Targeting WIP1 phosphatase promotes partial remission in experimental collapsing glomerulopathy.

Collapsing focal segmental glomerulosclerosis (FSGS), also known as collapsing glomerulopathy (CG), is the most aggressive variant of FSGS and is characterized by a rapid progression to kidney failure. Understanding CG pathogenesis represents a key step for the development of targeted therapies. Previous work implicated the telomerase protein component TERT in CG pathogenesis, as transgenic TERT expression in adult mice resulted in a CG resembling that seen in human primary CG and HIV-associated nephropathy (HIVAN). Here, we used the telomerase-induced mouse model of CG (i-TERTci mice) to identify mechanisms to inhibit CG pathogenesis. Inactivation of WIP1 phosphatase, a p53 target acting in a negative feedback loop, blocked disease initiation in i-TERTci mice. Repression of disease initiation upon WIP1 deficiency was associated with senescence enhancement and required transforming growth factor-ß functions. The efficacy of a pharmacologic treatment to reduce disease severity in both i-TERTci mice and in a mouse model of HIVAN (Tg26 mice) was then assessed. Pharmacologic inhibition of WIP1 enzymatic activity in either the telomerase mice with CG or in the Tg26 mice promoted partial remission of proteinuria and ameliorated kidney histopathologic features. Histological as well as high-throughput sequencing methods further showed that selective inhibition of WIP1 does not promote kidney fibrosis or inflammation. Thus, our findings suggest that targeting WIP1 may be an effective therapeutic strategy for patients with CG.

HIV-1 infection of renal epithelial cells: 30 years of evidence from transgenic animal models, human studies and in vitro experiments.

Although antiretroviral therapy (ART) has increased life expectancy in people with HIV-1 (PWH), acute and chronic kidney disease remain common in this population and are associated with poor outcomes. A broad spectrum of kidney disorders can be observed in PWH, some of which are directly related to intrarenal HIV infection and gene expression. HIV-associated nephropathy (HIVAN) was the most common kidney disease in PWH before ART became available. Animal models and human biopsy studies established the causal relationships between direct HIV-1 infection of renal epithelial cells and HIVAN, expression of viral genes in renal epithelial cells, and dysregulation of host genes involved in cell differentiation and cell cycle. In this review, we provide a summary of the body of work demonstrating HIV-1 infection of epithelial cells in the kidney and recent advancements in the understanding of viral entry mechanisms and consequences of HIV-1 gene expression in those cells.

NEF-Induced HIV-Associated Nephropathy Through HCK/LYN Tyrosine Kinases.

HIV-1-associated nephropathy (HIVAN) is a severe complication of HIV-1 infection. To gain insight into the pathogenesis of kidney disease in the setting of HIV, a transgenic (Tg) mouse model [CD4C/HIV-negative regulator factor (Nef)] was used in which HIV-1 nef expression is under control of regulatory sequences (CD4C) of the human CD4 gene, thus allowing expression in target cells of the virus. These Tg mice develop a collapsing focal segmental glomerulosclerosis associated with microcystic dilatation, similar to human HIVAN. To identify kidney cells permissive to the CD4C promoter, CD4C reporter Tg lines were used. They showed preferential expression in glomeruli, mainly in mesangial cells. Breeding CD4C/HIV Tg mice on 10 different mouse backgrounds showed that HIVAN was modulated by host genetic factors. Studies of gene-deficient Tg mice revealed that the presence of B and T cells and that of several genes was dispensable for the development of HIVAN: those involved in apoptosis (Trp53, Tnfsf10, Tnf, Tnfrsf1b, and Bax), in immune cell recruitment (Ccl3, Ccl2, Ccr2, Ccr5, and Cx3cr1), in nitric oxide (NO) formation (Nos3 and Nos2), or in cell signaling (Fyn, Lck, and Hck/Fgr). However, deletion of Src partially and that of Hck/Lyn largely abrogated its development. These data suggest that Nef expression in mesangial cells through hematopoietic cell kinase (Hck)/Lck/Yes novel tyrosine kinase (Lyn) represents important cellular and molecular events for the development of HIVAN in these Tg mice.

