The evolution of our knowledge of HIV-associated kidney disease in Africa

HIV and Associated TB: A Lethal Association for Kidney Health?

Human immunodeficiency virus (HIV) and tuberculosis (TB) are the leading infectious causes of death globally. The combined brunt of these diseases is experienced mainly in low-income and lower-middle-income countries. HIV/TB have devastating effects on the kidneys, leading to accelerated decline of kidney function as well as mortality. Managing the triad of TB/HIV and kidney disease is challenging. We discuss the epidemiology of HIV/TB coinfection and the kidney and the key mechanisms of kidney disease including genetic susceptibility. The clinical presentation and pathology, as well as the challenges of diagnosing CKD in these patients, also are discussed. The strategies to prevent and manage HIV/TB-related kidney disease such as proper assessment, avoiding nephrotoxic regimens, drug dose adjustments, kidney function monitoring, avoidance of drug-drug interactions, and other interventions are explored. We also briefly discuss the complexities around HIV/TB patients on dialysis and kidney transplantation. HIV/TB coinfection presents an increased risk for kidney-related morbidity and mortality; patients with this triad need to be given special consideration for future research and management.

Predictors and Prognosis of HIV-Associated Nephropathy on Kidney Biopsy in South Africa

Introduction

South Africa has the highest prevalence of HIV in the world. The epidemiology of kidney disease among people with HIV infections is well-described in the United States. However, there are limited data coming from South Africa, particularly that involve kidney biopsies. The purpose of this study was to determine what, if any, patient factors are predictive of HIV-associated nephropathy (HIVAN) on kidney biopsy in a South African kidney biopsy cohort.

Methods

This study prospectively collected data of all patients infected with HIV referred to the Groote Schuur Hospital (GSH) renal unit for a kidney biopsy from 2002 to 2018.

Results

There were 419 patients included in the study. Mean age was 36.5 years (SD, 9.4); 219 (52.3%) were women; and all were black. Seventy-nine patients (18.9%) were on dialysis at the time of biopsy; the mean estimated glomerular filtration rate among the remainder was 41.4 ml/min per 1.73 m² (SD, 39.2). Only 163 patients (47.1%) were known to be taking antiretroviral therapy (ART) at the time of biopsy. There were 246 (58.7%) cases of HIVAN detected, and they were comparable on age, sex, kidney function, and kidney size to those with kidney disease of other causes but were less likely to be taking ART (P < 0.001). Biopsy confirmed HIVAN was associated with mortality (adjusted hazard ratio, 1.77; 95% confidence interval [CI]: 1.07–2.91; P = 0.025), and the use of ART at biopsy was protective (adjusted hazard ratio, 0.52; 95% CI, 0.32–0.84, P = 0.008). The proportion of HIVAN on biopsy decreased and the proportion taking ART increased from 2002 to 2018 (P for trend for both < 0.001).

Conclusion

In summary, HIVAN was the most common etiology of kidney disease in this biopsy cohort from South Africa; however, the proportion with biopsy-proven HIVAN declined over time, perhaps in the setting of greater ART availability.

Diagnostic Challenges of Acute Kidney Injury in Asia

Early diagnosis of acute kidney injury (AKI) is an important step to improve AKI outcome. In Asia, several distinct conditions of this region such as environment (tropical climate), socioeconomic status (high-resource and low-resource settings), process of care (shortage of nephrologists), exposure factors (specific tropical infections such as leptospirosis, malaria, dengue), and inherent factor (aging) make the diagnosis of AKI in Asia more challenging than in other parts of the world. To improve the diagnosis of AKI, novel tools such as clinical risk scores, AKI alert systems, and telemedicine should be implemented into current clinical practice.

Nephrology in South Africa: Not Yet ubuntu

Background

South Africa (SA) is an upper middle-income country with a human immunodeficiency virus (HIV) epidemic, an accelerated burden of non-communicable diseases, and a concurrent epidemic of tuberculosis. These con-ditions overwhelm a health system struggling under the pressure of restricted resources, including an insufficient workforce. Private practice has become more involved in the care of patients in the country but serves mainly those who are members of a Medical Aid. These Medical Aids will usually cover up to 100% of the costs for management of chronic kidney disease (CKD).

Summary

There are currently 2.3 nephrologists per million individuals, which is far lower than the global average and grossly inadequate to meet the nephrology care needs in SA. Covert chronic dialysis rationing has occurred in the public sector since the 1960s. However, the lack of formality triggered the formation of explicit rationing guidelines in one province. These guidelines have been ethically endorsed but not embraced nationally. The demand for hemodialysis (HD) has led some provinces to practicing "PD-First" programs. SA remains one of only 12 countries within Africa that perform renal transplantation, and it is the only country in Africa that relies on deceased donation for the majority of its transplants. The first kidney transplant in SA took place at the University of the Witwatersrand, Johannesburg, in 1966 and the first dialysis was performed by a general practitioner working in a town close to Johannesburg in 1957. The University of Cape Town successfully pioneered the transplantation of kidneys from HIV-positive donors to positive recipients. SA was the second country in the world to form a National Kidney Foundation as well as a renal society. Nephrology training is in place and incorporates master's and PhD programs in nephrology. Despite the numerous challenges, SA nephrologists have been among the leading researchers in nephrology from the African continent.

