Kidney disease in HIV-positive children. Semin Nephrol. 2008;28:585-594. [PMID: 19013330 DOI: 10.1016/j.semnephrol.2008.09.001]

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.

Association of circulating fibroblast growth factor-2 with progression of HIV-chronic kidney diseases in children

BACKGROUND

Children living with HIV frequently show high plasma levels of fibroblast growth factor-2 (FGF-2/bFGF). FGF-2 accelerates the progression of several experimental kidney diseases; however, the role of circulating FGF-2 in childhood HIV-chronic kidney diseases (HIV-CKDs) is unknown. We carried out this study to determine whether high plasma FGF-2 levels were associated with the development of HIV-CKDs in children.

METHODS

The plasma and urine FGF-2 levels were measured in 84 children (< 12 years of age) living with HIV during the pre-modern antiretroviral era, and followed for at least 3 years to determine the prevalence of proteinuria and HIV-CKDs. We also assessed the distribution of the kidney FGF-2 binding sites by autoradiography and Alcian blue staining, and explored potential mechanisms by which circulating FGF-2 may precipitate HIV-CKDs in cultured kidney epithelial and mononuclear cells derived from children with HIV-CKDs.

RESULTS

High plasma FGF-2 levels were associated with a high viral load. Thirteen children (~ 15%) developed HIV-CKDs and showed a large reservoir of FGF-2 low-affinity binding sites in the kidney, which can facilitate the recruitment of circulating FGF-2. Children with high plasma and urine FGF-2 levels had 73-fold increased odds (95% CI 9-791) of having HIV-CKDs relative to those with normal FGF-2 values. FGF-2 induced the proliferation and decreased the expression of APOL-1 mRNA in podocytes, and increased the attachment and survival of infected mononuclear cells cultured from children with HIV-CKDs.

CONCLUSIONS

High plasma FGF-2 levels appear to be an additional risk factor for developing progressive childhood HIV-CKDs.

Childhood HIV-associated nephropathy: 36 years later

HIV-associated nephropathy (HIVAN) predominantly affects people of African ancestry living with HIV who do not receive appropriate antiretroviral therapy (ART). Childhood HIVAN is characterized by heavy proteinuria and decreased kidney function. Kidney histology shows mesangial expansion, classic or collapsing glomerulosclerosis, and microcystic renal tubular dilatation leading to kidney enlargement. The pathogenesis of HIVAN involves the kidney recruitment of inflammatory cells and the infection of kidney epithelial cells. In addition, both viral and genetic factors play key roles in this disease. Modern ART has improved the outcome and decreased the prevalence of childhood HIVAN. However, physicians have had modest success providing chronic ART to children and adolescents, and we continue to see children with HIVAN all over the world. This article discusses the progress made during the last decade in our understanding of the pathogenesis and treatment of childhood HIVAN, placing particular emphasis on the mechanisms that mediate the infection of kidney epithelial cells, and the roles of cytokines, the HIV-Tat gene, and the Apolipoprotein-1 (APOL1) gene risk variants in this disease. In view of the large number of children living with HIV at risk of developing HIVAN, better prevention and treatment programs are needed to eradicate this disease.

Racial differences of early vascular aging in children and adolescents

The prevalence of non-communicable disease (NCDs) is rising globally, with a large burden recorded in sub-Saharan countries and populations of black race/ethnicity. Accelerated vascular deterioration, otherwise known as early vascular aging (EVA), is the underlying factor for highly prevalent NCDs such as hypertension. The etiology of EVA is multifactorial with a central component being arterial stiffness with subsequent development of hypertension and cardiovascular complications. Although arterial stiffness develops with increasing age, many children and adolescents are subjected to the premature development of arterial stiffness, due to genetic or epigenetic predispositions, lifestyle and behavioral risk factors, and early life programming. Race/ethnic differences in pediatric populations have also been reported with higher aortic stiffness in black (African American) compared with age-matched white (European American) counterparts independent of blood pressure, body mass index, or socioeconomic status. With known evidence of race/ethnic differences in EVA, the pathophysiological mechanisms underlying graded differences in the programming of EVA are still sparse and rarely explored. This educational review aims to address the early life determinants of EVA in children and adolescents with a particular focus on racial or ethnic differences.

