Accelerated Immunosenescence and Chronic Kidney Disease (IRIS)

The aim of this study is to investigate the impact of renal function and dialysis techniques on the percentage of senescent T lymphocytes.

The immunosenescence is a complex and profound remodeling of the immune system during life. It is mainly due to thymic involution and repeated antigenic stimulation. Kidney disease is associated with a decrease in adaptive immunity as evidenced by the decrease in vaccine response and increased susceptibility to infections, similar to those observed in the elderly population. However, data on aging of the immune system in chronic kidney disease remains incomplete. Furthermore, the determinants of immunosenescence are not also not known. It is possible that "uremic" factors help explain the phenotypic and functional changes of lymphocytes, as antigenic stimuli associated with repeated bio-compatible materials used in dialysis contact. The purpose of this study is to describe the phenotypes of the immune system of renal and analyze the determinants of these changes.

Patients in this group control (normal renal function) are followed in the urology department. A blood sample is performed on the day of inclusion.

Patients in this group suffer from renal failure stage 4 and are not under dialysis. A blood sample is performed on the day of inclusion.

Patients with renal failure, under peritoneal dialysis for at least 3 months. A blood sample is performed on the day of inclusion.

Patient with renal failure, under hemodialysis for at least 3 months. A blood sample is performed on the day of inclusion.

The primary outcome measure is the percentage of CD 4/8+ CD 57+ CD 28- lymphocytes by flow cytometry. The technique used is a 6 colors surface labelling of T lymphocytes to study the T cell senescent population.

The telomerase activity of T lymphocytes is assessed by a method of Polymerase chain reaction (PCR)-ELISA.

This level is obtained by flow cytometry after permeabilization and labelling of Peripheral Blood Mononuclear Cells (PBMC).

RTE T cells will be defined by flow cytometry, according to co-expression of CD 4, CD 8,CD 31 and CD 45RA

Study of telomere length is performed after extraction of DNA from isolated T cells. The length is determined by a quantitative PCR technique relative to a reference gene.

Inclusion Criteria: Patient able to understand the reason of the study Patient not opposed to the conservation of biological samples for scientific research Exclusion Criteria: Patient suffering from psychotic illness Any history of immunosuppressive therapy (except steroids up to 5mg/day) History of cancer (except skin cancer) or treated hematological malignancy Infectious episode required hospitalization not older 3 months Hepatitis B or C infection HIV infection, active or inactive For dialysis patients: renal failure on dialysis for less than 3 months and/or have benefited from two techniques for renal replacement therapy in the last 6 months