CR Hematology
CR Hematology
RBCs DisordersAnemias
&Others
WBCs DisordersBenign & Malignant
Hemostatic Disorders
Hematological Disorders
Introduction
• Blood consists of 55% plasma and 45% formed elements.
• Formed elements include erythrocytes, leukocytes, and thrombocytes.
Erythrocytes• Normal range 4.0-5.0
million per mm3 in adults.
• Biconcave shape.• Diameter 7 microns.• Cells for transport
of O2 and CO2.
• Life span 120 days.
Leukocytes
• Normal range 4 - 11 thousand per mm3
in adults.• Five types.• Size 8-20 microns.• Involved in fighting
infection, combating allergic reactions, and immune responses.
Thrombocytes
• Smallest cells in the blood.
• Normal range 150,000-400,000.
• Active role in coagulation and hemostasis.
RBC Disorders
Anemia• Defined by measurement of hemoglobin
concentration.• Manifestations (symptoms) are related to
duration and severity of anemia– Body has physiologic responses to chronic
anemia such that many patients are asymptomatic until hg < 8 g/dl .
– Fatigue, pallor, dyspnea, dizziness and dyspnea on exertion
Signs
• Pallor of mucous membranes (conjunctiva, tongue, palm of the hands).
• Nails are delicate and break easily.• Hair is thin.• Rough skin.
Classifications of Anemias
Microcytic, HypochromicMicrocytosis – small cells (MCV <80)
– Iron deficiency– Sideroblastic– Anemia of chronic disease– Lead poisoning– Thalassemia trait
Microcytic, Hypochromic
• Many RBCs smaller than
nucleus of normal
lymphocytes, increased central pallor.
Classifications of AnemiasNormochromic
– Hereditary Spherocytosis– PNH– G6PD deficiency– Aplastic anemia– Acute blood loss
Classifications of Anemias
Macrocytic– Vitamin B12 deficiency– Folate deficiency– Liver disease– Drugs– MPD
Macrocytic RBCs
• Most RBCs larger than nucleus of normal
lymphocytes.
• increased MCV.
Macrocytic Anemia
Macrocytosis – large cells (MCV >100)
Check vitamin B12, RBC folate (why?), fasting homocysteine, and methylmalonic acid (MMA)
*HC and MMA are elevated in subclinical B12 and folate deficiency
IRON DEFICIENCY ANAEMIA.
Iron deficiency is the most common cause of anemia in every common country of the world, and it is the most important cause of microcytic hypochromic anaemia.
Nutritional and metabolic aspects of the iron:
Iron in the body is about 2.5-3 g. Iron in the Haemoglobin of the RBC
represents a greatest percent of body constitutes.
Iron presents in the body in two forms:
- Ferrittin. - Haemosiderin.
Causes of iron deficiency anaemia:
1. Chronic blood loss, especially gastrointestinal tract.
2. Increased demands, during pregnancy, infancy, growth, lactation and menstruated women.
3. Malabsorption especially in the cases of gastroectomy and peptic ulcer.
4. Poor diet.
Clinical features:1. When IDA is developing, the RE stores
(hemosiderin and ferritin) become completely depleted before anemia occurs.
2. At an early stage, no clinical abnormalities.
3. Later, patient may develops general symptoms and signs of anemia.
4. Spoon or ridged nails in severe case of IDA.
5. Dysphagia.
Laboratory findings:•Red cell indices:
Low Hb conc.MCV, MCH, MCHC*
•Blood film:Hypochromic microcytic Picture.Occasional Target cells.Pencil shaped poikilocytes.Normal reticulocyte count.
•Bone marrow iron:Normal to hypercellular.RBC precursors are increased in number.Iron stain negative.
•Chemical testing on serum:Serum iron Decreased Transferrin/TIBC Normal to HighSerum ferritin Decreased (Very low)
DD. Of microcytic anemia
Sideroblastic anemias
Characterized by
Increase in total body iron
Presence of ringed sideroblasts in bone marrow
Hypochromic anemia.