HIV-Associated CKDs in Children and Adolescents

INTRODUCTION

Limited information is available describing the current prevalence of proteinuria and HIV-associated CKDs (HIV-CKDs) in children and adolescents living with HIV and receiving antiretroviral therapy in the United States.

METHODS

To address this issue, we performed a retrospective study of children and adolescents living with HIV who received medical care at Children's National Hospital in Washington, DC, between January 2012 and July 2019. Demographic data, clinical parameters (mode of HIV transmission, viral loads, CD4 cell counts, serum creatinine, glomerular filtration rate [GFR], plasma lipid levels, proteinuria, blood pressure, renal biopsies), and medical treatments, all done as a standard of clinical care, were collected and analyzed.

RESULTS

The majority of the 192 patients enrolled were of African descent (88%) and acquired HIV through vertical transmission (97%). The prevalence of all HIV-CKDs was 6%. Of these patients, 39% had intermittent or persistent proteinuria, and 7% percent had proteinuria with a mild decline in GFR (60-80 ml/min per 1.73 m2), and 6% had a mild decline in GFR without proteinuria. Documented hypertension was present in 6% of the patients, mainly in association with HIV-CKD. Patients with persistent proteinuria (3%) and biopsy-proven HIV-CKD had a slow but constant progression of their renal diseases.

CONCLUSIONS

The prevalence of persistent proteinuria and HIV-CKD was lower than that reported in previous studies conducted in the United States. However, intermittent proteinuria, mild reductions in GFR, and progression of established HIV-CKD were common findings in this group of patients with predominantly vertically acquired HIV who were receiving antiretroviral therapy.

An HIV-Tat inducible mouse model system of childhood HIV-associated nephropathy

Modern antiretroviral therapies (ART) have decreased the prevalence of HIV-associated nephropathy (HIVAN). Nonetheless, we continue to see children and adolescents with HIVAN all over the world. Furthermore, once HIVAN is established in children, it is difficult to revert its long-term progression, and we need better animal models of childhood HIVAN to test new treatments. To define whether the HIV-1 trans-activator (Tat) gene precipitates HIVAN in young mice, and to develop an inducible mouse model of childhood HIVAN, an HIV-Tat gene cloned from a child with HIVAN was used to generate recombinant adenoviral vectors (rAd-Tat). rAd-Tat and LacZ control vectors (2×109) were expressed in the kidney of newborn wild-type and HIV-transgenic (Tg26) FVB/N mice without significant proteinuria (n=5; 8 per group). Mice were sacrificed 7 and 35 days later to assess their renal outcome, the expression of HIV-genes and growth factors, and markers of cell growth and differentiation by RT-qPCR, immunohistochemistry and/or western blots. HIV-Tat induced the expression of HIV-1 genes and heparin-binding growth factors in the kidney of HIV-Tg26 mice, and precipitated HIVAN in the first month of life. No significant renal changes were detected in wild-type mice infected with rAd-Tat vectors, suggesting that HIV-Tat alone does not induce renal disease. This new mouse model of childhood HIVAN highlights the critical role that HIV-Tat plays in the pathogenesis of HIVAN, and could be used to study the pathogenesis and treatment of HIVAN in children and adolescents.

Correlation between CD4 count and glomerular filtration rate or urine protein:creatinine ratio in human immunodeficiency virus-infected children

Background

Studies on kidney complications in human immunodeficiency virus (HIV)-infected children are lacking. CD4 T lymphocytes are an important immune functions regulator and used as a basis for initiating antiretroviral therapy (ART) and monitoring disease progression. This study aims to determine the correlation between CD4 and estimated glomerular filtration rate (eGFR) or urine protein:creatinine ratio (uPCR) as markers of kidney complications.

Methods

This cross sectional study was conducted on HIV-infected children aged 5 to 18 years who visited the Teratai HIV Clinic at Hasan Sadikin Hospital for monthly monitoring in June 2019. CD4 count, eGFR based on the Schwartz formula, and uPCR were obtained. Correlation analysis was performed with the Pearson test.

