Doctors usually administer antibiotics
even in the event of a suspicion of blood poisoning, without first
ascertaining whether it is actually a bacterial sepsis, which in turn
greatly increases the risk of resistance to antibiotics developing.
is therefore important to identify and develop a fast and effective
therapy, if possible without the need to use antibiotics.
An antibody for everything
‘A newly developed antibody can bind almost all the bacteria that can trigger blood poisoning. So if there is suspicion of sepsis, the magnetic treatment could be started, regardless of which pathogen is in the blood.’
Empa researcher Inge Herrmann and her team are developing a solution
in collaboration with modelling expert Marco Lattuada from the Adolphe
Merkle Institute and doctors from the Harvard Medical School. The idea
for the treatment is the magnetic purification of blood. The principle
is, at least in theory, quite straightforward. Iron particles are coated
with an antibody that detects and binds the harmful bacteria in the
blood. As soon as the iron particles are attached to the bacteria, they
are removed from the blood magnetically.
However, there is (still) a small catch: So far, it has only been
possible to coat the iron particles with antibodies that recognise one
type of bacteria - but many different types of bacteria may be
involved, depending on the species causing the blood poisoning. Using
blood analysis, doctors must therefore first determine which bacteria is
causing the poisoning before the appropriate antibodies can be used.
"This blood analysis is time-consuming and time plays a vital role in
the treatment of blood poisoning," explains Herrmann. This is also the
reason for magnetic dialysis rarely having been used to date.
But a team at the Harvard Medical School led by Gerald Pier has
now developed an antibody that can bind almost all the bacteria that can
trigger blood poisoning - so if there is a suspicion of sepsis, the
magnetic treatment could be started immediately, regardless of which
pathogen is in the blood. This "allrounder" antibody to succeed in
isolating pathogenic bacteria - similar to using dialysis.
How harmful are the iron particles?
The method is not yet sufficiently mature to be used on patients.
In a next step, Herrmann wants to carry out tests with various other
germs and find out whether the Harvard antibody can actually bind
additional bacteria to itself. The nature of the iron particles is also
not to be underestimated. It may be the case that some particles remain
in the blood after the magnetic extraction has been carried out.
requirements for these carriers are thus clear: they must not harm the
human body. But Herrmann's team already has a solution ready in this
regard. The tiny iron particles are assembled into larger clusters and
are thus more responsive to the magnet. In addition, the researchers
have been able to demonstrate, in an in vitro simulation, that the iron
particles are broken down completely after only five days.
Further experiments still to come
In the future, it should therefore no longer be strictly necessary
to administer antibiotics as soon as there is a suspicion of sepsis.
Blood will be taken from the patient for analysis, and the patient
connected to a dialysis machine to cleanse the blood, no matter what
bacteria are in it. As soon as the doctors have the detailed blood
values, an antibiotic therapy tailored to the pathogen can be
introduced, if necessary.
This idea is currently just a future ambition, as there are still
numerous issues that need to be clarified. Firstly, it is imperative
that this method is used in the initial stage of sepsis, when the damage
has not yet spread from the blood to the organs or bodily functions,
and there is also the issue of how well this treatment will work in
unstable patients or patients with pre-existing conditions. But Herrmann
and her team are optimistic - and also a step closer to achieving a new
and more gentle treatment for sepsis.