Classification
• Hereditary form• Acquired form (more common)• Idiopathic – Refractory anemia with ringed
sideroblasts(RARS)• secondery
Pathophysiology
• Disturbances of enzymes regulating heme synthesis• Ringed sideroblasts form when non-
ferritin iron accumulated in the mitochondria that circle the normoblast nucleus
Hereditary Sideroblastic Anemia
• Most common form is sex-linked and due to an abnormal aminolevulinate
synthetase enzyme (ALAS)• Decreased heme synthesis due to block in iron utilization perceived by body as
increased need for iron associated with increased iron absorption results in iron overload
Acquired Sideroblastic Anemia
Idiopathic RARS– acquired stem cell disorder Secondary• Lead poisoning (plumbism) Inhibits cellular enzymes involved in heme
synthesis• Malignancy
Laboratory findings in SA –Peripheral Blood
• Moderate to severe anemia• Target cells• Basophilic stippling • ↑Fe, N to ↓TIBC, ↑% saturation, ↑ ferritin
• Bone marrow: -Erythroid hyperplasia -Ringed sideroblasts in more than 15% of
normoblasts.**Lower number of ringed sideroblast in variety of
hematological disorders.
Macrocytic anemia
Macrocytic anemia
• Other causes include:– Drug toxicity– Hypothyroidism– Liver disease– Myelodysplasia– MPO
Megaloblastic macrocytosis
• The smear in a patient with macrocytic anemia is helpful in identification of megaloblastic changes – macrocytes and hypersegmented neutrophils (>5 lobes)
• DD: B12 deficiency, folate deficiency, drugs that cause abn.DNA synthesis or folate metabolism, liver disease and myelodysplastic syndromes
• Non-megaloblastic macrocytosis, on smear patients may have large target cells and acanthocytes.
Folate deficiency Found in: Fruits (e.g. citrus, melon, bananas),
leafy green vegetables. Causes include:
Malabsorption MedicationsMalignancy HemodialysisDiseases/conditions associated with rapid cell
turnover such as pregnancy, infancy,….
Vitamin B12 deficiency Found in : (meat, fish) The body stores large amounts of B12 therefore
decreased dietary intake rarely lead to deficiency Medications to decrease stomach acid can also
contribute to B12 deficiency (antacids) Vegetarians can also contribute to B12 deficiency In addition to causing anemia, B12 deficiency can lead
to a metabolic peripheral=neuropathy and gastrointestinal disorders.
Diagnosis
1. Blood cell count:
• macrocytic anemia ( MCV>100fl )• thrombocytopenia• leucopenia (granulocytopenia)• low reticulocyte count 2. Blood smear: • macrocytosis , anisocytosis.• hypersegmentation of granulocytes
Diagnosis
3. Laboratory features hyperbilirubinemia elevation of lactate dehrogenase (LDH) serum iron concentration- normal or increased 4. Bone marrow smear hypercellular erythroid cell changes (megaloblasts, an abnormally large
cell with nuclear- cytoplasmic asynchrony) myeloid cell changes (hypertsegmentation) megakaryocytes are decreased and show abnormal
morphology
Hemolytic AnemiaNormocytic
Normochromic
Hemolytic Anemia•Congenital
–Membrane defects•Hereditary spherocytosis•Hereditary elliptocytosis
–Enzyme defects•G6PD deficiency, PKD.…,
Hemolytic Anemia
• Acquired– Classified according to site of RBC destruction and/or whether
mediated by immune system:• Intravascular• Extravascular• Immune• Non-immune
– Causes: –• Transfusion of incompatible blood• Autoimmune
– Warm (IgG-mediated) ; most common– Cold (IgM-mediated)
• Prosthetic valves• TTP/HUS• DIC• Cancer• Drugs
Haematological findings in HS
• Anaemia is usual.[Increased mean corpuscular hemoglobin concentration (MCHC)]
• Reticulocytosis 5-20%• Microspherocytes are seen in the blood film.
(densely staining with smaller diameters than normal red cells).
Other investigations
• The classic finding is that the osmotic fragility is increased.
• Autohaemolysis is increased and corrected by glucose.
• Direct antiglobulin test is normal
G6PD deficiency
• G6PD functions to reduce nicotinamide adenine dinucleotide phosphate (NADP) while oxidizing glucose-6-phosphate.