Results

Subjects were 42 HIV-infected children, consisting of 23 males (54.8%) and 19 females (45.2%). Most children (65.0%) were in an advanced clinical stage and had been diagnosed with HIV for an average of 8 ± 3 years. All subjects had received ART, and six received tenofovir. Compliance to medications were good, and most subjects (79.0%) had normal nutritional status and CD4 count. All subjects had eGFR > 90 mL/min/1.73 m², of which 21 (50.0%) were above normal value. Proteinuria was found in 12 patients (28.6%), and it was not significantly associated with clinical stages of HIV infection. CD4 count was correlated positively with eGFR (r = 0.473, P = 0.001) and negatively with uPCR (r = -0.284, P = 0.034).

Conclusion

The degree of immunodeficiency appears to correlate with severity of renal injury. Screening at diagnosis and periodic monitoring of kidney functions are crucial in all childhood HIV patients.

Accelerated aging in perinatally HIV-infected children: clinical manifestations and pathogenetic mechanisms

Background: Premature aging and related diseases have been documented in HIV-infected adults. Data are now emerging also regarding accelerated aging process in HIV-infected children.

Methods: A narrative review was performed searching studies on PubMed published in English language in 2004-2017, using appropriate key words, including “aging”, “children”, “HIV”, “AIDS”, “immunosenescence”, “pathogenesis”, “clinical conditions”.

Results: Premature immunosenescence phenotype of B and T cells in HIV-infected children is mediated through immune system activation and chronic inflammation. Ongoing inflammation processes have been documented by increased levels of pathogen-associated molecular patterns (PAMPS), increased mitochondrial damage, higher levels of pro-inflammatory cytokines, and a positive correlation between sCD14 levels and percentages of activated CD8⁺ cells. Other reported features of premature aging include cellular replicative senescence, linked to an accelerated telomeres shortening. Finally, acceleration of age-associated methylation pattern and other epigenetic modifications have been described in HIV-infected children. All these features may favor the clinical manifestations related to premature aging. Lipid and bone metabolism, cancers, cardiovascular, renal, and neurological systems should be carefully monitored, particularly in children with detectable viremia and/or with CD4/CD8 ratio inversion.

Conclusion: Aging processes in children with HIV infection impact their quality and length of life. Further studies regarding the mechanisms involved in premature aging are needed to search for potential targets of treatment.

Blood-borne viral infections in pediatric hemodialysis

Hemodialysis patients are at increased risk for development of blood-borne viral infections. Human immunodeficiency virus (HIV), a once fatal infection, has become treatable, but continues to be associated with increased mortality. Hepatitis B and C viral infections can lead to acute and chronic hepatitis, cirrhosis, or hepatocellular carcinoma. Young children and immunocompromised patients are more likely to develop chronic disease leading to increased morbidity and mortality, as compared to the healthy population. The hemodialysis population is at increased risk of blood-borne viral infections as compared to the general population due to multiple factors. Here we review risk factors of blood-borne viral infections, strategies for prevention, and approach to therapy in the pediatric hemodialysis population.

Prevalence of risk factors for chronic kidney disease in South African youth with perinatally acquired HIV

BACKGROUND

Little is known about renal pathology among perinatally HIV-infected children and adolescents in Africa. We assessed the prevalence of risk factors for chronic kidney disease in South African children and adolescents with perinatally acquired HIV-1 (HIV+) on antiretroviral therapy (ART) and HIV-negative children and adolescents.

METHODS

HIV+ youth aged 9-14 years, on ART for > 6 months and age-matched HIV-negative children and adolescents were eligible for assessment of proteinuria and microalbuminuria using urine dipstick and Vantage analyser method. Blood pressure, estimated glomerular filtration rate, HIV-related variables and metabolic co-morbidities were assessed at enrolment.

RESULTS

Among 620 children and adolescents, 511 were HIV+. The median age was 12.0 years and 50% were female. In HIV+ children and adolescents, 425 (83.2%) had a CD4 count > 500 cells/mm3 and 391 (76.7%) had an undetectable viral load. The median duration of ART was 7.6 years (IQR 4.6-9.3) with 7 adolescents receiving Tenofovir. The prevalence of any proteinuria, microalbuminuria and hypertension was 6.6%, 8.5% and 13.9%, respectively, with no difference between HIV+ and negative children and adolescents. All participants had a normal glomerular filtration rate. There was no association between metabolic co-morbidities and microalbuminuria.

CONCLUSIONS

Proteinuria and microalbuminuria appear to be uncommon in this population. Follow up of those with microalbuminuria may inform long-term outcomes and management of this growing population of HIV+ youth.

