is treated by replacing the missing clotting factor
in the blood. This is done by injecting a product
that contains the needed factor into a vein. Bleeding
stops when enough clotting factor reaches the
bleeding site. When bleeding is into a joint it
is very important that treatment is given as quickly
as possible to prevent long-term damage.
factors are found in the following treatment preparations
in order of increasing concentration:
are considerable drawbacks to the use of whole
blood in the treatment of Haemophilia. Firstly,
it must be fresh because the activity of the clotting
factors in the drawn blood decreases quickly with
time. Secondly, the red cells it contains must,
of course, be compatible with those of the recipient.
Thirdly, it takes a large volume of whole blood
to stop a bleed and this volume may overload the
circulation and cause the heart to fail.
plasma, in which the cells have been removed leaving
the blood proteins including the clotting factors,
is better but the problems of overload remain.
The life of the clotting factors is preserved
by making a product called fresh frozen plasma
(FFP). FFP is still the only product available
for treatment in some countries.
is derived from blood and contains a high concentration
of clotting factors. It is relatively inexpensive
and easy to produce. It is effective, but
is less safe from viral contamination than concentrates
and is harder to store and administer.
concentrates are very effective but are expensive.
They can be made from human blood (called plasma-derived
products) or manufactured using genetically engineered
cells that carry a human factor gene (called recombinant
products). There are several levels of purity
(the concentration of factor) ranging from intermediate
to very high depending on the manufacturing process.
The therapeutic safety of each product depends
on the methods used to prevent, remove, or inactivate
viruses that may be present in the source plasma.
with mild Haemophilia A sometimes use desmopressin
(also called DDAVP), a synthetic hormone that
stimulates the release of factor VIII.
treatment products and proper care, people with
Haemophilia can live perfectly healthy lives.
Without treatment, Haemophilia can cause crippling
pain, severe joint damage, disability, and early
death. Tragically, only about 25 percent of people
with Haemophilia in the world receive adequate
treatment. The World Federation of Haemophilia
works to improve the level of treatment and care
around the world.
there a cure for Haemophilia?
is no cure for Haemophilia yet but gene therapy
remains an exciting possibility and holds out
the prospect of a partial or complete cure for
Haemophilia. There are many technical obstacles
to overcome, but it is encouraging to see that
clinical trials for both factor VIII and IX have
is Haemophilia diagnosed?
Haemophilia is diagnosed by measuring the level
of factor activity in the blood.
the mother is a carrier, testing can be done before
a baby is born. Prenatal diagnosis can be done
at 9 to 11 weeks by chorionic villus sampling
(CVS) or fetal blood sampling at a later stage
(18 or more weeks).
A is diagnosed by testing the level of factor
VIII coagulation activity in the blood. Haemophilia
B is diagnosed by measuring the level of factor
tests can be done at a Haemophilia treatment centre.
are clotting factors?
Clotting factors are proteins in the blood that
make blood clot. There are 13 main factors (identified
by roman numerals) that work together to produce
a clot. If one factor is missing, the chain reaction
is broken, clots will not form properly, and bleeding
people with Haemophilia avoid aspirin?
with Haemophilia should not take aspirin (ASA
or acetylsalicyclic acid), or anything containing
aspirin, because it interferes with the stickiness
of the blood platelets, and adds to problems with
(acetominophen) is a perfectly safe alternative
to aspirin to relieve pain, for example, headaches.
people with haemophilia may develop inhibitors
to the clotting factors they are missing. This
may affect around 30% of patients with haemophilia
A; it is less common in haemophilia B. An inhibitor
is another name for an antibody, which is what
the body produces when faced with a foreign substance
it does not recognise. The inhibitors bind to
the clotting factor and reduce its ability to
do its job properly. The effect of inhibitors
varies from person to person, and treatment also
varies accordingly. If you want to know more about
inhibitors and their treatment, your Haemophilia
Centre will be able to provide you with information.
Most inhibitors emerge after relatively few treatments.
In general, the more treatments a person has had
without developing inhibitors, the less likely
he is to develop an inhibitor.
Prophylaxis is the regular use of clotting factor
concentrates to prevent bleeds before they start.
Injections of clotting factor are given two or three
times a week to maintain a constant level of factor
VIII or IX in the bloodstream. It can help reduce
or prevent joint damage. In countries with good
access to clotting factor concentrates, this is
becoming the normal mode of treatment for younger
patients, and can be started when the veins are
well developed (usually between the ages of two
and four years).
is a venous access device (port-a-cath)?
port-a-cath, or implantable venous access device
(IVAD), is implanted under the skin, usually in
the upper chest but there are models which can be
inserted into the arm. It has a small metal reservoir
with a rubber diaphragm which is connected to a
catheter which is then threaded into a large vein
in the chest or arm. The entire device is
surgically implanted under the skin so there is
no catheter that hangs out of the body. The device
provides ready access to a vein for administering
medications and fluids intravenously. It can also
be used for drawing blood samples.
device is accessed by inserting a special needle
through the skin and into the rubber diaphragm
of the reservoir. The medication or fluid is injected
into the device and it flows through the catheter
into the vein.
devices have made prophylaxis in Haemophilia much
easier for families because the problems of "finding
a vein" for infusion two to three times a week
are eliminated. However, there are risks involved
with their use, the most worrisome being that
of infection. Studies differ but some show an
infection rate as high as 50 percent. These infections
can usually be treated with intravenous antibiotics
but sometimes the device must be removed. Also,
there are other studies that show a risk of clots
forming at the tip of the catheter. Still, many
families have chosen to use the device in spite
of the risk because of the benefits. Like
any other procedure, one must weigh the risks