Tenofovir-induced nephrotoxicity: incidence, mechanism, risk factors, prognosis and proposed agents for prevention

Tenofovir-associated Fanconi syndrome in liver transplant recipients with hepatitis B: A retrospective case series

Tenofovir-associated Fanconi syndrome (TAFS) is a proximal renal tubule disorder rarely reported in patients after liver transplantation (LT) for hepatitis B (HBV). In a retrospective review of 79 HBV-LT recipients, 8/66 (12.1%) on tenofovir post-LT developed TAFS. Primary laboratory findings were hypophosphatemia (100%) and proteinuria (87.5%). No patients required renal replacement therapy or died from TAFS. The majority (85.7%) of surviving patients achieved tubular recovery after stopping tenofovir (mean: 13 weeks). In conclusion, TAFS is likely underdiagnosed in LT recipients. Regular screening for hypophosphatemia, proteinuria, and glucosuria is recommended for HBV-LT recipients on tenofovir, as most responded well to discontinuation.

Population Pharmacokinetic Simulations for Dose Optimization of Tenofovir Disoproxil Fumarate in HIV-Infected Patients with Moderate-to-Severe Renal Impairment

Tenofovir disoproxil fumarate (TDF) requires dosage adjustments from the standard 300 mg once daily to every 48-96 h for moderate-to-severe renal impairment to avoid excessive exposure. However, this extended interval can lead to variable drug exposure and inconvenience. This study aimed to utilize the population pharmacokinetic (PPK) models to optimize TDF dosing regimens for HIV-infected patients with renal impairment. A systematic literature search was conducted across PubMed, Cochrane Library, and Scopus databases to identify relevant PPK studies of TDF in HIV-infected patients. From the included studies, the PPK models and associated parameters were extracted. Monte Carlo simulations (n = 2000) were performed to generate concentration-time profiles and derive PK parameters compared against reference ranges. For moderate renal impairment, the TDF 150 mg once-daily regimen achieved cumulative exposure comparable to the approved 300 mg every-other-day regimen. In severe renal impairment, TDF 75-100 mg administered once daily provided similar cumulative exposure as 300 mg every 72-96 h regimen while maintaining daily exposure comparable to the standard dose in patients with normal renal function. The approved extended dosing intervals of 72-96 h exhibited high drug exposure variability, initially resulting in supratherapeutic levels followed by suboptimal levels preceding the subsequent dose administration. In conclusion, administering smaller once-daily doses of TDF maintains consistent daily drug exposure comparable to the standard dose in patients with normal renal function while reducing variability in drug exposure, potentially mitigating the risk of nephrotoxicity. However, additional clinical studies are required to confirm these findings.

Chronic kidney disease among people living with HIV on TDF based regimen: A systematic review and meta-analysis

INTRODUCTION

Chronic kidney disease is a major public health concern among people living with human immunodeficiency virus (PLWHIV) who are taking tenofovir disoproxil fumarate-based regimen. Despite the available evidence showing a high prevalence of CKD in this population, comprehensive pooled estimate of CKD among PLWHIV receiving TDF based regimen across the globe is lacking. Hence, the present systematic review aimed to provide a global pooled prevalence estimate of CKD.

METHOD

We conducted a systematic review of literatures published between January 2000 and May 2024. Articles and grey literature were searched from the following databases and search engine: PubMed, EMBASE, Scopus, Web of science, The Cumulative Index to Nursing and Allied Health Literature (CINHAL), and Google Scholar. We included eligible studies that report magnitude of CKD in TDF based regimen. We executed the pooled CKD, subgroup analysis, and funnel plot using random effect model. All statistical analysis including sensitivity analysis were made using Stata 17 software.

RESULTS

Sixty-nine studies with 88299 participants included in this meta-analysis. The pooled prevalence of CKD was 7% (95% CI:6-8). CD4 count less than 200 copies per milliliter, and being female were associated with CKD.

CONCLUSION

We concluded that the magnitude of CKD across the globe is high in people living with HIV who have received TDF based regimen. Early identification of CKD by considering regular renal function monitoring, and risk factors especially low CD4 count, and female gender at birth are essential.

TRIAL REGISTRATION

The protocol has been prospectively registered with PROSPERO ((CRD42020136813).

Urogenital Manifestations in Mpox (Monkeypox) Infection: A Comprehensive Review of Epidemiology, Pathogenesis, and Therapeutic Approaches

Monkeypox (mpox), caused by mpox virus (MPXV) infection, reemerged in 2022 and still raises concerns globally. Abundant clinical data indicate that mpox is a sexually transmitted infection and that the urogenital system is the most frequently involved system in mpox, which deserves more attention. Penile lesions are the most common presentation, followed by urethritis. Acute urine retention and acute kidney injury are relatively rare but also highly crucial. Currently, the majority of the urogenital lesions are considered complications secondary to MPXV infection and the common immunosuppression in mpox patients. However, such viewpoints should be treated carefully due to the lack of understanding of the basic mpox pathology. Here, we briefly and comprehensively review the current evidence concerning urogenital lesions caused by mpox, including epidemiology, clinical features, pathogenesis, and therapeutic approaches to provide a preliminary reference for clinicians in future clinical practice.

Tenofovir induced Fanconi syndrome in a middle age African female from Kenya, East Africa: Case report and brief literature review

This case presentation highlights the need to routinely monitor renal function in patients on Tenofovir Disoproxil Fumarate (TDF) due to its side effect of proximal tubule dysfunction.

Abstract

This is a case presentation of a 50-year-old African female who had been on a Tenofovir based regimen for 12 years and developed Fanconi syndrome. She recovered after discontinuation of the Tenofovir Disoproxil Fumarate (TDF).

Effects of Prolonged Administration of Tenofovir Disoproxil Fumarate-Containing Antiviral Regimen on Renal Function in Low-Risk of Kidney Injury HIV Patients

This study intended to investigate the impact of long-term tenofovir fumarate (TDF) antiviral regimen on renal function in human immunodeficiency virus (HIV)-infected patients with low-risk of kidney injury. The observational study involving 100 HIV-infected patients without underlying diseases who achieved virological suppression and immunological recovery after sustained antiviral regimen of TDF+ lamivudine+ efavirenz (TLE) for 3.19 years. Renal function, including estimated glomerular filtration rate (eGFR), blood and urine β2 microglobulin, and other parameters, was assessed every 3 months over a period of 2.5 years. The eGFR showed a slight increasement from 116.0 at month 0 to 119.7 at month 30. Blood β2 microglobulin increased from 2.02 mg/L at month 0 to 2.77 mg/L at month 30. Compared to month 0, the difference in blood β2 microglobulin was statistically significant at month 6 and months 12-30 (P < .05). The incidence of proximal renal tubular dysfunction fluctuated from 2% at month 0 to 2.5% at month 30. The urine β2 microglobulin fluctuated from 0.5 (0.3-1.1) to 0.8 (0.5-1.35) mg/L at months 18-30, which was higher than 0.41 (0.18-1.1) mg/L at month 0 (P < .05). The abnormal concentration proportion of urine β2 microglobulin fluctuated from 72.7% to 81.3% at months 18-30, which was higher than the proportion of 57.0% at month 0. The abnormal proportion of blood β2 microglobulin, urine β2 microglobulin, and proximal renal tubular dysfunction were not correlated with eGFR (r1 = 0.119, r2 = -0.008, r3 = -0.165, P > .05). Long-term TDF antiviral regimen in low-risk of kidney injury HIV-infected patients may lead to damage in the proximal renal tubules and glomeruli. Blood and urine β2 microglobulin levels may be helpful in screening for renal dysfunction.

From Rare Disorders of Kidney Tubules to Acute Renal Injury: Progress and Prospective

Background

Acute kidney injury (AKI) is a severe condition marked by rapid renal function deterioration and elevated mortality, with traditional biomarkers lacking sensitivity and specificity. Rare tubulointerstitial diseases encompass a spectrum of disorders, primarily including monogenic diseases, immune-related conditions, and drug-induced tubulointerstitial diseases. The clinical manifestations vary from electrolyte and acid-base imbalances to kidney function insufficiency, which is associated with AKI in up to 20% of cases. Evidence indicated that rare tubulointerstitial diseases might provide new conceptual insights and perspectives for novel biomarkers and potential therapeutic strategies for AKI.

Summary

Autosomal dominant tubulointerstitial kidney disease (ADTKD) and Fanconi syndrome (FS) are rare tubulointerstitial diseases. In ADTKD, UMOD and REN are closely related to AKI by affecting oxidative stress and tubuloglomerular feedback, which provide potential new biomarkers for AKI. Both rare tubulointerstitial diseases and AKI share etiologies and treatment responses. From the mechanism standpoint, rare tubulointerstitial diseases and AKI involve tubular transporter injury, initially manifesting as tubular dysfunction in tubulointerstitial disorder and progressing to AKI because of the programmed cell death with apoptosis, pyroptosis, or necroptosis of proximal tubule cells. Additionally, mitochondrial dysfunction has been identified as a common mechanism in both tubulointerstitial diseases and AKI induced by drugs, pSS, or monoclonal diseases. In the end, both AKI and FS patients and animal models responded well to the therapy of the primary diseases.

