Risk factors for indinavir-related renal colic in HIV patients: predictive value of indinavir dose/body mass index

The HIV protease inhibitor darunavir prevents kidney injury via HIV-independent mechanisms

HIV-associated nephropathy (HIVAN) is a rapidly progressive kidney disease that is caused by HIV infection of renal epithelial cells with subsequent expression of viral genes, including vpr. Antiretroviral therapy ameliorates HIVAN without eradicating HIV from the kidneys and the mechanism by which it protects kidneys is poorly understood. Since HIV protease inhibitors have "off target" cellular effects, we studied whether darunavir, the most commonly prescribed protease inhibitor, protects kidneys from HIV-induced injury via mechanisms independent of HIV protease and viral replication. Renal epithelial cells were transduced with lentiviruses encoding HIV (lacking protease and reverse transcriptase), Vpr, or vector control. Darunavir attenuated HIV and Vpr-induced activation of Stat3, Src, Erk, and cytokines, which are critical for HIVAN pathogenesis. We then studied HIV-transgenic mice, which develop HIVAN in the absence of HIV protease or reverse transcriptase. Mice were treated with darunavir, zidovudine, darunavir + zidovudine, or control. Darunavir and darunavir + zidovudine reduced albuminuria and histologic kidney injury and normalized expression of dysregulated proteins. RNA-seq analyses demonstrated that darunavir suppressed HIV-induced upregulation of immune response genes in human kidney cells. These data demonstrate that darunavir protects against HIV-induced renal injury via mechanisms that are independent of inhibition of HIV protease.

[Nephrotoxicity of antiretrovirals other than tenofovir]

The remarkable improvement of the outcome of HIV infection came with the price of substantial toxicity of some antiretrovirals. The first molecules used to treat HIV included an important nephrotoxicity. Zalcitabine, stavudine and didanosine can induce severe lactic acidosis. Lactate production is enhanced and the renal capacity to regulate pH is overwhelmed. However, this side effect is not due to a direct dysfunction of the kidneys. Zalcitabine was withdrawn from the market because of this risk. Indinavir, a protease inhibitor, is soluble only in very acidic solutions. Consequently, the small fraction that is excreted in the urine precipitates and can be responsible for uro-nephrolithiasis, leukocyturia, cristalluria, obstructive acute kidney failure, and acute or chronic interstitial nephritis. This is the reason why indinavir is almost not prescribed nowadays, even if it is still marketed. In addition to the direct nephrotoxicity of some antiretrovirals, anti-HIV treatment also includes a toxicity which pathophysiology is not completely elucidated. This nephrotoxicity is the consequence of organ accelerated ageing and of an increased vascular risk. Kidney vascularization (from renal arteries to capillaries) is essential to kidney function and all cardiovascular risks are also renal risks. It is now clearly established that combined antiretroviral treatment increases the vascular risk. A better comprehension of the links between HIV infection, its treatment and very long-term kidney risk is needed to improve the complex management of patients who have now cumulated several decades of HIV infection and treatment with various toxicities.

Renal effects of non-tenofovir antiretroviral therapy in patients living with HIV

A review of literature published regarding non-tenofovir antiretroviral agents causing renal adverse effects was conducted. The literature involving renal adverse effects and antiretroviral therapy is most robust with protease inhibitors, specifically atazanavir and indinavir, and includes reports of crystalluria, leukocyturia, nephritis, nephrolithiasis, nephropathy and urolithiasis. Several case reports describe potential nephropathy (including Fanconi syndrome) secondary to administration of abacavir, didanosine, lamivudine and stavudine. Case reports documented renal events such as acute renal failure, nephritis, proteinuria and renal stones with efavirenz administration. Regarding rilpivirine, a small increase of serum creatinine levels (SCr) was found in clinical trials; however, the clinical significance and impact on actual renal function is unknown. The integrase strand transfer inhibitors and enfuvirtide have a relatively safe renal profile, although studies have shown dolutegravir and raltegravir cause mild elevations in SCr without an impact on actual renal function. This is similar to the reaction observed with cobicistat, the pharmacokinetic enhancer frequently given with elvitegravir.

The impact of societal changes on patterns of urolithiasis

PURPOSE OF REVIEW

The purpose of the present review is to track changes in prevalence and composition of stone disease as a result of lifestyle changes over the past century.

RECENT FINDINGS

Increasing rates of obesity, diabetes mellitus and metabolic syndrome have resulted in increasing rates of nephrolithiasis among women, decreasing the male-to-female ratio from 1.3: 1 to 1.7: 1. Urine composition results have revealed a decrease in urinary pH (<5.5) and an increase in urinary uric acid supersaturation. This has resulted in increased rates of uric acid stones. Modern bariatric surgeries have further increased the risk of calcium oxalate stone formation. Offending agents, intentionally or unintentionally added to food or drug products, have also led to the appearance of previously unrecognized stone types, that is, melamine and indinavir calculi.

SUMMARY

Societal changes have had a tremendous impact on stone prevalence and composition. Prompt healthier lifestyle education as well as tighter quality control in the Food and Drug Industry is paramount to reducing nephrolithiasis rates and its complications.