A review of renal disease in children with HIV infection

Human immunodeficiency virus (HIV) infection continues to be a leading cause of morbidity and mortality. HIV-infected individuals are now surviving for a relatively longer period and this is because of easy accessibility to antiretroviral therapy these days. As a result, chronic disease-related complications are now being recognized more often. Kidney disease in HIV-infected children can vary from glomerular to tubular-interstitial involvement. We searched the database to identify various kidney diseases seen in HIV-infected children. We describe the epidemiology, pathogenesis, pathology, clinical and laboratory manifestations, management and outcome of commonly seen kidney disease in HIV-infected children. We also provide a brief overview of toxicity of antiretroviral drugs seen in HIV-infected children. Kidney involvement in HIV-infected children may arise because of HIV infection per se, opportunistic infections, immune mediated injury and drug toxicity. HIV-associated nephropathy is perhaps the most common and most severe form of kidney disease. Proteinuria may be a cost-effective screening test in the long-term management of HIV-infected children, however, there are no definite recommendations for the same. Other important renal diseases are HIV immune complex kidney disease, thrombotic microangiopathy, interstitial nephritis and vasculitis.

Brief Report: APOL1 Renal Risk Variants Are Associated With Chronic Kidney Disease in Children and Youth With Perinatal HIV Infection

APOL1 renal risk alleles are associated with chronic kidney disease (CKD) in adults, with the strongest effect being for HIV-associated nephropathy. Their role in youth with perinatal HIV-1 infection (PHIV) has not been studied. In a nested case-control study of 451 PHIV participants in the Pediatric HIV/AIDS Cohort Study, we found a 3.5-fold increased odds of CKD in those carrying high-risk APOL1 genotypes using a recessive model [95% confidence interval (CI): 1.2 to 10.0]. We report an unadjusted incidence of 1.2 CKD cases/100 person-years (95% CI: 0.5 to 2.5) in PHIV youth carrying APOL1 high-risk genotypes, with important implications for sub-Saharan Africa.

Proteinuria in HIV-infected Indian children

Chronic kidney disease (CKD) is a major cause of morbidity and mortality among individuals with HIV infection. Screening for proteinuria in HIV-infected children will help in early detection and treatment, and thus prevention and progression to CKD to end-stage kidney disease (ESRD). We screened 139 HIV-infected children aged 18 months to 18 years for proteinuria by urinary dipstick and confirmed by spot urine protein-to-creatinine ratio. If proteinuria was absent by the above methods, patients were screened for microalbuminuria by urinary albumin to creatinine ratio. We found proteinuria in 11.5% and microalbuminuria in 10.6% of our study population. The prevalence of proteinuria was higher in the advanced stages; 8.05% in stage 1, 12.12% in stage 2 and 26.32% in stages 3 + 4.

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.

Circulating Fibroblast Growth Factor-2, HIV-Tat, and Vascular Endothelial Cell Growth Factor-A in HIV-Infected Children with Renal Disease Activate Rho-A and Src in Cultured Renal Endothelial Cells

Renal endothelial cells (REc) are the first target of HIV-1 in the kidney. The integrity of REc is maintained at least partially by heparin binding growth factors that bind to heparan sulfate proteoglycans located on their cell surface. However, previous studies showed that the accumulation of two heparin-binding growth factors, Vascular Endothelial Cell Growth Factor-A (VEGF-A) and Fibroblast Growth Factor-2 (FGF-2), in combination with the viral protein Tat, can precipitate the progression of HIV-renal diseases. Nonetheless, very little is known about how these factors affect the behavior of REc in HIV+ children. We carried out this study to determine how VEGF-A, FGF-2, and HIV-Tat, modulate the cytoskeletal structure and permeability of cultured REc, identify key signaling pathways involved in this process, and develop a functional REc assay to detect HIV+ children affected by these changes. We found that VEGF-A and FGF-2, acting in synergy with HIV-Tat and heparin, affected the cytoskeletal structure and permeability of REc through changes in Rho-A, Src, and Rac-1 activity. Furthermore, urine samples from HIV+ children with renal diseases, showed high levels of VEGF-A and FGF-2, and induced similar changes in cultured REc and podocytes. These findings suggest that FGF-2, VEGF-A, and HIV-Tat, may affect the glomerular filtration barrier in HIV+ children through the induction of synergistic changes in Rho-A and Src activity. Further studies are needed to define the clinical value of the REc assay described in this study to identify HIV+ children exposed to circulating factors that may induce glomerular injury through similar mechanisms.

