Dr Ahmad Sh Silmi IUGFaculty of Health Science 2 Objectives At The End Of This Lecture You Will Be Able To Define anemia Discuss the causes amp clinical significance of different categories of anemia ID: 909765
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1
ANEMIA & Its Laboratory Diagnosis
Dr: Ahmad Sh. SilmiIUG-Faculty of Health Science
Slide22
ObjectivesAt The End Of This Lecture You Will Be Able To:Define
anemiaDiscuss the causes & clinical significance of different categories of anemiaDescribe the classification of anemiaExplaining:Microcytic anemiaMacrocytic anemiaNormochromic
normocytic anemiaDiscuss the laboratory findings for each category of anemia
Perform basic laboratory tests for the diagnosis of anemia
Slide33
Chapter Outline1. Definition of anemias
2. Classification of anemias 2.1. Hematologic Response to Anemia2.2. Signs of Accelerated Bone Marrow Erythropoiesis2.3. Physiologic Response to Anemia 2.4. Methods of classification 2.5. Anemia Diagnosis/Cause2.6. Lab Investigation of
Anemia3. Types of anemia
3.1
microcytic hypochromic anemia
3.2
. macrocytic normocytic anemias
3.3
. normocytic anemias
3.4
. normocytic
anemias
due to
hemoglobinopathies
Slide44
1. Definition of AnemiaAnemia
is a decrease in the RBC count, Hgb and/or HCT values as compared to normal reference range for age and sex (Also determined by alteration in plasma volume)True anemia:decreased RBC mass and normal plasma volumePseudo or dilutional anemia:normal RBC mass and increased plasma volumeAn increase in plasma volume can occur in Pregnancy, volume overload (IVs) congestive heart failureLow Hgb and HCT values
Slide55
Definition of Anemia cont’d
Slide66
Anemia must also relate to the level of hemoglobin the individual normally possesses. If an adult male usually maintains a hemoglobin level of 16g/dl, and over a period of days is noted to have decreased to 14g/dl, this must be considered significant even though both values are within the normal range for an adult male.
Definition of Anemia cont’d
Slide77
Definition of Anemia cont’d…..Various diseases and disorders are associated with decreased hemoglobin levels. These include:
Nutritional deficienciesExternal or internal blood lossIncreased destruction of RBCsIneffective or decreased production of RBCsAbnormal hemoglobin synthesisBone marrow suppression by toxins, chemicals, or radiation & replacement by malignant cellsInfection
Slide88
Functionally anemia is defined as tissue hypoxia (inability of the body to supply tissue with adequate oxygen for proper metabolic function)There is an abnormal hemoglobin with an increased O2 affinity resulting in an anemia with normal or raised hemoglobin levels, hematocrit, or RBC count.
Generally anemia is not a disease, but rather the expression of an underlying disorder or disease.Definition of Anemia cont’d…..
Slide99
Anemia may develop:When RBC loss or destruction exceeds the maximal capacity of bone marrow RBC production orWhen bone marrow production is impaired
Definition of Anemia cont’d…..
Slide1010
Hematologic Response to AnemiaTissue hypoxia causes increased renal release of erythropoietin (EPO) to accelerate bone marrow erythropoiesis
The normal bone marrow can increase its activity 7-8 times normal Marrow becomes hypercellular
Slide1111
Signs of Accelerated Bone Marrow ErythropoiesisThe marrow becomes hyper-cellular due to a marked increase in RBC precursors (called erythroid hyperplasia) and the M:E ratio falls.
Nucleated RBCs may be released into the blood circulation along with the outpouring of reticulocytesNRBC number tends to correlate with the severity of anemiaIncreased Polychromasia on the Wright's- stained blood smear is seen due to increased number of circulating Retics.
Slide1212
If demand exceeds maximal bone marrow activity, RBC production may occur in extramedullary sites, liver, spleen (hepatosplenomegaly).
Slide1313
Physiologic Response to AnemiaAbility to adapt to anemia depends on:
Age and underlying disease.Cardio/pulmonary function.Rate at which anemia develops (BM can compensate easier if the onset of anemia is slow). Underlying disease.
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Clinical features:Symptoms
of hypoxia: decreased oxygen delivery to the tissues/organs causes: fatigue , faintness, weakness, dizziness, headaches, dyspnea, poor exercise tolerance, leg cramps.
Slide1515
Signs of Anemia:General signs include:pallor of mucous membrane, which occur if the
hgb concentration is less than 9g/dl, Specific signs are associated with particular types of anemia, for example, Jaundice in hemolytic anemia, leg ulcer in sickle cell anemia
Clinical
features cont’d….
