Hepatitis C is a predictor of poorer renal survival in diabetic patients

Hepatitis C in Chronic Kidney Disease: An Overview of the KDIGO Guideline

Hepatitis C virus (HCV) infection is a global health problem with significant health and economic burden, which can lead to chronic kidney disease (CKD) and affect multiple organ systems. In addition, prevalence of hepatitis C remains higher in patients with CKD, including those on chronic hemodialysis and in individuals with a kidney transplant than in the general population. There has been a dramatic shift in the management of hepatitis C since Kidney Disease: Improving Global Outcome (KDIGO) published its 2008 guideline for the prevention, diagnosis and management of hepatitis C in CKD. As a result, KDIGO published in 2018 an update to this guideline. In this narrative review, we present a synopsis of the guideline, including recommendations for screening and detection of HCV in CKD, treatment of HCV in patients with CKD, treatment of HCV before and after kidney transplantation, prevention of HCV transmission in hemodialysis units, and treatment of kidney disease related to HCV infection. We focus on the clinical aspects of using direct acting antivirals (DAAs) in patients with advanced CKD (G4 and G5), those on dialysis and kidney transplant recipients. We emphasize the importance of carefully managing drug-drug interactions between DAAs and immunosuppressive agents. We discuss timing of HCV treatment before vs. after kidney transplantation. Finally, we highlight areas of uncertainty where further research is needed before any definitive recommendations can be made.

Hepatitis c virus and chronic kidney disease

INTRODUCTION

Hepatitis C virus (HCV) infection is associated with an increased incidence and progression of chronic kidney disease (CKD), as well as higher mortality in CKD and renal transplant patients. Direct acting antiviral agents (DAAs) have revolutionized the treatment of HCV, with viral eradication attained in 90-100% of treated patients. DAAs have an excellent safety and tolerability profile in CKD and renal transplant patients.

AREAS COVERED

In this review, we discuss the association of HCV with incidence and progression of CKD as well as its effect on outcomes and mortality. We also discuss the available treatment options in patients with CKD and renal transplant and in HCV-associated glomerular disease.

EXPERT OPINION

The availability of newly available direct acting anti-viral agents has revolutionized the treatment of HCV in persons with advanced CKD and undergoing dialysis. With these regimens, viral eradication can be attained in 90-100% of the treated patients. The safety, tolerability, and efficacy of these drugs in renal transplant patients have also made it possible to use HCV-infected grafts and successful virus eradication at a later stage.

Hepatitis C and Treatment in Patients with Chronic Kidney Disease

Hepatitis C virus (HCV) is associated with increased mortality and morbidity in patients with chronic kidney disease (CKD). The early detection and treatment of Hepatitis C associated with kidney disease is paramount to preventing the progressive loss of kidney function. HCV treatment until the advent of direct acting anti-viral agents (DAAs) was limited to interferon and ribavirin. Interferon and ribavirin treatment resulted in only modest success but with frequent adverse events and poor tolerability. Furthermore, interferon and ribavirin could not be used in certain patient populations including those with advanced CKD, were on dialysis, or those who have received a kidney transplant. DAAs have now made treatment possible in these sub-groups with a sustained viral response (SVR) of 90-100% and minimal side effects. DAAs have helped increase transplant rates by allowing for the use of HCV positive kidneys in recipients who are HCV negative. Although the choice of DAAs should be carefully considered and based on patient characteristics, concomitant medications, and HCV genotype.

Low Complement C4 Predicts Improvement of Kidney Function After Direct-Acting Antiviral Therapy for Hepatitis C Virus

Direct‐acting antiviral therapies (DAAs) may improve kidney function and proteinuria in certain patients with hepatitis C infection (HCV) and chronic kidney disease (CKD). To improve our understanding of HCV‐mediated kidney dysfunction, we aimed to evaluate the baseline predictors of improvement in proteinuria after DAAs in a single‐arm, pilot, clinical trial of ledipasvir 90 mg/sofosbuvir 400 mg once daily for patients with HCV genotype 1 or 4 infection and proteinuric CKD (≥300 mg proteinuria per gram creatinine). Plasma biomarkers of complement system (C3 and C4) and urinary kidney injury biomarkers were measured at baseline, 8 weeks on treatment, 12 weeks following treatment, and 1 year following treatment. We then conducted a retrospective cohort study of patients at Partners Healthcare who had baseline complement component 4 (C4) measured before DAAs for HCV and evaluated the change in estimated glomerular filtration rate (eGFR) before and after therapy. Ten patients with HCV and proteinuric CKD were enrolled in the trial. The mean age was 64 years, 70% male, 70% white, and 30% black. Baseline creatinine was 1.25 mg/dL (SD 0.44), eGFR was 65 mL/min/1.73 m² (SD 29), and proteinuria was 0.98 g/g creatinine (SD 0.7). Sustained virologic response at 12 weeks was achieved by 80% of patients. Patients with low baseline C4 had improved proteinuria, urinary neutrophil gelatinase‐associated lipocalin, and interleukin‐18 after ledipasvir and sofosbuvir treatment. The retrospective study included 50 patients with CKD and HCV. Twenty patients (40%) had low baseline C4; these patients significantly improved their eGFR (+3.4 ± 11.2 mL/min/1.73 m²) compared to those with normal baseline C4 (−4.4 ± 12.2 mL/min/1.73 m²; P = 0.028). Conclusion: Low C4 may be a marker of kidney dysfunction that improves with DAA therapy.

Fisiopatología de la hepatitis C y diabetes mellitus. Hacia la cura de dos epidemias en el siglo XXI

La infección crónica por virus de la hepatitis C (VHC) y la diabetes mellitus (DM) son dos problemas de salud pública que impactan los sistemas de salud, con una alta carga económica global. La infección por VHC produce manifestaciones hepáticas tales como hepatitis, cirrosis y carcinoma hepatocelular; asimismo, se ha involucrado en la patogénesis de manifestaciones extrahepáticas, entre las cuales se ha asociado con alteraciones metabólicas como la DM. Estudios longitudinales y transversales han reportado mayor incidencia y prevalencia de DM en pacientes con infección crónica por VHC. La DM acelera la progresión histológica y clínica en pacientes con infección crónica por VHC y las complicaciones cardiovasculares. Recientemente se ha avanzado en el tratamiento y la introducción de nuevos medicamentos como los antivirales de acción directa, que mejoran el control glucémico en estos pacientes.