Updates on HIV and Kidney Disease.

PURPOSE OF REVIEW: With the advent of antiretroviral therapy, HIV infection has become a chronic disease in developed countries. RECENT FINDINGS: Non-HIV-driven risk factors for kidney disease, such as APOL1 risk variants and other genetic and environmental factors, have been discovered and are better described. Consequently, the field of HIV-associated kidney disease has evolved with greater attention given to traditional risk factors of CKD and antiretroviral treatment's nephrotoxicity. In this review, we explore risk factors of HIV-associated kidney disease, diagnostic tools, kidney pathology in HIV-positive individuals, and antiretroviral therapy-associated nephrotoxicity.

Apolipoprotein L1 gene variants and kidney disease in patients with HIV: a systematic review and meta-analysis.

BACKGROUND: The risk of various types of kidney disease is significantly increased in the presence of APOL1 high-risk genotype (carriage of two risk alleles), particularly HIV-associated nephropathy (HIVAN). However, there are discrepancies in the existing evidence about the level of association between APOL1 high-risk genotype and the risk of kidney diseases in people living with HIV (PLWHIV). METHODS: This systematic review and meta-analysis was conducted to assess the relationship between the APOL1 genotypes and kidney disease in the HIV population. An a priori protocol registered on PROSPERO (ID: CRD42021253877), was followed by a systematic search of five electronic databases. Database-specific search terms were used to identify observational studies that evaluated the outcomes chosen in the review, based on a set of prespecified eligibility criteria. Using a random effect model, the odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were pooled for the meta-analysis. RESULTS: After screening 4418 citations, 14 articles comprising 11,069 participants were included in this review. The risk of chronic kidney disease (CKD) in the HIV positive population was significantly increased in the presence of two APOL1 risk alleles (OR 4.65 [95% CI 3.51-6.15]). Also, a significant association was observed between the carriage of two risk APOL1 variants and proteinuria (OR 2.58 [95% CI 2.05-3.25]), HIVAN (OR 16.67 [95% CI 10.22-27.19]), and progression to end-stage kidney disease (ESKD) hazard ratio: 1.79 (95% CI 1.20-2.66). CONCLUSION: This review highlights a strong association between the presence of two risk APOL1 variants and an increased risk of kidney disease in PLWHIV, and provides a more precise estimate of the effect size, with smaller 95% CIs for CKD, HIVAN, and progression to ESKD.

HIV-associated nephropathy in children: challenges in a resource-limited setting.

HIV infection remains one of the leading causes of morbidity and mortality worldwide, especially in children living in resource-limited settings. Although the World Health Organization (WHO) recently recommended antiretroviral therapy (ART) initiation upon diagnosis regardless of the number of CD4, ART access remains limited, especially in children living in sub-Saharan Africa (SSA). HIV-infected children who do not receive appropriate ART are at increased risk of developing HIV-associated nephropathy (HIVAN). Although due to genetic susceptibility, SSA is recognized to be the epicenter of HIVAN, limited information is available regarding the burden of HIVAN in children living in Africa. The present review discusses the information available to date on the prevalence, pathogenesis, risk factors, diagnosis, and management of HIVAN in children, focusing on related challenges in a resource-limited setting.

Tubular-specific expression of HIV protein Vpr leads to severe tubulointerstitial damage accompanied by progressive fibrosis and cystic development.

