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.

The Impact of Antiviral Treatment of Hepatitis B Virus after Kidney Transplant and the Latest Insights.

BACKGROUND: The current frequency of hepatitis B virus infection in patients with advanced chronic kidney disease (CKD) (including patients on maintenance dialysis and kidney transplant recipients) is low but not negligible worldwide. HBV has a deleterious effect on survival after a kidney transplant; antiviral treatments improved the short-term outcomes of kidney transplant recipients, but their long-term impact remains uncertain. AIM: The aim of this review is to assess the role of antiviral therapy for HBV in improving survival after a kidney transplant. The recent publication of large surveys has prompted us to update the available evidence on the impact of HBV on patient and graft survival after a kidney transplant. METHODS: We have conducted an extensive review of the medical literature, and various research engines have been used. RESULTS: We retrieved several studies (n = 11; n = 121,436 unique patients) and found an association between positive serologic HBsAg status and diminished patient and graft survival after a kidney transplant; the adjusted relative risk (aRR) of all-cause mortality and graft loss was 2.85 (95% CI, 2.36; 3.33, p < 0.0001) and 1.26 (95% CI, 1.02; 1.51, p < 0.0001), respectively. To our knowledge, at least six studies reported improved patient and graft survival after the adoption of antiviral therapies for HBV (this result was reported with both survival curves and multivariable regression). According to novel clinical guidelines, entecavir has been suggested as a 'first line' antiviral agent for the treatment of HBV after a kidney transplant. CONCLUSIONS: The recent availability of safe and effective antiviral drugs for the treatment of HBV has meant that the survival curves of HBsAg-positive patients on antiviral therapy and HBsAg-negative patients after a kidney transplant can be comparable. Antiviral therapy should be systematically proposed to HBV-positive kidney transplant recipients and candidates to avoid the deleterious hepatic and extra-hepatic effects of chronic HBV replication.

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.

Recent Information on Pan-Genotypic Direct-Acting Antiviral Agents for HCV in Chronic Kidney Disease.

BACKGROUND: Hepatitis C virus (HCV) is still common in patients with chronic kidney disease. It has been recently discovered that chronic HCV is a risk factor for increased incidence of CKD in the adult general population. According to a systematic review with a meta-analysis of clinical studies, pooling results of longitudinal 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 across the surveys was 1.54 (95% CI, 1.26; 1.87), (p < 0.0001). The introduction of direct-acting antiviral drugs (DAAs) has caused a paradigm shift in the management of HCV infection; recent guidelines recommend pan-genotypic drugs (i.e., drugs effective on all HCV genotypes) as the first-choice therapy for HCV, and these promise to be effective and safe even in the context of chronic kidney disease. AIM: The purpose of this narrative review is to show the most important data on pan-genotypic DAAs in advanced CKD (CKD stage 4/5). METHODS: We recruited studies by electronic databases and grey literature. Numerous key-words ('Hepatitis C' AND 'Chronic kidney disease' AND 'Pan-genotypic agents', among others) were adopted. RESULTS: The most important pan-genotypic combinations for HCV in advanced CKD are glecaprevir/pibrentasvir (GLE/PIB) and sofosbuvir/velpatasvir (SOF/VEL). Two clinical trials (EXPEDITION-4 and EXPEDITION-5) and some 'real-world' studies (n = 6) reported that GLE/PIB combinations in CKD stage 4/5 gave SVR12 rates ranging between 86 and 99%. We retrieved clinical trials (n = 1) and 'real life' studies (n = 6) showing the performance of SOF/VEL; according to our pooled analysis, the summary estimate of SVR rate was 100% in studies adopting SOF/VEL antiviral combinations. The drop-out rate (due to AEs) in patients on SOF/VEL ranged between 0 and 4.8%. CONCLUSIONS: Pan-genotypic combinations, such as GLE/PIB and SOF/VEL, appear effective and safe for HCV in advanced CKD, even if a limited number of studies with small sample sizes currently exist on this issue. Studies are under way to assess whether successful antiviral therapy with DAAs will translate into better survival in patients with advanced CKD.

Acute Kidney Injury in Non-Intensive Care Unit (ICU) Hospitalizations for Coronavirus Disease (COVID-19).

