A comprehensive study of the association between hepatitis C virus and glomerulopathy

The Human Virome and Its Crosslink with Glomerulonephritis and IgA Nephropathy

The prokaryotic, viral, fungal, and parasitic microbiome exists in a highly intricate connection with the human host. In addition to eukaryotic viruses, due to the existence of various host bacteria, phages are widely spread throughout the human body. However, it is now evident that some viral community states, as opposed to others, are indicative of health and might be linked to undesirable outcomes for the human host. Members of the virome may collaborate with the human host to retain mutualistic functions in preserving human health. Evolutionary theories contend that a particular microbe's ubiquitous existence may signify a successful partnership with the host. In this Review, we present a survey of the field's work on the human virome and highlight the role of viruses in health and disease and the relationship of the virobiota with immune system control. Moreover, we will analyze virus involvement in glomerulonephritis and in IgA nephropathy, theorizing the molecular mechanisms that may be responsible for the crosslink with these renal diseases.

Burden, Outcome, and Comorbidities of Extrahepatic Manifestations in Hepatitis C Virus Infection

Hepatitis C virus (HCV) is a significant cause of chronic liver diseases worldwide and is associated with negative consequences, including cirrhosis, hepatic decompensation, hepatocellular carcinoma, and increased risk of mortality. In addition to liver-related morbidities, HCV is also associated with several extrahepatic manifestations, including mixed cryoglobulinemia, diabetes mellitus, cardiocerebrovascular disease, lymphoma, and autoimmune diseases. These non-liver-related complications of HCV increase the complexity of this disease and can contribute to the economic burden, morbidity, quality of life, and mortality throughout the world. Therefore, understanding how this virus can contribute to each extrahepatic manifestation is worth investigating. Currently, the advancement of HCV treatment with the advent of direct-acting anti-viral agents (DAAs) has led to a high cure rate as a result of sustained virologic response and tremendously reduced the burden of extrahepatic complications. However, HCV-associated extrahepatic manifestations remain a relevant concern, and this review aims to give an updated highlight of the prevalence, risk factors, associated burdens, and treatment options for these conditions.

The association between hepatitis C virus infection and renal function

BACKGROUND

The association between hepatitis C virus (HCV) infection and chronic kidney disease (CKD) still remains controversial. We aimed to investigate whether HCV really affects renal function, and to analyze the association between clinical effects of CHC and decreased kidney function (assessed by glomerular filtration rate (eGFR) level).

METHODS

An estimated 3360 patients with HCV infection and 3360 age- and sex-matched community-based control individuals without HCV were enrolled (1:1, case and control ratio) in this study between 2004 and 2016. We used the modification of diet in renal diseases to calculate eGFR. Demographic and laboratory parameters were assessed, and appropriate statistical methods were performed for the analysis.

RESULTS

Multivariate logistic regression analysis revealed that serum alanine aminotransferase level (odds ratio [OR] 0.998; 95% confidence interval [CI] 0.997-0.999; P = 0.001), platelet count (OR 0.997; 95% CI 0.995-0.999; p = 0.002), and hypertension (OR 1.31; 95% CI 1.03-1.66; P = 0.027) were significantly associated with HCV infection and serum triglyceride levels (OR 1.001; 95% CI 1.00-1.002; p = 0.005), platelet count (OR 0.996; 95% CI 0.995-0.997; p < 0.001), body mass index (BMI) >25 (OR 1.43; 95% CI 1.23-1.67; p < 0.001), hypertension (OR 1.69; 95% CI 1.42-1.99; p < 0.001), hyperlipidemia (OR 1.32; 95% CI 1.02-1.71; p = 0.035), and diabetes (OR 1.33; 95% CI 1.03-1.71; p = 0.032) were significantly associated with a low eGFR (<90 mL/min/m3) in control subjects. The BMI >25 kg/m2, hypertension, and diabetes were found to be associated with low eGFR interaction with the HCV infection, via a multivariate analysis.

CONCLUSION

Our study found that the patients with HCV infection are associated with a low eGFR compared with non-HCV-infected patients. This association is consistent in obese, diabetic, and hypertensive patients.

Immune disorders and rheumatologic manifestations of viral hepatitis

Infection with hepatotropic viruses is not limited to the liver and can lead to the development of various immunological disorders (the formation of cryoglobulins, rheumatoid factor, antinuclear antibodies, autoantibodies specific for autoimmune hepatitis and primary biliary cholangitis, and others), which can manifest as glomerulonephritis, arthritis, uveitis, vasculitis (cryoglobulinemic vasculitis, polyarteritis nodosa, Henoch-Schonlein purpura, isolated cutaneous necrotizing vasculitis), and other rheumatologic disorders, and be a trigger for the subsequent development of autoimmune hepatitis and primary biliary cholangitis. A further study of the association between autoimmune liver diseases and hepatotropic virus infection would be useful to assess the results of treatment of these associated diseases with antiviral drugs. The relationship of these immune disorders and their manifestations with hepatotropic viruses is best studied for chronic hepatitis B and C. Only isolated cases of these associations are described for hepatitis A. These links are least studied, and are often controversial for hepatitis E, possibly due to their relatively rare diagnoses. Patients with uveitis, glomerulonephritis, arthritis, vasculitis, autoimmune liver diseases should be tested for biomarkers of viral hepatitis, and if present, these patients should be treated with antiviral drugs.

