Atazanavir nephrotoxicity

Drug-Induced Urinary Stone of Atazanavir Incidentally Found in an Asymptomatic Patient: A Case Report

A HIV-infected female treated with a combination of emtricitabine/elvitegravir/tenofovir since 2017 presented an acute renal failure during her hospitalization for a SARS-CoV2 pneumonia. A computed tomography demonstrated left ureterohydronephrosis and ureteral stone. Fragments extracted by ureteroscopy showed a calculus composed of atazanavir and calcium oxalate. The patient’s medical history showed atazanavir intake during ten years and then discontinued in 2017. This case report emphasizes that drug-induced urolithiasis should be considered when renal function declines, even far from discontinuation of atazanavir and without clinical signs of renal colitis. Moreover, identification of risk factors should alert to the possibility of drug-induced nephrolithiasis.

Drug-Induced Acute Kidney Injury

Medications are a common cause of AKI especially for patients admitted to hospital wards and the intensive care unit. Although drug-related kidney injury occurs through different mechanisms, this review will focus on three specific types of tubulointerstitial injury. Direct acute tubular injury develops from several medications, which are toxic to various cellular functions. Their excretory pathways through the proximal tubules contribute further to AKI. Drug-induced AKI may also develop through induction of inflammation within the tubulointerstitium. Medications can elicit a T cell-mediated immune response that promotes the development of acute interstitial nephritis leading to AKI. Although less common, a third pathway to kidney injury results from the insolubility of drugs in the urine leading to their precipitation as crystals within distal tubular lumens, causing a crystalline-related AKI. Intratubular obstruction, direct tubular injury, and localized inflammation lead to AKI. Clinicians should be familiar with the pathogenesis and clinical-pathologic manifestations of these forms of kidney injury. Prevention and treatment of AKI relies on understanding the pathogenesis and judiciously using these agents in settings where AKI risk is high.

The Crystalline Nephropathies

Crystalline nephropathies are a unique form of kidney disease characterized by the histologic finding of intrarenal crystal deposition. The intrinsic nature of some molecules and ions combined with a favorable tubular fluid physiology leads to crystal precipitation and deposition within the tubular lumens. Crystal deposition promotes kidney injury through tubular obstruction and both direct and indirect cytotoxicities. Further kidney injury develops from inflammation triggered by these crystals. From a clinical standpoint, the crystalline nephropathies are associated with abnormal urinalysis and urinary sediment findings, tubulopathies, acute kidney injury (AKI), and/or chronic kidney disease (CKD). Urine sediment examination is often helpful in alerting clinicians to the possibility of crystal-related kidney injury. The identification of crystals within the kidneys on biopsy by pathologists prompts clinicians to evaluate patients for medication-related kidney injury, dysproteinemia-related malignancies, and certain inherited disorders. This review will focus on the clinical and pathologic aspects of these 3 categories of crystalline nephropathies.

Pharmacotherapeutic options for kidney disease in HIV positive patients

INTRODUCTION

Since the developmentof combined antiretroviral therapy (cART), HIV-associated mortality and the incidence of HIV-associated end-stage kidney disease (ESKD) has decreased. However, in the United States, an increase in non-HIV-associated kidney diseases within the HIV-positive population is expected.

AREAS COVERED

In this review, the authors highlight the risk factors for kidney disease within an HIV-positive population and provide the current recommendations for risk stratification and for the monitoring of its progression to chronic kidney disease (CKD), as well as, treatment. The article is based on literature searches using PubMed, Medline and SCOPUS.

EXPERT OPINION

The authors recommend clinicians (1) be aware of early cART initiation to prevent and treat HIV-associated kidney diseases, (2) be aware of cART side effects and discriminate those that may become more nephrotoxic than others and require dose-adjustment in the setting of eGFR ≤ 30ml/min/1.73m², (3) follow KDIGO guidelines regarding screening and monitoring for CKD with a multidisciplinary team of health professionals, (4) manage other co-infections and comorbidities, (5) consider changing cART if drug induced toxicity is established with apparent eGFR decline of ≥ 10ml/min/1.73m² or rising creatinine (≥0.5mg/dl) during drug-drug interactions, and (6) strongly consider kidney transplant in appropriately selected individuals with end stage kidney failure.