Key Messages

In this review, we describe an overview of ADTKD and FS to identify their associations with AKI. Mitochondrial dysfunction contributes to rare tubulointerstitial diseases and AKI, which might provide a potential therapeutic target.

Tenofovir-Induced Fanconi Syndrome Presenting with Life-Threatening Hypokalemia: Review of the Literature and Recommendations for Early Detection

Tenofovir disoproxil fumarate (TDF) is a nucleotide reverse transcriptase inhibitor that has been widely used for the treatment of patients with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) infections. Despite the excellent safety records of this regimen, a few cases of acute renal failure and Fanconi syndrome have been reported among HIV patients exposed to TDF. However, in the HBV monoinfection scenario, only five cases of TDF-associated Fanconi syndrome have been reported thus far, two of them providing a confirmatory kidney biopsy. Here, we describe the case of a 68-year-old woman with chronic hepatitis B (CHB) who developed TDF-induced Fanconi syndrome that reverted after TDF withdrawal from tenofovir alafenamide. Though the overall risk of TDF-associated severe renal toxicity in HBV patients appears to be negligible, both glomerular and tubular functions should be monitored in patients exposed to TDF.

Broadening access to tenofovir alafenamide for the treatment and prevention of HIV-1 infection

INTRODUCTION

Tenofovir alafenamide (TAF), a prodrug of tenofovir, achieves higher intracellular concentrations of tenofovir-diphosphate and 90% lower plasma concentrations of tenofovir compared to tenofovir disoproxil fumarate (TDF). TAF is associated with improved renal and bone safety outcomes.

AREAS COVERED

We review the efficacy and safety of TAF-containing regimens in adults and pediatrics. We highlight safety data during pregnancy, drug interactions during co-administration with tuberculosis treatment, and critical knowledge gaps to be addressed for the successful implementation of TAF in low- and middle-income countries. We performed a search on MEDLINE PubMed and conference websites for relevant articles published from January 2010 to March 2023.

EXPERT OPINION

Current evidence demonstrates that TAF has similar efficacy and tolerability, superior bone and renal safety, and higher rates of dyslipidemia and weight gain, compared with TDF. However, there are several knowledge gaps, in specific sub-populations, that require action. Emerging data suggests that TAF is safe during pregnancy, although fuller safety data to support TAF use in pregnancy is needed. Similarly, there is a lack of evidence that TAF can be used in combination with rifamycin-based tuberculosis treatment in PWH and TB. Further studies are needed to fill knowledge gaps and support the wider rollout of TAF.

Week 96 Results of Switching from Tenofovir Disoproxil Fumarate-Based Antiretroviral Therapy to Coformulated Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir Alafenamide among HIV/Hepatitis B Virus-Coinfected Patients

Data regarding the durability of tenofovir alafenamide (TAF)-containing antiretroviral therapy (ART) in maintaining hepatitis B virus (HBV) viral suppression among HIV/HBV-coinfected patients are limited. Between February and October 2018, 274 HIV/HBV-coinfected participants who had achieved HIV RNA of <50 copies/mL with tenofovir disoproxil fumarate (TDF)-containing ART and switched to elvitegravir/cobicistat/emtricitabine/TAF were prospectively enrolled. Serial plasma HIV and HBV viral loads, HBV and hepatitis D virus (HDV) serology, renal parameters, metabolic profiles, and bone mineral density (BMD) were assessed through 96 weeks. At baseline and weeks 48, 72, and 96, 5.8%, 5.1%, 5.8%, and 5.1% of the participants had plasma HBV DNA of ≥20 IU/mL, and 0%, 0.7%, 1.5%, and 2.2% had HIV RNA of ≥50 copies/mL, respectively. Hepatitis B surface antigen (HBsAg) loss occurred in 1.5% of 274 participants, and hepatitis B e-antigen (HBeAg) loss or seroconversion occurred in 14.3% of 35 HBeAg-positive participants. Compared with baseline, the median urine protein-to-creatinine ratio (79 versus 63 mg/g, P < 0.001) and β2-microglobulin-to-creatinine ratio (165 versus 83 μg/g, P < 0.001) continued to decrease at week 96. BMD of the spine and hip slightly increased (mean change, +0.9% and +0.5%, respectively). The median triglycerides, total cholesterol, low-density lipoprotein (LDL)-cholesterol and high-density lipoprotein (HDL)-cholesterol increased from baseline to week 96 (116 versus 141, 166 versus 190, 99 versus 117, and 42 versus 47 mg/dL, respectively; all P < 0.001), and most of the increases occurred in the first 48 weeks of the switch. Our study showed that switching from TDF-containing ART to elvitegravir/cobicistat/emtricitabine/TAF maintained HBV and HIV viral suppression through 96 weeks among HIV/HBV-coinfected patients. Proteinuria continued to improve, while fasting lipids increased and BMD stabilized at 96 weeks after the switch. IMPORTANCE Elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide as a maintenance therapy showed durable and high rates of viral suppression for HIV/HBV-coinfected patients, with only 5.1% and 2.2% of patients having HBV DNA of ≥20 IU/mL and HIV RNA of ≥50 copies/mL, respectively, at 96 weeks. Our study fills the data gap on the long-term clinical effectiveness of tenofovir alafenamide-containing antiretroviral therapy in people living with HIV who have HBV coinfection.

Efficacy and safety of long-term postpartum antiviral therapy in hepatitis B virus-infected mothers receiving prophylactic tenofovir disoproxil fumarate treatment

OBJECTIVES

This study aimed to evaluate the efficacy and safety of long-term postpartum tenofovir disoproxil fumarate (TDF) therapy in hepatitis B virus (HBV)-infected mothers with high viral load.

METHODS

In this retrospective cohort study, HBV-infected mothers with HBV DNA>2 × 10 5  IU/mL who initiated TDF prophylaxis treatment during pregnancy were divided into TDF continuation and discontinuation groups according to whether they stopped TDF treatment within 3 months after birth or not. Virological and biochemical markers were collected before TDF treatment, antepartum and postpartum.

RESULTS

In 131 women followed for a median of 18 months postpartum, alanine aminotransferase (ALT) abnormality rate was significantly lower in TDF continuation group vs. discontinuation group (39.4% vs. 56.9%, P  = 0.045), and continuous TDF therapy in postpartum was independently associated with lower risk of ALT flares [OR = 0.308, 95% confidence interval (CI), 0.128-0.742; P  = 0.009]. Long-term postpartum TDF treatment can promote the decline of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) levels, but the HBeAg seroconversion rate in two groups was not significant (15.5% vs. 11.7%, P  = 0.541). There were no statistical differences in bone metabolism markers between two groups ( P  > 0.05). Compared with the TDF discontinuation group, TDF continuation group had a significantly lower estimated glomerular filtration rate level and higher creatinine level in postpartum but within normal ranges ( P  < 0.05).

CONCLUSIONS

For pregnant women who received prophylactic TDF treatment, long-term TDF therapy continued in postpartum can reduce the risk of ALT flares and promote the rapid decline of HBeAg and HBsAg levels.

Long-Term Evaluation of Changes in Kidney Function after Switching from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in Patients Living with HIV

Tenofovir is one of the most widely used medications for HIV treatment and is administered as either tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide (TAF). Use of TAF is preferred as it is associated with fewer negative impacts on renal function; however, long-term follow-up beyond 96 weeks is limited. A retrospective chart review of patients ≥18 years who received TDF-containing anti-retroviral therapy (ART) for ≥6 months and then switched to a TAF-containing regimen between 1 December 2015 and 1 January 2020 is presented. The primary objective was to evaluate changes in kidney function as measured by eGFR and Scr. The secondary objective was to evaluate changes in lipids. Among the 142 patients identified, the median age was 66 years old with a median follow-up of 3.6 years. The change in kidney function was a median increase in Scr of 0.1 mg/dL and a decrease in eGFR of -8 mL/min/1.73 m². The change in lipid panels at the end of the medication use evaluation endpoint was a decrease in total cholesterol, LDL, HDL, and triglycerides of -2.5, -0.1, -0.6, and -9 mmol/L, respectively. There was no clinically meaningful difference in kidney function as measured by eGFR or Scr, nor was there any clinically meaningful difference in lipid panels in patients switched from TDF to TAF-containing ART. Our observations suggest that the favorable impact of TAF on kidney function is sustained for at least 44 months after conversion from TDF.

