Hepatitis C virus associated glomerulopathies

Burden, Outcome, and Comorbidities of Extrahepatic Manifestations in Hepatitis B Virus Infections

Hepatitis B virus (HBV) infections affect approximately 296 million people around the world, and the prevalence of any past or present HBV infection during the years 2015-2018 was as high as 4.3%. Acute HBV infection often presents with nonspecific symptoms and is usually self-limited, but 5% of patients can have persistent infections leading to chronic HBV infection and the risk of turning into chronic HBV infection is significantly higher in babies with vertical transmission (95%). Patients with chronic HBV infection are usually asymptomatic, but 15 to 40% of chronic HBV carriers develop cirrhosis and/or hepatocellular carcinoma. In addition to liver-related disorders, HBV is also associated with several extrahepatic complications, including glomerulonephritis, cryoglobulinemia, neurologic disorders, psychological manifestations, polyarthritis, and dermatologic disorders. Making the diagnosis of HBV can be challenging since patients with chronic infections can remain symptom-free for decades before developing cirrhosis or hepatocellular carcinoma, and patients with acute HBV infection may have only mild, nonspecific symptoms. Therefore, understanding how this virus causes extrahepatic complications can help clinicians consider this possibility in patients with diverse symptom presentations. The pathophysiology of these extrahepatic disorders likely involves immune-related tissue injury following immune complex formation and inflammatory cascades. In some cases, direct viral infection of extrahepatic tissue may cause a clinical syndrome. Currently, the American Association for the Study of Liver Diseases recommends treatment of chronic HBV infections with interferon therapy and/or nucleos(t)ide analogs, and this treatment has been reported to improve some extrahepatic disorders in some patients with chronic HBV infection. These extrahepatic complications have a significant role in disease outcomes and increase medical costs, morbidity, and mortality. Therefore, understanding the frequency and pathogenesis of these extrahepatic complications provides important information for both specialists and nonspecialists and may help clinicians identify patients at an earlier stage of their infection.

IFN-γ, IL-17, IL-22+ CD4+ subset in patients with hepatitis C virus and correlation with clinical factor

BACKGROUND

CD4+ T cell responses in HCV infection have a crucial role in the immunopathology of hepatitis C virus (HCV) infection. Our aim was to investigate the frequency of Th1, Th17, and Th22 cells in HCV-infected patients and elucidate their role in the progression of the disease.

METHODS

Twenty-six HCV-infected patients and 26 healthy individuals were recruited. Peripheral blood mononuclear cells (PBMCs) were stained to separate CD4, IFN-γ, IL-17, and IL-22 producing cells using flow cytometry.

RESULTS

Results showed that the mean expression of IL-22 in CD4+ T cells was significantly lower in HCV-infected patients compared to healthy controls. About correlation with clinical factor and T subsets, a negative correlation between the frequency of CD4+ IFN-γ+ cells and Thyroxine level (T4) was observed in the patients. The data showed a positive link between thyroid-stimulating hormone (TSH), cholesterol levels, and the frequency of Th17 cells. In addition, a positive correlation was seen between serum creatinine level with both Th1 and Th17. Ultimately, it was found that there was a positive link between viral burden and IL-17+ IL-22+ cells and a negative correlation between viral load and pure Th22.

CONCLUSIONS

Our findings indicate that Th22 cells may play a part in the immunopathology of HCV and show the associations between Thelper subsets and the clinical signs of the disease.

Cryoglobulinemic vasculitis: a 2023 update

PURPOSE OF REVIEW

Cryoglobulinemic vasculitis (CV) is an immune complex mediated small vessel vasculitis characterized by the presence of cryoglobulins in serum, often associated with hepatitis C infection, systemic autoimmune diseases or hematological conditions. The focus of this review is to provide an update on new insights into pathogenesis, epidemiology and therapies of infectious and noninfectious type II and type III CV.

RECENT FINDINGS

The introduction of new antiviral drugs for treatment of hepatitis C infection implied major changes in HCV-related CV, allowing to shed new lights on CV pathogenesis and mechanisms of relapse and, therefore, to increase the relevance of autoimmune diseases in CV epidemiology. Specific B-cell clones are involved in the production of pathogenic immune complexes that leads to small-vessel vasculitis. Therefore, both antiviral treatments [direct-acting antivirals (DAAs) and oral nucleot(s)ide analogues] and targeted anti-CD20 therapies (rituximab) prove to be safe and effective options, leading to a better prognosis. Association of Sjögren syndrome and CV defines a specific phenotype of patients, characterized by severe manifestations and poor outcome.

SUMMARY

Removing viral stimulation on B-cells through direct-acting antivirals and blocking B-cells proliferation and differentiation with rituximab are the goals of treatment of CV. However, further research is needed to identify prognostic factors of refractory and relapsing disease.

New-Onset Acute Interstitial Nephritis Post-SARS-CoV-2 Infection and COVID-19 Vaccination: A Panoramic Review

The 2019 coronavirus disease (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has posed a considerable challenge to global healthcare. Acute interstitial nephritis (AIN) post SARS-CoV-2 infection and vaccination has been reported, but its clinical features and pathogenesis remained unclear. We reviewed so far the largest 22 cases of AIN post SARS-CoV-2 infection and 36 cases of AIN following COVID-19 vaccination. The onset of AIN was mainly related to messenger RNA vaccines (52.8%). Apart from fever, proteinuria (45.5%) was the main manifestation of AIN post SARS-CoV-2 infection, left acute kidney injury (AKI, 63.9%) in patients post COVID-19 vaccination. The potential mechanism of vaccination induced AIN was conjugating vaccines with proteins to form a hapten, which activated dendritic cells and promoted a cascade immunological reaction leading to AIN.

Assessment of factors affecting response of direct-acting antivirals in chronic hepatitis C patients

Background

Hepatitis C virus (HCV) is a universally prevalent pathogen and a major cause of liver-related morbidity and mortality worldwide. The evolution of antiviral therapy for HCV has rapidly progressed from interferon (IFN)-based therapies to IFN-free combinations of direct-acting antivirals (DAAs).

Aims

This study aims to assess the response of DAAs in chronic hepatitis C (CHC) patients and to study the various factors affecting the response of DAAs in CHC.

Settings and Design

This longitudinal observational study spanning over a year was conducted in the Medicine department of a tertiary care teaching hospital.

Materials and Methods

The study was conducted on 400 adult CHC patients, diagnosed by a positive anti-HCV antibody test and a detectable viral load (HCV RNA) by real time polymerase chain reaction (RT-PCR), registered for treatment with DAAs. The first 400 patients satisfying the eligibility criteria were enrolled by non-probability consecutive sampling. All the participants were treated as per the National Viral Hepatitis Control Programme (NVHCP) guidelines. Repeat HCV viral load was done at or after 12 weeks of completion of anti-viral therapy to ascertain sustained virological response (SVR). Various factors which might predict treatment response were analyzed.

Statistical Analysis Used

The continuous variables were expressed as mean and standard deviation, while the categorical variables were summarized as frequencies and percentages. The Student's independent t-test was employed for the comparison of continuous variables. The Chi-square or Fisher's exact test, whichever is appropriate, was employed for the comparison of categorical variables. Multivariate Logistic Regression was used to identify the independent predictors of treatment nonresponse. A P < 0.05 was considered statistically significant.

