hematology lectures 2011

8/9/2019 Hematology Lectures 2011

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Objectives

1.

Quick revision of the physiology of normal haematopoiesis.2.

Define the term anaemia, its pathophysiology

and diagnostic

approach..

3.

List the common causes and symptoms of iron-deficiencyanaemia. State how iron deficiency anaemia

may be treated.

4.

Define the terms megaloblastic

anaemia

and anaemia

of chronic

diseases. In each case discuss their causes, consequences and

management.

5.

Define the terms aplastic

anaemia

and myelodysplasticsyndrome. In each case an over view of clinical features,

diagnosis and treatment is outlined.

6.

Define the term haemolytic

anaemia

including thalassaemia andsickle cell anaemia, and discuss the clinical features, diagnosis

and treatment.


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HematopoiesisHematopoiesis

Hierarchical model of lymphohematopoiesis. RBC-red blood cell; NK cell-natural killer cell


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Erythroid

maturation sequence: As proliferationparameters (i.e., rates of DNA and RNA synthesis) and cell

size decrease, accumulation of erythroid-specific proteins

(i.e., heme and globin) increases, and the cells adapt theircharacteristic morphology.


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**HematopoieticHematopoietic

CytokinesCytokines

11--

Stem cell Factor.Stem cell Factor.

22--

ILIL--2, IL2, IL--3, IL3, IL--4, IL4, IL--5, IL5, IL--6, IL6, IL--7, IL7, IL--9.9.

33--

GG--CSF.CSF.

44--GMGM--CSF.CSF.

55--Erythropoietin.Erythropoietin.

66--Thrombopoietin.Thrombopoietin.

77--OthersOthers

**GlycoproteinsGlycoproteins

that act on cell surface receptors .Initiate complex Secondthat act on cell surface receptors .Initiate complex Secondmessenger and transcriptional and postmessenger and transcriptional and post--transcriptional regulation.transcriptional regulation.


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AnemiaAnemia

DEFINITIONDEFINITION::

Reduction in the number of erythrocytes,Reduction in the number of erythrocytes,or hemoglobin concentration ,or packedor hemoglobin concentration ,or packed

cell volume (PCV) value below lowercell volume (PCV) value below lowernormal limit for age and sex.normal limit for age and sex.

**Anemia is not a disease, it is rather a manifestation ofAnemia is not a disease, it is rather a manifestation ofdifferent diseases.different diseases.
http://127.0.0.1:83/content/13/13159t01.htm


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NORMAL VALUES FOR RED BLOOD CELLNORMAL VALUES FOR RED BLOOD CELL

(INDICES)(INDICES)MEASUREMENTSMEASUREMENTS

NORMAL RANGENORMAL RANGE

(APPROXIMATE)(APPROXIMATE)UNITSUNITSMEASUREMENTMEASUREMENT

Adult Males: 13Adult Males: 131818

Adult Females: 12Adult Females: 121616g/dLg/dLHemoglobinHemoglobin

Adult Males: 40Adult Males: 405454Adult Females: 37Adult Females: 374747

%%HematocritHematocrit

(PCV)(PCV)

Males: 4.5Males: 4.5

66

Females: 4Females: 4

5.45.4

X 10X 101212/ L/ LRed blood cell (RBC) countRed blood cell (RBC) count

7878

9898fLfLMean cell volume (MCV)Mean cell volume (MCV)

3030

3434g/dLg/dLMean cell hemoglobin concentrationMean cell hemoglobin concentration

(MCHC(MCHC))3030

3636pgpgMean cell hemoglobin (MCHMean cell hemoglobin (MCH))

4000040000 --

100000100000// LL

of bloodof bloodReticulocyteReticulocyte

count (absolute number)count (absolute number)

0.50.5

1.51.5% of RBC% of RBCReticulocyteReticulocyte

percentagepercentage
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Etiology Of AnemiaEtiology Of Anemia

11--

Decreased Production of RBC/HemoglobinDecreased Production of RBC/Hemoglobin

((HypoproliferativeHypoproliferative

AnemiaAnemia).).

22--

Increased Destruction ofIncreased Destruction of RBC(RBC(HemolysisHemolysis).).

33--

Blood Loss.Blood Loss.

44--

Sequestration.Sequestration.


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Effects of AnemiaEffects of Anemia

Physiological:Physiological:

due to tissue hypoxia.due to tissue hypoxia.

11--Increased 2,3 DPG inIncreased 2,3 DPG in RBC(helpsRBC(helps

to deliver more oxygen toto deliver more oxygen totissues).tissues).

22--Increased Cardiac Output (heart rate and stroke volume).Increased Cardiac Output (heart rate and stroke volume).

33--Redistribution of Blood Flow to vital organs.Redistribution of Blood Flow to vital organs.

Clinical:Clinical:

11--Pallor of the skin and mucous membranes.Pallor of the skin and mucous membranes.22--Easy Fatigability due to muscle hypoxia.Easy Fatigability due to muscle hypoxia.

33--Cardiovascular: dizziness, SOB, worsening of IHD and HF.Cardiovascular: dizziness, SOB, worsening of IHD and HF.

44--Loss of Concentration due to brain hypoxia.Loss of Concentration due to brain hypoxia.55--Other effects.Other effects.


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Approach To Anemia

1. History

Bleeding source specially GI and genital.

Drugs e.g. Aspirin, NSAIDs,sulfa

drugs,chloramphenicol

etc...

Family history of anemia,blood

transfusion and ethnicbackground.

Diet.

Chronic diarrhoea.

Recent pregnancy.

Weight loss and anorexia.

SymptomsGeneral: fatigue, malaise, weakness.

CVS: palpitations, syncope, dyspnea.

Neurological: headache, vertigo, tinnitus, numbness

T


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Approach To Anemia2. Physical Examination

CVS: tachycardia, systolic flow murmur, wide pulse pressure,evidence

of CHF.

Pallor: mucous membranes, conjunctiva (Hb

< 9g/dl), skin creases(Hb

< 7g/dl).

Splenomegaly; seen in different hematological and non hematological

conditions.