[Chronic kidney injury in patients with liver diseases - Reappraising pathophysiology and treatment options]

Acute and chronic kidney disease concurs commonly with liver disease and is associated with a wide array of complications including dialysis dependency and increased mortality. Patients with liver disease or liver cirrhosis show a higher prevalence of chronic kidney disease. This is attributed to concomitant comorbidities, such as metabolic syndrome, chronic inflammation, hypercoagulability, hyperfibrinolysis, diabetes mellitus and dyslipidaemias. But chronic progressive kidney disease is not always due to hepatorenal syndrome. Beyond that, other diseases or disease entities should be considered. Among them are diabetic nephropathy, secondary IgA nephropathy, hepatitis C -associated membranoproliferative Glomerulonephritis (MPGN) and hepatitis B-associated membranous nephropathy.Coexisting diseases, similar underlying pathophysiologic mechanisms, or simultaneously concurring pathophysiological processes and overlapping clinical manifestations, impede the etiologic diagnosis and corresponding treatment of chronic kidney disease in the setting of chronic liver disease. In this review, we focus on common and rare pathologies, which can lead to chronic kidney disease in this particular patient group and try to summarize the most recent therapeutic modalities.

Evaluation of Renal Disease in Patients With Cirrhosis

Renal dysfunction in cirrhosis is common and is associated with increased mortality. Identifying and treating reversible causes of renal disease can significantly improve outcomes. The etiology, approach, and evaluation of renal disease in this group of patients is similar to the noncirrhosis patient, with a few specific caveats. Renal disease may be unrelated to the cause of cirrhosis (eg, prerenal acute kidney injury, acute tubular necrosis), occur as a manifestation of the same systemic disease responsible for the liver disease (eg, chronic viral hepatitis B and C infection) or as a consequence of cirrhosis (hepatorenal syndrome). Kidney impairment may be underrecognized in patients with cirrhosis due to over-reliance on creatinine-based glomerular filtration rate equations used in clinical practice. The first steps of evaluation for the renal disease include a thorough medical history to identify the underlying cause of cirrhosis and any potential trigger for renal dysfunction, physical examination, and review of prior laboratory records for baseline renal function. Renal imaging and urinalysis should be performed on all cirrhotic patients with renal dysfunction to establish the presence of urinary obstruction, chronicity and intrinsic renal disease.

Transplant glomerulopathy

In the renal allograft, transplant glomerulopathy represents a morphologic lesion and not a specific diagnosis. The hallmark pathologic feature is glomerular basement membrane reduplication by light microscopy or electron microscopy in the absence of immune complex deposits. Transplant glomerulopathy results from chronic, recurring endothelial cell injury that can be mediated by HLA alloantibodies (donor-specific antibodies), various autoantibodies, cell-mediated immune injury, thrombotic microangiopathy, or chronic hepatitis C. Clinically, transplant glomerulopathy may be silent, detectable on protocol biopsy, or present with overt manifestations, including up to nephrotic range proteinuria, hypertension, and declining glomerular filtration rate. In either case, transplant glomerulopathy is associated with reduced graft survival. This review details the morphologic features of transplant glomerulopathy found on light microscopy, immunofluorescence microscopy, and electron microscopy. The pathophysiology of the causes and risk factors are discussed. Clinical manifestations are emphasized and potential therapeutic modalities are examined.

Characterizing hepatitis C virus epidemiology in Egypt: systematic reviews, meta-analyses, and meta-regressions

Egypt is the most affected nation by hepatitis C virus (HCV) and needs a comprehensive characterization of HCV epidemiology to inform the scale-up of treatment and prevention programs. Systematic reviews, meta-analyses, and meta-regressions were conducted. A total of 25 incidence, 259 prevalence, and 47 genotype studies were identified. Incidence and prevalence levels were high across all populations. Genotype 4 accounted for 94.1% of infections with a relative Shannon Diversity Index of only 14.4%. Pooled mean HCV prevalence was estimated at 11.9% (95% CI = 11.1–12.6%) among the general population, 55.6% (95% CI = 49.4–61.7%) among populations at high risk, 14.3% (95% CI = 10.3–18.8%) among populations at intermediate risk, 56.0% (95% CI = 50.4–61.6%) among populations with liver-related conditions, and 35.0% (95% CI = 27.3–43.1%) among special clinical populations. Mean HCV viremic rate was estimated at 66.7% (95% CI = 61.7–71.5%). Meta-regression indicated 6% lower odds for HCV prevalence for each one-year increment in publication year (AOR = 0.94; 95% CI = 0.92–0.96). HCV prevalence is high with evidence for ongoing transmission mainly through healthcare. Genotype diversity is low with genotype 4 dominance. Two-thirds of antibody-positive Egyptians are chronically infected and need treatment. Clinical populations should be prioritized for screening. Despite the large-scale epidemic, prevalence appears to be declining rapidly consistent with a contracting epidemic.