Results

The mean age of the subjects was 42.3 ± 15.23 years with a male-to-female ratio of 1.96:1. Most of the patients (80.5%) were non-cirrhotic; among 19.5% cirrhotic, 13% were compensated while 6.5% were decompensated cirrhotic. The overall SVR done at or after 12 weeks of completion of treatment was 88.75%. Age, gender distribution, occupation, socioeconomic status, educational status, body mass index, treatment regimen, duration of treatment, and baseline viral load did not alter the treatment response. Among comorbidities, only diabetes mellitus (DM) and human immunodeficiency virus (HIV) co-infection adversely affected the treatment response (P = 0.009 and P < 0.001, respectively). Intravenous (IV) drug abuse was significantly associated with treatment failure (P < 0.001). The presence of liver cirrhosis (P < 0.001), thrombocytopenia (P < 0.001), elevated transaminases (alanine transaminase: P = 0.021, aspartate transaminase: P < 0.001), and previous treatment experience (P = 0.038) were other significant predictors of treatment failure.

Conclusions

DAAs are highly efficacious drugs in the treatment of CHC with a high rate of treatment response. Significant predictors of CHC treatment failure included comorbidities especially DM and HIV co-infection, IV drug abuse, presence of liver cirrhosis, thrombocytopenia, elevated transaminases, and previous treatment experience. However, independent predictors of treatment nonresponse observed in this study were thrombocytopenia, IV drug abuse, and liver cirrhosis.

Long-term follow-up of HCV-infected patients with end-stage chronic kidney disease after sustained virological response with direct-acting antiviral therapy

BACKGROUND AND AIM

Patients with chronic kidney disease (CKD) and hepatitis C infection can be safely and effectively treated with direct-acting antivirals (DAAs). However, there is scarce data on the long-term impact of hepatitis C cure on CKD. The aim of this study was to assess the long-term mortality, morbidity and hepatic/renal function outcomes in a cohort of HCV-infected individuals with CKD treated with DAAs.

METHODS

135 HCV patients with CKD stage 3b-5 who received ombitasvir/paritaprevir/ritonavir±dasabuvir in a multicenter study were evaluated for long-term hepatic and renal outcomes and their associated mortality.

RESULTS

125 patients achieved SVR and 66 were included. Prior to SVR, 53 were under renal replacement therapy (RRT) and 25 (37.8%) had liver cirrhosis. After a follow-up of 4.5 years, 25 (38%) required kidney transplantation but none combined liver-kidney. No changes in renal function were observed among the 51 patients who did not receive renal transplant although eGFR values improved in those with baseline CKD stage 3b-4. Three (5.6%) subjects were weaned from RRT. Eighteen (27.3%) patients died, mostly from cardiovascular events; 2 developed liver decompensation and 1 hepatocellular carcinoma. No HCV reinfection was observed.

CONCLUSIONS

Long-term mortality remained high among end-stage CKD patients despite HCV cure. Overall, no improvement in renal function was observed and a high proportion of patients required kidney transplantation. However, in CKD stage 3b-4 HCV cure may play a positive role in renal function.

Risk Factors for Hepatitis E Virus Infection and Eating Habits in Kidney Transplant Recipients

There is a significant risk for ongoing and treatment-resistant courses of hepatitis E virus (HEV) infection in patients after solid organ transplantation. The aim of this study was to identify risk factors for the development of hepatitis E, including the dietary habits of patients. We conducted a retrospective single-center study with 59 adult kidney and combined kidney transplant recipients who were diagnosed with HEV infection between 2013 and 2020. The outcomes of HEV infections were analyzed during a median follow-up of 4.3 years. Patients were compared with a control cohort of 251 transplant patients with elevated liver enzymes but without evidence of an HEV infection. Patients' alimentary exposures during the time before disease onset or diagnosis were assessed. Previous intense immunosuppression, especially treatment with high-dose steroids and rituximab, was a significant risk factor to acquire hepatitis E after solid organ transplantation. Only 11 out of 59 (18.6%) patients reached remission without further ribavirin (RBV) treatment. A total of 48 patients were treated with RBV, of which 19 patients (39.6%) had either viral rebounds after the end of treatment or did not reach viral clearance at all. Higher age (>60 years) and a BMI ≤ 20 kg/m² were risk factors for RBV treatment failure. Deterioration in kidney function with a drop in eGFR (p = 0.046) and a rise in proteinuria was more common in patients with persistent hepatitis E viremia. HEV infection was associated with the consumption of undercooked pork or pork products prior to infection. Patients also reported processing raw meat with bare hands at home more frequently than the controls. Overall, we showed that the intensity of immunosuppression, higher age, a low BMI and the consumption of undercooked pork meat correlated with the development of hepatitis E.

Long-term Evolution of Estimated Glomerular Filtration Rate in Patients With Antiviral Treatment for Hepatitis C Virus Infection

BACKGROUND & AIMS

Data regarding the long-term evolution of estimated glomerular filtration rate (eGFR) in patients receiving antiviral treatment for hepatitis C virus are limited.

METHODS

A total of 1987 patients with eGFR ≥15 mL/min/1.73m² who received interferon or direct-acting antiviral treatment were prospectively enrolled in this cohort study. The eGFR was assessed biannually by the Chronic Kidney Disease Epidemiology Collaboration equation from the time point of sustained virologic response (SVR₁₂). Multivariate generalized estimated equation was used to assess the association between the factors of interest and evolution of eGFR following antiviral treatment. Multivariate Cox regression analysis was used to assess the relative risk of end-stage renal disease (ESRD), defined as an eGFR <15 mL/min/1.73m².

RESULTS

Patients who achieved SVR₁₂ (adjusted slope coefficient difference: 2.36 mL/min/1.73 m²/year; 95% confidence interval [CI], 1.50 to 3.32; P < .001) were associated with eGFR improvement, compared with those who did not achieve SVR₁₂. Among patients who achieved SVR₁₂, the eGFR evolution was comparable (adjusted slope coefficient difference: 0.31 mL/min/1.73m²/year; 95% CI, -0.34 to 0.96; P = .35) in those treated with interferon or direct-acting antiviral. The incidence rates of ESRD in patients who achieved and did not achieve SVR₁₂ were 0.06 per 100 person-years and 0.37 per 100 person-years. Patients who achieved SVR₁₂ were associated with a lower risk of ESRD (adjusted hazard ratio, 0.24; 95% CI, 0.05-0.68; P = .021).

CONCLUSIONS

The long-term eGFR evolution and risk of ESRD are significantly improved in patients who achieve SVR₁₂ with anti- hepatitis C virus treatment.

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.

Hepatitis Virus C-associated Nephropathy: A Review and Update

Hepatitis C virus (HCV) infection causes hepatic and extrahepatic organ involvement. Chronic kidney disease (CKD) is a prevalent non-communicable disorder, accounting for significant morbidity and mortality worldwide. Acute kidney injury and CKD are not uncommon sequels of acute or chronic HCV infection.

The pathogenesis of HCV-associated kidney injuries is not well explored. Excess cryoglobulin production occurs in HCV infection. The cryoglobulin may initiate immune complex-mediated vasculitis, inducing vascular thrombosis and inflammation due to cryoglobulin deposits.

Furthermore, direct damage to nephron parts also occurs in HCV patients. Other contributory causes such as hypertension, diabetes, and genetic polymorphism enhance the risk of kidney damage in HCV-infected individuals. Implementing CKD prevention, regular evaluation, and therapy may improve the HCV burden of kidney damage and its related outcomes.