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.

HIV-associated immune complex kidney disease

The introduction in the late 20(th) century of combination antiretroviral therapy (cART) to treat patients infected with HIV has changed the natural history of the disease from an acute illness that rapidly culminates in death, to a chronic condition that can be managed with medications. Over the past decade the epidemiology of kidney disease in US patients infected with HIV has changed, perhaps because of the increased availability and use of cART. Patients with HIV infection exhibit unique immunologic characteristics, including immunodeficiency and dysregulation of immunoglobulin synthetic responses and T-cell function, which can result in glomerular immune complex deposition and subsequent kidney injury. This Review examines the differential diagnoses of HIV-associated immune complex kidney diseases (HIVICD), and discusses the clinical manifestations and mechanisms underlying their development. We address the issues associated with treatment, clinical outcomes, and research needs to enhance our ability to diagnose and optimally treat patients with HIVICD.

Infectious Diseases and the Kidney in Children

The kidney is involved in a wide range of bacterial, viral, fungal, and parasitic diseases. In most systemic infections, renal involvement is a minor component of the illness, but in some, renal failure may be the presenting feature and the major problem in management. Although individual infectious processes may have a predilection to involve the renal vasculature, glomeruli, interstitium, or collecting systems, a purely anatomic approach to the classification of infectious diseases affecting the kidney is rarely helpful because most infections may involve several different aspects of renal function. In this chapter, a microbiological classification of the organisms affecting the kidney is adopted. Although they are important causes of renal dysfunction in infectious diseases, urinary tract infections and hemolytic uremic syndrome (HUS) are not discussed in detail because they are considered separately in chapters XX and XX, respectively.

Urinary biomarkers of kidney diseases in HIV-infected children

A significant number of children infected with the human immunodeficiency virus 1 (HIV-1) virus all over the world are at risk of developing renal diseases that could have a significant impact on their treatment and quality of life. It is necessary to identify children undergoing the early stages of these renal diseases, as well as the potential renal toxicity that could be caused by antiretroviral drugs, in order to prevent the development of cardiovascular complications and chronic renal failure. This article describes the most common renal diseases seen in HIV-infected children, as well as the value and limitations of the clinical markers that are currently being used to monitor their renal function and histological damage in a noninvasive manner. In addition, we discuss the progress made during the last 10 years in the discovery and validation of new renal biomarkers for HIV-infected children and young adults. Although significant progress has been made during the early phases of the biomarkers discovery, more work remains to be done to validate the new biomarkers in a large number of patients. The future looks promising, however, the new knowledge needs to be integrated and validated in the context of the clinical environment where these children are living.

Renal transplantation in human immunodeficiency virus (HIV)-positive children

Renal transplantation is being performed in adult human immunodeficiency virus (HIV)-positive patients and increasingly in paediatric patients as well. A multidisciplinary team involving an infectious disease professional is required to assist with HIV viral-load monitoring and in choosing the most appropriate highly active antiretroviral therapy (HAART). Drug interactions complicate immunosuppressant therapy and require careful management. The acute rejection rates appear to be similar in adults to those in noninfective transplant recipients. Induction with basiliximab and calcineurin-based immunosuppression appears to be safe and effective in these recipients. Prophylaxis is advised for a variety of infections and may need life-long administration, especially in children. Organ shortage remains a significant problem, and kidneys from deceased HIV-positive donors have been used successfully in a small study population. Overall, with careful planning and close follow-up, successful renal transplantation for paediatric HIV-infected recipients is possible.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

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.

Renal abnormalities among HIV-infected, antiretroviral naive children, Harare, Zimbabwe: a cross-sectional study

BACKGROUND

Data on the prevalence of renal and urine abnormalities among HIV-infected children in Sub-Saharan Africa are limited. We set out to determine the prevalence of proteinuria; low estimated glomerular filtration rate (eGFR), urinary tract infection and associated factors among HIV-infected antiretroviral therapy (ART) naive children, aged 2-12 years, attending the paediatric HIV clinic at a tertiary hospital in Harare.

