Effect of HBV polymerase inhibitors on renal function in patients with chronic hepatitis B

Effect of pegylated interferon-α2b add-on therapy on renal function in chronic hepatitis B patients: A real-world experience

Background and aim

Controversy remains as to pegylated interferon-α (PEG-IFNα) antiviral therapy to renal function in chronic hepatitis B (CHB) patients. The aim of this study was to evaluate the influence of PEG-IFNα2b (Y shape, 40 kD) add-on treatment for renal function in CHB patients who received entecavir therapy.

Methods

This was a retrospective observational study to investigate factors related to renal function in 114 CHB patients who received PEG-IFNα2b add-on therapy to entecavir for 48 weeks. Changes of blood urea nitrogen (BUN), serum creatinine (sCr), and estimated glomerular filtration rate (eGFR), which was calculated with both Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease (MDRD) formulas, were analyzed by one-way analysis of variance. A linear mixed effects model for repeated measures was used to assess the correlation between baseline information and eGFR changes at 24 and 48 weeks of therapy. The model considered the baseline age, gender, body weight, viral load, hepatitis B surface antigen, BUN, sCr, and treatment strategy as fixed effects and incorporated random effects for individual subjects.

Results

BUN and sCr was decreased, while eGFR was increased at 12 weeks of therapy. Only eGFR maintained at 24 and 48 weeks of therapy. Patients with female gender, age ≥ 40 years, and baseline HBsAg level < 250 IU/mL showed significant improvement of renal function with PEG-IFNα2b add-on therapy. The linear mixed effects model revealed that female gender, baseline sCr, and PEG-IFNα2b add-on were significant positive predictors for eGFR elevation at 24 and 48 weeks of therapy.

Conclusion

In real-world experience, PEG-IFNα2b add-on therapy might be associated with increased eGFR in CHB patients.

Renal safety of tenofovir disoproxil fumarate and entecavir in liver transplant patients: a nationwide Korean registry study

BACKGROUND AND AIMS

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) have been recommended after liver transplantation to prevent recurrence of hepatitis B virus infection. Despite its proven efficacy, the renal safety of TDF has not been established in liver transplant recipients. We aimed to compare the effects of TDF and ETV on renal function in liver transplant recipients and to evaluate risk factors for renal dysfunction after liver transplantation.

METHODS

This is a retrospective, observational multicenter study of data from the Korean Organ Transplantation Registry. We included adults who underwent liver transplantation for hepatitis B virus-related complications from April 2014 to December 2017 and received TDF or ETV post-transplantation. Renal dysfunction was defined as an estimated glomerular filtration rate decline by at least 20% from baseline (1 month post-transplantation). Median duration of follow-up was 29 months (interquartile range 19-42).

RESULTS

A total of 804 liver transplant patients were included. The cumulative probability of renal dysfunction was significantly higher in the TDF group than in the ETV group. Multivariable analysis confirmed that TDF was independently associated with an increased risk of renal dysfunction (hazard ratio = 1.47, 95% confidence interval 1.12-1.92; p = 0.005). Independent risk factors for renal dysfunction included older age, worse baseline renal function, and low body mass index. Overall survival rate was significantly lower in patients with renal dysfunction than in those without.

CONCLUSIONS

In this nationwide study, the use of TDF was associated with an increased risk of renal dysfunction, when compared with ETV.

Longitudinal renal changes in chronic hepatitis B patients treated with entecavir versus TDF: a REAL-B study

BACKGROUND AND AIMS

We aimed to compare the longitudinal changes in estimated glomerular filtration rate (eGFR) in chronic hepatitis B (CHB) patients treated with entecavir (ETV) vs. tenofovir disoproxil fumarate (TDF).

METHODS

This is a retrospective study of 6189 adult treatment-naïve CHB patients initiated therapy with TDF (n = 2482) or ETV (n = 3707) at 25 international centers using multivariable generalized linear modeling (GLM) to determine mean eGFR (mL/min/1.73 m²) and Kaplan-Meier method to estimate incidence of renal impairment (≥ 1 chronic kidney disease [CKD] stage worsening). We also examined above renal changes in matched ETV and TDF patients (via propensity score matching [PSM] on age, sex, diabetes mellitus [DM], hypertension [HTN], cirrhosis, baseline eGFR, and follow-up duration).

RESULTS

In the overall cohort (mean age 49.7 years, 66.2% male), the baseline eGFR was higher for TDF vs. ETV group (75.9 vs. 74.0, p = 0.009). PSM yielded 1871 pairs of ETV or TDF patients with baseline eGFR ≥ 60 and 520 pairs for the eGFR < 60 group. GLM analysis of the overall (unmatched) cohort and PSM cohorts revealed lower adjusted mean eGFRs in TDF (vs. ETV) patients (all p < 0.01) during 10 years of follow-up. Among PSM eGFR ≥ 60 patients, the 5-year cumulative incidences of renal impairment were 42.64% for ETV and 48.03% for TDF (p = 0.0023). In multivariable Cox regression, TDF vs. ETV (adjusted HR 1.26, 95% CI 1.11-1.43) was associated with higher risk of worsening renal function.

CONCLUSION

Over the 10-year study follow-up, compared to ETV, TDF was associated with a lower mean eGFR and higher incidence of renal impairment.

Tenofovir Alafenamide Rescues Renal Tubules in Patients with Chronic Hepatitis B

Nucles(t)ide analogs (NAs) are effective for chronic hepatitis B (CHB). NAs suppress hepatic decompensation and hepatocarcinogenesis, leading to a dramatic improvement of the natural course of patients with CHB. However, renal dysfunction is becoming an important issue for the management of CHB. Renal dysfunction develops in patients with the long-term treatment of NAs including adefovir dipivoxil and tenofovir disoproxil fumarate. Recently, several studies have reported that the newly approved tenofovir alafenamide (TAF) has a safe profile for the kidney due to greater plasma stability. In this mini-review, we discuss the effectiveness of switching to TAF for NAs-related renal tubular dysfunction in patients with CHB.

High level of medication adherence is required to lower mortality in patients with chronic hepatitis B taking entecavir: A nationwide cohort study

It is unclear whether suboptimal adherence contributes to adverse clinical outcomes in patients with chronic hepatitis B (CHB). Moreover, there is no consensus regarding the optimal level of drug adherence. This was a population-based historical cohort study including 51 975 adult CHB patients treated with entecavir (0.5 mg/d orally). Data were obtained from the Korean national health insurance service claims database, which covers >99% of the entire population, between 2007 and 2015. Medication adherence was categorized as high (proportion of days covered [PDC], ≥90%; n = 32 089), intermediate (PDC, 80%-89%; n = 10 197) and low (PDC, <80%; n = 9689). During a median 4.5 years (maximal 9 years) of follow-up in 51 975 CHB patients treated with entecavir, multivariable analyses revealed that the risk of mortality/transplantation was significantly greater in the low-adherers (adjusted hazard ratio [HR], 1.38; P < .001) and intermediate-adherers (adjusted HR, 1.44; P < .001) than the high-adherers (P for trend < 0.001). The risk of renal failure in the low- and intermediate-adherence groups was also significantly higher than the high-adherence group (P for trend < 0.001). By contrast, the risk of hepatocellular carcinoma (HCC) was not significantly different between groups (P for trend = 0.70). The higher risk of mortality/transplantation and renal failure but similar risk of HCC for low- and intermediate-adherers compared with high-adherers was consistent in inverse probability treatment weighting analysis of the entire cohort and subcohorts with or without cirrhosis. In conclusion, high medication adherence (≥90%) is required to significantly lower risk of mortality and renal failure in patients with CHB during long-term treatment with entecavir.

Short-term efficacy after switching from adefovir dipivoxil and tenofovir disoproxil fumarate therapy to tenofovir alaferamide for chronic hepatitis B

The aim of the present study was to evaluate the effects of switching to tenofovir alafenamide (TAF) in patients who had received a nucleos(t)ide analog (NA) for the treatment of chronic hepatitis B (CHB). The data from 33 Japanese patients with CHB who received TAF therapy after using NA [adefovir dipivoxil (ADV) and/or tenofovir disoproxil fumarate (TDF)] were retrospectively analyzed. Specifically, the biochemical and virological markers from the start of the TAF treatment to 6 months later were assessed. Comparative evaluation was performed by dividing patients into two groups: Long-term (n=19) and short-term administration groups (n=14), with a cutoff administration duration of 10 years. In all 33 patients, the levels of serum hepatitis B surface antigen (HBsAg; 1,126±1,724 to 1,001±1,591 IU/ml; P<0.0001), serum alkaline phosphatase (ALP) (320±126 to 283±124 U/l; P=0.028), serum bone specific alkaline phosphatase (19.7±9.0 to 17.7±8.0 µg/l; P=0.0006) and urine β2-microglobulin-creatinine ratio (U-BMG/Cr; 5,224±17,471 to 3,547±14,652 µg/g·Cre; P=0.002) significantly decreased from baseline after 6 months. Serum HBsAg, serum ALP and U-BMG/Cr showed a significant reduction in both groups. In conclusion, switching from ADV or TDF to TAF resulted in a decrease in serum HBsAg and improvement in serum ALP and U-BMG/Cr after 6 months of treatment in patients regardless of history of treatment with NA.

