In hemodialysis population the study team finds high concentrations of toxic trace elements (2 times higher than the general population for cadmium 4 to 13 times for lead). Several recent studies suggest a role of chronic exposure to cadmium in the loss of residual renal function, osteoporosis, graft failure, arteriosclerosis, as well as in excess cardiovascular mortality.

Moreover, in hemodialysis population, a deficit of certain essential trace elements (manganese, selenium, zinc) is observed. For example, in the population undergoing chronic hemodialysis, a zinc deficiency is found in 40 to 78% of cases. Zinc is a cofactor of more than 70 enzymes.

In this observational cohort, the study team seeks to understand the impact of HD and HDF on the serum concentrations of heavy metals and also oligometals, by studying their concentrations in the dialysate during dialysis sessions by inductive coupled plasma mass-spectrometry (ICP-MS).

Primary objective: Evaluate the trace element concentration (heavy metals Cd and Pb and oligometals: Fe, Zn, Cu, Mn and also Se) in the dialysate before and during dialysis session. By studying the variation in concentration between the initial concentration of trace element in the dialysis fluid and the final concentration after membrane in the dialysate (waste pipe).

Method : Prospective study, in dialysis population, inclusion period will be from September 1, 2021 to January 31, 2022, in Ambroise Paré hospital, Paris, France. Duration of follow-up will be 1 day.

Dialysate samples will be taken in the venous injection site before connecting the patient, at 0 and 10 minutes after disinfection.

After connecting the patients, post-membrane dialysis sample (waste pipe) will be taken at 30, 60, 120 and 180minutes. Trace element dosage will be done by ICP-MS.

Inclusion Criteria:

• Age over 18;
• End-stage chronic renal failure in chronic dialysis;
• Duration of dialysis session ≥3h;
• Vascular approach: arteriovenous fistula;
• Affiliation to a social security scheme or entitled.

Exclusion Criteria:

• Opposition to participate to the study;
• Daily dialysis;
• Duration of dialysis session < 3h and > 8h;
• Vascular approach: venous catheter; Weekly dialysis session ≤3; Patient under french AME health system.

Dialysis patients