Are Kidneys Affected by SARS-CoV-2 Infection? An Updated Review on COVID-19-Associated AKI

BACKGROUND

Human kidneys are an important target of SARS-CoV-2 infection, and many renal abnormalities have been found in patients with SARS-CoV-2 infection, including proteinuria, hematuria, and acute kidney injury. Acute kidney injury is now considered a common complication of COVID-19, and the epidemiology of AKI in SARS-CoV-2-infected patients continues to be controversial.

AIM AND METHODS

We have carried out a narrative review to evaluate the frequency and risk factors for AKI among patients hospitalized due to COVID-19, and the latest surveys on this topic have been included. The mechanisms by which AKI occurs in COVID-19 patients have also been reviewed.

RESULTS

Multiple risk factors for the development of AKI in patients with SARS-CoV-2 infection have been identified; these have been classified in various groups (management and background factors, among others). SARS-CoV-2 targets the kidneys by indirect activity, but SARS-CoV-2 infects tubular epithelial cells and podocytes. We retrieved 24 reports (n = 502,593 unique patients with SARS-CoV-2 infection) and found an incidence of AKI of 31.8% (range, 0.5% to 56.9%). Only a minority (n = 2) of studies had a prospective design. We found that the AKI risk was greater in SARS-CoV-2 patients who underwent in-hospital deaths vs. those who survived; the summary estimate of the unadjusted RR of AKI was 2.63 (95% CI, 2.37; 2.93) (random-effects model). A stratified analysis showed that the incidence of AKI was greater in those reports where the frequency of COVID-19-positive patients having comorbidities (diabetes mellitus, arterial hypertension, and advanced age) was high. The unadjusted relative risk (aRR) of AKI was greater in SARS-CoV-2 patients who underwent ICU admission vs. those who did not; the pooled estimate of AKI risk was 2.64 (95% CI, 1.96; 3.56) according to the random-effects model.

CONCLUSIONS

AKI is a common complication of hospitalized SARS-CoV-2-infected patients, and some comorbidities are important risk factors for it. The direct activity of the virus on the kidneys has been mentioned in the pathogenesis of AKI in SARS-CoV-2 patients. Further studies are ongoing in order to identify the mechanisms underlying the kidney injury in this population. The role of AKI on survival in SARS-CoV-2-infected patients is another area of active investigation.

Prevention, Diagnosis, Evaluation, and Treatment of Hepatitis C in Chronic Kidney Disease: Synopsis of the Kidney Disease: Improving Global Outcomes 2022 Clinical Practice Guideline

DESCRIPTION

The Kidney Disease: Improving Global Outcomes (KDIGO) 2022 clinical practice guideline on prevention, diagnosis, evaluation, and treatment of hepatitis C in chronic kidney disease (CKD) is an update of the 2018 guideline from KDIGO.

METHODS

The KDIGO Work Group (WG) updated the guideline, which included reviewing and grading new evidence that was identified and summarized. As in the previous guideline, the WG used the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach to appraise evidence and rate the strength of recommendations and used expert judgment to develop recommendations. New evidence led to updating of recommendations in the chapters on treatment of hepatitis C virus (HCV) infection in patients with CKD (Chapter 2), management of HCV infection before and after kidney transplant (Chapter 4), and diagnosis and management of kidney disease associated with HCV infection (Chapter 5). Recommendations in chapters on detection and evaluation of hepatitis C in CKD (Chapter 1) and prevention of HCV transmission in hemodialysis units (Chapter 3) were not updated because of an absence of significant new evidence.

RECOMMENDATIONS

The 2022 updated guideline includes 43 graded recommendations and 20 ungraded recommendations, 7 of which are new or modified on the basis of the most recent evidence and consensus among the WG members. The updated guidelines recommend expanding treatment of hepatitis C with sofosbuvir-based regimens to patients with CKD glomerular filtration rate categories G4 and G5, including those receiving dialysis; expanding the donor pool for kidney transplant recipients by accepting HCV-positive kidneys regardless of the recipient's HCV status; and initiating direct-acting antiviral treatment of HCV-infected patients with clinical evidence of glomerulonephritis without requiring kidney biopsy. The update also addresses the use of immunosuppressive regimens in such patients.

Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

Executive Summary of the KDIGO 2022 Clinical Practice Guideline for the Prevention, Diagnosis, Evaluation, and Treatment of Hepatitis C in Chronic Kidney Disease

Infection with the hepatitis C virus (HCV) has adverse liver, kidney, and cardiovascular consequences in patients with chronic kidney disease (CKD), including those on dialysis therapy or with a kidney transplant. Since the publication of the Kidney Disease: Improving Global Outcomes (KDIGO) HCV Guideline in 2018, advances in HCV management, particularly in the field of antiviral therapy and treatment of HCV-associated glomerular diseases, coupled with increased usage of HCV-positive kidney grafts, have prompted a reexamination of the 2018 guideline. As a result, the Work Group performed a comprehensive review and revised the 2018 guidance. This Executive Summary highlights key aspects of the updated guideline recommendations for 3 chapters: Chapter 2: Treatment of HCV infection in patients with CKD; Chapter 4: Management of HCV-infected patients before and after kidney transplantation; and Chapter 5: Diagnosis and management of kidney diseases associated with HCV infection.

'Real-life' experience with direct-acting antiviral agents for HCV after kidney transplant

INTRODUCTIONS AND OBJECTIVES

The introduction of direct-acting antiviral (DAA) agents promises to change dramatically the management of hepatitis C in kidney transplant recipients, a patient group where the treatment of hepatitis C is historically challenging. The purpose of the current study was to assess (in a 'real-life' setting) the safety and efficacy of all-oral, interferon-free, direct-acting antiviral agents in kidney transplant recipients with HCV.

MATERIAL AND METHODS

We performed a single-arm, multi-center study in a cohort (n = 95) of kidney transplant recipients who underwent antiviral therapy with DAAs. The primary end-point was sustained virologic response (SVR) (serum HCV RNA < 15 IU/mL, 12 weeks after treatment ended; SVR12). We recorded data on on-treatment adverse events (AEs), serious AEs, and laboratory abnormalities.

RESULTS

Various regimens were adopted at the discretion of the treating physician: elbasvir/grazoprevir (n = 11), paritaprevir/ritonavir/ombitasvir/dasabuvir (PrOD) regimens ± ribavirin (n = 23), and sofosbuvir-based regimens ± ribavirin (n = 61). The SVR12 rate was 93.7% (89/95) (95% CI, 88%; 98%), according to intention-to-treat analysis; three patients without viral response (n = 3) were found. Ribavirin was administered in 8 (8.4%) allograft recipients. The frequency of drop-outs was 4.2% (4/95) (95% CI, 0.2%; 8.2%); these were related to arthralgia/myalgia (n = 2), fatigue (n = 1), and lowered estimated glomerular filtration rate (eGFR) (n = 1). There were no differences with regard to serum creatinine and eGFR before and after antiviral therapy and during follow-up in the whole cohort. The patient who interrupted antiviral treatment due to raised serum creatinine was on sofosbuvir/daclatasvir regimen; one of the four drop-outs obtained SVR.

CONCLUSIONS

All-oral, interferon-free therapy with DAAs for chronic HCV after kidney transplantation was effective and well-tolerated in a 'real-life' clinical setting. Identical results have been observed in patients with intact kidneys or advanced chronic kidney disease. Careful evaluation of kidney function over follow-up in kidney transplant recipients who received DAAs regimens is recommended. Clinical trials aimed to assess whether sustained viral response translates into improved patient/graft survival are under way.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

BACKGROUND AND RATIONALE

Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear.

MATERIAL AND METHODS

We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009-December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60mL/min/1.73m²), mild CKD (eGFR, 30-59mL/min/1.73m²), severe CKD (eGFR, 15-29mL/min/1.73m²), and end-stage renal disease (ESRD).

RESULTS

We enrolled 410 patients followed for 53.2±32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P=0.044), raised levels of serum uric acid (P<0.0001), and insulin dependent DM (P=0.0034). Early post-transplant AKI was common (n=95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P=0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P<0.0001), early post-transplant AKI (P=0.007), and baseline serum creatinine (P=0.0002). At the end of follow-up, there were 116 LT recipients with CKD - 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis.