Lymphadenopathy,bleeding

spots.

Rectal (occult blood).

Others

Koilonychia

(spoon-shaped nails)and

Glossitis

as in iron deficiencyanemia,

Neurological findings as in pernicious anemia and vitamin B6deficiency.

Jaundice as in hemolytic anemia

3. Complete Blood Counts and Blood Film

Hemoglobin level, WBC count and differential, platelet count, bloodfilm morphology, reticulocyte

count and percentage, RBC indices.

Di i f A i


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Diagnosis of AnemiaDiagnosis of Anemia


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CLINICAL APPROACH TO ANEMIA (continue)

High ReticulocytesLow or Normal Reticulocytes

Treated iron deficiency

Thalassemia

major

Hypochromic Microcytic(mean red cell volume MCV < 76)

Iron deficiency

Thalassemia

minor

Sideroblastic

anemia

Lead poisoning

Chronic disease

Hemolytic anemia

Post hemorrhagic anemia

Normochromic Normocytic(MCV 76

96 )

Chronic disease

Liver disease

Uremia

Endocrine disorders (hypo/hyperthyroid, addisons)

Connective tissue diseases

Primary bone marrow abnormalities

Myelodysplasia

Marrow Infiltration (leukemia, myeloma, infection)

Myelofibrosis

Aplasia

TreatedTreatedvitvit

B12 orB12 or folatefolate

deficiencydeficiency

Macrocytic/Megaloblastic(MCV > 96 )

Megaloblastic

low vit

B12

low Folate

Drugs (MTX, cyclophosphamide

,arsenic)

Macrocytic

Hypothyroidism

Hypoplastic

marrow, aplasia

Liver disease Alcohol


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RED BLOOD CELL MORPHOLOGY AS A CLUE TO THE DIAGNOSIS OF ANEMIASRED BLOOD CELL MORPHOLOGY AS A CLUE TO THE DIAGNOSIS OF ANEMIAS

REPRESENTATIVE CAUSES OF ANEMIAREPRESENTATIVE CAUSES OF ANEMIARBC MORPHOLOGYRBC MORPHOLOGY

Iron deficiency, anemia of chronic disease,Iron deficiency, anemia of chronic disease, thalassemiathalassemia, and (rarely) lead, and (rarely) lead

poisoning, vitamin B6 deficiency, or hereditarypoisoning, vitamin B6 deficiency, or hereditary sideroblasticsideroblastic

anemiasanemiasMicrocytosisMicrocytosis

PolychromatophiliaPolychromatophilia

((reticulocytsisreticulocytsis), vitamin B12 (), vitamin B12 (cobalamincobalamin) or) or folatefolate

deficiency,deficiency, myelodysplasiamyelodysplasia, use of drugs that inhibit DNA synthesis, use of drugs that inhibit DNA synthesis

MacrocytosisMacrocytosis

ThalassemiaThalassemia,, hemoglobinshemoglobins

C, D, E, and S, liver disease,C, D, E, and S, liver disease, abetalipoproteinemiaabetalipoproteinemiaTarget cellsTarget cells

Autoimmune hemolytic anemia,Autoimmune hemolytic anemia, alloimmunealloimmune

hemolysishemolysis, hereditary, hereditary

spherocytosisspherocytosis, some cases of Heinz body hemolytic, some cases of Heinz body hemolytic anemiasanemiasMicrospherocytesMicrospherocytes

ThromboticThrombotic

thrombocytopenicthrombocytopenicpurpurapurpura, disseminated intravascular, disseminated intravascular

coagulation,coagulation,vasculitisvasculitis, malignant hypertension,, malignant hypertension, eclampsiaeclampsia, traumatic, traumatic

hemolysishemolysis

due to prosthetic heart valve or damaged vascular graft, thermadue to prosthetic heart valve or damaged vascular graft, thermall

injury (burns), postinjury (burns), post--splenectomysplenectomy

SchistocytesSchistocytes

andand

fragmentedfragmented RBCsRBCs

MyelofibrosisMyelofibrosis,, myelophthisismyelophthisis

(bone marrow infiltration by(bone marrow infiltration by neoplasticneoplastic

cells)cells)Teardrop cellsTeardrop cells

Sickle cells Hemoglobin SS, SC.Sickle cells Hemoglobin SS, SC.Sickle cellsSickle cells

HemolysisHemolysis, lead poisoning,, lead poisoning, thalassemiathalassemiaBasophilic stipplingBasophilic stippling

""GlucoseGlucose--66--phosphatephosphate dehydrogenasedehydrogenase

deficiency, other oxidantdeficiency, other oxidant--inducedinducedhemolysishemolysis, unstable, unstable hemoglobinshemoglobins

Bite" cells or "Bite" cells or "blister"cellsblister"cells


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Approach To Anemia(continue)Other Investigations are guided by the clinical impression after the

initial evaluation.

1-Iron Studies.

2-Measurment of vitamin B12 and Folate

serumlevels.

3-Bone Marrow Aspirate and Biopsy.4-Coomb,s Test.

5-Osmotic Fragility test.

6-Hemoglobin Electrophoresis.

7-RBC enzyme studies.

8-Chromosomal studies,Molecular

studies.9-Other studies.


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Normal Blood FilmNormal Blood Film

R i lR i l


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ReticulocytesReticulocytes


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Tear Drop CellsTear Drop Cells


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Basophilic StipplingBasophilic Stippling


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MacrocytesMacrocytes

andand HypersegmentedHypersegmented

NeutrophilNeutrophil


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HypochromiaHypochromia

andand MicrocytosisMicrocytosis


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Sickle RBCSickle RBC


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HypochromiaHypochromia

and Target Cellsand Target Cells

F d RBCF t d RBC


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Fragmented RBCFragmented RBC


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Blister RBCBlister RBC


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Aplastic

Bone Marrow Biopsy


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Megaloblastic

Bone Marrow

Iron Deficiency AnemiaIron Deficiency Anemia


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Iron Deficiency AnemiaIron Deficiency Anemia

Iron MetabolismIron Metabolism::IRON INTAKE (Dietary)

-

average adult diet = 10-20 mg Fe/day-

absorption = 5-10% (0.5-2 mg/day)-

Fe absorption increases with

increased erythropoiesis

e.g. pregnancy anemia Fe depletion

-

males have a positive Fe balance

-

menstruating females have a negative Fe balancePHYSIOLOGIC CAUSES OF INCREASED IRON REQUIREMENTS-

infancy-growth spurt 2x basal need-

puberty-growth spurt, menarche 3x basal need

-

pregnancy 4x basal need-

blood donation 4x basal need 500 mL

blood = 250 mg FeIRON ABSORPTION

-

occurs in duodenum mainly .

