infection on hemodialysis were subjected to liver biopsy. Serum bilirubin, liver enzyme, HCV-PCR, genotype and viral load measurement were done in all. Biopsy specimen was stained with H and E, Periodic Acid Schiff, Gomori Stain, Masson Trichrome and Perls Stain. International Working Group scoring system of Ishak et al. was used for Grading and Staging. Of the 270 liver biopsies, mean age of patients was 34.05 ± 10.28 years and 233 (85.3%) were males. Mean duration of hemodialysis was 10.9 ± 7.4 months while of known HCV infection was 5.2 ± 4.0 months. Genotype 3 was commonest followed by 1. All had normal bilirubin and 64 (23.1%) had normal ALT. In 37 (13.3%) patients anti-HCV was not detectable. Mean histology grade was 4.03 ± 1.65 (1-10) and stage was 0.75 ± 0.98 (0-3). Only one patient had cirrhosis on histology. Associated hemosiderosis was seen 10 patients. Only minor complications were observed with no mortality. In conclusion, our study shows that in one-fourth patients with active liver disease, liver enzymes are persistently normal in patients on hemodialysis. Further, carefully performed liver biopsy is reasonably safe procedure though some patients do have non-fatal complications. Liver biopsy helps in assessing disease activity, which otherwise cannot be assessed. Histological grade and stage in these patients is usually mild and cirrhosis is rare. Till such time other non-invasive test is validated, liver biopsy will remain an important test in these patients.

Recent advances on hepatitis C virus in dialysis population

Hepatitis C virus (HCV) infection remains common among patients undergoing regular dialysis and good evidence supports the detrimental role of HCV on survival in patients undergoing maintenance dialysis. According to an updated meta-analysis of clinical studies (n=15; 195,370 unique patients on maintenance dialysis), the summary estimate for adjusted relative risk (all-cause mortality) with anti-HCV across the published studies was 1.32 with a 95% Confidence Intervals of 1.24; 1.42, homogeneity assumption was not rejected. Various mechanisms support the excess death risk of HCV-infected patients on regular dialysis, in addition to liver disease-related mortality. The adjusted relative risk for cardiovascular mortality among HCV-infected patients on regular dialysis was 1.26 (95% Confidence Intervals, 1.10; 1.45); the increased cardiovascular mortality in anti-HCV positive patients has been associated in part to malnutrition and chronic inflammation. The current standard of care for HCV in dialysis population is combined antiviral therapy (pegylated interferon plus ribavirin) with a rate of viral response of around 60%. Triple therapy with telaprevir proved to be effective and safe in dialysis patients with HCV but only anecdotal evidence exists. Antiviral treatment of HCV-infected patients on maintenance dialysis could lead to cure the liver damage and the extrahepatic complications. The future availability of all-oral interferon/ribavirin free regimens for antiviral treatment of HCV will help nephrologists to improve survival in this high-risk group.

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.

Chronic liver disease in kidney recipients with hepatitis C virus infection

BACKGROUND

The prevalence of anti-hepatitis C virus (HCV) positive test is higher among patients in dialysis and in kidney recipients than in general population. Hepatitis C virus infection is the main cause of chronic liver disease in renal transplant patients. Liver biopsy and virological analysis were performed to clarify the grade of liver damage in kidney recipients.

METHODS

Renal recipients patients with at least 5 yr under immunosuppression were submitted to clinical and laboratory analysis. Patients who tested anti-HCV positive were candidates to liver biopsy with no regard to transaminase levels.

RESULTS

Forty-five patients tested anti-HCV positive and 42 anti-HCV negative. Twenty-six anti-HCV and RNA-HCV positive patients were submitted to liver biopsy. Seventy-three percentage of these patients presented chronic active hepatitis, from these only one patient presented cirrhosis. Only 29% of the anti-HCV positive group presented elevated alanine aminotransferase levels. Anti-HCV positive patients presented longer previous time on dialysis and less rejection episodes than the group anti-HCV negative (p < 0.05). All anti-HCV positive patients but one tested RNA-HCV positive by polymerase chain reaction (PCR).

CONCLUSIONS

In this series the prevalence of anti-HCV positive is 51.7%. Most of the patients presented liver damage in histology caused by HCV. However, we found only mild or minimal fibrosis and inflammatory activity grade, despite 10 yr of HCV infection and 5 yr of immunosuppressive treatment. Only one patient presented cirrhosis (4%). Performing serial liver biopsies in a long-term follow-up is needed to clarify the impact of HCV infection in renal transplant patients.

Characteristics of hepatitis C in renal transplant candidates

GOALS

To characterize hepatitis C in renal transplant candidates and to compare hepatitis C-related liver disease between patients with end-stage renal disease (ESRD) and well-matched control subjects without renal disease.

BACKGROUND

Hepatitis C is common in dialysis patients and can cause morbidity and mortality in renal transplant recipients. Patients with advanced hepatitis C often are excluded from renal transplantation.

STUDY

Forty-six renal transplant candidates and 46 control subjects matched for age, sex, and race without renal disease were included. Demographic, laboratory, and histologic data were compared between patients with ESRD and control subjects.

RESULTS

Alanine aminotransferase levels were significantly lower in patients with ESRD (p < 0.001). Hepatitis C virus RNA levels were similar between groups. Patients with ESRD had less inflammatory activity (p < 0.001) and a lower proportion of bridging fibrosis or cirrhosis (13%) than control subjects (30%, p = 0.043). Clinical and laboratory features did not predict histologic grade or stage of hepatitis C in patients with ESRD. Two complications of percutaneous liver biopsy occurred per three diagnoses of cirrhosis in patients with ESRD. No complications occurred with transjugular liver biopsy in this group.

CONCLUSIONS

Patients with ESRD had less severe hepatitis C than did control subjects. Clinical measurements did not predict histologic findings in renal transplant candidates. Transjugular liver biopsy should be considered to stage hepatitis C in renal transplant candidates due to the risk of percutaneous biopsy in uremic patients.

Hepatitis infection in haemodialysis patients

SUMMARY: Known hepatitis infections among haemodialysis patients include hepatitis B, hepatitis C, hepatitis G and TT virus. Haemodialysis patients with hepatitis B and/or hepatitis C infection may progress to develop significant morbidity, such as cirrhosis, hepatitic failure or hepatocellular carcinoma. Hepatitis B infection may be treated with α‐interferon or lamivudine. Hepatitis C infection may be treated with α‐interferon, but frequent severe adverse effects were observed, while ribavirin is contraindicated for patients with renal failure. Treatment for hepatitis B and/or hepatitis C are costly, and the risk of post‐transplant reactivation of hepatitis has been reported. Prevention of nosocomial transmission of hepatitis infection with strict infection control and universal precautions is more important. Accumulating evidence suggests that both hepatitis G virus and TT virus (TTV) are not significant causes of liver disease. Routine screening for hepatitis G or TTV viraemia in haemodialysis patients is not indicated at present.

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.