Therefore, in this review, we discuss and update the possible mechanism(s) of kidney injury pathogenesis with HCV infection. We searched for related published articles in EMBASE, Google Scholar, Google, PubMed, and Scopus. We used various texts and phrases, including hepatitis virus and kidney, HCV and CKD, kidney pathology in viral hepatitis, kidney transplantation in HCV-infected patients, kidney allograft survival in viral hepatitis patients, mechanism of kidney pathology in viral hepatitis, dialysis and viral hepatitis, HCV infection and kidney injuries, and viral hepatitis and CKD progression, etc. to identify relevant articles.

Pan-genotypic direct-acting antivirals for patients with hepatitis C virus infection and chronic kidney disease stage 4 or 5

Hepatitis C virus (HCV) infection is a major health problem with significant clinical and economic burdens in patients with chronic kidney disease (CKD) stage 4 or 5. Current guidelines recommend pan-genotypic direct-acting antivirals (DAAs) to be the first-line treatment of choice for HCV. This review summarizes the updated knowledge regarding the epidemiology, natural history, public health perspectives of HCV in patients with CKD stage 4 or 5, including those on maintenance dialysis, and the performance of pan-genotypic DAAs in these patients. The prevalence and incidence of HCV are much higher in patients with CKD stage 4 or 5 than in the general population. The prognosis is compromised if HCV patients are left untreated regardless of kidney transplantation (KT). Following treatment-induced HCV eradication, patient can improve the health-related outcomes by maintaining a long-term aviremic state. The sustained virologic response (SVR₁₂) rates and safety profiles of pan-genotypic DAAs against HCV are excellent irrespective of KT. No dose adjustment of pan-genotypic DAAs is required across CKD stages. Assessing drug–drug interactions (DDIs) before HCV treatment is vital to secure on-treatment safety. The use of prophylactic or preemptive pan-genotypic DAAs in HCV-negative recipients who receive HCV-positive kidneys has shown promise in shortening KT waiting time, achieving excellent on-treatment efficacy and safety, and maintaining post-KT patient and graft survival. HCV elimination is highly feasible through multifaceted interventions, including mass screening, treatment scale-up, universal precautions, and post-SVR₁₂ reinfection surveillance.

Revolution in the diagnosis and management of hepatitis C virus infection in current era

Chronic hepatitis C virus (HCV) infection is a major global public health problem, particularly in developing part of the world. Significant advances have been made in the early diagnosis and treatment of the disease. Its management has been particularly revolutionized during the past two decades. In this review, we summarize the major advances in the diagnostic and management armamentarium for chronic HCV infection. The focus of the present review is on the newer directly acting anti-viral agents, which have revolutionized the management of chronic HCV infection. Management of uncomplicated chronic HCV infection and of specific complications and special at-risk populations of patients will be covered in detail. Despite the advent and approval of highly effective and well tolerable oral agents, still many challenges remain, particularly the affordability, the equitable distribution and access to later drugs. The World Health Organization aims to eliminate viral hepatitis including HCV by 2030 since its poses a major public health threat. There is an urgent need to ensure uniform and early access to diagnostic and therapeutic facilities throughout the world if the later goal has to be realized.

Renal manifestations of hepatitis E among immunocompetent and solid organ transplant recipients

Hepatitis E virus (HEV) infections are generally self-limited. Rare cases of hepatitis E induced fulminant liver failure requiring liver transplantation are reported in the literature. Even though HEV infection is generally encountered among developing countries, a recent uptrend is reported in developed countries. Consumption of unprocessed meat and zoonosis are considered to be the likely transmission modalities in developed countries. Renal involvement of HEV generally holds a benign and self-limited course. Although rare cases of cryoglobulinemia are reported in immunocompetent patients, glomerular manifestations of HEV infection are frequently encountered in immunocompromised and solid organ transplant recipients. The spectrum of renal manifestations of HEV infection include pre-renal failure, glomerular disorders, tubular and interstitial injury. Kidney biopsy is the gold standard diagnostic test that confirms the pattern of injury. Management predominantly includes conservative approach. Reduction of immunosuppressive medications and ribavirin (for 3-6 mo) is considered among patients with solid organ transplants. Here we review the clinical course, pathogenesis, renal manifestations, and management of HEV among immunocompetent and solid organ transplant recipients.

Chronic Kidney Disease from Polyvinylpyrrolidone Deposition in Persons with Intravenous Drug Use

BACKGROUND AND OBJECTIVES

Persons with intravenous drug use have a higher risk of developing CKD compared with the general population. In Norway, deposits of polyvinylpyrrolidone have been observed in kidney biopsies taken from persons with opioid addiction and intravenous drug use since 2009. Polyvinylpyrrolidone is an excipient commonly used in pharmaceuticals, and the polyvinylpyrrolidone deposits observed in these patients were caused by intravenous injection of a specific oral methadone syrup containing very high molecular weight polyvinylpyrrolidone. Here, we present the clinicopathologic findings from 28 patients with CKD associated with polyvinylpyrrolidone deposition in the kidney.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The 28 patients and their kidney biopsies were included when polyvinylpyrrolidone deposition was recognized, either retrospectively or at the time of diagnostic evaluation. Biopsies were taken between 2009 and 2016. We collected laboratory parameters and clinical data from digital patient charts. For each kidney biopsy, the glomerular volume, extent of polyvinylpyrrolidone deposition, and tubulointerstitial area with tubular atrophy were assessed quantitatively.

RESULTS

All patients (mean age: 37 years) had CKD (mean eGFR: 33 ml/min per 1.73 m²) and normal urine protein or non-nephrotic-range proteinuria. Biopsies showed moderate to severe tubular atrophy (mean extent: 65%) and interstitial infiltrates of vacuolated macrophages containing polyvinylpyrrolidone (mean share of biopsy area: 1.5%). Underperfused and ischemic glomeruli were common findings. In 22 samples, ultrastructural investigation revealed polyvinylpyrrolidone-containing vacuoles in the mesangial or endothelial cells of glomeruli. At the last follow-up, most patients had stable or improved eGFR. Two patients had developed kidney failure and underwent hemodialysis.

CONCLUSIONS

Intravenous injection of a specific oral methadone syrup caused polyvinylpyrrolidone deposition in the kidney in persons with opioid addiction and intravenous drug use. Kidney biopsy findings suggested an association between polyvinylpyrrolidone deposition and tubular atrophy.

The nature and prognosis of renal diseases in chronic hepatitis-C-infected diabetic Egyptian patients: The role of renal biopsy

BACKGROUND AND AIMS

Egypt has a wide prevalence of Diabetes and chronic HCV infection. The relationship between diabetes and HCV is bidirectional and both have their impact on kidney. The aim is to study the exact diagnostic and prognostic significance of renal biopsy in Diabetic HCV-infected patients with renal disease.

MATERIAL AND METHODS

In this cross-sectional study, we compared the clinical and histopathological characteristics of sixty-five patients all of them presented with evidence of kidney injury. The main study group included twenty patients who had DM and hepatitis c virus (DM-HCV); the other two groups were included as diseased control, twenty hepatitis c virus (HCV) patients, and twenty-five diabetic non-HCV patients (DM).

RESULTS

DM-HCV patients had a statistically significantly higher percentage of sclerosed glomeruli (Median Value of 44.5% versus 7% in DM and 7% in HCV). The tendency toward diffuse (20%) and global (75%) patterns of sclerosis as well as moderate to severe tubular atrophy (45%), moderate to severe interstitial fibrosis (55%) were reported in the DM-HCV group. Electron microscopic showed a significantly higher frequency of podocytopathies (70% in DM-HCV versus 12% in DM).

CONCLUSION

These results confirmed the diagnostic and prognostic significance of histopathological evaluation in guiding the management plan which cannot be replaced by just relying on clinical prediction.