CONCLUSION

The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.

An Updated View on the Antiviral Therapy of Hepatitis C in Chronic Kidney Disease

BACKGROUND

Hepatitis C virus infection remains common in patients with chronic kidney disease, including those on maintenance dialysis. The relationship between hepatitis C virus infection and chronic kidney disease is bi-directional; in fact, HCV is both a cause and consequence of chronic kidney disease. According to a systematic review with meta-analysis of observational studies (n = 23 studies) (n = 574,081 patients on long-term dialysis), anti-HCV positive serologic status was an independent and significant risk factor for death in patients with advanced chronic kidney disease on long-term dialysis. The overall estimate for adjusted mortality (all-cause death risk) with HCV was 1.26 (95% CI, 1.18; 1.34) (p < 0.0001). Interferon-based therapies are biased by low efficacy/safety in chronic kidney disease, but the advent of direct-acting antiviral drugs has made a paradigm shift in the treatment of HCV-infection. These medications give interruption of viral replication because they target specific non-structural viral proteins; four classes of DAAs exist-NS3/4A protease inhibitors, NS5A inhibitors, NS5B nucleoside and non-nucleoside polymerase inhibitors. All-oral, interferon-free, ribavirin-free combinations of DAAs are now available.

AIM

The goal of this narrative review is to report the available treatment options for HCV in advanced chronic kidney disease.

METHODS

We have made an extensive review of the medical literature and various research engines have been adopted.

RESULTS

Some combinations of DAAs are currently recommended for HCV in advanced CKD (including patients on maintenance dialysis): elbasvir/grazoprevir; glecaprevir/pibrentasvir; and sofosbuvir-based regimens. Solid evidence, based on registration and "real life" studies supports their efficacy (SVR rates > 90%) and safety even in patients with advanced CKD. No dosage adjustment is necessary and treatment duration is 8-12 weeks. However, recent data highlight that many patients with advanced CKD remain untreated, and numerous barriers to antiviral treatment of HCV still exist. Whether successful antiviral therapy with DAAs will translate into improved survival in the advanced CKD population is another point of future research.

Updated Evidence on the Epidemiology of Hepatitis C Virus in Hemodialysis

Prevalence rates of HCV infection are decreasing in hemodialysis units of most developed countries; however, nosocomial transmission of HCV continues to occur in the hemodialysis setting, not only in the emerging world. According to the Dialysis Outcomes and Practice Patterns Study (DOPPS, 2012–2015), the prevalence of HCV among patients on regular hemodialysis was 9.9%; in incident patients, the frequency of HCV was approximately 5%. Outbreaks of HCV have been investigated by epidemiologic and phylogenetic data obtained by sequencing of the HCV genome; no single factor was retrieved as being associated with nosocomial transmission of HCV within hemodialysis units. Transmission of HCV within HD units can be prevented successfully by full compliance with infection control practices; also, antiviral treatment and serologic screening for anti-HCV can be useful in achieving this aim. Infection control practices in hemodialysis units include barrier precautions to prevent exposure to blood-borne pathogens and other procedures specific to the hemodialysis environment. Isolating HCV-infected hemodialysis patients or using dedicated dialysis machines for HCV-infected patients are not currently recommended; reuse of dialyzers of HCV-infected patients should be made, according to recent guidelines. Randomized controlled trials regarding the impact of isolation on the risk of transmission of HCV to hemodialysis patients have not been published to date. At least two studies showed complete elimination of de novo HCV within HD units by implementation of strict infection control practices without isolation practices. De novo HCV within hemodialysis units has been independently associated with facility HCV prevalence, dialysis vintage, and low staff-to-patient ratio. Antiviral treatment of HCV-infected patients on hemodialysis should not replace the implementation of barrier precautions and other routine hemodialysis unit procedures.

Sofosbuvir-based regimens for HCV in stage 4-stage 5 chronic kidney disease. A systematic review with meta-analysis

BACKGROUND

Hepatitis C is an important agent of liver damage in patients with chronic kidney disease and the advent of DAAs has dramatically changed the management of HCV positive patients, including those with advanced CKD. Sofosbuvir is the backbone of many anti-HCV regimens based on DAAs but it remains unclear whether it is appropriate for HCV-infected patients with stage 4-5 CKD.

STUDY AIMS AND DESIGN

We performed a systematic review of the literature with a meta-analysis of clinical studies in order to evaluate the efficacy and safety of SOF-based DAA regimens in patients with stage 4-5 CKD. The primary outcome was sustained viral response (as a measure of efficacy); the secondary outcomes were the frequency of SAEs and drop-outs due to AEs (as measures of tolerability). The random-effects model of DerSimonian and Laird was adopted, with heterogeneity and stratified analyses.

RESULTS

Thirty clinical studies (n=1537 unique patients) were retrieved. The pooled SVR12 and SAEs rate was 0.99 (95% confidence intervals, 0.97; 1.0, I²=99.8%) and 0.09 (95% CI, 0.05; 0.13, I²=84.3%), respectively. The pooled SVR12 rate in studies with high HCV RNA levels at baseline was lower, 0.87 (95% CI, 0.75; 1.0, I²=73.3%) (P<0.001). The pooled drop-out rate due to AEs was 0.02 (95% CI, -0.01; 0.04, I²=16.1%). Common serious adverse events were anemia (n=26, 38%) and reduced eGFR (n=14, 19%). SAEs were more common in studies adopting full-dose sofosbuvir (pooled rate of SAEs 0.15, 95% CI, 0.06; 0.25; I²=80.1%) and in those based on ribavirin (0.15, 95% CI, 0.07; 0.23, I²=95.8%). Six studies (n=69 patients) reported eGFR levels at baseline/post- antiviral therapy; no consistent changes were found.

CONCLUSIONS

SOF-based regimens appear safe and effective in patients with stage 4-5 CKD. Serum creatinine should be carefully monitored during therapy with SOF in patients with CKD. Randomized controlled studies in order to expand our knowledge on this point are under way.

HBV infection is a risk factor for chronic kidney disease: Systematic review and meta-analysis

BACKGROUND

The activity of hepatitis B virus (HBV) as a risk factor for the incidence and progression of chronic kidney disease (CKD) has not been clarified.

AIM

We evaluated the impact of infection with HBV on the risk of CKD in the general population.

MATERIAL AND METHODS

We carried out a systematic review of the published medical literature to assess whether a relationship between hepatitis B infection and an increased risk of CKD in the adult general population occurs. We adopted the random effects model of DerSimonian and Laird to provide a summary estimate of the risk of chronic kidney disease (defined by lowered glomerular filtration rate and/or detectable proteinuria) with HBV infection across the published studies. Meta-regression and stratified analyses were also performed.

RESULTS

We retrieved 33 studies (n = 7,849,849 patients) published in 26 different articles, and separate meta-analyses were performed according to the outcome. Pooling results from cohort studies (11 studies, n = 1,056,645 patients) demonstrated a relationship between positive HBV serologic status and increased incidence of CKD, the summary estimate for adjusted HR with HBV across the surveys, 1.40 (95% CI, 1.16-1.69) (P < .001). Between-study heterogeneity was noted (Q value, 49.5, P < .0001). No relationship between HBV and prevalence of CKD was noted in the subset of cross-sectional studies (10 studies; n = 3,222,545 patients), adjusted OR, 1.04 (95% IC 0.90-1.218; P = .5). Meta-regression analysis reported a relationship between positive HBsAg status and incidence of CKD in the general population (P < .015).

CONCLUSIONS

It appears that exposure to HBV infection seems to be associated with an increased risk of developing CKD in the adult general population. Studies aimed to understand the mechanisms responsible of such association are under way.

Sofosbuvir-based regimens for HCV in stage 4-stage 5 chronic kidney disease. A systematic review with meta-analysis

BACKGROUND

Hepatitis C is an important agent of liver damage in patients with chronic kidney disease and the advent of DAAs has dramatically changed the management of HCV positive patients, including those with advanced CKD. Sofosbuvir is the backbone of many anti-HCV regimens based on DAAs but it remains unclear whether it is appropriate for HCV-infected patients with stage 4-5 CKD.

