An Overview of Thrombophilia

A n O v e r v i e w o f T h r o m b o p h i l i a
A
Q & A
W I T H
A M Y D . S H A P I R O , M D
Q: What is “thrombophilia”?
A: Thrombophilia is a term used to
in some patients and families for
describe a group of conditions in
this tendency to an increased
which there is an increased tendency,
risk of excessive blood clotting,
often repeated and often over an
we are still not able to make
extended period of time, for exces-
this determination in all
sive clotting. These include con-
cases. This means that there
ditions due to:
is still more to be under-
1) family history of clotting or a
stood about why some
diagnosis based on a demon-
persons and families have
strated genetic mutation such as
thrombophilia.
factor V Leiden, protein C and
S deficiencies, antithrombin
Q: Is it a new
and prothrombin 20210A muta-
disease?
tions.
2) an acquired condition such
A: Thrombophilia is not
as lupus inhibitor or antiphos-
a new disease, but it has
“ALTHOUGH WE ARE NOW
pholipid antibody, which can
become a more recognized
occur in persons with systemic
and discussed topic due to
ABLE TO DETERMINE THE
lupus erythromatosis. The devel-
an increased ability to test
opment of a blood clot is called
for and identify some of the
UNDERLYINGCAUSE IN SOME
thrombosis. The vascular system
underlying contributing
V
includes both the venous system (the
abnormalities.
PATIENTS AND FAMILIES FOR
OL
veins that deliver blood from the tis-
6
sues to the heart) and the arterial sys-
THIS TENDENCY FOR AN
Q: Who has
,
IS
tem (the system that delivers blood
thrombophilia?
SUE
from the heart to the tissues).
INCREASED RISK OF EXCESSIVE
Thrombotic episodes may occur in either
A: Thrombophilia affects a
5
system. The symptoms relate to the part
BLOOD CLOTTING, WE ARE STILL
large number of people in the
l
H
of the vascular system in which they occur, the
world. People who experience episodes of
EMA –
extent of the clot and whether the clot breaks
NOT ABLE TO MAKE THIS
thrombosis, either as an isolated event or as a
W
off and travels to another part of the body (eg,
repeated event, may be affected with a throm-
ARE
the lungs—pulmonary embolus, the brain—embolic
DETERMINATION IN ALL CASES.”
bophilic disorder. There are people who have
stroke, etc). There are different terms used to fur-
inherited an abnormality, such as factor V Leiden
l
ther define these thrombotic episodes such as
or activated protein C resistance, who have an
13
deep vein thrombosis (DVT) or peripheral vas-
increased tendency for thrombosis, but who may
cular disease, when the clots are in the arterial
never personally experience a blood clot. They
l
system (usually in the extremities). Although we
may, therefore, have a known thrombophilic
are now able to determine the underlying cause
condition, but never experience a thrombosis.
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Both children and adults may have thrombophilia,
but it is more commonly diagnosed during the
adolescent and adult years due to normal
H R O M B O P H I L I A I S A L S O R E L A T E D
T
changes in the hemostatic balance that
occurs with growth and aging. Both men and
T H E
P R O V I D E R S
T H A T
S T A F F
women may have thrombophilia. In fact, women
C E N T E R S M A Y B E W E L L S U I T E D
who have thrombophilia may have an increased
tendency to show symptoms due to the contributing
S P E C I A L I Z E D S E R V I C E S T O T H I S
effects of pregnancy or use of hormonal agents.
Q: How many people in the United
States have thrombophilia?
described by Dr. Dahlback in 1993. Acquired thrombophilia
A: Thrombosis is a very common medical problem. It is
refers to a group of disorders that an individual is not
estimated that approximately two million people experi-
born with, but may develop throughout his or her life
ence a DVT each year in the United States. In addition,
d u e
t o a n o t h e r
i l l n e s s o r
s i t ua t i o n . A n
nearly half of patients with deep vein clots experience long-
example of acquired thrombophilia is the development
term health consequences that adversely affect their qual-
of a lupus anticoagulant or antiphospholipid antibody syn-
ity of life and require millions of dollars of treatment.
drome.