HIV-Associated Nephropathy in Africa: Pathology, Clinical Presentation and Strategy for Prevention

The human immunodeficiency virus (HIV) infection can lead to progressive decline in renal function known as HIV-associated nephropathy (HIVAN). Importantly, individuals of African ancestry are more at risk of developing HIVAN than their European descent counterparts. An in-depth search on Google Scholar, Medline and PubMed was conducted using the terms "HIVAN" and "pathology and clinical presentation", in addition to "prevalence and risk factors for HIVAN", with special emphasis on African countries for any articles published between 1990 and 2017. HIVAN is characterized by progressive acute renal failure, proteinuria and enlarged kidneys. A renal biopsy is necessary to establish definitive diagnosis. Risk factors are male gender, low CD4 counts, high viral load and long use of combined antiretroviral medication (cART). There is a wide geographical variation in the prevalence of HIVAN as it ranges from 4.7% to 38% worldwide and little published literature is available about its prevalence in African nations. Microalbuminuria is a common finding in African populations and is significantly associated with severity of HIV disease progression and CD4 count less than 350 cells/µL. Other clinical presentations in African populations include acute kidney injury (AKI), nephrotic syndrome and chronic kidney disease. The main HIV-associated renal pathological lesions were focal segmental glomerulosclerosis, mainly the collapsing form, acute interstitial nephritis (AIN), and immune complex-mediated glomerulonephritis (ICGN). HIV infection-induced transcriptional program in renal tubular epithelial cells as well as genetic factors is incriminated in the pathogenesis of HIVAN. This narrative review discusses the prevalence, presentation, pathogenesis and the management of HIVAN in Africa. In low resource setting countries in Africa, dealing with HIV complications like HIVAN may add more of a burden on the health system (particularly renal units) than HIV medication itself. Therefore, the obvious recommendation is early use of cART in order to decrease risk factors that lead to HIVAN.

Acute Kidney Injury Recognition in Low- and Middle-Income Countries

Acute kidney injury (AKI) is increasingly common around the world. Because of the low availability of effective therapies and resource limitations, early preventive and therapeutic measures are essential to decrease morbidity, mortality, and cost. Timely recognition and diagnosis of AKI requires a heightened degree of suspicion in the appropriate clinical and environmental context. In low- and middle-income countries (LMICs), early detection is impaired by limited resources and low awareness. In this article, we report the consensus recommendations of the 18th Acute Dialysis Quality Initiative meeting in Hyderabad, India, on how to improve recognition of AKI. We expect these recommendations will lead to an earlier and more accurate diagnosis of AKI, and improved research to promote a better understanding of the epidemiology, etiology, and histopathology of AKI in LMICs.

Tubulointerstitial nephropathies in HIV-infected patients over the past 15 years: a clinico-pathological study

BACKGROUND AND OBJECTIVES

The therapy and outcome of HIV infection have dramatically changed over the last 15 years, resulting in a change in renal complications. This study analyzed the characteristics of HIV-infected patients and biopsy-proven tubulointerstitial nephropathies to define disease patterns and therapeutic implications.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A clinico-pathologic retrospective study of 59 consecutive renal biopsies showing predominant tubular and/or interstitial lesions in HIV-infected patients referred to the nephrology department between 1995 and 2011 was performed. HIV-associated nephropathy and vascular diseases were excluded from the study.

RESULTS

Tubulointerstitial nephropathies accounted for 26.6% of 222 native renal biopsies performed in HIV-infected patients. Two pathologic groups were analyzed, tubulopathy and interstitial nephritis, which represented 49% and 51% of tubulointerstitial nephropathies, respectively. Most patients presented with AKI (76.3%) and high-grade proteinuria (57.7%). Drug-related nephrotoxicity was the leading cause (52.5%). Alternative etiologies included infections (15.2%), dysimmune disorders (8.5%), malignancies (3.4%), and chronic (10.2%) and acute (10.2%) tubulointerstitial nephropathies of undetermined origin. Tubulopathy was strongly associated with antiretroviral drug toxicity (75.9%) and mostly caused by tenofovir (55.2%), which was associated with proximal tubular dysfunction (87.5%), overt Fanconi's syndrome (37.5%), and nephrogenic diabetes insipidus (12.5%). Interstitial nephritis was associated with a broader spectrum of pathologic lesions and etiologies.

CONCLUSIONS

In this series, tubulointerstitial nephropathies accounted for 26.6% of renal diseases in HIV-infected patients. Considering the therapeutic implications of diagnoses of drug toxicity, infection, and dysimmune syndromes, this study underscores the importance of monitoring renal parameters in HIV-infected patients and points to the relevance of kidney biopsy to allow an accurate diagnosis.