Slide1616
Diagnosis of anemiaBefore making a diagnosis of anemia, one must consider:
AgeSexGeographic location
Slide1717
Diagnosis of anemia cont’d……How does one make a clinical diagnosis of anemia?
A. Patient historyDietary habitsMedicationPossible exposure to chemicals and/or toxinsDescription and duration of symptomsTiredness
Slide1818
Patient history
cont…Muscle fatigue and weaknessHeadache and vertigo (dizziness)Dyspnia (difficult or labored breathing) from exertion
G I problemsOvert signs of blood loss such as hematuria (blood in urine) or black stools
Slide1919
Diagnosis of anemia cont’d….B. Physical exam
General findingsHepato or splenomegalyHeart abnormalitiesSkin pallorSpecific findings In vitamin B12 deficiency there may be signs of malnutrition and neurological changesIn iron deficiency there may be severe pallor, a smooth tongue, and esophageal websIn hemolytic
anemias there may be jaundice due to the increased levels of bilirubin from increased RBC destruction
Slide2020
C. Lab investigationsA complete blood count, CBCRBC countHematocrit (
Hct) or packed cell volumeHemoglobin determinationRBC indices calculationReticulocyte countBlood smear examination to evaluate:PoikilocytosisLeukocytes or Platelets abnormalities
Diagnosis of anemia cont’d….
Slide2121
A bone marrow smear and biopsy to observe:Maturation of RBC and WBC seriesRatio of myeloid to erythroid
seriesAbundance of iron stores (ringed sideroblasts)Presence or absence of granulomas or tumor cellsRed to yellow ratioPresence of megakaryocytesLab investigation cont’d……
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4. Hemoglobin Electrophoresis
Diagnosis of anemia cont’d…..
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5. Antiglobulin Testing 6. Osmotic Fragility TestLab investigation cont’d……
Slide2424
Methods of Anemia ClassificationSeveral Schemes Of Classifying Anemias Exist
Morphologic Based on RBC morphologyAnemia is divided into three groups mainly on the basis of the MCV (RBC indices)Pathophysiologic Anemia is divided using three main causes/mechanisms Impaired erythrocyte formation (Aplastic anemia, IDA, Sidroblastic anemia, anemia of chronic diseases, megaloblastic anemia)Retic count is low
The bone marrow fails to respond appropriately due to disease or lack of essential supplies
Slide2525
Methods of Classification cont’dIncreased blood loss (Acute, Chronic)Retic
count is typically highAnemia results when red cell loss exceeds the bone marrow’s capacity to increase its activityIncreased destruction of RBCs (hemolytic anemias)Retic count is typically highAnemia results when red cell destruction exceeds the bone marrow’s capacity to increase its activity
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Normocytic Normochromic anemia (normal red cell indices)Blood loss anemia Hemolytic anemia
Aplastic anemiaChronic diseaesRenal insufficciency Morphologic Categories of Anemia
Slide2727
Microcytic hypochromic ( low red cell indices)Iron deficiency anemia
Sideroblastic anemiaLead poisoning ThallassemiaChronic diseases Morphologic Categories of Anemia
Slide2828
Macrocytic Normochromic ( high MCV and MCH, normal MCHC)Megaloblastic anemia
Liver diseasePost splenectomyHypothyroidismStress erythropoiesis Morphologic Categories of Anemia
Slide2929
1 Microcytic/hypochromic
2
1
3
3 Macrocytic/Normochromic
2 Normocytic/Normochromic
N.B. The nucleus of a small lymphocyte (shown by the arrow) is used as a reference to a normal red cell size
Morphologic Categories of Anemia
Slide3030
1. Microcytic- Hypochromic Anemia
Slide3131
Microcytic- Hypochromic Anemia
Many RBCs smaller than nucleus of normal lymphocytesIncreased central pallor.Includes Iron deficiency anemiaThalassemiaAnemia of chronic disease Sideroblastic anemiaLead poisoning
Slide3232
Iron
Protoporphyrin
Heme
Globin
+
Hemoglobin
Iron deficiency
Chronic inflammation or malignant
(ACD)
Thalassemia
(
or )
Sideroblastic anemia
The Cause of
Microcytic
Hypochromic
Anemia
Slide3333
RBC maturation in microcytic anemias
Normoblastic
RBC maturation
normocytic red cells
Abbott Manual
Microcytic/Hypochromic
Anemias
Normal RBC maturation is shown for comparison
Slide3434
A. Iron Deficiency Anemia (IDA) Is a condition in which the total body iron content is decreased below a normal level
This results in a reduced red blood cell and hemoglobin productionMore than half of all anemias are due to iron deficiency.