METHODS

Consecutive ART naive children attending the clinic between June and October 2009 were recruited. Detailed medical history was obtained and a complete physical examination was performed. Children were screened for urinary tract infection and for significant persistent proteinuria. Serum creatinine was used to estimate GFR using the modified Counahan-Barratt formula. The Student's t-test was used to analyse continuous variables and the chi-square or Fisher's exact test was used to analyse categorical data. Logistic regression was performed to assess the relationship between study factors and urine abnormalities, persistent proteinuria and the eGFR.

RESULTS

Two hundred and twenty children were enrolled into the study. The median age was 90 months (Q1=65.5; Q3=116.5). The prevalence of urinary tract infection was 9.5%. Escherichia coli was the predominant organism. There was uniform resistance to cotrimoxazole. Persistent proteinuria (urine protein to creatinine ratio greater than 0.2, a week apart) was found in 5% of the children. Seventy-five children (34.6%) had mild to moderate renal impairment shown by a low eGFR (30 to <90 ml/min/1.73 m2). Persistent proteinuria was more likely to be found in children who were wasted, weight-for-height (WHZ) z-score <-2 (p=0.0005). Children with WHO clinical stage 4 were more likely to have a low eGFR than children with less advanced stages (OR 2.68; CI 1.24-5.80). Urine abnormalities were more likely to be observed in children with WHO clinical stages 3 and 4 (OR 2.20; CI 1.06-4.60).

CONCLUSION

There is significant renal impairment among HIV-infected, ART naive children aged 2-12 years attending the outpatient paediatric HIV clinic at Harare Central Hospital. The abnormalities are more likely to occur in children with advanced HIV/AIDS. Screening for renal impairment and urinary tract infections in HIV-infected children before initiation of ART and regularly thereafter would be helpful in their management.

KEYWORDS

HIV, renal disease, persistent proteinuria, glomerular filtration rate, urinary tract infection.

Proteinuria in paediatric patients with human immunodeficiency virus infection

In human immunodeficiency virus (HIV)-infected people kidney disease is as an important cause of morbidity and mortality. Clinical features of kidney damage in HIV-infected patients range from asymptomatic microalbuminuria to nephrotic syndrome. The lack of specific clinical features despite the presence of heavy proteinuria may mask the renal involvement. Indeed, it is important in HIV patients to monitor renal function to early discover a possible kidney injury. After the introduction of antiretroviral therapy, mortality and morbidity associated to HIV-infection have shown a substantial reduction, although a variety of side effects for long-term use of highly active antiretroviral therapy, including renal toxicity, has emerged. Among more than 20 currently available antiretroviral agents, many of them can occasionally cause reversible or irreversible nephrotoxicity. At now, three antiretroviral agents, i.e., indinavir, atazanavir and tenofovir disoproxil fumarate have a well established association with direct nephrotoxicity. This review focuses on major causes of proteinuria and other pathological findings related to kidney disease in HIV-infected children and adolescents.

Chronic kidney disease associated with perinatal HIV infection in children and adolescents

BACKGROUND

This study describes the incidence, clinical and demographic characteristics, and spectrum of chronic kidney disease (CKD) in youths with perinatal HIV-1 infection.

METHODS

Retrospective analysis between May 1993 and December 2006 of subjects with renal disease followed in the Pediatric AIDS Clinical Trials Group 219/219C multicenter study examining the long-term consequences of perinatal HIV infection. Diagnosis confirmation was made utilizing a questionnaire mailed to research sites. Participants with CKD of other etiology than HIV were excluded. Outcome measures were biopsy-diagnosed CKD and, in the absence of biopsy, HIV-associated nephropathy (HIVAN) using established clinical criteria.

RESULTS

Questionnaires on 191 out of 2,102 participants identified 27 cases of CKD: 14 biopsy-diagnosed and 6 clinical cases of HIVAN, and 7 biopsy-diagnosed cases of immune complex-mediated kidney disease (lupus-like nephritis, 3; IgA nephropathy, 2; membranous nephropathy, 2). Incidence rates for CKD associated with HIV in pre-highly active antiretroviral therapy (HAART) (1993-1997) and HAART (1998-2002, 2003-2006) eras were 0.43, 2.84, and 2.79 events per 1,000 person years respectively. In multivariate analysis, black race and viral load ≥100,000 copies/mL (rate ratios 3.28 and 5.05, p ≤ 0.02) were associated with CKD.