A Case of Hepatorenal Syndrome and Abdominal Compartment Syndrome with High Renal Congestion

BACKGROUND Hepatorenal syndrome (HRS) is a reversible renal impairment that occurs in patients with acute liver failure and advanced liver cirrhosis. HRS is due to a renal vasoconstriction that results from extreme vasodilatation. It is therefore a functional disorder, not associated with structural kidney damage. On the other hand, end-stage liver diseases are often complicated by massive ascites. Massive ascites may cause abdominal compartment syndrome (ACS), which includes impairment of renal blood flow, but there are no reports indicating that kidney lesions caused by ACS may pathologically contribute to end-stage liver diseases. CASE REPORT A 40-year-old man with acute liver failure was admitted to our hospital. He was diagnosed with type 1 HRS and showed ACS at the same time. He died 30 days after admission. There were signs of congestion in the kidneys upon dissection and advanced erythroid fullness in the renal tubules. CONCLUSIONS We report an autopsy case with HRS and ACS diagnosed with a clinical and histopathological consideration of liver and kidney. Further clinical studies are needed to improve management of renal failure in patients with acute liver failure and advanced liver cirrhosis.

Hepatitis C and kidney disease: A narrative review

Hepatitis-C (HCV) infection can induce kidney injury, mostly due to formation of immune-complexes and cryoglobulins, and possibly to a direct cytopathic effect. It may cause acute kidney injury (AKI) as a part of systemic vasculitis, and augments the risk of AKI due to other etiologies. It is responsible for mesangiocapillary or membranous glomerulonephritis, and accelerates the progression of chronic kidney disease due to other causes. HCV infection increases cardiovascular and liver-related mortality in patients on regular dialysis. HCV-infected patients are at increased risk of acute post-transplant complications. Long-term graft survival is compromised by recurrent or de novo glomerulonephritis, or chronic transplant glomerulopathy. Patient survival is challenged by increased incidence of diabetes, sepsis, post-transplant lymphoproliferative disease, and liver failure. Effective and safe directly acting antiviral agents (DAAs) are currently available for treatment at different stages of kidney disease. However, the relative shortage of DAAs in countries where HCV is highly endemic imposes a need for treatment-prioritization, for which a scoring system is proposed in this review. It is concluded that the thoughtful use of DAAs, will result in a significant change in the epidemiology and clinical profiles of kidney disease, as well as improvement of dialysis and transplant outcomes, in endemic areas.

Differential methylation of the promoter and first exon of the RASSF1A gene in hepatocarcinogenesis

AIM

Aberrant methylation of the promoter, P2, and the first exon, E1, regions of the tumor suppressor gene RASSF1A, have been associated with hepatocellular carcinoma (HCC), albeit with poor specificity. This study analyzed the methylation profiles of P1, P2 and E1 regions of the gene to identify the region of which methylation most specifically corresponds to HCC and to evaluate the potential of this methylated region as a biomarker in urine for HCC screening.

METHODS

Bisulfite DNA sequencing and quantitative methylation-specific polymerase chain reaction assays were performed to compare methylation of the 56 CpG sites in regions P1, P2 and E1 in DNA isolated from normal, hepatitic, cirrhotic, adjacent non-HCC, and HCC liver tissue and urine samples for the characterization of hypermethylation of the RASSF1A gene as a biomarker for HCC screening.

RESULTS

In tissue, comparing HCC (n = 120) with cirrhosis and hepatitis together (n = 70), methylation of P1 had an area under the receiver operating characteristics curve (AUROC) of 0.90, whereas methylation of E1 and P2 had AUROC of 0.84 and 0.72, respectively. At 90% sensitivity, specificity for P1 methylation was 72.9% versus 38.6% for E1 and 27.1% for P2. Methylated P1 DNA was detected in urine in association with cirrhosis and HCC. It had a sensitivity of 81.8% for α-fetoprotein negative HCC.

CONCLUSION

Among the three regions analyzed, methylation of P1 is the most specific for HCC and holds great promise as a DNA marker in urine for screening of cirrhosis and HCC.

Outcome of glomerulonephritis in live-donor renal transplant recipients: A single-centre experience

OBJECTIVES

To investigate the frequency and risk factors affecting the incidence of post-transplantation glomerulonephritis (GN) and the impact of GN on the survival of the graft and the patient.