• NADPH is needed for the production of reduced glutathione (GSH) which is important to defend the red cells against oxidant stress.
Clinical features
• G6PD deficiency is usually asymptomatic.• Neonatal jaundice.• Acute haemolytic anaemia in response to
oxidant stress: drugs, fava beans or infections.
Laboratory diagnosis
• Between crises blood count is normal.• The enzyme deficiency is detected by
– One of a number of screening tests or– By direct enzyme assay on red cells.
• During the crisis, the blood film may show contracted and fragmented cells, bite, blister cells, ………
• Enzyme assay may give a false normal level in the phase of acute haemolysis.
• The blood film shows irregularly contracted cells [deep red arrows]
and sometimes hemighosts [deep blue arrow] in which all the hemoglobin appears to have retracted to one side of the erythrocyte
Polycythemia / Erythrocytosis
• Abnormal elevation of hemoglobin– Rule out “relative” polcythemia caused by contraction of plasma volume,
e.g. dehydration– Primary
• Polycythemia Vera– RBC production independent of EPO
» EPO level is low / positive JAK-2 is diagnostic– Uncommon– May be associated with leukocytosis, thrombocytosis, splenomegaly– Hyperviscosity
» Headache, vertigo, visual changes, mental confusion– Risk of transformation into acute leukemia– Treatment??
– Secondary• RBC production in response to increased EPO production
– EPO level is usually high• Very common• Usual etiology is chronic hypoxia (COPD)**……………. (250-500 ml) to maintain hct 45-50% and treat underlying problem
Reticulocytes• Immature RBCs.• Contain residual
ribosomal RNA.• Reticulum stains
blue using a supravital stain (new methylene blue).
• Counted and expressed as % of total red cells.
Reticulocyte Count
Retic % = # retics per 100 RBCs
Corrected retic= % retics x pt. HCT
45
Haemoglobinopathies
• A group of inherited disorders characterized by structural variations of the Hb molecule. They are Disorders of globin synthesis rather than heme synthesis.
• These may result from : 1. Synthesis of abnormal Hb2. Reduced rate of synthesis of NORMAL α or β
globin chains• Genetic defects of Hb are the most common
genetic disorders worldwide.
What are hemoglobinopathies?
SICKLE CELL ANAEMIA
Sickle cell disease is a group of haemoglobin disorders, in which there is inherence globin abnormality, caused by substitution of valine for glutamic acid in position 6 in the ß chain.
• Hb S is insoluble and forms crystals when exposed to low oxygen tension.
• Deoxygenated Hb polymerizes into long fibers which may block different areas of the microcirculation or large vessels causing infarcts of various organs.
Clinical features:- Chronic haemolysis, leads to jaundice and anemia.- Vaso-occlusion of blood vessels leads to pain.- Infarction and infections.
1. Low Hb.2. Peripheral blood film shows, sickle cells,
target cells and howell-Jolly body appears.3. Positive Sickling test (screening test).4. Hb electrophoresis (confirmatory test) :
-Hb SS : 80 – 100% - no Hb A - Hb F : 5 – 15%
Howell-Jolly bodies
• These are basophilic nuclear remnants (clusters of DNA) in circulating erythrocytes.
• They are usually observed in hemolytic anemia, following splenectomy, and in cases of splenic atrophy.
The Sickling Test
• This is a wet preparation.• 5 drops of reagent (Sodium dithionite), are added
to 1 drop of anticoagulated blood on a slide. Cover glass is put on and sealed with petrollium jelly/parraffin wax mixture.
• The reagent is a reducing agent.• In Hb SS, sickling occur immediately, while it may
take 1 hour in Hb S trait.
Hb S solubility Test
• This is done after the Hb electrophoresis to differentiate between some hemoglobins that have the same electrophoretic mobility. (Differentiate Hb D & Hb G from Hb S)
• Only Hb S precipitate in the reduced state when placed in a high molarity phosphate buffer (as it removes oxyegen from test environment).
• 0.05 ml of blood is added to 1 ml of the buffer and mixed in a test tube. Positive results : presence of Hb S : cloudy solution . Negative results : other Hbs : clear solution .
