Transcript Anemia - Shanyar

Anemia
Dr.Sana Delawer Jalal
Lecturer /Sulaimani College of Medicine/ Dept.of Pathology
M.B.Ch.B, F.I.C.M.S.
Red Cell Indices
Mean Cell Volume (MCV)
► It is calculated from PCV and red cell count as follows:
► MCV = PCV/RBC
( fl)
► Normal
value: 80-95 fl
► It decrease in iron deficiency anaemia and
haemoglopinopathies
► It is increase in megaloblastic anaemia and chronic
haemolytic anemia
Mean Cell Haemoglobin Concentration
(MCHC)
► It
is calculated from the haemoglobin and PCV as
follows:
► MCHC
► Normal
= Hb/PCV g/dl
value: 32-35.5 g/dl
► It is usually decreased in iron deficiency anaemia
(microcytic hypochromic anaemia)
Mean Cell Haemoglobin (MCH)
► It
is calculated from the haemoglobin and erythrocyte
count as follows:
► MCH
= Hbx10/RBC
► Normal
► It
pg
value: 27-32 pg
is decrease in iron deficiency anemia and
thalassaemia (microcytic hypochromic anemia)
► It is recognized by the pale colour of the red cell in the
peripheral blood film
► It is increase in macrocytic anemia (vitamin B 12 and
folic acid)
Red Cell Distribution width
(RDW)
►
RDW reflects the variation of RBCs volume
it is usually performed by modern analysers
►
Normal RDW varies between 12 to 17
►
Severe iron deficiency anemia is associated with increased RDW
►
Thalassemia and anemia of chronic disease are associated with
normal RDW
Definition
Anemia
is a decrease in the number of RBCs, Hb content,
or Hematocrit below the lower limit of the normal range for
the age and sex of the individual
►
In adults, the lower extreme of the normal haemoglobin is
taken as 13.0 g/ dl for males and 11.5 g/dl for female
►
Newborn infants have higher haemoglobin level and,
therefore, 15 g/dl is taken as the lower limit at birth
Classification of Anemia
► Several
types of classifications of anemia's have
been proposed
► Two
of the widely accepted classifications are
based on :
► The
pathophysiology
► The
morphology
The Pathophysiological Classification
Depending upon the pathophysiologic mechanism, anemias are
classified into 3 groups:
► I. Anemia due to increased blood loss.
► II.
► III.
Anemias due to impaired red cell production.
Anemias due to increased red cell destruction
.(Haemolytic )
The Morphological Classification
Based on:
1. Red cell size,
2. Haemoglobin content
3. Red cell indices
Anaemias are classified into 3 types:
►
►
►
I. Microcytic, hypochromic
II. Normocytic, normochromic
III. Macrocytic, normochromic
Simplified Classification Of
Anemias
1. Deficiency anemias
2. Aplastic anemia
3. Hemolytic anemias
4. Secondary anemias
The Pathophysiological
Classification
Impaired Red Cell Production
A. Disturbance of proliferation and differentiation of
stem cells ( aplastic anemia, pure red cell aplasia)
B. Disturbance of proliferation and maturation of
erythrocytes:
1.Defective DNA synthesis (megaloblastic anemias)
2.Defective Hb synthesis:
a/. Deficient heme synthesis (iron deficiency)
b/. .Deficient globin synthesis (thalassemia)
3. Unknown or multiple mechanisms (anemia of chronic
disease, anemia of marrow replacement)
Increased Rate Of Destruction
Intrinsic abnormalities
Hereditary
1. Red cell membrane defects (Hereditary spherocytosis,
Hereditary eliptocytosis)
2. Red cell enzyme deficiencies
a/. Glycolytic enzymes: pyruvate kinase, hexokinase
b/. Enzymes of hexose monophosphate shunt:
G-6PD, glutathione synthetase.
