HAART-related nephropathies in HIV-infected patients

Methanol Crude Peel Extract of P. granatum Prevents Oxidative Damage in Kidneys of Rats Exposed to Highly Active Antiretroviral Therapy

Background

Highly Active Antiretroviral Therapy (HAART) has been linked to oxidative damage to kidney cells leading to renal disease in people living with HIV/AIDS on HAART treatment. The toxic effects of HAART affect the patients' quality of life leading to poor adherence to their regimen. Therefore, the purpose of this study was to investigate the nephron-protective activity of methanol crude peel extract of Punica granatum (MPEPG) in HAART-administered Wistar rats.

Methods

Thirty male albino Wistar rats weighing between 180-200g were randomly divided into six groups of five rats each. Group one served as normal control and was given distilled water only. Group two serves as a negative control and was given HAART at a dosage of 64 mg/kg. Groups 3 and 4 were given 100 and 400 mg/kg of MPEPG, respectively, while groups 5 and 6 were given MPEPG dosages of 100 and 400 mg/kg along with HAART, respectively, for 40 days. The rats were sacrificed under halothane anaesthesia, and the kidneys were removed for histological evaluation, while blood samples were analyzed for biochemical parameters.

Results

In the HAART (TLD) treated group, there was a significantly high amount of MDA and a lower level of the antioxidant enzymes SOD and CAT. Biochemical analysis revealed that animals treated with HAART (TLD) had significantly higher levels of urea and creatinine, which are biomarkers of kidney damage than the normal control animals. In contrast, all the kidney function markers were returned to normal levels in the HAART-treated group after administration of methanol crude peel extract of P. granatum. The kidney tissues of animals given HAART had considerable structural damage as revealed by histopathological studies. When HAART-exposed rats were treated with MPEPG, both the biochemical and histological results significantly improved.

Conclusion

Methanol crude peel extract of P. granatum provided effective protection against kidney oxidative injury brought on by HAART because of its anti-oxidant and free radical scavenging properties.

Performance of Creatinine- and Cystatin C-Based Equations for Glomerular Filtration Rate Estimation in HIV-1-Infected Individuals Receiving Dolutegravir + Tenofovir Disoproxil Fumarate + Lamivudine as Initial Antiretroviral Therapy: A Retrospective Observational Study

BACKGROUND

Dolutegravir (DTG) may inhibit organic cation transporter-2 in renal tubules and elevate serum creatinine levels without true renal function deterioration. There are scarce data on the glomerular filtration rate (GFR) equations in Chinese HIV patients with DTG/TDF/3 TC. This retrospective study was to evaluate the changes in creatinine- and cystatin C-based estimated GFR values among Chinese adult HIV patients with initial highly active antiretroviral therapy (HAART) with DTG/TDF/3 TC for 48 weeks.

SETTINGS

Retrospective analysis of Chinese adult HIV patients who received initial HAART with DTG/TDF/3 TC between January 2016 and May 2021.

METHODS

We compared the changes in creatinine-based and cystatin C-based estimated GFR before and 48 weeks after HAART to determine the optimal tool for renal function estimation.

RESULTS

Ninety-five patients [91.58% men; median age, 34 years (interquartile range, 29-44 years)] were enrolled. The median baseline CD4+ cell count was 185 cells/µL [interquartile range, 53-303 cells/µL] and the median baseline viral load was 148,000 copies/mL [interquartile range, 26,800-596,000 copies/mL]. The estimated GFR at 4, 12, and 24 weeks was significantly different than at baseline (P < 0.05) using all 4 equations. Only the GFR estimated using the CKD-EPIcreat and CKD-EPIcys equations was significantly different at 48 weeks of treatment (P < 0.05). The modification of diet in renal disease-based decline of GFR incidence at 4, 12, 24, and 48 weeks of treatment (21.5%, 24.21%, 33.68% and 38.95%, respectively) was higher than that calculated using the other 3 GFR equations.

CONCLUSIONS

The modification of diet in renal disease equation may not be optimal for Chinese HIV-1-infected adults receiving DTG + TDF + 3 TC as the initial antiviral therapy. Clinicians must carefully choose the GFR equation for patients with HIV/hepatitis B virus coinfection.

Associations Between Plasma Immunomodulatory and Inflammatory Mediators With VACS Index Scores Among Older HIV-Infected Adults on Antiretroviral Therapy

The prevalence of age-related comorbidities is increased in people living with HIV, even in those well-controlled on combination antiretroviral therapy (ART). Persistent immune activation and inflammation may play pivotal roles in the pathogenesis; however, the burden of morbidities in the older HIV infected population may be exacerbated and driven by distinct mechanisms. In a cross sectional study of 45 HIV-infected participants 60 years or older, we examined the relationships between 14 immunomodulatory and inflammatory factors and the Veterans Aging Cohort Study (VACS) Index, a metric of multimorbidity and mortality comprised of age, CD4 count, hemoglobin, Fibrosis-4 [FIB-4], and estimated glomerular filtration rate [eGFR], by linear regression analysis. All participants were virally suppressed (<50 HIV RNA copies/mL), on ART, and primarily Caucasian (86.7%), and male (91.1%). Plasma levels of monocyte/macrophage-associated (neopterin, IP-10, sCD163, sCD14, and MCP-1) and glycan-binding immunomodulatory factors (galectin (Gal)-1, Gal-3, and Gal-9) were assessed, as well as inflammatory biomarkers previously linked to the VACS Index (i.e., CRP, cystatin C, TNF-α, TNFRI, IL-6, and D-dimer) for comparison. In regression analysis, higher VACS index scores were associated with higher levels of neopterin, cystatin C, TNFRI, and Gal-9 (all p < 0.05), potentially driven by correlations found with individual VACS components, including age, CD4 count, FIB-4, and eGFR. Gal-9, cystatin C, and TNFRI directly correlated with the extent of multimorbidity. Multiple correlations among markers were observed, suggesting an interplay of overlapping, but distinct, pathways. Collectively, in addition to cystatin C and TNFRI, both galectin-9 and neopterin, independently emerged as novel fluid markers of the VACS Index and burden of comorbidity and may further guide in understanding pathogenic mechanisms of age-related disorders in older HIV-infected individuals on suppressive ART.

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.

Challenges of kidney transplantation in HIV positive recipients

Human immunodeficiency virus (HIV) infection has long been a contraindication to kidney transplantation due to transplant immunosuppression, HIV-associated renal dysfunction, and nephrotoxicity associated with antiretroviral therapy (ART). However, advances in antiretroviral therapies and transplant immunosuppression regimens have allowed patients to successfully undergo kidney transplantation. Emerging data has shown that kidney transplantation may be a viable option for appropriately selected HIV patients with end-stage renal disease (ESRD). In this review, we discuss the indications, immunosuppression protocols, and outcomes of kidney transplantation in HIV patients.

Risk factors and co-morbidities associated with changes in renal function among antiretroviral treatment-naïve adults in South Africa: A chart review

INTRODUCTION

Our systematic scoping review has demonstrated a research gap in antiretroviral treatment (ART) nephrotoxicity as well as in the long-term outcomes of renal function for patients on ART in South Africa. Bearing in mind the high prevalence of human immunodeficiency virus (HIV) in South Africa, this is of great concern.