The impact of hepatitis C virus coinfection on HIV-related kidney disease: a systematic review and meta-analysis

BACKGROUND

In the era of antiretroviral therapy, non-AIDS complications such as kidney disease are important contributors to morbidity and mortality.

OBJECTIVE

To estimate the impact of hepatitis C coinfection on the risk of kidney disease in HIV patients.

DESIGN AND METHODS

Two investigators identified English-language citations in MEDLINE and Web of Science from 1989 through 1 July 2007. References of selected articles were reviewed. Observational studies and clinical trials of HIV-related kidney disease and antiretroviral nephrotoxicity were eligible if they included at least 50 subjects and reported hepatitis C status. Data on study characteristics, population, and kidney disease outcomes were abstracted by two independent reviewers.

RESULTS

After screening 2516 articles, 27 studies were eligible and 24 authors confirmed or provided data. Separate meta-analyses were performed for chronic kidney disease outcomes (n = 10), proteinuria (n = 4), acute renal failure (n = 2), and indinavir toxicity (n = 5). The pooled incidence of chronic kidney disease was higher in patients with hepatitis C coinfection [6.2 versus 4.0%; relative risk 1.49, 95% confidence interval (CI) 1.08-2.06]. In meta-regression, prevalence of black race and the proportion of patients with documented hepatitis C status were independently associated with the risk of chronic kidney disease. The relative risk associated with hepatitis C coinfection was significantly increased for proteinuria (1.15; 95% CI 1.02-1.30) and acute renal failure (1.64; 95% CI 1.21-2.23), with no significant statistical heterogeneity. The relative risk of indinavir toxicity was 1.59 (95% CI 0.99-2.54) with hepatitis C coinfection.

CONCLUSION

Hepatitis C coinfection is associated with a significant increase in the risk of HIV-related kidney disease.

Hypercalciuria is the main renal abnormality finding in Human Immunodeficiency Virus-infected children in Venezuela

Kidney involvement in children with Human Immunodeficiency Virus (HIV) infection is increasing in prevalence in parallel with the longer survival of HIV-infected patients and the side-effects of new antiretroviral drugs. However, there are only a few reports describing renal tubular disorders in HIV+ children. This is a cross-sectional, case series study evaluating kidney disease in 26 Venezuelan HIV-infected children. The study cohort consisted of 15 girls and 11 boys, with a median age of 5.9 years (25-75th percentile: 3.6-7.8), who had been treated with antiretrovirals for 2.8 +/- 0.4 years, Overall, the patients were short for their age and gender (Z-height: -3.1; 25-75th percentile: -4.94 to -1.98), and 15 showed signs of mild to moderate malnutrition. All of the children had a normal estimated glomerular filtration rate (136 +/- 22.6 ml/min/1.73 m2), and glomerular involvement was only observed in one patient with isolated proteinuria. None had nephromegaly. In contrast, tubular disorders were commonly found. Hypercalciuria was detected in 16 of the patients (UCa/Cr = 0.28; 25-75th percentile: 0.17-0.54 mg/mg), with five of these showing crystalluria. Eight children showed hyperchloremia, and three had frank metabolic acidosis. Kidney stones were absent in all, but one boy had bilateral medullary nephrocalcinosis. Conclusion, in Venezuelan children, HIV infection per se, or its specific treatment, was commonly associated with renal tubular dysfunction, especially hypercalciuria and acidosis, potentially leading to nephrocalcinosis and growth impairment. We recommend renal tubular evaluation during the follow-up of children with HIV infection.

HIV-AIDS: urologic considerations

The prevalence of HIV continues to grow in the United States and worldwide. HIV-positive patients experience many genitourinary disease processes. With improvements in HIV therapy, patients have questions and concerns pertaining to their quality of life. This article reviews conditions such as HIV-related urinary tract infections, urolithiasis, voiding dysfunction, fertility, sexual dysfunction, HIV-related nephropathy, malignancies, and occupational exposure and prophylaxis. Knowledge of the various HIV manifestations of genitourinary conditions and their treatment options benefits clinicians and improves patient outcomes.

Indinavir: the forgotten HIV-protease inhibitor. Does it still have a role?

Indinavir is one of four first-generation HIV-protease inhibitors and was the most popular amongst them in the late 1990s. It was initially licensed for use alone, given three times daily, administered away from meals and together with at least 1.5 litres of fluid per day. In clinical practice, it became common for clinicians to prescribe it with a ritonavir pharmacokinetic 'boost' to remove the food restriction, reduce the pill burden and enable a more convenient twice-daily dosing schedule. However, at a ritonavir-boosted dosing schedule of indinavir/ritonavir 800/100 mg b.i.d., the regimen proved toxic and poorly tolerable, and its use diminished as newer, better tolerated PIs became available. Recent research has suggested that ritonavir-boosted indinavir administered at lower doses, particularly indinavir/ritonavir 400/100 mg b.i.d., retains potency and is considerably less toxic. As a result, there is interest in its application in resource-constrained settings.