Anti-hepatitis C virus therapy in chronic kidney disease patients improves long-term renal and patient survivals

BACKGROUND

Hepatitis C virus (HCV) infection is a documented risk factor for chronic kidney disease (CKD) and progression to end-stage renal disease (ESRD). However, to date there are no reports on the long-term hard endpoints (ESRD and death) of anti-HCV therapy [interferon-based therapy (IBT) or new direct-acting antivirals] in CKD patients. Direct-acting antivirals are not available in Taiwan's single-payer national health insurance database currently released for research. Therefore, we hypothesized that a retrospective analysis of the long-term outcomes of IBT in CKD patients will serve as a proxy for direct-acting antivirals to increase our understanding of progression to ESRD following HCV infection.

AIM

To evaluate the long-term outcomes (ESRD and death) of anti-HCV therapy, especially IBT, in HCV-infected patients with stage 1-5 CKD.

METHODS

We analyzed 93894 Taiwanese adults diagnosed with CKD and without HBV infection. Of these, 4.9% were infected with HCV. Of the 4582 HCV-infected CKD patients, 482 (10.5%) received IBT (treated cohort). They were matched 1:4 with 1928 untreated HCV-infected CKD patients (untreated cohort) by propensity scores and year, which further matched 1:2 by propensity scores with 3856 CKD patients without HCV infection (uninfected cohort). All participants were followed until the occurrence of ESRD, death, or the end of 2012. The association between HCV infection, IBT use, and risks of ESRD and death was analyzed using competing risk analysis.

RESULTS

Taking the uninfected cohort as a reference, the adjusted hazard ratios for ESRD, after adjusting for competing mortality, were 0.34 (0.14-0.84, P = 0.019) and 1.28 (1.03-1.60, P = 0.029) in the treated and untreated cohorts, respectively. The treated cohort had a 29% (0.54-0.92, P = 0.011) decrease in mortality compared to the untreated cohort, in which the mortality was 31% (1.18-1.45, P < 0.001) higher than in the uninfected cohort. The reduced risks of ESRD (0.14, 0.03-0.58, P = 0.007) and death (0.57, 0.41-0.79, P = 0.001) were greatest in HCV-infected CKD patients who received at least 4 mo of IBT, which accounted for 74% of the treated cohort.

CONCLUSION

Adequate anti-HCV therapy in CKD patients improves long-term renal and patient survival.

Association Between Hepatitis C Virus and Chronic Kidney Disease: A Systematic Review and Meta-Analysis

INTRODUCTION AND AIM

The role of hepatitis C virus infection as a risk factor for the development and progression of chronic kidney disease in the general population remains unclear.

MATERIAL AND METHODS

A systematic review of the published medical literature was performed to assess whether positive anti-HCV serologic status is associated with higher frequency of chronic kidney disease in the adult general population. We used a random-effects model to generate a summary estimate of the relative risk of chronic kidney disease (defined by lowered glomerular filtration rate or detectable proteinuria) with HCV across the published studies. Meta-regression and stratified analysis were also carried out.

RESULTS

Forty studies were eligible (n = 4,072,867 patients), and separate meta-analyses were conducted according to the outcome. Pooling results of longitudinal studies (n = 15 studies, n = 2,299,134 unique patients) demonstrated an association between positive anti-HCV serologic status and increased incidence of CKD, the summary estimate for adjusted HR with HCV across the surveys, 1.54 (95% CI, 1.26; 1.87) (P &lt; 0.001). Between-study heterogeneity was observed (Q value by Chi-squared [χ2] test 500.3, P &lt; 0.0001). The risk of chronic kidney disease related to HCV, in the subset of surveys from Asia was 1.45 (1.27; 1.65) (P &lt; 0.001) (no heterogeneity). According to our meta-regression, ageing (P &lt; 0.0001) and duration of follow-up (P &lt; 0.0001) increased the risk of chronic kidney disease among HCV-positive subjects. We observed a relationship between anti-HCV positive serologic status and frequency of proteinuria, adjusted effect estimate of proteinuria with HCV among surveys was 1.633 (95% CI, 1,29; 2.05) (P &lt; 0.001) (n = 10 studies; 315,404 unique patients). However, between-studies heterogeneity was noted (P value by Q test &lt; 0.0001).

CONCLUSION

An association between HCV infection and increased risk of chronic kidney disease in the general population exists. The mechanisms underlying such association are currently under active investigation.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

The association of hepatitis C infection with the onset of CKD and progression into ESRD

Hepatitis C virus (HCV) infection is not only an important cause of chronic liver disease, but extrahepatic manifestations are common and include chronic kidney disease (CKD). HCV is classically associated with cryoglobulinemic glomerulonephritis in the context of mixed cryoglobulinemia syndrome, but other glomerular diseases also occur and may be significantly under-recognized. HCV may cause glomerular disease by immune complex deposition; however, other potential mechanisms by which HCV promotes CKD include a direct cytopathic effect of the virus on renal tissue, and by its association with accelerated atherosclerosis, insulin resistance, and chronic inflammation. Epidemiologic studies show HCV infection confers an increased risk of incident CKD and accelerates progression of CKD to end-stage renal disease (ESRD) in the general population, as well as subpopulations including diabetic patients, those coinfected with human immunodeficiency virus (HIV), and kidney transplant recipients. Patients with CKD and HCV infection experience inferior clinical outcomes, including poorer quality of life and an increased risk of mortality. Treatment with interferon-based regimens is associated with decreased risk of incident CKD and ESRD, though prior studies are limited by the small number of patients with HCV and CKD who underwent treatment. With the advent of new, well-tolerated direct-acting antiviral combinations that are not cleared by the kidneys, it is possible to treat all genotypes of HCV infection in patients with CKD and ESRD. More data on the effect of direct-acting antivirals on CKD incidence and progression are necessary. However, there is every expectation that with improved access to HCV treatment, the burden of CKD in patients with HCV could significantly decline.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

Kidney Function Decline in Patients with CKD and Untreated Hepatitis C Infection

BACKGROUND AND OBJECTIVES

Studies evaluating the role of hepatitis C viral (HCV) infection on the progression of CKD are few and conflicting. Therefore, we evaluated the association of untreated HCV on kidney function decline in patients with stage 3-5 CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective cohort study included members of Kaiser Permanente Southern California and Kaiser Permanente Mid-Atlantic States aged ≥18 years, with incident HCV and CKD diagnoses from January 1, 2004 to December 31, 2014. We used generalized estimating equations to compare the rate of change in eGFR between those with HCV and CKD versus CKD alone, adjusting for covariates. Cox proportional hazards models compared the risk of 25% decrease in eGFR and ESKD (defined as progression to eGFR<15 ml/min per 1.73 m2 on two or more occasions, at least 90 days apart) in those with HCV and CKD versus CKD alone, adjusting for covariates.