Chronic kidney disease (CKD) is a common cause of morbidity in human immunodeficiency virus (HIV)-positive individuals. HIV infection leads to a wide spectrum of kidney cell damage, including tubular epithelial cell (TEC) injury. Among the HIV-1 proteins, the pathologic effects of viral protein R (Vpr) are well established and include DNA damage response, cell cycle arrest, and cell death. Several in vitro studies have unraveled the molecular pathways driving the cytopathic effects of Vpr in tubular epithelial cells. However, the in vivo effects of Vpr on tubular injury and CKD pathogenesis have not been thoroughly investigated. Here, we use a novel inducible tubular epithelial cell-specific Vpr transgenic mouse model to show that Vpr expression leads to progressive tubulointerstitial damage, interstitial inflammation and fibrosis, and tubular cyst development. Importantly, Vpr-expressing tubular epithelial cells displayed significant hypertrophy, aberrant cell division, and atrophy; all reminiscent of tubular injuries observed in human HIV-associated nephropathy (HIVAN). Single-cell RNA sequencing analysis revealed the Vpr-mediated transcriptomic responses in specific tubular subsets and highlighted the potential multifaceted role of p53 in the regulation of cell metabolism, proliferation, and death pathways in Vpr-expressing tubular epithelial cells. Thus, our study demonstrates that HIV Vpr expression in tubular cells is sufficient to induce HIVAN-like tubulointerstitial damage and fibrosis, independent of glomerulosclerosis and proteinuria. Additionally, as this new mouse model develops progressive CKD with diffuse fibrosis and kidney failure, it can serve as a useful tool to examine the mechanisms of kidney disease progression and fibrosis in vivo.

High risk APOL1 genotypes and kidney disease among treatment naïve HIV patients at Kano, Nigeria.

INTRODUCTION: Racial disparities are known in the occurrence of kidney disease with excess risks found among people of African descent. Apolipoprotein L1 (APOL1) gene variants G1 and G2 are associated with kidney disease among HIV infected individuals of African descent in the USA as well as among black population in South Africa. We set out to investigate the prevalence of these high-risk variants and their effects on kidney disease among HIV infected patients in Northern Nigeria with hitherto limited information despite earlier reports of high population frequencies of these alleles from the Southern part of the country. METHODS: DNA samples obtained from the whole blood of 142 participants were genotyped for APOL1 G1 and G2 variants after initial baseline investigations including assessment of kidney function. Participants comprised 50 HIV positive patients with no evidence of kidney disease, 52 HIV negative individuals with no kidney disease and 40 HIV positive patients with chronic kidney disease (CKD) evidenced by persistent proteinuria and/or reduced eGFR, who also had a kidney biopsy. All the HIV positive patients were newly diagnosed and treatment naïve. RESULTS: The distribution of the APOL1 genotypes among the study participants revealed that 24.6% had a G1 risk allele and 19.0% a G2. The frequency of the High Risk Genotype (HRG) was 12.5% among those with CKD compared to 5.8% in the HIV negative group and zero in the HIV positive no CKD group. Having the HRG was associated with a higher odds for developing HIV Associated Nephropathy (HIVAN) (2 vs 0 risk alleles: OR 10.83, 95% CI 1.38-84.52; P = 0.023; 2 vs 0 or 1 risk alleles: OR 5.5, 95% CI 0.83-36.29; P = 0.07). The HRG was also associated with higher odds for Focal Segmental Glomerulosclerosis (FSGS) (2 vs 0 risk alleles: OR 13.0, 95% CI 2.06-81.91; P = 0.006 and 2 vs 0 or 1 risk alleles: OR 9.0, 95%CI 1.62-50.12; P = 0.01) when compared to the control group. CONCLUSION: This study showed a high population frequency of the individual risk alleles of the APOL1 gene with higher frequencies noted among HIV positive patients with kidney disease. There is high association with the presence of kidney disease and especially FSGS and HIVAN among treatment naive HIV patients carrying two copies of the HRG.

HIV at 40: kidney disease in HIV treatment, prevention, and cure.

Four decades after the first cases of HIV were reported, kidney disease remains an important comorbidity in people with HIV (PWH). Both HIV-associated nephropathy and immune complex kidney disease were recognized as complications of HIV infection in the early years before treatment was available. Although the introduction of effective antiretroviral therapy in the late 1990s resulted in dramatic improvements in survival and health in PWH, several commonly used antiretroviral agents have been associated with kidney injury. HIV infection and treatment may also promote the progression of comorbid chronic kidney disease due to traditional risk factors such as diabetes, and HIV is one of the strongest "second hits" for the high-risk APOL1 genotype. Unique considerations in the management of chronic kidney disease in PWH are largely related to the need for lifelong antiretroviral therapy, with potential for toxicity, drug-drug interactions, and polypharmacy. PWH who develop progressive chronic kidney disease are candidates for all modalities of kidney replacement therapy, including kidney transplantation, and at some centers, PWH may be candidates to serve as donors for recipients with HIV. Transplantation of kidney allografts from donors with HIV also offers a unique opportunity to study viral dynamics in the kidney, with implications for kidney health and for research toward HIV cure. In addition, HIV-transgenic animal models have provided important insights into kidney disease pathogenesis beyond HIV, and experience with HIV and HIV-related kidney disease has provided important lessons for future pandemics.