HIV-associated renal disorders: recent insights into pathogenesis and treatment

Renal electrolyte disorders, acute renal failure, and a variety of chronic renal diseases are common in HIV-infected patients. Glomerular disorders include IgA nephropathy, cryoglobulinemia, amyloidosis, and a lupus-like immune complex glomerulopathy. The most attention has been focused on collapsing glomerulopathy associated with nephrotic syndrome and progressive renal failure, which appears to be unique for patients with HIV/AIDS, called HIV-associated nephropathy (HIVAN), and it occurs predominantly in African American patients. Investigations in humans and in a transgenic mouse model reveal direct infection of renal epithelial cells by HIV and toxic cellular and immunologic processes mediated by HIV glycoproteins as the principal pathophysiology of HIVAN. Highly active antiretroviral treatment may be associated with an improved renal outcome and even reversal of kidney disease in some patients. Treatment with angiotensin-converting enzyme inhibitors may avert progression of HIVAN to end-stage kidney disease and result in superior patient and kidney survival as compared with untreated patients.

HAART-related nephropathies in HIV-infected patients

There is no doubt that highly active antiretroviral therapy (HAART) has been the most important progress in the therapy of human immunodeficiency virus (HIV)-infected patients in the last decade. A growing number of observations suggest that the beneficial effects of HAART also include improvement of HIV-related renal complications. Consequently, the cohort of HIV-infected patients requiring HAART has increased and includes patients with preexisting nephropathies, whether related or unrelated to HIV infection. However, some antiretroviral drugs may have renal- and life-threatening side-effects, especially if underlying renal abnormalities exist. In this review, we focus on those aspects that require particular attention in preventing new health complications in HIV-infected patients.

Indinavir/ritonavir-based therapy in HIV-1-infected antiretroviral therapy-naive patients: comparison of 800/100 mg and 400/100 mg twice daily

Objectives To compare the efficacy and tolerability of indinavir (IDV)/ritonavir (RTV) at 800/100 and 400/100 mg twice daily (bid) in antiretroviral therapy (ART)-naive patients. Methods An open comparison of two groups of ART-naive patients treated with IDV/RTV 800/100 or 400/100 mg bid plus two nucleoside analogues was carried out. Viral load, CD4 cell count and tolerability were measured at baseline and at weeks 4, 12, 24 and 48. IDV plasma concentrations were measured retrospectively. Results A total of 107 patients were included in the study. Of these, 57 were treated with 800/100 and 50 with 400/100 mg IDV/RTV bid. At week 48, a viral load of <50 HIV-1 RNA copies/mL was achieved by 77 and 64% of the patients, respectively, and the median CD4 cell count increases were +171 and +164 cells/muL (intent-to-treat; P not significant), respectively. Side effects leading to protease inhibitor discontinuation occurred in 61% of subjects in the 800/100 mg group vs. 20% in the 400/100 mg group (P<0.0001). Switching from 800/100 to 400/100 mg dosage improved adverse events in 16 of 20 patients. IDV concentrations were above 0.15 mg/L in 89% of the 28 patients tested in the 400/100 mg group. Conclusions Indinavir/ritonavir 400/100 mg bid provided the same efficacy as 800/100 mg bid at 48 weeks in an ART-naive population, but safety and tolerance were significantly better for 400/100 mg, while convenience was also improved and cost was reduced.

Indinavir Plasma Concentration and Adherence Score Are Codeterminant of Early Virologic Response in HIV-Infected Patients of the APROCO Cohort

To study the respective roles of indinavir concentrations and treatment adherence as predictors of early virologic response, we analyzed the patients of the APROCO cohort treated by indinavir 800 mg TID during the first 4 months. Minimum (Cmin), maximum (Cmax), and the ratio of the measured to expected concentrations (CR) were estimated for each patient at M4, from a population pharmacokinetic analysis of all data. The relationship among virologic success at M4 [plasma HIV RNA (VL) <500 copies/mL], baseline characteristics, estimated indinavir concentrations, and adherence score measured by a self-administered questionnaire, was analyzed by multivariate logistic regression. In the 216 studied patients, baseline median HIV RNA was 4.4 log10 copies/mL, and CD4 cell count was 309/mm. Virologic success was achieved in 195 (90%) patients; it was independently related to baseline viral load (OR = 0.524, CI 0.29-0.93; P = 0.03), antiretroviral treatment naive status (OR = 3.89, CI 1.29-11.76; P = 0.01), and indinavir Cmin (OR = 1.06, CI 1.02-1.10; P = 0.004) when adherence score was not included in the model, whereas full adherence was the only independent related factor when included in the model (OR = 8.8, 95% CI 2.85-27.3; P < 10). In the 168 fully adherent patients, virologic success was more frequent in patients with shorter duration of antiretrovirals at baseline (P = 0.03), lower baseline HIV RNA (P = 0.03), and higher indinavir CR (P < 10); the most discriminating Cmin cut-off was 194 ng/mL. Data on the relationship between indinavir plasma concentration and virologic success are therefore misleading without a concomitant assessment of adherence. These data suggest that any strategy of therapeutic drug monitoring must imply first a combined evaluation of plasma concentrations and adherence level and second an intervention target based on the results of both assessments.