One hundred and ninety-two weeks treatment of entecavir maleate for Chinese chronic hepatitis B predominantly genotyped B or C

BACKGROUND

Entecavir (ETV) is a potent and selective nucleotide analog with significant activity against hepatitis B virus (HBV). ETV maleate is a derivative compound of ETV and was reported to have an efficacy and safety profile that is comparable to ETV (Baraclude) when used in Chinese patients with chronic hepatitis B (CHB) in phase III clinical trials (Clinical Trials.gov number, NCT01926288) at weeks 48, 96, and 144.

AIM

To investigate the antiviral potency and safety of ETV maleate at week 192 in Chinese CHB patients predominantly genotyped B or C.

METHODS

In this double-blind study, we randomly assigned patients to receive 0.5 mg/d ETV (Group A) or ETV maleate (Group B) (ratio, 1:1), each with a placebo tablet for 48 wk. Then, all patients received open-label treatment with 0.5 mg/d ETV maleate starting at week 49. The primary efficacy endpoint was the reduction in HBV DNA levels from baseline. Secondary endpoints included the proportion of patients with undetectable HBV DNA (< 20 IU/mL), serologic response, serum alanine aminotransferase (ALT) normalization and development of resistance mutations.

RESULTS

Two hundred eighteen patients who were hepatitis B e antigen (HBeAg) positive and 57 who were HBeAg negative were analyzed and predominantly presented with genotype B (49.82%) or C (48.73%). For the HBeAg-positive CHB patients, the mean HBV DNA level decrease (6.61 Log10 IU/mL vs 6.69 Log10 IU/mL, P > 0.05), viral suppression with HBV DNA < 20 IU/mL (83.33% vs 79.17%, P > 0.05) and HBeAg seroconversion (28.77% vs 20.00%, P > 0.05) occurred similarly between Groups A and B at week 192. However, there was a significant difference in the proportion of patients with normal ALT levels (91.14% vs 78.38%, P < 0.05). For the HBeAg-negative CHB patients, no significant difference was found between Groups A and B at week 192 in terms of reductions in HBV DNA levels from baseline (6.05 Log10 IU/mL vs 6.03 Log10 IU/mL, P > 0.05), percentages of patients who achieved undetectable HBV DNA (100% vs 100%, P > 0.05) and rates of ALT normalization (95.65% vs 100.00%, P > 0.05). Safety and adverse event profiles were similar between Groups A and B. Two HBeAg-positive patients in Group A and 5 in Group B developed genotypic resistance to ETV.

CONCLUSION

Long-term ETV maleate treatment for up to 192 wk is effective and safe in Chinese CHB patients predominantly genotyped as B or C.

The Potential of Moringa oleifera to Ameliorate HAART-Induced Pathophysiological Complications

Highly active antiretroviral therapy (HAART) comprises a combination of two or three antiretroviral (ARV) drugs that are administered together in a single tablet. These drugs target different steps within the human immunodeficiency virus (HIV) life cycle, providing either a synergistic or additive antiviral effect; this enhances the efficiency in which viral replication is suppressed. HIV cannot be completely eliminated, making HAART a lifetime treatment. With long-term HAART usage, an increasing number of patients experience a broadening array of complications, and this significantly affects their quality of life, despite cautious use. The mechanism through which ARV drugs induce toxicity is associated with metabolic complications such as mitochondrial dysfunction, oxidative stress, and inflammation. To address this, it is necessary to improve ARV drug formulation without compromising its efficacy; alternatively, safe supplementary medicine may be a suitable solution. The medicinal plant Moringa oleifera (MO) is considered one of the most important sources of novel nutritionally and pharmacologically active compounds that have been shown to prevent and treat various diseases. MO leaves are rich in polyphenols, vitamins, minerals, and tannins; studies have confirmed the therapeutic properties of MO. MO leaves provide powerful antioxidants, scavenge free radicals, promote carbohydrate metabolism, and repair DNA. MO also induces anti-inflammatory, hepatoprotective, anti-proliferative, and anti-mutagenic effects. Therefore, MO can be a source of affordable and safe supplement therapy for HAART-induced toxicity. This review highlights the potential of MO leaves to protect against HAART-induced toxicity in HIV patients.

Comparison of renal safety and bone mineral density of tenofovir and entecavir in patients with chronic hepatitis B: A Systematic Review and Meta-analysis

OBJECTIVE

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are recommended as first-line treatments for chronic hepatitis B (CHB). However, the safety of these two drugs remains controversial. This study aims to evaluate and compare renal function and bone mineral density in CHB patients who took TDF or ETV.

METHODS

The electronic databases of the Cochrane Library, PubMed, and Embase were searched. The key words were: "CHB," "tenofovir," and "entecavir". Heterogeneity and subgroups were analyzed.

RESULTS

16 studies met the inclusion criteria. There was no significant difference in serum creatinine levels between the TDF and the ETV group. There was a significant standardized mean difference in serum estimated glomerular filtration rate (eGFR) between months (12 months: SMD [95%CI] = -0.07 [-0.12, -0.01]; 18-24 months: SMD [95%CI]=-0.11[-0.17],-0.05]), but no significant difference emerged in the long-term drug use for over 24 months. There was no significant difference in the incidence of osteopenia/osteoporosis (I²=41%, RR [95%CI]=1.29[0.93,1.77], p=0.13>0.05).

CONCLUSIONS

Compared with the ETV group, a greater reduction in eGFR and serum phosphorus levels was observed in the TDF group. There was no significant difference in the incidence of osteopenia/osteoporosis between the two groups.

Treatment with β-blocker nebivolol ameliorates oxidative stress and endothelial dysfunction in tenofovir-induced nephrotoxicity in rats

Background

Tenofovir disoproxil fumarate (TDF), a widely prescribed component in antiretroviral regimens, has been associated with nephrotoxicity. Nebivolol is a third generation selective β-1 adrenergic receptor blocker and may protect renal structure and function through the suppression of oxidative stress and enhancement of nitric oxide (NO) synthesis. We aimed to investigate whether nebivolol could be an effective therapeutic strategy to mitigate tenofovir-induced nephrotoxicity.

Methods

We allocated Wistar rats to four groups: control (C), received a standard diet for 30 days; NBV, received a standard diet for 30 days added with nebivolol (100 mg/kg food) in the last 15 days; TDF, received a standard diet added with tenofovir (300 mg/kg food) for 30 days; and TDF+NBV, received a standard diet added with tenofovir for 30 days and nebivolol in the last 15 days.

Results

Long-term exposure to tenofovir led to impaired renal function, induced hypertension, endothelial dysfunction and oxidative stress. Nebivolol treatment partially recovered glomerular filtration rate, improved renal injury, normalized blood pressure and attenuated renal vasoconstriction. Administration of nebivolol contributed to reductions in asymmetric dimethylarginine (ADMA) levels as well as increases in endothelial nitric oxide sintase (eNOS) accompanied by renin-angiotensin-aldosterone system downregulation and decreases in macrophage and T-cells infiltrate. Furthermore, nebivolol was responsible for the maintenance of the adequate balance of thiobarbituric acid reactive substances (TBARS) and glutathione (GSH) levels and it was associated with reductions in NADPH oxidase (NOX) subunits.

Conclusion

Nebivolol holds multifaceted actions that promote an advantageous option to slow the progression of kidney injury in tenofovir-induced nephrotoxicity.

Long-term renal safety between patients with chronic hepatitis B receiving tenofovir vs. entecavir therapy: A multicenter study

Renal safety is a critical issue in chronic hepatitis B (CHB) patients receiving long-term entecavir (ETV) or tenofovir disofuroxil fumarate (TDF) therapy. We investigated their effects on estimated glomerular filtration rate (eGFR). Treatment-naive CHB patients receiving ETV or TDF for ≥1 year were recruited. The eGFR was assessed using the Chronic Kidney Disease Epidemiology Collaboration equation. We calculated average annual percent change (AAPC) in eGFR using Joinpoint regression. At the beginning of the observation, the ETV group had more unfavorable conditions than the TDF group: lower eGFR and higher FIB-4 and APRI than the TDF group (all p < .001). After 6 years of antiviral therapy, the mean eGFR in the ETV group (n = 1793) was maintained (96.0 at first year to 95.6 ml/min/1.73 m2 at sixth year; AAPC -0.09%; p = .322), whereas that in the TDF group (n = 1240) significantly decreased annually (101.9 at first year to 96.9 ml/min/1.73 m2 at sixth year; AAPC -0.88%; p < .001). Notably, in the TDF group, even patients without diabetes (AAPC -0.80%; p = 0.001) or hypertension (AAPC -0.87%; p = .001) experienced significant decrease in eGFR. Expectably, accompanying diabetes (AAPC -1.59%; p = .011) or hypertension (AAPC -1.00%; p = .002) tended to accelerate eGFR decrease. TDF treatment (odds ratio 1.66, p < .001), along with eGFR<60 ml/min/1.73 m2 , serum albumin<3.5 mg/dl, and hypertension, were independently associated with ongoing renal dysfunction, defined as a negative slope of the mean eGFR change. In conclusion, compared with ETV, long-term TDF treatment induced slow, but progressive renal dysfunction. Although the annual eGFR change by TDF was small, careful monitoring is necessary, especially in patients requiring life-long therapy.

