Transcript Aplastic anemia

Aplastic anemia
Definition
• Panctopenia with hypocellularity
• A rare and serious condition, aplastic anemia
can develop at any age, though it's most
common in younger people.
• Aplastic anemia is a condition that occurs
when the body stops producing enough new
blood cells bacause the bone marrow does
not produce sufficient new cells to replenish
blood cells including red and white blood cells
as well as platelets.
Definition
• The term 'aplastic' means the marrow suffers
from an aplasia that renders it unable to
function properly.
• Anemia refers to low red blood cell counts,
but aplastic anemia patients have lower
counts of all three blood cell types: red blood
cells, white blood cells, and platelets, termed
pancytopenia
• Aplastic anemia presents with fatigue and at
higher risk of infections and uncontrolled
bleeding.
Definition
Frequently occurs without a known cause.
• Acquired aplastic anemia is distinguished
from iatrogenic marrow aplasia, marrow
hypocellularity after intensive cytotoxic
chemotherapy for cancer.
Known causes include exposure to chemicals
(benzene, toluene in glues, insecticides,
solvents), drugs (chemotherapy, gold, seizure
medications, antibiotics, and others), viruses
(HIV, Epstein-Barr), radiation, immune
conditions (systemic lupus erythematosus,
rheumatoid arthritis), pregnancy, paroxysmal
Etiology
• 70% of aplastic anemia cases are idiopathic,
but other known causes are:
Hereditary:
o Fanconi anemia
o Dyskeratosis congenital
o Schwachman-Diamond syndrome
o Amegakaryocytic thrombocytopenia
Etiology
Acquired:
o Direct stem cell destruction
o Drugs
o Toxic chemicals
o Infection (viral, hepatitis)
o Immune disorders
o Collagen vascular diseases
Etiology
• Most cases of aplatic anemia are idiopathic,
little other than history separates these cases
from those presumed etilogy such as a drog
exposure.
• Some of these include: Radiation, chamicals,
drugs, infections, immunologic disease,
pregnancy, paroxysmal nocturnal
hemoglobinuria
Radiation
• Marrow aplasia is a major acute sequela of
radiation.
• Radiation damages DNA; tissues dependent
on active mitosis are particularly susceptible.
• Radiation dose can be approx from the rate
and degree of decline in blood counts,
dosimetry by reconstruction of exposure can
help to estimate the patient’s prognosis and
also to protect medical personnel.
Chemicals
• Benzene primarily affects the CNS and the
hematopoietic system.
• Aplastic anemia caused by bone marrow
suppression is the classic cause of death in
chronic benzene poisoning.
• The clinical and hematologic picture of
aplastic anemia resulting from benzene
exposure is not different from classical
aplastic anemia; in some cases, mild
bilirubinemia, changes in osmotic fragility,
increase in lactic dehydrogenase and fecal
urobilinogen, and occasionally some
Drugs
• Drugs which are most strongly suspected of
causing aplastic anaemia include several
drugs which are chemotherapeutic drugs,
arthritis, particularly rheumatoid arthritis
(particularly anti-inflammatory drugs which
are used in the treatment of rheumatoid
arthritis), drugs used to control overactive
thyroid, some drugs used in psychiatry and a
few antibiotics.
• For most drugs, monitoring the blood count is
not of use in preventing the disease because
of the delay between taking the drug and the
Infections
• Hepatitis is the most common preceding
infection, and posthepatitis marrow failure
accounts for about 5% of etiologies in most
series.
• Aplastic anemia can rarely follow infectious
mononuncleosis, and EBV has been found in
the marrow of a few patients, some w/o a
suggestive preceding history
Immunologic Diseases
• Aplasia is a major consequence and
inevitable cause of death in Transfusionassociated graft-versus-host disease.
• It is strongly associated with the rare
collagen vascular syndrome called
eosinophilic fascitis
• Pancytopenia with marrow hypoplasia can
also occur in SLE.
Pregnancy
• Aplastic anemia very rarely may occur
and recur during pregnancy and resolve
with delivery or with spontaneous or
induced abortion.
Paroxysmal Nocturnal
Hemoglobinuria
• Paroxysmal nocturnal hemoglobinuria (PNH),
sometimes referred to as Marchiafava-Micheli
syndrome, is a rare, acquired, potentially lifethreatening disease of the blood
characterised by complement-induced
hemolytic anemia (anemia due to destruction
of red blood cells in the bloodstream), red
urine (due to the appearance of hemoglobin
in the urine) and thrombosis