Nephrotoxicity caused by oral antiviral agents in patients with chronic hepatitis B treated in a hospital for tropical diseases in Thailand

Changes in Renal Function in Patients With Chronic HBV Infection Treated With Tenofovir Disoproxil Fumarate vs Entecavir

BACKGROUND & AIMS

It is unclear whether drugs used to treat chronic hepatitis B virus (HBV) infection cause significant renal impairment. We compare adjusted mean estimated glomerular filtration rates (eGFR; mL/min/1.73 m²) of patients with chronic HBV infection treated with tenofovir disoproxil fumarate (TDF) vs patients treated with entecavir.

METHODS

We performed a retrospective study of patients with chronic HBV infections treated with TDF (n = 239) or entecavir (n = 171), from 2000 through 2016, followed for a mean time of 43-46 months. Levels of serum creatinine were measured ≥12 months while patients received treatment. Patients did not have prior exposure to adefovir or HCV, HDV, or HIV co-infection. We performed propensity score matching (PSM) for age, sex, presence of hypertension, diabetes mellitus, baseline eGFR, cirrhosis, and follow-up duration. We performed multivariate generalized linear modeling, adjusting for cirrhosis, diabetes, and hypertension, to estimate adjusted mean eGFR for matched and unmatched cohorts. Cox regression was used to identify predictors of renal impairment.

RESULTS

eGFRs were ≥60, after PSM, in 116 patients given entecavir and in 116 patients given TDF; eGFRs were <60 in 32 patients given entecavir and 26 patients given TDF. Multivariate generalized linear modeling of the unmatched overall and <60 eGFR cohorts revealed significantly lower adjusted mean eGFRs in patients given TDF (all P < .001). However, in the eGFR ≥60 PSM cohort, the adjusted mean eGFR was similar between patients receiving either treatment. In Cox regression analysis, TDF was not associated with mild or moderate renal impairment compared with entecavir.

CONCLUSION

In a retrospective study of patients with chronic HBV infections treated with TDF vs entecavir, we found that TDF was not associated with higher risk of worsening renal function during short- or intermediate-term follow-up periods, among patients without significant renal impairment. Additional studies, with longer follow-up periods, are needed because treatment for chronic HBV infection is generally long term or life-long. For patients with baseline renal impairment, significant renal decline was among patients given TDF compared to patients given entecavir.

[Hepatitis B and renal failure: prevalence and associated factors in National University Hospital Center of Cotonou]

Introduction

the association between the kidneys and hepatitis B is complex. This study aims to determine the prevalence and factors associated with renal disease in people living with hepatitis B virus (PLHBV) in Cotonou.

Methods

we conducted a cross-sectional, descriptive and analytical study in the Hepatogastroenterology Department at the National University Hospital Center in Cotonou over the period May -August 2017. All the patients with positive hepatitis B surface antigen (HBS Ag) test hospitalized in the study period were included. The diagnosis of renal failure was retained in patients with glomerular filtration rate less than 90 mL/min/1.73 m² (estimated with MDRD Equation).

Results

the study involved 105 patients with positive hepatitis B surface antigen (HBS Ag) test Among them, 65 (61.9%) were under anti-HBV treatment ( 62 of them were under tenofovir ); 41 patients had renal failure (39%) with tubular involvement (2 cases) and glomerular involvement (4 cases). Renal function had got progressively worse over time in 22 patients (21%) and had improved in 6 patients (5.7%). Univariate analysis showed that factors associated with the occurrence of renal failure were: age greater than 50 years (p = 0.0125), high blood pressure (p = 0.0037), initially abnormal renal function (p < 0.0003) and co-medications (p = 0.0007). Anti-HBV treatment wasn't associated with the occurrence of renal failure (p = 0.2887).

Conclusion

the prevalence of renal failure in PLHBV was high (39%). Age, arterial hypertension, pre-existing renal failure and co-medications were identified as factors associated with decline in renal function in PLHBV.

Drug-Induced Kidney Stones and Crystalline Nephropathy: Pathophysiology, Prevention and Treatment

Drug-induced calculi represent 1-2% of all renal calculi. The drugs reported to produce calculi may be divided into two groups. The first one includes poorly soluble drugs with high urine excretion that favour crystallisation in the urine. Among them, drugs used for the treatment of patients with human immunodeficiency, namely atazanavir and other protease inhibitors, and sulphadiazine used for the treatment of cerebral toxoplasmosis, are the most frequent causes. Besides these drugs, about 20 other molecules may induce nephrolithiasis, such as ceftriaxone or ephedrine-containing preparations in subjects receiving high doses or long-term treatment. Calculi analysis by physical methods including infrared spectroscopy or X-ray diffraction is needed to demonstrate the presence of the drug or its metabolites within the calculi. Some drugs may also provoke heavy intra-tubular crystal precipitation causing acute renal failure. Here, the identification of crystalluria or crystals within the kidney tissue in the case of renal biopsy is of major diagnostic value. The second group includes drugs that provoke the formation of urinary calculi as a consequence of their metabolic effects on urinary pH and/or the excretion of calcium, phosphate, oxalate, citrate, uric acid or other purines. Among such metabolically induced calculi are those formed in patients taking uncontrolled calcium/vitamin D supplements, or being treated with carbonic anhydrase inhibitors such as acetazolamide or topiramate. Here, diagnosis relies on a careful clinical inquiry to differentiate between common calculi and metabolically induced calculi, of which the incidence is probably underestimated. Specific patient-dependent risk factors also exist in relation to urine pH, volume of diuresis and other factors, thus providing a basis for preventive or curative measures against stone formation.