Dissecting Drug-Induced Cytotoxicity and Metabolic Dysfunction in Conditionally Immortalized Human Proximal Tubule Cells

Fourteen to 26 percent of all hospitalized cases of acute kidney injury are explained by drug-induced toxicity, emphasizing the importance of proper strategies to pre-clinically assess renal toxicity. The MTT assay is widely used as a measure of cell viability, but largely depends on cellular metabolic activity. Consequently, MTT as a single assay may not be the best way to assess cytotoxicity of compounds that reduce mitochondrial function and cellular metabolic activity without directly affecting cell viability. Accordingly, we aim to highlight the limitations of MTT alone in assessing renal toxicity of compounds that interfere with metabolic activity. Therefore, we compared toxic effects observed by MTT with a fluorescent assay that determines compromised plasma membrane permeability. Exposure of proximal tubule epithelial cells to nephrotoxic compounds reduced cellular metabolic activity concentration- and time-dependently. We show that compared to our fluorescence-based approach, assessment of cellular metabolic activity by means of MTT provides a composite readout of cell death and metabolic impairment. An approach independent of cellular metabolism is thus preferable when assessing cytotoxicity of compounds that induce metabolic dysfunction. Moreover, combining both assays during drug development enables a first discrimination between compounds having a direct or indirect mitochondrial toxic potential.

Kidney function and daily emtricitabine/tenofovir disoproxil fumarate pre-exposure prophylaxis against HIV: results from the real-life multicentric demonstrative project PrEP Brazil

Background

Pre-Exposure Prophylaxis (PrEP) has demonstrated efficacy in the reduction of sexually transmitted HIV infections. The prolonged use of tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) co-formulation (TDF/FTC), however, may result in augmented risk of renal toxicity. We aimed to evaluate changes in the estimated Glomerular Filtration Rate (eGFR) in a real-world population setting of participants enrolled in PrEP Brazil, a 48-week prospective, open-label, demonstration study to assess the feasibility of daily oral TDF/FTC used by men who have sex with men and transgender women at high-risk of HIV infection, all over 18 years old.

Methods

Kidney function was assessed by serial measurement of serum creatinine and eGFR with the Modification of Diet in Renal Disease Study (MDRD) formula on weeks 4, 12, 24, 36 and 48. Adherence to PrEP was assessed by dosing TDF concentration in dried blood spots at weeks 4 and 48, measured by liquid chromatography-mass spectrometry or mass spectrometry.

Results

Of 392 participants completing the 48-week follow-up protocol with TDF blood detectable levels and eGFR measures, 43.1% were young adults, of Caucasian ethnic background (57.9%), with BMI below 30 kg/m², without arterial hypertension. At screening, median eGFR was 93.0 mL/min/1.73 m². At week 4 follow-up, 90 (23% of the study population) participants presented reductions in eGFR greater than 10 mL/min/1.73 m² as compared to baseline eGFR, some as large as 59 mL/min/1.73 m², but with no clinical outcomes (adverse events and renal adverse events) severe enough to demand TDF/FTC discontinuation. A negative relationship was observed between TDF blood levels and eGFR at weeks 4 (r = − 0.005; p < 0.01) and 48 (r = − 0.006; p < 0.01).

Conclusions

These results suggest that the renal function profile in individuals on TDF/FTC may be assessed on week 4 and then only annually, allowing a more flexible medical follow-up in primary care centers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12981-022-00437-4.

Efficacy and safety of tenofovir disoproxil fumarate and tenofovir alafenamide fumarate in preventing HBV vertical transmission of high maternal viral load

BACKGROUND

Hepatitis B virus (HBV) infection is a significant global health problem and > 42-52% of patients are infected during perinatal period. Tenofovir alafenamide fumarate (TAF) and tenofovir disoproxil fumarate (TDF) have been widely recognized as the main compounds used for antiviral treatment of hepatitis B. The present study evaluated the efficacy and safety of TAF in reducing HBV vertical transmission.

METHODS

A total of 72 pregnant women, who met the inclusion criteria, were randomly divided into the TDF (300 mg/day, n = 36) and TAF (25 mg/day, n = 36) groups. Clinical and laboratory data were analyzed and compared between the two groups.

RESULTS

No significant differences in alanine aminotransferase, total bilirubin, blood creatinine and blood urea nitrogen levels were noted between the two groups after treatment. The serum HBV DNA viral load and hepatitis B e antigen (HBeAg) levels of the two groups were significantly decreased following treatment, whereas the difference between the two groups was not statistically significant. The levels of urine retinol-binding protein and β2-microglobulin had no significant change after TAF treatment (p > 0.05), but increased significantly after TDF treatment (p < 0.05). All drug concentrations were undetectable in umbilical cord blood (UCB) and breast milk samples of the TAF group, while the drug concentration of UCB and breast milk samples in the TDF group was 2.98 ± 1.44 and 19.16 ± 15.26 ng/ml, respectively. All infants were tested negative for serum hepatitis B surface antigen, HBV DNA, and HBeAg.

CONCLUSIONS

Both TAF and TDF effectively block the mother-to-child transmission of hepatitis B. TAF was superior to TDF with regard to renal safety and breastfeeding.

Prognostic model for nephrotoxicity among HIV-positive Zambian adults receiving tenofovir disoproxil fumarate-based antiretroviral therapy

Persons living with HIV (PLWH) receiving tenofovir disoproxil fumarate (TDF)-based antiretroviral therapy (ART) risk suffering TDF-associated nephrotoxicity (TDFAN). TDFAN can result in short- and long-term morbidity, including permanent loss of kidney function, chronic kidney disease (CKD), and end-stage kidney disease (ESKD) requiring dialysis. Currently, there is no model to predict this risk or discern which patients to initiate TDF-based therapy. Consequently, some patients suffer TDFAN within the first few months of initiating therapy before switching to another suitable antiretroviral or a lower dose of TDF. In a prospective observational cohort study of adult Zambian PLWH, we modelled the risk for TDFAN before initiating therapy to identify individuals at high risk for experiencing AKI after initiating TDF-based therapy. We enrolled 205 HIV-positive, ART-naïve adults initiating TDF-based therapy followed for a median of 3.4 months for TDFAN at the Adult Infectious Disease Research Centre (AIDC) in Lusaka, Zambia. We defined TDFAN as meeting any of these acute kidney disease (AKD) criteria: 1) An episode of estimated glomerular filtration rate (eGFR)< 60ml/ min/1.73m2 within 3 months, 2) reduced eGFR by> 35% within 3 months or 3) increased serum creatinine by> 50% within 3 months. A total of 45 participants (22%) developed acute kidney disease (AKD) after TDF-based therapy. The development of AKD within the first 3 months of commencing TDF-based therapy was associated with an increase in baseline serum creatinine, age, baseline eGFR and female sex. We concluded that baseline characteristics and baseline renal function biomarkers predicted the risk for AKD within the first 3-months of TDF-based therapy.

Tenofovir Disoproxil Fumarate-Associated Renal Dysfunction Among Adult People Living with HIV at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia, 2019: A Comparative Retrospective Cohort Study

BACKGROUND

The use of tenofovir disoproxil fumarate (TDF) has been reported to be a significant contributor to renal dysfunction. However, patients in Ethiopia may be different than in other parts of the world, and findings from such studies may not apply in this setting.

OBJECTIVE

This study aimed to assess TDF-associated renal dysfunction among adult people living with HIV (PLHIV) at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia.

METHODS

This retrospective cohort study included adult PLHIV between January 2015 and June 2019. The Chronic Kidney Disease Epidemiology (CKD-EPI) equation was used to estimate glomerular filtration rate (eGFR). Renal dysfunction was defined as eGFR <60 mL/min/1.73 m2. Data were entered into Epi Info™ 7 and analyzed by using SPSS® software version 20. The Kaplan-Meier method was used to estimate the survival curves. Cox proportional hazards models were used to identify predictors of renal dysfunction using a 95% confidence interval and p-value ≤ 0.05 as a statistical significance.

RESULTS

Out of 400 participants, 200 were TDF-based ART groups, and 200 were non-TDF-based ART groups. The incidence of renal dysfunction of TDF and the non-TDF group was 28.31 per 100 person-years (PYs) and 12.53 per 100 PYs, respectively. Adult PLHIV taking TDF-based regimens were 1.70 (adjusted HR = 1.70; 95% CI = 1.02-2.82) times at higher risk of renal dysfunction than non-TDF-based regimens. Age ≥55, diabetes mellitus, concurrent nephrotoxic drug use, and combined use of ritonavir-boosted protease inhibitors were also associated significantly with renal dysfunction.