Background: Acute kidney injury (AKI) is a common complication among SARS-CoV-2-positive patients who undergo hospitalization. Abundant evidence exists concerning the epidemiology of AKI in patients hospitalized in the ICU for COVID-19 but limited data are available about the occurrence of AKI in SARS-CoV-2-positive patients being hospitalized in a non-ICU setting. Aim and Methods: We have carried out a retrospective study to evaluate frequency and risk factors for AKI among patients consecutively admitted at a third-level university hospital starting from February 2020 (the beginning of the first wave of the SARS-CoV-2 pandemic); all patients were hospitalized outside the ICU. Results: A total of 387 SARS-CoV-2-positive patients were included in the current study; 372 (96.1%) had SARS-CoV-2-related pneumonia. In-hospital AKI onset was recorded in 119 (30.7%) patients, mainly with AKI stage 1 (n = 74, 62.2%); eighteen (4.6%) patients reported AKI stage 3 and six (1.5%) patients had HD-dependent AKI. There were 235 (60.7%) patients with severe COVID-19, and this was more common in patients developing AKI, 94.5% (86/119) vs. 86.1% (149/268), p = 0.02. Multivariate regression model (n = 144 patients) reported an independent and significant relationship between AKI occurrence and greater levels of ferritin (p = 0.036), IL-6 (p = 0.032), and azotemia at admission (p = 0.0001). A total of 69 (17.8%) SARS-CoV-2-positive patients died and strong predictors of in-hospital death resulted from age (p < 0.0001), serum ferritin (p < 0.0001) and white blood cells (p < 0.001). According to multivariable analysis (n = 163 patients), there was a consistent link between in-hospital death and AKI stage (1) (p = 0.021) and -stage (2) (p = 0.009). Our results support the notion that AKI occurs frequently among hospitalized COVID-19 patients even in a non-ICU setting and plays a pivotal role in the mortality of this population. Further studies are ongoing in order to clearly establish the frequency of AKI in patients with COVID-19; the mechanisms underlying kidney injury in this population are an area of active investigation. These data provide solid evidence to support close monitoring of COVID-19 patients for the development of AKI and measures taken to prevent this.

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.

Prevalence and Risk Factors for Anti-SARS-CoV-2 Antibody in Chronic Kidney Disease (Dialysis Independent and Not).

Background: The evidence in the medical literature regarding the prevalence of antibody towards SARS-CoV-2 in patients with chronic kidney disease is limited, particularly among those at the pre-dialysis stage. Aim: We have prospectively performed a cohort study at a third-level university hospital to evaluate frequency and risk factors for anti-SARS-CoV-2-positive serology among chronic kidney disease patients. Methods: We have tested a cohort of consecutive outpatients with chronic kidney disease on regular follow-up at a major metropolitan hospital, during the SARS-CoV-2 outbreak in Italy. We adopted an enzyme immunoassay for the assessment of IgM/IgG antibodies to SARS-CoV-2 in human serum or plasma (DIA.PRO COVID-19 Serological Assay); the assay detects antibodies against Spike (1/2) and Nucleocapsid proteins of the SARS-CoV-2 genome. Results: There were 199 (65.8%) out of 302 patients with dialysis-independent CKD; 2 patients were anti-SARS-CoV-2 IgM antibody positive, 23 were anti-SARS-CoV-2 IgM/IgG positive and 37 had detectable anti-SARS-CoV-2 IgG antibody in serum. The prevalence of anti-SARS-CoV-2 IgG was 20.5% (60/302). All patients positive for anti-SARS-CoV-2 antibody tested negative by nasopharyngeal swab. A significant and independent relationship between anti-SARS-CoV-2-positive serologic status and serum albumin (a marker of nutritional status) was observed (p < 0.046). The prevalence of anti-SARS-CoV-2 antibody was greater in CKD than in control populations (health care workers and blood donors) attending the hospital a few months before the current study (7.6% and 5.2%, respectively). Conclusions: The great prevalence of anti-SARS-CoV-2 antibody in our study group could be, at least partially, explained with the fact that our patients were living in Milan, an area severely hit by SARS-CoV-2 infection. It seems that a poor nutritional status supports the acquisition of SARS-CoV-2 antibody in CKD patients. Clinical studies to understand the mechanisms responsible for the high frequency of SARS-CoV-2 infection are under way.

Acute kidney injury and chronic kidney disease after liver transplant: A retrospective observational study / Lesión renal aguda y enfermedad renal crónica después de trasplante hepático. Un estudio observacional retrospectivo

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 methodsWe 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).ResultsWe 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.ConclusionThe 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. ... (AU)