A Review on Extrahepatic Manifestations of Chronic Hepatitis C Virus Infection and the Impact of Direct-Acting Antiviral Therapy

Extrahepatic manifestations are a feature of chronic hepatitis C virus (HCV) infection. In the course of chronic HCV infection, about 70% of patients have one or more extrahepatic manifestations. The latter are often the first and only clinical sign of infection. Experimental and clinical data support a causal association for many extrahepatic manifestations and HCV infection, which include mixed cryoglobulinemia, non-Hodgkin lymphomas (NHL), cardiovascular disease, insulin resistance, type 2 diabetes, neurological and psychiatric disease and other rheumatic diseases. All these extrahepatic conditions influence the morbidity, quality of life and mortality of HCV-infected patients. Currently, interferon-free therapeutic regimens with direct-acting antiviral agents (DAA) offer the possibility of treatment to almost the entire infected population, irrespective of stage of cirrhosis and associated serious comorbidities, always maintaining a high efficacy and tolerability. Several studies have shown a close association between HCV clearance by DAAs and an improvement or reduction in the risk of extrahepatic manifestations. Patients with HCV after a sustained virologic response (SVR) by DAA treatment have a lower risk than non-responders of developing cryoglobulinemic vasculitis and B-cell non-Hodgkin’s lymphomas. Furthermore, the SVR by DAA also reduces the risk of acute coronary syndrome, cardiovascular disease, insulin resistance and type 2 diabetes, and it improves atherosclerosis. HCV clearance by DAA also improves the quality of life and survival of patients with chronic HCV infection with associated extrahepatic diseases. Thus, DAAs should be initiated as early as possible in HCV patients with extrahepatic manifestations.

Identification of Key Regulators of Hepatitis C Virus-Induced Hepatocellular Carcinoma by Integrating Whole-Genome and Transcriptome Sequencing Data

Background: Hepatitis C virus (HCV) infection is a major cause of cirrhosis and hepatocellular carcinoma (HCC). Despite recent advances in the understanding of the biological basis of HCC development, the molecular mechanisms underlying HCV-induced HCC (HCC-HCV) remain unclear. The carcinogenic potential of HCV varies according to the genotype and mutation in its viral sequence. Moreover, regulatory pathways play important roles in many pathogenic processes. Therefore, identifying the pathways by which HCV induces HCC may enable improved HCC diagnosis and treatment.

Methods: We employed a systematic approach to identify an important regulatory module in the process of HCV-HCC development to find the important regulators. First, an HCV-related HCC subnetwork was constructed based on the gene expression in HCC-HCV patients and HCC patients. A priority algorithm was then used to extract the module from the subnetworks, and all the regulatory relationships of the core genes of the network were extracted. Integrating the significantly highly mutated genes involved in the HCC-HCV patients, core regulatory modules and key regulators related to disease prognosis and progression were identified.

Result: The key regulatory genes including EXO1, VCAN, KIT, and hsa-miR-200c-5p were found to play vital roles in HCV-HCC development. Based on the statistics analysis, EXO1, VCAN, and KIT mutations are potential biomarkers for HCV–HCC prognosis at the genomic level, whereas has-miR-200c-5P is a potential biomarker for HCV–HCC prognosis at the expression level.

Conclusion: We identified three significantly mutated genes and one differentially expressed miRNA, all related to HCC prognosis. As potential pathogenic factors of HCC, these genes and the miRNA could be new biomarkers for HCV-HCC diagnosis.

Hepatitis C-associated focal proliferative glomerulonephritis in an aviremic recipient of a hepatitis C-positive antibody donor liver

Shortage of organs for liver transplantation (LT) and the availability of highly efficient pan-genotypic direct-acting antivirals (DAAs) against hepatitis C virus (HCV) have allowed the use of livers from HCV-positive antibody/negative nucleic acid test donors (dHCV Ab+/NAT-) into aviremic HCV recipients over the last few years. We report the case of a patient who received an LT from an HCV Ab+/NAT- donor and, after HCV viremic conversion, developed a nephrotic syndrome due to a focal proliferative glomerulonephritis early after LT. Patient's renal function and proteinuria resolved after successful treatment with DAAs. Renal and hepatic function remain normal over 24 months of follow-up. This case restates the success of LT using livers from dHCV Ab+/NAT- in aviremic recipients in the context of DAAs while illustrating the risk for potential complications associated with the HCV transmission and reinforcing the importance of early initiation of anti-HCV therapy.

Changes in clinical scenarios, management, and perspectives of patients with chronic hepatitis C after viral clearance by direct-acting antivirals

INTRODUCTION

Hepatitis C virus (HCV) causes a systemic infection inducing hepatic and extrahepatic diseases. These latter involve cardiovascular system, kidney, brain, endocrine, glucose, and lipid metabolism, and the immune system. HCV infection is associated with an increased risk of morbidity and mortality for both hepatic and extrahepatic events. Direct-acting antivirals (DAA), introduced in the most recent years for HCV treatment, are effective in up to 99% of cases and have changed the clinical scenarios and management of these patients.

AREAS COVERED

The literature on the impact of HCV clearance by DAA on both hepatic and extrahepatic disease outcomes has been analyzed and discussed in this review in order to summarize the full therapeutic potential and its weaknesses.

EXPERT OPINION

Patients achieving HCV clearance have improved hepatic and extrahepatic diseases, quality of life and survival. They have lower incidence of cardiovascular disease, type 2 diabetes, kidney damage, and immuno-mediated manifestations. However, the improvements are related to the degree of pre-treatment organ damage. Therefore, a significant percentage of patients with advanced disease remains at risk of morbidity and mortality and must be monitored in the post-treatment. In addition, data emphasize the importance of starting treatment during the early stages of HCV infection.

HCV Infection and Chronic Renal Disease

Chronic Hepatitis C virus (HCV) infection is defined as persistence of HCV RNA in the blood for more than six months. HCV is a major cause of chronic liver disease and cirrhosis. It’s serious public health problem, affects about 71 million people worldwide. HCV doesn’t destroy hepatocytes directly. It activates the host's innate and acquired immune system and causes liver injury indirectly. Behind hepatic, HCV can cause extra-hepatic manifestations. One of them is renal disease which can lead to end-stage renal disease, ESRD. The prevalence of HCV infection in patients on hemodialysis is high, ranging from 5% to 60%. HCV infection is a significant cause of morbidity and mortality in patients with ESRD on hemodialysis. In this review, we discuss HCV infection and chronic renal disease as comorbidities, their severity and outcome.

Dynamics of serum α-fetoprotein in viral hepatitis C without hepatocellular carcinoma

Viral hepatitis C represents a significant liver pathology worldwide, with a detrimental impact on national health systems. The present study aimed to correlate the levels of serum α-fetoprotein (AFP) with prognostic tools such as Fibroscan^®, the presence of mixed cryoglobulinemia, and various demographic and standard biochemical markers, in patients with chronic hepatitis C, unrelated to hepatocellular carcinoma (HCC). A clinical study was designed considering three study groups: Hepatitis C virus (HCV) group including 35 patients with chronic hepatitis C and detectible viral load; sustained viral response (SVR) group including 20 HCV patients without detectable virus load 12 weeks after therapy cessation; a control group represented by 37 healthy volunteers. It was observed that serum AFP was moderately increased in the HCV and SVR groups and was positively correlated with aspartate transaminase (AST), alkaline phosphatase (AP), and γ-glutamyl transferase (GGT). The incidence of mixed cryoglobulinemia was increased in the HCV group, and the degree of fibrosis assessed by Fibroscan^® was increased in both the HCV and SVR groups. In conclusion, the data revealed that a moderate increase in AFP levels could be present in patients with HCV even in the absence of HCC, unrelated to viral load or therapy response and that there was a linear positive correlation between serum levels of AFP and the degree of hepatic cytolysis and cholestasis. Additionally, mixed cryoglobulinemia was present in HCV patients with patent viral load, decreasing in those with SVR after therapy cessation unrelated to any renal impairment, while the degree of fibrosis was increased in HCV-infected patients, with no reversibility 12 weeks after successful therapy.

