hematology (1) the blood and bone marrow, abnormal blood count, anemias: an overview
TRANSCRIPT
Hematology Course:an overview of Clinical
Hematology
Dr. Ahmed Elshebiny , MDDr. Ahmed Elshebiny , MDLecturer of Internal MedicineLecturer of Internal Medicine
Faculty of Medicine, Menoufyia UniversityFaculty of Medicine, Menoufyia University
Former Clinical Research FellowFormer Clinical Research Fellow,,Joslin Diabetes Center, Harvard UniversityJoslin Diabetes Center, Harvard University
Course includes1. Hematology an Overview : The blood and bone marrow2. Clinical Hematology : The full blood count3. Anemia : a Clinical approach4. Deficiency anemias5. Hemolytic anemia : Acquired6. Hemolytic anemia : inherited7. Bone marrow failure syndromes ( aplastic, myeloysplastic, PNH)8. Hypoproliferative anemias (of chronic disease)9. Myeloproliferative disorders10. Leukemias11. Lymphomas & Myelomas 12. Porphyria & Hemochromatosis13. Leukocyte disorders14. Interpretation of standard hematologic tests
Structure and Function
Blood as a circulatory fluid A protein rich fluid called plasma in which
cellular elements are suspended Carrier of O2 and CO2
Carries nutrients Carries waste Hormones Immunity Hemostasis
Blood is continuously renewed
The Bone Marrow is the blood Factory
May be exposed to damage or failure
Spleen? Blood filter Immunity
Red blood cells A nucleated Diameter and thickness Membrane Metabolism
Red cell membrane Phospholipid bilayer Intracellular protein network 50% cholestrol Membrane proteins
( glycophorin c and band 3) Reticuloproteins
( spectrin , actin, ankyrin)
Hemoglobin Tetramer of 4 globin chains (proteins) Each with a heme group containing iron Can be distinguished by electrophoresis Chain types
Alpha Beta Gamma Delta Zeta and epsilon are embryonic
Fetal and neonatal hemoglobins
HB and MCV values with age & sex
Haemopooiesis Yolk sac ( 3 rd week) Liver and spleen ( 6 wk to 7 months) Bone marrow Red marrow & yellow marrow Extramedullary ---- When?
Aplastic Anemia
Bone marrow aspiration and biopsy
Bone marrow aspiration
P.N.H
Hematology Course (2):Clinical Hematology
Manifestations of blood diseases Anemia High hemoglobin Bleeding Thrombosis Infections Lymphadenopathy Splenomegaly
Full blood count Common investigation Can point to hematological disorders Cornerstone of hematological diagnosis Manual or automated Automated counting and sizing by different methods
e.g. ( Aperture impedance) They also measure the hemoglobin by
spectrophotometry Some other parameters are calculated ( MCH,
MCHC) The automated analyzers can diffrentiate leukocyte
N.B. 5% of the normal population lie outside the
normal range Race may affect the CBC Be careful of artifacts
Anemia Definition Morphological approach Etiological( kinetic ) approach RBCs in the blood film
Polycythemia True Polycythemia( Primary and secondary) Relative ( decreased plasma volume)
Leucocytosis Examine the differential count Examine a blood film Commonest is neutrophilia
WBCs 5 WBCs line ( diffrential)
Neutrophils Lymphocytes Monocytes Eosinophils Basophils
Neutropenia Clinically evident when ANC < 500 Congenital and acquired
Congenital ( e.g Kostman;s syndrome and cyclic neutropenias)
Most cause of acquired neutropenia is drugs
Drugs associated with neutropenia Anticonvulsants ---- phenytoin Antithyropid ------- carbimazole Phenothiazines ------ carbamazepine Antibacterial -------- phenylbutazone Anti-inflammatory ------ co trimoxazole Cytotoxic Others ----- gold, penicillamine, imipramine
Neutrophil disorders
NetrophiliaNeutroppenia
Infections ( bact, fungal)Surgery, BurnsInfarctions Inflammation ( gout, RA, IBD)Malignancy (CML)Physiological
Infections( viral, salmonella, protozoal, malaria) DrugsAutoimmuneAlcoholCongenital
Lymphocytic count disorders
LymphocytosisLymphopenia
Infections ( viral, pertussis, glandular fever) Lymphoproliferative ( CLL, lymphoma )Post splenectomy
Infections( recent viral) (immunosuppressive, cortisone)Autoimmune & CT diseasesSarcoidosisChronic renal failureCongenital : severe combined immunodifficiency
Eosinophils
EosinophiliaEosinopenia
Allergy ( asthma, eczema)Infections ( Helminths, viral)Skin disease C.T disease e.g PAN Malignancy ( solid tumors and lymphomas)Gold therapy
Acute inflammation SteroidsCatecholamines
Basophils
Basophilia ( rare)basopenia
Inflammation ( Acute hypersensitivity, IBD) Iron difficiencyMyeloproliferative disorders ( Polythycemia, CML)
Hyperthyroidism
Monocytosis Viral and fungal infections T.B infection C.T diseases Inflammatory bowl disease Myeloproliferative Chronic Myelomonocytic leukemia ( one of
MDS) Malignancy e.g solid tumors
Platelets (thrombocytopenia) Spurious Increased consumption Decreased production
Platelets (thrombocytosis) Reactive Primary
Blood film Abnormal shape ( poikilocytosis) Spherocytes Target cells Polychromasia Dimorphic film Lobulation and toxic granulation A typical cells Blast cells Malaria others
Hematology Course (3):Clinical Hematology
Anemia is operationally defined as a reduction in one or more of the major RBC measurements:
hemoglobin concentration, hematocrit, or RBC count
Keep in mind these are all concentration measures
…most accurately measured by obtaining a RBC mass via isotopic dilution methods.
Definition:
Kinetic approach to anemias Decreased erythrocyte production
Decreased erythropoietin production Inadequate marrow response to erythropoietin
Erythrocyte loss Hemorrhage Hemolysis
Normal blood film
Morphological approach
Reticulocytes Increased reticulocytes
(greater than 2-3% or 100,000/mm3 total) are seen in blood loss and hemolytic processes, although up to 25% of hemolytic anemias will present with a normal reticulocyte count due to immune destruction of red cell precursors.
Retic counts are most helpful if extremely low (<0.1%) or greater than 3% (100,000/mm3 total).
Reticulocytes
Low MCV Iron Deficiency Thalassemia Lead poisoning Sideroblastic Anemia Anemia of chronic disease
Iron difficiency anemia Thalassemia
Thalassemia
Sickle cell anemia
Spherocytosis
Hemolytic anemia
Normocytic anemia Causes Approach Reticulocytic count Coomb’s test
Macrocytic anemia
B 12 and folate deficiency
References Merck manual : online textbook
E-medicine , online textbook , specialties,. Bethesda Handbook of Clinical Hematology Problem solving in Hematology Essential Revisoin notes for MRCP 2009 Kumar & Klark : Clinical Medicine 2009 Davidson’s : Clinical and practice of Medicine 1999 Ganong’s physiology 2010 Other Web Resources & books