Genotype-dependent albuminuria in adult sickle cell disease in Kinshasa

Abstract

Albuminuria, which depends on multiple factors, is common in patients with sickle cell disease and can progress to chronic kidney disease. In this study, we investigated the frequency and determinants of albuminuria according to sickle cell disease genotype. This multicentre cross-sectional analytical study of adults with stable sickle cell disease was conducted in Kinshasa. Genotypes were categorised as follows: homozygous, HbSS; heterozygous, HbAS; albuminuria, urinary albumin/creatinine ratio (mg/g): grade A1, < 30; grade A2:30-300; or grade A3, > 300. In total, 247 patients with sickle cell disease were included: 205 homozygous and 42 heterozygous. Albuminuria was prevalent in 50.5% of homozygous and 56.1% of heterozygous patients. The multivariate analysis revealed that the factors independently associated with albuminuria in the homozygous group were age ≥ 30 years (p = 0.037), leg ulcers (p = 0.010), hypertension (p = 0.038), and C-reactive protein level > 6 mg/L (p = 0.033). In the heterozygous group, only hypertension (p = 0.009), C-reactive protein > 6 mg/L (p = 0.006) and a history of vaso-occlusive crisis (p = 0.014) emerged as factors independent factors. More than half of patients with sickle cell disease had albuminuria, which was independently associated with hypertension and inflammation in both groups. Furthermore, there was also an association between in albuminuria and age ≥ 30 years, manifestations of vasculopathy in the homozygous group and a history of vaso-occlusive crisis in the heterozygous group.