PATIENTS AND METHODS

Patients were classified based on histological findings into three groups. Graft survival was ascertained using the Kaplan-Meier method and significance calculated using log-rank tests. For multivariate analysis the Cox model was used.

RESULTS

Transplant glomerulopathy was the most prevalent glomerular disease in our series followed by recurrent GN and lastly de novo GN. In all, 50% of the de novo GN group had diabetes. The worst graft outcomes were in the recurrent GN group (P = 0.044). Multivariate analysis revealed ageing of the graft and mammalian target of rapamycin (mTOR) immunosuppression as risk factors for development of GN. While, the age of the recipient and donor, anti-lymphocyte globulin induction therapy, and acute rejection were risk factors for poor graft outcomes.

CONCLUSIONS

GN is an important issue after transplantation. Tracking the incidence and progression of histological findings in the graft may help to guide proper management and improve graft outcome.

Association of Hepatitis C Virus Infection with Proteinuria and Glomerular Filtration Rate

AIM

Despite several studies, the extent to which hepatitis C virus (HCV) infection is associated with chronic kidney disease (CKD) remains controversial. Thus, we examined the relationship between HCV and CKD using the continuous National Health and Nutrition Examination Survey (1999-2012).

METHODS

Specimens positive for anti-HCV antibodies were retested and confirmed with recombinant immunoblot assay (RIBA). Proteinuria was defined as urine albumin creatinine ratio > 30 mg/g. CKD was defined as estimated glomerular filtration rate (GFR) < 60 mL/min/1.73 m(2) . We used linear and logistic regression models to examine the association between HCV and outcomes with and without adjustment for age, sex, race, hypertension, diabetes mellitus, and body mass index and accounting for the complex survey design.

RESULTS

Of the 33,729 eligible participants, HCV infection was present in 659 (1.73%). In unadjusted and adjusted analyses, HCV was associated with proteinuria (OR = 1.40, p = 0.01 and OR = 1.50, p = 0.02, respectively). In both unadjusted and adjusted analyses, individuals with HCV had significantly higher GFR than individuals without (1.4 mL/min, p = 0.04 and 2.7 mL/min, p < 0.001, respectively). We did not find an association of HCV with CKD in adjusted or unadjusted analyses.

CONCLUSION

HCV infection is associated with proteinuria and high GFR but not with CKD. The biological mechanism of the observed association needs further study.

Risk factors and their interaction on chronic kidney disease: A multi-centre case control study in Taiwan

Background

Chronic kidney disease (CKD) is highly prevalent in Taiwan. More than two-thirds of end-stage renal disease is associated with diabetes mellitus (DM) or hypertension (HTN). Therefore, the formulation of a special preventative policy of CKD in these patients is essential. This study surveyed 14 traditional risk factors and identified their effects on CKD in patients with HTN/DM and compared these with their effects in the general population.

Methods

This study included 5328 cases and 5135 controls in the CKD/HTN/DM outpatient and health centres of 10 hospitals from 2008 to 2010. Fourteen common effect factors were surveyed (four demographic, five disease and five lifestyle), and their effects on CKD were tested. Significance tests were adjusted by the Bonferroni method. Results of the stratified analyses in the variables were presented with significant heterogeneity between patients with different comorbidities.

Results

Male, ageing, low income, hyperuricemia and lack of exercise habits were risk factors for CKD, and their effects in people with different comorbidities were identical. Anaemia was a risk factor, and there was an additive effect between anaemia and HTN on CKD. Patients with anaemia had a higher risk when associated with HTN [odds ratio (OR) = 6.75, 95 % confidence limit (95 % CI) 4.76–9.68] but had a smaller effect in people without HTN (OR 2.83, 95 % CI 2.16–3.67). The association between hyperlipidaemia-related factors and CKD was also moderated by HTN. It was a significant risk factor in people without HTN (OR = 1.67, 95 % CI 1.38–2.01) but not in patients with HTN (OR =1.03, 95 % CI 0.89–1.19). Hepatitis B, hepatitis C, betel nut chewing, smoking, alcohol intake and groundwater use were not associated with CKD in multivariate analysis.

Conclusions

We considered that patients with HTN and anaemia were a high CKD risk population. Physicians with anaemic patients in outpatient clinics need to recognise that patients who also have HTN might be latent CKD cases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0065-x) contains supplementary material, which is available to authorized users.

Successful treatment of hepatitis E virus-associated cryoglobulinemic membranoproliferative glomerulonephritis with ribavirin

Hepatitis E virus genotype-3 (HEV3) infection can cause chronic hepatitis in immunosuppressed patients and induce extra-hepatic manifestations, such as neurological symptoms, kidney injuries, and immune-mediated thrombocytopenia. Very few cases of HEV-induced kidney manifestations have been reported. Herein, we report, for the first time, a case of de novo membranoproliferative glomerulonephritis that occurred in a kidney transplant patient who developed a chronic HEV3 infection, which was successfully treated with ribavirin.