RESULTS

We identified 151,974 patients with CKD only and 1603 patients with HCV and CKD who met the study criteria. The adjusted annual decline of eGFR among patients with HCV and CKD was greater by 0.58 (95% confidence interval [95% CI], 0.31 to 0.84) ml/min per 1.73 m2, compared with that in the CKD-only population (HCV and CKD, -1.61; 95% CI, -1.87 to -1.35 ml/min; CKD only, -1.04; 95% CI, -1.06 to -1.01 ml/min). Adjusted for covariates, the hazard for a 25% decline in eGFR and for ESKD were 1.87 (95% CI, 1.75 to 2.00) and 1.93 (95% CI, 1.64 to 2.27) times higher among those with HCV and CKD, respectively, compared with those with CKD only.

CONCLUSIONS

Untreated HCV infection was associated with greater kidney function decline in patients with stage 3-5 CKD.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

Management of hepatitis C virus infection in patients with chronic kidney disease: position statement of the joint committee of Italian association for the study of the liver (AISF), Italian society of internal medicine (SIMI), Italian society of infectious and tropical disease (SIMIT) and Italian society of nephrology (SIN)

Hepatitis C virus (HCV) infection is now considered a systemic disease due to the occurrence of extra-hepatic manifestations. Among these, the renal involvement is frequent. HCV infection, in fact, is strongly associated with proteinuria and chronic kidney disease (CKD) and negatively affects the prognosis of renal patients. In the last few years, availability of more specific and effective drugs against HCV has dramatically changed the clinical course of this disease. These drugs may provide further advantages in the CKD population as a whole by reducing progression of renal disease, mortality rate and by increasing the survival of graft in renal transplant recipients. The strict pathogenetic and prognostic link between HCV infection and CKD requires an ongoing relationship among the healthcare professionals involved in the treatment of both HCV infection and CKD. Therefore, Scientific Societies involved in the care of this high-risk population in Italy have organized a joint expert panel. The aim of the panel is to produce a position statement that can be used in daily clinical practice for the management of HCV infected patients across the whole spectrum of renal disease, from the conservative phase to renal replacement treatments (dialysis and transplantation). Sharing specific evidence-based expertise of different professional healthcare is the first step to obtain a common ground of knowledge on which to instate a model for multidisciplinary management of this high-risk population. Statements cover seven areas including epidemiology of CKD, HCV-induced glomerular damage, HCV-related renal risk, staging of liver disease in patients with CKD, prevention of transmission of HCV in hemodialysis units, treatment of HCV infection and management of HCV in kidney transplantation.

Hepatitis C and Its Metabolic Complications in Kidney Disease

INTRODUCTION

Evidence has been accumulated during the last decade showing that HCV infection plays an important activity at hepatic and extra-hepatic level. Chronic HCV is associated with a large spectrum of extra-hepatic manifestations including lympho-proliferative diseases and metabolic abnormalities (such as insulin resistance and fatty liver disease).

MATERIAL AND METHODS

We have performed an extensive review of the medical literature regarding the increased risk of cardiovascular and kidney disease that has been observed in various groups of HCV-infected patients. The potential link between such increased risk and the metabolic consequences of chronic HCV infection has been explored.

RESULTS

According to a systematic review with a meta-analysis of longitudinal studies (n = 9 clinical observational studies; n = 1,947,034 unique patients), we found a strong relationship between positive anti-HCV serologic status and increased incidence of chronic kidney disease in the adult general population, the summary estimate for adjusted hazard ratio was 1.43 (95% confidence intervals, 1.23; 1.63, P = 0.0001) (random-effects model) in anti-HCV positive patients. In another meta-analysis of clinical observational studies (n = 145,608 unique patients on long term dialysis; n = 14 observational studies), anti-HCV sero-positive status was an independent and significant risk factor for death in patients on maintenance dialysis. The summary estimate for adjusted relative risk (all-cause mortality) was 1.35 with a 95% confidence interval (CI) of 1.25; 1.47 (P &lt; 0.01) in anti-HCV positive patients on maintenance dialysis. An updated and stratified analysis (n = 4 studies, n = 91,916 patients on maintenance dialysis) resulted in an adjusted HR for cardiovascular mortality among anti-HCV positive patients of 1.21 (95% CI, 1.06; 1.39) (P &lt; 0.01); the homogeneity assumption was not rejected. The mechanisms underlying such relationships remain unclear; it has been suggested that HCV promotes atherogenesis through direct and indirect mechanisms.

CONCLUSIONS

Clinical trials are under way to assess whether the clearance of HCV RNA from serum by direct-acting antiviral drugs reduces all cause or disease-specific (cardiovascular) mortality among patients on maintenance dialysis.

Hepatitis C viral load, genotype, and increased risk of developing end-stage renal disease: REVEAL-HCV study

The association between hepatitis C virus (HCV) infection and end-stage renal disease (ESRD) remains controversial without considering the role of HCV viral load and genotype. This study aimed to determine whether HCV RNA level and genotype affect the risk of developing ESRD. Between 1991 and 1992, 19,984 participants aged 30-65 years were enrolled in a community-based prospective cohort study in Taiwan. Chronic HCV infection was defined by detectable HCV viral load. ESRD was determined as the need for chronic dialysis or renal transplantation. Conventional Cox proportional hazard and competing risk models were used to determine the hazard ratio (HR) for ESRD. After a median follow-up of 16.8 years, 204 cases were detected during 319,474 person-years. The incidence rates of ESRD for nonchronically HCV-infected and chronically HCV-infected patients were 60.2 and 194.3 per 100,000 person-years, respectively. The multivariable HR was 2.33 (95% confidence interval [CI] 1.40-3.89) when comparing patients with and without chronic HCV infection. Patients with low and high HCV RNA levels were at higher risk of ESRD than those who were nonchronically HCV-infected (HR, 2.11, 95% CI 1.16-3.86, and HR, 3.06, 95% CI 1.23-7.58; P_trend < 0.001). This association remained robust after taking pre-ESRD death as a competing event for ESRD. Patients with HCV genotype 1 tended to have a higher risk of developing ESRD (HR, 3.60 95% CI 1.83-7.07) compared with nonchronically HCV-infected subjects.