CONCLUSION

The incidence rate of renal dysfunction among TDF users is higher than non-TDF users. Exposure to TDF is a significant risk of renal dysfunction in adult PLHIV. Clinicians should regularly monitor the renal function of adult PLHIV who are taking TDF.

The effects of vitamin E on colistin-induced nephrotoxicity in treatment of drug-resistant gram-negative bacterial infections: A randomized clinical trial

INTRODUCTION

Nephrotoxicity remains a major long-standing concern for colistin, and it is critical to find agents that can prevent it. The present study aims to investigate the effect of vitamin E on the prevention of colistin-induced nephrotoxicity based on its antioxidant and free radical scavenging properties.

METHODS

A randomized clinical trial was designed for 52 patients taking colistin. These patients were categorized into two groups of equal size, receiving colistin or colistin plus vitamin E (α-Tocopherol). Vitamin E with doses of 400 units was administrated daily either orally or by a nasogastric tube if needed. The incidence of Acute Kidney Injury (AKI) and its duration was recorded based on RIFLE criteria.

RESULTS

The Incidence of AKI based on RIFLE criteria was 42.3% and 46.2% in intervention and control groups, respectively. The analysis showed no significant difference in the prevalence of AKI for the two groups (P = 0.78). There was no significant difference in the duration of AKI neither (P = 0.83).

CONCLUSION

Although vitamin E is a powerful biological antioxidant, the effects of Vitamin E prophylaxis on colistin-induced nephrotoxicity was not taken into consideration in this study.

Weight and body mass index increase after switch from tenofovir disoproxil fumarate to tenofovir alafenamide fumarate-containing treatment in an antiretroviral therapy-experienced group

Tenofovir alafenamide fumarate (TAF) is an alternative to tenofovir disoproxil fumarate (TDF). Currently, TAF is increasingly being used because of its non-inferior antiviral properties, lower risk of nephrotoxicity, and lower decrease in bone mineral density than TDF. There is growing evidence of unfavorable effects of TAF on weight and body mass index (BMI) in antiretroviral therapy (ART)-experienced patients treated with TAF-based ART. The aim of this study was to evaluate whether switching from TDF-containing to TAF-containing ART is associated with an increase in BMI and body weight in ART-experienced patients. Two study groups were established: 32 patients who switched from TDF to TAF only and 68 patients who switched from TDF to TAF along with changes to other components of the ART regimen. Significant weight gain and BMI increase was observed during the first year after initiation of TAF-containing ART regimens in both groups (mean change +1.91 kg and +0.61 kg/m2 in the first group and +1.50 kg and +0.49 kg/m² in the second group). During the second year of TAF-based treatment, a sustained trend of body weight and BMI increase was noted only in the second group (mean change +1.46 kg, + 0.46 kg/m²). Analysis of body weight changes in certain subpopulations from the second group (selected based on patients' baseline characteristics) revealed a significant weight gain within two years after the switch in patients over 50 years old and in those whose ART had lasted longer than 10 years. These findings suggest that a possible impact of TAF on weight gain should be taken into account when selecting ART components, especially in older patients or those with a long history of antiretroviral treatment.

Implementation of a Human Renal Proximal Tubule on a Chip for Nephrotoxicity and Drug Interaction Studies

Proximal tubule epithelial cells (PTEC) are susceptible to drug-induced kidney injury (DIKI). Cell-based, two-dimensional (2D) in vitro PTEC models are often poor predictors of DIKI, probably due to the lack of physiological architecture and flow. Here, we assessed a high throughput, 3D microfluidic platform (Nephroscreen) for the detection of DIKI in pharmaceutical development. This system was established with four model nephrotoxic drugs (cisplatin, tenofovir, tobramycin and cyclosporin A) and tested with eight pharmaceutical compounds. Measured parameters included cell viability, release of lactate dehydrogenase (LDH) and N-acetyl-β-d-glucosaminidase (NAG), barrier integrity, release of specific miRNAs, and gene expression of toxicity markers. Drug-transporter interactions for P-gp and MRP2/4 were also determined. The most predictive read outs for DIKI were a combination of cell viability, LDH and miRNA release. In conclusion, Nephroscreen detected DIKI in a robust manner, is compatible with automated pipetting, proved to be amenable to long-term experiments, and was easily transferred between laboratories. This proof-of-concept-study demonstrated the usability and reproducibility of Nephroscreen for the detection of DIKI and drug-transporter interactions. Nephroscreen it represents a valuable tool towards replacing animal testing and supporting the 3Rs (Reduce, Refine and Replace animal experimentation).

Comparison of viral control between two tenofovir dose reduction regimens (300 mg every 48 hours versus 300 mg every 72 hours) in chronic hepatitis B patients with moderate renal impairment from tenofovir-induced renal dysfunction

Long-term use of tenofovir disoproxil fumarate (TDF) can induce renal dysfunction that requires TDF dose reduction. Previous studies showed that systemic drug use exerts a threefold higher risk of moderate renal impairment. This study aimed to compare viral control between two tenofovir dose reduction regimens in chronic hepatitis B (CHB) patients with moderate renal impairment from TDF-induced renal dysfunction. This noninferiority, randomized controlled study was conducted at the Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand. Virologically suppressed CHB patients treated with TDF who had moderate renal impairment were randomly allocated to receive TDF 300 mg either every 48 or 72 hours. Forty-six patients (67.4% male) with a mean age of 62.8 ± 7.8 years were enrolled. Among all patients, 34.8% were HBeAg-positive, and 23.9% had cirrhosis. All included patients completed 12 months of follow-up. No patients had virological breakthrough. After dose reduction, estimated glomerular filtration rate (eGFR) was improved in both groups, but a higher proportion of patients had an eGFR > 60 mL/min/1.73 m² in the TDF every 72 hours group. Other renal parameters, including serum phosphate, tubular maximal reabsorption for phosphate per GFR, urine protein-to-creatinine ratio, urine sugar and urine neutrophil gelatinase-associated lipocalin, were not significantly different between groups. Among TDF-treated CHB patients with TDF-induced moderate renal impairment, more aggressive dose reduction in TDF from every 48 hours to every 72 hours did not affect virological breakthrough. A higher proportion of patients in the TDF every 72 hours group had improvement in renal function.

A Review on Drug-Induced Nephrotoxicity: Pathophysiological Mechanisms, Drug Classes, Clinical Management, and Recent Advances in Mathematical Modeling and Simulation Approaches

A variety of marketed drugs belonging to various therapeutic classes are known to cause nephrotoxicity. Nephrotoxicity can manifest itself in several forms depending on the specific site involved as well as the underlying pathophysiological mechanisms. As they often coexist with other pathophysiological conditions, the steps that can be taken to treat them are often limited. Thus, drug-induced nephrotoxicity remains a major clinical challenge. Prior knowledge of risk factors associated with special patient populations and specific classes of drugs, combined with early diagnosis, therapeutic drug monitoring with dose adjustments, as well as timely prospective treatments are essential to prevent and manage them better. Most incident drug-induced renal toxicity is reversible only if diagnosed at an early stage and treated promptly. Hence, diagnosis at an early stage is the need of the hour to counter it. Significant recent advances in the identification of novel early biomarkers of nephrotoxicity are not beyond limitations. In such a scenario, mathematical modeling and simulation (M&S) approaches may help to better understand and predict toxicities in a clinical setting. This review summarizes pathophysiological mechanisms of drug-induced nephrotoxicity, classes of nephrotoxic drugs, management, prevention, and diagnosis in clinics. Finally, it also highlights some of the recent advancements in mathematical M&S approaches that could be used to better understand and predict drug-induced nephrotoxicity.

Tenofovir disoproxil fumarate associated nephrotoxicity: a retrospective cohort study at two referral hospitals in Namibia

INTRODUCTION

The incidence and risk factors of tenofovir disoproxil fumarate (TDF)-related renal impairment (RI) in Namibia are unknown where TDF-containing ART regimens are used as the first line for HIV.

METHODOLOGY

A retrospective cohort study among HIV-infected patients at two intermediate hospitals. A decline in estimated glomerular filtration rate (eGFR) was significant if it was ≥25% and included a change to a lower eGFR stage. New-onset RI was defined as an eGFR <50 mL/min/1.73m² .

RESULTS

10 387 patients were included: 11.4% (n = 1182) experienced the decline in eGFR. Of these, 0.6% (n = 62) migrated to eGFR stages IV and V. The incidence was 4.5 (95% CI: 4.3-4.8) per 100 patient years. RI developed in 400 patients for an incidence rate of 2.4 (95% CI: 2.2-2.6) cases per 100 patient years. Risk factors with effect sizes >2.0, for decline-in-eGFR were baseline eGFR >60 (aHR = 15.6); hyperfiltration (aHR = 5.0); and pregnancy (aHR = 2.4); while for RI, they were hyperfiltration (aHR = 4.1) and pregnancy (aHR = 29).