[Kidney function and liver transplantation]

INTRODUCTION

In liver cirrhosis renal function decreases as well. Hepatorenal syndrome is the most frequent cause of the decrease, but primary kidney failure, diabetes mellitus and some diseases underlying endstage liver failure (such as hepatitis C virus infection) can also play an important role. In liver transplantation several further factors (total cross-clamping of vena cava inferior, polytransfusion, immunosuppression) impair the renal function, too.

AIM

The aim of this study was to analyse the changes in kidney function during the first postoperative year after liver transplantation.

METHOD

Retrospective data analysis was performed after primary liver transplantations (n = 319).

RESULTS

impaired preoperative renal function increased the devepolment of postoperative complications and the first year cumulative patient survival was significantly worse (91,7% vs 69,9%; p<0,001) in this group. If renal function of the patients increased above 60 ml/min/1,73 m2 after the first year, patient survival was better. Independently of the preoperative kidney function, 76% of the patients had impaired kidney function at the first postoperative year. In this group, de novo diabetes mellitus was more frequently diagnosed (22,5% vs 9,5%; p = 0,023).

CONCLUSIONS

Selection of personalized immunosuppressive medication has a positive effect on renal function.

Hepatitis C virus infection in nephrology patients

CONTEXT

Hepatitis C virus (HCV) infection leads to chronic liver disease, but also to extra-hepatic manifestations.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, Pubmed (NLM), LISTA (EBSCO) and Web of Science have been searched.

RESULTS

Herein, we provide an overview of renal diseases related to HCV and their therapies, as well as the treatment options available for HCV (+)/RNA (+) dialysis patients. We will not mention, however, HCV infection-related complications in the post-kidney transplantation setting.

CONCLUSIONS

Extra-hepatic manifestations of HCV infection include mixed cryoglobulinemia, lymphoproliferative disorders, and renal disease. HCV infection has been reported in association with distinct histological patterns of glomerulonephritis in native kidneys.

Low estimated glomerular filtration rate and chronic kidney failure following liver transplant: a retrospective cohort study

BACKGROUND

Patients undergoing orthotropic liver transplant (LTx) often present with chronic kidney disease (CKD). Identification of patients who will progress to end-stage renal disease (ESRD) might allow not only the implementation of kidney protective measures but also simultaneous kidney transplant.

STUDY DESIGN

Retrospective cohort study in adults who underwent LTx at a single center. ESRD, death, and composite of ESRD or death were studied outcomes.

RESULTS

331 patients, who underwent LTx, were followed up for 2.6 ± 1.4 years; 31 (10%) developed ESRD, 6 (2%) underwent kidney transplant after LTx and 25 (8%) remained on chronic hemodialysis. Patients with preoperative eGFR lesser than 60 ml/min per 1.73 m2 had a 4-fold increased risk of developing ESRD after adjustment for sex, diabetes mellitus, APACHE II score, use of nephrotoxic drugs, and severe liver graft failure (HR = 3.95, 95% CI 1.73, 9.01; p = 0.001). Other independent risk factors for ESRD were preoperative diabetes mellitus and post-operative severe liver graft dysfunction.

CONCLUSION

These findings emphasize low eGFR prior to LTx as a predictor for ESRD or death. The consideration for kidney after liver transplant as a treatment modality should be taken into account for those who develop chronic kidney failure after LTx.

De Novo Fibrillary Glomerulonephritis (FGN) in a Renal Transplant with Chronic Hepatitis C

Chronic hepatitis C viremia (HepC) has been associated with numerous renal manifestations both in native kidneys and in the setting of renal transplantation. Glomerulonephritis (GN) of the renal allograft in the setting of HepC most commonly manifests as type 1 membranoproliferative GN (MPGN), either representing recurrence of the original disease or arising de novo. Other GNs were reported after transplantation in the patient with HepC including membranous nephropathy and thrombotic microangiopathy, as well as an enhanced susceptibility to transplant glomerulopathy. We describe the first case of de novo fibrillary GN in a renal transplant patient with HepC where the primary renal disease was biopsy proven type 1 MPGN. We discuss this relationship in detail.

Detection of viral antigens in renal tissue of glomerulonephritis patients without serological evidence of hepatitis B virus and hepatitis C virus infection

OBJECTIVES

Glomerulonephritis is an important extrahepatic manifestation of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection. HBV and HCV infection may be occult, and they are often overlooked by both patients and doctors. The aim of this study was to assess the importance of HBV and HCV infection in glomerulonephritis patients with undetectable HBV surface antigen (HBsAg) and HCV antibody in serum.

METHODS

The HBsAg, the HBV core antigen (HBcAg), and the HCV antigen were detected using immunohistochemistry in frozen renal tissues of 500 glomerulonephritis patients without serological evidence of HBV and HCV infection. Electron microscopy was used to trace the virus particles, and clinicopathological features were also reviewed.