IRON TRANSPORT


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IRON TRANSPORT

Majority of non-heme

Fe in plasma is bound to a beta-globulin calledtransferrin

Transferrin

carries Fe from mucosal cell to RBC precursors in marrow.

carries Fe from storage pool in hepatocytes

and macrophages to RBC

precursors in marrow.IRON STORAGE

Fe is stored in two forms: ferritin

and hemosiderin.

Ferritin

ferric Fe complexed

to a protein called apoferritin.

hepatocytes

are the main site of ferritin

storage.

minute quantities are present in plasma in equilibrium with theintracellular ferritin.

Hemosiderin

aggregates or crystals of ferritin

with the apoferritin

partially removed

macrophage-monocyte system is the main source of hemosidirin.

IRON METABOLISM


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IRON METABOLISM

Causes of IDACauses of IDA


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Causes of IDACauses of IDA

PHYSIOLOGIC CAUSES

Increased need for iron in the body.

Infancy.

Adolescence, menstruation.

Pregnancy, lactation.

PATHOLOGIC CAUSES

In adult males and post-menopausal females, Fe deficiency is usuallyrelated to chronic blood loss mainly from GIT.

Dietary deficiencies (rarely the only etiology)

cows milk (infant diet)

poor dietary iron intake

(elderly)

Absorption imbalances

post-gastrectomy malabsorption

Hemorrhage

obvious causes -

menorrhagia occult -

peptic ulcer disease, aspirin, GI tract cancer,ankylostoma. Intravascular hemolysis;iron will be lost in the urine.

CLINICAL PRESENTATION Of IDA


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CLINICAL PRESENTATION Of IDA

Iron deficiency may cause fatigue before clinical anemiadevelops

Brittle hair

Dry skin

Dysphagia

(esophageal web, Plummer-Vinson ring)

Nail changes brittle

koilonychia

Glossitis

Angular stomatitis

Pica (appetite for bizarre substances e.g. ice, paint, clay)


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IRON INDICES


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IRON INDICES* Bone marrow biopsyis the gold standard test for iron stores.

Serum ferritin

Single most important blood test for iron stores.

Falsely elevated in inflammatory disease, liver disease(from necrotic hepatocytes), neoplasm and hyperthyroidism.

Serum iron

A measure Fe present in blood.

Virtually all serum iron is bound to transferrin.

Only a trace of serum Fe is free or complexed

in ferritin.

Total iron binding capacity (TIBC)

measure of total amount of transferrin

present in blood.

normally, one third of the TIBC is saturated with Fe, the

remainder is unsaturated

Transferrin Saturation

serum Fe divided by TIBC, expressed as a proportion

or a percentage.

Diagnosis of IDADiagnosis of IDA


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Diagnosis of IDADiagnosis of IDA

Laboratory Investigations

1-

Peripheral blood film

Hypochromic

microcytic

RBC.

Pencil forms.

Target cells (thin).

Platelet count may be elevated.

2-

Serum Iron Studies

low s.iron,high

TIBC,low

Fe saturation

S. ferritin

< 20 ug/l

is diagnostic of iron deficiency anemia,Iron

deficiencyanemia unlikely if ferritin

> 100 ug/l.

Increased plasma level of soluble transferrin

receptors.

3-

Hemoglobin Electrophoresisdecreased Hb

A2 percentage.

4-

Bone marrow study

(Needed in difficult cases)

Predominence

of intermediate and late erythroblasts.

Micronormoblastic

maturation of erythroid

precursors.

Fe stain (Prussian blue) shows decreased iron in macrophages.

Decreased sideroblasts.


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Tr tm nt of IDATreatment of IDA


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Treatment of IDATreatment of IDA

ANEMIA REFRACTORY TO ORAL IRONMedication Problem:

Poor preparation (e.g. expired).

Drug interactions.

Patient Problem:

Poor compliance.

Bleeding continues.

Malabsorption

(rare).

Physician Problem:

Misdiagnosis.


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Causes ofCauses of MegaloblasticMegaloblastic AnemiaAnemia


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Causes of Megaloblasticg

Anemia

I.I. Cobalamin(vitCobalamin(vit

B12) deficiencyB12) deficiency

A. Decreased ingestion: vegetarians.A. Decreased ingestion: vegetarians.B. Impaired absorption: small intestinal disease.B. Impaired absorption: small intestinal disease.

C.ImpairedC.Impaired

utilization.utilization.

II.II. FolateFolate

deficiencydeficiency

A. DecreasedA. Decreased ingestion:prolongedingestion:prolonged

parenteralparenteral

feeding,alcoholismfeeding,alcoholism..

B. ImpairedB. Impaired absorption:smallabsorption:small

intestinal disease.intestinal disease.

C. ImpairedC. Impaired utilization:drugutilization:drug

inducedinduced egeg; sulfa; sulfadrugs,methotrexate,phenytoindrugs,methotrexate,phenytoin

D. IncreasedD. Increased requirement:pregnancy,hemolysisrequirement:pregnancy,hemolysis..

E. IncreasedE. Increased loss:throughloss:through

urine.urine.