STUDY AIMS AND DESIGN

We performed a systematic review of the literature with a meta-analysis of clinical studies in order to evaluate the efficacy and safety of SOF-based DAA regimens in patients with stage 4-5 CKD. The primary outcome was sustained viral response (as a measure of efficacy); the secondary outcomes were the frequency of SAEs and drop-outs due to AEs (as measures of tolerability). The random-effects model of DerSimonian and Laird was adopted, with heterogeneity and stratified analyses.

RESULTS

Thirty clinical studies (n=1537 unique patients) were retrieved. The pooled SVR12 and SAEs rate was 0.99 (95% confidence intervals, 0.97; 1.0, I²=99.8%) and 0.09 (95% CI, 0.05; 0.13, I²=84.3%), respectively. The pooled SVR12 rate in studies with high HCV RNA levels at baseline was lower, 0.87 (95% CI, 0.75; 1.0, I²=73.3%) (P<0.001). The pooled drop-out rate due to AEs was 0.02 (95% CI, -0.01; 0.04, I²=16.1%). Common serious adverse events were anemia (n=26, 38%) and reduced eGFR (n=14, 19%). SAEs were more common in studies adopting full-dose sofosbuvir (pooled rate of SAEs 0.15, 95% CI, 0.06; 0.25; I²=80.1%) and in those based on ribavirin (0.15, 95% CI, 0.07; 0.23, I²=95.8%). Six studies (n=69 patients) reported eGFR levels at baseline/post- antiviral therapy; no consistent changes were found.

CONCLUSIONS

SOF-based regimens appear safe and effective in patients with stage 4-5 CKD. Serum creatinine should be carefully monitored during therapy with SOF in patients with CKD. Randomized controlled studies in order to expand our knowledge on this point are under way.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study

BACKGROUND AND RATIONALE

Chronic kidney disease remains an important risk factor for morbidity and mortality among LT recipients, but its exact incidence and risk factors are still unclear.

MATERIAL AND METHODS

We carried out a retrospective cohort study of consecutive adults who underwent liver transplant (January 2009-December 2018) and were followed (at least 6 months) at our institution. CKD was defined following the Kidney Disease: Improving Global Outcomes (KDIGO) 2012 Clinical Practice Guidelines. Long-term kidney function was classified into 4 groups: no CKD (eGFR, ≥60mL/min/1.73m2), mild CKD (eGFR, 30-59mL/min/1.73m2), severe CKD (eGFR, 15-29mL/min/1.73m2), and end-stage renal disease (ESRD).

RESULTS

We enrolled 410 patients followed for 53.2±32.6 months. 39 had CKD at baseline, and 95 developed de novo CKD over the observation period. There were 184 (44.9%) anti-HCV positive, 47 (11.5%) HBsAg positive, and 33 (8.1%) HBV/HDV positive recipients. Recipient risk factors for baseline CKD were advanced age (P=0.044), raised levels of serum uric acid (P<0.0001), and insulin dependent DM (P=0.0034). Early post-transplant AKI was common (n=95); logistic regression analysis found that baseline serum creatinine was an independent predictor of early post-LT AKI (P=0.0154). According to our Cox proportional hazards model, recipient risk factors for de novo CKD included aging (P<0.0001), early post-transplant AKI (P=0.007), and baseline serum creatinine (P=0.0002). At the end of follow-up, there were 116 LT recipients with CKD - 109 (93.9%) and 7 (6.1%) had stage 3 and advanced CKD, respectively. Only two of them are undergoing long-term dialysis.

CONCLUSION

The incidence of CKD was high in our cohort of LT recipients, but only a slight decline in kidney function over time was recorded. Prevention of post-transplant AKI will improve kidney function in the long run. We need more studies to analyze the function of kidneys among LT recipients over extended follow-ups and their impact on mortality.

Impact of antiviral therapy with Direct Acting Antiviral Agents (DAAs) on kidney disease in patients with chronic hepatitis C

Hepatitis C virus and chronic kidney disease are major public health issues all over the world and controversy persists regarding the role of hepatitis C as a risk factor for the development of chronic kidney disease in the adult general population. Numerous studies found a relationship between positive anti-HCV antibody serologic prevalence and increased frequency of incidence, prevalence and accelerated progression of CKD over time. However, this has not been universally accepted. One method to analyze the relationship between anti-HCV status and CKD is to evaluate the impact of anti-HCV antiviral therapy on the risk of CKD in the general population. The availability of safe and effective drugs (direct-acting antiviral agents) for HCV eradication support this approach. Novel data support the notion that sustained viral response with anti-HCV regimens leads to improvement of hepatic and extra-hepatic outcomes. A systematic review with metaanalysis of clinical observational studies was recently performed on this point. Fifteen studies were retrieved (n=356, 285 patients); a relationship between sustained viral response and lower rate of kidney disease was noted- the summary estimate for adjusted risk of kidney disease was 2.5 (95% CI, 1.41; 4.41) (P=0.0016). An association between anti-HCV therapy and reduced risk of kidney disease after comparison of treated vs. untreated cohorts was observed, the summary estimate for adjusted HR was 0.44 (95% CI, 0.25; 0.63) (P=0.0001). Several biologic mechanisms have been cited to explain the detrimental role of HCV on kidney disease in the general population, and a direct and indirect activity of HCV on atherogenesis at kidney level has been mentioned. Clinical and experimental studies are under way.

Hepatitis B virus vaccine and chronic kidney disease. The advances

BACKGROUND

Hepatitis B is an important agent of liver disease in patients with chronic kidney disease and chronic HBV infection promotes the development of CKD in the adult general population. Patients with CKD have a suboptimal response to various vaccines, and it remains unclear how we boost the immune response of CKD patients to HB vaccine.

STUDY AIMS AND DESIGN

We performed a narrative review to assess the mechanisms of lower immunogenicity of HBV vaccine in CKD population; multiple approaches to improve the response rate of CKD patients to HBV vaccine have been reported. This is a very important topic for nephrologists who often serve as primary case providers for patients with CKD.

RESULTS

The recommended vaccine schedule for CKD patients including those on maintenance dialysis is based on recombinant vaccine, four doses (month 0,1,2, and 6; 40mcg each) by intramuscular route (deltoid muscle). According to RCTs or observational studies, some recombinant vaccines with adjuvants (i.e., HBV-AS02 and HBV-AS04) look promising. HBV-AS04 showed to give better seroprotection rates and durable immune response over extended follow-ups compared with licensed HBV vaccine in CKD patients. The seroprotection rate was 95% (97/102) and 82% (202/248) in pre-dialysis and dialysis patients, respectively, one month after completing vaccine schedule with HBV-AS04. HBV-AS02 was superior to licensed vaccine in terms of seroprotection rate, 76.9% vs. 37.6%.

CONCLUSIONS

We suggest adjuvanted recombinant (HBV-AS04) vaccine (0,1,2 and 3 months; 20 mcg each dose) and post vaccination testing of anti-HBs antibody after vaccination. Booster doses to patients whose anti-HBs titers fall below the seroprotection level (<10IU/mL) during the follow-up are appropriate. The patho-physiologic mechanisms responsible for the poor immunogenicity of HBV vaccine in CKD patients are under active investigation.