Slide3535
Iron Deficiency Anemia (IDA)Causes:Nutritional deficiency
Malabsorption (insufficient or defective absorption)Inefficient transport, storage or utilization of ironIncreased needChronic blood loss (GI bleeding, ulcer, heavy menstruation, etc)
Slide3636
DIETARY SOURCES OF IRON
Inorganic Iron eg lentils
Organic iron
eg
beef
DAILY IRON REQUIREMENT 10-15mg/day (5-10% absorbed)
Slide3737
Adult men 0.5-1
Post menopausal female 0.5-1Menstruating female 1-2Pregnant female 1.5-3Children 1.1Female (age 12-15) 1.6-2.6
Estimated daily iron requirements
Units are mg/day
Slide3838
Amount of iron in average adult
Male (g) Female (g) % of total
Hb 2.4
1.7
65
ferritin & hemosiderin
1.0
0.3
30
Myoglobin
0.15
0.12
3.5
Heme enzyme
0.02
0.15
0.5
Transferrin-bound
iron
0.004
0.003
0.1
The distribution of body iron
Slide3939
Iron Deficiency Anemia (IDA) Sequence of Iron Depletion
When iron loss or use exceeds absorption, there is a sequence of iron depletion in the body:Storage iron decreases/ low serum ferritin; serum iron & TIBC are normal, no anemia, normal red cells.
Serum iron decreases/TIBC increases (increased transferrin); no anemia, normal red cells.
Anemia
with microcytic/hypochromic red cells = IDA.
Slide4040
CLINICAL FEATURES IRON DEFICIENCYSymptoms eg.
fatigue, dizziness, headache Signs eg. pallor, Tongue atrophy/ glossitis - raw and sore, angular cheilosis (Stomatitis)
Glossitis
Angular
Cheilosis
or Stomatitis
Koilonychia
Slide4141
Clinical signs and symptomsSpoon‑shaped nails (koilonychia), brittle nails and hair.
Slide4242
Lab Investigation of IDAIron TestsUsed to differentiate microcytic hypochromic anemia's or detect iron overload (hemochromatosis)
Iron circulates bound to the transport protein transferrinTransferrin is normally ~33% saturated with ironIron Tests Include:serum iron, Total Iron Binding Capacity (TIBC), serum ferritin
Slide4343
Lab Investigation cont’dSerum iron level measures the amount of iron bound to transferrinDoes not include the free form of iron
Total Iron Binding Capacity (TIBC)Is an indirect measure of the amount of transferrin protein in the serumInversely proportional to the serum iron levelIf serum iron is decreased, total iron binding capacity of transferrin increased (transferrin has more empty space to carry iron)
Slide4444
Serum ferritin Indirectly reflects storage iron in tissues Found in trace amount in plasma It is in equilibrium with the body stores
Variation in the quantity of iron in the storing compartment is reflected by plasma ferritin concentration e.g. Plasma ferritin is decreases in IDA, Plasma ferritin increases in ACDLimitation: During infection or inflammation Serum Ferritin increases like other acute phase proteins, and then it is not an accurate indicator in such situations.
Lab Investigation cont’d
Slide4545
Bone marrow iron (Tissue iron)Tissue biopsy of bone marrowPrussian blue stain
Type of iron is hemosiderin
Slide4646
ABSENT IRON STORES IN BONE MARROW IN IRON DEFICIENCY
Iron deficiency
Normal control
Slide4747
Iron Deficiency AnemiaLab findingsLow RBC, Hgb, HctLow MCV, MCH, MCHC
Normal WBC and PLT
Blood smear
Slide4848
Iron Deficiency AnemiaRBC morphologyHypochromia
MicrocytosisAnisocytosisPoikilocytosis Pencil cells (cigar cells)Target cellsno RBC inclusionsIron parametersLow serum iron, High TIBC, Low serum ferritin
Blood smear
Slide4949
Wright’s stained blood smear
Ovalocytes
- Pencil forms No RBC inclusions
Iron Deficiency
Slide5050
B. Sideroblastic Anemia (SA)This group of anemias are characterized by:Defective protoporphyrin
synthesis (blocks) resulting in iron loadingA hypochromic anemia due to deficient hemoglobin synthesis.