OBJECTIVES

To determine the risk factors and co-morbidities associated with changes in renal function in HIV-infected adults in South Africa.

METHODS

We conducted a retrospective study of 350 ART-naïve adult patients attending the King Edward VIII HIV clinic, Durban, South Africa. Data were collected at baseline (pre-ART) and at six, 12, 18 and 24 months on ART. Renal function was assessed in the 24-month period using the Modification of Diet in Renal Disease equation and was categorised into normal renal function (estimated glomerular filtration rate [eGFR] ≥ 60), moderate renal impairment (eGFR 30-59), severe renal impairment (eGFR 15-29) and kidney failure (eGFR < 15 mL/min/1.73 m2). Generalised linear models for binary data were used to model the probability of renal impairment over the five time periods, controlling for repeated measures within participants over time. Risk ratios and 95% confidence intervals (CI) were reported for each time point versus baseline.

RESULTS

The cohort was 64% female, and 99% were Black. The median age was 36 years. At baseline, 10 patients had hypertension (HPT), six had diabetes, 61 were co-infected with tuberculosis (TB) and 157 patients had a high body mass index (BMI) with 25.4% being categorised as overweight and 19.4% as obese. The majority of the patients (59.3%) were normotensive. At baseline, the majority of the patients (90.4%) had normal renal function (95% CI: 86% - 93%), 7.0% (CI: 5% - 10%) had moderate renal impairment, 1.3% (CI: 0% - 3%) had severe renal impairment and 1.3% (CI: 0% - 3%) had renal failure. As BMI increased by one unit, the risk of renal impairment increased by 1.06 (CI: 1.03-1.10) times. The association of HPT with abnormal renal function was found to be insignificant, p > 0.05. The vast majority of patients were initiated on tenofovir disoproxil fumarate (TDF) (90.6%), in combination with lamivudine (3TC) (100%) and either efavirenz (EFV) (56.6%) or nevirapine (NVP) (43.4%).

CONCLUSION

This study reports a low prevalence of baseline renal impairment in HIV-infected ART-naïve outpatients. An improvement in renal function after the commencement of ART has been demonstrated in this population. However, the long-term outcomes of patients with HIV-related renal disease are not known.

Mortal allies: human immunodeficiency virus and noncommunicable diseases

PURPOSE OF REVIEW

HIV-infected individuals have improved access to antiretroviral therapy. This has resulted in a shift in causes of mortality from infectious diseases to noncommunicable diseases including cardiovascular disease, chronic kidney disease (CKD) and malignancies. This review will look at the epidemiological shift, risk factors for the development of these diseases and examine some of the supporting laboratory diagnostic testing, which may be required.

RECENT FINDINGS

Risk factors for the development of these diseases in HIV-infected patients include underlying genetic predisposition, lifestyle risk factors, chronic inflammation as a consequence of HIV infection, the presence and persistence of opportunistic infections and in some cases, highly active antiretroviral therapy, itself. Morbidity and mortality from HIV-associated conditions are increasing in low-income and middle-income countries (LMICs) with increased prevalence of HIV-associated cancers, cardiovascular disease and CKD.

SUMMARY

Management of these conditions in LMICs requires an integrated pathology solution that will enable early screening, diagnosis and monitoring.

Tenofovir and adefovir down-regulate mitochondrial chaperone TRAP1 and succinate dehydrogenase subunit B to metabolically reprogram glucose metabolism and induce nephrotoxicity

Despite the therapeutic success of tenofovir (TFV) for treatment of HIV-1 infection, numerous cases of nephrotoxicity have been reported. Mitochondrial toxicity has been purported as the major target of TFV-associated renal tubulopathy but the underlying molecular mechanism remains unclear. In this report, we use metabolomics and proteomics with HK-2 cells and animal models to dissect the molecular pathways underlying nephropathy caused by TFV and its more toxic analog, adefovir (ADV). Proteomic analysis shows that mitochondrial chaperone TRAP1 and mtDNA replicating protein SSBP1 were significantly down-regulated in TFV and ADV treated HK-2 cells compared with controls. Transmission electron microscopy (TEM) revealed that TFV and ADV-treated HK-2 cells had accumulated glycogen, a phenotype that was also observed in mice treated with TFV and ADV. Analysis of the proteins in TCA cycle showed succinate dehydrogenase subunit B (SDHB) was nearly depleted in glucose oxidative phosphorylation pathway however certain enzymes in the glycolysis and glycogen synthesis pathway had elevated expression in TFV and ADV-treated HK-2 cells. These results suggest that TFV and ADV may cause mitochondrial dysfunction in renal tubular cells and reprogramming of glucose metabolism. The resulting glycogen accumulation may partially contribute to TFV and ADV induced renal dysfunction.

Infection-Related Focal Segmental Glomerulosclerosis in Children

Focal segmental glomerulosclerosis (FSGS) is the most common cause of steroid resistant nephrotic syndrome in children. It describes a unique histological picture of glomerular damage resulting from several causes. In the majority of patients the causing agent is still unknown, but in some cases viral association is evident. In adults, the most established FSGS causing virus is the human immune-deficiency virus, which is related to a collapsing variant of FSGS. Nevertheless, other viruses are also suspected for causing a collapsing or noncollapsing variant, for example, hepatitis B virus, parvovirus B19, and Cytomegalovirus. Although the systemic infection mechanism is different for these viruses, there are similarities in the pathomechanism for the induction of FSGS. As the podocyte is the key structure in the pathogenesis of FSGS, a direct infection of these cells or immediate damage through the virus or viral components has to be considered. Although viral infections are a very rare cause for FSGS in children, the treating pediatric nephrologist has to be aware of a possible underlying infection, as this has a relevant impact on therapy and prognosis.

Saquinavir Loaded Acetalated Dextran Microconfetti - a Long Acting Protease Inhibitor Injectable

PURPOSE

Since the adoption of highly active antiretroviral therapy, HIV disease progression has slowed across the world; however, patients are often required to take multiple medications daily of poorly bioavailable drugs via the oral route, leading to gastrointestinal irritation. Recently, long acting antiretroviral injectables that deliver drug for months at a time have moved into late phase clinical trials. Unfortunately, these solid phase crystal formulations have inherent drawbacks in potential dose dumping and a greater likelihood for burst release of drug compared to polymeric formulations.

METHODS

Using electrospinning, acetalated dextran scaffolds containing the protease inhibitor saquinavir were created. Grinding techniques were then used to process these scaffolds into injectables which are termed saquinavir microconfetti. Microconfetti was analyzed for in vitro and in vivo release kinetics.

RESULTS

Highly saquinavir loaded acetalated dextran electrospun fibers were able to be formed and processed into saquinavir microconfetti while other polymers such as poly lactic-co-glycolic acid and polycaprolactone were unable to do so. Saquinavir microconfetti release kinetics were able to be tuned via drug loading and polymer degradation rates. In vivo, a single subcutaneous injection of saquinavir microconfetti released drug for greater than a week with large tissue retention.