Association between liver cirrhosis and estimated glomerular filtration rates in patients with chronic HBV infection

To investigate the estimated glomerular filtration rates of chronic hepatitis B (CHB) patients with or without liver cirrhosis, and to explore the related risk factors.A total of 559 CHB patients were enrolled. Liver cirrhosis was diagnosed with ultrasound. The Child-Pugh scoring system was used to stage patients with liver cirrhosis. The Modification of Diet in Renal Disease (MDRD) formula was used to calculate the estimated glomerular filtration rate (eGFR).A total of 296 patients were involved. The results showed that the incidence of renal impairment in patients with liver cirrhosis was 8.45% (25/296). The incidence of renal impairment in Child-Pugh C patients was significantly higher than that in Child-Pugh B and Child-Pugh Grade A patients (i.e., 17.2% [17/99] vs 6.67% [7/105] vs 1.09% [1/92], respectively, P < .001); age, hyperuricemia, and Child-Pugh score are all risk factors for impaired renal function.With the deterioration of liver function in patients with cirrhosis, the incidence of impaired renal function has increased significantly, and renal function should be closely monitored to guide patients in clinical medication.

Kinetics of hepatitis B surface antigen and estimated glomerular filtration rate in telbivudine-treated hepatitis B patients with different rescue strategies

This study investigated the kinetics of estimated glomerular filtration rate (eGFR) and quantitative hepatitis B surface antigen (qHBsAg) in telbivudine (LdT)-treated chronic hepatitis B (CHB) patients whose treatment was subsequently adjusted with the adding on adefovir or by switching to tenofovir disoproxil fumarate (TDF) as rescue. Of 295 CHB patients initially treated with LdT, 102 of them who subsequently receiving either adding-on adefovir (group A, n = 58) or switching to TDF (group B, n = 44) for more than 24 months were enrolled. Serial eGFR and qHBsAg levels (3 to 6 monthly) in both LdT monotherapy and rescue therapy periods were analyzed retrospectively. Subsequent decline of qHBsAg especially in rescue therapy period were noted (p<0.001 and p = 0.068 in group A and B). However, patients in group B achieved a significant increase of eGFR (p = 0.010) in LdT monotherapy period but had a significant decline of eGFR (p<0.001) in rescue therapy period. In contrast, patients in group A maintained eGFR levels in both periods. Meanwhile, switch to TDF (hazard ratio: 3.036; 95% confidence interval: 1.040-8.861; p = 0.042) was the sole factor related to the decrease of eGFR>20% from baseline. Both rescue therapies achieved subsequent declines of qHBsAg over time but caused different changes in eGFR. LdT-based rescue therapy maintained eGFR but TDF switching therapy descended eGFR. Therefore, it is essential to monitor patient's renal function intensively when switching from LdT to TDF as a rescue strategy.

Association between body size-metabolic phenotype and nonalcoholic steatohepatitis and significant fibrosis

BACKGROUND AND AIMS

Body size-metabolic phenotype may help predict whether or not individuals with nonalcoholic fatty liver disease (NAFLD) develop advanced liver disease. We studied the association of body size-metabolic phenotype with nonalcoholic steatohepatitis (NASH) and significant fibrosis.

METHODS

Our cross-sectional study included 559 subjects (mean age of 53 years; women 51%) with biopsy-proven NAFLD. Clinical, genetic, and histological characteristic features of NAFLD were evaluated. The metabolically unhealthy phenotype was defined by the presence of two or more metabolic components, while body size was categorized based on body mass index: obese (≥ 25 kg/m²) or non-obese (< 25 kg/m²). Body size-metabolic phenotypes were divided into four study groups: (1) non-obese metabolic syndrome (MS)-, (2) non-obese MS+ , (3) obese MS-, and (4) obese MS+.

RESULTS

Obese MS- and non-obese MS+ groups demonstrated comparable levels of insulin resistance, adipose tissue insulin resistance indexes, and visceral adipose tissue (VAT) areas. The VAT area was significantly higher in the obese MS+ group versus obese MS- group. However, the VAT to subcutaneous adipose tissue (SAT) ratio was highest in the non-obese MS+ group. There was no difference in histology between the non-obese MS+, obese MS-, and obese MS+ groups. Multivariate analyses adjusted for age, sex, smoking status, PNPLA3, TM6SF2, and VAT/SAT areas demonstrated an independent and dose-dependent relationship between the body size-metabolic phenotype and NASH or significant fibrosis.

CONCLUSION

The non-obese MS+ group displayed similar degree of hepatic histological severity compared to their obese MS- counterparts. Metabolic milieu beyond obesity may play a pathogenic role in non-obese MS+ individuals who develop NASH with significant hepatic fibrosis.

CLINICAL TRIAL NUMBER

NCT02206841.

Bayesian Network Meta-Analysis for Assessing Adverse Effects of Anti-hepatitis B Drugs

BACKGROUND AND OBJECTIVE

Oral nucleoside/nucleotide analogues (NAs) have been advocated for chronic hepatitis B (CHB) treatment with good efficacy. However, less attention has been put on their adverse events. Therefore, a Bayesian network meta-analysis (NMA) was performed to evaluate the relative safety of five NAs (lamivudine, adefovir dipivoxil, entecavir, telbivudine, and tenofovir disoproxil fumarate) in CHB treatment among adults.

METHODS

Eligible randomized clinical trials (RCTs) and prospective cohort studies were systematically and thoroughly searched until May 1, 2019. Poisson-prior-based Bayesian NMA was performed to synthesize both direct and indirect evidence with reporting hazard ratios (HRs) and 95% credible intervals (CrIs) for serious adverse events (SAEs) and hepatic/renal impairments.

RESULTS

Thirty-three RCTs and 11 prospective cohort studies were identified. As to SAEs, no statistically significant difference was found of any comparison among five NAs. In terms of hepatotoxicity, lamivudine was safer than telbivudine (HR 0.45; 95% CrI 0.21, 0.85), and entecavir increased the risk by 102% (entecavir vs lamivudine: HR 2.02; 95% CrI 1.19, 3.27).

CONCLUSIONS

The findings from this large NMA could influence clinical practice, and the methodological framework of this study could provide evidence-based support to analyze sparse safety data in the field.

Significance of switching of the nucleos(t)ide analog used to treat Japanese patients with chronic hepatitis B virus infection from entecavir to tenofovir alafenamide fumarate

The significance of switching of the nucleos(t)ide analog used to treat patients with hepatitis B virus (HBV) from entecavir (ETV) to tenofovir alafenamide fumarate (TAF) is uncertain. The subjects of this study were 159 patients with HBV who received treatment with ETV followed by TAF. Among these patients, serial changes in the HBV marker levels were monitored in 92 patients in whom the serum HBsAg levels were ≥100 IU/mL during the 48-week period immediately before and after the switching. A questionnaire survey for medication compliance was performed in 127 patients. The serum HBsAg levels (log IU/mL) decreased by 0.041 during the ETV treatment period and by 0.068 during the TAF administration period. The degree of reduction was higher during the TAF administration period than during the ETV administration period in patients without cirrhosis (P = .030), patients with genotype B HBV (P = .014), and patients with undetectable serum HBcrAg (P = .038). Multivariate analysis revealed the HBV genotype (B vs C; odds ratio, 3.400; P = .025) and serum aspartate aminotransferase level (every 1+; 1.111; P = .015) at the time of switching as factors influencing the treatment efficacy. Thirty-six patients (28%) responded that the number of days that they forgot to take the drug decreased after the drug switching, and 77 patients (61%) reported feeling satisfied with the drug switching. Switching of the nucleos(t)ide analog used from ETV to TAF may be useful in the treatment of patients with HBV infection, as it is associated with both a decrease in the serum HBsAg level and improvement of the medication compliance.

In Vitro and In Vivo Renoprotective Effects of Telbivudine in Chronic Hepatitis B Patients Receiving Nucleotide Analogue

AIM

Renal toxicity of adefovir disoproxil (ADV) and tenofovir disoproxil fumarate (TDF) is a significant concern in chronic hepatitis B (CHB) patients. Early observational clinical data suggested that telbivudine (LdT) might have renoprotective effects.

METHODS

In this prospective study, consecutive CHB patients on combined lamivudine (LAM) + ADV/TDF were switched to LdT + ADV/TDF at recruitment and were followed up for 24 months. Estimated glomerular filtration rate (eGFR) was calculated with the modification of diet in renal disease equation. The effects of LdT on cell viability and expression of kidney injury or apoptotic biomarkers were investigated in cultured renal tubular epithelial cell line HK-2.

RESULTS

Thirty-one patients (median age 55 years, 90.3% male) were recruited (54.8% TDF: 45.2% ADV). Serum HBV DNA was undetectable at all time points. Median eGFR was 70.2 (IQR 62.6-77.9) and 81.5 (IQR 63.6-99.1) mL/min/1.73 m² at baseline and 24 months, respectively (p < 0.001). Downstaging of chronic kidney disease was observed in eight (25.8%) patients and was more common in ADV-treated compared to TDF-treated patients (7/8 vs. 1/17, p = 0.011; OR 16, 95% CI 1.643-155.766, p = 0.017). In vitro data showed that adding LdT to ADV or TDF was associated with improved cell viability and lower expression of injury and apoptotic biomarkers compared with ADV or TDF alone. Treatment was prematurely discontinued in four(12.9%) patients due to myalgia.

CONCLUSIONS

Clinical and in vitro data suggest that LdT has renoprotective effects in patients on long-term ADV/TDF treatment. LdT may be considered as an adjuvant therapy in this special group of patients with renal impairment (NCT03778567).