Acompanhamento do comportamento do HIV através de exames laboratoriais em portadora do vírus: relato de caso / Monitoring of HIV behavior through laboratory tests in a virus carrier: case report

O vírus da imunodeficiência humana é o agente etiológico da AIDS, doença crônica que destrói o sistema imunológico e é caracterizada pela baixa contagem de células TCD4, alta contagem de partículas virais no sangue e manifestações clínicas da doença. O diagnóstico se dá com o aparecimento de infecções oportunistas, que levam a contagem de TCD4 a níveis menores que 200 céls/mm³. Os exames laboratoriais para o diagnóstico do HIV foram os principais avanços para o início do tratamento, reduzindo a transmissão. Detecção de anticorpos, detecção de antígenos e amplificação do genoma do vírus são alguns dos exames laboratoriais utilizados para diagnóstico. Os dois principais biomarcadores são os exames de contagem de células TCD4, que verifica o sistema imune, e a quantificação de carga viral, que informa a quantidade de partículas virais, mostrando a progressão da infecção. Quanto maior a carga viral, maior o dano ao sistema imune. Uma carga viral indetectável é inferior a 50 cópias/mL, mas valores menores ou iguais a 200 cópias/mL também impedem a transmissão. Uma declaração de consenso afirma que Indetectável é igual a Intransmissível. Portanto, quando indetectável, a transmissão inexiste. O presente estudo relata e discute o caso clínico de uma paciente diagnosticada com HIV/AIDS aos 28 anos, que sobreviveu, apesar do diagnóstico tardio, e sob presença de doença oportunista com um grave grau de diminuição de células TCD4 (22 cél/mm³). Por meio do diagnóstico, introdução e adesão correta da terapia antirretroviral e monitorização de exames laboratoriais, conseguiu evitar a morte e ter uma vida semelhante à de um HIV negativo. Ultrapassou a expectativa de vida que na descoberta era de 10 anos, com uma qualidade de vida considerável, não sendo transmissora do vírus, diminuindo assim o estigma e preconceito. O biomédico é peça fundamental nesse contexto, considerando que deve fornecer informações precisas e fidedignas, tão necessárias ao acompanhamento de pessoas vivendo com HIV, para que autoridades e profissionais de saúde adotem medidas adequadas, tanto na prevenção, quanto no diagnóstico e monitoramento da doença.

The human immunodeficiency virus is the etiological agent of AIDS, a chronic disease that destroys the immune system and is characterized by low TCD4 cell count, high viral particle count in blood and clinical manifestations of the disease. The diagnosis is due to the appearance of opportunistic infections, which lead to TCD4 counts below 200 cells / mm³. Laboratory tests for the diagnosis of HIV were the main advances in starting treatment, reducing transmission. Antibody detection, antigen detection and virus genome amplification are some of the laboratory tests used for diagnosis. The two main biomarkers are the TCD4 cell count tests, which checks the immune system, and viral load quantification, which reports the number of viral particles, showing the progression of infection. The higher the viral load, the greater the damage to the immune system. An undetectable viral load is less than 50 copies / mL, but values less than or equal to 200 copies / mL also prevent transmission. A consensus statement states that Undetectable equals Non-Transmissible. Therefore, when undetectable, transmission does not exist. The present study reports and discusses the clinical case of a patient diagnosed with HIV / AIDS at age 28, who survived despite late diagnosis and under the presence of opportunistic disease with a severe degree of TCD4 cell reduction (22 cells / mm³). Through the diagnosis, introduction and correct adherence of antiretroviral therapy and monitoring of laboratory tests, she was able to avoid death and have a life similar to that of an HIV negative. Exceeded the life expectancy that in the discovery was 10 years, with a considerable quality of life, not transmitting the virus, thus reducing the stigma and prejudice. The biomedical is a key player in this context, considering that he must provide accurate and reliable information, which is so necessary for the monitoring of people living with HIV, so that authorities and health professionals adopt appropriate measures, both in prevention, diagnosis and monitoring of the disease.