CONCLUSIONS

Microconfetti is a uniquely tunable long acting injectable that would reduce the formation of adherence related HIV resistance. Our findings suggest that the injectable microconfetti delivery system could be used for long acting controlled release of saquinavir and other hydrophobic small molecule drugs.

Renal abnormalities among HIV infected children at Muhimbili National Hospital (MNH)-Dar es Salaam, Tanzania

Background

Human Immunodeficiency Virus infection is a multisystem disease that contributes to significant morbidity. Renal involvement is reported to be common among patients with HIV. This study was carried out to determine renal involvement using simple bedside tests combined with ultrasonography examination.

Methods

We recruited 240 children from the HIV clinic at Muhimbili National Hospital. Data were collected using structured questionnaires and included demographic, clinical information, radiological tests; renal ultrasound and laboratory tests; serum creatinine, white blood cells, CD4+ counts and percent, urine for microalbuminuria and proteinuria.

Results

Microalbuminuria and proteinuria were present in 20.4 % and 7.1 % respectively. Significantly higher prevalence of microalbuminuria (p < 0.01) and proteinuria p < 0.01) were noted with low CD4 percent (<25 %). Lower mean CD4+ count were noted among children with microalbuminuria [937.4 ± 595.3 cells/μL vs 1164.7 ± 664.3 cell/μL, (p < 0.05)] and proteinuria [675.5 ± 352.3 cells/μL vs 1152 ± 662 cells/μL (p < 0.001)]. Fourteen (5.8 %) HIV infected children had estimated glomerular filtration rate (eGFR of 30–59) consistent with severe renal impairment. Increased cortical echogenicity was noted in 69/153 (39.2 %) of participants who had ultrasound examination.

Conclusion

Microalbuminuria, proteinuria and renal dysfunction were noted to be prevalent among HIV infected children indicating the need to consider routine screening of renal complications in these children.

Epidemiology, clinical characteristics, and management of chronic kidney disease in human immunodeficiency virus-infected patients

Antiretroviral therapy has markedly reduced acquired immune deficiency syndrome-related deaths and opportunistic infectious diseases. This has resulted in prolonged survival of individuals infected with the human immunodeficiency virus (HIV). However, this improvement in survival has been accompanied by an increase in the incidence of chronic kidney disease (CKD) and end-stage renal disease. CKD is now epidemic among HIV-infected populations in both Western and Eastern countries. Risk factors associated with CKD in HIV-infected populations include aging, hypertension, diabetes mellitus, co-infection with hepatitis C virus, a low CD4 cell count, and a high HIV viral load. Clinical experience has shown that HIV-infected individuals often have one or more concurrent risk factors for CKD. The cumulative effect of multiple risk factors on the development of CKD should be noted in this population. Glomerular disease directly related to HIV infection, so-called HIV-associated nephropathy, remains an important cause of CKD among a limited HIV population of African descent, but is less likely to be common among other urban HIV populations. The impact of exposure to nephrotoxic antiretroviral agents on the development of kidney disease is both an old and a new concern. In particular, the association of tenofovir with kidney tubular injury has been an area of great interest. The findings regarding tenofovir's adverse effect on long-term kidney function vary among studies. The early identification and treatment of CKD is recommended for reducing the burden of patients requiring dialysis in HIV-infected populations. Periodic monitoring of urinary concentrations of albumin, protein, and tubular injury markers such as low-molecular-weight proteins may be useful for the early diagnosis of patients at risk for incident CKD. This review focuses on recent epidemiology, clinical characteristics, and management of CKD in a contemporary HIV-infected population.

The new face of the pediatric HIV epidemic in Western countries: demographic characteristics, morbidity and mortality of the pediatric HIV-infected population

The natural history of the pediatric HIV epidemic has changed since the introduction of strategies for the prevention of mother-to-child transmission and the implementation of highly active antiretroviral therapy. The demographic characteristics of the pediatric HIV-infected population and the incidence and pattern of HIV-related morbidity, as well as mortality rates, have been remarkably modified. This report gives an overview on the main changes that occurred in Western countries.

Expression of drug transporters in human kidney: impact of sex, age, and ethnicity

Background

Differences in expression of drug transporters in human kidney contribute to changes in pharmacokinetics and toxicokinetics of a variety of drug compounds. The basal expression levels of genes involved in drug transport processes in the kidney introduces differences in bioavailability, distribution, and clearance of drugs, possibly influencing drug efficacy and adverse reactions. Sex differences in gene expression of transporters are a key cause of differences in sex-dependent pharmacokinetics, which may characterize many drugs and contribute to individual differences in drug efficacy and toxicity. Therefore, evaluating the expression of drug transporters in normal human kidneys is important to better understand differences in drug bioavailability, distribution, and clearance of drugs in humans. Other factors such as age and ethnicity may also contribute to individual differences in gene expression of drug transporters in the human kidney.

Methods

Quantitative real-time PCR (QRT-PCR) was performed to determine the gene expression of 30 drug transporters in 95 age-matched normal human kidney tissues. Multiple Student’s t-tests (Sidak-Bonferroni correction) and two-way ANOVA (Bonferroni correction) analyses were used to determine statistically significant differences.

Results

In the 30 transporter genes examined, sex, ethnicity, and age differences in gene expression were exhibited in normal human kidney tissue. These changes in expression were not found to be differentially significant. However, sex-age and sex-ethnicity interactions were found to be statistically significant. For sex-age interactions, SCL22A12 was found to be significantly higher expressed in females <50 years compared to males <50 years. Expression levels of SLC22A2, SLC22A12, SLC6A16, and ABCB6 were significantly higher in females <50 years compared to females ≥50 years. In sex-ethnicity interactions, expression levels of ATP7B and KCNJ8 were found to be significantly higher in African American females compared to European American females. Also, the expression of SLC31A2 was significantly higher in European American males compared to European American females.

Conclusions

Sex, age, and ethnic differences impacted the expression of drug transporters in normal human kidneys, which suggests that the analysis of gene expression of drug transporters will aid in improving the usage/dosage of drug therapies influencing personalized medicine and susceptibility to adverse drug reactions.

In vivo assessment of antiretroviral therapy-associated side effects

Antiretroviral therapy has been associated with side effects, either from the drug itself or in conjunction with the effects of human immunodeficiency virus infection. Here, we evaluated the side effects of the protease inhibitor (PI) indinavir in hamsters consuming a normal or high-fat diet. Indinavir treatment increased the hamster death rate and resulted in an increase in triglyceride, cholesterol and glucose serum levels and a reduction in anti-oxLDL auto-antibodies. The treatment led to histopathological alterations of the kidney and the heart. These results suggest that hamsters are an interesting model for the study of the side effects of antiretroviral drugs, such as PIs.

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

OBJECTIVE

In this study, data regarding epidemiology, risk factors, pathogenesis and outcome of tenofovir-induced nephrotoxicity will be reviewed, and current and future approaches for prevention will be discussed.