Block(s
) in
protoporphyrin
synthesis leads to iron overload and microcytic/hypochromic anemia
Slide5151
Terms:Siderocytes
are mature RBCs in the blood containing iron granules called Pappenheimer bodies....abnormal.Sideroblasts are immature nucleated RBCs in the bone marrow containing small amounts of iron in the cytoplasm....normal.
Slide5252
Sideroblastic anemia is characterized by theAccumulation of iron in the mitochondria of immature nucleated RBCs in the bone marrow;
Iron forms a ring around the nucleus these are called ringed sideroblasts....abnormal. Sideroblastic Anemia (SA)
Slide5353
Lab Findings:Microcytic/hypochromic red cells, low MCV and MCHC; variable anemia, low retic.RBC inclusions: Basophilic stippling and
Pappenheimer bodies (siderocytes). (May see target cells).High serum iron and high serum ferritin (stores); low TIBC. Decreased transferrin synthesis occurs in iron overload states.Bone marrow: ringed sideroblasts (Hall mark of Sideroblastic Anemia)
Sideroblastic Anemia (SA)
Slide5454
54
RBC with iron
Wright’s stain
NRBC with iron
Prussian blue stain
NRBC with ring of iron
Prussian blue stain
Pappenheimer bodies
Blood
Bone marrow
Bone marrow
Sideroblast
Ringed Sideroblast
Sideroblastic Anemia (SA)
Slide5555
Pappenheimer bodies
Wright’s stain
Blood
Basophilic stippling/stippled RBCs
Blood
Pappenheimer bodies
Prussian blue iron stain
Blood
Sideroblastic Anemia (SA)
Slide5656
100x
Ringed Sideroblasts
Prussian blue iron stain
Bone marrow
10x
Increased stainable iron
Prussian blue iron stain
Bone marrow
Bone
marrow findings (if done):
Ringed
sideroblasts
demonstrated with Prussian blue stain.
Increased stainable iron in macrophages.
Slide5757
C. Anemia of chronic diseaseAnemia of chronic disease (ACD) – inability to use iron and decreased response to EPO Very common anemia
Associated with systemic disease, including chronic inflammatory conditions:Rheumatoid arthritisChronic renal disease Thyroid disease Malignancies Tuberculosis Chronic fungal infections etc
Slide5858
ACD pathogenesisLactoferrin is an iron biding protein in the granules of neutrophils
Its avidity for iron is grater than transferrinDuring infection or Inflammation, neutrophil-lactoferrin released into plasma and Hunts available ironBind to macrophage and liver cells (because they have receptor for lactoferrinCytokines: Produced by macrophages during inflammation and contribute to ACD by inhibiting erythropoiesis
Slide5959
Lab DiagnosisBlood findings
Early stage: normocytic normochromic.Late stage: hypochromic microcytic. LeukocytosisAbundant storage of iron in macrophage (Prussian blue)
Slide6060
60
Target cells/Codocytes
Beta
Alpha
D.
Thalassemias
Inherited decrease in alpha or beta globin chain synthesis needed for Hgb A;
quantitative
defect
All have microcytic/hypochromic RBCs and target cells
Genetic mutations classified by:
↓ beta chains = beta thalassemia…Greek/Italian
↓ alpha chains = alpha thalassemia…Asian
Slide6161
Haemoglobin
Molecule
Hgb A = 2
α
& 2
β
Hgb A
2
=
2
α
& 2
δ
Hgb F
=
2
α
& 2
γ
Consists of 4 globin chains + 4
heme
groups
Normally
, each individual inherits 2α, 1β, 1γ, and 1δ gene from
each
parent.....so 4α, 2β, 2γ, and 2δ genes are inherited.
97%
2%
1%
Slide6262
Thalassemia Impaired alpha or beta globin synthesis results in an unbalanced
number of chains produced that leads to:RBC destruction in beta Thalassemia majorProduction of compensatory Hgb types in beta thalsFormation of unstable or non-functional Hgb types in alpha thals
Slide6363
ThalassemiaSeverity ranges from lethal, to severe transfusion-dependency, to no clinical abnormalities; severity depends on the number and type of abnormal globin genes inherited.Major
severe anemia; no α (or β) chains are produced, so cannot make normal hemoglobin (s).Minor/trait mild anemia; slight decrease in normal hemoglobin types made.
