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Vernon, NY 13476
877.229.5248
It’s all about building a
company with one
mission, to fight for
what is essential:
YOUR HEALTH!
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What are Inhibitors?
Put simply, inhibitors
are antibodies to a clotting factor protein. Due to the abnormally low
levels of clotting factor in a hemophiliac's body, their immune system
may not recognize the protein as a safe and normal occupant of the person's
blood. In these cases the person's immune system targets the clotting
factor that is administered as treatment, thus removing it from the
bloodstream and diminishing the effectiveness of factor replacement
therapy or rendering it ineffective all together.
In cases where a drop
in the efficacy of their replacement therapy is noticed, patients are
often tested for an inhibitor. According to the CDC as many as 33% of
hemophiliacs may develop inhibitors to the clotting factor they infuse
to resolve and/or prevent bleeding episodes. Inhibitors are diagnosed
with a blood test that measures the inhibitor levels (or titer) in the
blood. The titer is measured in Bethesda Units (BU) with the mere presence
of a titer indicating an inhibitor while any titer over 5 is normally
considered to be a high responding inhibitor.
There are generally 3
methods of treatment for people with inhibitors.
- For people with low responding inhibitors it might
be possible to simply give them high doses of the clotting factor
they are deficient in. By doing so, there are not enough inhibitors
present to remove all of the administered clotting factor protein,
allowing the clot to form.
- ITT or ITI Therapy where the individual with the
inhibitor is given large volumes of clotting factor for a long period
of time (far more than what would normally required to stop or prevent
a bleed) in an attempt to force the body into accepting the factor
protein as a normal inhabitant of the blood. If all goes well, ITT
takes on average about a year for posative results but in harder cases
it can take much longer or not work at all.
- The third and final treatment involves the use of
bypassing agents. In this treatment inhibitor patients are given a
different clotting factor protein in an attempt to bypass the part
of coagulation that requires the protein they are missing. For example,
factor VII is often given to people with inhibitors to fVIII or fIX.
Factor VII can bypass the inhibitor because it activates a different
branch of the clotting cascade that can cause clot formation without
using factors VIII or IX. Some products contain multiple factors and
can therefore effectively do the same thing.
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