METHOD

The data were collected by searching Scopus, PubMed, Medline, Science direct, Clinical trials and Cochrane database systematic reviews. The keywords used as search terms were "Tenofovir", "TDF", "NRTI", "Nephrotoxicity", "Renal failure", "Kidney damage", "HIV" and "AIDS".

RESULTS AND CONCLUSION

Several predisposing factors including elevated baseline SCr, concomitant nephrotoxic medications, low body weight, advanced age, tenofovir disoproxil fumarate (TDF) dose and duration of treatment and lower CD4 cell count were identified as risk factors for development of TDF-induced nephrotoxicity. Cellular accumulation through increased entry from the human organic anion transporters and decreased efflux into tubular lumen is main mechanism of nucleotide analogue antiviral induced nephrotoxicity. Renal function assessment and monitoring at baseline and during TDF treatment are the main approach of prevention of TDF-induced nephrotoxicity. Rosiglitazone may be helpful in patients presenting with TDF-induced nephrotoxicity. Pretreatment with melatonin prevented all known histological changes in proximal tubular mitochondira induced by TDF. Use of antioxidants with mitochondria-targeted properties such as MitoQ or Mito-CP may prevent proximal tubular mitochondrial against TDF damage. Vitamin E, ebselen, lipoic acid, plastoquinone, nitroxides, SOD enzyme mimetics, Szeto-Schiller (SS) peptides, and quercetin are other potential agents for prevention of TDF-induced nephrotoxicity. However, data regarding effectiveness of nephroprotective agents against TDF-induced nephrotoxicity are not conclusive. Before extrapolation of the preclinical evidence to clinical practice, these evidence should be confirmed in future human studies.

Urine liver-type fatty acid-binding protein and kidney injury molecule-1 in HIV-infected patients receiving combined antiretroviral treatment based on tenofovir

The aim of this study was to determine the presence of kidney tubular damage in the absence of overt evidence of glomerular dysfunction (GFR>60 ml/min without proteinuria) in HIV-infected patients receiving antiretroviral therapy. Urine kidney injury molecule-1 (KIM-1) and liver-type fatty acid-binding protein (L-FABP) levels were measured by ELISA and expressed as a ratio to creatinine. Sixty-six patients (median age 38 years) and 10 healthy controls (median age 35.5 years) were included in the study. Patients with chronic diseases such as diabetes, hypertension, heart disease, or kidney disease were excluded from the study. All patients received tenofovir/emtricitabine combined with one of three other components, namely efavirenz, atazanavir/norvir, or lopinavir/norvir. A lower concentration of L-FABP/creatinine was observed in HIV-infected as compared to healthy individuals (p=0.0353); KIM-1/creatinine was also lower in comparison with healthy controls but not statistically significantly. Patients receiving efavirenz had higher levels of L-FABP/creatinine in comparison to healthy controls (p=0.0039). Patients with anti-HCV had higher concentrations of L-FABP/creatinine as compared to the HIV-monoinfected individuals (not statistically significant) and to healthy subjects (p=0.0356). All four patients with L-FABP>17.5 μg/g creatinine were HIV/HCV coinfected. On multivariate logistic regression urine L-FABP above 5.5 μg/g creatinine was independently associated with body weight (OR=0.93 p=0.039). This study suggests that HIV/HCV-coinfected patients with lower body weight treated with tenofovir may be at an increased risk of tubular dysfunction and should be monitored more closely. The use of protease inhibitors was not associated with an increased risk of tubular disorders.

Kidney disease in children and adolescents with perinatal HIV-1 infection

Introduction

Involvement of the kidney in children and adolescents with perinatal (HIV-1) infection can occur at any stage during the child's life with diverse diagnoses, ranging from acute kidney injury, childhood urinary tract infections (UTIs), electrolyte imbalances and drug-induced nephrotoxicity, to diseases of the glomerulus. The latter include various immune-mediated chronic kidney diseases (CKD) and HIV-associated nephropathy (HIVAN).

Discussion

The introduction of highly active anti-retroviral therapy (HAART) has dramatically reduced the incidence of HIVAN, once the commonest form of CKD in children of African descent living with HIV, and also altered its prognosis from eventual progression to end-stage kidney disease to one that is compatible with long-term survival. The impact of HAART on the outcome of other forms of kidney diseases seen in this population has not been as impressive. Increasingly important is nephrotoxicity secondary to the prolonged use of anti-retroviral agents, and the occurrence of co-morbid kidney disease unrelated to HIV infection or its treatment. Improved understanding of the molecular pathogenesis and genetics of kidney diseases associated with HIV will result in better screening, prevention and treatment efforts, as HIV specialists and nephrologists coordinate clinical care of these patients. Both haemodialysis (HD) and peritoneal dialysis (PD) are effective as renal replacement therapy in HIV-infected patients with end-stage kidney disease, with PD being preferred in resource-limited settings. Kidney transplantation, once contraindicated in this population, has now become the most effective renal replacement therapy, provided rigorous criteria are met. Given the attendant morbidity and mortality in HIV-infected children and adolescents with kidney disease, routine screening for kidney disease is recommended where resources permit.

Conclusions

This review focuses on the pathogenesis and genetics, clinical presentation and management of kidney disease in children and adolescents with perinatal HIV-1 infection.

Inhibition of Notch pathway attenuates the progression of human immunodeficiency virus-associated nephropathy

The Notch pathway is an evolutionarily conserved signaling cascade that is critical in kidney development and has also been shown to play a pathogenetic role in a variety of kidney diseases. We have previously shown that the Notch signaling pathway is activated in human immunodeficiency virus-associated nephropathy (HIVAN) as well as in a rat model of the disease. In this study, we examined Notch signaling in the well established Tg26 mouse model of HIVAN. Notch signaling components were distinctly upregulated in the kidneys of these mice as well as in immortalized podocytes derived from these mice. Notch1 and Notch4 were upregulated in the Tg26 glomeruli, and Notch4 was also expressed in tubules. Notch ligands Jagged1, Jagged2, Delta-like1, and Delta-like 4 were all upregulated in the tubules of Tg26 mice, but glomeruli showed minimal expression of Notch ligands. To examine a potential pathogenetic role for Notch in HIVAN, Tg26 mice were treated with GSIXX, a gamma secretase inhibitor that blocks Notch signaling. Strikingly, GSIXX treatment resulted in significant improvement in both histological kidney injury scores and renal function. GSIXX-treated Tg26 mice also showed diminished podocyte proliferation and dedifferentiation, cellular hallmarks of the disease. Moreover, GSIXX blocked podocyte proliferation in vitro induced by HIV proteins Nef and Tat. These studies suggest that Notch signaling can promote HIVAN progression and that Notch inhibition may be a viable treatment strategy for HIVAN.

Prevalence of proteinuria and elevated serum cystatin C among HIV-Infected Adolescents in the Reaching for Excellence in Adolescent Care and Health (REACH) study

OBJECTIVE

In the United States, kidney dysfunction is prevalent in almost 30% of HIV-infected patients and is an independent predictor of mortality. Proteinuria and elevated serum cystatin C (eCysC) are used as markers of kidney disease in the general population; however, the prevalence of these markers in HIV-infected adolescents is largely unknown.