Slide6464
Heinz bodies
Excess alpha chains
Supravital stain
Beta
Thal
Major (Homozygous)
Both beta genes abnormal
Marked decrease/absence of beta chains leads to alpha chain excess…no Hgb A is produced
Rigid RBCs with Heinz bodies destroyed in bone marrow and blood (ineffective erythropoiesis)
Slide6565
Stippled NRBC
NRBC
Target cell
Wright’s stained blood smear
HJB
Beta
Thal
Major (Homozygous)
CLINICAL FINDINGS
Lab Findings
Severe anemia, target cells, nucleated red cells
RBC inclusions
No hemoglobin A; compensatory Hgb F
Slide6666
Hypercellular Bone Marrow
(10x)
Pap bodies
NRBC
Transfused RBC
Target cell
Blood smear
Howell-Jolly body
Target cells
Blood smear
Transfused RBC
Beta
Thal
Major (Homozygous)
Treatment
Transfusion
Splenectomy
Iron chelation
Slide6767
Wright’s stained blood smear
Stippled RBC
Target cell
Beta
Thal
Minor (Heterozygous)
One abnormal beta gene
Slight decreased rate of beta chain production
Blood picture can look similar to iron deficiency
Lab findings
Mild anemia, target cells, no
nRBCs
, stippled RBCs
No Heinz bodies
Normal iron tests
Compensates with Hgb A2
Ovalocytes
Slide6868
Alpha Thal Major/Homozygous
Deletion of all 4 alpha genes results in complete absence of alpha chain productionNo normal hemoglobin types madeKnown as Barts Hydrops FetalisDie of hypoxia….Bart’s Hgb
Slide6969
Target cells
Wright’s stain blood smear
Heinz bodies E
xcess beta chains
Supravital stain
Alpha
Thal
Intermedia = Hgb H Disease
Three alpha genes deleted
Moderate decrease in alpha chains leads to beta chain excess…unstable Hgb H
Moderate anemia
Slide7070
Alpha Thal Minor (Heterozygous)
One or two alpha genes deleted (group)Slight decrease in alpha chain production Mild or no anemia, few target cellsEssentially normal electrophoresis; many undiagnosed
Slide7171
Beta Thalassemias
Slide7272
Alpha Thalassemias
Slide7373
+
HGB Synthesis Defects
Differential Diagnosis of Microcytic Anemia
Slide74Distinguishing features between iron def (IDA) and thalassemia Mentzer index: MCV/RBC <13 favors thalassemiaThe RBC count in thalassemia is more than 5.0 x 106
/μL (5.0 x 1012/L) and in IDA is less than 5.0 x 106/μL
(5.0 x 1012/L) MCV usually less than 70 in TT, more than 70 in IDA The red cell distribution width (RDW) in IDA is more than 17% and in TT is less than 17%.
74
Slide7575
2. Macrocytic Normocytic Anemias
Slide7676
Macrocytic Normocytic Anemias
Wright’s stained blood smear
Slide7777
A. MEGALOBLASTIC ANEMIAVitamin B12 deficiency
Folate deficiencyAbnormal metabolism of folate and vit B12B. Non megaloblastic anemiaLiver diseaseAlcoholism
Post splenoctomy
Neonatal
macrocytosis
Stress erythropoiesis
Slide7878
A. Megaloblastic Anemia
Macrocytosis due to a deficiency of vitamin B12 or folic acid that causes impaired nuclear maturation Vitamin B12 & folate are DNA coenzymes necessary for DNA synthesis and normal nuclear maturationResults in megaloblastic maturation…nucleus lags behind the cytoplasm and leads unbalanced growth called maturation asynchronyBoth deficiencies cause enlarged fragile cellsMany cells die in the marrow (ineffective)Show a similar blood picture and clinical findingsOnly vitamin B12 deficiency causes neurological
symptoms…required for myelin synthesis
Slide7979
RBC maturation in microcytic anemias…IDA
Normoblastic RBC maturation
normocytic red cells
Megaloblastic RBC maturation
macrocytic red cells
Megaloblastic
Anemia
Slide8080
Lab FindingsMild To Severe Anemia, Increased MCV & MCH, normal MCHC
Low RBC, HGB, WBC and PLT counts (fragile cells) due to ineffective hematopoiesis.Low reticulocyte count Macrocytic ovalocytes and teardrops; Marked anisocytosis and poikilocytosis Schistocytes/microcytes - due to RBC breakage upon leaving the BM Erythroid
hyperplasia - low M:E ratio (1:1) Iron stores increased.