RESULTS

HBsAg or HBcAg was positive in nine out of 500 cases (9/500, 1.8%). Three cases were HBsAg-positive and another six cases were HBcAg-positive. The HCV antigen was found in eight cases (8/500, 1.6%). There was one case of HBV and HCV co-infection (1/500, 0.2%). Under electron microscopy, virus particles were found in the base membrane and cytoplasm of endotheliocytes in the glomerulus. The most common clinical manifestation was nephrotic syndrome (9/18), followed by nephritic syndrome (7/18). Membranous nephropathy was the most common pathological diagnosis (5/18), followed by mesangioproliferative glomerulonephritis (4/18) and IgA nephropathy (4/18).

CONCLUSIONS

Occult HBV and HCV infection might be implicated in HBV- or HCV-associated glomerulonephritis. More attention should be focused on the underlying cause.

Native kidney function following liver transplantation using calcineurin inhibitors: single-center analysis with 20 years of follow-up

INTRODUCTION

The incidence of chronic kidney disease (CKD) in liver transplant recipients has been estimated to be from 18% to 28% at 10 yr after transplantation. As outcomes from liver transplantation continue to improve, long-term native kidney function in these recipients becomes more critical to patient survival.

METHODS

We analyzed 1151 adult, deceased-donor, single-organ primary liver transplantations performed at our center between 7/17/84 and 12/31/07. Analysis of renal function was performed on 972 patients with liver allograft survival >1 yr.

RESULTS

Kaplan-Meier analysis revealed that 3%, 7%, and 18% of liver transplant recipients with allograft survival >1 yr developed end-stage renal disease (ESRD) at five, 10, and 20 yr, respectively. Significant independent risk factors for ESRD included dialysis during the transplant hospitalization, the stage of CKD at one yr, hypercholesterolemia, non-Caucasian race, and hepatitis C as the primary indication for liver transplantation. The initial immunosuppression of essentially all recipients was a calcineurin inhibitor-based regimen.

CONCLUSION

Close, long-term follow-up of liver transplant recipients permits optimal management of liver allograft and native renal function and can lead to excellent long-term outcomes despite a calcineurin inhibitor-based immunosuppressive regimen.

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.

Chronic kidney disease stage progression in liver transplant recipients

BACKGROUND AND OBJECTIVES

There is little information on chronic kidney disease (CKD) stage progression rates and outcomes in liver transplant recipients. Identifying modifiable risk factors may help prevent CKD progression in liver transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective review of 1151 adult, deceased-donor, single-organ primary liver transplants between July 1984 and December 2007 and analyzed kidney outcomes and risk factors for CKD stage progression. Seven hundred twenty-nine patients had an available estimated GFR at 1 year posttransplant to establish a baseline stage. The primary end point was the CKD progression from one stage to a higher stage (lower GFR).

RESULTS

Kaplan-Meier estimates of patient survival were 91%, 74%, and 64% at 5, 10, and 15 years, respectively. Estimates of liver allograft survival were 89%, 71%, and 60% at the same time points. At 1 year, 7%, 34%, 56%, 3%, and 1% of patients were in CKD stages 1, 2, 3, 4, and 5. The incidence of stage progression was 28%, 40%, and 53% at 3, 5, and 10 years. The incidence of ESRD was 2.6%, 7.5%, and 18% at 5, 10, and 20 years. Multivariable Cox regression analyses demonstrated that CKD stage at 1 year, pretransplant diabetes and urinary tract infections/hypercholesterolemia in the first year proved to be independent risk factors for stage progression (hazard ratio 1.9, 0.28, 1.39, and 1.46, respectively, P < 0.05).

CONCLUSIONS

Future studies will determine whether treatment of risk factors in the first posttransplant year prevent CKD progression in liver transplant recipients.

Higher prevalence of chronic kidney disease and shorter renal survival in patients with chronic hepatitis C virus infection

BACKGROUND

The role of hepatitis C virus infection (HCV) in the etiology and progression of chronic kidney disease (CKD) is controversial.

AIM

To measure the prevalence of CKD and evaluate its course in patients with chronic HCV infection.

METHODS

A retrospective analysis was done after excluding patients with nephrolithiasis, structural kidney disease, and those with missing clinical information on 552 anti-HCV-positive patients and 313 patients without known HCV infection matched for age, race, and gender. CKD was defined as estimated glomerular filtration rate value of <60 mL/min/1.73 m(2) and/or persistence of proteinuria (>3 months) on urine analysis by dipstick. Viral load obtained during the initial evaluation was defined as "baseline viral load".