METHODS

This study includes 304 HIV-infected adolescents from the Reaching for Excellence in Adolescent Care and Health (REACH) cohort, an observational study of adolescents recruited from 13 US cities. Clinical and demographic characteristics of participants were evaluated as correlates of proteinuria, a urine protein to creatinine ratio of ≥200 mg/g. Select univariate predictors were assessed to determine the association with urinary protein excretion and serum cystatin C in multivariable linear regression models and proteinuria and eCysC (eCysC ≥ 75th percentile) in multivariable logistic regression models.

RESULTS

Overall, 19.1% of the participants had proteinuria, whereas 23.7% had an eCysC. Low CD4 T-lymphocyte counts (<200 cells/mm) were significantly associated with a greater urine protein to creatinine ratio in linear models and with proteinuria in logistic regression models. CD4 T-lymphocyte counts <500 cells/mm were significantly associated with a greater serum cystatin C concentration in linear models and with eCysC in logistic regression models.

CONCLUSIONS

Proteinuria among HIV-infected adolescents in the REACH cohort was approximately 2-fold greater than healthy US adolescents. Both proteinuria and eCysC are associated with CD4 T-lymphocyte counts. Further studies investigating early markers of kidney disease and the association with immune status and inflammation in HIV-infected adolescents are needed.

Examination of haematotoxicity of fixed-dose highly active antiretroviral drug in albino wistar rats

Highly active antiretroviral therapy (HAART) is considered toxic and has other life-threatening side effects. Our aim was to evaluate the haematotoxic effects of lamivudine, zidovudine, and nevirapine fixed-dose combinations in Albino Wistar rats. Fifty (50) three (3) months old male Albino Wistar rats weighing between 200 and 250 g were randomly assigned to five (5) groups (A, B, C, D, and E). Group A served as control. Two (2 mLs) of venous blood was aseptically collected on Days 5, 10, 15, 20, and 25 of treatment. Red blood cell (RBC) mean value recorded statistically significant increase (P < 0.05) in groups B and C when compared with the control group on Day 5. However, there was a statistically significant decrease (P < 0.05) in RBC, haemoglobin concentration (Hb), packed cell volume (PCV), and some red cell indices on Day 10. In addition there was no statistically significant difference (P > 0.05) in all the parameters evaluated when the test group was compared with the control on Day 25. Furthermore, there was a time-related statistically significant increase (P < 0.05) in the two major blood cells—RBC and platelet counts. From the result of this present study, it can be concluded that HAART when administered in fixed-dose combinations have no subacute haematotoxic effects.

Performance of creatinine and cystatin C GFR estimating equations in an HIV-positive population on antiretrovirals

OBJECTIVE

To evaluate the performance of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine, cystatin C, and creatinine-cystatin C estimating equations in HIV-positive patients.

METHODS

We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) Study and CKD-EPI creatinine 2009, CKD-EPI cystatin C 2012, and CKD-EPI creatinine-cystatin C 2012 glomerular filtration rate (GFR) estimating equations compared with GFR measured using plasma clearance of iohexol in 200 HIV-positive patients on stable antiretroviral therapy. Creatinine and cystatin C assays were standardized to certified reference materials.

RESULTS

Of the 200 participants, median (IQR) CD4 count was 536 (421) and 61% had an undetectable HIV viral load. Mean (SD) measured GFR (mGFR) was 87 (26) mL/min per 1.73 m. All CKD-EPI equations performed better than the MDRD Study equation. All 3 CKD-EPI equations had similar bias and precision. The cystatin C equation was not more accurate than the creatinine equation. The creatinine-cystatin C equation was significantly more accurate than the cystatin C equation, and there was a trend toward greater accuracy than the creatinine equation. Accuracy was equal or better in most subgroups with the combined equation compared to either alone.

CONCLUSIONS

The CKD-EPI cystatin C equation does not seem to be more accurate than the CKD-EPI creatinine equation in patients who are HIV-positive, supporting the use of the CKD-EPI creatinine equation for routine clinical care for use in North American populations with HIV. The use of both filtration markers together as a confirmatory test for decreased estimated GFR based on creatinine in individuals who are HIV-positive requires further study.

How to manage HIV-infected patients with chronic kidney disease in the HAART era

As human immunodeficiency virus (HIV)-infected patients now live longer while receiving highly active antiretroviral therapy (HAART), chronic kidney disease (CKD) has emerged as a significant cause of morbidity and mortality among urban HIV population. Risk factors associated with CKD in such HIV-infected population include aging, hypertension, diabetes mellitus, co-infection with hepatitis C virus, low CD4 cell count, and high HIV viral load. Clinical experience has shown that HIV-infected individuals often have one or more concurrent risk factors for CKD. The cumulative effect of multiple risk factors on the development of CKD should be noted in this population. Glomerular disease directly related to HIV infection, so-called HIV-associated nephropathy, remains an important cause of CKD among limited HIV population of African descent. The impact of exposure to nephrotoxic antiretroviral agents on the development of kidney disease is both an old and a new concern. In particular, the association of tenofovir with kidney disease has been an area of great interest. The findings regarding tenofovir's adverse effect on long-term kidney function vary among studies. Early identification and treatment of kidney disease is imperative for reducing the burden of patients requiring dialysis in HIV-infected populations. Periodic monitoring of urinary albumin excretion, tubular parameters such as low-molecular-weight proteinuria, and the estimated glomerular filtration rate may be useful for early diagnosis of patients at risk for incident CKD. This review focuses on recent developments in epidemiology, risk factors, identification, estimation, and management of CKD in HIV-infected population in the HAART era.

Renal toxicity associated with antiretroviral therapy

Renal disease is becoming an increasingly prevalent comorbidity in patients with human immunodeficiency virus (HIV) infection. The increase in life expectancy following the introduction of highly active antiretroviral therapy (HAART) and the long-term development of metabolic complications (such as diabetes and dyslipidaemia), hypertension, and vascular diseases can contribute to the increasing frequency in the recognition of renal impairment in HIV-infected patients. Some antiretroviral agents, and particularly tenofovir, have been associated with nephrotoxic drug effects, including decline in glomerular filtration rate, proximal tubular damage, and acute kidney injury. The occurrence of clinically evident renal toxicity in patients treated with HAART seems to be very low, but glomerular or tubular subclinical dysfunction may occur more frequently. Therefore, careful clinical and laboratory monitoring for the early recognition of renal abnormalities is recommended for all subjects receiving antiretroviral treatment. In this article, the current knowledge about the nephrotoxic effects of antiretroviral agents has been reviewed, and an algorithm for screening and management of HAART-related kidney disease is proposed in the light of the most recent clinical studies and international guidelines.

The spectrum of HIV-related nephropathy in children

BACKGROUND

Despite the burden of human immunodeficiency virus (HIV) disease in Southern Africa, there have been few reports of HIV-related nephropathy in children. This study outlines the spectrum of HIV-1-related kidney diseases of children in KwaZulu-Natal, South Africa.