CONCLUSION

The incidence of decline-in-eGFR was higher than in other sub-SSA countries, but not RI. A high baseline eGFR had the greatest risk for the decline, and hyperfiltration for the RI.

Recovery of Tenofovir-induced Nephrotoxicity following Switch from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in Human Immunodeficiency Virus-Positive Patients

Background

Tenofovir disoproxil fumarate (TDF)-induced nephrotoxicity is related to high plasma tenofovir concentrations. Tenofovir alafenamide (TAF) is a tenofovir prodrug with 90% lower plasma tenofovir concentrations. The aim of this study was to evaluate changes in tenofovir-induced nephrotoxicity in Human Immunodeficiency Virus (HIV)-positive patients who switched from TDF to TAF.

Materials and Methods

We identified all HIV-positive patients who switched from elvitegravir/cobicistat/emtricitabine/TDF to elvitegravir/cobicistat/emtricitabine/TAF at a tertiary hospital. We assessed tubulopathy and renal dysfunction before TDF administration, at the time TAF was used following at least 3 months of TDF use, and 3 months after TAF administration. Tubulopathy was defined by the presence of at least three abnormalities in fractional excretion of phosphate, fractional excretion of uric acid, urinary β2-microglobulin, urinary N-acetyl-β-D-glucosaminidase, glucosuria or proteinuria. Renal dysfunction was defined as decreased by more than 25% in the estimated glomerular filtration rate (eGFR) relative to baseline.

Results

In 80 patients, the mean eGFR was 96.8 mL/min/1.73 m² before administration of TDF, 81.2 (P <0.001) at the time of change to TAF, 90.9 (P <0.001) after TAF administration. Renal dysfunction occurred in 19 patients (23.8%) after TDF use for a median 15 months, 11 (57.9%) of these patients recovered from renal dysfunction after TAF administration. Six patients (7.5%) had tubulopathy before TDF administration, 36 (45.0%) after TDF administration (P <0.001), 12 (15.0%) after TAF administration (P = 0.002).

Conclusion

Tenofovir-induced nephrotoxicity in HIV-positive patients receiving TDF was mostly reversible after changing to TAF. Thus, TAF-containing regimens can be administered safely to HIV-positive patients with tenofovir-induced nephrotoxicity.

Benefits and Limits of Antiretroviral Drug Monitoring in Routine Practice

BACKGROUND

HIV infection is a chronic disease for which therapeutic adherence and tolerance require particular attention.

OBJECTIVE

This study aimed to assess whether and when therapeutic drug monitoring (TDM) could be associated with a benefit in routine practice.

METHODS

All HIV-infected patients who underwent at least one TDM at the University Hospital of Dijon (France) between 1st January 2009 and 31st December 2012 were retrospectively included. Compliance with the recommendations, the results (antiretroviral concentrations), any subsequent therapeutic modifications, and the virological results at 4-8 months were analysed each time TDM was performed. TDM was defined as "practically relevant" when low or high antiretroviral concentrations led to a change in therapy.

RESULTS

Of the 571 patients who followed-up, 43.4% underwent TDM. TDM complying with recommendations (120 patients) was associated with a higher proportion of antiretroviral concentrations outside the therapeutic range (p=0.03). Antiretroviral treatment was modified after TDM in 22.6% of patients. Protease inhibitors, non-nucleoside reverse transcriptase inhibitors and raltegravir were more significantly modified when the measured concentration was outside the therapeutic range (p=0.008, p=0.05 and p=0.02, respectively). Overall, 11.7% of TDM was considered "practically relevant", though there was no significant correlation between subsequent changes in antiretroviral treatment and undetectable final HIV viral load.

CONCLUSION

TDM may be a useful tool in the management of HIV infection in specific situations, but the overall benefit seems moderate in routine practice. TDM cannot be systematic and/or a decision tool per se, but should be included in a comprehensive approach in certain clinical situations.

Longitudinal Progression of Estimated GFR in HIV-1-Infected Patients with Normal Renal Function on Tenofovir-Based Therapy in China

Purpose

Estimated glomerular filtration rate (eGFR) decline in HIV-1-infected patients exposure to tenofovir disoproxil fumarate (TDF) has been widely assessed using linear models, but nonlinear assumption is not well validated. We constructed a retrospective cohort study to assess whether eGFR decline follows nonlinearity during antiviral therapy.

Patients and Methods

We examined 823 (299 of TDF users and 524 of non-TDF users) treatment-naïve HIV-1-infected participants (age ≥ 17 years, initial eGFR ≥ 90 mL/min/1.73m²). Estimated GFR trajectories were compared by one-linear and piecewise-linear mixed effects models, before and after propensity score matching, respectively. Whether the incidence of renal dysfunction (reduced renal function [RRF], eGFR < 90 mL/min/1.73 m² and rapid kidney function decline [RKFD], eGFR > -3 mL/min/1.73 m²/year) follows nonlinearity was assessed by logistic regression.

Results

The median follow-up time of this study was 10 (interquartile range, 2-20) months, during which 178 (21.6%) experienced RRF, and 451 (54.8%) experienced RKFD. The slopes (mL/min/1.73 m²/year) of eGFR were -5.31 (95% CI: -6.57, -4.06) before 1.40 years, 4.83 (95% CI: 1.38, 8.28) from years 1.40 to 2.30 and -3.71 (95% CI: -5.97, -1.45) after 2.30 years among TDF users. Within years 1.40-2.30, each year of TDF exposure was associated with a 78% decreased risk of RKFD (95% CI: -91%, -49%). In comparison, eGFR increased slightly at the initiation of antiviral therapy, declined after 2.15 years (-4.96; 95% CI: -5.76, -4.17) among non-TDF users. Such a progression nonlinear trajectory was missed on the assumption of one-linearity, whether in TDF or non-TDF users.

Conclusion

Over the piecewise mixed-effects analyses with the advantage of revealing the true nature of the exposure outcome relationships, an interesting reverse S-shaped relationship was observed. A routine screen based on nonlinearity could be more helpful for patient management.

Hepatitis B - Vertical transmission and the prevention of mother-to-child transmission

Hepatitis B virus (HBV) infection is the commonest cause of chronic hepatitis, with an estimated global prevalence of 3.5%, and which leads to significant morbidity and mortality. Mother-to-child transmission (MTCT) during pregnancy is the leading form of transmission in endemic populations, and its interruption is thus crucial as the initial step in the elimination of HBV infection, notwithstanding the availability of potent antiviral medications. The risk of MTCT is dramatically reduced by timely neonatal HBV vaccination and the administration of hepatitis B immunoglobulin after birth in high-risk infants. Maternal HBV DNA quantification during pregnancy allows the assessment of the risk of newborn immunoprophylaxis failure (IF). Maternal antiviral treatment in highly viremic women can reduce the risk of IF. However, the optimal HBV DNA cutoff level for the initiation of antiviral treatment remains to be determined.

Tenofovir disoproxil fumarate-induced distal renal tubular acidosis: A case report

Tenofovir disoproxil fumarate (TDF) is an anti-retroviral drug that is known to cause nephrotoxicity including renal tubular acidosis (RTA). With increasing literature on proximal RTA caused by TDF, reports on distal RTA are scarce, with only one case reported so far. We report a case of distal RTA in patient living with human immunodeficiency virus, who presented with nausea and fatigue giving a history of TDF-based therapy for two years. Laboratory investigations revealed non-anion gap metabolic acidosis, positive urine anion gap, hyperchloremia, and hypokalemia. The patient improved after discontinuing TDF and supportive management.

Effect of TDF-containing regimens on creatinine clearance in HIV patients in Namibia with a baseline CrCl <60ml/min; findings and implications

Background and aims: The advent of antiretroviral therapy (ART) and early diagnosis of the human immunodeficiency virus (HIV) has resulted in an appreciable reduction in morbidity and mortality among people infected with HIV. However, tenofovir disoproxil fumarate (TDF)-containing ART regimens are associated with a reduction in creatinine clearance (CrCl). No evaluation has been conducted in Namibia to date on the relationship between TDF-containing ART and CrCl among patients with moderate to severe reductions in CrCl to guide future practice. We aimed to address this.Methodology: Retrospective longitudinal study between January 2008 to December 2016 evaluating CrCl in patients with a baseline CrCl <60ml/min who were receiving TDF-containing ART in a leading hospital in Namibia. We identified patients who had experienced an improvement in CrCl and compared their characteristics with those whose CrCl did not improve. We assessed factors for an association with improvement in CrCl using binary logistic regression.Results: 389 patients were included, the majority were female (n = 294). Female vs. male assessments showed no difference in age (p = 0.340), weight (p = 0.920), number who experienced an improvement (105 vs 39, p = 0.349), or absence of improvement (189 vs. 56, p = 0.349). The improvement group (male and female) had a lower baseline CrCl (45.9 vs. 55.0, p < 0.001). The follow-up CrCl for the improvement and no improvement groups were 72.6 and 55.9 respectively. Multivariate analysis showed that the odds of improvement were: 0.905 (0.871-0.940, p < 0.001) for each unit rise in the baseline CrCl, and 0.904(0.880-0.923) for each year of follow-up.Conclusion: More improvement than decline in CrCl was observed. Improvement occurred more in patients with lower baseline CrCl, and occurred in the early period of ART with reduced odds of experiencing this with time. Our findings indicate that TDF may be used in patients with a low baseline CrCl.

