Red Blood Cell Lifespan

Background:

A low amount of red blood cells in the blood of patients with limited kidney function is a
well known problem. Besides the lack of substances in the blood like iron or erythropoietin
the shortened survival of red blood cells leads to the low red blood cell count. Red blood
cells of patients on kidney replacement therapy (dialysis) die earlier than those of healthy
persons. They live only about 70 days compared to 120 days in healthy humans. Today little
is known about the causes for the shorter survival of the red blood cells in patients on
dialysis. Because inflammation leads to a shorter life of the red blood cells in people
suffering from several diseases leading to inflammation we would like to learn about the
role of inflammation in the shortened life of red blood cells of dialysis patients.

When red blood cells are dying the content is broken down to several substances. One of
these substances is the gas carbon monoxide (CO). The carbon monoxide is exhaled with the
breath. The more red blood cells die the more CO is exhaled. That's why we can calculate the
lifespan of the red blood cells when we measure the amount of CO in breath at the same time
as the red blood cell count in the blood.

Aim of the study:

We aim to learn about the influence of inflammation of on red blood cell survival in
dialysis patients. To look for factors with effect on inflammation or red blood cell
survival, for example type of dialysis access, medication or kind of dialysis treatment.

Study procedures:

Over the course of the 18 month study, 6 observational assessments will take place. If the
patient experiences a situation with increased inflammation during the study period (for
example any kind of infection or intervention) up to two more study visits will take place.
Each study visit will include blood sampling, performed without the need for an extra needle
stick, and a breath sampling in order to calculate the red blood survival and to measure
markers for inflammation in the blood. The breath sample will be taken using the easy to use
GaSampler device developed by a company called Quintron especially for medical breath
sampling.

In order to get a sample of air at the patient's home for calculation of carbon monoxide
produced in the body we will ask the patients to take home an open empty plastic bottle
before each study visit. The bottle should be kept overnight on a table or sideboard in the
apartment. Before leaving home for hemodialysis or in clinic visit the patient will seal the
plastic bottle with the top, take it to the dialysis center and hand it to the research
staff.

Risks:

The amount of the additional blood drawn is 30 ml; this is the amount 2 tablespoons, at each
study visit. This does not harm the patient. The breath sampling does not imply any risk.