Proximal renal tubular function in HIV-infected children on tenofovir disoproxil fumarate for treatment of HIV infection at two tertiary hospitals in Harare, Zimbabwe

Abstract

BackgroundRenal abnormalities in HIV infected children may be due to the HIV infection or treatment among other factors. Tenofovir disoproxil fumarate (TDF) is associated with proximal renal tubular dysfunction, proteinuria and decrease in glomerular function. Studies in developed countries have shown variable prevalence of proximal renal tubular dysfunction in children on TDF. There are no known studies in developing countries, including Zimbabwe, documenting the proximal tubular function in HIV infected children on TDF. The aim of this study was to assess renal and proximal renal tubular function in HIV infected children receiving TDF and determine factors associated with proximal tubular dysfunction. MethodsA descriptive cross-sectional study was conducted in HIV infected patients below 18 years of age attending outpatient clinics at two tertiary hospitals in Harare, who received a TDFcontaining antiretroviral regimen for at least six months. Dipstick protein and glucose, serum and urine phosphate and creatinine levels were measured. Fractional excretion of phosphate was calculated. Estimated glomerular filtration rate (eGFR) was calculated using the Schwartz formula. Tubular dysfunction was defined by at least two of the following characteristics: normoglycaemic glycosuria, hypophosphatemia and fractional excretion of phosphate > 18%.

Prevalence of chronic kidney disease among young people living with HIV in Sub Saharan Africa: A systematic review and meta-analysis

“…The most common biomarker used for CKD diagnosis was serum creatinine measured by the enzymatic method. Estimated GFR (eGFR) was used in 13 studies alone and in combination with markers of kidney damage (6, 33, 44–47, 51–53, 55–58). Five studies used an eGFR cut-off of <60ml/min/1.73m 2 (44–46, 55, 57), two used this cutoff alone without any marker of kidney damage (45, 57) and six used a cut-off of <90ml/min/1.73m 2 (6, 33, 47, 51, 53, 58).…”

“…However, only four studies fulfilled the chronicity criteria; three studies repeated the tests after more than 3 months (47, 51, 55), and one study repeated the tests after only one month (49). Three studies used a cut-off of <90 ml/min/1.73m 2 which does not fit the KDIGO definition and tended to overestimate the CKD prevalence (6, 53, 54). Other studies used ranges such as 60-90 or 30-60 ml/min/1.73m 2 potentially underestimating the CKD prevalence (45, 51).…”

Bone outcomes in virally suppressed youth with HIV switching to tenofovir disoproxil fumarate

“…A cross-sectional study of Zimbabwean children and adolescents < 18 years and on TDF found hypophosphataemia, proteinuria and a decreased eGFR of < 90 mL/min per 1.73 m² in 11.1%, 32.8% and 35.9%, respectively. 47 Proteinuria and a lower eGFR were associated with concomitant protease inhibitor (PI) use. 47 It is difficult to compare studies, as participants in the Zimbabwean study were younger with a shorter duration of ART, and VL was not evaluated because of cost restraints.…”

“… 47 Proteinuria and a lower eGFR were associated with concomitant protease inhibitor (PI) use. 47 It is difficult to compare studies, as participants in the Zimbabwean study were younger with a shorter duration of ART, and VL was not evaluated because of cost restraints. We found no evidence of hypophosphataemia, phosphaturia, proteinuria or renal impairment 24 weeks after the switch to TDF-containing ART.…”

Burden of Paediatric Kidney Diseases in a Tertiary Care Hospital in Harare, Zimbabwe

“…16 Reduction in estimated glomerular filtration rate (eGFR) < 90 ml/min/1.73 m 2 and proteinuria was evident in 35.9% and 32.8% of children, respectively for those on ART. 17…”