Ribavirin as a beneficial treatment option for hepatitis C virusassociated glomerular disease

The management of hepatitis C virus (HCV)-induced glomerular disease remains unsatisfactory despite novel advances in antiviral and immunosuppressive therapy. Recent evidence highlighted the role of ribavirin, a drug provided with immunomodulatory properties, in the treatment of glomerular diseases associated with chronic HCV. We administered low-dose ribavirin (200 mg/day or 200 mg twice a week or 200 mg thrice weekly) in a prospective fashion to a group of patients with HCV-associated glomerular disease (n = 7). Ribavirin monotherapy was given in most (n = 6) patients and was accompanied by erythropoietin therapy in all. The primary endpoint was reduction of 24-h proteinuria after treatment ended; the secondary end-points were decrease in serum creatinine and amelioration of urinary abnormalities. We collected data on on-treatment adverse events (AEs), serious AEs, and laboratory abnormalities. Many patients (n = 6) had inactive HCV infection as they had shown HCV RNA clearance from serum after antiviral therapy with direct-acting antivirals. Some patients (n = 4) had membranoproliferative glomerulo- nephritis, the diagnosis being confirmed by kidney histology in three cases; others (n = 2) received diagnosis of diabetic glomerulosclerosis, confirmed in one by kidney biopsy. We observed consistent reduction of 24-h proteinuria in two individuals after ribavirin therapy; another patient reported disappearance of microscopic hematuria. We found severe AE (hemolytic anemia) in three patients which required discontinuation of ribavirin treatment in two patients, one required hospitalization. Other AEs were cutaneous rash (n = 1), dyspepsia (n = 1), and fatigue (n = 1). Low-dose ribavirin was able to give consistent reduction of 24-h proteinuria in two patients; tolerance to ribavirin was unsatisfactory. We need further studies aimed to expand our knowledge on ribavirin therapy of HCV-associated glomerular disease. The low incidence of the disease hampers the conduction of clinical trials on this aim.

Hepatitis B virus vaccine and chronic kidney disease. The advances

BACKGROUND

Hepatitis B is an important agent of liver disease in patients with chronic kidney disease and chronic HBV infection promotes the development of CKD in the adult general population. Patients with CKD have a suboptimal response to various vaccines, and it remains unclear how we boost the immune response of CKD patients to HB vaccine.

STUDY AIMS AND DESIGN

We performed a narrative review to assess the mechanisms of lower immunogenicity of HBV vaccine in CKD population; multiple approaches to improve the response rate of CKD patients to HBV vaccine have been reported. This is a very important topic for nephrologists who often serve as primary case providers for patients with CKD.

RESULTS

The recommended vaccine schedule for CKD patients including those on maintenance dialysis is based on recombinant vaccine, four doses (month 0,1,2, and 6; 40mcg each) by intramuscular route (deltoid muscle). According to RCTs or observational studies, some recombinant vaccines with adjuvants (i.e., HBV-AS02 and HBV-AS04) look promising. HBV-AS04 showed to give better seroprotection rates and durable immune response over extended follow-ups compared with licensed HBV vaccine in CKD patients. The seroprotection rate was 95% (97/102) and 82% (202/248) in pre-dialysis and dialysis patients, respectively, one month after completing vaccine schedule with HBV-AS04. HBV-AS02 was superior to licensed vaccine in terms of seroprotection rate, 76.9% vs. 37.6%.

CONCLUSIONS

We suggest adjuvanted recombinant (HBV-AS04) vaccine (0,1,2 and 3 months; 20 mcg each dose) and post vaccination testing of anti-HBs antibody after vaccination. Booster doses to patients whose anti-HBs titers fall below the seroprotection level (<10IU/mL) during the follow-up are appropriate. The patho-physiologic mechanisms responsible for the poor immunogenicity of HBV vaccine in CKD patients are under active investigation.

COVID-19 and Acute Kidney Injury: A Systematic Review and Meta-Analysis

Background: coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome—coronavirus-2 (SARS-CoV-2)—is an ongoing pandemic with high morbidity and mortality rates. Preliminary evidence suggests that acute kidney injury (AKI) is uncommon in patients with COVID-19 and associated with poor outcomes. Study aims and design: we performed a systematic review of the literature with a meta-analysis of clinical studies to evaluate the frequency of AKI and dialysis requirement in patients who underwent hospitalization due to COVID-19. The incidence of AKI according to the death risk was calculated in these patients. The random-effects model of DerSimonian and Laird was adopted, with heterogeneity and stratified analyses. Results: thirty-nine clinical studies (n = 25,566 unique patients) were retrieved. The pooled incidence of AKI was 0.154 (95% CI, 0.107; 0.201; p < 0.0001) across the studies. Significant heterogeneity was found (p = 0.0001). The overall frequency of COVID-19-positive patients who underwent renal replacement therapy (RRT) was 0.043 (95% CI, 0.031; 0.055; p < 0.0001); no publication bias was found (Egger’s test, p = 0.11). The pooled estimate of AKI incidence in patients with severe COVID-19 was 0.53 (95% CI, 0.427; 0.633) and heterogeneity occurred (Q = 621.08, I2 = 97.26, p = 0.0001). According to our meta-regression, age (p < 0.007) and arterial hypertension (p < 0.001) were associated with AKI occurrence in hospitalized COVID-19 positive patients. The odds ratio (OR) for the incidence of AKI in deceased COVID-19 positive patients was greater than among survivors, 15.4 (95% CI, 20.99; 11.4; p < 0.001). Conclusions: AKI is a common complication in hospitalized COVID-19 positive patients. Additional studies are under way to assess the risk of AKI in COVID-19 patients and to deepen the mechanisms of kidney injury.

Adjuvanted recombinant HBV vaccine (HBV-AS04) is effective over extended follow-up in dialysis population. An open-label non randomized trial

BACKGROUND

Patients on regular dialysis show a poor response to hepatitis B vaccine due to uremia. A recombinant HB vaccine (containing an improved adjuvant system AS04, HBV-AS04) has been licensed but the evidence on its efficacy and safety in dialysis population over the long term is extremely limited.

AIM

We have measured antibody (anti-HBs) persistence for up to 72 months in a large cohort of patients on long-term dialysis (with susceptibility to HBV infection) who underwent vaccination with HBV-AS04 vaccine.

METHODS

Patients were prospectively recruited to receive four 20-mcg doses of HBV-AS04 by intramuscular route (deltoid muscle). Two vaccine schedules were adopted: 0,1,2, and 3 month (n=217 patients) and 0,1,2, and 6 month (n=31 patients). Anti-HBs antibody concentrations were tested at 1,2,3, 4, 7 and 12 months and then every year up to 72 months. Multivariate analysis was made to find the baseline parameters that were associated with the immune response to HBV-AS04 vaccine.

RESULTS

Two hundred and seventy-two patients were included and 248 completed the study. At completion of vaccine schedule, the frequency of responders (anti-HBs titers≥10mIU/mL) was 81.5% (202/248) (mean anti-HBs antibody titers, 384.9±391.9mIU/mL), according to per-protocol analysis. On the grounds of univariate analysis, age was lower in responder than non- responder patients to HBV AS04 even if no statistical significance was achieved (P=0.09). The sero-protection rate at month 72 was 77% (7/9) (anti-HBs antibody titers, 184.9±360.1mIU/mL, P=0.001). Multivariate analysis found a relationship between sero-response rate and age (P=0.04). No major side effects and no de novo HBV episodes were observed.

CONCLUSIONS

Our open-label nonrandomized trial performed in a 'real-world' practice showed the persistence of anti-HBs antibody among responder patients over a very long follow-up. Studies with longer observation periods are under way.

Epidemiology of GB Virus C/Hepatitis G Virus Infection in Patients on Peritoneal Dialysis

Background

A new genus in the family Flaviviridae has recently been discovered; it has provisionally been designated GBV-C/HGV. As determined by virologic techniques [reverse-transcription polymerase chain reaction (RT-PCR)], infection with GBV-C/HGV is frequent in renal transplant (RT) recipients and in patients on chronic hemodialysis (HD). The epidemiology of GBV-C/HGV infection in patients on peritoneal dialysis is scarce and mostly based on RT-PCR technology.

Purpose

We report on the prevalence (as detected by serologic and virologic techniques) and the risk factors for GBV-C/HGV infection in a cohort of patients on continuous ambulatory peritoneal dialysis (CAPD). We also tested a control group of blood donors.

Methods

Infection by GBV-C/HGV was assessed by serologic and virologic techniques. Cases of GBV-C/HGV viremia (GBV-C/HGV RNA) were detected by RT-PCR. Antibodies to the envelope protein of GBV-C/HGV (anti-E2 GBV-C/HGV antibody) were analyzed by serologic methods.

