Haematology - Overview

• Normal ranges for blood tests:
  • Male Haemoglobin: 130-180g/l
  • Female Haemoglobin: 110-180g/l
  • Haematocrit: 0.35-0.50
  • MCV: 77-87 fl
  • MCH: 25-33 pg
  • White Cell Count: 4.5-10 x 10⁹/l
  • Platelets: 150-400 x 10⁹/l
• Rhesus negative blood is considered the universal donor
• AB positive blood is considered the universal recipient
• "Cytosis" indicates too many cells, while "Paenia" indicates not enough

Iron Deficiency Anaemia

• Low haemoglobin results from insufficient iron, leading to microcytic, hypochromic red blood cells (RBCs)
• Causes include poor dietary intake, chronic blood loss (e.g., GI bleeding, heavy menstruation), and malabsorption (e.g., coeliac disease)
• Treatment involves oral iron supplements (ferrous sulphate or equivalent).
• Treatment involves addressing the underlying cause (e.g., treat GI bleed)
• Prevention includes adequate dietary iron intake (red meat, leafy greens) and monitoring at-risk groups (women with heavy periods, etc.)
• A condition in which there is a low level of haemoglobin in the blood due to a lack of iron, typically presenting as microcytic (small), hypochromic (pale) red blood cells

Anaemia of Chronic Disease

• A normocytic, normochromic anaemia commonly associates with inflammatory or chronic conditions (e.g., rheumatoid arthritis)
• Impaired iron metabolism and reduced RBC lifespan occur in the context of chronic disease or inflammation
• Treatment focuses on managing the underlying chronic disease
• Iron therapy or erythropoietin may be an option if severe, depending on cause
• Specific prevention not available; controlling the underlying chronic condition can help
• A normocytic (normal-sized) anaemia associates with chronic conditions (e.g., rheumatoid arthritis, chronic kidney disease) where inflammation impairs red blood cell production or shortens their lifespan

Vitamin B12 Deficiency Anaemia

• A macrocytic anaemia results in larger-than-normal RBCs
• Causes include inadequate intake (strict vegans without supplementation), lack of intrinsic factor (Pernicious Anaemia), and malabsorption (e.g., terminal ileum disease/resection)
• Treatment involves identifying the cause (e.g., pernicious anaemia)
• Lifelong vitamin B12 injections (intramuscular) are needed if absorption is impaired
• Prevention includes adequate dietary intake (animal proteins) and early detection of malabsorption issues
• A macrocytic anaemia caused by inadequate dietary B12 or poor absorption (e.g., due to lack of intrinsic factor, as in pernicious anaemia)

Pernicious Anaemia

• Autoimmune destruction of gastric parietal cells or intrinsic factor results in B12 malabsorption
• Treatment: Lifelong B12 injections should be administered every 3 months
• Direct prevention is not available; early diagnosis is crucial
• A type of B12 deficiency

Folate Deficiency Anaemia

• Another macrocytic anaemia caused by low folate levels
• Causes include poor dietary intake (especially in the elderly, alcoholism), increased demand (pregnancy), malabsorption (coeliac disease), and certain drugs (e.g., methotrexate)
• Treatment: Oral folate supplementation; also address the underlying cause (e.g., improved diet)
• Prevention: Balanced diet with folate-rich foods (green vegetables, fruits) and prophylactic folate in pregnancy
• Another macrocytic anaemia, results from low levels of folate (e.g., poor diet, malabsorption, or increased demand), causing large, immature red blood cells

Sickle Cell Anaemia

• Hereditary disorder (homozygous for sickle gene) causes RBCs to distort (“sickle”) under low oxygen, leading to vaso-occlusion and infarctions
• Mutation in the β-globin chain (HbS) is inherited in an autosomal recessive pattern
• Treatment: Pain management and hydration during sickle crises, hydroxycarbamide (hydroxyurea) to increase fetal haemoglobin, and blood transfusions or exchange transfusions in severe cases
• Prevention: Genetic counseling for at-risk couples and avoiding triggers (e.g., low oxygen environments)
• A hereditary condition where abnormal haemoglobin (HbS) causes red blood cells to become sickle-shaped under low-oxygen conditions, leading to infarctions and multiple organ issues

Thalassaemias

• Inherited disorders with reduced or absent production of alpha or beta globin chains lead to various severities of anaemia
• Genetic mutations are commonly found in Mediterranean, African, or Asian populations
• Treatment: Varies depending on severity, minor forms may need little/no treatment while major forms require regular blood transfusions, chelation therapy is used for transfusion-related iron overload
• Prevention: Genetic counselling/screening in high-prevalence communities
• A group of inherited blood disorders (commonly in Mediterranean, African, or Southeast Asian populations) where production of alpha or beta globin chains of haemoglobin is reduced, causing varying degrees of anaemia