RESULTS

The prevalence of CKD in the anti-HCV-positive group was significantly higher compared to control group [53 (9.6%) vs. 16 (5.1%), P = 0.02]. On multivariate regression analysis, higher age, hypertension, HCV PCR > 7 × 10(5) cps/mL, and diabetes mellitus were significant independent positive predictors, whereas history of interferon treatment was significant independent negative predictor for CKD. Male gender, human immunodeficiency virus status, body weight, intravenous drug use, and HCV genotype were not predictors of CKD. Analysis of renal survival through Kaplan-Meyer curves revealed significantly shorter time to develop CKD (74 vs. 84 months, P < 0.001; log rank) and end-stage renal disease (79.9 vs. 86.5 months, P = 0.005; log rank) in the HCV group compared to the control group.

CONCLUSION

Chronic HCV infection was associated with a significantly higher prevalence of CKD compared with controls, as well as significantly shorter renal survival. A higher baseline viral load is an independent predictor of CKD.

Effect of kidney transplantation on outcomes among patients with hepatitis C

The long-term outcome of kidney transplantation in patients infected with hepatitis C virus (HCV) and end stage renal disease (ESRD) is not well described. We retrospectively identified 230 HCV-infected patients using enzyme immunoassay and nucleic acid testing obtained during the transplant evaluation. Of 207 patients who had a liver biopsy before transplant, 44 underwent 51 follow-up liver biopsies at approximately 5-year intervals either while on the waitlist for a kidney or after kidney transplantation. Advanced fibrosis was present in 10% of patients biopsied, identifying a population that may warrant consideration for combined liver-kidney transplantation. Kidney transplantation does not seem to accelerate liver injury; 77% of kidney recipients who underwent follow-up biopsies showed stable or improved liver histology. There was a higher risk for death during the first 6 months after transplant, but undergoing transplantation conferred a long-term survival advantage over remaining on the waitlist, which was evident by 6 months after transplant (HR, 0.32; 95% CI, 0.17 to 0.62). Furthermore, the risk for death resulting from infection was significantly higher during the first 6 months after transplant (HR, 26.6; 95% CI, 5.01 to 141.3), whereas there was an early (≤6 months) and sustained decrease in the risk for cardiovascular death (HR, 0.20; 95% CI, 0.08 to 0.47). In summary, these data suggest the importance of liver biopsy before transplant and show that kidney transplantation confers a long-term survival benefit among HCV-infected patients with ESRD compared with remaining on the waitlist. Nevertheless, the higher incidence of early infection-related deaths after transplant calls for further study to determine the optimal immunosuppressive protocol.

Chronic viral hepatitis and chronic kidney disease

Chronic kidney disease (CKD) has become a major public health problem worldwide over the past few decades because of the increasing prevalence of hypertension, diabetes mellitus, and elderly individuals in most countries. Chronic viral hepatitis (due to hepatitis B virus (HBV) and hepatitis C virus (HCV)) also poses significant morbidity and mortality globally. Both these viruses can cause CKD and these infections can occur as a consequence of CKD management. CKD patients acquiring HBV or HCV infection have higher morbidity and mortality rates, and the management of these infections among CKD patients with antiviral agents is associated with high rates of adverse effects. The optimal management of CKD associated with HBV and HCV is not well defined because of insufficient data from clinical trials. This review discusses the pathogenesis, clinical characteristics and management issues related to chronic viral hepatitis and CKD.

Renal dysfunction in chronic liver disease

This article is one of ten reviews selected from the Yearbook of Intensive Care and Emergency Medicine 2010 (Springer Verlag) and co-published as a series in Critical Care. Other articles in the series can be found online at http://ccforum.com/series/yearbook. Further information about the Yearbook of Intensive Care and Emergency Medicine is available from http://www.springer.com/series/2855.

Recurent and de novo membranous glomerulopathy after kidney transplantation

The aim of this study was to compare the clinical characteristics of recurrent and de novo membranous glomerulopathy (MG) among a cohort of 614 recipients transplanted between 1989 and 2006. Lupus nephritides were excluded. The diagnosis was established on protocol biopsies performed 1, 2, 4, or 8 years after transplantation or because of proteinuria/nephrotic syndrome and/or an increased serum creatinine level. HCV infection, cryoglobulinemia, monoclonal gammopathy, skin cancers, Kaposi sarcoma, diabetes mellitus, anti-HLA antibodies, and graft survival were not significantly different between the groups. Seventeen MG were diagnosed in 15 patients (2.45% of the whole group), including 6 recurrent MG (35%) and 11 de novo MG (75%). Recurrent MG occurred earlier than de novo MG (15.58 +/- 19.13 vs 49.27 +/- 32.71 months). Recipients with de novo MG were more frequently infected with HCV, which seemed to be the main etiologic factor for de novo MG, and may be linked to a Th2 polarization of the immune response.

Detection of the hepatitis C virus antigen in kidney tissue from infected patients with various glomerulonephritis

BACKGROUND

Several studies have postulated a causal link between hepatitis C virus (HCV) infection and renal diseases through the induction of cryoglobulinaemia. However, the detection of viral antigens within kidneys of HCV-infected patients has proved to be difficult. We studied a cohort of Chinese HCV-infected patients with various glomerulonephritis (GN) in an attempt to detect HCV antigens within their kidneys.

