Browsing by Author "Naicker, Saraladevi"

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    Data Set : Prevalence, characterization and response to chronic kidney disease in an urban and rural setting in South Africa
    (2016-11-18) Naicker, Saraladevi; Fabian, June; Jaya A George; Harriet R Etheredge; Manuel van Deventer; Robert Kalyesubula; Alisha N Wade; Laurie A Tomlinson; Stephen Tollman
    Globally, chronic kidney disease (CKD) is an emerging public health challenge but accurate data on its true prevalence are scarce, particularly in poorly resourced regions such as sub-Saharan Africa (SSA). Limited funding for population-based studies, poor laboratory infrastructure and the absence of a validated estimating equation for kidney function in Africans are contributing factors. Consequently, most available studies used to estimate population prevalence are hospital-based, with small samples of participants who are at high risk for kidney disease. While serum creatinine is most commonly used to estimate glomerular filtration, there is considerable potential bias in the measurement of creatinine that might lead to inaccurate estimates of kidney disease at individual and population level. To address this, the Laboratory Working Group of the National Kidney Disease Education Program published recommendations in 2006 to standardize the laboratory measurement of creatinine. The primary objective of this review was to appraise implementation of these recommendations in studies conducted in SSA after 2006. Secondary objectives were to assess bias relating to choice of estimating equations for assessing glomerular function in Africans and to evaluate use of recommended diagnostic criteria for CKD. This study was registered with Prospero (CRD42017068151), and using PubMed, African Journals Online and Web of Science, 5845 abstracts were reviewed and 252 full-text articles included for narrative analysis. Overall, two-thirds of studies did not report laboratory methods for creatinine measurement and just over 80% did not report whether their creatinine measurement was isotope dilution mass spectroscopy (IDMS) traceable. For those reporting a method, Jaffe was the most common (93%). The four-variable Modification of Diet in Renal Disease (4-v MDRD) equation was most frequently used (42%), followed by the CKD Epidemiology Collaboration (CKD-EPI) equation for creatinine (26%). For the 4-v MDRD equation and CKD-EPI equations, respectively, one-third to one half of studies clarified use of the coefficient for African-American (AA) ethnicity. When reporting CKD prevalence, <15% of studies fulfilled Kidney Disease: Improving Global Outcomes criteria and even fewer used a population-based sample. Six studies compared performance of estimating equations to measured glomerular filtration rate (GFR) demonstrating that coefficients for AA ethnicity used in the 4-v MDRD and the CKD-EPI equations overestimated GFR in Africans. To improve on reporting in future studies, we propose an 'easy to use' checklist that will standardize reporting of kidney function and improve the quality of studies in the region. This research contributes some understanding of the factors requiring attention to ensure accurate assessment of the burden of kidney disease in SSA. Many of these factors are difficult to address and extend beyond individual researchers to health systems and governmental policy, but understanding the burden of kidney disease is a critical first step to informing an integrated public health response that would provide appropriate screening, prevention and management of kidney disease in countries from SSA. This is particularly relevant as CKD is a common pathway in both infectious and non-communicable diseases, and multimorbidity is now commonplace, and even more so when those living with severe kidney disease have limited or no access to renal replacement therapy.