How to estimate renal function in patients with liver disease: choosing the most suitable equation

BACKGROUND

Hepatitis B virus (HBV) infection is a public health challenge, especially in China. In clinical practice, HBV infection is associated with nephropathy. Impaired renal function is frequently observed in compensated Chronic Hepatitis B (CHB) and cirrhosis (LC). Thus, renal function must be monitored to avoid nephrotoxic effects before and during nucleoside analog treatment. Investigating the predictive markers of early renal dysfunction is essential. New GFR-predicting equations, based on Pcr and/or CystC, have been recently recommended in the general population, but their performance in liver disease patients has been rarely studied. In this study, we will discuss how to detect renal dysfunction in patients with HBV infection.

METHODS

A total of 16 LC patients and 23 CHB patients were enrolled in this study, and we collected and compared the clinical data of the two groups. The estimated glomerular filtration rates (eGFRs) were also calculated by several equations. All patients received 99mTc-DTPA dynamic radionuclide imaging examinations to obtain mGFRs as the reference standard. To evaluate the performance of any equation in the CHB and LC groups, paired t test, Pearson's correlation, Kappa analysis and Bland-Altman plots were utilized. Moreover, all 39 subjects were divided into two groups (according to GFR > 90 mL/min/1.73 m²). We compared the serum and urinary markers of kidney injury between the two groups and selected the indicators of renal injury by univariate analysis.

RESULTS

The mGFR was 72.26 ± 20.69 mL/min/1.73 m² in the LC group, and 87.49 ± 25.91 mL/min/1.73 m² in the CHB group. The paired t test results of eGFR and mGFR showed no difference between eGFR (estimated by the CHINAcr-cys equation) and mGFR (p > 0.05) in the compensated LC and CHB groups. The difference between mGFR and eGFR estimated by other methods was obvious (p < 0.05). Comparing the eGFRs (estimated by 5 different equations) with mGFR in the compensated LC and CHB groups, Pearson's correlation showed that only eGFR (estimated by the CHINAcr-cys equation) had a significant correlation coefficient in CHB (r = 0.678, p = 0.000) and had the highest R² (R² = 0.459) among all other measures. The kappa consistency test showed that eGFR from CHINAscr-cys had poor consistency with mGFR in the compensated LC group but moderate consistency in the CHB group. Bland-Altman consistency analysis showed that in the CHB group, the CHINAcr-cys and CKD-EPIcr equations presented narrower acceptable limits than did the aMDRD, c-aMDRD, and CKD-EPIcr-cys equations (62.8, 56.1 vs .85.7, 102.9, 93.6 mL/min per 1.73 m²). In the compensated LC group, the CHINAcr-cys and CKD-EPIcr equations presented narrower acceptable limits than did the aMDRD, c-aMDRD, and CKD-EPIcr-cys equations (83.6, 81.3 vs. 98, 113.5, 106.3 mL/min per 1.73 m²). Serum or urinary markers were compared with renal function (GFR > 90 mL/min/1.73 m²) and showed International normalized ratio (INR) (p = 0.009), creatinine (p = 0.006), urine N-acetyl-β-glucosaminidase (NAG) (p = 0.001) and serum cystatin C (CysC) (p = 0.044).

CONCLUSION

The CHINAcr-cys equation may be more suitable for the estimation of GFR in Chinese patients with CHB or compensated cirrhosis. INR, creatinine, NAG, and CysC are proper biomarkers for screening renal dysfunction in Chinese patients with CHB or compensated LC.

Hepatitis B virus infection and development of chronic kidney disease: a cohort study

Background

The effect of chronic hepatitis B virus (HBV) infection on the risk of chronic kidney disease (CKD) is controversial. We examined the prospective association between hepatitis B surface antigen (HBsAg) serology status and incident CKD in a large cohort of men and women.

Methods

Cohort study of 299,913 adults free of CKD at baseline who underwent health screening exams between January 2002 and December 2016 in South Korea. Incident CKD was defined as the development of an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73m² and/or proteinuria.

Results

Over 1,673,701 person-years of follow-up, we observed 13,924 incident cases of CKD (3225 cases of eGFR < 60 ml/min/1.73m² and 11,072 cases of proteinuria). In fully adjusted models comparing positive to negative HBsAg participants, the hazard ratio (HR, 95% confidence interval) for incident CKD was 1.11 (1.03–1.21; P = 0.01). The corresponding HR for incident proteinuria and for eGFR < 60 ml/min/1.73m² were 1.23 (1.12–1.35; P <  0.001) and 0.89 (0.73–1.07; P = 0.21), respectively. The associations were similar across categories of liver enzyme levels at baseline.

Conclusion

In this large cohort, HBsAg positive serology was associated with higher risk of incident CKD, and we provide novel evidence that this association was due to a higher incidence of proteinuria in HBsAg positive participants. Our study adds to the growing body of evidence suggesting that chronic HBV infection may be a contributor to the increasing incidence of CKD.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1154-4) contains supplementary material, which is available to authorized users.

Longitudinal trends in renal function in chronic hepatitis B patients receiving oral antiviral treatment

BACKGROUND

Long term renal safety of antiviral agents against hepatitis B virus (HBV) has been debated.

AIM

To compare longitudinal trends of renal function among HBV mono-infected patients receiving entecavir (ETV), tenofovir disoproxil fumarate (TDF), and adefovir (ADV) in comparison to untreated subjects.

METHODS

A retrospective cohort consisting of 815 patients with chronic HBV infection was constructed. Serial estimated glomerular filtration rate (eGFR) was compared to the expected rate of age-dependent decline in eGFR, derived from the National Health and Nutrition Examination Survey (NHANES) data. Generalised estimating equations and linear mixed-effects models were used to compare trends in eGFR (in mL/min/1.73m² as a "unit").

RESULTS

In NHANES data (n = 23 051), each year of age was associated with a 0.86 unit decrease in eGFR in subjects without hypertension and 0.96 units with hypertension. The Stanford cohort consisted of patients who received ETV (n = 207), TDF (n = 191), ADV (n = 46) or no therapy (n = 371). After a median follow-up 4.0 (interquartile range: 1.9-6.5) years, there was no significant difference in the expected and observed rates of eGFR decline in untreated HBV patients. Patients receiving antiviral treatment experienced steeper reduction in renal function than expected. In the multivariable model, ETV was associated with eGFR loss at 1.81 units per year (P = 0.06, compared to untreated patients). TDF- and ADV-treated patients experienced significantly higher rate of eGFR loss at 2.21 and 2.63 units per year, respectively (both P < 0.01).

CONCLUSION

In this longitudinal cohort study, HBV patients receiving antiviral therapy, particularly TDF and ADV, experienced more rapid loss in eGFR.

Serum NGAL can act as an early renal safety biomarker during long-term nucleos(t)ide analogue antiviral therapy in chronic hepatitis B

Tubular renal toxicity is a side-effect of long-term therapy with nucleos(t)ide analogue(s) (NA) in chronic hepatitis B (CHB). There are no established surrogate markers in plasma of early NA-related toxicity. Neutrophil gelatinase-associated lipocalin (NGAL) is a protein produced by tubular cells following renal damage. We aimed therefore to retrospectively compare conventional renal markers (estimated glomerular filtration rates (eGFR) and urinary protein/creatinine ratio uPCR) with a sensitive biomarker (NGAL) in CHB patients on long-term NA therapy and assess the ability of new markers to predict NA-related renal toxicity (new onset of nonalbumin proteinuria). A total of 192 naïve CHB patients (median age 41 years, 78% males, 25% HBeAg+, 35% cirrhosis) were NA treated for at least 5 years (median 8.34 years, range 5.54-11.1 years). The eGFR and uPCR were compared at baseline and last clinical visit with serum NGAL concentrations measured by ELISA at same time-points and assessed according to the presence/absence of nonalbumin proteinuria at last visit. While baseline and last visit eGFR were similar (median:78 vs 84 mL/min), serum NGAL concentrations increased during therapy (median:9.4 vs 16.4 ng/mL, P < .05). The proportion of patients with proteinuria (uPCR > 15) increased between baseline and last visit (4.6% vs 21.4%, P < .05), with 30 (16%) patients having de novo nonalbumin proteinuria at last visit. High baseline NGAL concentrations were exclusive to patients with de novo nonalbumin proteinuria (median:31.7 vs 7.8 ng/mL, P < .01) and baseline NGAL levels >25 mg/mL were predictive of nonalbumin proteinuria at last visit (AUROC = 0.813). In conclusion, serum NGAL can act as a surrogate marker of early renal injury (de novo nonalbumin proteinuria) in CHB on long-term NA therapy.

Combined effect of pegylated interferon α with adefovir on renal function in Chinese patients with chronic hepatitis B

BACKGROUND

Long-term safety of treatment with hepatitis B virus (HBV) polymerase inhibitors is a concern. Adefovir dipivoxil (ADV) and/or interferon alfa (IFN-α) therapies have previously been associated with impairment of renal function. Limited data are available on the safety of combination therapy with nucleos (t)ide analogues (NAs) and IFN-α. The aim of this analysis was to assess the renal function during combined therapy with pegylated interferon α-2b (PEG-IFN-α-2b) and ADV versus PEG-IFN-α-2b alone in patients with chronic hepatitis B (CHB).