Tubular cell damage may be the earliest sign of renal extrahepatic manifestation caused by Hepatitis C

Chronic kidney disease (CKD) is one of the most well-known extrahepatic manifestations caused by hepatitis C infection (HCV). CKD is typically discovered at a late stage. HCV-nephropathy may show different histopathologic patterns, as both glomerular and tubulointerstitial damage have been described. Identification of patients with early renal manifestations would be beneficial to provide treatment and avoid progression to CKD. The observational prospective single-center HCVKID study assessed the prevalence of early renal manifestations in patients with chronic HCV and compared these patients with HCV-negative healthy controls cross-sectionally. HCV-positive patients with and without renal manifestations were also compared to define biomarkers suitable for identifying early manifestations in standard clinical practice. Tubular proteinuria as judged by urine α 1-microglobulin was the most common early renal manifestation found in 11% in HCV-positive patients, followed by hematuria in 8%. Kidney filtration was statistically significantly lower among HCV-positive patients with renal manifestation according to any calculation method. There were no significant differences in duration of infection or stage of liver fibrosis between patients with or without renal manifestations. Tubular cell damage may be the earliest sign of renal dysfunction caused by HCV. Complement activation also correlates with the dysfunction, indicating of contribution to HCV-induced renal manifestations even in their early phase.

Advances in the Management of Renal Dysfunction in Patients With Cirrhosis

Renal dysfunction frequently develops in patients with advanced liver disease. Renal dysfunction in this setting is associated with adverse outcomes and an unfavorable prognosis. Hepatorenal syndrome (HRS), defined as worsening renal function in patients with advanced cirrhosis that can present either acutely (<3 months) or more indolently in the absence of other etiologies, remains a common cause of acute kidney injury. If reversal is not promptly achieved, rapid decline to mortality is common. Volume expansion and vasoconstrictors are the mainstays of therapy. Terlipressin, a vasopressin analogue licensed in several countries but not in the United States, is currently used for the treatment of HRS. Timely liver transplantation remains the only effective therapeutic option for a large group of patients with persistent renal dysfunction despite pharmacotherapy. In patients with underlying chronic renal dysfunction, simultaneous liver-kidney transplantation should be considered. The aim of this article is to present an overview of renal dysfunction in patients with cirrhosis, including diagnosis and management.

[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.

Hepatitis C virus (HCV) diagnosis via microfluidics

Humans are subjected to various diseases; hence, proper diagnosis helps avoid further disease consequences. One such severe issue that could cause significant damage to the human liver is the hepatitis C virus (HCV). Several techniques are available to detect HCV under various categories, such as detection through antibodies, antigens, and RNA. Although immunoassays play a significant role in discovering hepatitis viruses, there is a need for point-of-care tests (POCT). Some developing strategies are required to ensure the appropriate selection of POCT for HCV detection, initiate appropriate antiviral therapy, and define associated risks, which will be critical in achieving optimal outcomes. Though molecular assays are precise, reproducible, sensitive, and specific, alternative strategies are required to enhance HCV diagnosis among the infected population. Herein, we described and assessed the potential of various microfluidic detection techniques and confirmatory approaches used in present communities. In addition, current key market players in HCV chip-based diagnosis and the future perspectives on the basis of which the diagnosis can be made easier are presented in the present review.

Hepatitis C-related membranoproliferative glomerulonephritis in the era of direct antiviral agents

Membranoproliferative glomerulonephritis (MPGN) is the most typical Hepatitis C virus (HCV)-associated glomerulopathy, and the available data about the utilization of direct-acting antivirals (DAA) in HCV-associated glomerulonephritis is inadequate. We evaluated the renal and viral response in two cases of HCV-related MPGN; the first caused by cryoglobulinemia while the second was cryoglobulin-negative. Both patients received immunosuppression besides DAA in different regimens. They achieved partial remission but remained immunosuppression-dependent for more than 6 months after DAA despite sustained virological response, which enabled safer but incomplete immunosuppression withdrawal. Both patients were tested for occult HCV in peripheral blood mononuclear cells and found to be negative. Hence, the treatment of HCV-related MPGN ought to be according to the clinical condition and the effects of drug therapy. It is important to consider that renal response can lag behind the virological response.

HCV cirrhotic patients treated with direct-acting antivirals: Detection of tubular dysfunction and resolution after viral clearance

BACKGROUND/AIMS

Hepatitis C virus (HCV) has been identified in tubular epithelial cells of infected patients; however, the presence of tubular dysfunction, which is a risk factor for chronic kidney disease (CKD), has never been examined in vivo. The present prospective longitudinal study aimed to estimate the prevalence of tubular dysfunction alone or with glomerular damage and its evolution after HCV clearance in cirrhotic patients.

METHODS

One hundred and thirty-five consecutive Child-Pugh A cirrhotic patients were evaluated before antiviral treatment and 6 months after the end of therapy. Tubular dysfunction was evaluated by urinary alpha1-microglobulin to creatinine ratio (α1-MCR), and glomerular damage was assessed by urinary albumin to creatinine ratio (ACR).

RESULTS

Almost all the patients (93.3%) showed a normal or mildly decreased e-GFR (KDIGO-G1/G2-categories). Tubular dysfunction was found in 23.7% (32/135) of patients, co-occurring with glomerular damage in 37.5% (12/32) of cases, while glomerular damage was found in 16.3% (22/135) of patients. In multiple logistic regression, glomerular damage and the concomitant presence of diabetes and hypertension were the only predictors significantly associated with tubular dysfunction. After HCV clearance, patients experienced a significant reduction of α1-MCR levels (21.0 vs 10.5 μg/mg, P = .009) and tubular dysfunction resolved in 57.1% of subjects.

CONCLUSIONS

Tubular dysfunction is an unrecognized feature of HCV-related kidney disease in cirrhotic patients and its presence should be primarily investigated in subjects with glomerular damage, diabetes and hypertension, despite normal e-GFR. Tubular dysfunction resolves in the majority of cases after HCV clearance; however, it may persist after antiviral treatment and further studies should evaluate its long-term impact on kidney function.

Potential role of ACE2-related microRNAs in COVID-19-associated nephropathy

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for coronavirus disease (COVID-19), potentially have severe kidney adverse effects. This organ expressed angiotensin-converting enzyme 2 (ACE2), the transmembrane protein which facilitate the entering of the virus into the cell. Therefore, early detection of the kidney manifestations of COVID-19 is crucial. Previous studies showed ACE2 role in various indications of this disease, especially in kidney effects. The MicroRNAs (miRNAs) in this organ affected ACE2 expression. Therefore, this review aims at summarizing the literature of a novel miRNA-based therapy and its potential applications in COVID-19-associated nephropathy. Furthermore, previous studies were analyzed for the kidney manifestations of COVID-19 and the miRNAs role that were published on the online databases, namely MEDLINE (PubMed) and Scopus. Several miRNAs, particularly miR-18 (which was upregulated in nephropathy), played a crucial role in ACE2 expression. Therefore, the antimiR-18 roles were summarized in various primate models that aided in developing the therapy for ACE2 related diseases.

