Clinicopathologic Study of Sickle Cell-associated Kidney Disease: A Nigerian Experience.

BACKGROUND: Improvements in sickle cell disease (SCD) care have resulted in the survival of many patients into adulthood, although this is accompanied by the increased incidence of end-organ damage, including chronic kidney disease (CKD). OBJECTIVES: This study assessed the prevalence, pattern and predictors of renal dysfunction in SCD patients and investigated the associated renal histopathologic changes. METHODS: We evaluated 105 patients with SCD, for proteinuria, estimated glomerular filtration rate (eGFR), and tubular dysfunction. Renal biopsy was conducted on 22 patients who qualified. Data were analysed using SPSS package version 23. RESULTS: Thirty-seven (35.2%) of the 105 patients had CKD, as defined by an eGFR of 60 ml/min/1.73 m2 and/or proteinuria. The fractional excretion of potassium (FEK) was elevated in all patients, whereas the fractional excretion of sodium (FENa) was elevated in 98.1%. Glomerular filtration rate was negatively correlated with irreversible percentage sickle cell count (r = -0.616, P = 0.0001), FEK (r = -0.448, P = 0.0001) and FENa (r = -0.336, P = 0.004). Age, irreversible percentage sickle cell count, haemoglobin levels and FENa were the major predictors of CKD. The histological pattern in the 22 patients who had biopsies was consistent with mesangioproliferative glomerulonephritis 11 (50%), minimal change disease 6 (27.3%), focal segmental glomerulosclerosis 3 (13.6%) and interstitial nephritis 2 (9.1%). CONCLUSIONS: CKD was prevalent in SCD patients, and it was characterised by tubular dysfunction and mesangioproliferative glomerulonephritis. The main predictors of CKD were increased age, severity of vaso-occlusive crisis, worsening anaemia and tubular dysfunction.

Comparative Evaluation of Prevalence, Risk Factors, and Pathologic Features of Kidney Disease in Highly Active Antiretroviral Therapy-Naive and Highly Active Antiretroviral Therapy-Experienced Patients at a Tertiary Health Facility in Maiduguri, Northeastern Nigeria.

Infection of the kidneys by human immunodeficiency virus (HIV) is known to cause kidney disease. HIV-associated nephropathy occurs with variable prevalence rates in various communities and is found to be higher among sub-Saharan Africans. The disease has not been studied in Northeastern Nigeria. This study was aimed at comparing the prevalence, clinical and histo-pathologic features of kidney disease among highly active antiretroviral therapy (HAART)-experienced and HAART-naive patients in northeastern Nigeria. Four hundred HIV-infected (200 HAART-experienced and 200 HAART-naïve) patients were recruited consecutively from the ART clinic. Their socio-demographic and laboratory data including CD4+ cell counts and viral loads were obtained and documented. Out of the 200 study participants in the HAART-experienced arm, 21 (10.5%) had kidney disease whereas 61 (30.5%) participants in the HAART-naïve group had kidney disease. Their mean ages were 41.43 ± 11.04 years and 37.42 ± 9.96 years in the HAART-experienced and HAART-naïve groups, respectively. The mean serum creatinine (SCr), CD4+ cell counts, and viral load were 185.67 ± 221.80 µmol/L, 493.26 ± 241.97/mm3, and 8,856.79 ± 19,747.11/mL in the HAART-experienced group, respectively. In the HAART-naïve group, the mean SCr, CD4+ cell count, and viral load were 141.88 ± 130.56 µmol/L, 270.00 ± 154.65 cells/mm3, and 139,217.70 ± 12,598.50/mL. Focal segmental glomerulosclerosis (FSGS) was the most common histologic diagnosis in 64.7% of kidney biopsies. Risk factors for chronic kidney disease among the study population included age, low weight and body mass index, high human immunodeficiency virus (HIV)-1 viral load, low CD4+ cell counts, low hemoglobin (Hb), and proteinuria. The prevalence of kidney disease is higher among HAART-naïve HIV-infected patients than in patients who are HAART-experienced patients. Factors associated with development of kidney disease included advanced age, low CD4+ cell counts, high viral load, proteinuria, and HAART-naivety. FSGS is the most common histologic diagnosis in our study population.

Burden and etiopathogenesis of acute kidney injury in the tropics.

Acute kidney injury (AKI) is prevalent and is associated with high morbidity and mortality globally. The epidemiology differs remarkably between developing and developed economies. Infections, diarrheal illnesses, obstetric causes and nephrotoxins are very rampant in the tropics. Even though the etiologies are different, the final common pathway in the pathogenesis is similar - tubular damage or necrosis, tubular blockage, and back leak of glomerular filtrate. The mechanism of AKI in infections could be through ischemic insult consequent to hypovolemia and/or hemoglobinuria, as seen in malaria and viral hemorrhagic fevers, interstitial inflammation, or nephrotoxicity. On the contrary, the mechanism of nephrotoxin-induced AKI includes direct toxic effect on the renal tubules, intratubular precipitation of substances like djenkolic and oxalic acids (crystalluria) as well as intratubular obstruction and AKI. Toxicity could also be indirect by interacting with the pharmacokinetic profile of other coadministered medications. Bites and envenomation as well as obstetric complications also induce AKI through hypovolemia, interstitial nephritis, and other unclear mechanisms in eclampsia and preeclampsia. Outcome is variable and dependent on etiology. Prognosis appears to be significantly better in hypovolemic or prerenal and/or obstructive AKI compared to intrarenal or intrinsic AKI.