A diagnostician's field guide to crystalline nephropathies

The kidney's role in filtration of blood and production of urine occurs via a combination of size and charge filtration at the glomerular basement membrane and resorption and excretion of molecules through a complex tubular system embedded within an ion gradient. This delicate system provides the kidney with a unique propensity for substrate saturation and crystal nucleation within the nephron. While crystalline nephropathies may seem exotic to the uninitiated, they are comprised of easily recognizable morphologies and generally lack complicated classification schemas. Additionally, unlike many intrinsic kidney diseases, crystalline nephropathies are often associated with systemic conditions that, upon further investigation, may elucidate critically important information. This review focuses on practical, diagnostically relevant and high yield information that can be utilized by diagnosticians. Our hope is to equip the reader who reviews renal tissue with a practical toolkit that they feel empowered to use when faced with crystal formation in a kidney biopsy, pre-implantation biopsy, or nephrectomy specimen. Short Abstract The kidney's role in filtration of blood and production of urine provides a unique propensity for substrate saturation and crystal nucleation within the nephron. While crystalline nephropathies may seem exotic to the uninitiated, they are comprised of easily recognizable morphologies and generally lack complicated classification. Additionally, crystalline nephropathies are often associated with systemic conditions that, upon further investigation, may elucidate critically important information.

A pharmaceutical industry perspective on microphysiological kidney systems for evaluation of safety for new therapies

The human kidney contains approximately one million nephrons. As the functional unit of the kidney, the nephron affords an opportunity to approximate the kidney at a microphysiological scale. Recent emergence of physiologically accurate human tissue models has radically advanced the possibilities of mimicking organ biology and multi-organ combinations in vitro. Anatomically, the nephron is one of the most complex, sequentially integrated microfluidic units in the body making the miniaturized microfluidic systems excellent candidates for capturing the kidney biology in vitro. While these models are promising, there are a number of considerations for practical implementation into a drug development paradigm. Opportunities for pharmaceutical industry applications of new MPS models often start with drug safety testing. As such, the intent of this article is to focus on safety and ADME applications. This article reviews biological functions of the kidney and options for characterizing known roles in nephrotoxicity. The concept of "context-of-use" is introduced as a framework for describing and verifying the specific features of an MPS platform for use in drug development. Overall, we present a perspective on key attributes of microphysiological kidney models, which the pharmaceutical industry could leverage to improve confident safety and ADME evaluations of experimental therapies.

A high likelihood of increase in end-stage renal disease among the Japanese HIV-infected population

Kidneys are affected by human immunodeficiency virus (HIV) infection and its associated therapies. Antiretroviral therapy (ART) has markedly reduced acquired immune deficiency syndrome–related deaths and opportunistic infectious diseases among HIV-infected patients. This contributed to their prolonged survival; however, the improvement in survival has been accompanied by an increase in the incidence of non-infectious chronic complications, including hypertension, metabolic diseases, and chronic kidney disease (CKD). Recent studies showed that estimated prevalence of any CKD and end-stage renal disease (ESRD) among HIV-infected patients is approximately 20% and 0.5%, respectively, in Japan. Both a rapid decrease in renal function and a high positive rate of albuminuria and proteinuria are clinical characteristics of HIV-infected patients. Moreover, considering higher complication rates of hypertension and diabetes compared with non-HIV-infected individuals of the similar aging, HIV-infected patients who develop CKD and ESRD are very likely to increase. Furthermore, as the survival rate is favorable after the initiation of dialysis, the cumulative number of ESRD patients is supposed to increase. The corporation for treatment of HIV-positive hemodialysis patients by general dialysis clinics will be urgently required; however, there still remain some preoccupations and prejudices about HIVper sein Japan, which may provoke hesitation from accepting those patients.

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.

Switching Antiretroviral Therapy in the Setting of Virologic Suppression: A Why and How-To Guide

This review provides a synopsis of key clinical considerations for switching antiretroviral therapy (ART) for individuals with human immunodeficiency virus who have maintained a routinely suppressed viral load. There may be benefits but also risks involved in every ART regimen change, so strategies for prioritizing individuals for a switch based on the specific antiretroviral agents in the regimen are discussed, along with approaches to ensure maintenance of viral suppression after treatment modifications. Controversial and evolving questions in the area of ART switches and simplifications are also considered.