III. DrugsIII. Drugs metabolic inhibitorsmetabolic inhibitors

IV. MiscellaneousIV. Miscellaneous

A. Inborn errorsA. Inborn errors

B. Unexplained disordersB. Unexplained disorders

CobalamineCobalamine MetabolismMetabolism


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CobalamineCobalamine

MetabolismMetabolism

CobalamineCobalamine

is an animal product. Daily need=1microgramis an animal product. Daily need=1microgram

Under normal conditions of gastric acidity, dietaryUnder normal conditions of gastric acidity, dietarycobalamincobalamin

enters the duodenum bound to R protein.enters the duodenum bound to R protein.

AdditionalAdditional cobalamincobalamin

bound to R protein enters thebound to R protein enters theduodenum after secretion into bile by the liver (the onlyduodenum after secretion into bile by the liver (the onlysignificant route by whichsignificant route by which cobalamincobalamin

is lost from the body).is lost from the body).Pancreatic proteases partially degrade salivary andPancreatic proteases partially degrade salivary and biliarybiliaryRRproteinproteincobalamincobalamin

complexes in the jejunum;complexes in the jejunum; cobalamincobalamin isisbound to intrinsic factor only after this process occurs. Thebound to intrinsic factor only after this process occurs. Theintrinsic factorintrinsic factorcobalamincobalamin

complex remains intact until itcomplex remains intact until itreaches the distal end of the ileum, where it binds with highreaches the distal end of the ileum, where it binds with highaffinity to specific receptors located onaffinity to specific receptors located on ilealileal

mucosal cells.mucosal cells.CobalaminCobalamin

then enters these cells and reaches the portalthen enters these cells and reaches the portal

plasma, which contains threeplasma, which contains three cobalamincobalamin

binding proteinsbinding proteinsknown asknown as transcobalamintranscobalamin I, II, and III).I, II, and III).

Cobalamine Metabolism


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Cobalamine

Metabolism

FolateFolate MetabolismMetabolism


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FolateFolate

MetabolismMetabolism

FolateFolate

is widely distributed in plants and in products of animal origiis widely distributed in plants and in products of animal origin;n;green vegetables are particularly rich sources ofgreen vegetables are particularly rich sources of folatefolate

.Daily.Dailyneed=50microgram.need=50microgram.

FolatesFolates

in natural foods are conjugated to chains ofin natural foods are conjugated to chains of polyglutamicpolyglutamic

acid. Enzymes in the lumen of the small intestine convert theacid. Enzymes in the lumen of the small intestine convert thepolyglutamatepolyglutamate

forms offorms of folatefolate

to theto the monoglutamatemonoglutamate

andand diglutamatediglutamateforms, which are readily absorbed in the proximal portion of theforms, which are readily absorbed in the proximal portion of thejejunum. Most of thejejunum. Most of the folatefolate

in plasma is present as 5in plasma is present as 5--

methyltetrahydrofolate in themethyltetrahydrofolate in the monoglutamatemonoglutamate

form. The majority isform. The majority isloosely bound to albumin, from which it is readily taken up by tloosely bound to albumin, from which it is readily taken up by thehehighhigh--affinityaffinity folatefolate

receptors present on cells throughout the body.receptors present on cells throughout the body.

Once it enters the cell, 5Once it enters the cell, 5--methyltetrahydrofolate must be convertedmethyltetrahydrofolate must be convertedtoto tetrahydrofolatetetrahydrofolate

by theby the cobalamincobalamin--dependent enzymedependent enzyme methioninemethioninesynthasesynthase

before it can be converted to thebefore it can be converted to the polyglutamatepolyglutamate

form andform andtake part in the othertake part in the other folatefolate--dependent enzymatic reactions. Independent enzymatic reactions. In

addition to being secreted into bile and reabsorbed in the smalladdition to being secreted into bile and reabsorbed in the smallintestine,intestine, folatesfolates

are also degraded and excreted in the urineare also degraded and excreted in the urine


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FolateFolate

andand CobalamineCobalamine

metabolismmetabolism

Clinical Manifestations ofClinical Manifestations of MegaloblasticMegaloblastic AnemiaAnemia


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Clinical Manifestations ofClinical Manifestations of MegaloblasticMegaloblastic

AnemiaAnemia

1.1.

Symptoms of slowly progressiveSymptoms of slowly progressive anaemiaanaemia

2.2.

Jaundice(Jaundice(CobalamineCobalamine

deficiencydeficiency).).

3.3.

GlossitisGlossitis

4.4.

StomatitisStomatitis5.5.

Gastrointestinal symptomsGastrointestinal symptoms

6.6.

Orthostatic hypotensionOrthostatic hypotension7.7.

Weight lossWeight loss

8.8.

NeuropsychiatricNeuropsychiatric::inin CobalamineCobalaminedeficiencydeficiency

ParesthesiaParesthesia

, Abnormal gait , Memory loss., Abnormal gait , Memory loss.

Disorientation, Decreased or Increased reflexes,Disorientation, Decreased or Increased reflexes,

Romberg's sign.Romberg's sign.SpasticitySpasticity,, Babinski'sBabinski's sign, Psychosis, Slowsign, Psychosis, Slow MentationMentation..

Laboratory InvestigationsLaboratory Investigations


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Laboratory InvestigationsLaboratory Investigations11--

Complete Blood Count &Blood Film:Complete Blood Count &Blood Film:

MacrocytosisMacrocytosis

(increased(increased MCV),Neutropenia,ThrombocytopeniaMCV),Neutropenia,Thrombocytopenia,,NeutrophilNeutrophil

hypersegmentationhypersegmentation,, ReticulocytopaeniaReticulocytopaenia

22--

Bone Marrow Aspirate &Biopsy:Bone Marrow Aspirate &Biopsy:

HypercellularHypercellular,, MegaloblasticMegaloblastic

morphologymorphology

,Giant bands,Giant bands&&metamyelocytesmetamyelocytes..

33--

IndirectIndirect HyperbilirubinemiaHyperbilirubinemia, elevated, elevated s.LDHs.LDH..

44--

SerumSerum cobalamincobalamin: in: in cobalaminecobalamine

deficiencydeficiency(normal(normal, 200, 200900900

pg/pg/mLmL).).55--

SerumSerum folatefolate: in: in folatefolate

deficiency(normaldeficiency(normal, 2.5, 2.52020 ng/mLng/mL).).