METHODS

A review of the clinical presentation, laboratory and histopathological findings of children diagnosed with HIV-related nephropathy.

RESULTS

Forty-nine out of 71 children (1-16 years old) with HIV-1 related nephropathy underwent kidney biopsy. The most common histopathological finding was focal segmental glomerulosclerosis (FSGS), which was present in 32 (65.3%) children; 13 (26.5%) having collapsing glomerulopathy and 19 (38.8%) classic FSGS. The majority of patients showed haematological (86.4%) and electrolyte abnormalities (69.4%). Renal impairment was present in 41% of patients on initial presentation. However, end-stage kidney disease was present in only 4% of these patients. All patients were treated with highly active anti-retroviral therapy (HAART), the majority (79.6%) showed decreased proteinuria with 38.8% having complete remission.

CONCLUSIONS

This study, one of the largest series of children reported from Africa, demonstrates that nephrotic syndrome due to HIV-associated nephropathy (HIVAN) is the commonest presentation of HIV-related nephropathy in childhood. Highly active anti-retroviral therapy in combination with angiotensin-converting enzyme antagonists is highly effective in decreasing proteinuria and preserving renal function.

A randomized, pilot trial to evaluate glomerular filtration rate by creatinine or cystatin C in naive HIV-infected patients after tenofovir/emtricitabine in combination with atazanavir/ritonavir or efavirenz

BACKGROUND

Glomerular filtration rate (GFR) estimated by Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on creatinine or cystatine C may be more accurate methods especially in patients without chronic kidney disease. There is lack of data on GFR estimated by these methods in patients on highly active antiretroviral therapy.

METHODS

Antiretroviral-naive HIV-infected patients were randomized to tenofovir/emtricitabine in association with atazanavir/ritonavir (ATV/r) or efavirenz (EFV) Patients had to have an actual creatinine clearance >50 mL/minute (24-hour urine collection) and were followed for 48 weeks.

RESULTS

Ninety-one patients (48 ATV/r, 43 EFV) were recruited. Using the CKD-EPI creatinine formula, there was a significant decrease in GFR up to week 48 in patients receiving ATV/r (4.9 mL/minute/m(2), P = 0.02) compared with a not statistically significant increment in patients prescribed EFV. Using the cystatin C-based equation, we found greater decrease in GFR in both arms, although, in the EFV arm, the decrease was not statistically significant (5.8 mL/minute/m(2), P = 0.92). At multivariable analysis, ATV/r was a significant predictor of greater decrease in estimated glomerular filtration rate (eGFR) (P = 0.0046) only with CKD-EPI creatinine.

CONCLUSIONS

ATV/r plus tenofovir caused greater GFR decreases compared with EFV. The evaluation of eGFR by cystatin C confirmed this result, but this method seemed to be more stringent, probably precluding the possibility to detect a significant difference in the pattern of eGFR evolution between the two arms over time. More studies are needed to understand the clinical relevance of these alterations and whether cystatin C is a more appropriate method for monitoring GFR in clinical practice.

Diffuse tubulointerstitial nephritis accompanied by renal crystal formation in an HIV-infected patient undergoing highly active antiretroviral therapy

This report presents a human immunodeficiency virus (HIV) patient that developed a slowly progressive renal impairment over years under highly active antiretroviral therapy (HAART). The renal biopsy showed diffuse tubulointerstitial nephritis accompanied by crystal formations that were surrounded by multinuclear giant cells. Furthermore, rod-like crystals were detected in the urinary sediments. Tenofovir and Atazanavir were thought to be the causative drugs for the renal injury. Therefore, the possibility of HARRT-induced nephrotoxicity should be considered in HIV-infected patients, even though the activity of HIV is controlled by such therapies.

Tenofovir renal proximal tubular toxicity is regulated by OAT1 and MRP4 transporters

Tenofovir disoproxil fumarate (TDF) is an oral prodrug and acyclic nucleotide analog of adenosine monophosphate that inhibits HIV-1 (HIV) reverse transcriptase. A growing subset of TDF-treated HIV(+) individuals presented with acute renal failure, suggesting tenofovir-associated kidney-specific toxicity. Our previous studies using an HIV transgenic mouse model (TG) demonstrated specific changes in renal proximal tubular mitochondrial DNA (mtDNA) abundance. Nucleosides are regulated in biological systems via transport and metabolism in cellular compartments. In this study, the role(s) of organic anion transporter type 1 (OAT1) and multidrug-resistant protein type 4 (MRP4) in transport and regulation of tenofovir in proximal tubules were assessed. Renal toxicity was assessed in kidney tissues from OAT1 knockout (KO) or MRP4 KO compared with wild-type (WT, C57BL/6) mice following treatment with TDF (0.11 mg/day), didanosine (ddI, a related adenosine analog, 0.14 mg/day) or vehicle (0.1 M NaOH) daily gavage for 5 weeks. Laser-capture microdissection (LCM) was used to isolate renal proximal tubules for molecular analyses. mtDNA abundance and ultrastructural pathology were analyzed. mtDNA abundance in whole kidneys from both KO and WT was unchanged regardless of treatment. Renal proximal tubular mtDNA abundance from OAT1 KO also remained unchanged, suggesting prevention of TDF toxicity due to loss of tenofovir transport into proximal tubules. In contrast, renal proximal tubules from MRP4 KO exhibited increased mtDNA abundance following TDF treatment compared with WT littermates, suggesting compensation. Renal proximal tubules from TDF-treated WT and MRP4 KO exhibited increased numbers of irregular mitochondria with sparse, fragmented cristae compared with OAT1 KO. Treatment with ddI had a compensatory effect on mtDNA abundance in OAT1 KO but not in MRP4 KO. Both OAT1 and MRP4 have a direct role in transport and efflux of tenofovir, regulating levels of tenofovir in proximal tubules. Disruption of OAT1 activity prevents tenofovir toxicity but loss of MRP4 can lead to increased renal proximal tubular toxicity. These data help to explain mechanisms of human TDF renal toxicity.

Kidney tubular damage in the absence of glomerular defects in HIV-infected patients on highly active antiretroviral therapy

BACKGROUND

The emergence of kidney disease as an important comorbidity among human immunodeficiency virus (HIV)-infected patients receiving highly active antiretroviral therapy (HAART) has emphasized the critical importance of early identification of patients at risk for kidney disease. Use of urine as a diagnostic medium may allow the noninvasive detection of incipient nephropathy in these patients.

METHODS

Here, we conducted cross-sectional and 1-year prospective studies of 424 HIV-infected patients on HAART without proteinuria or significant impairment of glomerular function. N-acetyl-β-D-glucosaminidase, γ-glutamyl transpeptidase, β(2)-microglobulin and α(1)-microglobulin were measured as indices of tubular damage, which was diagnosed when urinary concentrations of at least three tubular biomarkers exceeded the reference range. Risk factors associated with tubular damage were examined using multivariate logistic regression analysis.

