Chronic kidney disease (CKD) is a major global public health issue. The present project focuses on the role of apolipoprotein L1 (APOL1) in patients with stage 4 CKD (glomerular filtration rate between 15 and 29 mL/min/1.73 m²).

Chronic kidney disease (CKD) is a worldwide public health problem. The project concerns the apolopoprotein L1 at stage 4 of severe chronic kidney disease (defined by a glomerular filtration rate of 29-15 ml / min / 1.73 m2).

Traditional risk factors (diabetes, cardiovascular diseases) and non-traditional such as inflammation and malnutrition are prognostic factors of mortality in our population.

Other parameters, less frequently described, would predict complications and mortality in patients on dialysis and in pre-dialysis the Fibroblast growth factor-23 (FGF-23) that regulates phosphates metabolism (Pereira, Juppner et al. 2009) and the " N terminal fragment of brain natriuretic peptide" (NT-proBNP), which plays a major role in regulation of blood pressure and extracellular volume.

Studies have suggested that black populations (African Americans) have a more rapid decline in kidney function than whites (European Americains).

The role of two variants (G1 and G2) of the gene encoding apolipoprotein L1 (APOL1) was mentioned. These APOL1 variants are common in African Americans (more than 50% are carriers of at least one risk allele). Carriers of 2 risk alleles would present a more rapid progression to end stage and, high-risk genotypes would explain most of the excess CKD risk for people of African descent. These variants of APOL1 Chronic kidney disease (CKD) is a worldwide public health problem. Our project concerns the apolopoprotein L1 at stage 4 of severe chronic kidney disease (defined by a glomerular filtration rate of 29-15 ml / min / 1.73 m2).

Traditional risk factors (diabetes, cardiovascular diseases) and non-traditional such as inflammation and malnutrition are prognostic factors of mortality in caribean population.

Other parameters, less frequently described, would predict complications and mortality in patients on dialysis and in pre-dialysis the Fibroblast growth factor-23 (FGF-23) that regulates phosphates metabolism and the " N terminal fragment of brain natriuretic peptide" (NT-proBNP), which plays a major role in regulation of blood pressure and extracellular volume.

Studies have suggested that black populations (African Americans) have a more rapid decline in kidney function than whites (European Americains). The role of two variants (G1 and G2) of the gene encoding apolipoprotein L1 (APOL1) was mentioned. These APOL1 variants are common in African Americans (more than 50% are carriers of at least one risk allele). Carriers of 2 risk alleles would present a more rapid progression to end stage and, high-risk genotypes would explain most of the excess CKD risk for people of African descent. These variants of APOL1 would also be associated with atherosclerotic cardiovascular disease.

Inclusion Criteria:

• Patients 18 y and older, of both sexes, Afro Caribbeans
• Living in Guadeloupe
• Having been informed of objectives and constraints of the study and who have given their written consent.
• For patients with CKD : at stage 4 (GFR < than 30 ml / min / 1.73m2.), whatever the etiology of CKD, associated pathologies and treatments,
• For patients with normal renal function : serum creatinine < 10 mg/l.

Exclusion Criteria:

• Patients 18 y and older, of both sexes, Afro Caribbeans
• Living in Guadeloupe
• Having been informed of objectives and constraints of the study and who have given their written consent.
• For patients with CKD : at stage 4 (GFR < than 30 ml / min / 1.73m2.), whatever the etiology of CKD, associated pathologies and treatments,
• For patients with normal renal function : serum creatinine < 10 mg/l.

The study population will consist of adult patients (≥18 years) with stage 4 chronic kidney disease (CKD), defined by a glomerular filtration rate (GFR) between 15 and 29 mL/min/1.73 m², patients are afro-caribeans and living i Guadeloupe. Participants will be recruited from a unique center (University Center Hospital of Guadeloupe) involved in the study.