CONCLUSIONS

A variety of immune complex-mediated glomerulonephritides and HIVAN occurs in this population. Black race and uncontrolled viral replication are risk factors for CKD associated with HIV.

HIV-associated nephropathy: a diagnosis in evolution

HIV-1 associated nephropathy (HIVAN) is a clinical and renal histological disease characterized by the presence of heavy proteinuria associated with focal segmental glomerulosclerosis and microcystic tubular dilatation. These renal lesions lead to renal enlargement and rapid progression to kidney failure. People from African ancestry show a unique susceptibility to develop HIVAN. The study by Wearne and colleagues, which includes the largest group of patients of African ancestry with HIVAN studied so far, describes a novel renal histological variant of HIVAN, and suggests that antiretroviral therapies improve the clinical outcome of all HIV-associated renal diseases. These findings, when interpreted in the context of recent advances in our understanding of the molecular pathogenesis and genetics of HIVAN, will facilitate the recognition of all clinical variants of HIVAN as well the planning of better screening, prevention, and treatment programs for all HIV nephropathies.

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.

Advances in our understanding of the pathogenesis of HIV-1 associated nephropathy in children

Childhood HIV-1 associated nephropathy (HIVAN) is a clinical and renal histological disease characterized by heavy proteinuria associated with focal and segmental glomerular sclerosis and/or mesangial hyperplasia in combination with microcystic tubular dilatation. These lesions lead to renal enlargement and rapid progression to kidney failure. Children of African ancestry have a unique susceptibility to developing HIVAN. It is estimated that approximately 300,000 HIV-infected children living in the sub-Saharan Africa could develop HIVAN if they do not receive appropriate antiretroviral therapy. This article discusses recent developments and controversies related to the pathogenesis of childhood HIVAN. The role of host genetic factors, including the newly identified variants in the APOL1 gene, is discussed in the context of previous studies that established the pathological paradigm for HIVAN, and our current understanding of the functional genomics analysis. Hopefully, these advances will provide new research opportunities to generate better treatments for children with HIVAN.

HIV-associated nephropathy in the setting of maximal virologic suppression

Human immunodeficiency virus (HIV)-associated nephropathy (HIVAN) is most frequently seen as a late manifestation in adult patients with a high viral load and low T-helper cell (CD4) counts. We report a case of HIVAN in a black Zimbabwean teenager in whom the disease activity was well suppressed for years following highly active antiretroviral therapy (HAART). Proteinuria was absent at 9 years of age when he presented with vertically transmitted HIV infection. Within a few months of HAART, the viral load became undetectable and CD4 count was normalised. Nephrotic range proteinuria, with preserved renal function, developed approximately 4 years later despite excellent HIV disease suppression. Renal biopsy showed non-collapsing focal segmental glomerular sclerosis changes compatible with HIVAN. Although the role of other unknown factors in the disease pathogenesis could not be totally excluded, this case demonstrates that HIVAN can still occur in HIV-infected children despite excellent HAART and that the disease manifestations and outcome may differ from those reported in previous studies.

Taking a hard look at the pathogenesis of childhood HIV-associated nephropathy

Childhood human immunodeficiency virus-associated nephropathy (HIVAN) is defined by the presence of proteinuria associated with mesangial hyperplasia and/or global-focal segmental glomerulosclerosis, in combination with the microcystic transformation of renal tubules. This review discusses the pathogenesis of childhood HIVAN and explores how the current pathological paradigm for HIVAN in adults can be applied to children. The Human Immunodeficiency Virus-1 (HIV-1) induces renal epithelial injury in African American children with a genetic susceptibility to develop HIVAN. The mechanism is not well understood, since renal epithelial cells harvested from children with HIVAN do not appear to be productively infected. Children with HIVAN show a renal up-regulation of heparan sulphate proteoglycans and a recruitment of circulating heparin-binding growth factors, chemokines, and mononuclear cells. Macrophages appear to establish a renal HIV-reservoir and transfer viral particles to renal epithelial cells. All of these changes seem to trigger an aberrant and persistent renal epithelial proliferative response. The paradigm that viral products produced by infected renal epithelial cells per se induce the proliferation of these cells is not supported by data available in children with HIVAN. More research is needed to elucidate how HIV-1 induces renal epithelial injury and proliferation in HIV-infected children.