Effect of RAS Inhibitors on Albuminuria, Hyperfiltration and Endothelial Dysfunction in a Sickle Cell Disease Population.

The prevalence of Sickle Cell Associated Nephropathy (SCAN) is increasing and is a growing concern. Microalbuminuria is detected in the early onset of SCAN. Noteworthy, as in diabetic nephropathy, hyperfiltration seems to be a frequent finding, with, in our series, an overall incidence of 57 % and suggests a pathological links between glomerular hyperpressure and glomerulosclerosis which occurs several years after. Nitric oxide (NO) deficiency and the renin angiotensin system (RAS) are likely to be involved in the glomerular hyperpressure leading to hyperfiltration. Renin angiotensin antagonists are currently given for NEPHROPROTECTION in numerous nephropathy including SCAN despite few available reports. The percentage of decrease of albuminuria or the percentage of responders (ie patient normalizing albuminuria) has never been reported to our knowledge in SCAN patients at the time of hyperfiltration. The focus of our study is therefore to 1) Quantify albuminuria reduction after 6 months RAS treatment (primary end point); 2) Quantify glomerular filtration rate (GFR) reduction after 6 months of RAS treatment, and to test the hypothesis of a beneficial effect of RAS inhibitors on several biomarkers assessing hemolysis, NO inhibition and the endothelial damages (secondary end points). The ultimate aim of our study is to identify relevant (new) biomarkers associated to hyperfiltration and/or albuminuria decrease (/normalization).