Hepatitis C virus-related cryoglobulinemic vasculitis

INTRODUCTION

Hepatitis C virus (HCV) infection affects about 170 million people worldwide. HCV is responsible for both hepatitis and extra-hepatic manifestations. Chronic infection has been shown to develop in about 70% of cases, and it can progress to cirrhosis or hepatocellular carcinoma. Ten percent of HCV patients may develop extra-hepatic manifestations, including mixed cryoglobulinemia (MC) and non-Hodgkin lymphomas (NHL). Cryoglobulinemic vasculitis (CV) varies, ranging from mild-moderate clinical symptoms (purpura on the legs, asthenia and arthralgias) and chronic hepatitis to severe symptoms (ulcers on the legs, peripheral neuropathy, glomerulonephritis, low-grade NHL to life threatening complications (rapid progressive glomerulonephritis, gastrointestinal vasculitis, acute hyper-viscosity).

EVIDENCE ACQUISITION

CV is associated with significant morbidity and mortality. Some studies have shown kidney involvement, cirrhosis, central nervous system involvement, and heart involvement as unfavorable prognostic factors. Many studies have demonstrated that, after antiviral therapy, CV can disappear along with HCV. After the introduction of the new direct antiviral agents (DAAs), the combination of pegylated interferon and ribavirin has been abandoned.

EVIDENCE SYNTHESIS

Several studies on new DAAs have reported remarkable 90% to 100% HCV eradication rates, regardless of genotype. Treatment with DAAs has comparable efficacy on viral eradication in CV patients but definite clinical improvements of vasculitis can be observed only in half the patients.

CONCLUSIONS

In patients with mild to moderate CV disease, DAAs therapy should be used as first line approach. In patients with severe vasculitis, DAAs therapy and a second-line treatment with RTX with or without aphaeresis are a required.

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 E Virus Mediates Renal Injury via the Interaction between the Immune Cells and Renal Epithelium

Renal disorders are associated with Hepatitis E virus (HEV) infection. Progression to end-stage renal disease and acute kidney injury are complications associated with HEV infection. The mechanisms by which HEV mediates the glomerular diseases remain unclear. CD10+/CD13+ primary proximal tubular (PT) epithelial cells, isolated from healthy donors, were infected with HEV. Inflammatory markers and kidney injury markers were assessed in the presence or absence of peripheral blood mononuclear cells (PBMCs) isolated from the same donors. HEV replicated efficiently in the PT cells as shown by the increase in HEV load over time and the expression of capsid Ag. In the absence of PBMCs, HEV was not nephrotoxic, with no direct effect on the transcription of chemokines (Cxcl-9, Cxcl-10, and Cxcl-11) nor the kidney injury markers (kidney injury molecule 1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and interleukin 18 (lL-18)). While higher inflammatory responses, upregulation of chemokines and kidney injury markers expression, and signs of nephrotoxicity were recorded in HEV-infected PT cells cocultured with PBMCs. Interestingly, a significantly higher level of IFN-γ was released in the PBMCs-PT coculture compared to PT alone during HEV infection. In conclusion: The crosstalk between immune cells and renal epithelium and the signal axes IFN-γ/chemokines and IL-18 could be the immune-mediated mechanisms of HEV-induced renal disorder.

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.

Direct-acting antiviral therapy improves kidney survival in hepatitis C virus-associated cryoglobulinaemia: the RENALCRYOGLOBULINEMIC study

Background

Direct-acting antiviral agents (DAAs) have shown high rates of sustained virological response in chronic hepatitis C virus (HCV) infection. However, the influence of DAAs on the course of kidney involvement in HCV-associated mixed cryoglobulinaemia (HCV-MC) has been little studied. The aim of this study was to analyse the effects of antiviral treatment on kidney prognosis and evolution in patients diagnosed with HCV-MC.

Methods

The RENALCRYOGLOBULINEMIC study is an observational multicentre cohort study of 139 patients with HCV-MC from 14 Spanish centres. Clinical and laboratory parameters were measured before and after antiviral treatment. Primary endpoints were kidney survival and mortality after HCV-MC diagnosis. Secondary endpoints were clinical, immunological and virological responses after antiviral treatment.

Results

Patients were divided into three groups based on the treatment received: treatment with DAAs (n = 100) treatment with interferon (IFN) and ribavirin (RBV) (n = 24) and no treatment (n = 15). Patients were followed up for a median duration of 138 months (interquartile range 70-251. DAA treatment reduced overall mortality {hazard ratio [HR] 0.12 [95% confidence interval (CI) 0.04-0.40]; P < 0.001} and improved kidney survival [HR 0.10 ( 95% CI 0.04-0.33); P < 0.001].

Conclusions

Results from the RENALCRYOGLOBULINEMIC study indicated that DAA treatment in patients with HCV-MC improves kidney survival and reduces mortality.

Chinese Herbal Medicine Ameliorated the Development of Chronic Kidney Disease in Patients with Chronic Hepatitis C: A Retrospective Population-Based Cohort Study

Chronic kidney disease (CKD) is a serious complication affecting patients with chronic hepatitis. The effectiveness of CHM for the prevention of CKD in hepatitis patients remains unclear. Therefore, we conducted a retrospective cohort study to investigate the effectiveness of CHM in preventing the development of CKD in hepatitis patients. From a subdataset of the Taiwan National Health Insurance Research Database (NHIRD), we included 19,409 patients newly diagnosed with hepatitis B and hepatitis C between the years 2000 and 2010. After exclusion criteria and 1 : 1 propensity score matching process, we compared demographic factors, comorbidities, and correlated drugs between the CHM and non-CHM cohorts. Statistical analysis was applied to evaluate the differences in characteristic distributions and to compare the cumulative incidence of CKD between the CHM and non-CHM cohorts. This study showed that the patients suffering from hepatitis C with CHM treatment more than 90 days as an adjuvant therapy combined with western medical treatment modalities exhibited a decreased risk of developing CKD (hazard ratio (HR) = 0.40, 95% confidence interval (CI) = 0.21–0.76, p value <0.01). The Kaplan–Meier curve revealed a lower cumulative incidence rate of CKD (p value = 0.004) for the CHM cohort. For further reference, we herein offer the ten most frequently prescribed single herbs and herbal formulas; as such, Salviae miltiorrhizae and Jia-Wei-Xiao-Yao-San were the most commonly prescribed single herb and formula, respectively. This nationwide retrospective cohort study provides evidence that CHM is an effective adjuvant treatment to decrease the risk of developing CKD in hepatitis C patients.

Flaviviridae Viruses and Oxidative Stress: Implications for Viral Pathogenesis

Oxidative stress is induced once the balance of generation and neutralization of reactive oxygen species (ROS) is broken in the cell, and it plays crucial roles in a variety of natural and diseased processes. Infections of Flaviviridae viruses trigger oxidative stress, which affects both the cellular metabolism and the life cycle of the viruses. Oxidative stress associated with specific viral proteins, experimental culture systems, and patient infections, as well as its correlations with the viral pathogenesis attracts much research attention. In this review, we primarily focus on hepatitis C virus (HCV), dengue virus (DENV), Zika virus (ZIKV), Japanese encephalitis virus (JEV), West Nile virus (WNV), and tick-borne encephalitis virus (TBEV) as representatives of Flaviviridae viruses and we summarize the mechanisms involved in the relevance of oxidative stress for virus-associated pathogenesis. We discuss the current understanding of the pathogenic mechanisms of oxidative stress induced by Flaviviridae viruses and highlight the relevance of autophagy and DNA damage in the life cycle of viruses. Understanding the crosstalk between viral infection and oxidative stress-induced molecular events may offer new avenues for antiviral therapeutics.

