DIMS Lectures Hematology PDF

Here is the complete pdf lecture of hematology by Dr. Tahir Malik

Introduction to Haematology

Haematology is the branch of medicine that focuses on the study of blood, blood-forming organs, and disorders related to hematopoiesis. It encompasses the physiology, pathology, and clinical aspects of blood and its components, including red blood cells (RBCs), white blood cells (WBCs), platelets, plasma, and coagulation mechanisms. Understanding haematology is vital for medical students and healthcare professionals to diagnose, manage, and treat a wide range of hematologic conditions effectively.

Composition and Function of Blood

Blood is a specialized fluid that plays a crucial role in oxygen transportation, immune defense, homeostasis, and waste removal. It consists of several components:

1. Plasma

Plasma is the liquid portion of blood, accounting for approximately 55% of its volume. It contains:

• Water (90%) - Acts as a solvent and medium for transporting substances.
• Proteins
  • Albumin: Maintains oncotic pressure and transports substances.
  • Globulins: Play a role in immunity (antibodies and clotting factors).
  • Fibrinogen: Essential for clotting.
• Electrolytes - Sodium, potassium, calcium, chloride, bicarbonate.
• Hormones and Enzymes - Regulate physiological processes.
• Metabolic Waste Products - Urea, creatinine, bilirubin, carbon dioxide.

2. Red Blood Cells (Erythrocytes)

RBCs are responsible for oxygen transport. Important features include:

• Hemoglobin (Hb): A protein that binds oxygen in the lungs and delivers it to tissues.
• Biconcave Shape: Increases surface area for gas exchange.
• No Nucleus: Enhances flexibility and lifespan (~120 days).
• Production: Occurs in bone marrow (erythropoiesis), stimulated by erythropoietin from the kidneys.

3. White Blood Cells (Leukocytes)

Leukocytes are critical for immune defense and are classified into:

Granulocytes

• Neutrophils: First responders to infection, phagocytic.
• Eosinophils: Combat parasitic infections and allergic reactions.
• Basophils: Release histamine during allergic responses.

Agranulocytes

• Lymphocytes:
  • B-cells: Produce antibodies.
  • T-cells: Coordinate immune responses.
  • Natural Killer (NK) cells: Destroy infected or cancerous cells.
• Monocytes: Differentiate into macrophages to engulf pathogens.

4. Platelets (Thrombocytes)

Platelets play a pivotal role in clotting and wound healing:

• Aggregate at injury sites to form a platelet plug.
• Interact with clotting factors to stabilize the clot.
• Lifespan: 7-10 days.

Common Haematological Disorders

1. Anemia

A condition characterized by low RBC count or hemoglobin levels. Types include:

• Iron-Deficiency Anemia: Most common; caused by inadequate iron intake or chronic blood loss.
• Megaloblastic Anemia: Due to vitamin B12 or folate deficiency.
• Hemolytic Anemia: Premature destruction of RBCs.
• Aplastic Anemia: Bone marrow failure to produce RBCs.
• Sickle Cell Anemia: Genetic disorder causing RBC deformity and reduced oxygen transport.

2. Leukemia (Blood Cancer)

Leukemia is a malignancy affecting WBCs. Types include:

• Acute Lymphoblastic Leukemia (ALL): Common in children.
• Acute Myeloid Leukemia (AML): Aggressive, more common in adults.
• Chronic Lymphocytic Leukemia (CLL): Slow progression, affects B-lymphocytes.
• Chronic Myeloid Leukemia (CML): Associated with the Philadelphia chromosome.

3. Coagulation Disorders

• Hemophilia: Genetic deficiency of clotting factor VIII (Hemophilia A) or IX (Hemophilia B).
• Von Willebrand Disease: Most common inherited bleeding disorder.
• Disseminated Intravascular Coagulation (DIC): Excessive clotting followed by severe bleeding.

4. Thrombocytopenia

A low platelet count leading to increased bleeding risk. Causes include:

• Immune Thrombocytopenic Purpura (ITP): Autoimmune destruction of platelets.
• Thrombotic Thrombocytopenic Purpura (TTP): Platelet aggregation leading to organ damage.

5. Polycythemia

Excess RBCs leading to thickened blood and increased clotting risk. Types include:

• Primary Polycythemia (Polycythemia Vera): Bone marrow disorder.
• Secondary Polycythemia: Due to hypoxia or tumors producing excess erythropoietin.

Diagnostic Approaches in Haematology

Diagnosing blood disorders involves several key laboratory investigations:

• Complete Blood Count (CBC): Measures RBC, WBC, and platelet levels.
• Peripheral Blood Smear: Examines cell morphology.
• Bone Marrow Aspiration and Biopsy: Assesses bone marrow function.
• Coagulation Tests: PT, APTT, INR for clotting abnormalities.
• Flow Cytometry: Identifies leukemia and lymphoma markers.
• Iron Studies: Evaluates anemia causes.

Treatment Strategies for Haematological Disorders

1. Supportive Care

• Iron, Vitamin B12, and Folate Supplements: For nutritional anemias.
• Blood Transfusions: For severe anemia and blood loss.

2. Pharmacological Treatment

• Erythropoietin Stimulating Agents (ESAs): For chronic kidney disease-related anemia.
• Chemotherapy & Radiation Therapy: For leukemia and lymphoma.
• Anticoagulants (Warfarin, Heparin): For thrombosis prevention.
• Clotting Factor Replacement: For hemophilia.

3. Advanced Therapies

• Bone Marrow Transplantation: For leukemia, lymphoma, and aplastic anemia.
• Targeted Therapy & Immunotherapy: Including monoclonal antibodies for leukemia treatment.

⚠Caution!
Please Make Sure you are using standard internet browser with a very good internet connection speed.

📌Stay Updated!