METHODS

We performed a multicenter, prospective, open-label, randomized-controlled trial of renal function data to investigate the efficacy of 48 weeks of therapy with PEG-IFN-α-2b and ADV versus PEG-IFN-α-2b alone in 102 patients with CHB in Anhui, China. Glomerular filtration rates (GFRs) were calculated by Cockcroft-Gault (CG), abbreviated Modification of Diet in Renal Disease (MDRD) study, and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation, and were tested by repeated-measures 1-way analysis of variance within groups. A linear mixed effects model for repeated measures was also used to evaluate the association between baseline information and estimated glomerular filtration rate (eGFR) changes overtime in all enrolled patients. The model considered the baseline age, sex, HBV DNA, aminotransferase, treatment group, time, and group-by-time interaction as fixed effects and incorporated random effects for individual subjects.

RESULTS

After 48 weeks of therapy and further 24 weeks of follow-up, the eGFR decreased both in patients given PEG-IFN-α-2b single therapy and combined therapy. Age, HBV DNA, and combined therapy were significant negative predictive factors for eGFR changes.

CONCLUSION

The incidence of renal adverse events in both groups was low, and the combination therapy may have delayed, but reversible renal impairment.

Effect of adding on telbivudine or switching to telbivudine alone on therapeutic efficacy and renal function in chronic hepatitis B patients on adefovir dipivoxil monotherapy

AIM

To explore the serum conversion rate of hepatitis B e antigen (HBeAg) and renal function in patients with chronic hepatitis B (CHB) treated with aldefovir dipivoxil (ADV) plus telbivudine (L-DT).

METHODS

This retrospective cohort study included 42 patients with HBeAg-negative CHB who were on ADV (10 mg) monotherapy. Twenty patients were treated with L-DT add-on therapy (combination therapy group), and 22 patients were switched to ETV monotherapy (monotherapy group). At 24 and 48 wk, the conversion rate of HBeAg and renal function evaluated by estimated glomerular filtration rate (eGFR) were analyzed and compared between the two groups.

RESULTS

The eGFR at 24 and 48 wk did not differ significantly between the two groups (P = 0.773, 0.108). The eGFR in the combination therapy group was significantly higher at 48 wk than at baseline (t = -6.184, P < 0.05), but no significant difference was observed in the monotherapy group (t = -0.893, P > 0.05). The serum conversion rates of HBeAg at 24 wk and 48 wk were significantly higher in the combination therapy group than in the monotherapy group (P = 0.043, 0.034).

CONCLUSION

L-DT based treatment is effective in elevating the serum conversion rate of HBeAg, and long-term therapy is associated with sustained improvement of renal function, particularly among HBeAg-negative CHB patients treated with ADV.

Nationwide cohort study suggests that nucleos(t)ide analogue therapy decreases dialysis risk in Taiwanese chronic kidney disease patients acquiring hepatitis B virus infection

AIM

To investigate the risk of end-stage renal disease (ESRD) in hepatitis B virus (HBV)-infected patients with chronic kidney disease (CKD) with and without nucleos(t)ide analogue (NA) therapy.

METHODS

This nationwide cohort study included 103444 Taiwanese CKD adults without hepatitis C virus infection from the Taiwan Longitudinal Health Insurance Database 2005 between 1997 and 2012. We identified 2916 CKD patients who acquired HBV infection and did not receive NAs (untreated cohort), and they were propensity-matched 1:4 with 11664 uninfected counterparts. We also identified 442 CKD patients who acquired HBV infection and received NAs (treated cohort), and they were propensity-matched 1:3 with 1326 untreated counterparts. The association between HBV infection, NA use, and ESRD was analyzed using competing risk analysis.

RESULTS

Multivariable Cox regression analysis showed a 1.67-fold higher risk (P < 0.0001) of ESRD in the untreated cohort (16-year cumulative incidence, 10.1%) than in the matched uninfected cohort (16-year cumulative incidence, 6.6%), which was independent of cirrhosis or diabetes. The treated cohort (16-year cumulative incidence, 2.2%) had an 87% lower ESRD risk (P < 0.0001) compared with the matched untreated cohort (16-year cumulative incidence, 11.9%). The number needed to treat for one fewer ESRD after NA use at 12 years was 12. Multivariable stratified analyses verified these associations in all subgroups.

CONCLUSION

This study suggests that untreated HBV infection and NA therapy are associated with increased and decreased risk of ESRD, respectively, in CKD patients. Identification of HBV status and targeted monitoring for ESRD development are important in CKD patients living in HBV-endemic areas.

Prevalence of chronic kidney disease in patients with chronic hepatitis B: A cross-sectional survey

Renal safety is a major concern during long-term antiviral treatment for chronic hepatitis B (CHB). This study aimed to investigate the prevalence of chronic kidney disease (CKD) in patients with CHB that had been treated with antiviral therapy. This was a single-centre, cross-sectional study in a real-life cohort in which all patients received antiviral treatment. Serum creatinine-based equations from the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) were used to estimate the glomerular filtration rate (GFR). CKD was defined as an eGFR <60 mL/min/1.73 m² or a urinary albumin to creatinine ratio ≥ 3 mg/mmol (defined as albuminuria). Univariate and multivariate analyses were conducted to determine the risk factors of CKD. A total of 1985 patients were included in the analysis from February 2015 to December 2015. The mean age and median duration of antiviral treatment was 42.20 years and 17.05 months, respectively. The overall prevalence of CKD was 7.9% (157/1985), with 44 patients experiencing decreased renal function (eGFR less than 60 mL/min/1.73 m²) and 129 patients with albuminuria. Patients with cirrhosis had a higher prevalence of a decreased GFR (4.3% vs 1.6%, P<.001) and albuminuria (11.1% vs 5.2%, P<.001) than those without cirrhosis. In the multivariate analysis, hypertension (Odds Ratio [OR] 4.564, P<.001), diabetes mellitus (OR 2.688, P<.001) and cirrhosis (OR 1.918, P<.001) were independent factors associated with the presence of CKD. CKD was a clinically significant comorbidity in patients with CHB. Special attention should be paid to cirrhotic patients and patients with the metabolic syndrome.

Tenofovir alafenamide as compared to tenofovir disoproxil fumarate in the management of chronic hepatitis B with recent trends in patient demographics

Tenofovir alafenamide (TAF) has recently been approved for chronic hepatitis B (CHB). It is more stable than tenofovir disoproxil fumarate (TDF) in the plasma and can provide similar efficacy with lower circulating concentration in patients with hepatitis B virus (HBV) infection. Areas covered: This synopsis will review the current anti-HBV standard practice and the changing epidemiology of CHB, specifically the controversies surrounding the renal and bone safety associated with TDF use in the context of an aging CHB population. We will review data from phase 3 registration trials, which demonstrated TAF was not inferior to TDF in antiviral efficacy for both HBeAg-positive and HBeAg-negative patients, while associated with less reduction in the estimated glomerular filtration rate and bone mineral density. Expert commentary: Current data supports the use of TAF as one of the first-line antiviral agents for general CHB patients without hepatic decompensation. However, more real-world data with long-term observation are needed to better define the role of TAF among other oral regimens. Additional studies are also needed to evaluate the efficacy and safety of TAF in special populations such as those with impaired hepatic function, existing impaired renal and/or bone function, and in pregnant women.

Factors Related to Significant Improvement of Estimated Glomerular Filtration Rates in Chronic Hepatitis B Patients Receiving Telbivudine Therapy

BACKGROUND AND AIM

The improvement of estimated glomerular filtration rates (eGFRs) in chronic hepatitis B (CHB) patients receiving telbivudine therapy is well known. The aim of this study was to clarify the kinetics of eGFRs and to identify the significant factors related to the improvement of eGFRs in telbivudine-treated CHB patients in a real-world setting.

METHODS

Serial eGFRs were calculated every 3 months using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. The patients were classified as CKD-1, -2, or -3 according to a baseline eGFR of ≥90, 60-89, or <60 mL/min/1.73 m², respectively. A significant improvement of eGFR was defined as a more than 10% increase from the baseline.

RESULTS

A total of 129 patients were enrolled, of whom 36% had significantly improved eGFRs. According to a multivariate analysis, diabetes mellitus (DM) (p = 0.028) and CKD-3 (p = 0.043) were both significantly related to such improvement. The rates of significant improvement of eGFR were about 73% and 77% in patients with DM and CKD-3, respectively.

CONCLUSIONS

Telbivudine is an alternative drug of choice for the treatment of hepatitis B patients for whom renal safety is a concern, especially patients with DM and CKD-3.

Clinical impact of the early alanine amininotransferase flare during tenofovir monotherapy in treatment-naïve patients with chronic hepatitis B

BACKGROUND/AIMS

Little is known about the effect of early flares on response during first-line tenofovir disoproxil fumarate (TDF) treatment for chronic hepatitis B (CHB). The aim of this study was to investigate the incidence and outcome of early alanine aminotransferase (ALT) flare in treatment-naive patients with CHB during long-term TDF monotherapy.

METHODS

One hundred eighty-one treatment-naive CHB patients were treated with a 300-mg once-daily dose of TDF for more than 12 weeks. Virological markers of hepatitis B virus (HBV) and biochemical data were measured at baseline and every 4-12 weeks during the therapy. The proportion of patients with undetectable HBV DNA level (< 100 copies/mL) was noted.