Thrombosis may manifest itself as the formation or
presence of a blood clot in a blood vessel or one of the
Q: Who takes care of patients
cavities in the heart. In fact, emboli (clots or plugs brought
with thrombophilia?
by the blood from another blood vessel and forced into
a smaller vessel so as to obstruct the circulation) from deep
A: Many healthcare professionals take care of people with
vein clots are a leading cause of death in hospitalized
thrombophilia. For example, primary healthcare providers
patients. Annually, 200,000 to 300,000 patients develop
(pediatricians, internal medicine physicians, family prac-
this form of clot for the first time during a hospitaliza-
titioners, obstetricians and gynecologists, emergency physi-
tion. Nearly 40% of these patients suffer pulmonary emboli
cians, etc) may all care for patients with this disorder.
(a clot that travels to the lung and obstructs a significant
Subspecialists, such as pulmonologists, vascular surgeons,
amount of blood flow to the organ) that are fatal in 30%
neurologists and hematologists, may also care for this patient
of the cases.
population. Other specialists, such as pathologists and
Recent research shows that these disorders contribute
2001
radiologists, may provide services to these patients includ-
significantly to morbidity and mortality in the United States.
ing diagnostic and interventional services. There is an
Each year, more than 600,000 Americans die from abnor-
increasing tendency to have these patients seen at some
T/OCT
mal blood clots.
point by a facility or physician that provides expertise in
Factor V Leiden is the most common inherited abnor-
SEP
this area.
mality causing an increased tendency to thrombosis, and
l
it affects approximately 5% to 7% of the Caucasian pop-
Q: How is thrombophilia related
ulation of European descent in the United States. Many
ARE
to hemophilia?
W
of these people have not yet experienced a clot.
– EMA
A: Thrombophilia is the reverse side of the process of
H
Q: What are the differences
blood clotting compared to hemophilia. While people with
between genetic and acquired
hemophilia have an increased tendency to bleed, people
thrombophilia?
14
with thrombophilia have an increased tendency to clot.
Just as hemophilia is caused by an abnormality of a blood-
A: Genetic thrombophilia is an inherited abnormality that
ll
clotting factor, some forms of thrombophilia are also caused
leads to an increased risk of thrombosis throughout a per-
by an abnormality or deficiency of a blood-clotting fac-
son’s life. The most common disorder that is an inher-
tor. In some cases these clotting factors may have an abnor-
ited thrombophilic disorder is factor V Leiden, initially

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concentrate” to treat their thrombophilia either on a long-
term or an intermittent basis, depending on the under-
T O H E M O P H I L I A I N T H A T
lying cause of their thrombophilia. Some people with throm-
bophilia are treated with medications that are classified
H E M O P H I L I A T R E A T M E N T
as blood thinners, which decrease a person’s ability to form
a clot. Examples of these medications include aspirin,
T O P R O V I D E
heparin, low molecular weight heparin and coumadin. There
are also some specific medications (thrombolytic agents)
P O P U L A T I O N , A S W E L L .
that are given under certain circumstances to dissolve clots.
People with hemophilia who have central venous access
devices that have become clotted may receive small doses
of these medications locally. People with thrombosis may
mality that leads to an increase in their function (such as
receive these agents in larger doses that are either given
factor V Leiden). Thrombophilia is also related to hemo-
at the site of thrombosis or systemically. People with throm-
philia in that the providers that staff hemophilia treatment
bophilia may receive medications only during a time of
centers (HTCs) may be well suited to provide specialized
increased risk of thrombosis or for a prolonged period of
services to this population, as well. People with hemophilia
time (even for a lifetime), depending on their specific diag-
may also inherit a thrombophilic abnormality; in fact, it
nosis and clinical circumstances.
has been shown that people with hemophilia who also
inherit factor V Leiden, begin bleeding at a later age and
Q: Is there a patient organization that
may bleed less frequently.
advocates for improved treatment and
more research?