Results

We found a high frequency [17/85 (20%)] of GBV-C/HGV. The rates of GBV-C/HGV viremia and anti-E2 GBV-C/HGV positivity were 10.5% (9/85) and 10.5% (9/85) respectively. In most patients [17/18 (94%)], the presence of anti-E2 GBV-C/HGV antibody was associated with clearance of GBV-C/HGV from serum. No relationship was noted between anti-E2 GBV-C/HGV antibody (or GBV-C/HGV viremia) and age, sex, race, time on dialysis, anti-HCV antibody, HBsAg status, and anti-HIV positivity. The frequency of GBV-C/HGV infection in CAPD patients was much higher than that in blood donors, even if the difference did not approach statistical significance. No associations between GBV-C/HGV positivity and biochemical liver tests [aminotransferase and gamma glutamyl transpeptidase (GGT)] were apparent.

Conclusions

Infection by GBV-C/HGV as detected by RT-PCR and anti-E2 antibody was common in patients on CAPD and in controls alike. No association was seen between GBV-C/HGV and various demographic or clinical factors. The clinical significance of GBV-C/HGV in CAPD remains unclear. Larger investigations are in progress.

HBV infection is a risk factor for chronic kidney disease: Systematic review and meta-analysis

BACKGROUND

The activity of hepatitis B virus (HBV) as a risk factor for the incidence and progression of chronic kidney disease (CKD) has not been clarified.

AIM

We evaluated the impact of infection with HBV on the risk of CKD in the general population.

MATERIAL AND METHODS

We carried out a systematic review of the published medical literature to assess whether a relationship between hepatitis B infection and an increased risk of CKD in the adult general population occurs. We adopted the random effects model of DerSimonian and Laird to provide a summary estimate of the risk of chronic kidney disease (defined by lowered glomerular filtration rate and/or detectable proteinuria) with HBV infection across the published studies. Meta-regression and stratified analyses were also performed.

RESULTS

We retrieved 33 studies (n=7,849,849 patients) published in 26 different articles, and separate meta-analyses were performed according to the outcome. Pooling results from cohort studies (11 studies, n=1,056,645 patients) demonstrated a relationship between positive HBV serologic status and increased incidence of CKD, the summary estimate for adjusted HR with HBV across the surveys, 1.40 (95% CI, 1.16-1.69) (P<.001). Between-study heterogeneity was noted (Q value, 49.5, P<.0001). No relationship between HBV and prevalence of CKD was noted in the subset of cross-sectional studies (10 studies; n=3,222,545 patients), adjusted OR, 1.04 (95% IC 0.90-1.218; P=.5). Meta-regression analysis reported a relationship between positive HBsAg status and incidence of CKD in the general population (P<.015).

CONCLUSIONS

It appears that exposure to HBV infection seems to be associated with an increased risk of developing CKD in the adult general population. Studies aimed to understand the mechanisms responsible of such association are under way.

HBV vaccination with Fendrix is effective and safe in pre-dialysis CKD population

BACKGROUND

Patients with chronic kidney disease have a poor response to hepatitis B vaccine due to the immunodeficiency conferred from chronic uremia. A recombinant HB vaccine containing an improved adjuvant system AS04 (HBV-AS04) has been manufactured but scarce evidence exists on HBV-AS04 use among patients with CKD.

AIM

To assess efficacy and safety of an adjuvanted recombinant vaccine (HBV-AS04) in a large cohort of CKD patients at pre-dialysis stage (with susceptibility to HBV infection).

METHODS

Patients were prospectively enrolled to receive four 20-mcg doses of HBV-AS04 by intramuscular route (deltoid muscle) at months 1, 2, 3, and 4. Anti-HBs surface antibody concentrations were tested at intervals of 1, 2, 3, 4, and 12months. Multivariate analyses were performed to assess the parameters, which predicted immunologic response to HBV-AS04 vaccine.

RESULTS

One hundred and seven patients were included and 102 completed the study. At completion of vaccine schedule, the frequency of responders (anti-HBs titers≥10mIU/mL) was 95% (97/102) (mean anti-HBs antibody titers, 688.9±385mIU/mL), according to per-protocol analysis. Serum haemoglobin levels were greater in responder than non- or low-responder patients to HBV-AS04 (P=0.04) and this was confirmed by multivariate analysis. The seroprotection rate at month 50 was 88% (30/34) with lower anti-HBs antibody titers (218.5±269.6mIU/mL, P=0.001). No major side effects were observed.

CONCLUSIONS

Our prospective study performed in a real-world setting showed a high immunogenicity and safety of HBV-AS04 vaccine in patients with CKD not yet on maintenance dialysis. Studies provided with longer follow-ups are under way to assess the durability of seroprotection in responders.

Hepatitis C virus infection and global kidney health: the consensus proceedings of the International Federation of Kidney Foundations

Hepatitis C virus (HCV) infection is an important cause of major morbidities including chronic liver disease, liver cancer, and acute kidney injury (AKI) as well as chronic kidney disease (CKD). HCV can affect kidney health; among CKD and AKI patients with HCV infection, the clinical outcomes are worse. The prevalence of HCV infection is exceptionally high among dialysis and kidney transplant patients throughout the globe. It is estimated that 5% to 25% or more of dialysis dependent patients are affected by chronic HCV, based on the region of the world. Almost half of all deaths in CKD patients, including HCV-infected patients, are due to cardiovascular disease, and HCV infected patients have higher mortality. Given the importance and impact of the HCV epidemic on CKD and global kidney health, and the status of Egypt as the nation with highest prevalence of HCV infection in the world along with its leading initiatives to eradicate HCV, the International Federation of Kidney Foundations (IFKF) convened a consensus conference in Cairo in December 2017. This article reflects the opinions and recommendations of the contributing experts and reiterates that with the current availability of highly effective and well tolerated pharmacotherapy; CKD patients should be given priority for treatment of HCV, as an important step towards the elimination of viral hepatitis as a public health problem by 2030 according to World Health Organization and IFKF. Every country should have an action plan with the goal to improve kidney health and CKD patient outcomes.

Hepatitis C virus infection and global kidney health: the consensus proceedings of the International Federation of Kidney Foundations

Hepatitis C virus (HCV) infection is an important cause of major morbidities including chronic liver disease, liver cancer, acute kidney injury and chronic kidney disease (CKD). Among patients with kidney disease who have HCV infection, the clinical outcomes are worse. The prevalence of HCV infection is exceptionally high among dialysis and kidney transplant patients throughout the globe. It is estimated that 5% to 25% or more of dialysis-dependent patients are affected. Almost half of all deaths in CKD patients, including HCV-infected patients, are due to cardiovascular disease, and HCV-infected patients have higher mortality. Given the importance and impact of the HCV epidemic on global kidney health, and the status of Egypt as the nation with the highest prevalence of HCV infection in the world along with its initiatives to eradicate HCV, the International Federation of Kidney Foundations convened a consensus conference in Cairo in December 2017. This article reflects the opinions and recommendations of the contributing experts and reiterates that, with the current availability of highly effective and well tolerated pharmacotherapy, CKD patients should be given priority for the treatment of HCV, as an important step towards the World Health Organization’s goal of eliminating viral hepatitis as a public health problem by 2030.

HCV-infected solid organ donors, direct-acting antivirals and the current challenges

Introduction: The introduction of direct-acting antiviral therapy has generated tremendous interest in transplanting organs from HCV-infected donors, an option which has the potential to lower waiting times for solid organ transplantation (including kidneys). Safe, effective and pangenotypic direct-acting antiviral agents are currently available.Areas covered: We have identified studies from PubMed, EMBASE, and the Cochrane database to review risks and benefits on solid organ transplantation from HCV-exposed donors in uninfected recipients.Expert opinion: The transmission of HCV with transplantation from anti-HCV positive kidneys without viremia is extremely uncommon whereas recent evidence (five clinical studies, n = 94 patients) shows the absence of HCV infection in HCV-naïve recipients who received kidneys from HCV RNA-positive donors and underwent early DAAs. The evidence regarding non-kidney solid organ transplantation from HCV-infected donors is more limited. One report showed the occurrence of dialysis-dependent kidney failure due to glomerulonephritis induced by acute HCV after liver transplant from a NAT-positive donor into an HCV-naïve recipient. Transplantation of kidneys and other solid organs from HCV-viremic donors into uninfected recipients has the potential to become the standard of care resulting in lower waitlist mortality. Further studies are needed urgently to establish clinical practice guidelines on this topic.