RESULTS

Tubular damage was identified in 107 patients (25%), who were characterized by advanced age [odds ratio (OR), 1.04; 95% confidence interval (CI), 1.01-1.07], high C-reactive protein (OR, 1.96; 95% CI, 1.26-3.14) and coexisting diabetes mellitus (OR, 3.97; 95% CI, 1.44-12.2). The use of tenofovir, the most likely tubulotoxic agent, was not statistically involved in this subclinical tubular damage. The 1-year follow-up study showed that a decrease in estimated glomerular filtration rate (eGFR) and incidence of proteinuria during the period were significantly higher in patients with than without tubular damage.

CONCLUSIONS

A quarter of HIV-infected patients receiving HAART had subclinical tubular damage, which was associated with a near-term decline in eGFR and higher incidence of proteinuria. Periodic monitoring of urinary biomarkers might facilitate the early identification of HAART patients predisposed to significant kidney disease.

A simple model for predicting incidence of chronic kidney disease in HIV-infected patients

BACKGROUND

Human immunodeficiency virus (HIV)-infected individuals have concurrent risk factors for chronic kidney disease (CKD), but there are no prediction models to quantify the effect of multiple factors on the development of incident CKD.

METHODS

A 1-year prognostic model was developed using prospective data between January 2008 and March 2009, from a derivation cohort of 623 patients with an estimated glomerular filtration rate (eGFR) exceeding 60 ml/min/1.73 m(2) at baseline. Incident CKD was defined as both an eGFR falling below 60 ml/min/1.73 m(2) and a decrease in eGFR of at least 25% during the period. Continuous variables were divided into categories using the mean value of the whole cohort. Multivariate logistic regression was used to determine baseline categories associated with incident CKD. The model was tested with prospective data between April 2009 and March 2010, from a validation cohort of 534 patients exceeding 60 ml/min/1.73 m(2) at baseline, consisting of part of the derivation cohort and newly enrolled patients. The discriminative ability was evaluated using the area under the receiver operating characteristic (AROC) curve.

RESULTS

Eighteen subjects developed incident CKD (2.9%). In a multivariate logistic regression analysis of the derivation cohort, 5 variables (age, CD4 cell count, diabetes, proteinuria, and eGFR at baseline) were independently associated with the incidence of CKD. The AROC curve was 0.841 (95% CI 0.799-0.894) in the validation cohort.

CONCLUSION

This prediction model may be a useful tool for identifying HIV-infected individuals with a high likelihood of new-onset CKD.

Renal transplantation in HIV-infected patients: 2010 update

The prognosis of human immunodeficiency virus (HIV) infection has improved in recent years with the introduction of antiretroviral treatment. While the frequency of AIDS-defining events has decreased as a cause of death, mortality from non-AIDS-related events including end-stage renal diseases has increased. The etiology of chronic kidney disease is multifactorial: immune-mediated glomerulonephritis, HIV-associated nephropathy, thrombotic microangiopathies, and so on. HIV infection is no longer a contraindication to transplantation and is becoming standard therapy in most developed countries. The HIV criteria used to select patients for renal transplantation are similar in Europe and North America. Current criteria state that prior opportunistic infections are not a strict exclusion criterion, but patients must have a CD4+ count above 200 cells/mm(3) and a HIV-1 RNA viral load suppressible with treatment. In recent years, more than 200 renal transplants have been performed in HIV-infected patients worldwide, and mid-term patient and graft survival rates have been similar to that of HIV-negative patients. The main issues in post-transplant period are pharmacokinetic interactions between antiretrovirals and immunosuppressants, a high rate of acute rejection, the management of hepatitis C virus coinfection, and the high cardiovascular risk after transplantation. More studies are needed to determine the most appropriate antiretroviral and immunosuppressive regimens and the long-term outcome of HIV infection and kidney graft.

Hypomagnesemia is a risk factor for nonrecovery of renal function and mortality in AIDS patients with acute kidney injury

The objective of the present study was to determine the prevalence of electrolyte disturbances in AIDS patients developing acute kidney injury in the hospital setting, as well as to determine whether such disturbances constitute a risk factor for nephrotoxic and ischemic injury. A prospective, observational cohort study was carried out. Hospitalized AIDS patients were evaluated for age; gender; coinfection with hepatitis; diabetes mellitus; hypertension; time since HIV seroconversion; CD4 count; HIV viral load; proteinuria; serum levels of creatinine, urea, sodium, potassium and magnesium; antiretroviral use; nephrotoxic drug use; sepsis; intensive care unit (ICU) admission, and the need for dialysis. Each of these characteristics was correlated with the development of acute kidney injury, with recovery of renal function and with survival. Fifty-four patients developed acute kidney injury: 72% were males, 59% had been HIV-infected for >5 years, 72% had CD4 counts <200 cells/mm(3), 87% developed electrolyte disturbances, 33% recovered renal function, and 56% survived. ICU admission, dialysis, sepsis and hypomagnesemia were all significantly associated with nonrecovery of renal function and with mortality. Nonrecovery of renal function was significantly associated with hypomagnesemia, as was mortality in the multivariate analysis. The risks for nonrecovery of renal function and for death were 6.94 and 6.92 times greater, respectively, for patients with hypomagnesemia. In hospitalized AIDS patients, hypomagnesemia is a risk factor for nonrecovery of renal function and for in-hospital mortality. To determine whether hypomagnesemia is a determinant or simply a marker of critical illness, further studies involving magnesium supplementation in AIDS patients are warranted.

Trends in Diseases Reported on US Death Certificates That Mentioned HIV Infection, 1996-2006

OBJECTIVE

We examined trends during 1996-2006 in diseases reported on death certificates that mentioned HIV infection.

METHODS

We analyzed multiple-cause mortality data compiled from all US death certificates with any mention of HIV to determine the annual percentages of deaths with various diseases.

RESULTS

Deaths reported with HIV during 1996-2006 decreased from 35 340 to 13 750. Standardized percentages of death certificates reporting AIDS-defining opportunistic infections also decreased: pneumocytosis (6.3% to 5.1%), nontuberculous mycobacteriosis (5.5% to 1.8%), cytomegalovirus (5.7% to 1.2%). Non-Hodgkin's lymphoma rose from 4.8% in 1996 to 6.4% in 1997 and declined to 5.0% in 2001, while Kaposi's sarcoma declined from 3.7% in 1996 to 1.7% in 2001; these AIDS-defining cancers had stable percentages after 2001. All other cancers increased during 1996-2006 (2.7% to 7.3%). The percentage of deaths with diseases not specifically attributable to HIV increased: liver disease (5.8% to 13.0%), kidney disease (7.9% to 12.0%), and heart disease (4.9% to 10.2%).

CONCLUSION

Among deaths reported with HIV, the percentages reported with HIV-attributable diseases decreased, while the percentages reported with other diseases increased. Consequently, these other life-threatening diseases need more attention in the management of HIV-infected persons.