66--

Schilling Test for diagnosing the cause ofSchilling Test for diagnosing the cause of CobalamineCobalaminemalabsorptionmalabsorption..

77--

Gastric biopsy forGastric biopsy for perniciouspernicious anemia(cobalamineanemia(cobalamine

deficiency)deficiency)and/or Small Intestinal Biopsy forand/or Small Intestinal Biopsy for malabsorptionmalabsorption

..

88--

AntiAnti--Intrinsic factorIntrinsic factorAbAb& Anti& Anti--Parietal cellParietal cellAbAb

inin PerniciousPernicious

anemia(Cobalamineanemia(Cobalamine

deficiency).deficiency).99-- Elevated serumElevated serum MethylmalonicMethylmalonic acid inacid in CobalamineCobalamine deficiencydeficiency..

PERNICIOUS ANEMIATh f b l i l b i i


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The most common cause of cobalamin

malabsorption ispernicious anemia, a disease of unknown origin in which the

fundamental defect is atrophy of the gastric (parietal cell)oxyntic

mucosa eventually leading to the absence of IF andHCl

secretion. Because cobalamin

is only absorbed by

binding to IF and uptake by ileal

IF-cobalamin

receptors, thenet consequence is severe cobalamin

malabsorption

leadingto cobalamin

deficiency.

There is a significant association of pernicious anemia withother autoimmune diseases. There is a positive family historyfor about 30% of patients, among whom the risk of familialpernicious anemia is 20 times as high as in the general

populationThe

histologic

appearance of the gastric mucosa(infiltration with plasma cells and lymphocytes) is alsostrongly reminiscent of autoimmune-type lesions. There is

also a high incidence of anti-parietal cell IgG

antibodies inthe serum of 90% of patients with pernicious anemia.

Treatment ofTreatment of MegaloblasticMegaloblastic AnemiaAnemia


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Treatment ofTreatment of MegaloblasticMegaloblastic

AnemiaAnemia

CobalamineCobalamineDeficiency:Deficiency:HydroxycobalamineHydroxycobalamine

1 mg1 mg i.mi.m. daily for 10 days. daily for 10 days

,then once every one month for,then once every one month for life.Ironlife.Iron

is addedis addedfor slow response.for slow response. HypokalemiaHypokalemia

may developmay develop

during therapy.during therapy. ReticulocytosisReticulocytosis

at day 7 will indicateat day 7 will indicate

response.response.

Blood is given forBlood is given for severlyseverly

symptomatic patients.symptomatic patients.

FolateFolateDeficiency:Deficiency:Oral Folic acid 5 mg/day for 3 weeks then weeklyOral Folic acid 5 mg/day for 3 weeks then weekly

as maintenance.as maintenance.

Anemia of Chronic DiseaseAnemia of Chronic Disease


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Anemia of Chronic DiseaseEtiology

Infections, cancer, endocrine disorders (e.g. thyroid).

Inflammatory and rheumatologic disease.

Renal disease.Pathophysiology

A mild hemolytic component is often present, red blood

cell survival is moderately decreased.

Erythropoietin levels are normal or slightly elevated but

are inappropriately low for the degree of anemia,erythropoietin level is low in renal failure

Iron cannot be removed from its storage pool in

hepatocytes

and RES cells.


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AplasticAplasticAnemiaAnemia


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pp

Etiology

Radiation

Drugs

anticipated (chemotherapy)

idiosyncratic (chloramphenicol, phenylbutazone)

Chemicals

benzene and other organic solvents

DDT and insecticides

Post viral e.g. hepatitis B, parvovirus,HIV.

Idiopathic

often immune (cell mediated)

Paroxysmal nocturnal hemoglobinuria

Marrow replacement

Congenital: Fanconi

anemia,associated

with dysmorphic

features.

Abnormal Thumbs in Fanconi Anemia


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Abnormal Thumbs in Fanconi

Anemia

Clinical Presentation of Aplastic Anemia


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Clinical Presentation of Aplastic

Anemia

Occurs at any age

Slightly more common in males.

Can present acutely or insidiously.

Features of anemia or neutropenia

or

thrombocytopenia (any combination).1.

Thrombocytopenia as bruising, bleeding

gums, epistaxis.

2.

Anemia as SOB, pallor and fatigue.

3.

Presentation of neutropenia

ranges from

infection in the mouth to septicemia.

AplasticAplastic AnemiaAnemia


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AplasticAplastic

AnemiaAnemiaDiagnosis

1-

CBC: Pancytopenia

normochromic

normocytic

anemia.

neutrophil

count < 1.5 x 109/L.

platelet count < 20 x 109/L.

corrected reticulocyte

count < 1%.2-

Bone marrow aspirate and biopsy

aplasia

or hypoplasia

of marrow cells with fat replacement.

Management

Removal of offending agents.

Supportive care (red cell and platelet transfusions, antibiotics).

Antithymocyte

globulin (50-60% of patients respond) for patients who are >45

years of age and those who have no donor for bone marrow transplant

Cyclosporin

A,mainly

useful for mild cases.

Allogeneic

bone marrow transplantation for patients


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MYELODYSPLASTIC SYNDROMES (MDS)PathophysiologyPathophysiology

A group of clonal

bone marrow stem cell disorderscharacterized by one or more cytopenias

with anemia

present.

Ineffective hematopoiesis

despite presence of adequate

numbers of progenitor cells (bone marrow is usually

hyper-cellular).

Dysplastic changes affect all the hematopoietic cell

lines due to abnormal maturation and differentiation

which include abnormal size , nuclear shape andcytoplasmic

granules

The blood elements are dysfunctional.There is increased liability for transformation to AML.


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Dysplastic nuclear features in circulating cells. Composite image taken from several cases of

myelodysplastic

syndrome showing dysplastic nuclear features seen in circulatinggranulocytes and nucleated RBCs. The right lower figure shows numerous Pappenheimer

bodies.

MDSMDS


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MDSTypes

Refractory anemia (RA).