CONCLUSIONS

This study reveals that chronic HCV infection is associated with an increased risk of developing ESRD and suggests that elevated serum levels of HCV RNA (>167,000 IU/mL) and HCV genotype 1 are strong predictors of ESRD, indicating clinical implications for the management of chronic HCV. (Hepatology 2017;66:784-793).

International therapeutic guidelines for patients with HCV-related extrahepatic disorders. A multidisciplinary expert statement

Hepatitis C virus (HCV) is both hepatotrophic and lymphotropic virus that causes liver as well extrahepatic manifestations including cryoglobulinemic vasculitis, the most frequent and studied condition, lymphoma, and neurologic, cardiovascular, endocrine-metabolic or renal diseases. HCV-extrahepatic manifestations (HCV-EHMs) may severely affect the overall prognosis, while viral eradication significantly reduces non-liver related deaths. Different clinical manifestations may coexist in the same patient. Due to the variety of HCV clinical manifestations, a multidisciplinary approach along with appropriate therapeutic strategies are required. In the era of interferon-free anti-HCV treatments, international recommendations for the therapeutic management of HCV-EHMs are needed. This implies the need to define the best criteria to use antivirals and/or other therapeutic approaches. The present recommendations, based on qualified expert experience and specific literature, will focus on etiological (antiviral) therapies and/or traditional pathogenetic treatments that still maintain their therapeutic utility.

International diagnostic guidelines for patients with HCV-related extrahepatic manifestations. A multidisciplinary expert statement

Hepatitis C virus (HCV) infection is responsible for both hepatic and extra-hepatic disorders (HCV-EHDs); these latter are correlated on one hand clearly with HCV lymphotropism causing immune-system dysregulation as well as with viral oncogenic potential, and on the other hand probably with chronic inflammatory status causing cardio-metabolic complications as well as neurocognitive disturbances. The spectrum of HCV-EHDs ranges from mild or moderate manifestations, such as arthralgia, sicca syndrome, peripheral neuropathy, to severe, life-threatening complications, mainly vasculitis and neoplastic conditions. Given the clinical heterogeneity of HCV-EHDs, HCV-infected individuals are inevitably referred to different specialists according to the presenting/prevalent symptom(s); therefore, the availability of comprehensive diagnostic guidelines is necessary for a patient's whole assessment that is decisive for early diagnosis and correct therapeutic approach of various hepatic and HCV-EHDs, regardless of the specific competencies of different physicians or referral centers. In this respect, a multidisciplinary network of experts, the International Study Group of Extrahepatic Manifestations Related to Hepatitis C Virus Infection (ISG-EHCV), was organized with the intention to formulate diagnostic guidelines for the work-up of possible HCV-EHDs. There was a broad consensus among ISG-EHCV members on the proposed guidelines, which essentially are based on two main levels of patient's assessment. At the referral stage, it is proposed that all patients with HCV infection should be invariably examined by means of first-line diagnostic procedures including virological and hepatic parameter evaluation, as well as the detection of clinical findings that may suggest one or more HCV-EHDs. This preliminary assessment should reveal specific HCV-EHDs, which will be deeper analyzed by means of second-line, targeted investigations. The proposed multidisciplinary expert statement represents the first attempt to draw comprehensive diagnostic guidelines for HCV-infected individuals encompassing the entire spectrum of HCV-related disorders, namely typical hepatic manifestations along with less common, often unpredictable HCV-EHDs. The HCV-EHDs may compromise to a substantial degree the overall disease outcome in a significant number of HCV-infected individuals that renders their timely identification and treatment an imperative. In conclusion, the application of standardized but thorough diagnostic guidelines of HCV-EHDs is advisable at the referral stage as well as during the follow-up period of HCV infected patients. It is envisioned that the proposed strategy will result in improvement of clinical outcomes in such patients.

Impact of HCV Infection on Diabetes Patients for the Risk of End-Stage Renal Failure

Both diabetes mellitus (DM) and hepatitis C virus infection (HCVI) are associated with chronic kidney disease (CKD). The aim of this study was to evaluate whether HCVI increases the risk of end-stage renal disease (ESRD) in patients with DM.The National Health Insurance Research database of Taiwan was used to conduct this study. After excluding patients with a prior history of CKD, all patients with a first diagnosis of DM from January 1, 2000 to December 31, 2002 were enrolled. The patients who also had HCVI were defined as index cases (HCV group, n = 9787). A comparison cohort at a 1:1 ratio of random incident patients with DM without HCVI matched by age, sex, age at the diagnosis of DM, duration between the diagnosis of DM and the index date, and various comorbidities through propensity score matching were recruited (non-HCV group, n = 9787). The patients were followed until December 31, 2011.The cumulative incidence rate of developing ESRD was significantly higher in the HCV(+) group than in the non-HCV group (P = 0.008). The incidence rate ratio (IRR) for the risk of ESRD was also significantly higher in the HCV(+) group (IRR: 1.44; 95% CI: 1.09-1.89) than in the non-HCV group, especially for those with a younger age (<50 years; IRR: 2.05; 95% CI: 1.22-3.45) and HCVI within 4 years after the diagnosis of DM (IRR: 1.85; 95% CI: 1.16-2.97). After adjusting for comorbidities in multivariate Cox proportional hazard regression analysis, HCVI (HR: 1.47; 95% CI: 1.11-1.93) was an independent factor for developing ESRD in the patients with DM. After starting dialysis for ESRD, the HCV(+) patients had a similar mortality rate to those without HCVI (P = 0.84).HCVI increases the risk of developing ESRD in patients with DM, especially in younger patients and in those who develop HCVI sooner after a diagnosis of DM.

Hepatitis C Virus Infection Increases the Risk of Developing Chronic Kidney Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND RATIONALE

Chronic kidney disease and hepatitis C virus are prevalent in the general population worldwide, and controversy exists about the impact of HCV infection on the development and progression of kidney disease.

DESIGN

A systematic review of the published medical literature was made to assess whether positive anti-HCV serologic status plays an independent impact on the development of chronic kidney disease in the adult general population. We used a random-effects model to generate a summary estimate of the relative risk of chronic kidney disease (defined by reduced glomerular filtration rate or detectable proteinuria) with HCV across the published studies. Meta-regression and stratified analysis were also conducted.