RESULTS

The median age was 48.3 years and 122 patients (67.4%) were men. Hepatitis B envelope antigen (HBeAg) was positive in 101 patients (55.8%). No patient had cirrhosis. The median follow-up duration was 45 weeks (12-155 weeks). ALT flare (>5 × upper limit of the normal range) occurred in seven patients (3%) without viral breakthrough within the first 8 weeks after the start of TDF monotherapy. Among them, six patients were HBeAg-positive and one patient was HBeAg-negative. All cases of early ALT flares resolved within 4 weeks and virologic response was observed in all patients without interruption or discontinuation of treatment.

CONCLUSIONS

Continuous TDF monotherapy was effective and safe in treatment-naive patients with CHB who experienced early ALT flares followed by a decrease in HBV DNA level.

Adverse effects of oral antiviral therapy in chronic hepatitis B

Oral nucleoside/nucleotide analogues (NAs) are currently the backbone of chronic hepatitis B (CHB) infection treatment. They are generally well-tolerated by patients and safe to use. To date, a significant number of patients have been treated with NAs. Safety data has accumulated over the years. The aim of this article is to review and update the adverse effects of oral NAs. NAs can cause class adverse effects (i.e., myopathy, neuropathy, lactic acidosis) and dissimilar adverse effects. All NAs carry a “Black Box” warning because of the potential risk for mitochondrial dysfunction. However, these adverse effects are rarely reported. The majority of cases are associated with lamivudine and telbivudine. Adefovir can lead to dose- and time-dependent nephrotoxicity, even at low doses. Tenofovir has significant renal and bone toxicity in patients with human immunodeficiency virus (HIV) infection. However, bone and renal toxicity in patients with CHB are not as prominent as in HIV infection. Entecavir and lamivudine are not generally associated with renal adverse events. Entecavir has been claimed to increase the risk of lactic acidosis in decompensated liver disease and high Model for End-Stage Liver Disease scores. However, current studies reported that entecavir could be safely used in decompensated cirrhosis. An increase in fetal adverse events has not been reported with lamivudine, telbivudine and tenofovir use in pregnant women, while there is no adequate data regarding entecavir and adefovir. Further long-term experience is required to highlight the adverse effects of NAs, especially in special patient populations, including pregnant women, elderly and patients with renal impairment.

Association between hepatitis B virus and chronic kidney disease: a systematic review and meta-analysis

 Background. Hepatitis B virus infection and chronic kidney disease are prevalent and remain a major public health problem worldwide. It remains unclear how infection with hepatitis B virus impacts on the development and progression of chronic kidney disease.

AIM

To evaluate the effect of infection with HBV on the risk of chronic kidney disease in the general population.

MATERIAL AND METHODS

We conducted a systematic review of the published medical literature to determine if hepatitis B infection is associated with increased likelihood of chronic kidney disease. We used the random effects model of DerSimonian and Laird to generate a summary estimate of the relative risk for chronic kidney disease (defined by reduced glomerular filtration rate and/or detectable proteinuria) with hepatitis B virus across the published studies. Meta-regression and stratified analysis were also conducted.

RESULTS

We identified 16 studies (n = 394,664 patients) and separate meta-analyses were performed according to the outcome. The subset of longitudinal studies addressing ESRD (n = 2; n = 91,656) gave a pooled aHR 3.87 (95% CI, 1.48; 6.25, P < 0.0001) among HBV-infected patients and no heterogeneity was recorded. In meta-regression, we noted the impact of male (P = 0.006) and duration of follow- up (P = 0.007) upon the adjusted hazard ratio of incidence of chronic kidney disease (including end-stage renal disease). No relationship occurred between HBV positive status and prevalent chronic disease (n = 7, n = 109,889 unique patients); adjusted odds ratio, were 1.07 (95% CI, 0.89; 1.25) and 0.93 (95% CI, 0.76; 1.10), respectively.

CONCLUSIONS

HBV infection is possibly associated with a risk of developing reduced glomerular filtration rate in the general population; no link between HBV sero-positive status and frequency of chronic kidney disease or proteinuria was noted in cross-sectional surveys.

The efficacy and safety comparison between tenofovir and entecavir in treatment of chronic hepatitis B and HBV related cirrhosis: A systematic review and Meta-analysis

BACKGROUND

The purpose of this study was to assess the efficacy and safety between tenofovir and entecavir in the treatment of CHB and HBV related cirrhosis through Meta-analysis. Methods The electronic databases of PubMed, the Cochrane Library, Nature, CNKI and WanFang data were searched. The key words were: ("tenofovir", "entecavir") and ("Chronic Hepatitis B" or "CHB") and "Liver cirrhosis". Heterogeneity and report bias were analyzed.

RESULTS

There was significant difference of ALT norm level in the short-term period of 3months (RR=1.43, 95%CI: 1.06-1.94, P<0.017) and 6months (RR=0.89, 95%CI: 0.81-0.97, P<0.017), and significant difference of undetectable HBV-DNA only in 3months follow-up period (RR=1.59, 95%CI: 1.04-2.42, P<0.017) between TDF and ETV, but no significant difference in the long-term period. There is significant difference between TDF and ETV in eGFR level (RR=1.601, 95%CI: 1.035-2.478, P=0.0034) and hypophosphatemia incidence (RR=4.008, 95%CI: 1.485-10.820, P=0.006).

CONCLUSION

TDF has a better efficacy than ETV in 3months treatment duration, but intriguingly, TDF might not better than ETV during the 6months treatment period in the viral suppression and liver function improvement. There's no significant difference between TDF and ETV in the long-term treatment duration and in the treatment of HBV related liver cirrhosis. Both TDF and ETV could influence renal function but patients under TDF therapy may have more risk to suffer from renal damage and hypophosphatemia.

Relationship between nephrotoxicity and long-term adefovir dipivoxil therapy for chronic hepatitis B: A meta-analysis

BACKGROUND

To assess the relationship between adefovir dipivoxil and renal function after anti-hepatitis B virus therapy and elucidate the risk factors involved.

METHODS

Based on the requirements of the Cochrane systematic review methodology, 21 observational articles on adefovir dipivoxil-associated renal dysfunction were obtained by searching various databases, between January 1, 1995 and July 1, 2016. The Newcastle Ottawa Scale was used to evaluate risk bias. Parameters for 4276 chronic hepatitis B patients were analyzed by Review Manager and R software, and glomerular filtration rate, creatinine clearance, and serum creatinine values were extracted to evaluate renal function.

RESULTS

Renal dysfunction was more likely to occur in patients receiving the adefovir dipivoxil therapy (odds ratio [OR] 1.98, 95% confidence interval [CI] 1.40-2.80) than the none-adefovir dipivoxil group. Subgroup analysis showed that renal function predictive value is higher for glomerular filtration rate (OR 2.42, 95% CI 1.34-3.14), compared with serum creatinine levels (OR 1.51, 95% CI 0.75-3.04). The rate of adefovir dipivoxil-associated renal dysfunction was 12% (95% CI 0.08-0.16). Older patients and patients with renal insufficiency, hypertension, and diabetes mellitus were more prone to developing adefovir dipivoxil-associated renal dysfunction; however, integrated raw data were insufficient for further detailed analysis.

CONCLUSION

Long-term adefovir dipivoxil therapy is connected to renal dysfunction in chronic hepatitis B, necessitating the monitoring of kidney function.

Tenofovir and kidney transplantation: case report

Background: Hepatitis B viral infection (HBV) has been regarded as a contraindication for kidney transplantation because of the high risk of viral activation induced by immunosuppressive therapy. Anti-retroviral drugs have changed the prognosis of patients with hepatitis B viral infection (HBV+) who are candidates for renal transplant; indeed, therapy with antiretroviral drugs may ensure lower rates of morbidity and mortality compared to traditional therapies. Entecavir is the first-line antiviral therapy recommended for the treatment of HBV+ kidney-transplanted patients. In case of resistance to entecavir, tenofovir may be an alternative drug, either alone or in combination with entecavir. However, the best strategy of treatment is still unknown. In this case-report, a HBV+ kidney-transplanted patient who presented resistance to entecavir was initially treated by associating tenofovir to entecavir and with tenofovir alone afterward. This strategy induced complete remission of viral replication. Case presentation: In a HBV+ kidney-transplanted patient under monotherapy with entecavir, HBV flare (HBV DNA > 170.000 × 10³ UI/mL, HBeAg+, HbeAb–) occurred 9 months after transplantation; at that time, blood chemistry highlighted: creatinine 1.46 mg/dL, blood urea 65 mg/dL, e-GFR 50 mL/min, proteinuria 300 mg/24 h, calciuria 2,12 mmol/24 h, phosphaturia 0.56 g/24 h, vitamin D 11.5 ng/mL, PTH 130 pg/mL, calcemia 2.3 mmol/L, and phosphoremia 2 mg/dL. Liver elastometry (FibroScan) showed moderate fibrosis. Tenofovir was associated to entecavir. Three months after the combination therapy, reduction in HBV DNA replication (351 × 10³ UI/mL) was obtained. Creatinine and e-GFR were 1.48 mg/dL and 52 mL/min, respectively. At this point, entecavir was discontinued. After 13 months of tenofovir monotherapy, complete remission of viral replication was achieved but renal function deteriorated and proteinuria increased. Conclusion: This case-report indicates that tenofovir is effective in reducing viral replication of hepatitis B virus in a kidney-transplanted patient who presented resistance to previous treatment with entecavir. However, it should be taken into account that tenofovir could affect renal function.

Renal outcomes after up to 8 years of tenofovir exposure in HIV-HBV-coinfected patients

BACKGROUND

Renal toxicity is a common side effect during tenofovir (TDF)-use in HIV-infected, but not necessarily HBV-infected, patients. Nevertheless, little is known regarding TDF-use on renal impairment during HIV-HBV coinfection. We aimed to evaluate the progression and determinants of renal impairment in coinfected patients undergoing TDF.

