Renal Function in Children Suffering from Sickle Cell Disease: Challenge of Early Detection in Highly Resource-Scarce Settings

et al. (2014) Renal Function in Children Suffering from Sickle Cell Disease: Challenge of Early Detection in Highly Resource-Scarce Settings. PLoS ONE 9(5): e96561. doi:10.1371/journal.pone.0096561 Renal Function in Children Suffering from Sickle Cell Disease: Challenge of Early Detection in Highly Resource- Scarce Settings Michel Ntetani Aloni 0 Rene Makwala Ngiyulu 0 Jean-Lambert Gini-Ehungu 0 Ce lestin Ndosimao Nsibu 0 Mathilde Bothale Ekila 0 Fran cois Bompeka Lepira 0 Nazaire Mangani Nseka 0 Andrew C. Wilber, Southern Illinois University School of Medicine, United States of America 0 1 Division of Hemato-oncology and Nephrology, Department of Pediatrics, University Hospital of Kinshasa, School of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo, 2 Intensive Care Division, Department of Pediatrics, University Hospital of Kinshasa, School of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo, 3 Department of Internal Medicine, University Hospital of Kinshasa, School of Medicine, University of Kinshasa, Kinshasa, Democratic Republic of Congo, 4 Division of Nephrology and Dialysis, Department of Internal Medicine, University Hospital of Kinshasa, School of Medicine, University of Kinshasa , Kinshasa , Democratic Republic of Congo Background: The prevalence of Sickle cell disease is extremely high in Democratic Republic of Congo. Despite this high prevalence of the disease, data on renal abnormalities in children are rare. Method: The study proposed to assess blood pressure, glomerular function, urea and uric acid levels in 65 steady state Congolese children with homozygous sickle cell disease and 67 normal controls. Results: In Hb-SS group, blood pressure level tended to be lower than Hb-AA groups but there was no statistically significant difference (p.0.05) between the two groups. The absolute values for GFR corrected for BSA were significantly higher in Hb-SS group compared to Hb-AA group (130.5634.1 ml/min/1.73 m2 vs 113.7624.5 ml/min/1.73 m2; p = 0.004). Children with Hb-SS were more likely to hyperfiltrate (30.8% of subjects) than children with Hb-AA (6.1% of subjects). Proteinuria was found in 4 (6.2%) children with Hb-SS. Uric acid level was significantly increased in children with Hb-SS compared to corresponding values in control group (4.461.3 mg/dl vs 3.561.1 mg/dl; p,0.001). Urea level was significantly decreased compared to corresponding values in Hb-AA group (15.368.3 mg/dl vs 22.9610.1 mg/dl; p,0.001). Conclusion: Hyperfiltration, low creatinine, lower urea and high uric acid are more common in children with sickle cell disease than in normal controls. - Sickle cell disease (SCD) is an autosomal recessive genetic condition due to a mutation in the beta-globin gene resulting in replacement of glutamic acid in position 6 of the beta-globin chain by valine resulting in an abnormal haemoglobin HbS molecule. SCD is the commonest genetic disease worldwide. The highest frequencies of homozygous SCD in the world occur in subSaharan Africa where 3 to 4% of populations are affected [1]. The sickle cell genes occur commonly in areas of the world with intense malaria transmission. Democratic Republic of Congo (DRC) has the second highest population of SCD patients in the whole world after Nigeria. The prevalence of SCD is extremely high with 25 to 30% of sickle cell trait carrier in the general population. Recent population-based studies have calculated the prevalence to be 1.4% in Congolese newborns and the incidence to be approximately 50,000 newborns per year [1,2]. The kidney is an organ of considerable impact on the clinical course of sickle cell patients. In DRC, the main haplotype of SCD is the Central African Republic (CAR) globin gene, the most severe form of the disease. The CAR bs globin gene haplotype was found significantly more often in patients with chronic renal failure (CRF) suggesting a genetic predilection [3]. Despite this high prevalence of the disease in our midst and the risk of CRF, information about renal complications in pediatric population suffering from SCD in DRC are unknown. Probably this renal impairment is under-reported in African children, poverty and the paucity of pediatric nephrologists and hematologists in this region should contribute to this fact. In addition, SCD and renal diseases are not regarded as a major health problem in DRC confronted to infectious diseases and malnutrition [4,5]. The objective of this survey was to investigate early detection of renal abnormalities in children suffering from SCD in a context of limited resource settings. Our ultimate goals are to develop the basis for designing and implementing effective preventive interventions for renal complications in sickle cell patients. These researches also seek to inform clinical practice, education and counseling guidelines. In this first report, we assess glomerular function in children suffering from homozygous SCD in Kinshasa, DRC. Materials and Methods Ethical consideration Since all participants were minors, they provided assent and their legal guardians provided consent for study participation. This consent procedure was reviewed and approved by the National Ethical Committee of the Public Health School of the University of Kinshasa, Kinshasa, DRC. Study design and population The present cross-sectional study is the first part of a larger ongoing study of renal complications in Congolese sickle cell patients suffering from SCD. The study was conducted in 2 hospitals of Kinshasa. These hospitals were University Hospital of Kinshasa (Division of pediatric nephrology) and Sickle cell centre of Yolo. These hospitals provide most of the non-private paediatrics beds in Kinshasa for sickle cell patients. Patients were selected in the outpatient clinic of the Pediatric Hematology Unit of the University Hospital of Kinshasa and in the outpatient clinic of Sickle Cell Centre of Yolo. The starting number was randomly chosen from the first three in the section call. For each case, one control child matched for age, sex and place of residence were recruited into the study. Five ml of blood sample were collected and were screened for haemoglobin phenotypes at the Laboratory of Haematology of Centre Medical Monkole of Kinshasa. The following clinical and laboratory information were collected and analyzed (i) Demographic characteristics (ii) blood pressure (iii) creatinine, uric acid and urea at admission and (iv) proteinuria. Laboratory analysis All patients were free of pain for at least 15 days and had not been hospitalized or transfused for at least 100 days before the study. Children with prior known proteinuria, hypertension, diabetes, HIV, HCV, renal and cardiovascular diseases were excluded by appropriate clinical and laboratory investigations. Children under hydroxyurea therapy were also excluded. Blood samples were collected in all subjects. Sickle cell screening was performed using isoelec (...truncated)