The Changing Face of Human Immunodeficiency Virus-Mediated Kidney Disease

In nearly 40 years since human immunodeficiency virus (HIV) first emerged, much has changed. Our understanding of the pathogenesis of HIV infection and its effect on the cells within each kidney compartment has progressed, and the natural history of the disease has been transformed. What was once an acutely fatal illness is now a chronic disease managed with oral medications. This change is largely due to the advent of antiretroviral drugs, which have dramatically altered the prognosis and progression of HIV infection. However, the success of antiretroviral therapy has brought with it new challenges for the nephrologist caring for patients with HIV/acquired immune deficiency syndrome, including antiretroviral therapy-induced nephrotoxicity, development of non-HIV chronic kidney disease, and rising incidence of immune-mediated kidney injury. In this review, we discuss the pathogenesis of HIV infection and how it causes pathologic changes in the kidney, review the nephrotoxic effects of select antiretroviral medications, and touch upon other causes of kidney injury in HIV cases, including mechanisms of acute kidney injury, HIV-related immune complex glomerular disease, and thrombotic microangiopathy.

Clinical Pharmacology in HIV Therapy

The success of combination antiretroviral therapy in the treatment of HIV-1-positive individuals has shifted clinical attention toward combination antiretroviral drug regimens that optimize tolerability, long-term safety, and durable efficacy. Wherever patients have access to treatment, morbidity and mortality are increasingly driven by non-HIV-associated comorbidities, which may be observed earlier than in age-matched controls and despite the best available combination antiretroviral therapy. Similarly, HIV-1-positive individuals are now diagnosed and treated earlier with anticipated lifelong therapy. The contribution of specific antiretroviral agents to long-term morbidity and mortality is dependent on the pharmacologic characteristics of these agents, and it is increasingly important in this context.

Changing concepts of HIV infection and renal disease

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) was identified as the major renal manifestation of HIV infection early in the HIV epidemic. However, HIV infection now is associated with a different spectrum of renal lesions leading to chronic kidney disease. This review examines the changes in kidney injury occurring in the current HIV era and the factors involved in this transformation of disease expression.

RECENT FINDINGS

The incidence of HIVAN and opportunistic infections in HIV-infected individuals has declined in concert with the use of effective combination antiretroviral agents. Chronic kidney disease has become more prevalent as patients infected with HIV are living longer and developing non-HIV-associated diseases such as hypertension and diabetes. Additionally, noncollapsing focal and segmental glomerulosclerosis, co-infection with hepatitis C, HIV-associated immune complex kidney disease, HIV-related accelerated aging, and antiretroviral therapies contribute to progressive loss of renal function.

SUMMARY

HIV infection is now associated with a variety of renal lesions causing chronic kidney disease, not all of which are virally induced. It is important to determine the cause of renal functional decline in an HIV-infected patient, as this will impact patient management and prognosis.

Case of human immunodeficiency virus infection presenting as a tip variant of focal segmental glomerulosclerosis: A case report and review of the literature

The incidence of the collapsing variant of focal segmental glomerulosclerosis (FSGS) as a human immunodeficiency virus (HIV)-associated nephropathy has reduced since the introduction of antiretroviral therapy (ART). However, the incidence of other variants of FSGS, except for the collapsing variant, is increasing, and its therapeutic strategies remain uncertain. A 60-year-old HIV infected man in remission with ART was admitted for progressive renal insufficiency and nephrotic-ranged proteinuria. Renal biopsy revealed a tip variant of FSGS and his clinical manifestations resolved with corticosteroid therapy. HIV infected patients might develop non-collapsing FSGS, including tip variant of FSGS and corticosteroid therapy might be effective for them. A renal biopsy might be essential to determine the renal histology and to decide on corticosteroid therapy.

Long-term kidney function, proteinuria, and associated risks among HIV-infected and uninfected men

BACKGROUND

Factors affecting kidney function and proteinuria among HIV-positive (HIV+) and HIV-negative (HIV-) persons need better characterization.

METHODS

We evaluated estimated glomerular filtration rate (eGFR, ml/min per 1.73 m) changes, proteinuria prevalence (a urine protein-to-creatinine ratio of ≥0.2 at two consecutive visits) and associated factors among HIV+ and HIV- men.