METHODS

Twenty-one patients with various GN were found to be serum HCV-antibody positive (seven serum HCV-RNA positive simultaneously), at the time of renal biopsy, from January 2005 to April 2008 in our hospital. A murine monoclonal antibody against the HCV-NS3 protein was employed to detect the HCV antigen using immunohistochemistry and immunogold labelling. Their clinical and pathological data were collected and further analysed.

RESULTS

The HCV-NS3 antigen was detected in six (6/21, 28.6%) HCV-antibody-positive patients by immunohistochemistry and four out of the six were serum HCV-RNA positive (4/7 in HCV-RNA positive, 57.1%). The HCV antigen mainly displayed a linear or granular deposition along glomerular capillary walls and/or mesangial region. Immunoelectron microscopy showed that the labelling of HCV-NS3 was localized mainly in electronic dense deposits. In the HCV-NS3 detectable patients, three patients were with membranoproliferative glomerulonephritis (MPGN), one with membranous nephropathy, one with IgA nephropathy and one with amyloid nephropathy. The age and urinary protein were significantly greater in HCV-NS3-positive patients than those in HCV-NS3 negative, while serum C3 level was significantly lower in the former group. No significant difference was found in serum ALT, albumin and creatinine level between the two groups.

CONCLUSION

HCV-NS3 antigens could be detected in kidney tissue of HCV-infected patients with various GN, but mainly in those with MPGN and HCV-RNA positive. HCV itself might be involved directly in the pathogenesis of HCV-associated GN.

A nephropathy presenting the microparticles in the glomerular basement membrane in a patient of hepatitis B viral infection

We report here unique electron microscopy findings showing clusters of deposition of spherical and tubular microparticles in a glomerular basement membrane (GBM) of a 46-year-old Japanese male with membranous nephropathy. Another distinct feature was the deep infolding of podocyte membranes into the GBM. Light microscopy showed the ladder formation of the GBM suggesting membranous nephropathy, while the immunofluorescent examination was atypical for the absence of the global capillary deposition of IgG and C3. He had mild liver dysfunction with positive hepatitis B antigen. Antibodies to hepatitis B surface antigen reacted weakly on the GBM in the immunohistochemistry. We suspected the unique findings of this case might be related to the hepatitis B viral infection.

Association of hepatitis C virus infection with prevalence and development of kidney disease

BACKGROUND

Hepatitis C and chronic kidney disease (CKD) are both highly prevalent diseases in the United States. Data showed that hepatitis C may be causally linked to some glomerular diseases, and patients who are positive for hepatitis C have increased risk of albuminuria.

STUDY DESIGN

To determine whether hepatitis C infection is associated with increased likelihood of CKD, we performed retrospective cross-sectional and longitudinal analyses of a large clinical database.

SETTING & PARTICIPANTS

Data for a study population of 13,139 African American and white patients tested for hepatitis C between 1994 and 2004 were extracted from a computerized database from a clinical population of an urban hospital and affiliated clinics.

PREDICTOR

Hepatitis C by means of enzyme-linked immunosorbent assay.

OUTCOME

In cross-sectional analysis, CKD was defined as a minimum estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m(2) by using the 4-variable isotope dilution mass spectrometry-traceable Modification of Diet in Renal Disease Study equation or proteinuria. In longitudinal analysis, CKD was defined as eGFR less than 60 mL/min/1.73 m(2).

MEASUREMENTS

Potential confounders investigated included sex, age, race, human immunodeficiency virus (HIV) status, chronic hypertension, diabetes, and other laboratory test result abnormalities.

RESULTS

3,938 patients (30.0%) were positive for hepatitis C and 2,549 (19.4%) had CKD. Of those with CKD, 1,999 (78.4%) had an eGFR less than 60 mL/min/1.73 m(2), 186 (7.3%) had proteinuria, and 364 (14.3%) had both. In cross-sectional analysis, after controlling for diabetes, hypertension, age, aspartate aminotransferase level, and HIV status, patients who tested positive for hepatitis C had a decreased risk of CKD (odds ratio, 0.69; 95% confidence interval, 0.62 to 0.77). A total of 7,038 subjects without CKD were followed up for a median of 3.5 years. Of these, 2,243 (31.8%) were hepatitis C positive at the onset of follow-up. In longitudinal analysis, after adjustment for age, baseline eGFR, diabetes, hypertension, aspartate aminotransferase level, and HIV status, the hazard ratio for the development of CKD compared with those who were hepatitis C negative was 0.896 (95% confidence interval, 0.790 to 1.015).

LIMITATIONS

Retrospective design, clinical database with missing values, different hepatitis C assays used during the study period, limited data for proteinuria.

CONCLUSIONS

Our results do not support the hypothesis that infection with hepatitis C virus per se is associated with increased risk of having or developing CKD.