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    Dataset from: Clinicopathological correlation of kidney disease in HIV infection pre- and post- ART rollout: VERSION 2
    (2022-04-14) Diana, Nina Elisabeth; Davies, Malcolm; Mosiane, Pulane; Vermeulen, Alda; Naicker, Saraladevi
    Data note Methods Ethics approval for this study was granted in writing by the Human Research Ethics Committee (Medical) of the University of the Witwatersrand, Johannesburg, South Africa (clearance certificate numbers M1511104, M121184, M120874). This approval permitted a record review of all HIV-positive patients who underwent a kidney biopsy at two tertiary hospitals in Johannesburg within the defined study period. Informed consent for this retrospective record review was waived. Data from included patients was anonymised prior to statistical analysis. Renal biopsies performed at these two tertiary hospitals, on HIV-positive individuals, from January 1989 to December 2014 were retrospectively analysed. Demographic data (age, sex and race), clinical parameters (CD4 count, HIV viral load, serum creatinine and urine protein creatinine ratio), indication for biopsy and renal histological pattern was recorded at time of kidney biopsy. The estimated glomerular filtration rate (eGFR) was calculated according to the CKD-EPI creatinine equation without ethnicity correction. ART rollout began in April 2004 in South Africa. Patients were divided into 2 groups - those who were biopsied pre-ART rollout and those biopsied post-ART rollout. These two groups were compared with respect to the above parameters. In a subgroup of the patients biopsied between 2004 and 2014, additional data laboratory parameters (serum haemoglobin, serum albumin, serial serum creatinine and eGFR) and ART use (at time of biopsy) were recorded. All renal biopsies were processed according to standard techniques for light microscopy, immunofluorescence and electron microscopy. All biopsies were reviewed by the National Health Laboratory Service histopathology team who were aware of the HIV status of the patient at time of biopsy. Histological diagnoses were tabulated using the 2018 Kidney Disease Improving Global Outcomes (KDIGO) Controversies Conference guidelines. As per this guideline FSGS (NOS) in the setting of HIV describes all non-collapsing forms of FSGS. Those ICGN with no identifiable comparative etiology other than HIV were categorized as uncharacterized ICGN with no etiology other than HIV. The biopsies with multiple diagnoses were assigned its major clinical-pathological diagnosis for the purposes of analysis. All data was collected by Dr Nina Diana and Dr Alda Vermeulen from paper based patient hospital records and the electronic hospital laboratory system. All data was checked twice to ensure accuracy. Each patient was allocated a study number and data anonymised prior to entry into Microsoft Excel. Shapiro Wilk W testing and visual inspection of the histogram plot indicated non-parametric distribution of baseline characteristics of the cohort; accordingly, central and dispersal measurements were described using the median and interquartile range (IQR), and the Kruskal Wallis ANOVA and Mann-Whitney U tests were used for comparative analyses. Kidney survival, defined by an eGFR above threshold for consideration for dialysis initiation in these institutions (15mL/min/1.73m²), censored for patient default with preserved function, was fitted for patients in the subgroup using the Kaplan Meyer method; histological diagnoses were compared using Log-rank testing.
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    Influence of vitamin D receptor polymorphisms on biochemical markers of mineral bone disorders in South African patients with chronic kidney disease
    (2018-02) Waziri, Bala; Dix-Peek, Therese; Dickens, Caroline; Duarte, Raquel; Naicker, Saraladevi
    Background: It remains unclear whether genetic factors may explain the reported variation in the levels of biochemical markers of chronic kidney disease mineral and bone disorders (CKD- MBD) across ethnic groups. Therefore, the aim of this study was to examine the influence of vitamin D receptor (VDR) polymorphisms on secondary hyperparathyroidism and its association with vitamin D levels in black and white South African study participants. Methods: This was a cross sectional study involving 272 CKD stage 3- 5D patients and 90 healthy controls. The four major VDR polymorphisms (Bsm 1, Fok 1, Taq 1, and Apa1) were genotyped using the polymerase chain reaction- restriction fragment length polymorphism (PCR –RFLP) method. In addition, biochemical markers of CKD-MBD were measured to determine their associations with the four VDR polymorphisms. Results: With the exception of Taq I polymorphism, the distribution of the VDR polymorphisms differed significantly between blacks and whites. In hemodialysis patients, the Bb genotype was significantly associated with moderate secondary hyperparathyroidism (OR, 3.88; 95 CI 1.13–13.25, p = 0.03) and severe hyperparathyroidism (OR, 2.54; 95 CI 1.08–5.96, p = 0.03). This was consistent with the observed higher levels of median parathyroid hormone, fibroblast growth factor 23 and mean phosphate in patients with Bb genotype. This candidate risk genotype (Bb) was over represented in blacks compared to whites (71.0% versus 55.6%, p < 0.0001). In an unadjusted regression model, FokFf genotype was found to be significantly associated with the risk of developing severe vitamin D deficiency < 15 ng/ml (OR, 1.89; 95 CI 1.17–3.07, p = 0.01). Conclusion: The VDR Bb genotype is an independent predictor of developing secondary hyperparathyroidism in patients with end stage kidney disease. In addition, study participants with FokFf genotype are at increased of developing severe 25 -hydroxyvitamin D [25(OH)D] deficiency.