Refractory anemia with ring sideroblasts

(RARS).

Refractory anemia with excess blasts

(RAEB).Refractory anemia with excess blasts in

transformation (RAEB-T).Chronic myelomonocytic

leukemia

(CMML).

MDSMDS


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MDSClinical Presentation

Related to bone marrow failure, most common inelderly, usually > 70 and post-chemotherapy or radiation

Usually insidious in onset: fatigue, weakness, pallor,infections, bruising and rarely weight loss, andhepatosplenomegaly

Diagnosis

1-

Anemia

thrombocytopenia

neutropeniaRBC: variable morphology with decreased reticulocytecount,

WBC: decrease in granulocytes and abnormal function,

Platelet: either too large or too small andthrombocytopenia

2-

Bone marrow : dysmyelopoiesis

in bone marrow

precursors3- Chromosomal Abnormalities:5,7,8 ,others

MDSMDS


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Management

1-

Symptomatic (transfusion, antibiotics)

2-

Growth factors: Erythropoietin,G-CSF.3-

Cytotoxics

for RAEB & RAEB-

T&CMML4-

Bone marrow transplant for young

patients with advanced disease.5-

Immune modulating and differentiating

agents .

Hemolytic anemiasD fi i i A i h l f h i f RBC lif RBC


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Definition:Anemias

that result from shortening of RBC life span,RBC

destruction could be extravascular

or intravascular

EtiologyEtiology

Congenital

1-

Membrane abnormalities

Hereditary spherocytosis

Hereditary elliptocytosis

2-Haemoglobinopathies

Lack of haemoglobin

chainsynthesis Thalassaemias

Amino acid substitution onthe haemoglobin

chain

Haemoglobin

S. C, D3-

Red cell enzyme detects

Glucose-B-phosphatedehydrogenase

deficiency

Acquired1-

Immune

Isoimmune

Autoimmune Warm antibodyCold antibody

Alloimmune

2-

Non-immune

Mechanical-

Artificial cardiac valves

-

Burns

-

Microangiopattlic

-

March haemoglobinuria Infections

Clostridium perfringens,malaria

Drugs, chemicals3-

Paroxysmal nocturnalhaemoglobinuria (PNH).

Approach To Hemolytic anemiaApproach To Hemolytic anemia


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pp ypp yA- Prove The Presence of Hemolysis(Evidence of hemolysis):

Clinical Features: anemia +jaundice.

Laboratory Tests

1-

Low Hb, Increased reticulocytecount and percentage.

2-

Indirect

hyperbilirubinemia,raised

s.LDH,increased

urinary

urobilinogen.3-

Low serum haptoglobin.

4-

Hemosiderinurea,hemoglobinurea

in cases of intravascular

hemolysis.B-Find The Cause OfHemolysis:

1-

Blood Film Morphology: Target Cells,Sickle

Cells,Heinz

Bodies,

Blister Cells, Fragmented RBC, Spherocytes.2-

Hemoglobin Electrophoresis: for Hemoglobinopathies.

3-

Osmotic Fragility test for Spherocytosis

4-

Enzyme assay for Enzymopathies.

5-

Coomb,s

test for immune hemolysis.

6- Ham,s test for PNH.

HereditaryHereditary spherocytosisspherocytosis


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yy p yp yThis is anThis is an autosornalautosornal

dominantdominant

disorder in whichdisorder in which

the principal abnormality appears to be a deficiency ofthe principal abnormality appears to be a deficiency ofspectrinspectrin,a,a

red cell membrane protein. Approximatelyred cell membrane protein. Approximately

25% of patients have no family history. The erythrocyte25% of patients have no family history. The erythrocyteenvelope is abnormally permeable and the sodiumenvelope is abnormally permeable and the sodium

pumps are overworked. The exact nature of the redpumps are overworked. The exact nature of the red

blood cell defect may vary from family to family. Theblood cell defect may vary from family to family. Theerythrocytes lose their biconcave shape, becomeerythrocytes lose their biconcave shape, become

sphericalspherical

and are more susceptible to osmoticand are more susceptible to osmotic lysislysis..

TheseThese spherocytesspherocytes

are destroyed almost exclusively byare destroyed almost exclusively by

thethe spleenspleen. The severity of the disorder is very variable. The severity of the disorder is very variable

even within an affected family.even within an affected family. HaemolysisHaemolysis

is mainlyis mainlyextravascularextravascular..

Diagnosis &TreatmentDiagnosis &Treatment


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ggClinical Features:

The severity of anemia

is variable from asymptomatic totransfusion dependent anemia.Jaundice

is also variable,as

well assplenomegaly.

Complications include

1-

Crises (hemolytic, megaloblastic, and aplastic). 2-

Pigment Gall stones.

Lab Tests:

Evidence of Hemolysis: Anemia, Reticulocytosis, raised S.LDH

Spherocytes

on blood film.

+ve

Osmotic Fragility Test.

-ve

Coombs Test.

Treatment :

1-Blood Transfusion.

2-Folic acid.

3-Splenectomy for moderate to severe cases.

OSMOTIC FRAGILITY TEST


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OSMOTIC FRAGILITY TEST

Glucose 6 PhosphateGlucose 6 Phosphate DehydrogenaseDehydrogenase DeficiencyDeficiency


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G6PD Enzyme is the first one in thehexosmonophosphate

shunt, the function of thisshunt is to service the enzymes glutathione

reductase

and glutathione peroxidase, which protectthe red cells against damage due to oxidation.

The deficiency is inherited as an X-linked disorderwith a high frequency among Black Africans whopossess an electrophoretic

enzyme polymorphism

with A and B type enzymes. The enzyme is A type(A-)

in deficient Black Africans. In Caucasians onlythe normal B type enzyme is found and the deficient

type is also B (B-).


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G6PD deficiencyG6PD deficiency


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yy

Lab Tests:1-

Anemia, reticulocytosis,

indirect hyperbilirubinemia

2-

Blister RBC on blood film,and Heinz bodies.

3-

Hemoglobinurea

and later

hemosideriurea.4-

Enzyme assay is useful

after recovery.

