The Haemolytic Anaemias PDF
Document Details
Uploaded by OptimisticSwaneeWhistle
University of Technology, Jamaica
Tags
Summary
These lecture notes cover the haemolytic anaemias. They describe definitions, clinical features, diagnosis, treatment options, and classifications. The notes also discuss aspects of extravascular and intravascular haemolysis and laboratory tests associated with the diagnosis, as well as intrinsic and extrinsic haemolytic anaemias. This document is well suited for medical students or professionals.
Full Transcript
The Haemolytic Anaemias Outline: ◼ Definition of Haemolytic Anaemias ◼ General Clinical Features of a Haemolytic Anaemia ◼ The Diagnosis of Haemolytic Anaemias ❑ Routine Laboratory Tests ❑ Confirmatory Laboratory Tests ◼ Treatment Options utilised for Haemolytic Anaemias...
The Haemolytic Anaemias Outline: ◼ Definition of Haemolytic Anaemias ◼ General Clinical Features of a Haemolytic Anaemia ◼ The Diagnosis of Haemolytic Anaemias ❑ Routine Laboratory Tests ❑ Confirmatory Laboratory Tests ◼ Treatment Options utilised for Haemolytic Anaemias ❑ How the Laboratory tests are affected during treatment ◼ Classification of Haemolytic Anaemias (next class) Definition of a Haemolytic Anaemia: ◼ RBC production > RBC destruction = Normal ◼ RBC destruction > RBC production (& BM compensation)= Haemolytic State ◼ RBC destruction > RBC production (& BM exceeded) = Haemolytic Anaemia Senescent RBC’s: ◼ At 100 – 120 dys., Hb in the RBC is broken down Extravascularly &/or Intravascularly ❑ Extravascular Haemolysis results in the orderly breakdown of Hb into fundamental reusable structures ◼ Responsible for 90 – 95% of total Hb broken down ◼ XS haemolysis is seen clinically as Jaundice Extravascular Haemolysis: WITHIN THE R.E.S. (eg. Spleen) Hb HEME GLOBIN CHAINS Iron Protoporphyrin Amino Acid Pool Bilirubin Transferrin CO Bilirubin (expired air) Glucoronides Stercobilinogen Urobilinogen RECYCLED RECYCLED FOR FOR PROTEIN ERYTHROPOIESIS EXCRETION SYNTHESIS Definition of a Haemolytic Anaemia: ◼ Intravascular Haemolysis results in the liberation of Hb ❑ Responsible for 5 – 10% of total Hb broken down ❑ Haptoglobins pick up limited amounts of Hb ◼ once level is exceeded Hb can no longer be recycled ❑ XS haemolysis is seen clinically as Hburia, Haemosiderinuria General Clinical Features of a Haemolytic Anaemia: ◼ Signs & Symptoms of any Anaemia: ❑ S.O.B., fatigue, pale mucous membranes, dizziness etc… ◼ Signs & Symptoms of a Haemolytic Anaemia: ❑ Jaundice – localized or systemic (XS Extravascular) ❑ Hbemia, Hburia, Haemosiderinuria (XS Intravascular) ❑ ‘Bossing’ of the Bone (sign of BM compensation; seen in some anaemias) The Diagnosis of Haemolytic Anaemias: Routine Laboratory Tests ◼ ↓ Hb, PCV/Hct & RBC Count ❑ causes the generalised symptoms of anaemia ◼ Normal values for RBC Indices (N/N*) ❑ Morphologically classifies the anaemia ◼ Reticulocyte Count ↑ ❑ measures the rate of RBC production ◼ Slide Analysis: Schistocytes, specific poikilocytosis ◼ ↑ Bilirubin (total), LDH, Haptoglobins, DAT +/- * Values vary with HS & Thalassemias The Diagnosis of Haemolytic Anaemias: Confirmatory Laboratory Tests Once a haemolytic anaemia has been established, which one is it? ◼ signs & symptoms ◼ clues maybe obtained from the slide analysis (RBC Morphology) Specific Confirmatory Tests are chosen to demonstrate a specific haemolytic anaemia Treatment Options utilised for Haemolytic Anaemias 1. Transfusions of Blood products (↑ RBC mass) a) concurrent monitoring of Fe2+ status & Hb levels 2. Splenectomy (in some cases to cease XS extravascular haemolysis) 3. Analgesics (in some cases for pain management) 4. Supportive therapy (to encourage erythropoiesis) a) folic acid 5. exposure to UV light (alleviate jaundice) Classification of Haemolytic Anaemias Intracorpuscular/Intrinsic Defects Extracorpuscular/Extrinsic Defects -‘Forces’ within the RBC cause ↑ RBC -‘Forces’ outside the RBC cause ↑ RBC destruction destruction Classification of Haemolytic Anaemias Haemolytic Anaemias Intrinsic Defects Extrinsic Defects Acquired Hereditary Immune & Non-Immune - PNH Haemoglobinopathies Membranopathies -HS Enzymopathies Qualitative Quantitative -HE -G6PD -SS + trait -Thalassemias -others -PK -CC + trait α β -others The Haemolytic Anaemias ◼ Read up the aetiology, pathophysiology, diagnosis & treatment. ❑ We will be doing the Intrinsic Hereditary Haemolytic Anaemias first and then the Acquired Hereditary Haemolytic Anaemias. ❑ You will be required to read up on the Extrinsic Haemolytic Anaemias…..we will do a selected few in this category. Intrinsic Hereditary Haemolytic Anaemias: ◼ Membranopathies: The RBC membrane is defective in component(s) of the RBC cytoskeleton forming a defective RBC. Eventually haemolysis is increased so as to remove non-functional cells. ◼ Enzymopathies: Defective metabolic pathways make RBC susceptible to stress & produces morphological changes which are not tolerated by Spleen. ◼ Haemoglobinopathies: Substitutions in Amino Acids and Deletions Globin chains produce a defective RBC. Intrinsic Aquired Haemolytic Anaemia: ◼ PNH: ❑ Acquired defect of all blood cells ❑ Cells become sensitive to Complement activity Extrinsic Acquired Haemolytic Anaemias: ◼ Immune: ❑ Allo-Immune ❑ Auto-Immune ❑ Drug-Induced ◼ Non-Immune: ❑ Intracellular Infections ❑ Extracellular Infections ❑ Mechanical Processes ❑ Chemical & Physical Stimuli