Megaloblastic Anemia
Slide8181
Macrocytic Ovalocytes
Blood
NRBC
Blood
Howell-Jolly body
Teardrop
Schistocyte
Stippled RBC & Cabot Ring
Giant Platelet
Pap bodies
Hypersegmented Neutrophil
>5 lobes
Slide8282
Vitamin B12 deficiencyOccur as a result of one of the following conditionsNutritional Coballamin
deficiencyAbnormal intragasteric events ( i.e. inadequate proteolysis of food Coballamin)Loss or atrophy of gastric mucosa ( deficient IF)Abnormal events in the small bowel lumenInadequate pancreatic proteaseCompeting agents like fish tape worms
Slide8383
Folate (Folic acid) Deficiency: Deficient intake. Increased needs: pregnancy
, infant, rapid cellular proliferation, and cirrhosis Malabsorption (congenital and drug-induced) Inherited DNA Synthesis Disorders: Deficient thiamine and factors (e.g. enzymes) responsible for folate metabolism.
Two RBC populations
Dimorphism
Macrocytic RBCs
Microcytic RBCs
Slide8484
1. Pernicious AnemiaIt is defined as anemia resulting from defective secretion of IF associated with autoimmune attack on the gastric mucosa leading to atrophy of the stomach or abs that block IF action.
Abs block the site of if where vit b12 binds.The diagnosis is confirmed by low serum b12 level and typically abnormal results of schilling test
Slide8585
Schilling testUsed to diagnose pernicious anemia and determine if IF is available.
If absorbed a portion of oral dose of vit B12 (not used by the body) ---- excreted in urineIf not absorbed (malabsorption)…….. Not detected in urine but pass out in feces
Slide8686
Polychromatophilic
RBCs Wright’s stain
NRBC
B. Non-
Megaloblastic
Anemia
Macrocytosis
that is NOT due to vitamin B12 or folate deficiency
Accelerated erythropoiesis
Regenerating marrow or marked reticulocyte response following recent blood loss
Slide8787
Stomatocytes, Alcoholic
Echinocytes
Acanthocytes
Target cells
Non-
Megaloblastic
Anemia
Liver disease and alcoholism
Complex & multiple problems
Degree of anemia varies, round
macrocytes
Target cells/
acanthocytes
- due to abnormal lipid metabolism.
Echinocytes are also commonly found on the smear in liver disease.
Slide8888
Blood smear
Differential Diagnosis of Macrocytic Anemia
Megaloblastic
and non-
Megaloblastic
Perform B12 and folate levels
Specific morphology
Slide8989
3. Normocytic Normochromic Anemia
Slide9090
3. Normocytic Normochromic AnemiaIt includes
Aplastic anemia due to BM failureBlood loss anemia Hemolytic anemia
Is a condition in which the size & Hgb content of RBCs is normal but the number of RBCs is decreased.
Slide9191
A. Aplastic AnemiaCondition of blood pancytopenia caused by bone marrow failure…decreased production of all cell lines and replacement of marrow with fat.
Due to damaged stem cells, damaged bone marrow environment or suppressionNo extramedullary hematopoiesis
Slide9292
Types of aplastic anemiaPrimary/idiopathic = 50%
Secondary/acquired….chemicals, drugs, infections, radiation = 50%Congenital….Fanconi’s Aplasia plus dwarfism, skeletal abnormalities, mental retardation, abnormal skin pigmentation.