Determinants of Risk Factors for Renal Impairment among HIV-Infected Patients Treated with Tenofovir Disoproxil Fumarate-Based Antiretroviral Regimen in Southern Vietnam

Background

The situation of renal impairment among HIV-infected patients treated with TDF-based antiretroviral (ARV) regimen greater than 3 years is little known when TDF use has been promptly increasing in Vietnam.

Methods

We analyse demographic and clinical data from a cross-sectional survey of 400 HIV-infected patients aged ≥18 years, who were treatment-naive or switched TDF regimen within over 3 years between November 2018 and March 2019. Serological tests for serum creatinine, ALT, and AST were performed. Renal impairment was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². Multivariate regression analyses were used to explore the risk factors associated with renal impairment.

Results

At the baseline, 7.8% of respondents had estimated glomerular filtration rate (eGFR) of 30-59 mL/min/1.73 m² and 0.8% had eGFR of 15-29 mL/min/1.73 m², out of 34 (8.5%) of participants who had renal impairment. Multivariate analysis showed that participants who had preexposure to isoniazid (adjusted PR [aPR] = 0.35 Cl: 0.14-0.91) compared with nonexposure to isoniazid who had a BMI from 18.5 up to 25 kg/m² (aPR = 0.31 Cl: 0.15-0.62) compared with BMI below 18.5 kg/m² were less likely to suffer from renal impairment. Patients aged greater than 60 years (aPR = 26.75, 95% Cl: 3.38-211.62) compared with those aged 20-29 years were more likely to have increased risk of renal impairment.

Conclusion

Our findings underscore the need for longitudinal studies to assess the influence of TDF on maintaining the low prevalence of renal impairment among HIV-infected patients in Vietnam.

Melatonin ameliorates the drug induced nephrotoxicity: Molecular insights

BACKGROUND

Drug-induced nephrotoxicity is a frequent adverse event that can lead to acute or chronic kidney disease and increase the healthcare expenditure. It has high morbidity and mortality incidence in 40-70% of renal injuries and accounts for 66% cases of renal failure in elderly population.

OBJECTIVE

Amelioration of drug-induced nephrotoxicity has been long soughed to improve the effectiveness of therapeutic drugs. This study was conducted to review the melatonin potential to prevent the pathogenesis of nephrotoxicity induced by important nephrotoxic drugs.

METHODS

We analyzed the relevant studies indexed in Pubmed, Medline, Scielo and Web of science to explain the molecular improvements following melatonin co-administration with special attention to oxidative stress, inflammation and apoptosis as key players of drug-induced nephrotoxicity.

RESULTS

A robust consensus among researchers of these studies suggested that melatonin efficiently eradicate the chain reaction of free radical production and induced the endogenous antioxidant enzymes which attenuate the lipid peroxidation of cellular membranes and subcellular oxidative stress in drug-induced nephrotoxicity. This agreement was further supported by the melatonin role in disintegration of inflammatory process through inhibition of principle pro-inflammatory or apoptotic cytokines such as TNF-α and NF-κB. These studies highlighted that alleviation of drug-induced renal toxicity is a function of melatonin potential to down regulate the cellular inflammatory and oxidative injury process and to stimulate the cellular repair or defensive mechanisms.

CONCLUSION

The comprehensive nephroprotection and safer profile suggests the melatonin to be a useful adjunct to improve the safety of nephrotoxic drugs.

Kidney-based in vitro models for drug-induced toxicity testing

The kidney is frequently involved in adverse effects caused by exposure to foreign compounds, including drugs. An early prediction of those effects is crucial for allowing novel, safe drugs entering the market. Yet, in current pharmacotherapy, drug-induced nephrotoxicity accounts for up to 25% of the reported serious adverse effects, of which one-third is attributed to antimicrobials use. Adverse drug effects can be due to direct toxicity, for instance as a result of kidney-specific determinants, or indirectly by, e.g., vascular effects or crystals deposition. Currently used in vitro assays do not adequately predict in vivo observed effects, predominantly due to an inadequate preservation of the organs' microenvironment in the models applied. The kidney is highly complex, composed of a filter unit and a tubular segment, together containing over 20 different cell types. The tubular epithelium is highly polarized, and the maintenance of this polarity is critical for optimal functioning and response to environmental signals. Cell polarity is dependent on communication between cells, which includes paracrine and autocrine signals, as well as biomechanic and chemotactic processes. These processes all influence kidney cell proliferation, migration, and differentiation. For drug disposition studies, this microenvironment is essential for prediction of toxic responses. This review provides an overview of drug-induced injuries to the kidney, details on relevant and translational biomarkers, and advances in 3D cultures of human renal cells, including organoids and kidney-on-a-chip platforms.

Dual therapy with lopinavir/ritonavir plus lamivudine could be a viable alternative for antiretroviral-therapy-naive adults with HIV-1 infection regardless of HIV viral load or subgenotype in resource-limited settings: A randomised, open-label and non-inferiority study from China

Backgrounds

This randomised controlled, open-label, non-inferiority trial was conducted in antiretroviral-naïve HIV-1-infected patients to assess the efficacy and safety of 48-week dual therapy of LPV/r plus 3TC (DT group) compared with Chinese first-line triple-therapy regimen (TT group).

Methods

198 were randomised to DT (n = 100) or TT (n = 98).

Results

Ninety-two DT patients (92%) and 88 TT patients (89.8%) achieved HIV-1 RNA <50 copies/ml at week 48 (P = 0.629). Moreover, the safety profile was similar between two groups, and no secondary HIV resistance was observed.

Conclusion

The results suggest that dual therapy of LPV/r plus 3TC is non-inferior to the first-line triple-therapy regimen in China.

Effects of long-term exposure to tenofovir disoproxil fumarate-containing antiretroviral therapy on renal function in HIV-positive Chinese patients

BACKGROUND

The regimen containing tenofovir disoproxil fumarate (TDF)+lamivudine or emtricitabine + efavirenz remains the recommended first-line antiretroviral therapy (ART) by the WHO. Limited studies, however, have been conducted on the incidence of renal impairment among Chinese patients with long-term exposure to TDF-containing ART regimens.

METHODS

We retrospectively analyzed 269 eligible patients who had no comorbidities and received TDF-containing ART from July 2014 to April 2015. TDF-related renal impairment was defined as a decrease of eGFR by >25% from baseline or eGFR <90 ml/min/1.73 m². Decreased renal function was defined as a decrease of eGFR by > 10 mL/min/1.73 m² from baseline.

RESULTS

97.0% of study patients were male (median age 29, eGFR 124.0 ml/min/1.73 m²). After 168-week of ART, renal impairment occurred in 7 patients (2.7%). The incidence of decreased renal function was significantly higher at Week 168 compared with that observed at Week 12 (24.8% vs 3.7%, p < 0.001). In generalized estimating equation analysis, patients receiving ART for 144-week (aOR4.1, 95%CI 2.0-8.4) and 168-week (aOR8.4, 95%CI 4.2-16.4) were more likely to develop decreased renal function compared with those receiving ART for 12-week, so were the patients with a weight <58 kg (aOR2.3, 95%CI 1.2-4.3) and 58-66 kg (aOR2.0, 95%CI 1.0-3.8) compared to those with a weight ≥67 kg. At 168-week, 41.0% of 100 patients examined had elevated urine β2-microglobulin levels, which were negatively correlated with eGFR (r = -0.22, p = 0.02).

CONCLUSIONS

TDF-related renal impairment remained rare in HIV-positive Chinese patients with a median age of 29 years who had no comorbidities. A lower weight and duration of ART were associated with decreased renal function.

Living kidney donation in individuals with hepatitis C and HIV infection: rationale and emerging evidence

PURPOSE OF REVIEW

HIV-infected (HIV+) and hepatitis C virus-infected (HCV+) individuals with end-stage renal disease (ESRD) have decreased access to kidney transplantation. With new opportunities provided by the HIV Organ Policy Equity (HOPE) Act and direct-acting antivirals (DAAs) for HCV, we explore the potential risks and benefits of living donor kidney transplantation from HIV+ or HCV+ donors, from the perspective of both donor health and recipient outcomes.