METHODS

A total of 175 coinfected patients initiating TDF-containing antiretroviral therapy were prospectively followed. Estimated glomerular filtration rates (eGFR) were calculated at baseline and every 6-12 months. Determinants of eGRF change from baseline (ΔeGFR) were evaluated using mixed-effect linear regression and progression towards renal impairment using proportional-hazards regression.

RESULTS

At baseline, average eGFR was 96.7 ml/min per 1.73m² (95% CI 93.8, 99.6). During a median 58.3 months (IQR 33.7-92.1) of treatment, eGFR decreased a monthly average of -0.14 ml/min per 1.73m² (95% CI -0.16, -0.12). Significantly faster ΔeGFR was associated with baseline eGFR>90 (P=0.002), male gender (P=0.04), previous AIDS-defining illness at baseline (P=0.03), baseline liver cirrhosis (P=0.03) and concomitant protease inhibitor use (P=0.005). Between respective baseline and end of follow-up visits, the proportion of patients with renal impairment increased: normal function, 65.7% to 53.1%; mild impairment, 32.6% to 40.0%; moderate impairment, 1.7% to 6.9%. Higher age (P=0.01) and previous AIDS-defining illness (P=0.02) at baseline were independent risk-factors for developing impairment, while undetectable HBV DNA on-treatment was protective (P=0.006). Five (2.9%) patients permanently discontinued TDF after a renal event.

CONCLUSIONS

Severe HIV-related and HBV-related morbidity negatively affects renal function in coinfected patients undergoing long-term TDF. Although most patients only developed mild/moderate impairment, close renal monitoring is warranted for this particular population.

Review article: long-term safety of nucleoside and nucleotide analogues in HBV-monoinfected patients

BACKGROUND

Nucleos(t)ide analogues (NUCs) for chronic hepatitis B treatment achieve high rates of viral suppression and are generally well tolerated. Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are the currently preferred first-line agents. The safety of these agents in clinical practice is particularly relevant since long-term treatment is usually required.

AIM

To summarise and critically discuss recent real-world evidence on the safety of treatment with ETV or TDF in hepatitis B virus (HBV)-monoinfected patients.

METHODS

PubMed and conference proceedings up to 15th June 2015 were searched using the terms ((((Hepatitis_B) OR HBV) AND ((tenofovir) OR entecavir)) AND (((lactic_acidosis) OR bone) OR renal)).

RESULTS

In selected populations included in registration studies, both ETV and TDF were well tolerated with no clinically significant renal toxicity or lactic acidosis. Growing 'real-world' clinical experience with these agents includes some reports of ETV-associated lactic acidosis and TDF-associated renal impairment; however, evidence from cohort studies appears to be conflicting. In the case of ETV-related lactic acidosis, a small number of cases have been reported, all in patients with decompensated cirrhosis. The degree of association between TDF treatment and changes in markers of renal function varies between studies: discrepancies may result from the use of different definitions and cut-offs for reporting renal toxicities, and differences in patient populations.

CONCLUSIONS

Pre-treatment and on-treatment monitoring of eGFR and phosphorus, with prompt appropriate dose adjustment or treatment switch can minimise the impact of NUC renal toxicity. Standardisation of measures of renal impairment and identification of early molecular markers remain an unmet need.

Tenofovir-associated nephrotoxicity in patients with chronic hepatitis B: two cases

Tenofovir disoproxil fumarate (TDF) is effective against chronic hepatitis B (CHB) infection and its use is increasing rapidly worldwide. However, it has been established that TDF is associated with renal toxicity in human immunodeficiency virus-infected patients, while severe or symptomatic TDF-associated nephrotoxicity has rarely been reported in patients with CHB. Here we present two patients with TDF-associated nephrotoxicity who were being treated for CHB infection. The first patient was found to have clinical manifestations of proximal renal tubular dysfunction and histopathologic evidence of acute tubular necrosis at 5 months after starting TDF treatment. The second patient developed acute kidney injury at 17 days after commencing TDF, and he was found to have membranoproliferative glomerulonephritis with acute tubular injury. The renal function improved in both patients after discontinuing TDF. We discuss the risk factors for TDF-associated renal toxicity and present recommendations for monitoring renal function during TDF therapy.

Renal Function in Nucleos(t)ide Analog-Treated Patients With Chronic Hepatitis B: A Systematic Literature Review and Network Meta-Analysis

INTRODUCTION

Renal safety is an important factor in selecting the most appropriate nucleos(t)ide analog (NA) treatment for patients with chronic hepatitis B (CHB). This systematic literature review and network meta-analysis aimed to assess renal function associated with telbivudine treatment compared to other NAs in patients with CHB.

METHODS

A systematic literature search via Medline, Medline In-Process, Embase, and the Cochrane library for publications of randomized controlled trials and observational studies was conducted. Network meta-analysis was performed to compare renal function with telbivudine treatment versus other NAs after 1 year of therapy.

RESULTS

Overall, 40 (six randomized controlled and 34 observational) studies were included for review. Telbivudine consistently showed an improvement in renal function as measured by an estimated glomerular filtration rate (eGFR) over various time points regardless of the method of measurement. Changes in eGFR (mL/min) from baseline and corresponding 95% credible intervals with various NAs were as follows: monotherapies (telbivudine: 7.78 [6.91, 8.65], entecavir: -1.07 [-4.80, 2.62], lamivudine: -6.08 [-13.35, 1.15], tenofovir: -9.53 [-14.31, -4.89]) and combination therapies (telbivudine + adefovir: 8.37 [-34.00, 50.34], telbivudine + tenofovir: 8.29 [-0.05, 16.64], entecavir + adefovir: 4.15 [-38.55, 46.37], telbivudine + lamivudine: 0.51 [-11.77, 12.96], and lamivudine + adefovir: -0.39 [-42.48, 41.21]). At 1 year, the change in eGFR from baseline was significantly higher with telbivudine compared to other NAs.

CONCLUSION

The systematic literature review and network meta-analysis provide evidence that telbivudine is associated with significant improvement in renal function in patients with CHB, either alone or in combination with other NAs.

FUNDING

Novartis Pharma AG.

Potential effects of telbivudine and entecavir on renal function: a systematic review and meta-analysis

Background

To assess the potential effects of telbivudine (LdT) and entecavir (ETV) on renal function in patients with chronic hepatitis B (CHB), we performed a meta-analysis of the relevant data available on these agents to evaluate their effects on the estimated glomerular filtration rate (eGFR) during treatment.

Methods

The PubMed, EMBASE, Scopus, CNKI (China National Knowledge Infrastructure), Cochrane Library, and WanFang databases were searched for relevant articles appearing in the literature up to July 1, 2015. A total of 6 studies (1960 CHB patients) with 1-year eGFR outcomes were retrieved and analyzed.

Results

Generally, the results of the 6 studies analyzed showed that eGFR was improved after LdT treatment, but was decreased after ETV treatment. Using a fixed-effects approach, the change in eGFR was found to be significantly different between LdT and ETV treatment (Z = 3.64; P = 0.0003). Whereas the eGFR was slightly decreased with ETV compared with baseline (−1.45 mL/min/1.73 m²), the eGFR was improved with LdT (2.99 mL/min/1.73 m²) after 1 year of treatment. An overall test of effect in the meta-analysis showed that the eGFR in LdT-treated patients was significantly improved after 1-year of treatment (Z = 3.71; P = 0.0002).

Conclusion

This meta-analysis has confirmed that LdT has a renal protective effect whereas ETV does not. However, whether the benefit on renal function outweighs the occurrence of resistance in specific clinical situations is not yet clear.

Telbivudine protects against renal impairment in patients with chronic hepatitis B infection

It has been reported that treatment with telbivudine might be associated with a significant improvement of renal function in patients with chronic hepatitis B. To confirm this finding, a systematic literature review was conducted. Four online databases (PubMed, CNKI/FMJS, Ovid and SpringerLink) were searched. Serum creatinine, glomerular filtration rate and estimated glomerular filtration rate changes from baseline to the end of the treatment were analyzed. A total of seven full-text articles and 13 abstracts with sample sizes ranging from 15 to 689 patients fulfilled the selection criteria for review. The results showed that long-term treatment with telbivudine, either as monotherapy or combined with other nucleos(t)ide analogs, can significantly improve renal function in chronic hepatitis B patients, particularly those at high risk of renal impairment.

DNA polymerase inhibitors for treating hepatitis B: a safety evaluation

INTRODUCTION

Oral nucleoside/ nucleotide analogues (NAs) are currently the mainstay of treatment for patients with chronic hepatitis B virus (HBV) infection. They are generally safe to use. However, since their approval in the last decade and a half, the literature has reported adverse effects associated with the use of NA in HBV patients. A comprehensive review on the drug safety is lacking.

AREAS COVERED

Significant adverse effects associated with NA use in HBV patients including muscle toxicity, peripheral neuropathy, nephrotoxicity and lactic acidosis are discussed. The reported prevalence of each adverse effect, as well as their predictive factors, reversibility and their use in pregnancy and lactating mothers are covered in this review. Novel data regarding reno-protective effect of telbivudine are also discussed.

EXPERT OPINION

Use of NA in HBV is generally safe. Uncommon adverse effects can be minimized or detected early if clinicians exercise adequate precautions when using NA for at-risk populations with regular monitoring.

