Association Between L-Arginine Levels and Microalbuminuria in Sickle Cell Disease: A Cross-Sectional Study in a Tertiary Hospital in Northwest Nigeria

Abstract

Background: Sickle cell disease (SCD) is highly prevalent in Nigeria and is frequently complicated by sickle cell nephropathy, which often begins with asymptomatic microalbuminuria. Chronic hemolysis leads to nitric oxide depletion and vasculopathy, and L-arginine, its substrate, may serve as a biomarker of disease severity. Aim: To determine the relationship between serum L-arginine levels and microalbuminuria among adolescents and adults with SCD in Kano, Nigeria. Materials and Methods: This comparative cross-sectional study was conducted among patients aged ≥16 years attending hematology clinics of Aminu Kano Teaching Hospital and Murtala Muhammad Specialist Hospital. Participants were screened for microalbuminuria and categorized into microalbuminuria and non-microalbuminuria groups. Serum L-arginine, lactate dehydrogenase, total bilirubin and cystatin C were measured, and estimated glomerular filtration rate was calculated using cystatin-C–based equations. Results: Among 246 screened patients, microalbuminuria prevalence was 17.5%. Eighty participants were studied (43 with microalbuminuria, 37 controls). Patients with microalbuminuria had significantly lower serum L-arginine levels than controls ( P < 0.001). Markers of hemolysis (LDH and bilirubin) and cystatin C were significantly higher, while eGFR was lower in the microalbuminuria group (all P < 0.001). Conclusion: Reduced L-arginine levels are associated with microalbuminuria in SCD and may serve as an early marker of nephropathy. In resource-limited settings, routine microalbuminuria screening, with optional L-arginine assessment, can help identify high-risk patients and guide timely renal-protective interventions.