Antecedentes y justificación: La enfermedad renal crónica (ERC) sigue siendo un importante factor de riesgo de morbimortalidad entre los receptores de un trasplante hepático (TH), su incidencia exacta y sus factores de riesgo aún no están claros.Materiales y métodosLlevamos a cabo un estudio de cohortes retrospectivo de adultos incluidos de forma consecutiva que habían recibido un TH (de enero de 2009 a diciembre de 2018) e hicimos el seguimiento (mínimo 6 meses) en nuestra institución. La ERC se definió siguiendo las guías de práctica clínica Kidney Disease: Improving Global Outcomes (KDIGO) de 2012. La función renal a largo plazo se clasificó en 4 grupos: sin ERC (filtración glomerular estimada [FGe]>60ml/min/1,73m2), ERC leve (FGe: 30-59ml/min/1,73m2), ERC grave (FGe: 15-29ml/min/1,73m2) y enfermedad renal terminal (ERT).ResultadosIncluimos a 410 pacientes a los que se hizo un seguimiento durante 53,2±32,6 meses: 39 tenían ERC al inicio y 95 desarrollaron ERC de novo durante el periodo de observación. Había 184 (44,9%) receptores con anticuerpos contra el VHC, 47 (11,5%) con positividad para el HBsAg y 33 (8,1%) portadores del virus de la hepatitis B (VHB) o el virus de la hepatitis D (VHD). Los factores de riesgo de los receptores para presentar ERC al inicio fueron la edad avanzada (p=0,044), unos niveles elevados de ácido úrico en suero (p<0,0001) y la presencia de diabetes mellitus (DM) insulinodependiente (p=0,0034). La aparición temprana de lesión renal aguda (LRA) postrasplante fue frecuente (n=95); un análisis de regresión logística reveló que la creatinina sérica al inicio era un factor predictivo independiente de LRA temprana después del TH (p=0,0154). Según nuestro modelo de riesgos proporcionales de Cox, los factores de riesgo de los receptores para presentar ERC de novo incluyeron la edad avanzada (p<0,0001), una LRA temprana postrasplante (p=0,007) y la creatinina sérica al inicio (p=0,0002). ...

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.

Sofosbuvir-based regimens for HCV in stage 4–stage 5 chronic kidney disease. A systematic review with meta-analysis / Tratamientos basados en sofosbuvir en la infección por el VHC en la enfermedad renal crónica en estadio 4 o estadio 5. Una revisión sistemática con metaanálisis

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. (AU)

Antecedentes: La hepatitis C es un importante agente de daño hepático en los pacientes con enfermedad renal crónica. La aparición de los antivíricos de acción directa (AAD) ha cambiado espectacularmente el tratamiento de los pacientes con positividad para el virus de hepatitis C (VHC), incluidos los que presentan enfermedad renal crónica (ERC) avanzada. El sofosbuvir es la piedra angular de muchos tratamientos contra la infección por el VHC basados en AAD, pero sigue habiendo dudas sobre si es apropiado en los pacientes con infección por el VHC y ERC en estadio 4-5. Objetivos y diseño del estudio: Realizamos una revisión sistemática de la literatura médica con un metaanálisis de estudios clínicos para evaluar la eficacia y la seguridad de tratamientos con AAD basados en el sofosbuvir en pacientes con ERC en estadio 4-5. El criterio principal de valoración fue la respuesta virológica sostenida (como indicador de la eficacia); los criterios secundarios de valoración fueron la frecuencia de acontecimientos adversos graves (AAG) y los abandonos por acontecimientos adversos (AA) (como indicadores de la tolerabilidad). Se adoptó el modelo de efectos aleatorios de DerSimonian y Laird, con análisis estratificados y de heterogeneidad. (AU)

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.

An Update on Hepatocellular Carcinoma in Chronic Kidney Disease.

Chronic kidney disease is a major public health issue globally and the risk of cancer (including HCC) is greater in patients on long-term dialysis and kidney transplant compared with the general population. According to an international study on 831,804 patients on long-term dialysis, the standardized incidence ratio for liver cancer was 1.2 (95% CI, 1.0-1.4) and 1.5 (95% CI, 1.3-1.7) in European and USA cohorts, respectively. It appears that important predictors of HCC in dialysis population are hepatotropic viruses (HBV and HCV) and cirrhosis. 1-, 3-, and 5-year survival rates are lower in HCC patients on long-term dialysis than those with HCC and intact kidneys. NAFLD is a metabolic disease with increasing prevalence worldwide and recent evidence shows that it is an important cause of liver-related and extra liver-related diseases (including HCC and CKD, respectively). Some longitudinal studies have shown that patients with chronic hepatitis B are aging and the frequency of comorbidities (such as HCC and CKD) is increasing over time in these patients; it has been suggested to connect these patients to an appropriate care earlier. Antiviral therapy of HBV and HCV plays a pivotal role in the management of HCC in CKD and some combinations of DAAs (elbasvir/grazoprevir, glecaprevir/pibrentasvir, sofosbuvir-based regimens) are now available for HCV positive patients and advanced chronic kidney disease. The interventional management of HCC includes liver resection. Some ablative techniques have been suggested for HCC in CKD patients who are not appropriate candidates to surgery. Transcatheter arterial chemoembolization has been proposed for HCC in patients who are not candidates to liver surgery due to comorbidities. The gold standard for early-stage HCC in patients with chronic liver disease and/or cirrhosis is still liver transplant.

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 chronic kidney disease (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 supports this approach. Novel data support the notion that sustained viral response with anti-HCV regimens leads to improvement of hepatic and extrahepatic outcomes. A systematic review with meta-analysis 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.

