Predictors of kidney tubular dysfunction induced by adefovir treatment for chronic hepatitis B.

AIM: To investigate the predictors of proximal kidney tubular dysfunction (PKTD) induced by adefovir dipivoxil (ADV) treatment for chronic hepatitis B. METHODS: Seventy-nine patients (age at the evaluation of PKTD: 56.9±10.7 years) with chronic hepatitis B undergoing long-term oral antiviral nucleos(t)ide analogue treatment were consecutively recruited. PKTD was defined by the presence of at least two of the following five abnormalities: phosphate diabetes, nondiabetic glucosuria, metabolic acidosis, ß2-microglobulinuria, or renal hypouricemia. The single-nucleotide polymorphisms (SNPs) in the SLC22A6 gene encoding human organic anion transporter 1 (hOAT1) and ABCC2 encoding multidrug resistance protein 2 (MRP2) were analyzed using the TaqMan Allelic Discrimination Demonstration Kit. RESULTS: Nine (30.0%) of the 30 ADV-treated patients were diagnosed with PKTD, while no patients without ADV developed PKTD (P<0.001). Three patients with ADV were diagnosed with symptomatic osteomalacia. Among the patients who took ADV, those with PKTD were of higher age at initiation, had significantly longer treatment duration, and had a significantly lower body mass index than those without PKTD. The incidence of PKTD dramatically increased after 96 mo from the start of ADV administration. In contrast, the SNPs were not correlated with PKTD. Logistic regression analysis extracted older age at initiation (OR=5.0, 95%CI: 1.1-23.4; P=0.040) and longer treatment duration (OR=3.2, 95%CI: 1.2-8.6; P=0.020) as significant factors associated with PKTD. CONCLUSION: Our results suggest that the tubular function of the kidney of older patients undergoing long-term ADV treatment should be carefully evaluated.

An investigation of the pattern of kidney injury in HIV-positive persons exposed to tenofovir disoproxil fumarate: an examination of a large population database (MHRA database).

The potential for tenofovir to cause a range of kidney syndromes has been established from mechanistic and randomised clinical trials. However, the exact pattern of kidney involvement is still uncertain. We undertook a descriptive analysis of Yellow Card records of 407 HIV-positive persons taking tenofovir disoproxil fumarate (TDF) as part of their antiretroviral therapy regimen and submitted to the Medicines and Healthcare Products Regulatory Agency (MHRA) with suspected kidney adverse effects. Reports that satisfy defined criteria were classified as acute kidney injury, kidney tubular dysfunction and Fanconi syndrome. Of the 407 Yellow Card records analysed, 106 satisfied criteria for TDF-related kidney disease, of which 53 (50%) had features of kidney tubular dysfunction, 35 (33%) were found to have features of glomerular dysfunction and 18 (17%) had Fanconi syndrome. The median TDF exposure was 316 days (interquartile range 120-740). The incidence of hospitalisation for TDF kidney adverse effects was high, particularly amongst patients with features of Fanconi syndrome. The pattern of kidney syndromes in this population series mirrors that reported in randomised clinical trials. Cessation of TDF was associated with complete restoration of kidney function in up half of the patients in this report.