Tenofovir monotherapy for hepatitis B after 1 year does not produce renal dysfunction, but is associated with hyperparathyroidism not related to vitamin D

INTRODUCTION

Viral hepatitis B (VHB) represents a major public health problem. Studies from HIV multidrug patients have associated the use of tenofovir disoproxil fumarate (TDF) with renal dysfunction and phosphate wasting.

OBJECTIVE

The aim of this study was to examine the effect of year-long TDF monotherapy on renal function in VHB patients.

PATIENTS AND METHODS

We evaluated adult patients diagnosed with VHB before treatment initiation (T0), and after 3 and 12 months (T3 and T12) of TDF initiation. Estimated glomerular filtration rate (eGFR) was estimated by serum cystatin C and creatinine. In addition, urinary electrolytes and tubular biomarkers (cystatin C, β2-microglobulin and neutrophil gelatinase-associated lipocalin) were analyzed, as well as parathyroid hormone (PTH) and 25(OH)vitamin D levels.

RESULTS

After 1 year, 32 patients completed the study, 22 (68.7%) men and 12 (37.5%) Whites, mean age 44.1±12.0 years. We found that serum electrolytes were similar at baseline and 3 or 12 months after initiation of TDF monotherapy. In addition, urinary fractional excretions of electrolytes as well as proteinuria, albuminuria, urinary β2-microglobulin, and urinary cystatin C showed no significant differences across the treatment timeline. There were also no statistical differences in the eGFR. There was a statistically significant increase in the PTH (Friedman's test, P=0.012), but the 25(OH)vitamin D levels were in the normal range in the beginning and did not change at the follow-up. Moreover, there was no correlation between the initial levels of vitamin D and the corresponding increases in the PTH values.

CONCLUSION

If used as monotherapy in hepatitis B patients for a 12-month period, TDF is not associated with changes in either eGFR or a panel of urinary biomarkers. Serum and urinary electrolytes also remained unchanged. Of note, a significant increase in the PTH was found, although not related to the 25(OH)vitamin D initial status.

Antiviral therapy for chronic hepatitis B viral infection in adults: A systematic review and meta-analysis

Chronic hepatitis B viral (HBV) infection remains a significant global health problem. Evidence-based guidelines are needed to help providers determine when treatment should be initiated, which medication is most appropriate, and when treatment can safely be stopped. The American Association for the Study of Liver Diseases HBV guideline methodology and writing committees developed a protocol a priori for this systematic review. We searched multiple databases for randomized controlled trials and controlled observational studies that enrolled adults ≥18 years old diagnosed with chronic HBV infection who received antiviral therapy. Data extraction was done by pairs of independent reviewers. We included 73 studies, of which 59 (15 randomized controlled trials and 44 observational studies) reported clinical outcomes. Moderate-quality evidence supported the effectiveness of antiviral therapy in patients with immune active chronic HBV infection in reducing the risk of cirrhosis, decompensated liver disease, and hepatocellular carcinoma. In immune tolerant patients, moderate-quality evidence supports improved intermediate outcomes with antiviral therapy. Only very low-quality evidence informed the questions about discontinuing versus continuing antiviral therapy in hepatitis B e antigen-positive patients who seroconverted from hepatitis B e antigen to hepatitis B e antibody and about the safety of entecavir versus tenofovir. Noncomparative and indirect evidence was available for questions about stopping versus continuing antiviral therapy in hepatitis B e antigen-negative patients, monotherapy versus adding a second agent in patients with persistent viremia during treatment, and the effectiveness of antivirals in compensated cirrhosis with low-level viremia.

CONCLUSION

Most of the current literature focuses on the immune active phases of chronic HBV infection; decision-making in other commonly encountered and challenging clinical settings depends on indirect evidence.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Risk Factors for Renal Functional Decline in Chronic Hepatitis B Patients Receiving Oral Antiviral Agents

Renal functional decline that is frequently seen during chronic hepatitis B (CHB) treatment can exert adverse effects on overall prognosis. It, however, is difficult to distinguish vulnerable patients who may experience renal dysfunction because most previous CHB studies were conducted in relatively healthy individuals. In this retrospective observational study, renal functional decline in CHB patients receiving oral antiviral agents for more than 6 months was analyzed and risk factors of chronic kidney disease (CKD) progression were determined. Renal functional decline was defined when the estimated glomerular filtration rate (eGFR) decreased by more than 25% from baseline and rapid CKD progression was defined as eGFR decreased by more than 5 mL/min/1.73 m2/y among patients who experienced renal functional decline. A total of 4178 patients were followed up for a median 23 months. Antiviral agents included lamivudine (17.0%), adefovir (3.7%), entecavir (70.4%), telbivudine (0.6%), tenofovir (4.0%), or clevudine (4.3%). Renal functional decline occurred in 706 (16.9%) patients. Based on multivariate Cox regression analysis, age, hypertension, diabetes, history of liver or kidney transplantation, underlying underlying CKD, and simultaneous administration of diuretics increased the hazard ratio for renal functional decline; however, clevudine reduced risk. The eGFR significantly increased over time in patients receiving telbivudine or clevudine compared with lamivudine. Among the 3175 patients followed up for more than 1 year, 407 (12.8%) patients experienced rapid CKD progression. Patients with rapid CKD progression showed lower serum albumin, higher total bilirubin, and prolonged prothrombin time compared with patients with stable renal function, but hepatitis B envelope antigen positivity and hepatitis B virus deoxyribonucleic acid level did not differ between the control and rapid CKD progression groups. Age, diabetes, kidney transplantation, underlying CKD, and simultaneous administration of diuretics were identified as risk factors for rapid CKD progression, and clevudine showed a beneficial effect. Age, hypertension, diabetes, liver or kidney transplantation, underlying CKD, and diuretics were identified as risk factors for renal functional decline. This study suggests that close monitoring of renal function and adequate management are required for CHB patients receiving antiviral agents with these risk factors.

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

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

13-year nationwide cohort study of chronic kidney disease risk among treatment-naïve patients with chronic hepatitis B in Taiwan

Background

Chronic hepatitis B virus (HBV) infection and chronic kidney disease (CKD) have high prevalences in Taiwan and worldwide. However, the association of untreated chronic hepatitis B virus (HBV) infection with chronic kidney disease (CKD) remains unclear.

Methods

This cohort study used claims data in the Taiwan National Health Insurance Research Database in 1996–2010, in which all diseases were classified by ICD-9-CM codes. We identified 17796 adults who had chronic HBV infection and did not take nucleos(t)ide analogues from 1998 to 2010 and also randomly selected 71184 matched controls without HBV in the same dataset. Cumulative incidences and adjusted hazard ratio (aHR) of incident CKD were evaluated through the end of 2010 after adjusting for competing mortality.

Results

The risk of CKD was significantly higher in the HBV cohort (13-year cumulative incidence, 6.2 %; 95 % confidence interval [CI], 5.4–7.1 %) than in the non-HBV cohort (2.7 %; 95 % CI, 2.5–3.0 %) (p < 0.001), and the aHR was 2.58 (95 % CI, 1.95-3.42; p < 0.001). Multivariable stratified analysis further verified significant associations of CKD with HBV in men of any age (aHR, 2.98; 95 % CI, 2.32–3.83, p < 0.001 for men aged <50 years; aHR, 1.58; 95 % CI, 1.31–1.91, p < 0.001 for men aged ≧50 years) and women under the age of 50 (aHR, 2.99; 95 % CI, 2.04–4.42, p < 0.001), but no significant association in women aged 50 or over.

Conclusion

Untreated chronic HBV infection is associated with increased risk of CKD. Hence, high-risk HBV-infected subjects should have targeted monitoring for the development of CKD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-015-0106-5) contains supplementary material, which is available to authorized users.

Comparison of renal safety and efficacy of telbivudine, entecavir and tenofovir treatment in chronic hepatitis B patients: real world experience

This study aims to assess the nephrotoxicity and efficacy of tenofovir disoproxil fumarate (tenofovir), telbivudine and entecavir. A retrospective study of 587 patients with chronic hepatitis B treated with tenofovir (n = 170), telbivudine (n = 184) and entecavir (n = 233) for at least 1 year. Renal function and efficacy were assessed. The estimated glomerular filtration rate (eGFR) decreased significantly in the tenofovir group after a mean of 17 months treatment (from 92.2 to 85.6 mL/min/1.73 m(2), p < 0.001), but increased in the telbivudine group after a mean of 32 months of treatment (from 86.1 to 95 mL/min/1.73 m(2), p < 0.001). There was no significant change in eGFR in the entecavir group after a mean of 44 months. By multivariate analysis, pre-existing renal insufficiency (p = 0.003), tenofovir (p = 0.007) and diuretic treatment (p = 0.001) were independent predictors for renal function deterioration. Cumulative virological breakthrough was 0% in tenofovir after 2 years, 3.4% in entecavir after 7 years and 22.9% in telbivudine after 5 years. Liver cirrhosis (p = 0.008) and virological breakthrough (p = 0.040) were independently associated with increased risk of hepatocellular carcinoma development. Tenofovir may lead to deterioration in renal function as assessed by serial eGFR measurements. Although telbivudine appeared to be associated with an improvement in eGFR, it was associated with high rates of virological breakthrough, which was an independent risk factor for HCC development. With low rates of virological breakthrough and preservation of renal function, entecavir could be the best choice among these three agents.

