Transcript Aplastic and Hypoplastic Anemias

APLASTIC AND
HYPOPLASTIC ANEMIAS
Waggas Elaas
APLASTIC ANEMIA
 Aplastic
anemia is a severe, life threatening
syndrome in which production of erythrocytes,
WBCs, and platlets has failed.
 Aplastic anemia may occur in all age groups
and both genders.
 The disease is characterized by peripheral
pancytopenia and accompanied by a
hypocellular bone marrow.

Pancytopenia : a reduction in blood count of all cell lines, WBCs, RBCs, platelets.
PATHOPHYSIOLOGY
The underlying defect in all cases appears to be a
reduction in the number of haemopoietic
pluripotential stem cells, and a fault in the
remaining stem cells or an immune reaction against
them, which makes them unable to divide and
differentiate sufficiently to populate the bone marrow

CAUSES OF APLASTIC ANAEMIA.
Primary
Secondary
Congenital
(Fanconi,s &
Non Fanconi,s
Ionizing radiation:accidental exposure (radiotherapy,
radioactive isotopes, nuclear power stations)
Idiopathic
acquired
Chemicals :benzene, organophosphates and other organic
solvents, DDT and other pesticides, organochlorines,
recreational drugs
Drugs: busulfan, chloramphenicol,
Viruses: viral hepatitis (non-A, non-B, non-C, non-G in
most cases), EBV
OTHER CAUSES OF PANCYTOPENIA
Acute leukaemia
 Megaloblastic anaemia
 Paroxysmal nocturnal haemoglobinuria (PNH)
 Myelofibrosis
 Splenomegaly
 Myeloma or lymphoma

CLINICAL FEATURES
At any age with a peak incidence around 30 years.
 A slight male predominance.
 symptoms and signs resulting from anaemia, neutropenia
or thrombocytopenia.
 Infections, particularly of the mouth and throat, are
common and generalized infections are life-threatening.
 Bruising, bleeding gums, epistaxes and menorrhagia are
frequent, and the usual presenting features, often with
symptoms of anaemia.
 The lymph nodes, liver and spleen are not enlarged.

LABORATORY FINDINGS
Anaemia is normochromic, normocytic or macrocytic
 The reticulocyte count is usually extremely low
 Leucopenia. There is a selective fall in granulocytes,
usually but not always to below 1.5 x 109/L.
In severe cases, the lymphocyte count is also low.
The neutrophils appear normal.
 Thrombocytopenia is always present and, in
severe cases, is less than 20 x 109/L.
 There are no abnormal cells in the peripheral blood.

The bone marrow is hypocellular, with loss of
haemopoietic tissue and replacement by fat which
comprises over 75% of the marrow.
The main cells present are lymphocytes and plasma cells.
Megakaryocytes in particular are severely reduced or
absent.

The disease must be distinguished from other causes
of pancytopenia.
 This is done by examination of the bone marrow
samples for Cytogenetic analysis, flow-cytometry, and
for morphology of cells and the marrow
microenviromnent.

HYPOCELLULAR BONE MARROW IN
APLASTIC ANEMIA
HYPOCELLULAR
NORMOCELLULAR
RELATED DISORDERS
1. Pure red cell aplasia
Characterized by a selective decrease in erythroid precursor cells in
the bone marrow. WBCs and platlets are unaffected.
2. Congenital dyserythropoietic anaemia.
Hereditary refractory anaemias characterized by ineffective
erythropoiesis and erythroblast multinuclearity.
3. Myelodysplastic syndromes
primary, neoplastic stem cell disorders that tend to terminate in
acute leukemia