RESULTS

Twenty-three studies (n = 2,842,421 patients) were eligible, and separate meta-analyses were performed according to the outcome. Pooling results of longitudinal studies (n = 9; 1,947,034 unique patients) demonstrated a relationship between positive HCV serologic status and increased incidence of chronic kidney disease, the summary estimate for adjusted hazard ratio was 1.43 (95% confidence interval 1.23; 1.63, P = 0.0001), and between-studies heterogeneity was noted (P value by Q test <0.0001). The risk of the incidence of chronic kidney disease associated with HCV, in the subset of Asian surveys, was 1.31 (95% confidence interval 1.16; 1.45) without heterogeneity (P value by Q test = 0.6). HCV positive serology was an independent risk factor for proteinuria; adjusted odds ratio, 1.508 (95% confidence intervals 1.19; 1.89, P = 0.0001) (n = 6 studies; 107,356 unique patients).

CONCLUSIONS

HCV infection is associated with an increased risk of developing chronic kidney disease in the adult general population.

Current Management of Chronic Hepatitis B and C in Chronic Kidney Disease

The landscape of therapeutic options for hepatitis B and C has changed drastically over the course of 2 decades. There are now novel, effective, well-tolerated, oral antiviral agents being used to successfully control chronic hepatitis B (HBV) infections and cure chronic hepatitis C (HCV) infections. However, patients with CKD were rarely included in the Phase II and III randomized trials for these medications. This paucity of data and the high prevalence of comorbidities associated with CKD pose distinct challenges to physicians treating chronic hepatitis B virus and hepatitis C virus infections in the setting of kidney insufficiency/failure. Thus, this review will attempt to summarize the current data regarding novel antiviral therapies for HBV and HCV in the CKD population.

A Taiwanese Nationwide Cohort Study Shows Interferon-Based Therapy for Chronic Hepatitis C Reduces the Risk of Chronic Kidney Disease

Hepatitis C virus (HCV) infection is a risk factor for chronic kidney disease (CKD). However, it remains unclear whether interferon-based therapy (IBT) for HCV was associated with reduced risk of CKD.From the Taiwan National Health Insurance Research Database, we identified 919 patients who received 3 months or more of IBT as our treated cohort. This cohort was propensity score-matched 1:4 with 3676 controls who had never received IBT for HCV infection (untreated cohort). Cumulative incidences of and hazard ratios (HRs) for CKD were calculated after adjusting for competing mortality.In the matched HCV cohort, the risk of CKD was significantly lower in the treated cohort (7-year cumulative incidence, 2.6%; 95% confidence interval [CI], 0.7%-6.9%) than in the untreated cohort (4%; 95% CI, 3.5%-5.2%) (P < 0.001), with an adjusted HR of 0.42 (95% CI, 0.20-0.92; P = 0.03). The results also held in the overall HCV cohort. The number needed to treat for 1 fewer CKD at 7 years was 58. The reduced risk of CKD was greatest (0.35; 0.14-0.87; P = 0.024) in HCV-infected patients who received 6 months or more of IBT. Multivariable stratified analysis verified that greater risk reduction of CKD was present in HCV-infected patients with hyperlipidemia, diabetes, hypertension, and those without coronary heart disease.In conclusion, IBT, especially for 6 or more months, is associated with reduced risk of CKD in HCV-infected patients. Hyperlipidemia, diabetes, hypertension, and coronary heart disease can modify this association.

Novel evidence on hepatitis C virus-associated glomerular disease

A large spectrum of renal pathology is associated with hepatitis C virus (HCV). According to novel evidence, occult HCV infection (HCV-RNA in peripheral blood mononuclear cells or in serum after ultracentrifugation) could be involved in the pathogenesis of glomerular nephropathy among patients negative for conventional markers of HCV. Additional studies with appropriate size and technology are in progress to confirm the relationship between occult HCV and glomerular disease, which has multiple implications from the clinical standpoint.

Association of hepatitis C viral infection with incidence and progression of chronic kidney disease in a large cohort of US veterans

An estimated 4 million Americans have been exposed to the hepatitis C virus (HCV). The risks of incident and progressive chronic kidney disease and of mortality in patients with normal kidney function infected with HCV are unclear. In a nationally representative cohort of 100,518 HCV(+) and 920,531 HCV(-) US veterans with normal baseline estimated glomerular filtration rate (eGFR), we examined the association of HCV infection with (1) all-cause mortality, (2) incidence of decreased kidney function (defined as eGFR <60 mL/min/1.73 m(2) and 25% decrease in eGFR), (3) end-stage renal disease, and (4) rate of kidney function decline. Associations were examined in naive and adjusted Cox models (for time-to-event analyses) and logistic regression models (for slopes), with sequential adjustments for important confounders. Propensity-matched cohort analysis was used in sensitivity analyses. The patients' age was 54.5 ± 13.1 (mean ± standard deviation) years, 22% were black, 92% were male, and the baseline eGFR was 88 ± 16 mL/min/1.73 m(2) . In multivariable adjusted models HCV infection was associated with a 2.2-fold higher mortality (fully adjusted hazard ratio = 2.17, 95% confidence interval [CI] 2.13-2.21), a 15% higher incidence of decreased kidney function (adjusted hazard ratio = 1.15, 95% CI 1.12-1.17), a 22% higher risk of steeper slopes of eGFR (adjusted odds ratio = 1.22, 95% CI 1.19-1.26), and a 98% higher hazard of end-stage renal disease (adjusted hazard ratio = 1.98, 95% CI 1.81-2.16). Quantitatively similar results were found in propensity-matched cohort analyses.

CONCLUSIONS

Infection with HCV is associated with higher mortality risk, incidence of decreased kidney function, and progressive loss of kidney function; randomized controlled trials are warranted to determine whether treatment of HCV infection can prevent the development and progression of chronic kidney disease and improve patient outcomes.

Hepatitis C virus infection and type 1 and type 2 diabetes mellitus

Hepatitis C virus (HCV) infection and diabetes mellitus are two major public health problems that cause devastating health and financial burdens worldwide. Diabetes can be classified into two major types: type 1 diabetes mellitus (T1DM) and T2DM. T2DM is a common endocrine disorder that encompasses multifactorial mechanisms, and T1DM is an immunologically mediated disease. Many epidemiological studies have shown an association between T2DM and chronic hepatitis C (CHC) infection. The processes through which CHC is associated with T2DM seem to involve direct viral effects, insulin resistance, proinflammatory cytokines, chemokines, and other immune-mediated mechanisms. Few data have been reported on the association of CHC and T1DM and reports on the potential association between T1DM and acute HCV infection are even rarer. A small number of studies indicate that interferon-α therapy can stimulate pancreatic autoimmunity and in certain cases lead to the development of T1DM. Diabetes and CHC have important interactions. Diabetic CHC patients have an increased risk of developing cirrhosis and hepatocellular carcinoma compared with non-diabetic CHC subjects. However, clinical trials on HCV-positive patients have reported improvements in glucose metabolism after antiviral treatment. Further studies are needed to improve prevention policies and to foster adequate and cost-effective programmes for the surveillance and treatment of diabetic CHC patients.