Effect of nucleoside and nucleotide analogues on renal function in patients with chronic hepatitis B virus monoinfection

BACKGROUND & AIMS

There is controversy regarding whether nucleos(t)ide analogues contribute to renal impairment in patients with chronic hepatitis B virus (HBV) infection. We analyzed changes in renal function in patients with chronic HBV infection and whether these were associated with treatment or comorbidities.

METHODS

We performed a longitudinal observational study to investigate factors associated with renal function in 214 patients (median age, 43 y; 69.2% men) with compensated chronic HBV monoinfection treated with 343 lines of nucleos(t)ide analogues (210 monotherapies, 133 combinations) between 1990 and 2012 (median time, 2.4 y) in France. A linear mixed-effect model was used to model variations of estimated glomerular filtration rate (eGFR, computed with the Chronic Kidney Disease Epidemiology Collaboration formula), adjusting for age, sex, geographic origin, initial liver fibrosis, level of HBV DNA, and an eGFR less than 90 mL/min/1.73 m(2).

RESULTS

The eGFR decreased in patients given adefovir dipivoxil as monotherapy or in a combination (P < .0001 and P < .002, respectively), and remained stable in patients given lamivudine, tenofovir disoproxil fumarate, or entecavir. The eGFR decreased in patients with a baseline eGFR of less than 90 mL/min/1.73 m2, regardless of treatment. The eGFR remained stable or increased, regardless of treatment, in patients with a baseline eGFR of 90 mL/min/1.73 m2 or greater and with an initial HBV DNA level of 100,000 IU/mL or greater. Patients born in areas of high endemicity of HBV were more prone to increases in eGFR with treatment.

CONCLUSIONS

In a real-life study, the eGFR remained stable or increased over time in patients with chronic HBV monoinfection with a baseline eGFR of 90 mL/min/1.73 m2 or higher and treated with tenofovir disoproxil fumarate or entecavir. Patients born in an area of high endemicity of HBV who had initial levels of HBV DNA of 100,000 IU/mL or greater were more likely to have increased eGFR with treatment.

Impact of nucleos(t)ide analogue combination therapy on the estimated glomerular filtration rate in patients with chronic hepatitis B

Monotherapy with telbivudine or adefovir can affect estimated the glomerular filtration rate (eGFR). However, only a few studies have assessed changes in eGFR in patients who have chronic hepatitis B (CHB) and are receiving nucleos(t)ide analogue (NA) combination therapy. In our study, we aimed to evaluate the effects of long-term NA combination therapy on eGFR in Chinese CHB patients. This retrospective study included 195 CHB patients. Patient subgroups included those treated with lamivudine plus adefovir (n = 73), telbivudine plus adefovir (n = 51), and entecavir plus adefovir (n = 35); untreated patients (n = 36) served as a control group. After an average follow-up duration of 24 months with combination therapy, analysis of changes in eGFR from baseline values, calculated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Modification of Diet in Renal Disease (MDRD) formulas, showed decrease by 11.08 and 18.34 mL/min (P < .001), respectively, in the lamivudine plus adefovir group; decrease by 3.73 and 10.04 mL/min (P = .012), respectively, in the entecavir plus adefovir group; and increase by 0.91 and 2.12 mL/min (P = .46), respectively, in the telbivudine plus adefovir group. The eGFR in the telbivudine plus adefovir group was similar to that for the untreated group. The eGFR decreases due to adefovir therapy could be rescued by adding telbivudine, and the eGFR increase due to telbivudine could be compromised by adding adefovir. Adefovir in combination with lamivudine or entecavir therapy was significantly associated with decreased eGFR, but telbivudine could rescue the eGFR decrease that results from adefovir treatment.

Antiviral treatment for chronic hepatitis B in renal transplant patients

Chronic hepatitis B infection is frequent in renal transplant patients. It negatively impacts long term outcomes reducing graft and patient survival. Current guidelines clearly define who needs treatment, when to start, what is the first line therapy, how to monitor treatment response, when to stop, and how patients must be controlled for its safety. There is some data showing a favorable safety and efficacy profile of nucleos(t)ide analogue (NUC) treatment in the renal transplant setting. Entecavir, a drug without major signs of nephrotoxicity, appears to be the first option for NUC naïve patients and tenofovir remains the preferred choice for patients with previous resistance to lamivudine or any other NUC. Renal transplant recipients under antiHBV therapy should be monitored for its efficacy against HBV but also for its safety with a close renal monitoring. Studies including a large number of patients with long term treatment and follow up are still needed to better demonstrate the safety and efficacy of newer NUCs in this population.

Differences in nephrotoxicity risk and renal effects among anti-viral therapies against hepatitis B

BACKGROUND

Results are conflicting with respect to the renal effects of anti-viral agents used for hepatitis B virus infection.

AIM

To compare short and long-term renal effects in real-life settings and to determine risk factors for renal impairment during treatment.

METHODS

2221 treatment-naïve patients were enrolled. Among these, 895 (302 lamivudine, 27 telbivudine, 282 entecavir, 273 tenofovir and 11 adefovir initiated patients) had 'repeated measures' of creatinine (baseline, 1st, 6th, 12th and 24th month of treatment). Telbivudine and adefovir groups were excluded from further analysis because of the low number of patients. We calculated the glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) formula at each time point. Hypophosphataemia was also recorded. Risk factors for renal impairment were analysed.

RESULTS

Tenofovir caused a decline in GFR at each time point when compared to baseline levels. However, lamivudine and entecavir did not change GFR. GFR-shifting from ≥90 to 60-89 mL/min/1.73 m(2) was comparable among groups. The proportion of patients whose baseline creatinine increased more than 25% was comparable among all anti-virals. GFR showed a decline in patients who switched from entecavir to tenofovir. One patient with compensated cirrhosis needed to change from tenofovir because of renal safety. Seven and three patients developed transient hypophosphataemia in the tenofovir and lamivudine groups, respectively.

CONCLUSIONS

Although tenofovir caused a decline in GFR, differences between the anti-viral agents do not appear to be so impressive. In patients with and without renal risk factors at baseline, there is no impact of anti-virals, including tenofovir.

Long-term treatment with tenofovir in Asian-American chronic hepatitis B patients is associated with abnormal renal phosphate handling

BACKGROUND

Increased risk of defective urinary phosphate reabsorption and osteoporosis has been reported in HIV and chronic hepatitis B (CHB) patients treated with tenofovir disoproxil fumarate (TDF).

AIMS

Goals of this study were to evaluate the prevalence of renal phosphate wasting and abnormal bone mineral density in CHB patients taking TDF compared to CHB patients treated with entecavir (ETV) and untreated CHB patients.

METHODS

This is a cross-sectional study of 146 consecutive Asian-American CHB patients who were treatment naïve (n = 60) or treated with either TDF (n = 42) or ETV (n = 44). Proximal tubular handling of phosphate was assessed by the maximal rate of tubular reabsorption of phosphate (TmPO4) divided by glomerular filtration rate (GFR) (TmPO4/GFR). Bone mineral density (BMD) was measured using dual X-ray absorptiometry.

RESULTS

TmPO4/GFR was similar among CHB patients treated with TDF compared to untreated patients and patients taking ETV. However, among patients treated with ≥18 months of TDF or ETV, prevalence of abnormal TmPO4/GFR was higher among patients treated with TDF compared to ETV (48.5 % (16/33) vs. 12.5 % (3/24), p = 0.005). Overall prevalence of osteoporosis in this cohort of CHB patients was 14 %, with no significant difference between the three groups. Renal phosphate handling did not correlate with osteoporosis.

CONCLUSIONS

Chronic hepatitis B patients treated with ≥18 months of TDF experienced an increased risk of proximal tubular dysfunction. TDF did not increase the risk of osteoporosis. Longitudinal studies are needed to confirm these findings.

Association between adefovir dipivoxil treatment and the risk of renal insufficiency in patients with chronic hepatitis B: A meta-analysis

Adefovir dipivoxil (ADV) is an effective antiviral drug against hepatitis B virus. The renal tolerance of ADV at the currently approved dose of 10 mg daily for the treatment of chronic hepatitis B (CHB) remains controversial. The present meta-analysis was therefore performed to evaluate the renal safety of ADV treatment in patients with CHB. Two independent investigators searched MEDLINE, Embase and China National Knowledge Infrastructure databases for eligible studies published in English or Chinese until June 1, 2014. The Peto odds ratios (Peto ORs) or the rates of each study were analyzed. Seven randomized controlled trials (RCTs), four cohort studies and six single-arm studies were identified. ADV treatment was not associated with a higher incidence of nephrotoxicity in RCTs [Peto OR, 1.781; 95% confidence interval (CI), 0.637-4.979; P=0.271] but appeared to increase nephrotoxicity significantly in cohort studies (Peto OR, 2.682; 95% CI, 1.470-4.894; P=0.001); the significant increase was further observed in CHB patients receiving long-term ADV treatment in cohort studies (Peto OR, 2.275; 95% CI, 1.127-4.593; P=0.022). The analysis based on single-arm studies showed that the rate of renal dysfunction in the ADV-treated patients was 10.6% (95% CI, 0.059-0.185); the subgroup analysis with the standard of createnine levels showed a lower rate (6.9%, 95% CI, 0.013-0.298) than those in the overall studies. In conclusion, although current evidence indicated a positive link between treatment with ADV in CHB patients and an increased risk of renal dysfunction, optimally designed studies are required for definitive conclusions.