Mitochondrial changes in cidofovir therapy for BK virus nephropathy

Polyoma (BK) virus nephropathy (BKVN) is often treated with the nucleotide analog cidofovir. An adverse effect of this drug class is proximal tubular toxicity, and ultrastructural abnormalities in proximal tubular mitochondria have been observed in patients treated with similar drugs for other viral infections. We report similar changes in biopsies from BKVN treated with cidofovir. Renal allograft biopsies showing BKVN, on which electron microscopy was performed, were categorized into 3 groups: initial diagnosis (BD), postcidofovir treatment (CT), and posttreatment with immunosuppression reduction (IR). Nineteen cases from each group were randomly selected. Mitochondrial changes were present in 6 biopsies from patients receiving CT therapy (31.5%), ranging from diffuse mitochondrial swelling to profound morphologic changes. No similar abnormalities were seen in other groups. In those with atypical mitochondria, the mean number of cidofovir doses was 2.67, with an average interval between last dose and biopsy of 2.17 weeks. CT patients without mitochondrial changes had a mean of 4.6 doses and an average interval between last dose and biopsy of 27.2 weeks. Some renal transplant patients treated with cidofovir display alterations in proximal tubular mitochondria akin to those seen with similar drugs. The findings support the mitochondrial toxicity of nucleotide analogs.

Noninfectious HIV-related comorbidities and HAART toxicities: choosing alternative antiretroviral strategies

In the HAART era, clinicians are faced with the challenge of treating an aging HIV-infected population increasingly affected by severe comorbidities, which may compromise the tolerability of antiretroviral regimens. In this special population, it is imperative for physicians to carefully tailor antiretroviral treatment in order not to worsen patients’ underlying clinical conditions and to achieve both tolerability and immune–virologic efficacy. This article aims to explore the impact of standard HAART regimens on the different noninfectious HIV-related comorbidities: metabolic, cardiovascular, bone and renal diseases, in order to provide tools to fit the most appropriate antiretroviral combination according to individual clinical conditions. Clinical experience with alternative antiretroviral strategies, avoiding nucleoside reverse transcriptase inhibitor toxicities and involving new antiretroviral classes, will be reviewed to obtain an overview on future perspectives.

Estimated glomerular filtration rate, chronic kidney disease and antiretroviral drug use in HIV-positive patients

OBJECTIVES

Chronic kidney disease (CKD) in HIV-positive persons might be caused by both HIV and traditional or non-HIV-related factors. Our objective was to investigate long-term exposure to specific antiretroviral drugs and CKD.

DESIGN

A cohort study including 6843 HIV-positive persons with at least three serum creatinine measurements and corresponding body weight measurements from 2004 onwards.

METHODS

CKD was defined as either confirmed (two measurements >or=3 months apart) estimated glomerular filtration rate (eGFR) of 60 ml/min per 1.73 m or below for persons with baseline eGFR of above 60 ml/min per 1.73 m or confirmed 25% decline in eGFR for persons with baseline eGFR of 60 ml/min per 1.73 m or less, using the Cockcroft-Gault formula. Poisson regression was used to determine factors associated with CKD.

RESULTS

Two hundred and twenty-five (3.3%) persons progressed to CKD during 21 482 person-years follow-up, an incidence of 1.05 per 100 person-years follow-up [95% confidence interval (CI) 0.91-1.18]; median follow-up was 3.7 years (interquartile range 2.8-5.7). After adjustment for traditional factors associated with CKD and other confounding variables, increasing cumulative exposure to tenofovir [incidence rate ratio (IRR) per year 1.16, 95% CI 1.06-1.25, P < 0.0001), indinavir (IRR 1.12, 95% CI 1.06-1.18, P < 0.0001), atazanavir (IRR 1.21, 95% CI 1.09-1.34, P = 0.0003) and lopinavir/r (IRR 1.08, 95% CI 1.01-1.16, P = 0.030) were associated with a significantly increased rate of CKD. Consistent results were observed in wide-ranging sensitivity analyses, although of marginal statistical significance for lopinavir/r. No other antiretroviral drugs were associated with increased incidence of CKD.

CONCLUSION

In this nonrandomized large cohort, increasing exposure to tenofovir was associated with a higher incidence of CKD, as was true for indinavir and atazanavir, whereas the results for lopinavir/r were less clear.

CKD in HIV-infected patients other than HIV-associated nephropathy

A spectrum of kidney diseases in HIV-infected patients has been reported both before and after the introduction of highly active antiretroviral therapy (HAART). Kidney syndromes affecting HIV-infected patients include CKD as well as proteinuria, nephrotic syndrome, and acute nephritic syndrome. Thrombotic microangiopathy should be considered in patients with kidney disease and typical clinical characteristics. As the HIV-infected population ages, there is increased concern regarding the incidence of vascular and metabolic disease, leading to an increased burden of CKD. Although HIV-associated nephropathy is still the major cause of nephrotic syndrome in HIV-infected patients, immune complex glomerulonephritis (ICGN) still comprises a substantial proportion of the disease burden, especially in people of European origin. Genetic investigations into the underpinnings of the various histologic expressions of HIV-associated kidney disease hold great promise. The single most important diagnostic test to differentiate various forms of kidney disease in HIV-infected patients is a kidney biopsy. The results of treating kidney disease in HIV-infected patients remain unclear, and properly designed randomized controlled trials of the treatment of ICGN with HAART and other approaches are desperately needed.

Renal consequences of HIV and HIV therapy

PURPOSE OF REVIEW

To highlight the latest data documenting new concerns about renal function in HIV-infected patients, with regard to acute renal failure with its known burden of mortality and prolonged hospitalization, antiretroviral medication errors potentially enhancing the risk of the emergence of viral resistance, outcome of HIV dialysis patients, and renal involvement in the immune restoration inflammatory syndrome.

RECENT FINDINGS

The incidence of acute renal failure in HIV-infected patients is increasing, secondary to ageing, chronic kidney disease and liver disease. Histological documentation is critical for the best diagnosis. Antiretroviral medication errors are very frequently encountered in HIV-infected patients, which may be associated with decreased survival as a result of the under/over-prescription of highly active antiretroviral therapy in chronic kidney disease or end-stage renal disease.

SUMMARY

Evaluating the glomerular filtration rate with plasma creatinine and one of the validated formulae is critical in HIV-infected patients to determine the optimum follow-up strategy and critical therapeutic measures, such as drug dosage adaptation. High-risk radiological diagnostic procedures or potentially nephrotoxic drugs should be used with caution. These measures should reduce the rate of progression of chronic kidney disease. Increasing numbers of dialysed HIV-infected patients emphasize the need for the better coordination of care.

Imaging features of renal pathology in the human immunodeficiency virus-infected patient

Renal disease in patients with acquired immunodeficiency syndrome was described before even human immunodeficiency virus was demonstrated to be the causative agent, when the now known human immunodeficiency virus associated nephropathy was first described. Several other pathologic processes mostly relating to the immunodeficiency caused by the virus, such as atypical infections, malignancies, as well as highly active antiretroviral therapy related side affects, have been shown to affect the kidneys. The mortality and morbidity burden is high; therefore, it is paramount the radiologist be familiar with the imaging features of this wide range of diseases processes.