MLAB 1315-Hematology Fall 2007 Keri Brophy
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Transcript MLAB 1315-Hematology Fall 2007 Keri Brophy
MLAB 1415-Hematology
Keri Brophy-Martinez
Chapter 13: Hypoproliferative
Anemias
Overview
Disorders
Anemia
Acquired
Congenital
Normocytic or Macrocytic
Normochromic
Bone marrow hypocellularity
Defect
Depletion, damage or inhibition of stem and/or
progenitor cells
APLASTIC ANEMIA
Aplastic anemia
Disorder (or group of disorders) characterized
by aplasia of bone marrow or its destruction by
chemical agents or physical factors. All cell
lines are affected.
Aplasia
Failure of a tissue or organ to develop
normally
Pathophysiology
Aplastic anemia is caused by an immune
process, either antibodies directed against
the stem cell or a cellular immune
mechanism (T-lymphocyte) that
suppresses stem cell prolieferation
Bone marrow fails due to the
immunologically mediated tissue-specific
destruction
Phases
I: Onset
After an initiating event (i.e. viral infection)
the hematopoietic compartment is destroyed
by the immune system
Small numbers of surviving stem cells can
support adequate hematopoiesis for some
time, but eventually the circulating cell counts
become very low and clinical symptoms appear
Phases
II: Recovery
Either a partial response or a complete response can
occur, initially, without increased number of stem cells
III: Late Disease
Years after recovery, blood counts may fall as
pancytopenia occurs or as abnormal clones of stem cells
emerge.
Often leads to PNH( paroxysmal noctural
hemoglobinuria), AML (acute myelogenous leukemia) or
MDS (myelodysplasia)
Aplastic Anemia
Two Groups
Acquired
Surface after age 60
Congenital
2-5 years old
15-25 years old
APLASTIC ANEMIA
Acquired
Idiopathic or primary with no clear cause
Secondary due to
Chemical agents such as benzene, insecticides, weed killers
Drugs such as chloramphenicol (antibiotic) and
phenylbutazone (anti-inflammatory), chemotherapy drugs
(busulfan, vincristine), anticonvulsants (Dilantin)
Ionizing radiation from nuclear fallout, x-rays or radiation
therapy, radium
Infections such as hepatitis, Epstein-Barr virus, CMV, HIV
Miscellaneous - pregnancy, malnutrition, immunologic
dysfunction
APLASTIC ANEMIA
Congenital/ Constitutional Aplastic Anemia
Fanconi’s anemia
Genetic predisposition to bone marrow
failure
Chromosomal breaks, gaps, exchanges
25- 30% cases of childhood aplastic anemia
Twice as common in males than females
Clinical Features
Low birth weight
Skin
hyperpigmentation
Short statue
Dyspnea
Bleeding
Infections
Skeletal disorders
Aplastic anemia
: Lab Features
Total Bone marrow failure
Hypocellular: 70% fat
Pancytopenia= all cell lines affected
Aplastic Anemia:
Lab Features
↓ RBC, hgb (<7), hct (<20), retic (absolute and corrected)
↓ WBC (<1.5) , absolute neutrophil count (<0.5)
Relative lymphocytosis due to the neutropenia
↓ platelets (<20,000-60,000)
P.B
Normocytic,normochromic
Moderate anisocytosis, poikilocytosis
NRBCs, teardrops*
Treatment
Treatment of choice is bone marrow
transplantation. If this is not an option,
immunotherapy is given. Spontaneous
recovery may occur if the offending agent
is removed.
Prognosis is poor, high mortality rate..2
years
Complications include
Bleeding
Iron overload due to transfusions
Pure red cell aplasia
Rare
condition
Red cell precursors in the bone
marrow are decreased
Presence of peripheral blood anemia
Pure Red Cell Aplasia
Congenital
Diamond-Blackfan anemia
Defect in BFU-E and CFU-E
Acquired
Hemolytic crises
Infection with parvovirus, EBV, viral hepatitis
Malnutrition
Certain drugs or neoplasms
Other Hypoproliferative Anemias
Defective hormonal stimulation of
erythroid progenitor cells
Renal Disease
Endocrine Disorders
Lab findings reflect anemia and
pathologies of primary disorder
References
•
•
Harmening, D. M. (2009). Clinical Hematology and
Fundamentals of Hemostasis. Philadelphia: F.A Davis.
http://www.aamdsglossary.co.uk/glossary/b
http://blass.com.au/definitions/aplastic%20anemia
McKenzie, S. B., & Williams, J. L. (2010). Clinical
Laboratory Hematology . Upper Saddle River: Pearson
Education, Inc.