Hepatitis C virus associated glomerulopathies

Hepatitis C virus (HCV) infection is a systemic disorder which is often associated with a number of extrahepatic manifestations including glomerulopathies. Patients with HCV infection were found to have a higher risk of end-stage renal disease. HCV positivity has also been linked to lower graft and patient survivals after kidney transplantation. Various histological types of renal diseases are reported in association with HCV infection including membranoproliferative glomerulonephritis (MPGN), membranous nephropathy, focal segmental glomerulosclerosis, fibrillary glomerulonephritis, immunotactoid glomerulopathy, IgA nephropathy, renal thrombotic microangiopathy, vasculitic renal involvement and interstitial nephritis. The most common type of HCV associated glomerulopathy is type I MPGN associated with type II mixed cryoglobulinemia. Clinically, typical renal manifestations in HCV-infected patients include proteinuria, microscopic hematuria, hypertension, acute nephritis and nephrotic syndrome. Three approaches may be suggested for the treatment of HCV-associated glomerulopathies and cryoglobulinemic renal disease: (1) antiviral therapy to prevent the further direct damage of HCV on kidneys and synthesis of immune-complexes; (2) B-cell depletion therapy to prevent formation of immune-complexes and cryoglobulins; and (3) nonspecific immunosuppressive therapy targeting inflammatory cells to prevent the synthesis of immune-complexes and to treat cryoglobulin associated vasculitis. In patients with moderate proteinuria and stable renal functions, anti-HCV therapy is advised to be started as pegylated interferon-α plus ribavirin. However in patients with nephrotic-range proteinuria and/or progressive kidney injury and other serious extra-renal manifestations, immunosuppressive therapy with cyclophosphamide, rituximab, steroid pulses and plasmapheresis should be administrated.

Hepatitis C virus infection increases risk of developing end-stage renal disease using competing risk analysis

Background

Chronic kidney disease (CKD) and hepatitis C virus (HCV) infection are closely linked and both increase patient mortality. The association of HCV and risk of developing end-stage renal disease (ESRD) has not been analyzed with competing risk model.

Method

We enrolled a prospective cohort of 4,185 patients (mean age, 62 years; 41% female) registered in the CKD integrated care program at two affiliated hospitals of Kaohsiung Medical University in Taiwan between November 11, 2002 and May 31, 2009. With competing risk model, we analyzed the association of HCV infection, defined by seropositive of anti-HCV antibody, and hepatitis B virus (HBV) infection, defined by seropositive of HBV surface antigen, with the risk of entering ESRD.

Results

The prevalence of HCV infection was 7.6% and it increased with the CKD stages (trend test, P<0.001), while the prevalence of HBV infection was 7.4% and no specific trend among CKD stages (tend test, P = 0.1). During the 9,101 person-year follow-up period, there were 446 death and 1,205 patients entering ESRD. After adjusting death as the competing risk, the estimated 5-year cumulative incidence rate of ESRD among patients with and without HCV infection were 52.6% and 38.4%, respectively (modified log-rank, P<0.001). Multivariable analysis showed that HCV infection, but not HBV infection, had higher risk of developing ESRD compared with cases without infection (HCV, HR: 1.32, 95% CI: 1.07–1.62; HBV, HR: 1.10, 95% CI: 0.89–1.35). Subgroup analyses showed consistent results.

Conclusions

With death-adjusted competing risk analysis, HCV infection is associated with an increased risk of developing ESRD in CKD cohort.

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.

Diabetes and its comorbidities--where East meets West

Fetal programming associated with in utero exposure to maternal stress is thought to alter gene expression, resulting in phenotypes that promote survival in a pathogen-rich and nutrient-poor environment but substantially increase the risk of cardiovascular, metabolic and renal disorders (such as diabetes mellitus) in adults with obesity. These (epi)genetic phenomena are modified by environmental and socioeconomic factors, resulting in multiple subphenotypes and clinical consequences. In individuals from areas undergoing rapid economic development, which is associated with a transition from communicable to noncommunicable diseases, an efficient innate immune response can exaggerate obesity-associated inflammation. By contrast, in individuals with a genetic predisposition to autoimmune or monogenic diabetes mellitus, obesity can lead to atypical presentation of diabetes mellitus, termed 'double diabetes mellitus'. The increasingly young age at diagnosis of diabetes mellitus in developing countries results in prolonged exposure to glucolipotoxicity, low-grade inflammation and increased oxidative stress, which put enormous strain on pancreatic β cells and renal function. These conditions create a metabolic milieu conducive to cancer growth. This Review discusses how rapid changes in technology and human behaviour have brought on the global epidemic of metabolic diseases, and suggests that solutions will be based on using system change, technology and behavioural strategies to combat this societal-turned-medical problem.

TLR3-dependent immune regulatory functions of human mesangial cells

In glomerulonephritis, the migration of inflammatory cells into the glomerulus is an important step in disease initiation and progression. The viral receptor Toll-like receptor 3 (TLR3) is known to play a role in virus-associated glomerulonephritis. Based on this knowledge, this study aimed to define the effects of the TLR3 ligand polyriboinosinic:polyribocytidylic acid (poly(I:C)) on the expression of adhesion molecules and macrophage colony-stimulating factor (M-CSF) on resident glomerular cells. Experiments in MCs demonstrated that the activation of viral receptors by poly(I:C) leads to a time- and dose-dependent induction of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and M-CSF at both the mRNA and protein levels; these results were confirmed by incubating MCs with HCV RNA. As shown in knockdown experiments, this effect is specifically mediated by TLR3. The prestimulation of MCs with proinflammatory cytokines increases the effects of poly(I:C), except for its induction of VCAM-1. Tumor-necrosis factor (TNF)-α, likewise, induces ICAM-1, VCAM-1 and M-CSF, and amplifies the mesangial response to poly(I:C). These results were confirmed by incubating MCs with HCV RNA. We thus provide evidence that human MCs represent a potential target of the leukocytes and monocytes that infiltrate the glomerulus in viral disease-associated GN, highlighting the possibility that MCs may act as resident antigen-presenting cells.