Epidemiology, pathogenesis, treatment and outcomes of infection-associated glomerulonephritis

For over a century, acute 'post-streptococcal glomerulonephritis' (APSGN) was the prototypical form of bacterial infection-associated glomerulonephritis, typically occurring after resolution of infection and a distinct infection-free latent period. Other less common forms of infection-associated glomerulonephritides resulted from persistent bacteraemia in association with subacute bacterial endocarditis and shunt nephritis. However, a major paradigm shift in the epidemiology and bacteriology of infection-associated glomerulonephritides has occurred over the past few decades. The incidence of APSGN has sharply declined in the Western world, whereas the number of Staphylococcus infection-associated glomerulonephritis (SAGN) cases increased owing to a surge in drug-resistant Staphylococcus aureus infections, both in the hospital and community settings. These Staphylococcus infections range from superficial skin infections to deep-seated invasive infections such as endocarditis, which is on the rise among young adults owing to the ongoing intravenous drug use epidemic. SAGN is markedly different from APSGN in terms of its demographic profile, temporal association with active infection and disease outcomes. The diagnosis and management of SAGN is challenging because of the lack of unique histological features, the frequently occult nature of the underlying infection and the older age and co-morbidities in the affected patients. The emergence of multi-drug-resistant bacterial strains further complicates patient treatment.

Treatment of hepatitis C virus infection in patients with mixed cryoglobulinemic syndrome and cryoglobulinemic glomerulonephritis

Cryoglobulinemia is a common extrahepatic manifestation of infection with hepatitis C virus (HCV). When signs and symptoms of systemic vasculitis or glomerulonephritis occur in the presence of circulating cryoglobulins, this syndrome is called "mixed cryoglobulinemia syndrome" (MCS). Historically, interferon-based therapies in HCV have been associated with lower rates of viral cure in patients with MCS than in the general HCV-infected population. The advent of direct-acting antiviral therapies have revolutionized the treatment of HCV, dramatically increasing rates of cure. Early studies of first-generation protease inhibitors (telaprevir and boceprevir) in combination with interferon and ribavirin demonstrated HCV cure rates of 67% and complete clinical response rates of vasculitis symptoms in 60% of patients with MCS; however, regimens were poorly tolerated by patients, 22% discontinued treatment early. More recently, all-oral, interferon-free regimens have become available and combination therapies are now being approved for patients with and without renal impairment. Patients with HCV-MCS achieved sustained virologic response in 297 out of 313 patients (95%) treated with direct-acting antiviral therapy, and 85% had a complete or partial clinical response of MCS symptoms. Current direct-acting antiviral therapies are well tolerated in patients with HCV-MCS and only 1.6% discontinued treatment early. Patients with cryoglobulinemic glomerulonephritis also had an excellent cure rate (94%). The majority improved; 17/52 (33%) experienced full remission and 15/52 (29%) experienced partial remission. There were no reports of worsening kidney function in patients treated with direct-acting antiviral therapies. Less than 5% of patients with HCV-MCS treated with IFN-free direct-acting antiviral therapy required immunosuppression. However, patients with severe vasculitis appear to still require concomitant immunosuppression.

HCV-Associated Nephropathies in the Era of Direct Acting Antiviral Agents

Hepatitis C virus (HCV) infection is a systemic disorder that frequently associates with extrahepatic manifestations, including nephropathies. Cryoglobulinemia is a typical extrahepatic manifestation of HCV infection that often involves kidneys with a histological pattern of membranoproliferative glomerulonephritis. Other, less common renal diseases related to HCV infection include membranous nephropathy, focal segmental glomerulosclerosis, IgA nephropathy, fibrillary and immunotactoid glomerulopathy. Over the last decades, the advent of direct-acting antiviral therapies has revolutionized treatment of HCV infection, dramatically increasing the rates of viral clearance. In patients where antiviral therapy alone fails to induce renal disease remission add-on B-cell depleting agents represent an alternative to counteract the synthesis of pathogenic antibodies. Immunosuppressive therapies, such as steroids, alkylating agents, and plasma exchanges, may still represent an effective option to inhibit immune-complex driven inflammatory response, but the potentially associated increase of HCV replication and worsening of liver disease represent a serious limitation to their use.

Correlation Between Tenofovir Drug Levels and the Renal Biomarkers RBP-4 and ß2M in the ION-4 Study Cohort

Background

Concomitant dosing of ledipasvir (LDV) and tenofovir disoproxil fumarate (TDF) results in an increased tenofovir (TFV) area under the curve (AUC). The aim of this study was to examine whether there was a correlation between the renal biomarkers retinol binding protein–4 (RBP-4) and β2 microglobulin (β2M) and tenofovir AUC.

Methods

The ION-4 trial enrolled HIV/hepatitis C virus–coinfected patients on nonpharmacologically boosted antiretroviral regimens with TDF-containing backbones. We assessed for a correlation between tenofovir AUC and urinary biomarkers and also for changes in serologic biomarkers with respect to clinically relevant changes in renal function (creatinine clearance decrease >25%, change in creatinine >0.2 mg/dL, change in proteinuria from negative/trace to ≥1+).

Results

Three hundred thirty-five patients were enrolled in the ION-4 study; their demographic characteristics have been previously described. Both RBP-4 and β2M exhibited positive correlations with tenofovir AUC. Baseline and study levels of RBP-4 and β2M were higher for patients with increases in urine proteinuria and an absolute creatinine increase.

Conclusions

TFV exposure is associated with increased proximal tubule urine biomarkers in participants on ledipasvir/sofosbuvir and nonpharmacologically boosted TDF-based antiretroviral regimens. Baseline proximal tubule biomarkers may predict nephrotoxicity risk if events are prevalent. Further studies assessing the predictive role of these urine biomarkers may help guide medical decision-making and risk/benefit assessments in patients with risk factors for renal dysfunction.

Treatment of chronic hepatitis C viral infection with sofosbuvir and daclatasvir in kidney transplant recipients

OBJECTIVES

To assess the efficacy and the risk of sofosbuvir-daclatasvir treatment among kidney transplant recipients (KTRs) with chronic hepatitis C virus (HCV) infection.

METHODS

A real-life retrospective cohort analysis was performed on KTRs treated with sofosbuvir-daclatasvir at our center between January 2016 and March 2018. We collected data from 19 KTRs (13 males; age 48.3 ± 9.6 years; HCV genotype I, n = 16; chronic active hepatitis B coinfection, n = 8). Virological and clinical data were assessed.

RESULTS

Overall, 100% of the patients had achieved a sustained virological response 12 weeks after treatment (SVR12). Their liver function improved notably, with a significant decline in the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels (ALT 34.8 ± 18.6 IU/L pre-treatment and 15.0 ± 6.8 IU/L post-treatment, P = 0.0003; AST: 35.05 ± 18.1 IU/L pre-treatment and 19.1 ± 7.0 post-treatment, P = 0.001). A significant amelioration was observed in patients with proteinuria (n = 12) (0.95 [0.35-3.31] g/g at baseline to 0.39 [0.27-1.02] g/g post-therapy, P = 0.048). The serum creatinine, eGFR, and tacrolimus levels were stable during therapy.

CONCLUSION

The preliminary data demonstrated that sofosbuvir-daclatasvir was highly effective in treating HCV infection in KTRs with acceptable tolerance.