Treatment:1-

Avoid fava

beans and oxidant drugs.2-

For the hemolytic episode: stop the offending factor,

blood transfusion, folic acid.

HAEMOGLOBINOPATHIESHAEMOGLOBINOPATHIEST


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The haemoglobinopathies

can be classified into

two subgroups:1-

Where there is an alteration in the amino acid

structure of the polypeptide chains of the glohinfraction of haemoglohin, commonly called the

abnormal haemoglohins: the best-known

example is haemoglobin

S found in sickle-cellanaemia.

2-Where the amino acid sequence is normal butpolypeptide chain production is impaired or

absent for a variety of reasons: these are the

Thalassemias.

Hemoglobin Structure and Production


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Fetal hemoglobin, HbF

(22) switches toadult forms HbA

(22) and HbA2 (22) at

3-6 months of life.

HbA

constitutes 97% of adult hemoglobin.

HbA2 constitutes 3% of adult hemoglobin. 4

genes are located on chromosome 16.

2

genes are located on chromosome 11.There is the possibility of mixed defects

e.g. -thalassemia

minor and sickle cell (HbS)trait.

Hemoglobin Structure


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g

THALASSEMIASHETEROZYGOU THALASSEMIA


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HETEROZYGOU

THALASSEMIA

: -ThalassemiaMinor

Common condition in Mediterranean Basin ,Africa,AsiaClinical Presentation

Mild or no anemia.

Spleen sometimes is palpable.

May be masked by Fe deficiency and sometimes confused with irondeficiency anemia.

Diagnosis

1-

Hb

9-12 g/dL, MCV < 702-

Microcytosis

+/ hypochromia,target

cells present,basophilicstippling usually present.

3-

Hb

electrophoresis: Hb

A2 increased to 3.5-5% (normal 1.5 -

3.5%),50% of individuals have slight increase in HbF.

Management

Add folic acid.

Patient and family should receive genetic counseling.


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PATHOPHYSIOLOGY OF B-THALASSEMIA MAJOR


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-Thalassemia Major


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Diagnosis

1-

Hemoglobin 4-6 g/dL.

2-

Peripheral blood: hypochromic

microcytosic,

increased reticulocytes, basophilic stippling,target cells.

-

Postsplenectomy

blood film shows Howell Jollybodies, Nuleated

RBC, and thrombocytosis.

3-

Hb

electrophoresis

Hb

A: 0-10% ( normal > 95%)

Hb

F: 90-100%

4-DNA analysis.

-Thalassemia Major


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Management

1-

Blood transfusions to ensure growth and decreaseskeletal deformities ,try to keep Hb

> 10 gm/dL, addfolic acid.

2-

Fe chelators

to prevent iron overload likedesferrioxamine, deferiprone.

3-Ensure good nutrition and try to minimize thefrequency of infectious episodes by

vaccination.Infections

should be treated adequately.

3-

Allogeneic

Bone marrow transplant (if suitabledonor).

4-

Splenectomy

for mechanical problems and

hypersplenism.5- Genetic counseling for prevention.

ALPHA THALASSEMIASPathophysiology


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p y gy

Autosomal

recessive

Deficit of alpha chains

4 grades of severity depending on the number of defective alphagenes

1 -

silent: / -

2 -

trait: /--

or -/ -

3 -

Hb

H Disease (presents in adults) : -/--

4 -

Hb

Barts (hydrops

fetalis): --/--

Hb

Barts made of 4 gamma chains; not compatible with life

Hb

H made of 4 beta chains, is unstable, and leads to inclusionbodies

Diagnosis1-

Peripheral blood film: microcytes, hypochromia, occasional

target cells, screen for Hb

H inclusion bodies.

2-

Hb

electrophoresis not diagnostic.

3-

DNA analysis using alpha gene probe.Management: same as beta thalassemia.

PATHOPHYSIOLOGY OF ALPHA THALASSEMIAS


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HEMOGLOBIN H INCLUSION BODIES


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Sickle Cell anemiaSickle Cell anemia


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Autosomal

recessive

Amino acid substitution of valine

for glutamate inposition 6 of beta

globin

chain.

*It has a wide geographical distribution.

Sickle Cell anemiaSickle Cell anemia


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Mechanisms of Sickling

At low PO2, deoxy

Hb

S polymerizes, leading to rigidcrystal-like rods that distort membrane = SICKLES

The PO2 level at which sickling

occurs is related to the

% of Hb

S present-

If the patient is heterozygous (Hb

AS), the sicklingphenomenon occurs at a PO2 of 40 mmHg

-

If the patient is homozygous (Hb

SS), sickling

occursat 80 mmHg

Sickling

is also aggravated by

Acidosis.

Increased CO2.

Increased 2,3-DPG.

Increased temperature and osmolality.

Clinical Consequences Of SCAClinical Consequences Of SCA


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Heterozygous SCA: Hb S TraitCli i l t ti


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Clinical presentation:

the patient will appear normal except at times ofextreme hypoxia and infection, elderly patients may

suffer from loss of renal concentration ability.

Diagnosis:

1-

Hb

level is normal

2-

Peripheral blood: normal except for a few target cells3-

Hb

electrophoresis (confirmatory test): Hb

A fraction

of 65% ; Hb

S fraction of 35%

Treatment:1-

Avoid hypoxia during flying and surgery.

2-

Folic acid for pregnant.3- Genetic counseling.

HEMOGLOBIN ELECTROPHORESIS IN SCA


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Homozygous SCA: Hb

SS Disease


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Diagnosis

1-

Peripheral blood: sickled

cells,target

cells,

reticulocytosis.2-

Indirect hyperbilirubinemia, raised s.LDH

3-

Screening test: sickle cell preparation searching

for sickling

phenomenon.4-

Hb

electrophoresis (confirmatory test): Hb

Sfraction > 80%,the rest is Hb

F.

Homozygous SCA: Hb SS DiseaseManagement


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g

1-

Prevention Of Sickling

Attacks:

Avoid conditions that favor sickling

(hypoxia, acidosis,dehydration, fever).