Clinicopathological correlation of kidney disease in HIV infection pre- and post-ART rollout.

The spectrum of HIV-associated kidney disease has expanded significantly with the introduction of antiretroviral therapy (ART). In the pre-ART era there was prominence of HIV-associated nephropathy (HIVAN). More recently, the spectrum of disease additionally reflects comorbid illness in the ageing HIV population and ART-related nephrotoxicity. We performed a clinicopathological correlation of kidney disease in HIV-positive individuals who underwent kidney biopsy between 1989 and 2014, utilizing the 2018 Kidney Disease Improving Global Outcomes pathologic classification. ART rollout began in 2004 in South Africa. Patients biopsied pre-ART rollout were compared to those biopsied post-ART rollout with respect to demographics, clinical parameters and histology. We assessed kidney survival in a cohort of these patients following biopsy. Six hundred and ninety biopsies were included, 99 (14.3%) were undertaken pre- and 591 (85.7%) post-ART rollout. Most patients were of Black African descent (97.5%). The post-ART rollout patients were older (p = 0.007), had higher eGFR at presentation (p = 0.016) and fewer presented with eGFR of less than 15ml/min/1.73m2 (p = 0.0008). There was a decrease in the prevalence of classic HIVAN (p = 0.00001); and an increase in FSGS (NOS) in the setting of HIV (p = 0.0022) and tubulointerstitial diseases (p = 0.009) post-ART rollout. Kidney function survival over 5 years was poorest in patients with classic HIVAN (p = 0.00005) and best in minimal change nephropathy (p = 0.0013). Kidney biopsy is crucial for the correct diagnosis and management of HIV-related kidney disease. ART rollout has shifted the spectrum of kidney disease away from classic HIVAN but has not eliminated it. Histological diagnosis prognosticates kidney survival.

Characterization of HIV-1 Infection in Microglia-Containing Human Cerebral Organoids.

The achievement of an HIV cure is dependent on the eradication or permanent silencing of HIV-latent viral reservoirs, including the understudied central nervous system (CNS) reservoir. This requires a deep understanding of the molecular mechanisms of HIV's entry into the CNS, latency establishment, persistence, and reversal. Therefore, representative CNS culture models that reflect the intercellular dynamics and pathophysiology of the human brain are urgently needed in order to study the CNS viral reservoir and HIV-induced neuropathogenesis. In this study, we characterized a human cerebral organoid model in which microglia grow intrinsically as a CNS culture model to study HIV infection in the CNS. We demonstrated that both cerebral organoids and isolated organoid-derived microglia (oMG), infected with replication-competent HIVbal reporter viruses, support productive HIV infection via the CCR5 co-receptor. Productive HIV infection was only observed in microglial cells. Fluorescence analysis revealed microglia as the only HIV target cell. Susceptibility to HIV infection was dependent on the co-expression of microglia-specific markers and the CD4 and CCR5 HIV receptors. Altogether, this model will be a valuable tool within the HIV research community to study HIV-CNS interactions, the underlying mechanisms of HIV-associated neurological disorders (HAND), and the efficacy of new therapeutic and curative strategies on the CNS viral reservoir.

Impact of Antiretroviral Therapy on Kidney Disease in HIV Infected Individuals - A Qualitative Systematic Review.

