Granulomatous interstitial nephritis on renal biopsy in human immunodeficiency virus positive patients: Prevalence and causes in Cape Town, South Africa.

South Africa continues to be burdened by human immunodeficiency virus (HIV) and tuberculosis (TB). In Cape Town, the epidemic of HIV-TB co-infection is as high as 70%. Granulomatous interstitial nephritis (GIN) has increased in frequency on renal biopsy. This study aimed to determine GIN prevalence and causes in HIV-positive patients as well as renal outcomes, patient survival and associated factors. This observational cohort study reviewed HIV-positive renal biopsies for GIN from 2005 to 2012. Causes of GIN (medications, TB, fungal and other), and baseline characteristics were analysed. A comparison of baseline data, renal function and survival was made between GIN and non-GIN cohorts. There were 45/316 biopsies demonstrating GIN. TB was the likely cause of GIN in 27 (60%) and 9 (20%) were due to a drug. Low estimated glomerular filtration rate was a statistically significant factor associated with mortality in both GIN (P = 0.045) and non-GIN cohorts (P < 0.000). In the GIN group, there were 12 (26.7%) deaths. Mortality for all patients was greatest in the first 6 months (P = 0.057). TB co-infection in both cohorts was associated with a higher mortality. The multivariate logistic regression demonstrated that a higher urine protein/creatinine ratio (uPCR) and lower estimated glomerular filtration rate were statistically associated with death. GIN is common in HIV-positive renal biopsies in Cape Town. TB-GIN was the commonest cause and associated with a high early mortality. GIN should be considered in HIV-positive patients with acute kidney injury, its presence conveys a survival benefit. There is a need for improved diagnostic accuracy and treatment strategies of TB-GIN.

The Evolving Spectrum of Kidney Histology in HIV-Positive Patients in South Africa.

Introduction: Sub-Saharan Africa remains challenged by the highest burden of human immunodeficiency virus (HIV), an epidemic of tuberculosis (TB), and increasing number of people with HIV (PWH) on antiretroviral therapy (ART), all of which may result in kidney injury. Methods: This observational cohort study describes the spectrum of kidney disease in PWH in South Africa, between 2005 and 2020. Kidney biopsies were analyzed in 4 time periods as follows: early ART rollout (2005-2009), tenofovir disoproxil (TDF) introduction (2010-2012), TDF-based fixed dose combination (2013-2015), and ART at HIV diagnosis (2016-2020). Logistic regression was used to identify factors associated with HIV-associated nephropathy or focal segmental glomerulosclerosis (HIVAN/FSGS) and tubulointerstitial disease (TID). Results: We included 671 participants (median age 36, interquartile range, 21-44 years; 49% female; median CD4 cell count 162 [interquartile range, 63-345] cells/mm3). Over time, ART (31%-65%, P < 0.001), rate of HIV suppression (20%-43%, P < 0.001), nonelective biopsies (53%-72%, P < 0.001), and creatinine at biopsy (242-449 µmol/l, P < 0.001) increased. A decrease in HIVAN (45%-29% P < 0.001) was accompanied by an increase in TID (13%-33%, P < 0.001). Granulomatous interstitial nephritis accounted for 48% of TID, mostly because of TB. Exposure to TDF was strongly associated with TID (adjusted odds ratio 2.99, 95% confidence interval 1.89-4.73 P < 0.001). Conclusion: As ART programs intensified and increasingly used TDF, the spectrum of kidney histology in PWH evolved from a predominance of HIVAN in the early ART era to TID in recent times. The increase in TID is likely due to multiple exposures that include TB, sepsis, and TDF as well as other insults.

Cardiac amyloidosis-A review of current literature for the practicing physician.

The amyloidoses are a family of diseases in which misfolded precursor proteins aggregate to form amyloid and deposit in body tissues. A very serious yet underrecognized form of this disease is cardiac amyloidosis, in which amyloid deposits into the extracellular space of the myocardium, resulting in thickening and stiffening of ventricular walls with resultant heart failure and conductive dysfunction. This review provides a discussion of the pathogenesis and clinical presentation of cardiac amyloidosis subtypes, as well as an up-to-date approach to diagnosis and treatment. Significant progress has been made in recent years regarding diagnosis and treatment of this condition, but prognosis remains heavily reliant on early detection of the disease. Two types of precursor protein are responsible for most cardiac amyloidosis cases: transthyretin amyloid, and immunoglobulin-derived light chain amyloid. An early diagnosis of cardiac amyloidosis can allow for novel treatment modalities to be initiated with the potential to improve prognosis.

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.

Kidney disease in Africans with HIV and tuberculosis.

OBJECTIVE: To describe the spectrum of kidney disease in African patients with HIV and tuberculosis (TB). METHODS: We used data from three cohorts: consecutive patients with HIV/TB in South London (UK, 2004-2016; n = 95), consecutive patients with HIV/TB who underwent kidney biopsy in Cape Town (South Africa, 2014-2017; n = 70), and consecutive patients found to have HIV/TB on autopsy in Abidjan (Cote d'Ivoire, 1991; n = 100). Acute kidney injury (AKI) was ascertained using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. In the Cape Town cohort, predictors of recovery of kidney function at 6 months were assessed using Cox regression. RESULTS: In the London cohort, the incidence of moderate/severe AKI at 12 months was 15.1 (95% CI 8.6-26.5) per 100 person-years, and the prevalence of chronic and end-stage kidney disease (ESKD) 13.7 and 5.7%, respectively. HIV-associated nephropathy (HIVAN) was diagnosed in 6% of patients in London, and in 6% of autopsy cases in Abidjan. Evidence of renal TB was present in 60% of autopsies in Abidjan and 61% of kidney biopsies in Cape Town. HIVAN and acute tubular necrosis (ATN) were also common biopsy findings in Cape Town. In Cape Town, 40 patients were dialyzed, of whom 28 (70%) were able to successfully discontinue renal replacement therapy. Antiretroviral therapy status, CD4 cell count, estimated glomerular filtration rate (eGFR) at biopsy and renal histology, other than ATN, were not predictive of eGFR recovery. CONCLUSION: Kidney disease was common in Africans with HIV/TB. Monitoring of kidney function, and provision of acute dialysis to those with severe kidney failure, is warranted.