RESULTS

There were 917 HIV+ men receiving HAART, 159 HIV+ men not receiving HAART, and 1305 HIV- men seen from October 2003 to September 2014. Median annual eGFR change was -0.5, -0.8% for HIV+ and -0.3% for HIV- men (P < 0.001). Factors significantly (P < 0.05) associated with more than 3% annual eGFR decline were HAART receipt (but no specific antiretroviral drug), age more than 50, hypertension, diabetes, current smoking. Proteinuria existed in 14.9% of visit-pairs among HAART recipients, 5.8% among non-HAART recipients, and 1.9% among HIV- men, and was associated with subsequent annual more than 3% eGFR decline (odds ratio 1.80, P < 0.001). Proteinuria-associated factors also included HAART use (vs. HIV-), age at least 50 (vs. <40), diabetes, hypertension, current smoking, hepatitis C virus-infection (all P < 0.05) and, among HIV+ men, lower CD4 cell count, didanosine, saquinavir, or nelfinavir use (all P < 0.05). After adjusting for proteinuria, among HAART users, having a detectable HIV RNA, cumulative use of tenofovir disoproxil fumarate, emtricitabine, ritonavir, atazanavir, any protease inhibitor, or fluconazole were associated with more than 3% annual eGFR decline.

CONCLUSION

Longitudinal kidney function decline was associated with HAART use but no individual antiretroviral drug, and traditional kidney disease risks. Proteinuria was nearly seven times more common in HAART-treated men than HIV- men, reflected recent eGFR decline and predicted subsequent eGFR decline.

HIV and renal disease: a contemporary review

The presence of human immunodeficiency virus (HIV)-related kidney disease is an important cause of mortality and morbidity. HIV infection induces renal injury by direct cytotoxicity or immune complex-mediated glomerulonephritis in patients with genetic susceptibility factors. In the last decades, with the development and diffusion of combination antiretroviral therapy, which has prolonged patient survival, there has been a shift in the spectrum of renal diseases in HIV-infected patients, with the decrease of glomerular diseases and increase in the role of nephrotoxicity and co-morbidities. This review provides a contemporary and critical review on the main renal syndromes occurring in HIV-infected patients.

Prevalence of Persistent Renal Dysfunction in Perinatally HIV-infected Thai Adolescents

BACKGROUND

Persistent renal dysfunction (PRD) has been reported in up to 22% of perinatally HIV-infected adolescents (PHAs) in the United States and Europe. There are limited data available on PRD among PHAs in resource-limited settings regarding access to antiretroviral therapy (ART) at more advanced HIV stages.

METHODS

We retrospectively described the prevalence of PRD and associated factors in a Thai PHA cohort. Inclusion criteria were current age ≥10 years old and at least 2 serum creatinine (Cr) measurements after ART initiation. Cr and urine examination were performed every 6-12 months. PRD was defined as having ≥2 measurements of low estimated glomerular filtration rate (eGFR); either <60 mL/min/1.73 m2 or elevated Cr for age and eGFR 60-89 mL/min/1.73 m2, or proteinuria (dipstick proteinuria ≥1+). Factors associated with PRD were analyzed using a multivariate logistic regression analysis.

RESULTS

This study included 255 PHAs with median (interquartile range) age of 16.7 (14.5-18.8) and ART duration of 10.3 (7.1-12.4) years. Fifty-six percentage used boosted protease inhibitor (bPI)-based regimens, and 63% used tenofovir disoproxil fumarate (TDF). The overall PRD prevalence was 14.1% [95% confidence interval (CI): 10.1-19.0]; low eGFR 6.7%, proteinuria 3.5% and both 3.9%. Among 109 users of TDF with bPI, 22.9% had PRD and 2.8% discontinued/adjusted dosing of TDF because of nephrotoxicity. Factors associated with PRD were age 10-15 years old (adjusted odd ratio (aOR): 10.1, 95% CI: 4.1-25.2), male (aOR: 3.2, 95% CI: 1.4-7.7), CD4 nadir <150 cells/mm (aOR: 2.6, 95% CI: 1.1-6.1) and use of TDF with bPI (aOR: 9.6, 95% CI: 3.2-28.9).

CONCLUSIONS

PRD is common among PHAs. Almost one-fifth of adolescents using TDF with bPI had PRD. These adolescents should be a priority group for renal monitoring.