Kidney disease is the fourth most common cause of non-AIDS-related mortality in people living with HIV. Combination antiretroviral therapy (cART) remains the cornerstone of treatment. However, little is known about the impact of cART on disease outcomes in patients with HIV-associated nephropathy (HIVAN) and HIV-immune complex kidney disease (HIVICK). This systematic review evaluates the impact of cART on progression to end-stage kidney disease (ESKD) and other outcomes in HIV-infected individuals. We conducted a literature search utilizing PubMed, and Cochrane database and 11 articles met inclusion criteria for analysis of which nine HIVAN studies showed decreased progression to ESKD or death for subjects when treated with cART versus those untreated. However, two studies showed no survival advantage with cART. Three HIVICK studies showed improvement in delaying ESKD in subjects on cART compared to untreated subjects. cART appeared to reduce the risk to ESKD or death in patients with both HIVAN and HIVICK.

The spectrum of kidney biopsy findings in Chinese HIV-infected patients.

OBJECTIVES: HIV-associated kidney disease is common but data on the pathology spectrum of kidney biopsy in China is lacking. This study aimed to illustrate the clinical presentation, laboratory findings and pathological spectrum of different subtypes of HIV-associated kidney disease in China. METHODS: Eighteen HIV patients with renal biopsy indications at the Peking Union Medical College Hospital from January 2002 to October 2021 were retrospectively enrolled. All had CD4 counts and HIV viral load measurements. Renal biopsies were examined with light microscopy, immunofluorescence, and electron microscopy. Shapiro-Wilk test was used to test whether the data was normally distributed. The data is presented as medians (interquartile range), number (%), or means (±SD) according to their distribution. RESULTS: Seventeen patients had glomerular disease, and one patient had interstitial nephritis. Membranous nephropathy was present in eight patients (47.1%), and IgA nephropathy in four patients (23.5%). The difference in urine protein and serum albumin before and after treatment was statistically significant and no deaths or dialysis were observed to the end of follow-up. CONCLUSION: This study found that classic HIV-associated nephropathy (HIVAN) was uncommon in Chinese HIV patients. HIV immune complex kidney (HIVICK) disease, such as membranous or IgA nephropathy, was more common, and associated with better prognosis. Antiretroviral therapy, ACE inhibitors, and angiotensin II receptor blockers were effective in decreasing proteinuria and preserving renal function. The use of corticosteroids and immunosuppressive agents seems safe. However, the nephrotoxic effect of antiretroviral agents and other medications should be carefully monitored.

GWAS in Mice Maps Susceptibility to HIV-Associated Nephropathy to the Ssbp2 Locus.

BACKGROUND: To gain insight into the pathogenesis of collapsing glomerulopathy, a rare form of FSGS that often arises in the setting of viral infections, we performed a genome-wide association study (GWAS) among inbred mouse strains using a murine model of HIV-1 associated nephropathy (HIVAN). METHODS: We first generated F1 hybrids between HIV-1 transgenic mice on the FVB/NJ background and 20 inbred laboratory strains. Analysis of histology, BUN, and urinary NGAL demonstrated marked phenotypic variation among the transgenic F1 hybrids, providing strong evidence for host genetic factors in the predisposition to nephropathy. A GWAS in 365 transgenic F1 hybrids generated from these 20 inbred strains was performed. RESULTS: We identified a genome-wide significant locus on chromosome 13-C3 and multiple additional suggestive loci. Crossannotation of the Chr. 13 locus, including single-cell transcriptomic analysis of wildtype and HIV-1 transgenic mouse kidneys, nominated Ssbp2 as the most likely candidate gene. Ssbp2 is highly expressed in podocytes, encodes a transcriptional cofactor that interacts with LDB1 and LMX1B, which are both previously implicated in FSGS. Consistent with these data, older Ssbp2 null mice spontaneously develop glomerulosclerosis, tubular casts, interstitial fibrosis, and inflammation, similar to the HIVAN mouse model. CONCLUSIONS: These findings demonstrate the utility of GWAS in mice to uncover host genetic factors for rare kidney traits and suggest Ssbp2 as susceptibility gene for HIVAN, potentially acting via the LDB1-LMX1B transcriptional network.

Prevalence and risk factors of chronic kidney disease in an HIV positive Mexican cohort.

