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anemia
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HEMATOLOGY LECTUREAnemias(Chapter 19 of Rodak’s Hematology) /sqg
- decrease in oxygen carrying capacity of blood caused by decrease in RBCs, Hgb and Hct
- classic symptoms are fatigue and shortness of breatho patient history and physical examination are
important preliminary components of diagnosis- physiological adaptations occur due to anemia
o in acute blood loss blood flow is redirected to the brain, heart
and muscleso in chronic blood loss
↑ in 2,3-BPG to increase delivery of O2 to tissues
↑ in EPO
MECHANISMS OF ANEMIA- ineffective erythropoiesis
o production of defective erythroid precursor cellso causes cell to undergo apoptosis before
maturationo body ↑ EPO to compensate
useless if precursors are still defectiveo RBC circulating in blood is low
- inefficient erythropoiesiso decrease in number of erythroid precursor cellso associated with ↓ iron, ↓ EPO, ↓ of cells due to
autoimmune reaction, infection by parvovirus B19, and infiltration of bone marrow with granulomas and malignant cells
o RBC production is low- chronic blood loss
o induces iron deficiency- acute blood loss
o slow production of RBCs by bone marrow
LAB DIAGNOSIS OF ANEMIA- complete blood count (CBC) - routine
o RBC counto MCV
Hct x 10RBC count
reference range: 80-100 fLo MCH
Hgb x 10RBC count
reference range: 26-32 pgo MCHC
Hgb x 100Hct
reference range: 32-36 g/dLo RDW (in automated analyzers only)
- reticulocyte count – must be performed in every patient suspected with anemiao absolute reticulocyte count
retic100
x RBC count
reference range: 20-115 x 109/Lo corrected reticulocyte count
retic x Hct45
o reticulocyte production index better indication than corrected retic count
corrected retic countmaturation time
o reticulocyte counts determine the cause of anemia
o ↑ retics hemolytic anemia acute blood loss
o ↓ retics chronic blood loss insufficient/ineffective erythropoiesis
- peripheral blood film examination – describes size, shape, variations and inclusions of RBCs
RBC ABNORMALITIESAbnormality Appearance Associated Diseasemacrocyte macrocytic anemiasmicrocyte microcytic anemias
spherocytehereditary spherocytosis,
immune hemolytic anemia
elliptocytehereditary
elliptocytosis/ovalcytosis, IDA, thalassemia,
myelophthisic anemiaovalocyte
stomatocytehereditary
stomatocytosis, Rh deficiency
sickle cellsickle-cell anemia, sickle-
cell-beta-thalassemia
Hb C crystal Hb C disease
Hb SC crystal
Hb SC disease
target cell (codocyte)
hemoglobinopathies, thalassemia
schistocytemicroangiopathic hemolytic anemia
helmet cell (keratocyte)
acanthocytespur cell anemia,
neuroacanthocytosis
Burr cell (echinocyte)
uremia, pyruvate kinase deficiency
Teardrop cell
(dacryocyte)
primary myelofibrosis, myelophthisic anemia,
thalassemia, megaloblastic anemia
RBC INCLUSIONS
Inclusion CompositionAssociated
DiseaseDiffuse
basophiliaRNA hemolytic anemia
basophilic stippling
precipitated RNA
lead poisoning, thalassemia,
hemoglobinopathies, megaloblastic
anemia, myelodysplastic
anemias
Howell-Jolly body
DNA
megaloblastic anemia, hemolytic
anemia, thalassemia,
myelodysplastic anemia
Heinz body denatured Hgb G6PD deficiency
Pappenheimer bodies
iron
sideroblastic anemia,
hemoglobinopathies, thalassemias,
megaloblastic and myelodysplastic
anemias
Cabot ringmitotic spindle
remnants
megaloblastic anemia,
myelodysplastic anemia
Hb Hprecipitated β-globin chains
Hb H disease
CLASSIFICATION OF ANEMIAS ACCORDING TO MCV
1. Microcytic Anemias (MCV < 80 fL)o sideroblastic anemiao iron deficiency anemiao anemia of chronic inflammationo thalassemia
2. Macrocytic Anemias (MCV > 100 fL)o Nonmegaloblastic anemias
aplastic anemia chronic liver disease alcoholism
o Megaloblastic anemia vitamin B12 deficiency folate deficiency
3. Normocytic Anemias (MCV 80-100 fL)o ↑ Reticulocyte Count
acute blood loss hemolytic anemias
o Normal or ↓ Reticulocyte Count aplastic anemia anemia of renal disease myelophthisic anemia parvovirus B19 infection anemia of chronic inflammation
CLASSIFICATION OF ANEMIAS ACCORDING TO PATHOPHYSIOLOGY1. Anemia by Decreased RBC Production
o HSC failure aplastic anemia
o disruption of DNA synthesis megaloblastic anemia
o disruption of Hgb synthesis iron deficiency anemia thalassemia sideroblastic anemia anemia of chronic inflammation
o disruption of erythroid precursor proliferation anemia of renal failure anemia of marrow infiltration
2. Anemia by Increased RBC Destructiono membrane defects
hereditary spherocytosis hereditary elliptocytosis
o enzyme deficiency G6PD deficiency pyruvate kinase deficiency
o globin abnormality sickle cell anemia hemoglobinopathies
o immune causes warm-type autoimmune hemolytic anemia paroxysmal cold hemoglobinuria cold agglutinin disease hemolytic transfusion reaction hemolytic disease of the newborn
o non-immune causes microangiopathic hemolytic anemias
(thrombotic thrombocytopenic purpura, hemolytic uremic syndrome, HELLP syndrome)
macroangiopathic hemolytic anemia
infection (malaria, babesiosis)o blood loss
acute blood loss anemia