Vitamin D Status and Kidney Function Decline in HIV-Infected Men: A Longitudinal Study in the Multicenter AIDS Cohort Study

Vitamin D may play an important role in a range of disease processes. In the general population, lower vitamin D levels have been associated with kidney dysfunction. HIV-infected populations have a higher risk of chronic kidney disease. Few studies have examined the link between lower vitamin D levels and kidney function decline among HIV-infected persons. We investigated the associations of serum 25-hydroxyvitamin D [25(OH)D] and 1,25-dihydroxyvitamin D [1,25(OH)₂D] with kidney function decline in a cohort of HIV-infected white and black men under highly active antiretroviral therapy treatment in the vitamin D ancillary study of the Multicenter AIDS Cohort Study. The associations of 25(OH)D and 1,25(OH)₂D with annual change in estimated glomerular filtration rate (eGFR) were evaluated using linear mixed effects models. This study included 187 whites and 86 blacks with vitamin D measures and eGFR ≥60 ml/min/1.73 m² at baseline. Over a median follow-up of 8.0 years, lower 25(OH)D levels were significantly associated with faster eGFR decline in whites (adjusted annual change in eGFR, tertile 1: -2.06 ml/min/1.73 m² vs. tertile 3: -1.23 ml/min/1.73 m², p trend .03), while no significant association was detected in blacks. Lower 1,25(OH)₂D was associated with faster kidney function decline in both whites and blacks, although the estimates were not statistically significant. In conclusion, lower 25(OH)D levels were significantly associated with faster eGFR decline in a cohort of HIV-infected white men, but not in those with black ancestry. Further research is warranted to investigate the association of 25(OH)D and 1,25(OH)₂D with kidney function decline in larger and ethnically diverse populations.

The renal pathological findings in Japanese HIV-infected individuals with CKD: a clinical case series from a single center

BACKGROUND

Chronic kidney diseases (CKD) have emerged as a significant cause of morbidity and mortality in patients infected with human immunodeficiency virus (HIV). However, the detailed study of renal pathological findings currently remains unclear in these Japanese patients.

METHODS

A retrospective cohort study was undertaken to investigate renal pathological findings between January 1996 and July 2016. Our study included 20 Japanese HIV-infected patients with CKD; 10 cases had undergone renal biopsies, and 10 cases had undergone autopsies, respectively. Moreover, in the 10 biopsied patients, their clinical courses as well as renal outcomes after renal biopsy were also reviewed.

RESULTS

All of the patients had received combination antiretroviral therapy (cART). The 10 biopsy cases (mean age, 54 ± 14 years and duration of cART, 8 ± 5 years) included three cases of diabetic nephropathy (DMN), two of IgA nephropathy, two of cART-induced tubulointerstitial nephritis (TIN), one of minimal change disease, one case of only finding intrarenal arterioles, and one case without abnormal findings. Among those patients, their clinical courses were preferable except for in the DMN cases. In the autopsy cases (mean age, 52 ± 10 years and duration of cART, 5 ± 5 years), no distinct mesangial or membranous abnormalities were detected. Mild to moderate tubulointerstitial atrophies were observed in six cases. Intrarenal arteriosclerosis was identified in nine cases, and the proportion of global glomerulosclerosis seen was 8.4 ± 12.5%/100 glomeruli.

CONCLUSION

DMN and cART-induced TIN was noted in the biopsy cases. In the autopsy cases, renal arteriosclerosis, global glomerulosclerosis, and tubulointerstitial atrophy were remarkable. Early diagnosis of kidney diseases should be crucial to introduce optimal management, including controlling rigorous comorbidities and appropriate use of cART, to prevent further progression of CKD.

Medication-Induced Interstitial Nephritis in the 21st Century

Interstitial nephritis is an immune mediated form of tubulointerstitial kidney injury that may occur secondary to drugs, autoimmune disease, infections, and hematologic disorders or as a reactive process. Drug-induced acute interstitial nephritis (DI-AIN) occurs in 0.5%-3% of all kidney biopsies and in 5%-27% of biopsies performed for acute kidney injury. Drugs are implicated in 70%-90% of biopsy-proved IN with a prevalence of 50% in less developed to 78% in more developed countries. DI-AIN typically is idiosyncratic because of a delayed hypersensitivity reaction, although some chemotherapeutic agents are permissive for immune upregulation and injure the kidney in a dose-related manner. Antibiotics are the most implicated class of medication in DI-AIN, followed by proton pump inhibitors, nonsteroidal anti-inflammatory agents, and 5-aminosalicylates. Diuretics, allopurinol, phenytoin and other anti-seizure medications, and H2 receptor antagonists are known offenders while chemotherapeutic agents are an under-recognized cause. The symptoms of DI-AIN are variable and often not specific; thus, kidney biopsy is required to make a firm diagnosis. The incidence of DI-AIN appears to be increasing, particularly in the elderly in whom kidney biopsy is underused, and identification of the offending agent may be complicated by polypharmacy. As rapid drug discontinuation may improve prognosis, the possibility of DI-AIN should always be considered in a patient with acute kidney injury.