RECENT FINDINGS

The HOPE Act permits organ donation from both deceased and living HIV+ persons to HIV+ recipients; however, there is only clinical experience with HIV+ deceased donors to date. Empirical evidence demonstrates a low but acceptable risk of ESRD in potential HIV+ living donors without comorbidities who have well-controlled infection in the absence of donation. With the availability of potent DAAs for eradication of HCV infection, growing evidence shows good outcomes with HCV seropositive and/or viremic deceased kidney donors, providing rationale to consider HCV+ living donors.

SUMMARY

HIV+ and HCV+ living donor kidney transplantation may improve access to transplant for vulnerable ESRD populations. Careful evaluation and monitoring are warranted to mitigate potential risks to donors and recipients.

A case of entecavir-induced Fanconi syndrome

Acquired Fanconi syndrome has been associated with the long-term ingestion of several nucleoside analogs used to treat chronic hepatitis B virus infection. However, the nucleoside analog entecavir has not been found to cause nephrotoxicity. We report a case of entecavir-induced Fanconi syndrome. Our patient was a 73-year-old man admitted to our hospital because of renal dysfunction. He also presented with hyperaminoaciduria, renal diabetes, phosphaturia, hypophosphatemia, hypokalemia, hypouricemia, and hyperchloremic metabolic acidosis, supporting a diagnosis of Fanconi syndrome. In this case, the cause of Fanconi syndrome was most likely entecavir, which had been administered as needed depending on his renal function for 5 years. After drug discontinuation and replacement with tenofovir alafenamide fumarate therapy once a week, the patient's kidney function recovered and electrolyte anomalies partially improved. We highlight the fact that entecavir may induce severe renal dysfunction, which can cause the development of Fanconi syndrome; therefore, close monitoring of proximal tubular function is recommended during entecavir therapy.

Has vitamin E any shreds of evidence in cisplatin-induced toxicity

Cisplatin is one of the highly consumed and effective antitumor agents whose clinical application is accompanied by nephrotoxicity adverse reaction. Also, other complications such as ototoxicity and hepatotoxicity are a matter of concern. Today, it is suggested that cisplatin-associated toxicities are mainly induced by free radicals production, which will result in oxidative organ injury. The evidence is growing over the protective effects of antioxidants on cisplatin-induced adverse reactions especially nephrotoxicity. The possible protective effects of vitamin E and its derivative in cisplatin-induced nephrotoxicity and ototoxicity are reviewed here at the light of pertinent results from basic and clinical research. Administration of vitamin E alone or in combination with other antioxidant agents could cause amelioration in oxidative stress biomarkers such as decreasing the level of malondialdehyde, reducing serum urea and creatinine, and also enhancing the activities of renal antioxidant enzymes including renal catalase, glutathione-S-transferase, and superoxide dismutase. Although the data from most of the studies are in favors of protective effects of vitamin E against cisplatin-induced toxicity, more clinical trials are needed to clarify the clinical importance of vitamin E administration as an antioxidant during cisplatin therapy in cancer condition.

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Lipid profile and renal safety of tenofovir disoproxil fumarate-based anti-retroviral therapy in HIV-infected Chinese patients

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is an important component of antiretroviral therapy (ART) that has been widely used. The aim of this study was to observe the long-term impact of TDF-based ART on lipid metabolism profiles and renal functions in Chinese patients.

METHODS

414 and 124 HIV-infected, ART-naïve patients who initiated TDF-based regimens and non-TDF regimens respectively were retrospectively included. Demographic characteristics and clinical information of each patient was collected. Changes of lipid profiles and renal function, as well as the risk factors of hyperlipidemia and renal dysfunction were analyzed.

RESULTS

After 96 weeks of ART, HIV viral loads were undetectable in 97.34% (403/414) of patients exposed to TDF. The plasma total cholesterol (TCH) increased from 3.97 ± 0.83 mmol/L to 4.53 ± 0.87 mmol/L (P < 0.001), which did not show a significant difference comparing with non-TDF exposed group. By contrast, the plasma triglyceride (TG) levels increased, but were still lower than that in the non-TDF exposed group (0.26 ± 1.24 vs. 0.89 ± 1.78, P < 0.001). The mean estimated glomerular filtration rate (eGFR) decreased from 127.29 ± 24.04ml∙min^-1∙1.73 m^-2 at baseline to 118.84 ± 22.74 ml∙min^-1∙1.73 m^-2(P < 0.001) in the TDF exposed group, while it increased in the non-TDF exposed group. In the TDF group, high body mass index (BMI) (OR = 1.13, P = 0.01), high baseline TG (OR = 2.33, P<0.001) and receiving protease inhibitors (PIs) (OR = 7.58, P < 0.001) were associated with hypertriglyceridemia after ART, while high baseline TCH predicted hypercholesterolemia (OR = 3.58, P < 0.001). MSM (OR = 0.22, P = 0.02) and baseline eGFR (OR = 0.90, P < 0.001) was associated with renal dysfunction after ART.

CONCLUSIONS

TDF-based regimens are of good therapeutic effect among Chinese people. These regimens showed a better plasma lipid profile but mild renal dysfunction as compared to non-TDF based regimens. Patients with high BMI, high baseline TG, high baseline TCH and low baseline eGFR should be closely monitored when using TDF-based ART.

Reduced Kidney Function in Tenofovir Disoproxil Fumarate Based Regimen and Associated Factors: A Hospital Based Prospective Observational Study in Ethiopian Patients

Purpose

Tenofovir disoproxil fumarate (TDF), a drug broadly used in combination antiretroviral therapy, is associated with renal dysfunction but the prevalence varied from country to country and it is not known in Ethiopia. The objectives of this study were to assess the prevalence of renal dysfunction and risk factors associated with it and the mean change in estimated glomerular filtration rate in human immunodeficiency virus infected patients receiving TDF based antiretroviral regimen at Tikur Anbessa Specialized Hospital.

Method

It was a hospital based prospective cohort study. The study participants were treatment naïve HIV infected patients initiating TDF containing combination antiretroviral therapy or switched to it because of adverse events. Multivariable logistic analysis was used to identify variables which have significant association.

Result

A total of 63 study participants were studied, 16 (25.4%) of whom had fall in eGFR greater than 25% relative to baseline. Only age greater than 50 years, baseline CD4 count less than 200 cells/mm³, and baseline proteinuria were significantly associated with renal dysfunction in multivariable logistic regression. There was -8.4 ml/min/1.73m² mean change in estimated glomerular filtration rate relative to baseline at six months of study.

Conclusion

The renal dysfunction (defined as decline in eGFR greater than 25%) was found in a quarter of the study population. The long term impact and the clinical implication of it are not clear. Future prospective study is required with large sample size and long duration to ascertain the prevalence of decline greater than 25% in estimated glomerular filtration rate and its progression to chronic kidney disease.

Risk of renal events during tenofovir disoproxil fumarate and entecavir antiviral prophylaxis in HBsAg-positive cancer patients undergoing chemotherapy

The risk of renal events in HBsAg-positive cancer patients receiving tenofovir disoproxil fumarate (TDF) or entecavir (ETV) antiviral prophylaxis during chemotherapy has not been evaluated. This study aimed to evaluate the renal safety of TDF and ETV during chemotherapy. Consecutive, 219 HBsAg-positive cancer patients treated with TDF (n = 106) or ETV (n = 113) for antiviral prophylaxis during chemotherapy with baseline serum creatinine (SCr) <1.2 mg/dL were retrospectively enrolled. Serial SCr levels and estimated glomerular filtration rate (eGFR) were monitored. The incidence of acute kidney injury (AKI) during antiviral prophylaxis was 33% and 38.9% in TDF and ETV groups, respectively (P = 0.441), while the incidence of sustained kidney injury was 11.3% and 11.5%, respectively (P = 1.000). By multivariate analysis, diuretics use (hazard ratio (HR) = 2.011, P = 0.042) and serum albumin levels (HR = 0.441, P = 0.001) were independent predictors of AKI; serum albumin levels (HR = 0.252, P = 0.002) was the only factor associated with sustained kidney injury; age (HR = 2.752, P < 0.001), baseline SCr levels (HR = 3.386, P < 0.001), and serum albumin levels (HR = 0.437, P = 0.001) were factors associated with a new eGFR <60 mL/min. 34.9% of patients in TDF group and 35.4% in ETV group had deteriorated chronic kidney disease (CKD) stage at the end of follow-up, respectively. There were no significant differences in the risk of renal events or CKD stage migration between TDF and ETV groups. Renal events may develop in about one-third of HBsAg-positive cancer patients undergoing chemotherapy. The risk of renal function impairment was comparable between patients treated with TDF and ETV antiviral prophylaxis.