Slide9393
Bone marrow, decreased # precursor cells
10X
Normal RBCs No Platelets
Blood
Lab diagnosis of Aplastic Anemia
Normochromic
–Normocytic
RBC
(normal MCV & MCH)
Low
reticulocyte count & Hgb
Pancytopenia
No
abnormal cells
Hypoplasia
Bone marrow
Normal Serum iron, vitamin B12 and folate levels
Slide9494
B. Hemolytic anemia Result from an increase in the rate of pre mature red cell destruction. Compensated hemolytic disease
Uncompensated hemolytic diseaseIt leads toErythropoietic hyperplasia BM produces red cells 6 to 8X the normal rateMarked reticulocytosis
Slide9595
Two main mechanisms for RBC destruction in HAIntravascular hemolysis: in the circulationExtravascular hemolysis: in RE system (reticuloendothelial system)
B. Hemolytic anemia
Slide9696
Extravascular hemolysisAged RBC 120 dayAbnormal RBC
During destruction RBC releases Hgb Hgb
Exstravascularly
removed
by Macrophage (RES)
in BM, liver and spleen
Iron
reabsorbed
Globin
Amino acid
Protein synthesis
Protoporphyrin
Unconjugated bilirubin
liver (glucuronic acid)
conjugated bilirubin
gut reabsorbed &
Excreted as
urobilin
& urobilinogen
97
Extravascular hemolysisLab Features Increased RBC break down
Serum bilirubin increaseStool urobilinogen increaseBlood urobilinogen increaseUrine urobilinogen increase
Slide9898
Intravascular hemolysis Red cells are destroyed in blood vessels and Hgb is released into the circulation:
Free Hgb
Saturates plasma
haptoglobin
Excess free Hgb is filtered by the
glomerules
(kidney)
(if rate of hemolysis saturates renal reabsorption capacity)
Free Hgb enters urine
Fe is released in bladder tubule
Renal tubule loaded with hemosiderin
Slide9999
Intravascular hemolysisLab FeaturesHemoglobinemia and hemoglobinuria
Hemosiderin uriaReduced/absent serum haptoglobin
Slide100100
1. Hereditary hemolytic anemiaThis is a congenital hemolytic anemia. some of which present at birth and other later in life, while still others may remain silent unless a physiological stress is super imposed
Result of intrinsic red cell defects Membrane defect (Hereditary Shperocytosis, Elliptocytosis and sickle cell anemia)Metabolic defect : G6PDH and PK defic Hgb chain defect (
hemoglobinopatheis) : sickle cell anemia
Slide101101
Spherocytes
A. Hemolytic
Anemias
due to Membrane Defects
Most common is Hereditary Spherocytosis (HS)
Membrane defect is decreased
spectrin
and increased permeability of membrane to sodium ions
Lab findings
Anemia varies
Few to many
spherocytes
on smear, high MCHC
Increased OF test
Slide102102
H Ovalocytosis
Normocytic ovalocytes
H.
Ovalocytosis
/
Elliptocytosis
Membrane defect is polarization of cholesterol or hemoglobin at ends and increased sodium permeability
Over 25%
ovalocytes
Most asymptomatic
Mild anemia in 10-15%
Slide103103
H Stomatocytosis
Hereditary Stomatocytosis
Membrane defect is abnormal permeability to sodium and potassium
Caused by edema
20-30%
stomatocytes
on blood smear
Mild to severe hemolytic anemia
Slide104104
H Acanthocytosis = Abetalipoproteinemia
Hereditary
Acanthocytosis
Defect is increased membrane cholesterol due to abnormal plasma lipids
Numerous
acanthocytes
on smear
Mild anemia
Also known as
abetalipoproteinemia
Slide105105
PK Deficiency
Echinocytes
PK deficiency
↓ATP impairs
cation
pump
Severe hemolytic anemia
Echinocytes
G-6-PD Deficiency
Unable to protect Hgb due to decreased NADPH
No clinical problems unless exposed to oxidants
Exposure to oxidants induce Heinz body formation and RBC destruction
Normal RBCs
if no exposure to oxidant
G-6-PD Deficiency
B. Hemolytic Anemias due to Enzyme Defects
Slide106106
G-6-PD deficiency after exposure to oxidant
Heinz bodies -
denatured Hgb
Supravital
stain
G-6-PD deficiency Hemolytic episode
Damaged RBCs Wright’s stain
G-6-PD Deficiency
Blood findings after oxidant exposure:
Mod to severe anemia
Schistocytes
,
spherocytes
due to pitting out of Heinz bodies by spleen
Enzyme assay
Slide107107
Target cells/Codocytes
C. Normocytic
anemias
due to
hemoglobinopathies
Inherited hemoglobin defect with production of structurally abnormal globin chains;
All have target cells
Beta chain amino acid substitution = variant Hgb
Hgb S = valine substituted for glutamic acid @ 6th of ß
Hgb C = lysine substituted for glutamic acid @ 6th of ß
Slide108108
HGB S Disease (Hgb SS)
Sickle cell
Target cell
Hemoglobin S Disorders
Two sickle cell genes inherited (both beta chains are abnormal)
Symptomatic after 6 months of age
Lab findings
Severe anemia
Targets, sickle cells
NRBCs, inclusions
No Hgb A, >80% Hgb S, ↑ F
A.
Hemoglobin S disease/Sickle cell anemia/
Hgb
SS
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Target cells only
NO Sickle cells
HGB S Trait (Hgb SA)
Hemoglobin S Disorders
One sickle cell gene inherited
Lab Findings
Asymptomatic, targets only
No anemia or sickle cells
~60% Hgb A, ~40% Hgb S
Potential problems if hypoxic
B. Hemoglobin S trait/Sickle cell trait/
Hgb
SA
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C crystals
HGB C Disease (Hgb CC)
Target cell
Hemoglobin C Disorders
Lab findings
Mild anemia
Many target cells
Intracellular C crystals
No Hgb A, >90% Hgb C
Decreased OF
A.