BACKGROUND: HIV subjects have several kidney pathologies, like HIV-associated nephropathy or antiretroviral therapy injury, among others. The global prevalence of Chronic Kidney Disease (CKD) is 8-16%; however, in HIV subjects, the prevalence varies between geographic regions (2-38%). The aim was to determine the prevalence of CKD and identify the associated risk factors. METHODS: A longitudinal descriptive study was carried out at the 'Hospital Civil de Guadalajara' Feb'18 - Jan'19. Basal clinical, demographic, opportunistic infections (OI), and laboratory data were obtained at months 0 and 3; inclusion criteria were ≥ 18 years old, naïve HIV + , urine albumin/creatinine ratio, serum creatinine & urine test, and signed informed consent. Descriptive and multiple logistic regression statistical analyses were made. RESULTS: One hundred twenty subjects were included; 92.5% were male, 33 ± 9.5 years, 60% consumed tobacco, 73% alcohol, and 59% some type of drug. The CKD prevalence was 15.8%. CKD patients had a higher risk of hepatitis C virus coinfection, Relative Risk (RR):5.9; HCV infection, RR:4.3; ≥ 30 years old, RR:3.9; C clinical-stage, RR:3.5; CD4+ T cells count < 200 cells/µL, RR: 2.4; and HIV-1 viral load ≥ 100,000 cop/mL, RR: 2.7. CONCLUSIONS: Our study showed a higher CKD prevalence in patients with HIV; higher CKD development with coinfections as Hepatitis C Virus and Mycobacterium tuberculosis. The identification and prompt management of CKD and coinfections should be considered to avoid the progression and to delay renal replacement therapy as long as possible.

Recessive, gain-of-function toxicity in an APOL1 BAC transgenic mouse model mirrors human APOL1 kidney disease.

People of recent sub-Saharan African ancestry develop kidney failure much more frequently than other groups. A large fraction of this disparity is due to two coding sequence variants in the APOL1 gene. Inheriting two copies of these APOL1 risk variants, known as G1 and G2, causes high rates of focal segmental glomerulosclerosis (FSGS), HIV-associated nephropathy and hypertension-associated end-stage kidney disease. Disease risk follows a recessive mode of inheritance, which is puzzling given the considerable data that G1 and G2 are toxic gain-of-function variants. We developed coisogenic bacterial artificial chromosome (BAC) transgenic mice harboring either the wild-type (G0), G1 or G2 forms of human APOL1. Expression of interferon gamma (IFN-γ) via plasmid tail vein injection results in upregulation of APOL1 protein levels together with robust induction of heavy proteinuria and glomerulosclerosis in G1/G1 and G2/G2 but not G0/G0 mice. The disease phenotype was greater in G2/G2 mice. Neither heterozygous (G1/G0 or G2/G0) risk variant mice nor hemizygous (G1/-, G2/-) mice had significant kidney injury in response to IFN-γ, although the heterozygous mice had a greater proteinuric response than the hemizygous mice, suggesting that the lack of significant disease in humans heterozygous for G1 or G2 is not due to G0 rescue of G1 or G2 toxicity. Studies using additional mice (multicopy G2 and a non-isogenic G0 mouse) supported the notion that disease is largely a function of the level of risk variant APOL1 expression. Together, these findings shed light on the recessive nature of APOL1-nephropathy and present an important model for future studies.

PATHOMORPHOLOGICAL CHARACTERISTICS OF IMMUNOCOMPLEX RENAL DISEASE IN PATIENTS WITH IMMUNODEFICIENCY VIRUS AND HEPATITIS C VIRUS, RECEIVING ANTIRETROVIRAL THERAPY.