Efficacy and safety of "unboosting" atazanavir in a randomized controlled trial among HIV-infected patients receiving tenofovir DF

OBJECTIVES

To assess safety and efficacy of a switch to unboosted atazanavir (ATV) among HIV-infected adults receiving ATV/ritonavir (r) and tenofovir disoproxil fumarate (TDF).

METHODS

HIV-infected adults with viral load (VL) <40 copies/mL at screening and <150 copies/mL consistently for ≥3 months while receiving a regimen including ATV/r and TDF were randomized to continue ATV/r 300/100 mg daily (control) or change to ATV 400 mg daily (switch), while maintaining their TDF backbone. The primary outcome was proportion of subjects without treatment failure (regimen switch or VL > 200 copies/mL twice consecutively) at 48 weeks.

RESULTS

Fifty participants (46 male, median age 47 years) were randomized, 25 to each arm. At week 48, treatment success occurred in 76% in the control arm and 92% in the switch arm (ITT, p = 0.25). ATV trough levels at week 9 were higher in controls (median 438 ng/mL) than in the switch arm (median 124 ng/mL) (p = 0.003), as was total bilirubin at week 48 (median 38 μmol/L and 28 μmol/L, respectively; p = 0.02). Estimated glomerular filtration rate (eGFR) decreased in the control arm (p = 0.007), but did not change in the switch arm. At week 48, eGFR was higher in the switch arm (median 96 mL/min) than in the control arm (median 85 mL/min) (p = 0.035), but the arms were similar with respect to fasting glucose, C-reactive protein, and lipid parameters.

CONCLUSIONS

Switching from ATV/r to unboosted ATV appears to be safe and effective in selected virologically suppressed patients receiving TDF-containing regimens, and may have favorable effects on bilirubin and renal function.

HIV and kidney diseases: 35 years of history and consequences

Kidney diseases in human immunodeficiency virus (HIV)-infected patients are often misdiagnosed. Despite reductions in morbidity and mortality owing to widespread use of highly effective combination antiretroviral therapy (cART), acute kidney injury (AKI) and chronic kidney disease (CKD) are still more common in these patients than in the general population, and are associated with poor health outcomes. HIV-associated nephropathy and HIV immune complex kidney diseases are the more recognizable HIV-related kidney diseases. However, a broad spectrum of kidney disorders related or not directly related with HIV infection can be observed, including cART-induced AKI, CKD, proximal tubular dysfunction, crystalluria and urolithiasis, among others. This review summarizes the major epidemiologic studies of kidney diseases in HIV-infected patients, discusses novel approaches that may potentially limit nephrotoxicity such as the use of tenofovir alafenamide, and outlines current screening measures for early diagnosis of kidney dysfunction or tubular damage, and for accurate detection of increased risk for acute or chronic kidney diseases.

Effects of a switch from tenofovir- to abacavir-based antiretroviral therapy, with or without atazanavir, on renal function

Introduction

Tenofovir disoproxil fumarate (TDF)–associated renal dysfunction may abate when TDF is replaced with abacavir (ABC). The extent to which the third drug atazanavir contributes to renal dysfunction is unclear.

Methods

A retrospective analysis was conducted on adults who had plasma viral load (pVL)<200 copies/mL for≥six months while receiving TDF/lamivudine (3TC) – or TDF/emtricitabine (FTC)–based antiretroviral therapy (ART), then switched to ABC/3TC while retaining the third drug in the ART regimen. CD4, pVL, creatinine, estimated glomerular filtration rate (eGFR), serum phosphorus, urine albumin to creatinine ratio and serum lipids were compared between pre-switch baseline and 3, 6 and 12 months after the switch to ABC.

Results

A total of 286 patients switched from TDF to ABC between 2004 and 2014: 232 (81%) male, median age 48 years (interquartile range (IQR) 42, 56). The third drug was atazanavir (± ritonavir) in 141 (49%) cases. The pVL was<50 copies/mL in 93 to 96% at all time points. Median serum creatinine was 93 µmol/L (IQR 80–111) at baseline and decreased to 88 µmol/L (IQR 78–98) at 12 months after the switch to ABC. Median eGFR increased from 74 (IQR 60–88) mL/min at baseline to 80 mL/min (IQR 69–89) at 12 months. Results were not significantly different between patients on atazanavir versus those on another third drug.

