Types

Aplastic Anemia
 Disorder characterized by o
Pancytopenia o Hypoplastic marrow
Bone Marrow Failure
Acquired Bone Marrow Failure o Nt due to marrow involvement with neoplastic cells
Should not be confused with pure red cell aplasia in which anemia is the only manifestation
Myelodysplastic Syndrome
 Heterogenous group of clonal myeloid stem cells disorders
 Characterized by cytopenia
 Dysplasia of one or more cell lines
↑apoptosis more than compensatory proliferation
1.
Causes a.
Half cases are idopathic b.
Exposure to a known myelotoxic agents i.
Whole body irradiation ii.
Usage of myelotoxic drug
1.
Chloramphenicol c.
Secondary causes somehow i.
ii.
iii.
2.
3.
Alkylating agents
Antimetabolites
Predictable
Dose related
Reversible
1.
Autoreactive T lymphocytes that attacks myeloid tissues
2.
This is due to the responsiveness of pts with AA towards immunosuppressive therapy
3.
Stem cells tend to produce neoantigen through a.
Viral antigens b.
Drug-derived hapten c.
Genetic damage
4.
This neoantigen serves as a target of the T lymphocytes
1.
Usually normocytic
2.
Hypocellular of the bone marrow is the hallmark
3.
90% of intratrabeculae space occupied by fat
4.
Small foci of a.
Lympocytes b.
Plasma cells
1.
Affects all ages in both sexes
2.
Symptoms due to pancytopenia a.
Anemia i.
Weakness ii.
Palor iii.
Dypsnea b.
Thrombocytopenia i.
Petechiae ii.
Ecchymoses iii.
Ecchymoses c.
Granulocytopenia i.
Frequent persistent minor infections ii.
Sudden onset of
1.
Chills
2.
Fever
3.
Prostration
1.
Common in elderly
2.
Most cases are idiopathic
3.
Can be due to a.
Chemotherapy b.
Radiation therapy
1.
May be due to alteration in the a.
Immunological status b.
Microenvironmental factor
2.
Bone marrow develops abnormally a.
But it is not being transported into the blood stream due to vigilant quality control
1.
Anisocytosis a.
Macrocytic b.
Microcytic c.
Normocytic
2.
Plasma cells containing a network of fibers a.
Featuring stored immunoglobulin packets
3.
Hyperplastic of the bone marrow
Too many abnormally formed blood stem cells
1.
In less than a third of patients tend to develop acute leukemia
2.
Symptoms due to pancytopenia d.
Anemia i.
Weakness ii.
Palor iii.
Dypsnea e.
Thrombocytopenia f.
i.
Petechiae ii.
Ecchymoses
Neutropenia i.
Persistent infection
1.
Depends on the duration of bone marrow dysfunctionality
For Aplastic Anemia
1.
Withdrawal of drug may lead to recovery in some cases
2.
3.
4.
Poor prognosis if idiopathic form left untreated
Death due to infection secondary to neutropenia
Treatment a.
Bone marrow transplantation i.
Patient below 40 years old b.
Immunosuppression therapy i.
Older patients ii.
Lack of donor iii.
Patients underwent multiple transfusion
Congenital Bone Marrow Failure
Fanconi Anemia



Familial aplastic anemia
Characterized by o Chromosomal break o Congenital anomalies of


Thumb
Kidneys
Inherited through o X linked o Autosomal recessive
1.
Rare a.
<1/100,000 births
2.
20-25% no clinical findings
3.
Mean age of diagnosis is 7 -8 years old
1.
Autoreactive T lymphocytes that attacks myeloid tissues
2.
This is due to the responsiveness of pts with AA towards immunosuppressive therapy
3.
Stem cells tend to produce neoantigen through genetic damage
4.
This neoantigen serves as a target of the T lymphocytes
1.
Usually normocytic
2.
Hypocellular of the bone marrow is the hallmark
3.
90% of intratrabeculae space occupied by fat
4.
Small foci of a.
Lympocytes b.
Plasma cells
*same to that acquired AA
1.
Early life symptomatic aplastic anemia
2.
Clinical course same to that of acquired
AA
1.
2.
Mean survival of 19 years old
May develop into a.
Myelodysplastic b.
c.
syndrome
Acute myelobalstic leukemia
Acute lymphoblastic leukemia
3.
Later in life may develop into Squamous Cell
Carcinoma of a.
Head b.
c.
d.
Neck
Mouth
Breast

Other Types of Bone Marrow Failure
Acquired
1.
Paroxysmal Nocturnal Hemoglobinuria a.
Defective blood cells being transported into the circulation b.
Extremely rare c.
Associated with i.
Aplastic anemia ii.
Myelodysplastic syndrome d.
Stem cell mutation in PIGA i.
Lost of GPI anchor in RBCs ii.
Leads to RBC vulnerability to complement
Congenital
1.
Dyskeratosis Congenita a.
Rare b.
Different modes of inheritance c.
Ectodermal dysplasia d.
50% develop into AA in the midteen
2.
Schwachman-Diomand
3.
Cartilage-hair Hypoplasia
4.
Familial Marrow Dysfunction