The impact of antiviral therapy for HCV on kidney disease: a systematic review and meta-analysis

BACKGROUND

Controversy persists about the role of hepatitis C as a risk factor for developing kidney disease in the general population. Some authors have evaluated the effect of antiviral therapy for HCV on the risk of kidney disease.

STUDY AIMS AND DESIGN

A systematic review of the published medical literature was performed to assess whether antiviral therapy for HCV has an independent impact on kidney survival in the adult general population. A random effects model was used to generate an overall estimate of the risk of kidney disease after anti-HCV therapy across the published studies. Meta-regression and stratified analysis were also carried out.

RESULTS

Fifteen studies were eligible (n=356, 285 patients) and separate meta-analyses were conducted according to the outcome. Pooling studies based on viral responses (n=7; 34,763 individual patients) demonstrated a relationship between sustained viral response and lower frequency of kidney disease; the overall estimate for adjusted risk of kidney disease was 2.50 (95% CI, 1.41; 4.41) (p=0.0016) and between-study heterogeneity was found (p-value by Q test=0.004). Aggregation of studies comparing treated vs untreated cohorts (n=8, n=333,312 patients) revealed an association between anti-HCV therapy and lower risk of kidney disease. The overall estimate for adjusted risk of kidney disease across the eight studies was 0.39 (95% CI, 0.25; 0.612) (p=0.0001). Meta-regression showed that the effectiveness of antiviral therapy in reducing the frequency of kidney disease diminishes as cirrhosis (p=0.02) and HBV infection (p=0.0001) increase among HCV-infected individuals.

CONCLUSIONS

Antiviral therapy for HCV lowers the risk of kidney disease among HCV-infected individuals. Studies to understand the mechanisms underlying this association are ongoing.

Direct-Acting Antiviral Agents for HCV-Associated Glomerular Disease and the Current Evidence

Glomerular disease is an extra-hepatic manifestation of hepatitis C virus infection (HCV) and membranoproliferative glomerulonephritis is the most frequent glomerular disease associated with HCV. It occurs commonly in patients with HCV-related mixed cryoglobulinemia syndrome. Patients with HCV-related glomerular disease have been historically a difficult-to-treat group. The therapeutic armamentarium for HCV-related glomerular disease now includes antiviral regimens, selective or non-specific immunosuppressive drugs, immunomodulators, and symptomatic agents. The treatment of HCV-associated glomerular disease is dependent on the clinical presentation of the patient. The recent introduction of all-oral, interferon (IFN)-free/ribavirin (RBV)-free regimens is dramatically changing the course of HCV in the general population, and some regimens have been approved for HCV even in patients with advanced chronic kidney disease. According to a systematic review of the medical literature, the evidence concerning the efficacy/safety of direct-acting antiviral agents (DAAs) of HCV-induced glomerular disease is limited. The frequency of sustained virological response was 92.5% (62/67). Full or partial clinical remission was demonstrated in many patients (n = 46, 68.5%) after DAAs. There were no reports of deterioration of kidney function in patients on DAAs. Many patients (n = 29, 43%) underwent immunosuppression while on DAAs. A few cases of new onset or relapsing glomerular disease in patients with HCV successfully treated with DAAs have been observed. In summary, DAA-based combinations are making easier the management of HCV. However, patients with HCV-induced glomerular disease are still a difficult-to-treat group even at the time of DAAs.

Prevention, Diagnosis, Evaluation, and Treatment of Hepatitis C Virus Infection in Chronic Kidney Disease: Synopsis of the Kidney Disease: Improving Global Outcomes 2018 Clinical Practice Guideline

This article has been corrected. The original version (PDF) is appended to this article as a Supplement.

DESCRIPTION

The Kidney Disease: Improving Global Outcomes (KDIGO) 2018 clinical practice guideline for the prevention, diagnosis, evaluation, and treatment of hepatitis C virus (HCV) infection in chronic kidney disease (CKD) is an extensive update of KDIGO's 2008 guideline on HCV infection in CKD. This update reflects the major advances since the introduction of direct-acting antivirals (DAAs) in the management of HCV infection in the CKD population.

METHODS

The KDIGO work group tasked with developing the HCV and CKD guideline defined the scope of the guideline, gathered evidence, determined topics for systematic review, and graded the quality of evidence previously summarized by the evidence review team. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to appraise the quality of evidence and rate the strength of the recommendations. Searches of the English-language literature were conducted through May 2017 and were supplemented with targeted searches for studies of DAA treatment and with abstracts from nephrology, hepatology, and transplantation conferences. A review process involving many stakeholders, subject matter experts, and industry and national organizations informed the guideline's final modification.

RECOMMENDATION

The updated guideline comprises 66 recommendations. This synopsis focuses on 32 key recommendations pertinent to the prevention, diagnosis, treatment, and management of HCV infection in adult CKD populations.

Expert opinion on the management of renal manifestations of chronic HCV infection

Chronic HCV infection is a non-traditional (but modifiable) risk factor for chronic kidney disease and has been implicated in glomerular injury and nephrosclerotic disease. Three HCV direct-acting antiviral regimens are available for patients with severe kidney impairment: ombitasvir, paritaprevir with the pharmacokinetic enhancer ritonavir, and dasabuvir; glecaprevir plus pibrentasvir; and elbasvir plus grazoprevir. In patients with severe kidney impairment, sofosbuvir-free regimens are preferred because sofosbuvir accumulation has been associated with a progressive worsening of renal function. In this Review, we provide our expert opinion on the current HCV treatment paradigm and highlight the remaining issues that need to be overcome to improve the treatment of HCV in this population.

Hepatitis B virus infection as a risk factor for chronic kidney disease

Introduction: Hepatitis B virus is an important cause of liver disease and has numerous extra-hepatic manifestations. HBV leads to important morbidity and mortality in the general population and recent evidence suggests a role of HBV in the incidence and progression of chronic kidney disease. Areas covered: The mechanisms underlying the link between HBV and CKD remain unclear. Nucleos(t)ide analogues for the antiviral treatment of HBV are currently available; these drugs are provided with high efficacy even in patients with CKD. Expert opinion: A recent meta-analysis of clinical studies showed that HBV results in a greater risk of CKD in the general population. According to an updated review (studies were identified from PubMed, EMBASE, and the Cochrane database), we retrieved six clinical studies (n = 1,034,773 unique patients), adjusted RR, 1.41 (95% CI, 1.09; 1.82, P < 0.001). The significant heterogeneity observed precluded more definitive conclusions. Various mechanisms have been cited to explain the greater risk of CKD among HBsAg positive carriers. Novel evidence shows that untreated HBV and therapy with nucleos(t)ide analogues are associated with increased and decreased risk of end-stage renal disease in CKD population, respectively. We recommend that patients with HBV are assessed for kidney function and urinary changes at baseline and over the follow-up.

Executive summary of the 2018 KDIGO Hepatitis C in CKD Guideline: welcoming advances in evaluation and management

Infection with the hepatitis C virus (HCV) has adverse liver, kidney, and cardiovascular consequences in patients with chronic kidney disease (CKD), including those on dialysis therapy and in those with a kidney transplant. Since the publication of the original Kidney Disease: Improving Global Outcomes (KDIGO) HCV Guideline in 2008, major advances in HCV management, particularly with the advent of direct-acting antiviral therapies, have now made the cure of HCV possible in CKD patients. In addition, diagnostic techniques have evolved to enable the noninvasive diagnosis of liver fibrosis. Therefore, the Work Group undertook a comprehensive review and update of the KDIGO HCV in CKD Guideline. This Executive Summary highlights key aspects of the guideline recommendations.

Hepatitis C virus and mortality among patients on dialysis: A systematic review and meta-analysis

BACKGROUND AND RATIONALE

The role of hepatitis C virus (HCV) as an independent risk factor for death in dialysis population is unclear.