Hepatitis C virus infection and kidney disease: a meta-analysis

BACKGROUND AND OBJECTIVES

Hepatitis C virus (HCV) infection and kidney disease are both highly prevalent diseases. The association between HCV and GN has been supported by previous research but little is known about the relationship between HCV and kidney disease.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A systematic review of the published medical literature was conducted to determine if HCV is associated with increased likelihood of kidney disease in the general population. A random-effects model was used to generate a summary estimate of the relative risk for kidney disease, defined as an estimated GFR <60 ml/min per 1.73 m(2) or proteinuria, with HCV across the published studies.

RESULTS

Nine clinical studies (817,917 unique individuals) were identified. Pooling of study results demonstrated the absence of a relationship between HCV seropositive status and reduced estimated GFR (adjusted relative risk, 1.12; 95% confidence interval, 0.91, 1.38; P=0.28) according to the random-effects model. HCV seropositive serology was an independent and significant risk factor for proteinuria (defined by urine dipstick test or spot urine albumin/creatinine ratio) in the general population, with a summary estimate for adjusted relative risk of 1.47 (95% confidence interval, 1.12, 1.94; P=0.006). Significant heterogeneity was observed between studies (Ri=0.82; P value by Q test, <0.001).

CONCLUSIONS

This meta-analysis shows that HCV is independently associated with proteinuria but not with reduced GFR in the general population. Substantial heterogeneity occurred.

Clinical features of patients with type 2 diabetes mellitus and hepatitis C infection

The objective of the present cross-sectional study was to assess the prevalence and the clinical and laboratory features of hepatitis C virus (HCV)-positive patients with type 2 diabetes mellitus (DM) attending either an outpatient clinic or hemodialysis units. Serologic-HCV testing was performed in 489 type 2 DM patients (303 outpatients and 186 on dialysis). A structured assessment of clinical, laboratory and DM-related complications was performed and the patients were then compared according to HCV infection status. Mean patient age was 60 years; HCV positivity (HCV+) was observed in 39 of 303 (12.9%) outpatients and in 34 of 186 (18.7%) dialysis patients. Among HCV+ patients, 32 were men (43.8%). HCV+ patients had higher serum levels of aspartate aminotransferase (0.90 ± 0.83 vs 0.35 ± 0.13 μKat/L), alanine aminotransferase (0.88 ± 0.93 vs 0.38 ± 0.19 μKat/L), gamma-glutamyl transferase (1.57 ± 2.52 vs 0.62 ± 0.87 μKat/L; P < 0.001), and serum iron (17.65 ± 6.68 vs 14.96 ± 4.72 μM; P = 0.011), and lower leukocyte and platelet counts (P = 0.010 and P < 0.001, respectively) than HCV-negative (HCV-) patients. HCV+ dialysis patients had higher diastolic blood pressure than HCV- patients (87.5 ± 6.7 vs 81.5 ± 6.0 mmHg; P = 0.005) and a lower prevalence of diabetic retinopathy (75 vs 92.7%; P = 0.007). In conclusion, our study showed that HCV is common among subjects with type 2 DM but is not associated with a higher prevalence of chronic diabetic complications.

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.

Hepatitis C increases the risk of progression of chronic kidney disease in patients with glomerulonephritis

BACKGROUND/AIMS

We have shown that hepatitis C does not increase the risk of developing chronic kidney disease (CKD), but it is not known if hepatitis C worsens progression of existing CKD.

METHODS

We retrospectively identified patients with primary glomerulonephritis on biopsy over 4 years, evaluating the progression of CKD over time.

RESULTS

The cohort consisted of 111 patients: 21% were positive for hepatitis C, 61% were negative for hepatitis C and 18% were not tested. The hepatitis C-positive subjects were more likely to be African American (p = 0.031), followed for fewer days (p = 0.007) and have diabetes and focal segmental glomerulosclerosis on biopsy (p < 0.001). Longitudinal follow-up of CKD progression using multiple creatinine measures analyzed by repeated measures ANCOVA demonstrated that patients with hepatitis C had a worsening creatinine over time compared to the hepatitis C-negative and not tested groups (p < 0.001). By Cox hazards regression analyses, risk of death/end-stage renal disease (ESRD) was decreased in patients who tested negative for hepatitis C compared to testing positive (0.46, CI 0.27-0.88), but this became nonsignificant after adjustment for mean arterial pressure and hemoglobin.

CONCLUSION

Our results support that infection with hepatitis C in patients with glomerulonephritis is associated with an increased risk of progression of CKD. Prospective studies are required to confirm these observations.

Association of hepatitis C and B virus infection with CKD in an endemic area in Taiwan: a cross-sectional study

BACKGROUND

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections may lead to nephropathy. However, the association between different types of viral hepatitis and chronic kidney disease (CKD) is not well established.

STUDY DESIGN

Cross-sectional study.

SETTING & PARTICIPANTS

A large-scale community study with 54,966 adults in a Taiwanese county endemic for HBV and HCV infection.

PREDICTOR

HCV infection alone, HBV infection alone, HBV/HCV coinfection, and neither.

OUTCOMES

Proteinuria (urine protein, >or=1+), low (<60 mL/min/1.73 m(2)) estimated glomerular filtration rate (eGFR), and CKD (proteinuria or eGFR <60 mL/min/1.73 m(2)).

MEASUREMENTS

HBV and HCV infection were defined as a seropositive test result for hepatitis B surface antigen and HCV antibody. Proteinuria was assessed using a repeated dipstick method. eGFR was computed using the 4-variable Modification of Diet in Renal Disease (MDRD) Study equation.

RESULTS

Mean age of the study group was 60.8 years. Prevalences of HCV infection alone, HBV infection alone, HBV/HCV coinfection, and neither were 9.4%, 9.9%, 0.9%, and 79.8%, respectively. 2,994 (5.4%), 7,936 (14.5%), and 9,602 (17.5%) participants had proteinuria, low eGFR, and CKD, respectively. Multivariate logistic regression analyses showed that HCV infection alone (OR, 1.26; 95% CI, 1.17-1.38), but not HBV infection alone (OR, 1.04; 95% CI, 0.96-1.14) or HBV/HCV coinfection (OR, 1.12; 95% CI, 0.87-1.45), was an independent risk factor for CKD. The prevalence of HCV seropositivity was higher in later CKD stages, changing from 8.5% in CKD stage 1 to 14.5% in CKD stages 4-5. Adjusted ORs for HCV infection alone were 1.14 (95% CI, 1.003-1.300) for proteinuria and 1.30 (95% CI, 1.20-1.42) for low eGFR.

