The half-lives of neutrophils in the blood and lungs of patients with cystic fibrosis

Remarkably little is known about the lifecycle of neutrophils while this cell
type is important in the pathogenesis in CF. Knowledge about this lifecycle is
important for both for fundamental insights in the immune system under
homeostatic conditions, but also under conditions of systemic inflammation.
This will lead to an important increase in the understanding of the
pathogenesis of CF but also for other chronic inflammatory diseases of the lung
such as COPD. An important difficulty is the development of new
medications is is the lack of knowledge on the basal characteristics of
neutrophils under conditions of health and chronic inflammation: how fast they
are produced, how long they remain in the blood and tissues and where they are
cleared. Little is described in literature regarding these topics. In the 60's
and 70's studies were performed on the lifespans of neutrophils, but with
inadequate techniques. These data probably underestimate the lifespans of these
cells, but they are still mentioned in modern tekst books.

Objective of the study:
The results of this study will lead to an improved insight in the lifecycle of
these cells in health and diseases, and our results will be of importance for
more insight in chronic inflammatory diseases particularly CF. For example, it
will improve our ability to interpret the results from previous and future
intervention studies that block survival and production of leukocytes.

Study design:
On day one the volunteers or patients will come to the clinic with an empty
stomach.
First we will withdraw 20ml of blood for baseline measurements of glucose
levels and DNA deuterium enrichment.
After that, the volunteers/patients will be orally administered 1g of
deuterated glucose per kilogram bodyweight in 12 doses over a period of 6
hours. Also, after 1, 3 and 6 hours after the first administration we will
withdraw two drops of blood by skinprick to determine the amount of deuterated
glucose in the blood of the volunteer. During this day, the volunteer will
receive low-carb breakfast and lunch.
At 5 more timepoints, the volunteer will come to the clinic to donate 20ml of
blood. The exact days after intake of glucose differ for each volunteer but
will not be in weekends or more than two days in a row. (A clear scheme of the
withdrawals can be found in the "onderzoeksprotocol", paragraph 3.2.). On 2
days (7 days apart see table 2 page 13/25 of protocol) sputum will be collected.
From the collected blood and sputum white blood cell populations will be
separated using high performance FACS sorting. DNA from these cells will be
isolated and analysed for deuterium enrichment using a combination of gas
chromatography and mass-spectometry.
These data will be fed to a mathematical model, which can calculate the
half-lives of the cells.

Nature and extent of the burden and risks associated with participation,
benefit and group relatedness (if applicable):
Risks:
The deuteriated glucose used and sputum induction procedure are considered
safe, so risks are negligible
Burden:
Subject will pay five visits to the clinic for blood withdrawl. Each visit,
20ml of blood will be withdrawn, which can be easily missed by adults.
Besides, subjects will spend one day in hospital for one blood withdrawal and
the intake of 1g/kg bodyweight of glucose