Vaccination in childhood e.g. pneumococcus,

meningococcus.

Good hygiene and nutrition.

2-

Genetic counseling.

3-

Blood transfusion to keep Hb>8 g/dl + Iron chelation forfrequent transfusions.

4-

Folic acid to avoid folate

deficiency.

5-

Hydroxyurea

to enhance production of Hb

F, presence of Hb

F in the SS cells decreases polymerization and precipitationof Hb

S.

Note: Hydroxyurea

is cytotoxic

and may cause bone marrowsuppression it is indicated in severe cases.

6-

Experimental anti-sickling

agents.

7- Allogeneic Bone marrow transplant for selected patients.

Homozygous SCA: Hb SS Disease


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Treatment of Vaso-Occlusive Crisis

Oxygen.

Good Hydration (reduces viscosity).

Antimicrobials.

Correct acidosis if severe.

Analgesics/narcotics (give enough to relieve

pain).

Exchange transfusion for CNS crisis.

AUTOIMMUNE HEMOLYTIC ANEMIATypes:Types:


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ypyp

11--

Warm Antibody type :usuallyWarm Antibody type :usually IgGIgG..

22--

Cold Antibody type:Cold Antibody type: usuallyusually IgMIgM..

Warm Antibody type)Warm Antibody type)(AUTOIMMUNE HEMOLYTIC ANEMIA

Pathophysiology: RBC are coated with IgG

or complement (C3d)or both leading to extravascular

hemolysis

in RES (mainlyspleen).

Classification:

1-

idiopathic2-

secondary to

Lymphoproliferative

disorders (CLL, Hodgkins disease,

Non -

Hodgkins lymphoma)

Autoimmune (SLE)

3-

Drug induced (penicillin, quinine/quinidine, alpha methyl dopa)

Clinical Features:

Usually insidious :anemia, jaundice and splenomegaly.


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Mechanism of extravascular

hemolysis

in autoimmune hemolytic anemia. (A) Macrophage

encounters an lgG-coated erythrocyte and binds to it via its Fc

receptors. Thus entrapped,

the RBC loses bits of its membrane as a result of digestion by the macrophage. The discoid

erythrocyte transforms into a sphere. (B) RBC lightly coated with lgG

(and therefore

incapable of activating the complement cascade) is preferentially removed in the sluggishcirculation of the spleen. (C) RBC with a heavy coat of lgG; thus, C3b (black circles) can be

removed both by the spleen and the liver.

AUTOIMMUNE HEMOLYTIC ANEMIA(Warm Antibody type)Warm Antibody type)


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(Warm Antibody type)Warm Antibody type)

Diagnosis1-

Spherocytes

in blood film, reticulocytosis.

2-

Indirect hyperbilirubinemia, raised s.LDH.

3-

Positive direct antiglobulin

test (direct Coombs) best detected at37C (hence warm-reacting antibodies)

4-

Exclude delayed transfusion reaction.

Management

Treat underlying cause

Corticosteroids: prednisolone

1mg/Kg until response then taperover 2-3 months.

Splenectomy

for relapsed and corticosteroid resistant cases .

Immunosuppressives

like azathioprine

for relapses aftersplenectomy

Blood transfusion is used with caution. Add folic acid.

Autoimmune Hemolytic Anemia with Cold-Reacting Antibodies

Pathophysiology


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Pathophysiology

Either monoclonal or polyclonal IgM

Antibodies attach to RBC

surface antigens in peripheral circulation where T < 37C.Antibodies will detach from the surface antigen if T > thermal

amplitude

Thermal amplitude is the temperature at which IgM

is attachedto RBC surface

Associated with intravascular hemolysis

Classification Idiopathic

Secondary to

Lymphoproliferative

disorders (CLL, Hodgkins disease,

non-Hodgkins lymphoma)

Infections (Mycoplasma

pneumoniae, EBV).

Clinical Features:

Anemia, acrocyanosis, joint pain, vasculitic

rash, Raynaudphenomena, and rarely splenomegaly.

COLD AGGLUTININ


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Autoimmune Hemolytic Anemia with Cold-ReactingAntibodies (IgM)


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Diagnosis

1-

Anemia, mild reticulocytosis, RBC agglutination in

blood film .

2-

Positive cold agglutinin test best at 4C.3-

Positive direct Coombs

for complement at any

temperature.

Management

Treat underlying cause

Warm the patient above the thermal amplitude of theantibody

Plasmapheresis. Immunosuppressives like chlorambucil.

Non ImmuneNon Immune HemolysisHemolysis11 I f tiInf ti n


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11--

Infections:Infections:

Bacterial, Malaria,Bacterial, Malaria, BabesiaBabesia..

22--

Mechanical:Mechanical:

MicroangiopathicMicroangiopathic

HemolysisHemolysis

(MAHA): TTP, HUS,(MAHA): TTP, HUS,

DIC.DIC.

MarchMarch HemoglobinureaHemoglobinurea..

Mechanical Cardiac Valves.Mechanical Cardiac Valves.

33--

Snake bite.Snake bite.

44-- Burns.Burns.

Drug InducedDrug Induced HemolysisHemolysis


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11--

HaptenHapten

Mechanism: high dose PenicillinMechanism: high dose Penicillin

22--

Complement Fixation :Complement Fixation : quinidinequinidine

,, phenacetinphenacetin..

33--

Autoantibody production: LAutoantibody production: L--dopa, methyldopa.dopa, methyldopa.

44--

Nonspecific:Nonspecific: cephalothincephalothin..

55--

Metabolic: sulfa drugs.Metabolic: sulfa drugs.

HypersplenismHypersplenismIt is a state of sequestration of one or more of


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It is a state of sequestration of one or more of

blood elements in an enlarged spleen.Causes

1-

Portal hypertension

2-

Myeloproliferative

disorders.

3-

Thalassemia

major.

4-

Others.Diagnosis1-

Reduction of one or more of blood elements.

2-

Normal cellularity

of bone marrow.

Treatment

hematology lectures 2011

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