3. Disorders of globin synthesis
a/. Deficient globin synthesis (thalassemia)
b/. Structurally abnormal globin synthesis
(sickle cell anemia, unstable hemoglobins)
Acquired
1. Membrane defect: paroxysmal nocturnal hemoglobinuria
Increased Destruction
Extrinsic Abnormalities
1. Antibody Mediated
a/. Autoantibodies (idiopathic, drug-associated,
SLE, malignancies)
b/. Alloantibodies (transfusion reactions,
erythroblastosis fetalis)
2. Mechanical Trauma of RBCs
a/. Microangiopathic hemolytic anemias (thrombotic
thrombocytopenic purpura,hemolytic –uremic
syndrome )
b/. Cardiac traumatic hemolytic anemia
3. Chemicals and Micro organisms
4. Sequestration in mononuclear phagocytic system
- hypersplenism
Morphologic Classification Of Anemias
Type
MCV
MCHC
Common cause
____________________________________________________
►
Macrocytic anemia
Microcytic anemia
- hypochromic
- normochromic
Normocytic anemia
- normochromic
increased
decreased
decreased
or normal
normal
normal
Vitamin B12 deficiency
Folic acid deficiency
decreased
Iron deficiency
Thalassemia
normal
Spherocytosis
normal
Aplastic anemia
Chronic renal failure
Some hemolytic anemia
Microcytic
Anemia
Normocytic
Macrocytic
Classification of anemias using MCV
Iron Deficiency
Anemia
Thalassemia
Sideroblastic
Anemia
Microcytic Anemia
MCV<80 fl
Anemia of Chronic
Disorder
Lead Poisoning
Stem cells defects/
Reduced Erythropoiesis
Normocytic
Anemias
80-95 fl
Intrinsic
Hemolytic Anemias
Extrinsic Causes
Intrinsic Defects
Extrinsic
Megaloblastic anemia
Hypothyrodisim
Alcoholism
Macrocytic Anemias
MCV> 95 fl
Drugs
Myelodysplastic
syndrome
Liver Disease
Hypochromic Microcytic
Normochromic Normocytic
Laboratory Investigation
► Anemia
is not a diagnosis, but a sign of
underlying disease
► The
objective of the laboratory is to :
determine the type of anemia as an aid in
discovering the cause
Laboratory Investigation-cont.
►
Screening is usually done with the CBC or "complete blood count"
►
Most laboratories now use automated, multiparameter instruments which will provide
results for the following parameters:
►
Hemoglobin
Hematocrit
Red cell count
MCV , MCH ,MCHC
RDW
White cell and platelet count
Differentia WBC count.
►
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l
Laboratory Investigation of Hemolytic anemia
►
These are dividing into 4 groups:
I-Tests show increased red cell breakdown
II- Tests show increased red cell production
III- Tests show damage to red cells
IV- Tests show shortened red cell life span
Tests Show Increased Red Cells Breakdown
►
Serum bilirubin-unconjugated (indirect)bilirubin is raised
►
Urine Urobilinogen is raised
►
Faecal Stercobilinogen is raised
►
Serum haptoglobin ( α globulin binding protein) is reduced or
absent
►
Plasma lactic acid dehydrogenase is raised
►
Evidence of intravascular haemolysis in the form of
haemoglobinaemia, haemoglobinuria, haemosiderinuria
Tests Show Increased Red Cells Production.
►
Reticulocyte count reveals reticulocytosis which
indicate marrow erythroid hyperplasia
►
Routine blood film shows macrocytosis,
polychromasia, and normoblasts
►
Bone marrow show erythroid hyperplasia
►
X ray of bones shows evidence of expansion of
marrow spaces especially in tubular bones and skull
Tests Revealing Damages To
RBCs
►
Routine blood film shows a variety of abnormal
morphological appearances of red cells
►
Osmotic fragility is increased
►
Autohaemolysis test
►
Coomb's antiglobulin test
►
Electrophoresis for abnormal haemoglobin
►
Estimation of HbA2
Tests Show Shortened Red Cell Life Span
by Cr51 labeling method normal RBC life
span of 120 days is shortened to 20-40 days in
moderate haemolysis and 5-20 days in severe
haemolysis
► Tested
Special Investigations
► Biochemical Tests
biochemical tests are aimed to identifying:
1-Depleted cofactors necessary for normal hematopoiesis (iron,
ferritin, folate, B12).
2-Abnormally functioning enzyme (glucose-6-phosphate
dehydrogenase, pyruvate kinase), or
3-Abnormal function of the immune system (the direct antiglobulin
[Coombs'] test).
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