LIMITATIONS

The definition of CKD status requires a 3-month duration of low eGFR or kidney damage; this was presumed, not documented, in this study.

CONCLUSIONS

HCV infection, but not HBV infection, was associated significantly with prevalence and disease severity of CKD in this HBV and HCV endemic area.

Standardized prevalence ratios for chronic hepatitis C virus infection among adult Japanese hemodialysis patients

Background

Many studies have estimated the prevalence of anti-hepatitis C virus (HCV) antibody among hemodialysis (HD) patients; however, the prevalence of HCV core antigen—which indicates the presence of chronic HCV infection—is not known.

Methods

Standardized prevalence ratios (SPRs) for anti-HCV antibody and HCV core antigen among HD patients (n = 1214) were calculated on the basis of data from the general population (n = 22 472) living in the same area.

Results

The prevalences of anti-HCV antibody and HCV core antigen were 12.5% and 7.8%, respectively, in male hemodialysis patients, and 8.5% and 4.1% in female hemodialysis patients. The SPRs (95% confidence interval) for anti-HCV antibody and HCV core antigen were 8.39 (6.72–10.1) and 12.9 (9.66–16.1), respectively, in males, and 5.42 (3.67–7.17) and 8.77 (4.72–12.8) in females.

Conclusions

The prevalences of chronic HCV infection among male and female HD patients were 13-fold and 9-fold, respectively, those of the population-based controls. Further studies should therefore be conducted to determine the extent of chronic HCV infection among HD patients in other populations and to determine whether chronic HCV infection contributes to increased mortality in HD patients.

Hepatitis C seropositivity and kidney function decline among women with HIV: data from the Women's Interagency HIV Study

BACKGROUND

How coinfection with hepatitis C virus (HCV) impacts on the trajectory of kidney function in human immunodeficiency virus (HIV)-infected patients is unclear. This study examined the effect of HCV infection on kidney function over time in women infected with HIV.

STUDY DESIGN

Retrospective observational cohort.

SETTING & PARTICIPANTS

Study sample included participants from the Women's Interagency HIV Study who were HIV infected and had undergone HCV antibody testing and serum creatinine measurement at baseline.

PREDICTOR

HCV seropositivity.

OUTCOMES & MEASUREMENT

Estimated glomerular filtration rate (eGFR) calculated from semi-annual serum creatinine measurements using the 4-variable Modification of Diet in Renal Diseases (MDRD) Study equation. Linear mixed models were used to evaluate the independent effect of HCV seropositivity on eGFR over time, adjusting for demographic factors, comorbid conditions, illicit drug use, measures of HIV disease status, use of medications, and interactions with baseline low eGFR (<60 mL/min/1.73 m(2)).

RESULTS

Of 2,684 HIV-infected women, 952 (35%) were found to be HCV seropositive. In 180 women with chronic kidney disease (CKD) at baseline (eGFR < 60 mL/min/1.73 m(2)), HCV seropositivity was independently associated with a fully adjusted net decrease in eGFR of approximately 5% per year (95% confidence interval, 3.2 to 7.2) relative to women who were seronegative. In contrast, HCV infection was not independently associated with a decrease in eGFR in women without low eGFR at baseline (P < 0.001 for interaction).

LIMITATIONS

The MDRD Study equation has not been validated as a measure of GFR in persons with HIV or HCV infection. Proteinuria was not included in the study analysis. Because the study is observational, effects of residual confounding cannot be excluded.

CONCLUSIONS

In HIV-infected women with CKD, coinfection with HCV is associated with a modest, but statistically significant, decrease in eGFR over time. More careful monitoring of kidney function may be warranted for HIV-infected patients with CKD who are also coinfected with HCV.

HCV response in patients with end stage renal disease treated with combination pegylated interferon alpha-2a and ribavirin

GOALS

To determine the efficacy and safety of combination therapy in patients with hepatitis C virus (HCV) and end-stage renal disease (ESRD).

BACKGROUND

There is little data on the treatment of ESRD patients with pegylated interferon and ribavirin. We designed a pilot study to determine the initial and 12-week posttreatment viral response.

STUDY

A nonrandomized, prospective observational study of adjusted-dose combination therapy. Twenty patients were enrolled and began pegylated interferon at 135 microg/wk SC, and 4 weeks later ribavirin was started at 200 mg PO weekly, increasing gradually to 3 times a week for a total of 48 weeks.

RESULTS

Twenty patients: M:F 18:2; mean age 52.4 years; genotype 1: 18, non-genotype 1: 2. Of the 20 patients, 5 withdrew before starting treatment. Of the 11 patients who reached 3 months, 6 had early virologic response, defined as at least a 2-log drop in their HCV count (54.5%). Of the 5 patients who were treated for 1-year, only 1 patient had a response 12 weeks after treatment. Side effects included 4 cases of anemia and 1 patient with headache.

CONCLUSIONS

The initial response rate in individuals taking 3 months of treatment in our study is comparable with studies in non-ESRD patients with no serious adverse side effects. However, the sustained posttreatment rate was low. This demonstrates that combination therapy is a safe therapeutic option in the ESRD population with HCV infection which needs further testing to determine if increasing the length of treatment and/or the dose of ribavirin will affect posttreatment rates.

Diabetic nephropathy--what are the unmet needs?

In this pandemic of diabetes and obesity, Asia will have the highest number of affected people with the greatest increase in the young-to-middle aged group. Asian patients have increased risk for diabetic kidney disease which may be compounded by low grade infection, obesity and genetic factors. In these subjects, the onset of albuminuria and diabetic kidney disease causes further perturbation of metabolic milieu with increased oxidative stress, anaemia and vascular calcification which interact to markedly increase the risk of cardiovascular disease. Despite receiving optimal care to control blood pressure and metabolic risk factors as well as inhibition of the renin-angiotensin system in a clinical trial setting, there is a considerable residual risk for cardio-renal complications in patients with diabetic kidney disease. Control of obesity and low grade inflammation as well as correction of anaemia may represent areas where novel strategies can be developed and tested to curb this rising global burden of cardio-renal complications.

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.