Karen E. Itokua1, Jean Robert Makulo2,4*, François B. Lepira2, Michel N. Aloni1, Pépé M. Ekulu1, Ernest K. Sumaili2,
Justine B. Bukabau2, Vieux M. Mokoli2, Augustin L. Longo2, François M. Kajingulu2, Chantal V. Zinga2,
Yannick M. Nlandu2, Yannick M. Engole2, Pierre Z. Akilimali3, René M. Ngiyulu1, Jean Lambert Gini1
and Nazaire M. Nseka 2

* Correspondence: jrmakulo2016@gmail.com
2Nephrology Unit, Department of Internal Medicine, University of Kinshasa
Hospital, University of Kinshasa, Kinshasa, Democratic Republic of the Congo
4Faculty of Medicine, University of Kinshasa Hospital, Kinshasa, Democratic
Republic of the Congo
Full list of author information is available at the end of the article

Abstract

Background: Oxidative stress is thought to be involved in the pathogenesis of microalbuminuria in Sickle cell anemia (SCA). Antioxidant enzymes such as glutathione peroxidase (GPx) and Cu-Zn superoxide dismutase (SOD) may play an important protective role. This study aimed to evaluate the association between albuminuria and these two antioxidant enzymes.
Methods: We consecutively recruited Steady state children aged between 2 and 18 years old with established diagnosis of homozygous SCA in two hospitals of Kinshasa/DR Congo. The relationship between Urinary Albumin Creatinine Ratio (UACR) and other variables of interest (age, systolic blood pressure, diastolic blood pressure, plasma  GPx and Cu-Zn SOD, free plasmatic hemoglobin, LDH, indirect bilirubin, white blood cells (WBC), percentage of fetal hemoglobin, serum iron, ferritin, CRP) was analyzed by Bivariate correlation (Pearson’s correlation coefficient).
Microalbuminuria was defined by urine albumin/creatinine ratio between 30 and 299 mg/g.
Results: Seventy Steady state Black African children with SCA (56% boys; average age 9.9 ± 4.3 years; 53% receiving hydroxyurea) were selected. Prevalence of microalbuminuria was 11.8%. LDH (r= 0.260; p = 0.033) and WBC count (r=0.264; p = 0.033) were positively correlated with UACR whereas GPx (− 0.328; p = 0.007) and Cu-Zn SOD (− 0.210; p = 0.091) were negatively correlated with UACR.
Conclusions: Albuminuria is associated with decreased antioxidant capacity and increased levels of markers of hemolysis and inflammation. Therefore, strategies targeting the reduction of sickling and subsequent hemolysis, oxidative stress and inflammation could help preventing or at least delaying the progression of kidney disease in SCA children.
Keywords: Sickle cell anemia, Albuminuria, GPx, Cu-Zn SOD, Lactate dehydrogenase, Inflammation

Itokua et al. BMC Nephrology (2016) 17:178
DOI 10.1186/s12882-016-0398-0