Q: What kinds of treatment
do people with thrombophilia
A: Yes, there is a national organization called the “American
receive?
Thrombosis Association,” which has been formed to advo-
cate for the population affected with these disorders in
A: People with thrombophilia may receive medications
the United States. Go to www.airhealth.org on the Web—
that affect the coagulation system, just as people with hemo-
it is advocating for changes in airline practices to prevent
philia do, but not always in the same manner. Some peo-
“economy class syndrome.” Economy class syndrome is
ple with thrombophilia may receive “replacement factor
more accurately described as DVT. It occurs when blood
L
V
OL
“ P E O P L E W I T H
6
,
IS
T H R O M B O P H I L I A
SUE
M A Y R E C E I V E
5
M E D I C A T I O N S T H A T
l
H
A F F E C T T H E
EMA –
C O A G U L A T I O N
W
ARE
S Y S T E M , J U S T A S
P E O P L E W I T H
l
H E M O P H I L I A D O ,
15
B U T N O T A L W A Y S
l
I N T H E S A M E
M A N N E R . ”

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L
clots form in leg veins during long periods of immobil-
oping a pilot program to demonstrate the effectiveness
ity. These can be fatal if they enter the heart or lungs, and
of multi-disciplinary comprehensive care to persons with
there have been several deaths reported among airline pas-
clotting disorders who, in many cases, are currently receiv-
sengers. Airlines reject any link between cramped air travel
ing fragmented care. The goal is to prevent disease and
and DVT, but have started giving passenger advice through
improve medical outcomes. An expanded population served
inflight videos, magazines and their Web sites.
by HTCs may help in the long-term survival of these spe-
cialized treatment facilities.
Q: What is the CDC Pilot Program?
Q: How many HTCs are caring for
A: NHF is interested in thrombophilia because many HTCs
thrombophilia patients?
are providing care for these patients. The Centers for Disease
Control and Prevention (CDC) is also interested in throm-
A: Many HTC medical directors provide care to peo-
bophilia, due to its impact on the health of so many peo-
ple with clotting disorders. The demand for hemato-
ple in the United States. Similar to hemophilia care and
logical expertise from HTC providers is growing at a rapid
prevention services delivered through HTCs, CDC is devel-
rate.
B Y M A R K W. S K I N N E R , P R E S I D E N T, N H F
Afundamental To maintain financial viability which included numerous inter-
responsibility for
and to attract young physicians
views with members of the
the NHF Board of
into the field, we have seen a
bleeding disorders community,
Directors is to identify and
growing movement by HTCs
the NHF Board of Directors
respond to emerging issues.
across the country to incorpo-
voted last spring to have NHF
One such issue, which the Board
rate thrombophilia patients into
continue its core focus on hemo-
has been considering, is the
their care. Many, including the
philia and other bleeding disor-
2001
future supply of physicians
Centers for Disease Control and
ders, while also providing advo-
trained in the management and
Prevention (CDC), believe that
cacy, information and education
T/OCT
treatment of bleeding disorders.
merging bleeding and clotting
to meet the needs of NHF’s
The data is clear—without an
disorders into one network
provider constituents (regarding
SEP
aggressive effort, there will soon
(hemostasis and thrombosis
thrombophilia). In addition to
l
be a shortage of doctors to staff
centers) is one approach to
exploring additional strategies to
the hemophilia treatment center
address the shortage and meet
address the shortage, the Board
ARE
W
(HTC) network. It is also clear
the growing need for care of
will continue to evaluate this
there is no simple or single
thromboembolic disease.
position annually. This is not a
– EMAH
answer to address this eventual-
Since NHF works closely with
shift in NHF’s mission, but sim-
ity. A core part of NHF’s mission
HTCs and the CDC, the question
ply an affirmation that we must
is to support those who support
of what role NHF as an organi-
address this critical issue or risk
16
us—the doctors, nurses, physi-
zation would adopt in relation to
losing the critically important
cal therapists, social workers and
individuals with thrombophilia
HTC network.
ll
others who staff the HTCs.
was inevitable. Following an
intensive review of this issue,

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