The effects of iron loading and iron chelation during human endotoxemia.

Iron homeostatis affects the immune system, and inflammation affects iron
homeostasis.
Iron acts as a catalytic molecule in the formation of oxygen radicals, needed
for effective killing of pathogens, but also enhances the inflammatory response
that is associated with organ dysfunction. Iron can modulate immune effector
mechanisms, such as cytokine activity, nitric oxide (NO) formation or immune
cell proliferation. Effects of iron overload include decreased
antibody-mediated phagocytosis, alterations in T-lymfocyte subsets, and
modification of lymphocyte distribution in different compartments of the immune
system. Furthermore, iron treatment has been associated with acute
exacerbations of infection. For example, in African children, iron
supplementation resulted in an increased rate of malaria and death, and in
children with cerebral malaria, the addition of the iron chelator deferoxamine
to a standard anti-malarial treatment resulted in an improved clinical course.
Therefore, gaining control over iron homeostasis is one of the central
battlefields in deciding the fate of an infection. This is of importance for
the development of future therapeutic targets for the treatment of sepsis.
Moreover, vascular injury is considered one of the main contributors to the
development of organ dysfunction during sepsis. Among other factors this is
caused by oxidative stress. The reduction of oxidative stress by an iron
chelator may represent a therapy to reduce endothelial damage during sepsis.

On the other hand, inflammatory stimuly enhance the production of hepcidin, a
key regulator of iron homeostasis that reduces iron uptake from te gut, and
abrogates the release of iron from macrophages. In this way continuous
stimulation of hepcidin production by inflammatory processes leads to 'anemia
of inflammation'. Anemia of inflammation is a frequently encoutered clinical
problem during chronic as well as acute systemic inflammation or infection.
Studying the pathofysiology of the disturbed iron balance during systemic
inflammation may lead to the development of future therapies.

However, human data on the effects of iron on innate immunity are lacking.
The human endotoxemia model permits elucidation of key players in the immune
response to a gram negative stimulus in vivo and serves as a useful tool to
investigate potential novel therapeutic strategies in a standardized setting.

We wish exploid the human endotoxemia model to study the immunomodulatory and
vascular effects of iron. This may lead to new therapies for patients with
systemic infection or inflammation, and for patients with inflammation
associated anemia. Also this study will contribute to our understanding or iron
homeostasis and hepcidin regulation.

The primary objective of the study is to determine concentration of circulation
cytokines na administration of LPS in the presence of iron sucrose (Venofer®),
Deferasirox (Exjade®) of placebo.

Double blinded placebo controlled parallel intervention study in healthy human
volunteers during expermental endotoxemia.

The volunteers will be randomized to 5 intervention groups.

1. iron loading + placebo prio to endotoxemia (N=12):
T=-2: Placebo orally
T=-1: iron sucrose (Venofer®) 1.25 mg/kg i.v.
T= 0: 2ng/kg LPS i.v.

2. Placebo + iron chelation prior to endotoxemia (N=12)
T=-2: Deferasirox (Exjade®) 30mg/kg orally
T=-1: Placebo i.v.
T= 0: 2ng/kg LPS i.v.

3. Placebo + Placebo prior to endotoxemia(N=12)
T=-2: Placebo orally
T=-1: Placebo i.v.
T= 0: 2ng/kg LPS i.v.

4. IJzer chelation prior to placebo (N=8)
T=-2: Deferasirox (Exjade®) 30mg/kg orally
T=-1: Placebo i.v.
T= 0: Placebo i.v.

5. Iron loading prior to placebo (N=8)
T=-2: Placebo oraal
T=-1: Ferrioxidesaccharaat (Venofer®) 1.25 mg/kg i.v.
T= 0: Placebo


Pre-hydration will be administered by infusion of 1.5 Liter 2.5% glucose/0.45%
NaCl solution in one hours, one hour prior to endotoxin administration.
Pre-hydratie zal worden gegeven door infusie van 1.5 liter 2.5% glucose/0.45%
NaCl oplossing in één uur, één uur voor de LPS toediening. (gelijktijdig
gestart met Ferrioxidesaccharaat (Venofer®) toediening)

A medical interview and physical examintaion are part of this study.
Venofer causes a reversible hyperferremia and deferasirox causses a reversible
hypoferremia.
Other side effects are described in the adjunctive SPC's

The administration of LPS induces flu-like sylptoms during approximately 4
hours. In total, approximately 350-400 ml blood will be drawn during each LPS
experiment and all urine will be be colleted.

The subjects have no direct benefit from participation in the study. A subject
fee is provided.