Conclusions

Viral suppression was maintained among patients who switched from TDF/3TC or TDF/FTC to ABC/3TC. Serum creatinine and eGFR improved up to 12 months after switching to ABC/3TC, irrespective of whether or not patients were also receiving atazanavir±ritonavir.

Co-administration of elvitegravir/cobicistat/tenofovir disoproxil fumarate/emtricitabine and atazanavir in treatment-experienced HIV patients

We report the use of elvitegravir 150 mg/cobicistat 150 mg/tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg (EVG/COBI/TDF/FTC) once daily, in addition to once-daily atazanavir (ATV) 300 mg, in treatment-experienced patients with human immunodeficiency virus (HIV). Due to limited data available on the co-administration of these agents, our objective was to evaluate and monitor safety and efficacy of this regimen in patients who developed resistance or intolerance to conventional antiretroviral therapy (ART). This short report included offenders incarcerated in the Illinois Department of Corrections who were ≥18 years, HIV-infected, had documented antiretroviral resistance, and received EVG/COBI/TDF/FTC + ATV once daily. Based on previous ART, resistance patterns and current medications, seven patients were initiated on once-daily therapy consisting of EVG/COBI/TDF/FTC and ATV. Due to extensive resistance, two of the seven patients were also started on abacavir (ABC) 600 mg daily in addition to EVG/COBI/TDF/FTC and ATV. Of the seven patients, one had ART changed due to concerns of resistance based on a genotype, one experienced a decline in renal function that warranted a change in therapy, and one is currently virologically suppressed on a combination of EVG/COBI/TDF/FTC, ATV, and ABC. The remaining four patients remain virologically suppressed on EVG/COBI/TDF/FTC + ATV. Therapy consisting of EVG/COBI/TDF/FTC and ATV may be a viable option for some treatment-experienced HIV-infected patients. Further studies evaluating the safety, efficacy, and pharmacokinetics of this therapy are warranted, given the lack of information currently available.

Nephrology consultations incorporated into HIV care - non-compliance is an important issue

Although infrequent, kidney disease is a potentially serious co-morbidity among human immunodeficiency virus (HIV)-infected patients. The spectrum of renal impairment is very wide from clinically insignificant to end stage renal disease and often requires nephrologist's consultation. Therefore, we established combined renal and HIV care in the HIV Out-Patient Clinic in Warsaw. Medical records of patients consulted by nephrologist from March 2014 to March 2015 were included in analyses. Patients changing medication without consulting the physician or persistently not coming for follow-up visits were defined as non-compliant. In statistical analyses, non-parametric tests and logistic regression models were used as appropriate. In total, 100 patients were consulted by a nephrologist during the study period. All patients were white Europeans, 88 (88%) male, 42 (42%) infected through men having sex with men and 16 (16%) through intravenous drug users. Fifteen (15%) patients had hepatitis C virus (HCV) infections and 11 (11%) confirmed with positive HCV RNA. The most common reasons for referral were proteinuria and increased serum creatinine. In 6 out of 31 patients (19.3% of those referred for increased creatinine level) elevated serum creatinine was due to illegal substances or diet supplements use. Fifty-seven (57%) of patients were non-compliant. In univariate logistic regression models, all tested factors were non-significant. In most cases, patients were referred to nephrologist due to possible link between laboratory abnormalities and antiretroviral treatment. In one out of five cases, elevated creatinine level was linked with substance/dietary abuse. Poor compliance is an important problem in integrated nephrological care, however we were not able to identify any factors associated with non-compliance.

Increased non-HDL-C level linked with a rapid rate of renal function decline in HIV-infected patients

BACKGROUND

The risk of developing CKD is increased in HIV-infected patients; however, the relationship between renal function decline and lipid abnormalities currently remains unclear in these patients.

METHODS

A retrospective cohort study was conducted on 661 HIV-infected patients, whose estimated glomerular filtration rates (eGFRs) were consecutively measured over 6 years. The rate of declines in eGFR per year was calculated, with decreases being evaluated using a linear mixed effect model. The distribution of decreases in eGFR ≥ 30 % from baseline during the follow-up period was compared across quartiles of non-high-density lipoprotein cholesterol (HDL-C) levels using the Cochran-Armitage test. A multivariate logistic regression model was built to examine the relationship between dyslipidemia and decreases in eGFR.