This is a benign condition, where there is no anaemia and normal appearance of RBC on the BF. Haematuria is the most common symptom. Care must be taken with anesthesia, pregnancy and at high altitude.
Sicle cell trait
THALASSAEMIA
*There are two alpha genes on each of two chromosome 16 (four genes in the diploid state)
*Only 2 beta globin genes, one on each chromosome 11
**Excess alpha chains are unstable -precipitates in the cell which bind to cell membrane, causing membrane damage
**Excess b chains *High oxygen affinity – poor oxygen transporter
*unstable
Thalassaemias are a heterogeneous group of genetic disorders, which results from a reduced rate of œ (alpha) and ß (beta) chain synthesis.
• In alpha thalassaemia, there is no or little alpha-chain syntheses.
• In beta thalassaemia, there is no or little beta-chain syntheses.
ALPHA THALASSEMIA
1- Major alpha- thalassaemia or Hydrops fetalis or Hemoglobin Barts : four genes deletion, leads to complete suppression in the synthesis of alpha-chain. Alpha chain is important in formation of hemoglobin F in neonate, so in this case the formation of this haemoglobin which is important for fetal life will fail, leading to death in uterus.
2- Three genes deletion: leads to moderate to sever microcytic hypochromic anaemia, with splenomegaly. This is known as Hb H disease.
3- Two genes deletion: alpha-thalassaemia trait or minor, associated with mild anaemia.
4-One gene deletion: silent thalassemia usually asymptomatic.
Alpha-Thalassemia minor
*Two alpha genes either on same or opposite chromosomes are missing
*Unaffected globin genes are able to compensate for the affected genes
*Mild anemia – significant microcytosis*Normal lifespan
*Hb. Electrophoresis is normal.
Normal Hemoglobin Electrophoresis
*Hgb F (N = < 1% after age 1 year) *Hgb A2 (N = 2-3.5%)
*Hgb A1 (N=95.5-100%)
Causes: deletion
Type genotype Clinical
0 deletion Normal / --------
One deletion Thal : + heterozygous
-/ Silent carrier: mild hypochromic microcytic
anemia
Two deletions
Thal trait: + homozygous or 0 heterozygous
-/-
/--
Minor: mild hypochromic microcytic anemia
Three deletions
Hb H disease:0/+ double heterozygous
-/-- variable severity, but less severe than Beta Thal Major
deletion of all four a globin genes
Hb Bart’s; - homozygous
--/-- Hydrops Fetalis:In Utero or early neonatal death
complete absence of a globin synthesis
BETA-THALASSEMIA
Classification:1. ß- Thalassaemia major, very
sever.
2. Intermediate ß- thalassaemia
3. ß- Thalassaemia minor or trait.
1. Sever anaemia (2-3 g/dl)2. Enlargement of liver and spleen.3. Expansion of bones, leads to Bone
deformities.
Beta-thalassemia Major
Causes: one point mutation
Type genotype Clinical
0 mutation Normal /
Minor point mutation
Minor: Trait0 heterozygousOr+ heterozygous
/0
/+Minimal anemia; no treatment indicated
Two mutations
IntermediaDouble distinct mutation
0/+ severe heterozygoteCan be a spectrum; most often do not require chronic transfusions
Severe gene mutations
Major+ homozygous(double) Or0 homozygous (double)
+/+
0/0
Cooley’s AnemiaHomozygous minor point mutation Need careful observation and intensive treatment
The classification of Beta Thalassemias
• Laboratory findings:*Hemoglobin as low as 2-3 g/dl
*Markedly microcytic/hypochromic*Marked anisocytosis and poikilocytosis*Basophilic stippling and polychromasia
*Hemoglobin electrophoresis –90% Hb F and increased Hb A2
*HPLC: confirmatory test
Of moderate severity (Hb 7-10 g/dl). The patient may show bone deformity, enlarged liver and spleen.
Beta-thalassemia intermedia
-This is usually symptomless, but mild anaemia may occur.
- Normal iron, ferritin, TIBC- Prenatal counseling.
(25% risk rate if both partners carry beta thalassemia minor).- Hb. Electrophoresis:
4-7 % Hgb A2 92-95% Hgb A1
2-6 % Hgb F