DESIGN

A systematic review of the published medical literature was performed to evaluate the impact of positive anti-HCV serologic status on all-cause and disease-specific mortality in patients on regular dialysis. The risk of all-cause, cardiovascular and liver disease-related mortality was regarded as the most reliable outcome end-point. Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates for mortality with HCV across the published studies.

RESULTS

Twenty-three observational studies (n = 574,081 patients on long-term dialysis) were identified. Pooling of study results demonstrated that HCV positive status was an independent and significant risk factor for death in patients on maintenance dialysis. The summary estimate for adjusted death risk (all-cause mortality) with HCV was 1.26 (95% CI: 1.18; 1.34) (P < 0.0001). Between-study heterogeneity was found (Q value 52.8, P = 0.001). The overall estimate for adjusted death risk (liver disease-related mortality) was 5.05 (95% CI: 2.53; 10.0) (P < 0.0001); heterogeneity statistics, Q value 8.2, P = 0.04. The overall estimate for adjusted death risk (cardiovascular mortality) was 1.18 (95% CI: 1.085; 1.29) (P < 0.0001) (no heterogeneity). Meta-regression showed that the effect of HCV on all-cause mortality was more evident in those studies provided with a greater size (P = 0.0001), a higher prevalence of diabetics (P = 0.0005) and HCV-infected individuals (P = 0.001).

CONCLUSIONS

An association between HCV positive serologic status and increased risk of either liver or cardiovascular disease-related mortality exists among dialysis patients.

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.

Impact of hepatitis C virus and direct acting antivirals on kidney recipients: a retrospective study

Hepatitis C virus (HCV) in kidney transplanted patients (KTx-p) carries a high risk for a worse outcome. This retrospective study evaluates the impact of HCV and of the new direct acting antivirals (DAAs) on patient and graft outcomes in KTx patients. Forty (6.5%) of the 616 KTx-p, who received a kidney transplantation (KTx) in our Centre had antibodies against HCV: 13 were positive for HCV RNA and received DAAs (Group A); 11 were HCV RNA positive and did not receive any treatment (Group B; n = 11); 16 were negative for HCV RNA (Group C). All Group A patients had HCV RNA negativity after 12 weeks of treatment, and 12 (92.30%) achieved a sustained virological response (SVR). Only two patients, who had proteinuria greater than 500 mg/day showed a worsening of proteinuria after antiviral therapy in Group A. Liver enzyme elevation and death were significantly more frequent in Group B than other groups. Our results support the notion that active HCV infection negatively affects kidney recipients and that DAA have a high safety and efficacy profile after KTx with no significant negative effect on allograft function, particularly in well-functioning renal grafts.

Hepatitis C virus-induced glomerular disease and posterior reversible encephalopathy syndrome after liver transplant: Case report and literature review

Chronic hepatitis C virus (HCV) infection is associated with numerous extra-hepatic complications, including neurological and renal manifestations. We describe the case of a 67-year-old Caucasian man with HCV-associated cryoglobulinemic glomerulonephritis, cirrhosis, and hepatocellular carcinoma. The early posttransplant course was complicated by fibrosing cholestatic hepatitis due to recurrent HCV in the graft (HCV RNA up to 44,944,438 IU/mL). Proliferative glomerulonephritis (nephritic and nephrotic syndrome) with mixed cryoglobulinemia (purpura) was also recorded. Seventy-two days after surgery, the patient presented with seizures and arterial hypertension; brain magnetic resonance imaging indicated the diagnosis of posterior reversible encephalopathy syndrome (PRES). PRES responded well to medical treatment with complete resolution of neurological changes. Antiviral therapy (sofosbuvir and ribavirin, six months) gave a sustained viral response with the improvement of cryoglobulinemic symptoms (including glomerular disease). Repeat liver biopsy revealed the regression of cholestatic damage and perisinusoidal fibrosis. The current follow-up shows stable chronic renal failure (serum creatinine: 1.4 mg/dL) and mild nephritic syndrome. The impact of extrahepatic manifestations of HCV on patient outcomes is highlighted from novel observational studies reporting a relationship between HCV cure (as expressed by the sustained viral response) and a decrease in both liver-related and renal complications. Clinical trials evaluating the efficacy and tolerance of novel direct-acting antiviral agents for the management of HCV-associated glomerular diseases are underway.

The epidemiology of HCV infection in patients with advanced CKD/ESRD: A global perspective

Liver disease in patients with chronic kidney disease (CKD) is most commonly due to hepatitis C virus (HCV) and contributes to increased rates of mortality. Among the pre-dialysis population, the estimated prevalence of anti-HCV positivity is based on few, limited-size studies. In hemodialysis patients however, HCV remains very prevalent despite large declines in seropositivity rates in dialysis facilities in developed countries after preventive measures were adopted in the 1990s. Recent surveys indicate that the HCV seropositivity prevalence ranges from 1.4%-28.3%, and 4.7%-41.9%, among maintenance dialysis patients in developed and developing countries respectively. Although the full extent of dialysis unit-associated HCV transmission is unknown, outbreaks continue to occur, regardless of health system infrastucture. According to US Centers for Disease Control data, over 50% of health care-associated HCVoutbreaks reported from 2008 to 2015 occurred within dialysis facilities. Strict adherence to infection control procedures and routine serologic screening plays a pivotal role in preventing transmission of HCV within hemodialysis units, even in the setting of low HCV prevalence. With the advent of directly acting antivirals, cure of HCV-infected patients on maintenance hemodialysis will help reduce transmission within units and further lower the frequency of HCV infection.

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.

Managing hepatitis C therapy failures and chronic kidney disease

INTRODUCTION

Hepatitis C virus (HCV) infection leads to important morbidity and mortality through liver disease and extra-hepatic manifestations. Recent evidence suggests the role of HCV in developing chronic kidney disease (CKD); also, HCV adversely affects cardiovascular (CV) disease both in the general population and in patients with CKD. Areas covered: All-oral, interferon-free direct-acting antiviral agents (DAAs) are currently available; anti-HCV regimens based on DAAs are provided with high efficacy and safety and short treatment duration. However, some difficult-to-treat populations still exist including patients with CKD and those who failed previous DAA regimen. Expert commentary: Two DAAs regimens (elbasvir/grazoprevir and glecaprevir/pibrentasvir) are now recommended for the treatment of HCV in patients with advanced CKD, these combinations have shown great efficacy, according to two multicenter phase-3 trials (C-SURFER and EXPEDITION-4). These trials reported a minimal impact of baseline resistance-associated substitutions (RASs) on treatment outcomes. The sofosbuvir/velpatasvir/voxaliprevir combination has been recommended as the first-line option for DAAs failures, on the basis of the results given by two randomized clinical trials involving patients who had been previously received DAA-containing regimens (POLARIS 1-4 studies). It has been suggested that clinicians should consider RASs upon the introduction of DAA-based antiviral therapy.

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.

[Direct-acting antiviral agents, hepatitis C and dialysis: an update]

Hepatitis C virus infection is still common among patients with chronic kidney disease, particularly within Dialysis Units all over the world. Although the full extent of HCV transmission in dialysis units is unknown, outbreaks of HCV infection continue to occur all over the world. Evidence has been accumulated in the last decade suggesting that HCV plays consistent activity at hepatic and extra-hepatic level. A recent systematic review of the medical literature with a meta-analysis of clinical studies retrieved 15 longitudinal studies (n=2,299,134 patients) ; we found a significant relationship between anti-HCV positive serologic status and higher frequency of CKD; the summary estimate for adjusted hazard risk with HCV across the surveys, 1.54 (95% CI, 1.26; 1.87) (P<0.0001). The advent of direct-acting antiviral agents has revolutionized the therapy of HCV, including patients with advanced chronic kidney disease. Two regimens based on DAAs have been recently approved for the antiviral therapy of HCV in patients with CKD stage 4/5: elbasvir/grazoprevir and glecaprevir/pibrentasvir. Such regimens have been provided with high efficacy and safety, according to the results given by C-SURFER and EXPEDITION-4, respectively. Sofosbuvir, a non-structural 5B polymerase inhibitor, is the backbone of many anti-HCV drug regimens, and has significant renal excretion. As a result, the use of sofosbuvir is not recommended in patients with an eGFR <30 mL/min/1.73m². In summary, recent studies have shown that several combinations of DAAs are currently available for CKD patients, including those with CKD stage 4/5. These drugs have reported high efficacy and satisfactory tolerability, regardless of HCV genotype or renal impairment. We need to improve the screening for HCV and the access to DAAs in patients with CKD stage 4/5.

