FACTS ABOUT
Immune Thrombocytopenic Purpura

What is it?

Immune Thrombocytopenic Purpura (ITP) is a disorder of the blood.

Immune refers to the immune system's involvement in this
disorder.  Antibodies, part of the body's immunologic defense
against infection, attach to blood platelet, cells that help stop
bleeding, and cause their destruction.  Thrombocytopenia refers
to decrease in blood platelet.  Purpura refers to the purplish-
looking areas of the skin and mucous membranes (such as the
lining of the mouth) where bleeding has occurred as a result of
decreased platelet.

Some cases of ITP are caused by drugs, and others are
associated with infection, pregnancy, or immune disorders such as
systemic lupus erythematosus.  About half of all cases are
classified as "idiopathic," meaning the cause is unknown.

What are the symptoms of ITP?

The main symptom is bleeding which can include bruising
("ecchymosis") and tiny red dots on the skin or mucous membranes
("petechiae").  In some instances bleeding from the nose, gums,
digestive or urinary tracts may also occur.  Rarely, bleeding
within the brain occurs.

How is ITP diagnosed?

The physician will take a medical history and perform a thorough
physical examination.  A careful review of medications the
patient is taking is important because some drugs can be
associated with thrombocytopenia.  A complete blood count will be
done.  A low platelet count will establish thrombocytopenia as
the cause of purpura.  Often the next procedure is a bone marrow
examination to verify that there are adequate platelet-forming
cells (megakaryocyte) in the marrow and to rule out other
diseases such as metastatic cancer (cancer that has spread to the
bone marrow) and leukemia cancer of the blood cells themselves). 
Another blood sample may be drawn to check for other conditions
sometimes associated with thrombocytopenia such as lupus and
infection.

Acute and Chronic Form of Thrombocytopenic Purpura

Acute (temporary) thrombocytopenic purpura is most commonly seen
in young children.  Boys and girls are equally affected. 
Symptoms often, but do not necessarily,  follow a viral
infection.  About 85 percent of children recover within 1 year
and the problem doesn't return.  

Thrombocytopenic purpura is considered chronic when it has
lasted more than 6 months.  The onset of illness may be at any
age.  Adults more often have the chronic disorder and females are
affected two to three times more than males.  The onset of
illness may be at any age.

How is ITP treated?

If the doctor thinks a drug is the cause of the thrombocytopenia,
standard treatment involves discontinuing the drug's use. 
Infection, if present, is treated vigorously since control of the
infection may result in a return of the platelet count to normal.

The treatment of idiopathic thrombocytopenic purpura is
determined by the severity of the symptoms.  In some cases, no
therapy is needed.  In most cases, drugs that alter the immune
system's attack on the platelet are prescribed.  These include
corticosteroids (i.e., prednisone) and/or intravenous infusions
of immune globulin.  Another treatment that usually results in an
increased number of platelet is removal of the spleen, the organ
that destroys antibody-coated platelet.  Other drugs such as
vincristine, azathioprine (Imuran), Danazol, cyclophosphamide,
and cyclosporine are prescribed for patients only in the severe
case where other treatments have not shown benefit since these
drugs have potentially harmful side effects.

Excepts in certain situation (e.g., internal bleeding and
preparation for surgery), platelet transfusion usually are not
beneficial and, therefore, are seldom performed.  Because all
therapies can have risks, it is important that overtreatment
(treatment based solely on platelet counts and not on symptoms)
be avoided.  In some instances lifestyle adjustments may be
helpful for prevention of bleeding due to injury.  These would
include use of protective gear such as helmets and avoidance of
contact sports in symptomatic patients or when platelet counts
are less than 50,000.  Otherwise, patients usually can carry on
normal activities, but final decisions about activity should  be
made in consultation with the patient's hematologist.

Where can I obtain further information on ITP?

Blood specialists (hematologist) are experts in the diagnosis and
treatment of these disorders.  These doctors practice in most
mid-and large-size cities.  A majority of medical centers have
hematology divisions in their medicine or pediatrics departments,
and patients who need evaluation, treatment, or information can
often be referred there.

Additional information can be obtained from the
National Organization for Rare Disorder at P.O. Box 8923, New
Fairfield, Connecticut 06812; telephone (203) 746-6518.







NIH Publication No. 90-2114
September 1990




U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health Service
National Institutes of Health
National Heart, Lung, and Blood Institute