Hemoglobin C disease/
Hgb
CC
Two C genes inherited (
both β chains are abnormal)
C crystals polymerize differently and look like blocky Hgb packed rods
in
the red cells....intracellular
.
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HGB C Trait (Hgb CA)
Target cells only
NO C crystals
Hemoglobin C Disorders
B.
Hemoglobin C trait/
Hgb
CA
One C gene inherited
Lab findings
Asymptomatic, no anemia
Targets, no C crystals
~60% Hgb A, ~40% Hgb C
Normal Hgb A2 and F
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SC Crystals
Target cells
HGB SC Disease (Hgb S & Hgb C)
Hemoglobin SC Disease
Lab findings
Intermediate in severity between Hgb SS & SA
Several target cells
Many SC crystals
No Hgb A, ~50% Hgb S, ~50% Hgb C, ↑ F
Hemoglobin SC disease/
Hgb
SC
One sickle gene and one C gene inherited
Double heterozygote‑ inherit sickle gene (S) from one parent and C gene from other parent;
Both β chains are abnormal
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2. Acquired hemolytic anemiaA variety of acquired conditions result in shortened survival of previously normal red cells. These include immune mediated destruction, red cell fragmentation disorders, acquired membrane defects, spleen effects
Result of extrinsic causesImmune HA; warm HIHA, cold AIHADrug associatedInfection associated
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Spherocytes & polychromasia
Blood
Warm Autoimmune HA (WAIHA)
Altered immune response causes production of an
IgG
warm autoantibody against ‘self’ RBC antigens
Antibody/complement attaches to RBC antigen…partially
phagocytosed
(loss of membrane)
spherocytes
Cause
:
Primary (idiopathic) or secondary to disease
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Ingestion of coated RBC
RBC
Electron Microscopy
Blood
Monocyte with ingested RBC
RBC
Warm Autoimmune HA (WAIHA)
Lab findings
Mod to severe anemia,
spherocytes
, high MCHC
Erythrophagocytosis
Looks similar to H spherocytosis but positive DAT
Increased OF, bilirubin
Erythroid hyperplasia
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50x
RBC Agglutination
100x
Cold Autoimmune HA (CAIHA)
Altered immune response causes production of an
IgM
cold autoantibody against ‘self’ RBC antigens
Antibody/C3 attaches to RBC antigen agglutination (
lysis
by complement or macrophage)
Primary (idiopathic) or secondary to disease
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Cold Autoimmune HA (CAIHA)Lab findingsAgglutination of red cells in extremities....ears, toes, nose
tissue damage gangre Severity varies with seasons….avoid the coldIgM antibodies cause RBC agglutinationReticulocytosisPositive Direct Antiglobulin
Test (detects complement)
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Hemolytic Transfusion ReactionIncompatible blood transfusionRecipient has antibodies to antigens on the donor red cells received
Donor cells are destroyedABO worstIntravascular hemolysis that is complement-induced lysis…immediateCan be life-threatening
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Hemolytic Disease of the Newborn Caused by maternal IgG
antibodies directed against baby RBC antigensAntibodies cross placenta and destroy fetal red cellsHDN due to Rh incompatibilityRh negative mother forms Rh antibody after exposureHDN due to RhSever anemiaMany nucleated red cellsHDN due to ABO incompatibility Mother’s ABO blood type is O; baby is type A or B
HDN due to ABOMild, no anemia
Spherocytosis
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Schistocytes
Fibrin Strands
RBC
RBC fragmentation on fibrin strands
Hemolytic
Anemias
due to Trauma
Fragmentation syndromes…most common finding on smear are
schistocytes
; anemia varies
Types of trauma
Mechanical…prosthetic heart valves/cardiac abnormalities
Microangiopathic
(MAHA)…small vessels (DIC.........bleeding)
March
hemoglobinuria
…forceful contact….
Schistocytes
121
Schistocytes
& Spherocytes
Hemolytic
Anemias
due to Infectious Agents, and Thermal Burns
Anemia varies, with severe hemolysis
Schistocytes
and
spherocytes
on blood smear
Parasitize RBC, elaborate lytic toxins or cause direct damage to red cell membrane
Malaria fever
Closteridal
infections..release
toxins
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END OF ANEMIA