Evaluation of renal function in sickle cell disease patients in Brazil

Abstract

The objective of this study was to investigate renal function in a cohort of 98 patients with sickle cell disease (SCD) followed up at a tertiary hospital in Brazil. Clinical and laboratory characteristics at the time of the most recent medical examination were analyzed. Renal function was evaluated by the estimation of glomerular filtration rate (GFR) by the criteria of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI). We compared patients with normal GFR to patients with decreased GFR (<60 mL·min−1·(1.73 m2)−1) and hyperfiltration (>120 mL·min−1·(1.73 m2)−1). Comparison between patients according to the use of hydroxyurea and comparison of clinical and laboratory parameters according to GFR were also carried out. Average patient age was 33.8 ± 13.3 years (range 19-67 years), and 57 (58.1%) patients were females. The comparison of patients according to GFR showed that patients with decreased GFR (<60 mL·min−1·(1.73 m2)−1) were older, had lower levels of hematocrit, hemoglobin and platelets and higher levels of urea and creatinine. Independent risk factors for decreased GFR were advanced age (OR = 21.6, P < 0.0001) and anemia (OR = 39.6, P < 0.0001). Patients with glomerular hyperfiltration tended to be younger, had higher levels of hematocrit, hemoglobin and platelets and lower levels of urea and creatinine, with less frequent urinary abnormalities. Hydroxyurea, at the dosage of 500-1000 mg/day, was being administered to 28.5% of the patients, and there was no significant difference regarding renal function between the two groups. Further studies are required to establish the best therapeutic approach to renal abnormalities in SCD.

Renal Tubular Dysfunction in Sickle Cell Disease

“…In a cohort of 85 children with SCD, 76% had glomerular hyperfiltration [15]. In a recent study performed in our region, hyperfiltration was found in 53% of SCD patients [12], which was higher than the found in the present study.…”

“…In the present study, there was no difference in the mean glomerular filtration rate (GFR) between patients and controls, however there was a significant number of SCD patients with decreased GFR (<60mL/min/1.73m 2 ), which was found in 11.5% of cases, which is higher than the previous found in another study in our region, which found a prevalence of GFR<60mL/min/1.73m 2 in 5.1% of SCD patients [12]. We have identified 3 patients with renal failure, probably corresponding to chronic kidney disease, and all these 3 patients had concentration and acidification deficit.…”

Socioeconomic and demographic characteristics of sickle cell disease patients from a low-income region of northeastern Brazil

“…It was also found that approximately half of the patients (43.2%) were taking hydroxyurea. This percentage is higher than that reported by other studies conducted in Brazil 18,22 and the USA, 23,24 and demonstrates good adherence of the patients to treatment and the healthcare team's confidence in the efficacy of the medicine. However, only 11% of under 5-year-old children were taking hydroxyurea, which seems to reflect the concerns about the overall safety of this medicine, mainly in very young children.…”

Determining Glomerular Filtration Rate in Homozygous Sickle Cell Disease: Utility of Serum Creatinine Based Estimating Equations

“…[10],all of which would lead to distorted levels of serum creatinine and creatinine clearance measurements in urine as well as lead to invalidating current methods to determine renal dysfunction, these methods are being widely used in assessing kidney function in SCD [19], [20], [21], [22], [23], [24], [25]. These studies have included children and adults and have utilized various predictive equations such as MDRD, CG, Schwartz, and CKD-EPI to estimate GFR as a marker of renal function in these studies.…”