OBJECTIVE: The aim is to verify and describe the morphological substrate of renal impairment in HIV/HCV co-infection among patients receiving ART to assess and predict the morphogenesis of immunocomplex lesions. PATIENTS AND METHODS: Materials and methods: To assess and predict the morphogenesis of immunocomplex renal disease, we examined retrospectively the kidney tissue samples of 15 patients, who died with HIV/HCV co-infection and received ART. Histological, histochemical and immunohistochemical research methods were used. RESULTS: Results: Segmental and diffuse mesangial proliferation with extracellular matrix expansion with glomerular damage ≥50% in 9 (60%) cases, and involving <50% of glomeruli in 5 (33%), with CD68 expression as single cells were detected. In 12 (80%) cases, there was uneven swelling and focal proliferation of endothelial cells with the involvement of 20-50% of the glomeruli, as well as the presence of cellular infiltrates in the lumen of capillary loops in 3 (20%) cases with monomorphic intensity in "+". Sclerotic changes were present in various degrees of severity - from cases of complete glomerulosclerosis with obliteration of the Bowman's lumen to focal and microfocal depressions 8 (55%), sclerosis 10 (66%), hyalinosis 1 (6%), uneven thickening, focal cleft 8 (55%) and perihilar focal sclerosis. These areas were positive for IgG and C1q complement fractions within the "+", "++" intensity. Among the study group, no case of HIV-associated nephropathy was found that coincided with the predicted spectrum of kidney damage for patients in this sample. The described morphological changes were mainly verified as immuno-mediated by HCV. CONCLUSION: Conclusions: A comprehensive morphological study revealed the morphological substrate of kidney damage and its morphogenesis in patients with HIV/HCV co-infection, receiving ART.

Regional and Racial Disparities in HIV-Related Kidney Disease.

Clinical Background and Epidemiology: Worldwide, an estimated 38 million people are living with HIV infection. The classic kidney disease of HIV infection, commonly known as HIV-associated nephropathy, is a collapsing form of focal segmental glomerulosclerosis that almost exclusively affects individuals of African descent with advanced HIV disease. People living with HIV are also at risk for immune-complex kidney diseases, antiretroviral nephrotoxicity, and kidney disease due to co-infections and comorbidities. Challenges: The burden of HIV-related kidney disease is greatest in traditionally disadvantaged populations in resource-limited settings in sub-Saharan Africa and the Caribbean and among minority populations in the United States and Europe. Factors contributing to these disparities include a higher prevalence of HIV infection, limited access to optimal antiretroviral therapy, and genetic susceptibility to kidney disease. Treatment and Prevention: Current treatment guidelines recommend the initiation of life-long antiretroviral therapy in all people living with HIV to prevent AIDS and non-AIDS complications, including kidney disease. People living with HIV who progress to end-stage kidney disease despite treatment are candidates for dialysis and kidney transplant, including the possibility of accepting organs from HIV-positive donors in some settings. Although HIV prevention is currently the only definitive solution, expanding access to antiretroviral therapy, dialysis, and kidney transplantation in people living with HIV are important intermediate steps to address the global burden of HIV-related kidney disease.

Circulating fibroblast growth factor-2 precipitates HIV nephropathy in mice.

People of African ancestry living with the human immunodeficiency virus-1 (HIV-1) are at risk of developing HIV-associated nephropathy (HIVAN). Children with HIVAN frequently show high plasma fibroblast growth factor-2 (FGF-2) levels; however, the role of circulating FGF-2 in the pathogenesis of childhood HIVAN is unclear. Here, we explored how circulating FGF-2 affected the outcome of HIVAN in young HIV-Tg26 mice. Briefly, we demonstrated that FGF-2 was preferentially recruited in the kidneys of mice without pre-existing kidney disease, precipitating HIVAN by activating phosphorylated extracellular signal-regulated kinase (pERK) in renal epithelial cells, without inducing the expression of HIV-1 genes. Wild-type mice injected with recombinant adenoviral FGF-2 (rAd-FGF-2) vectors carrying a secreted form of human FGF-2 developed transient and reversible HIVAN-like lesions, including proteinuria and glomerular enlargement. HIV-Tg26 mice injected with rAd-FGF-2 vectors developed more-significant proliferative and pro-fibrotic inflammatory lesions, similar to those seen in childhood HIVAN. These lesions were partially reversed by treating mice with the FGF/VEGF receptor tyrosine kinase inhibitor PD173074. These findings suggest that high plasma FGF-2 levels may be an independent risk factor for precipitating HIVAN in young children.