Successful recovery of associated interstitial nephritis and focal segmental glomerulosclerosis in patients with HCV and HIV treated with sofosbuvir and daclatasvir and revision of literature

In this report, we describe the coexistence of two rare and debated complications of hepatitis C virus (HCV) infection: interstitial nephritis, with associated focal glomerulosclerosis, and autoimmune hepatitis, in a 55-year-old HIV/HCV-coinfected woman. The patient was treated for the immune-mediated manifestations with mycophenolate mofetil, which she continued for 9 years, as symptoms relapsed at every attempt to discontinue immunosuppression. The patient finally cleared HCV infection thanks to new direct-acting agents and could discontinue immunosuppressive therapy maintaining stable conditions and laboratory parameters after 24-weeks follow-up.

Autoimmune Kidney Diseases Associated with Chronic Viral Infections

Autoimmune kidney diseases triggered by viruses are an important cause of kidney disease in patients affected by chronic viral infection. Hepatitis B virus (HBV) infection is associated with membranous nephropathy and polyarteritis nodosa. Hepatitis C virus (HCV) infection is a major cause of cryoglobulinemic glomerulonephritis. Patients with human immunodeficiency virus (HIV) may develop HIV-associated nephropathy, a form of collapsing focal segmental glomerulosclerosis, or various forms of immune-complex-mediated kidney diseases. This article summarizes what is known about the pathogenesis, diagnosis, and management of immune-mediated kidney diseases in adults with chronic HBV, HCV, and HIV infections.

Are direct-acting antivirals safe and effective in hepatitis C virus-cryoglobulinemia? virological, immunological, and clinical data from a real-life experience

OBJECTIVES

Hepatitis C virus (HCV) is the major cause of cryoglobulinemia. Direct-acting antivirals (DAAs) have markedly changed the therapeutic outcomes in the treatment of patients with HCV. We evaluate the efficacy, safety, immunological, and clinical response of different DAA regimens in HCV-cryoglobulinemia.

PATIENTS AND METHODS

Ninety-three cryoglobulinemic patients, divided into symptomatic [symptomatic cryoglobulinemic patients (SCP; n=35)] and asymptomatic [nonsymptomatic cryoglobulinemic patients (NSCP; n=60)], underwent DAAs. Eighty-nine comparable noncryoglobulinemic patients were selected as a control group. We evaluated the sustained virological response (SVR), the adverse effects, and the immune and symptomatic response.

RESULTS

Percentages of patients who achieved SVR and experienced adverse effects were not statistically different between the three groups (100, 95, 93.3% and 57.1, 53.3, 48.3%). In 68.5% of SCP and in 76.7% of NSCP, cryoglobulins disappeared at SVR. No risk factor was associated with the persistence of cryoglobulins. An increase was observed both in C4 (P=0.002; P=0.018) and in C3 (P=0.0037; P=0.031) in SCP and NSCP. About 70% of symptomatic patients showed a complete or partial symptomatic remission: persistence of symptoms is correlated to the type of clinical picture.

CONCLUSION

DAA regimens are safe and effective in patients with HCV-cryoglobulinemia. The achievement of SVR is necessary, but not sufficient, to achieve a complete immunological and clinical response.

[Chronic hepatitis C virus infection: An internist's opinion (Part 1)]

Hepatitis C virus (HCV) infection results in not only chronic hepatitis and subsequent complications as liver cirrhosis and hepatocellular carcinoma, but also in a significant number of other diseases, the so-called extrahepatic manifestations of chronic HCV infection. This is because of viral hepatotropicity and lymphotropicity. The most striking example of the course of chronic HCV infection, in which the infectious and inflammatory processes are concurrent with autoimmune disorders and carcinogenesis, is mixed cryoglobulinemia and B-cell non-Hodgkin's lymphoma. The pathogenesis of these diseases is based on the clonal expansion of B cells, which occurs under their prolonged stimulation with the virus or viral proteins. Part 1 of this review is devoted to the analysis of a correlation of chronic HCV infection with lymphoproliferative and autoimmune disorders, as well as its association with kidney injury.

Improvement of Proteinuria due to Combination Therapy with Daclatasvir and Asunaprevir in Hepatitis C Virus-associated Renal Disease without Cryoglobulinemia

We herein report a unique case of hepatitis C virus (HCV)-associated renal disease without cryoglobulinemia that showed proteinuria, hypoproteinemia, ascites, and edema. Due to combination therapy with daclatasvir and asunaprevir, the patient achieved sustained virological response at week 24 of the therapy. Furthermore, the therapy caused marked amelioration of her proteinuria, ascites, edema, and hypoalbuminemia, and finally improved her estimated glomerular filtration rate. There were no adverse events, and the combination therapy was well-tolerated. We recommend that HCV eradication with antiviral therapy using direct-acting antiviral agents be attempted first for all renal disease with HCV infection, regardless of cryoglobulinemia, considering the existence of resistance-associated variants.

Achieving Sustained Virological Response in Liver Transplant Recipients With Hepatitis C Decreases Risk of Decline in Renal Function

The effect of antiviral therapy (AVT) on kidney function in liver transplantation (LT) recipients has not been well described despite known association of hepatitis C virus (HCV) infection with chronic kidney disease (CKD). We compared the incidence of CKD and end-stage renal disease (ESRD) in 204 LT recipients with HCV based on treatment response to AVT. The mean estimated glomerular filtration rate (eGFR) at baseline (3 months after LT) was similar in the sustained virological response (SVR; n = 145) and non-SVR group (n = 59; 69 ± 21 versus 65 ± 33 mL/minute/1.73 m² ; P = 0.27). In the unadjusted Cox proportional regression analysis, the presence of SVR was associated with an 88% lower risk of CKD (hazard ratio, 0.12; 95% confidence interval [CI], 0.05-0.31) and 86% lower risk of ESRD (odds ratio, 0.14; 95% CI, 0.05-0.35). Similar results were found after adjusting for propensity score and time-dependent Cox regression analyses. The estimated slopes of eGFR based on a 2-stage mixed model of eGFR were calculated. Patients with SVR had a less steep slope in eGFR (-0.60 mL/minute/1.73 m² /year; 95% CI, -1.50 to 0.30; P = 0.190) than recipients without SVR (-2.53 mL/minute/1.73 m² /year; 95% CI, -3.99 to -1.07; P = 0.001), and the differences in the slopes were statistically significant (P = 0.026). In conclusion, in LT recipients with chronic HCV infection, achieving SVR significantly lowers the risk of decline in renal function and progression to ESRD independent of the AVT therapy used.

Hepatitis C virus infection in chronic kidney disease: paradigm shift in management

Hepatitis C virus (HCV) infection in chronic kidney disease (CKD) is associated with increased liver-related morbidity and mortality rates, accelerated progression to end-stage renal disease, and risk of cardiovascular events. CKD patients with HCV infection require antiviral therapy. Pegylated interferon (peg-IFN) plus ribavirin was the standard of care for HCV-infected CKD patients before the introduction of first-generation direct-acting antiviral (DAA) oral anti-HCV agents. Peg-IFN-based treatment has a low virologic response rate and poor compliance, resulting in a high dropout rate. Recently, several clinical trials of all-DAA combination regimens have reported excellent antiviral efficacy and few adverse drug reactions in HCV-infected patients with CKD. These positive results have revolutionized the treatment of chronic HCV infection in this population. In this review, we address the impact of chronic HCV infection in CKD patients, and discuss their management using next-generation DAAs.