RESULTS

The prevalence of CKD increased from 8.5 to 21.2 % during the follow-up. The average of 6 annual eGFR decline rates was 2.01 ± 0.09 ml/min/1.73 m²/year, which was more than 6-fold higher than that of age-matched controls. The distribution of decreases in eGFR significantly increased across the quartiles of non-HDL-C (p value for trend = 0.0359). Non-HDL-C levels greater than the median value of the cohort were identified as a significant risk factor for decreased eGFR [odds ratio (95 % confidence interval), 1.77 (1.07-3.00)].

CONCLUSION

Increased non-HDL-C levels are a risk factor for renal function decline in HIV-infected patients.

Multiple facets of HIV-associated renal disease

HIV infection has a broad spectrum of renal manifestations. This study examined the clinical and histological manifestations of HIV-associated renal disease, and predictors of renal outcomes. Sixty-one (64% male, mean age 45 years) HIV patients were retrospectively evaluated. Clinical presentation and renal histopathology were assessed, as well as CD4 T-cell count and viral load. The predictive value of histological lesion, baseline CD4 cell count and viral load for end-stage renal disease (ESRD) or death were determined using the Cox regression model. The outcomes of chronic kidney disease (CKD) and ESRD or death were evaluated by baseline CD4 cell count. The percent distribution at initial clinical presentation was non-nephrotic proteinuria (54%), acute kidney injury (28%), nephrotic syndrome (23%), and chronic kidney disease (22%). Focal segmental glomerulosclerosis (28%), mainly the collapsing form (HIVAN), acute interstitial nephritis (AIN) (26%), and immune complex-mediated glomerulonephritis (ICGN) (25%) were the predominant renal histology. Baseline CD4 cell count ≥ 200 cells/mm3 was a protective factor against CKD (hazard ratio=0.997; 95%CI=0.994-0.999; P=0.012). At last follow-up, 64% of patients with baseline CD4 ≥ 200 cells/mm3 had eGFR >60 mL·min-1·(1.73 m2)-1 compared to the other 35% of patients who presented with CD4 <200 cells/mm3 (log rank=9.043, P=0.003). In conclusion, the main histological lesion of HIV-associated renal disease was HIVAN, followed by AIN and ICGN. These findings reinforce the need to biopsy HIV patients with kidney impairment and/or proteinuria. Baseline CD4 cell count ≥ 200 cells/mm3 was associated with better renal function after 2 years of follow-up.

Small vessel microembolization and acute glomerulonephritis following infection of aesthetic filler implants

Background

The systemic consequences of esthetic filler injections are poorly understood.

Case presentation

We report a patient with a past history of subcutaneous injection of aesthetic filler material in the lower legs, who presented with post-infectious glomerulonephritis following necrotic leg ulcers at the injection site. Kidney biopsy revealed the presence of translucent, non-birefringent microspherical bodies compatible with polymethylmetacrylate (PMMA) microspheres in some capillary lumens. This had not previously been described. PMMA is a biphasic aesthetical filler composed of polymethylmetacrylate microspheres suspended in a biodegradable bovine collagen carrier. The solid phase (PMMA microspheres) persists in tissues for years. Although PMMA was thought to not disseminate systemically, tissue necrosis may have favored systemic dissemination of the microspheres, although entry in the circulation and microembolization at the time of administration cannot be ruled out.

Conclusions

In conclusion, aesthetic filler implants may cause microembolization into small vessels. Recognition of the characteristic morphology may expedite diagnosis and avoid unnecessary further testing.

HIV and the kidney in the acute medical unit

Acute kidney injury (AKI) is encountered commonly in HIV-positive patients admitted to the acute medical unit. The spectrum of AKI has changed in the era of combination anti-retroviral therapy, and now includes adverse effects of commonly used anti-retroviral drugs in addition to traditional precipitants such as severe sepsis or exposure to nephrotoxic antimicrobials. An accurate diagnosis requires careful integration of clinical data including volume status, history of potentially nephrotoxic exposures and consideration of immuno-virological status. This article provides an overview of common causes of AKI in HIV and presents a framework by which the acute care physician may approach the finding of an elevated serum creatinine in a patient with HIV.