Updated View on Kidney Transplant from HCV-Infected Donors and DAAs.

BACKGROUND: The discrepancy between the number of potential available kidneys and the number of patients listed for kidney transplant continues to widen all over the world. The transplant of kidneys from hepatitis C virus (HCV)-infected donors into HCV naïve recipients has grown recently because of persistent kidney shortage and the availability of direct-acting antiviral agents. This strategy has the potential to reduce both waiting times for transplant and the risk of mortality in dialysis. AIM: We made an extensive review of the scientific literature in order to review the efficacy and safety of kidney transplant from HCV-viremic donors into HCV naïve recipients who received early antiviral therapy with direct-acting antiviral agents (DAAs). RESULTS: Evidence has been rapidly accumulated on this topic and some reports have been published (n = 11 studies, n = 201 patients) over the last three years. Various combinations of DAAs were administered-elbasvir/grazoprevir (n = 38), glecaprevir/pibrentasvir (n = 110), and sofosbuvir-based regimens (n = 53). DAAs were initiated in a range between a few hours before renal transplant (RT) to a median of 76 days after RT. The sustained virological response (SVR) rate was between 97.5% and 100%. A few severe adverse events (SAEs) were noted including fibrosing cholestatic hepatitis (n = 3), raised serum aminotransferase levels (n = 11), and acute rejection (n = 7). It remains unclear whether the AEs were related to the transmission of HCV, the use of DAAs, or kidney transplant per se. It appears that the frequency of AEs was greater in those studies where DAAs were not given in the very early post-kidney transplant phase. CONCLUSIONS: The evidence gathered to date encourages the expansion of the kidney donor pool with the adoption of HCV-infected donor organs. We suggest that kidney transplants from HCV-viremic kidneys into HCV-uninfected recipients should be made in the context of research protocols. Many of the studies reported above were externally funded and we need research generating "real-world" evidence. The recent availability of pangenotypic combinations of DAAs, which can be given even in patients with eGFR < 30/min/1.73 m2, will promote the notion that HCV-viremic donors are a significant resource for kidney transplant.

Hepatitis B virus vaccine and chronic kidney disease. The advances / Vacuna contra el virus de la hepatitis B y la nefropatía crónica: avances

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; 40 mcg 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 (< 10 IU/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

ANTECEDENTES: La hepatitis B es un importante agente de la enfermedad hepática en pacientes con nefropatía crónica (NC) y la infección crónica por el virus de la hepatitis B (VHB), promueve el desarrollo de la NC en la población general adulta. Los pacientes con NC tienen una respuesta subóptima a varias vacunas, y no está claro cómo podemos aumentar la respuesta inmunológica de estos pacientes a la vacuna contra el VHB. Objetivos y diseño del estudio: Realizamos una revisión narrativa para evaluar los mecanismos de menor inmunogenicidad de la vacuna contra el VHB en la población con NC; se han documentado varios enfoques para mejorar la tasa de respuesta de los pacientes con NC a la vacuna contra el VHB. Este es un tema muy importante para los nefrólogos, que a menudo atienden como médicos de atención primaria a pacientes con NC. RESULTADOS: El programa de vacunación recomendado para los pacientes con NC, incluidos los que están en diálisis de mantenimiento, se basa en una vacuna recombinante de cuatro dosis (meses 0, 1, 2 y 6; 40 mcg cada dosis), administrada por vía intramuscular (músculo deltoides). Según los ECA, o estudios observacionales, algunas vacunas recombinantes con adyuvantes (es decir, HBV-AS02 y HBV-AS04) parecen prometedoras. La HBV-AS04 demostró ofrecer mejores tasas de seroprotección y una respuesta inmunitaria duradera durante los seguimientos prolongados, en comparación con la vacuna autorizada contra el VHB en pacientes con NC. La tasa de seroprotección fue del 95% (97/102) y del 82% (202/248), en pacientes en prediálisis y diálisis, respectivamente, un mes después de completar el programa de vacunación con HBV-AS04. La HBV-AS02 fue superior a la vacuna autorizada con respecto a la tasa de seroprotección, 76,9 vs. a 37,6%. CONCLUSIONES: Sugerimos una vacuna recombinante con adyuvante (HBV-AS04) (meses 0, 1, 2 y 3, 20 mcg cada dosis) y pruebas de anticuerpos anti-HB después de la vacunación. Se consideran adecuadas las dosis de refuerzo para los pacientes cuyos títulos de anticuerpos anti-HB sean inferiores al nivel de seroprotección (< 10 UI/mL) durante el seguimiento. Los mecanismos fisiopatológicos responsables de una inmunogenicidad deficiente de la vacuna contra el VHB en pacientes con NC son objeto de investigaciones exhaustivas

'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.

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.

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.