Definition :
Reduction in hemopoietic tissue (not a consequence of bone marrow fibrosis or infilteration ),
resulting in peripheral blood cytopenia .
Basic features:
There are two fundamentall different types :
1predictable,often reversible hypoplasia:
a) Usually a consequence of ionizing radiation and / or cytotoxic drugs, dose dependent
b) Affecting the rapidly dividing maturing hematopoietic cells rather than the
pluripotent cells .
c) Repeated or prolonged therapy may deplete the sten cells.
2Unpredictaple,
often ivrreversible hypoplasia:
a) Primary "idiopathic" or secondry to an idiosyncratic reaction to drugs or viral
infections.
b) Mainly due to hematopoietic stem cell defect / damage .
c) Sometimes related to an autoimmune or changes in the microenvironment of stem cells.
Pathogenesis:
1Reduction in hematopoietic tissue and increase in fat spaces of the marrow.
2Deficient cell production, usually reflected firstly on granulocyte and platelet counts.
3Typically development of pancytopenia.
Associations:
a) Drug ingestuion (other than anticancer drugs):
1Antibiotic: chloramphanicol, sulphonanides.
2Antiinflammatory : phenylbutazone, gold.
3Antiepileptic : hydantion.
4Antidiabetic : chlorporpamide,tolbutamide.
5Antithyroid
6Psychotropic
b) Exposure to chemicals:
1Hydrocerbonsbenzene.
2Insectsides.
3Infection:
1Viral: specially viral hepatitis(autoimmune reaction).
2Bacterial: mainly tyberculosis.
Laboratory investigations:
a) Hematological:
(1) CBC:
Normocytic
normochromic anemia.
Granylosytopenia (< 1.5 X 10 9 /L).
Reticulocytopenia
(2) Bone marrow (aspiration and biopsy):
May reveal blood tap.
Hypocellular,widening of fat spaces.
Iron srores are increased especially in multitransfused patients.
(3) Hb F may be increased
(4) Plasma iron often increased, TIBC is normal or decreased and % saturation is increased.
(5) Plasma 55 Fe clearance is prolonged and utilization for Hb synthesis is reduced.
Course and prognasis:
3 of cases: Rapid progression to death .
3 of cases: Chronic cytopenia →death within a year
3Spontaneous partial or complete remission.
· Hereditary, autosomal recessive.
· Anemia is macrocytic, presenting before the age of 5years
· Associated with cytogenetic anomalies e.g. skeletal defects, skin pigmentation.
· Poor prognosis.
2Associated with paroxysmal nocturnal Hemoglobinuria (PNH)
· PNH usually develops a variable time ofter marrow hypoplasia due to emergence of
mutant stem cell clone.
· Alternatively, an episode of hypoplasia may occur in a patient who has PNH with
hemolysis.
3Red cell aplasia:
Selective depression of the erythroid series.
a) Blackfan –Diamond syndrome:
· Congenital, macrocytic anemia.
· Present typically within the first year.
· Spontantaneous remission, responds to corticosteroids.
b) Acquired:
i) Acuteaplastic
crisisin hemolytic anemia and postinfection, may respond to folic acid.
ii) Chronic ·
Majority assoicated with thymoma or SLE.
Reduction in hemopoietic tissue (not a consequence of bone marrow fibrosis or infilteration ),
resulting in peripheral blood cytopenia .
Basic features:
There are two fundamentall different types :
1predictable,often reversible hypoplasia:
a) Usually a consequence of ionizing radiation and / or cytotoxic drugs, dose dependent
b) Affecting the rapidly dividing maturing hematopoietic cells rather than the
pluripotent cells .
c) Repeated or prolonged therapy may deplete the sten cells.
2Unpredictaple,
often ivrreversible hypoplasia:
a) Primary "idiopathic" or secondry to an idiosyncratic reaction to drugs or viral
infections.
b) Mainly due to hematopoietic stem cell defect / damage .
c) Sometimes related to an autoimmune or changes in the microenvironment of stem cells.
Pathogenesis:
1Reduction in hematopoietic tissue and increase in fat spaces of the marrow.
2Deficient cell production, usually reflected firstly on granulocyte and platelet counts.
3Typically development of pancytopenia.
Associations:
a) Drug ingestuion (other than anticancer drugs):
1Antibiotic: chloramphanicol, sulphonanides.
2Antiinflammatory : phenylbutazone, gold.
3Antiepileptic : hydantion.
4Antidiabetic : chlorporpamide,tolbutamide.
5Antithyroid
6Psychotropic
b) Exposure to chemicals:
1Hydrocerbonsbenzene.
2Insectsides.
3Infection:
1Viral: specially viral hepatitis(autoimmune reaction).
2Bacterial: mainly tyberculosis.
Laboratory investigations:
a) Hematological:
(1) CBC:
Normocytic
normochromic anemia.
Granylosytopenia (< 1.5 X 10 9 /L).
Reticulocytopenia
(2) Bone marrow (aspiration and biopsy):
May reveal blood tap.
Hypocellular,widening of fat spaces.
Iron srores are increased especially in multitransfused patients.
(3) Hb F may be increased
(4) Plasma iron often increased, TIBC is normal or decreased and % saturation is increased.
(5) Plasma 55 Fe clearance is prolonged and utilization for Hb synthesis is reduced.
Course and prognasis:
3 of cases: Rapid progression to death .
3 of cases: Chronic cytopenia →death within a year
3Spontaneous partial or complete remission.
Special Types of Aphasia
1Fanconi's anemia:· Hereditary, autosomal recessive.
· Anemia is macrocytic, presenting before the age of 5years
· Associated with cytogenetic anomalies e.g. skeletal defects, skin pigmentation.
· Poor prognosis.
2Associated with paroxysmal nocturnal Hemoglobinuria (PNH)
· PNH usually develops a variable time ofter marrow hypoplasia due to emergence of
mutant stem cell clone.
· Alternatively, an episode of hypoplasia may occur in a patient who has PNH with
hemolysis.
3Red cell aplasia:
Selective depression of the erythroid series.
a) Blackfan –Diamond syndrome:
· Congenital, macrocytic anemia.
· Present typically within the first year.
· Spontantaneous remission, responds to corticosteroids.
b) Acquired:
i) Acuteaplastic
crisisin hemolytic anemia and postinfection, may respond to folic acid.
ii) Chronic ·
Majority assoicated with thymoma or SLE.
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