Chronic Kidney Disease after Liver Transplantation: Recent Evidence

Chronic kidney disease is a common complication after liver transplantation with an incidence ranging between 20% and 80%. Studies of renal function after liver transplantation have yielded conflicting results: the wide range in incidence rates of chronic kidney disease (CKD) following liver transplantation is related to the methods for measuring kidney function, and various criteria for defining renal dysfunction, among others. An important cause of CKD among liver transplant recipients is calcineurin inhibitor-based immunosuppression. Additional predictors of CKD post-liver transplantation include pre-transplant kidney function, peri-operative acute kidney failure, age, and hepatitis C. A recent meta-analysis of observational studies revealed that, in the subgroup of studies provided with glomerular filtration rate at baseline, the summary estimate of relative risk and 95% confidence intervals (CI) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01–4.46, p=0.047). Acute renal insufficiency is common immediately after liver transplantation, whereas the course of CKD after liver transplantation appears progressive over time. Only preliminary information exists on kidney pathological findings in recipients of liver transplants with CKD. Introduction of the Model for End-stage Liver Disease for the allocation of liver grafts has not increased the occurrence of renal dysfunction following liver transplantation. Chronic kidney disease following liver transplantation increases cardiovascular burden dramatically. The use of mycophenolic acid- or sirolimus-based immunosuppression in calcineurin-inhibitors sparing protocols is an area of intense research.

Immunosuppressive and antiviral treatment of hepatitis C virus-associated glomerular disease: A long-term follow-up

BACKGROUND

The evidence in the medical literature on the treatment of hepatitis C virus-associated glomerular disease is extremely limited. The advent of nonconventional immunosuppressive agents and direct-acting antivirals promises high efficacy and safety.

AIMS

We conducted an open-label, single-arm clinical study to examine the efficacy and safety of a combined approach for hepatitis C virus-associated glomerular disease.

METHODS

In the first phase of the study, patients with hepatitis C virus-associated glomerular disease received interferon-based antiviral therapy and immunosuppressive agents; since 2013, interferon-free antiviral therapy was adopted and novel immunosuppressants (including B-cell depleting agents and mycophenolate mofetil) or immunomodulators (ribavirin) were choiced. Virological and clinical responses were evaluated over a long observation period (median follow-up of 60 weeks and 46.5 months after the end of treatment with interferon and direct-acting antiviral agents, respectively).

RESULTS

We enrolled 25 consecutive patients with hepatitis C virus-associated glomerular disease, 8 being liver transplant recipients for hepatitis C. A total of 13 patients received therapy with direct-acting antivirals and experienced sustained viral response (serum hepatitis C virus RNA <12 IU/mL, 12 weeks after treatment ended, sustained viral response12). The mean (±standard deviation) proteinuria decreased from 2.61 ± 1.01 at baseline to 1.71 ± 1.43 (g/day) at sustained viral response 48, p = 0.031; microscopic hematuria and serum cryoglobulins disappeared in six (50%) and seven (64%) patients, respectively, after sustained viral response by direct-acting antivirals. Adverse events occurred in 69% (9/13) of patients and were mild, with four cases of ribavirin-related anemia requiring blood transfusions (no drop-outs). After sustained viral response by direct-acting antivirals, immunosuppressive and immunomodulatory agents were initiated in clinical relapsers ( n = 2) and nonresponders ( n = 3) with some benefit. Among patients on interferon-based regimens ( n = 12), viral response (sustained viral response 24) and dropout rates were 58% (7/12) and 33% (4/12), respectively. After sustained viral response by interferon-based therapy, clinical relapsers ( n = 3) were successfully managed with immunosuppressive agents in two patients.

CONCLUSION

Treatment with direct-acting antivirals provides excellent rates of viral response and safety in patients with hepatitis C virus-related glomerular disease; viral response was frequently accompanied by clinical improvement. The absence of hepatitis C virus RNA from serum allowed immunosuppressive and immunomodulatory therapies with benefits for glomerular abnormalities and no concern on hepatitis C virus replication.

'Real-life' experience with direct-acting antiviral agents for hepatitis C virus in end-stage renal disease

BACKGROUND AND AIMS

The advent of direct-acting antiviral agents promises to change the management of hepatitis C in patients with end-stage renal disease, a patient group where the treatment of hepatitis C was historically challenging. We investigated the safety and efficacy of all-oral, interferon-free direct-acting antiviral agents for the treatment of hepatitis C in a 'real-world' group of patients with end-stage renal disease.

METHODS

We performed a single-arm, multi-centre study in a cohort (n=30) of patients with advanced chronic kidney disease (mostly on dialysis) who underwent antiviral therapy with direct-acting antiviral agents. The primary end-point was sustained virologic response (serum hepatitis C virus RNA < 15 mIU/mL, 12 weeks after treatment ended). We collected data on on-treatment adverse events, serious adverse events and laboratory abnormalities.

RESULTS

In total, 23 (77%) and 7 (23%) patients underwent regular dialysis and had chronic kidney disease at pre-dialysis stage, respectively. Six regimens were adopted: elbasvir/grazoprevir ( n = 6), ledipasvir/sofosbuvir ± ribavirin ( n = 4), PrOD regimens ± ribavirin ( n = 10), simeprevir + daclatasvir ( n = 3), sofosbuvir + daclatasvir ± ribavirin ( n = 3), sofosbuvir + ribavirin ( n = 4). The SVR12 rate was 90% (95% confidence interval, 74%; 96%). A total of 27 (90%) patients achieved SVR12; there were three virologic failures - two were non-responders and one had a viral breakthrough while on therapy. Adverse events occurred in 53% (16/30) (95% confidence interval, 0.39; 0.73) of patients and were managed clinically without discontinuation of therapy or hospitalization. The most common adverse event was anaemia ( n = 12) that required blood transfusions in seven individuals; deterioration of kidney function occurred in one (14%).

CONCLUSION

All-oral, interferon-free therapy with direct-acting antiviral agents for chronic hepatitis C virus in advanced chronic kidney disease was effective and well tolerated in a 'real-life' clinical setting. Careful monitoring of haemoglobin and serum creatinine during therapy with direct-acting antiviral agents is suggested. Studies are under way to address whether sustained viral response translates into better survival in this population.

Therapy with Nucleos(t)ide Analogues: Current Role in Dialysis Patients

Hepatitis B virus (HBV) infection persists among patients undergoing maintenance dialysis in the industrialized world. Knowledge of the epidemiology and the natural history of HBV infection in dialysis patients has markedly improved but antiviral therapy for hepatitis B remains a significant challenge in this population. A variety of therapeutic options are now available for the treatment of chronic hepatitis B, including potent new nucleos(t)ide analogues, along with standard and pegylated interferon. The most extensive experience in the dialysis population has been with lamivudine. Although several questions about lamivudine use in dialysis patients remain unanswered, it has shown potent antiviral activity: the range of clearance of HBV viremia (HBV DNA) from serum is between 56% and 100% in dialysis patients with chronic hepatitis B. Its major limitation is emergence of resistance. Tolerance to conventional or pegylated interferon monotherapy is poor in the dialysis population. There is limited data regarding adefovir dipivoxil (ADV) therapy in the dialysis population, while very little information is available about the use of the newer agents, tenofovir and entecavir, in patients with renal failure. It is recommended that dialysis patients with persistent HBsAg seropositive status be evaluated for antiviral treatment and that the decision to treat be based on the potential benefits and risks of therapy including life expectancy, candidacy for kidney transplantation, and comorbidities. Hepatitis B is relatively uncommon among patients undergoing dialysis in developed countries and this clearly hampers prospective clinical trials aimed to evaluate the efficacy and safety of therapy with nucleos(t)ide analogues for chronic hepatitis B in this population.