SUNDAY, March 23 (HealthDay News) -- Blood is life. And the rare
disease known as aplastic anemia robs the body of life by robbing
the body of blood.
The aplastic anemia patient's blood thins as the bone marrow
slows its production of blood cells. The results can range from
chronic fatigue to heart disease or from endless infections to cuts
that won't clot, depending on the type of blood cells that are
lacking.
But there's hope: Considered fatal as recently as two decades
ago, aplastic anemia is becoming a far more manageable disease.
Advances in drug therapies and improvements in the field of
transplantation have slashed the death toll, allowing patients to
live longer, fuller lives.
"We are getting better at treating aplastic anemia, either in
getting rid of it or treating its symptoms," said Dr. Jaroslaw P.
Maciejewski, with the Cleveland Clinic's Department of Hematologic
Oncology and Blood Disorders.
And those advances are helping doctors gain greater insights
into other, more prevalent, health conditions, such as heart
disease and leukemia.
An estimated 50,000 people develop aplastic anemia in the United
States each year, according to the U.S. National Institutes of
Health. (A related blood disorder, myelodysplastic syndrome, or
MDS, occurs when the bone marrow begins to produce poorly
functioning or immature blood cells. About 20,000 to 30,000 new
cases of MDS occur each year.)
It's important to note that many symptoms of aplastic anemia,
such as fatigue and infection, can also be caused by other
diseases, said Dr. Ronald Paquette, a blood disease researcher with
the University of California, Los Angeles' Jonsson Comprehensive
Cancer Center.
"If everyone who was fatigued thought they had aplastic anemia,
we'd be swamped," Paquette said.
Bone marrow -- the spongy material inside bones -- produces stem
cells that normally develop into the three main types of blood
cells -- red blood cells, white blood cells, and platelets.
"Essentially, the bone marrow is a factory of blood,"
Maciejewski said.
In patients with aplastic anemia, the stem cells have been
damaged, slowing or stopping the production of all blood cells.
The cause of the damage to stem cells remains unknown in more
than half of people with aplastic anemia. Some research has
suggested that stem cell damage occurs when the immune system
attacks the body's own cells by mistake, according to the National
Institutes of Health.
Aplastic anemia has also been linked to exposure to toxins such
as pesticides, arsenic and benzene. Some infectious diseases also
can cause the disorder, including hepatitis, Epstein-Barr virus,
cytomegalovirus, parvovirus B19, and HIV, as well as autoimmune
diseases like lupus and rheumatoid arthritis. Finally, some genetic
disorders have been linked to it.
Symptoms vary depending on the type of blood cells in
shortage:
- Too few red blood cells can mean not enough oxygen is carried
to the body, according to the NIH. People who have a low red blood
cell count often feel tired. Because the heart has to work harder
to pump blood to get enough oxygen to the body's organs and
tissues, heart disease can develop over time.
- Too few white blood cells weaken the body's defense against
infection. The patient may become ill more often, and the illness
can be severe.
- Too few platelets hamper the blood's ability to clot. Patients
with a low platelet count may bruise or bleed easily, and their
bleeding may be hard to stop.
Once aplastic anemia is detected, swift treatment is essential,
Paquette said. "Because it's a rare disease, it's important to be
treated at a specialized center," he said. "The most important
thing is to be seen by someone with a lot of experience treating
the disease early on."
For patients younger than 30, stem cell transplantation is often
the preferred treatment. For those with a matched sibling donor,
stem cell transplantation replaces the defective bone marrow with
healthy cells, and as many as 80 percent of patients enjoy a
complete recovery, according to the Aplastic Anemia & MDS
International Foundation Inc.
Advances in stem cell research and anti-rejection drugs have
meant that transplantations from unrelated donors also are becoming
more successful, Paquette said.
One promising avenue of treatment involves transplantation using
stem cells harvested from the umbilical cord of new mothers. "The
cells can be cryopreserved [frozen] and saved, then given to
unrelated donors," Paquette said. "It's quite encouraging."
For these patients, again, speed is of the essence. "The data
show the earlier you do a transplant, the better the outcome,"
Paquette said.
Patients whose transplants fail, or for whom transplantation is
not an option, often receive successful immunosuppressive therapy
with agents like anti-thymocyte globulin and cyclosporine. Response
rates typically range from 70 percent to 80 percent, according to
the Aplastic Anemia & MDS International Foundation Inc.
Blood transfusions from matched donors also are used to keep
blood counts high and help relieve symptoms, although they are not
an effective long-term treatment.
"Whether we cure the disease or not, patients are getting better
across the board," Maciejewski said. "We now can maintain life,
keep these patients alive longer."
More information
To learn more, visit the
Aplastic
Anemia & MDS International Foundation Inc.