Leukaemia

• Malignancies of white blood cells (WBCs) originate in bone marrow or lymphatic system
• Involves genetic and environmental factors, but the cause isn't fully clarified
• Types:
  • Acute (rapid onset, immature “blast” cells)
  • Chronic (slower progression, more mature cells)
  • Lymphocytic vs Myelogenous (type of WBC lineage)
• Treatment: Chemotherapy, radiotherapy, stem cell transplantation (depends on subtype)
• Prevention is not definitive. Early detection improves outcomes
• A cancer of blood-forming tissues (bone marrow and/or lymphatic system). Can be acute or chronic, and classified by the type of white blood cell affected (lymphocytic or myelogenous)

Myelodysplastic Syndrome (MDS)

• A bone marrow disorder where immature blood cells fail to mature properly, leading to low blood counts (pancytopenia)
• Often unclear cause; can be related to prior chemotherapy or radiation
• Treatment: Supportive care (transfusions), sometimes chemotherapy or stem cell transplant; the aim is control rather than cure in many cases
• Prevention: Not specifically preventable; early detection can guide management
• A disorder of the bone marrow where immature blood cells do not mature properly, leading to cytopenias (low blood counts) and risk of progression to leukaemia

Multiple Myeloma

• Cancer of plasma cells in the bone marrow leads to bone lesions, anaemia, and high calcium
• Cause isn't entirely known; associated with paraprotein production (Bence Jones protein)
• Treatment: Chemotherapy, steroids, bisphosphonates (to protect bones), stem cell transplant in suitable patients
• No direct methods of prevention; early symptom recognition (bone pain, fatigue) can help
• A cancer arising from plasma cells in bone marrow commonly associates with bone lesions, anaemia, hypercalcaemia, and characteristic paraprotein production (e.g., Bence Jones protein)

Lymphoma (Hodgkin & Non-Hodgkin)

• Malignancies of the lymphatic system with Hodgkin lymphoma distinguished by Reed-Sternberg cells
• Possibly viral triggers (e.g., EBV) are involved, alongside genetic predisposition
• Treatment: Chemotherapy and/or radiotherapy, monoclonal antibodies are used particularly for some Non-Hodgkin’s, and stem cell transplant may be considered in certain cases
• No specific prevention. Early detection is key
• Cancers of the lymphatic system; characterized by lymph node enlargement, with Hodgkin lymphoma identified by Reed-Sternberg cells

Haemophilia A & B

• Inherited bleeding disorders; Haemophilia A (Factor VIII deficiency), B (Factor IX deficiency)
• X-linked recessive mutations occur in clotting factor genes
• Treatment: Factor replacement therapy (VIII or IX) may be administered, desmopressin (DDAVP) can help mild Haemophilia A, avoid trauma, and use local haemostatic measures should be used in dental procedures
• Prevention: Genetic counselling may be considered for patients with a family history
• Haemophilia A: a hereditary bleeding disorder caused by deficiency of Factor VIII, leading to difficulty forming stable blood clots, usually X-linked
• Haemophilia B (Christmas Disease): a hereditary deficiency of Factor IX, similarly leading to impaired clotting and prolonged bleeding, also usually X-linked

von Willebrand Disease (VWD)

• The most common inherited bleeding disorder is caused by deficient or defective von Willebrand factor, is crucial in platelet adhesion
• Mostly autosomal dominant inheritance occurs and severity varies
• Treatment: Desmopressin (DDAVP) may be administered for mild types, von Willebrand factor concentrates and Factor VIII supplements may also be needed, and antifibrinolytics (e.g. tranexamic acid) may also be used
• No direct method of prevention; awareness and proper management of bleeding risk
• The most common inherited bleeding disorder, involving deficiency or dysfunction of von Willebrand factor, a protein critical for platelet adhesion

Factor V Leiden Thrombophilia

• An inherited hypercoagulable condition that is caused by abnormal Factor V, leading to increased clotting risk
• Genetic mutation occurs in Factor V
• Treatment: Anticoagulants may be administered if clotting events occur or prophylactically in high-risk situations
• Prevention includes awareness, testing at-risk relatives, and prophylaxis in risk scenarios (e.g., surgery)
• An inherited predisposition to excessive clotting (hypercoagulability) due to a mutated Factor V that resists normal breakdown

Drugs, Treatments, and Tests

• Oral Iron Supplements
  • Used for iron deficiency anaemia
  • Replenishes body’s iron stores to restore haemoglobin production
• Folate Supplements (Folic Acid)
  • Used for folate deficiency anaemia, sometimes alongside methotrexate therapy
  • Provides folate needed for DNA synthesis in RBC production
• Vitamin B12 Injections (Hydroxocobalamin)
  • Used for B12 deficiency anaemia (especially pernicious anaemia)
  • Bypasses malabsorption by delivering B12 intramuscularly
• Blood Transfusions
  • Used for severe anaemia or acute blood loss
  • Replaces RBCs (and sometimes plasma, platelets) to quickly increase oxygen-carrying capacity
• Chemotherapy
  • Used for various blood cancers (e.g., leukaemia, lymphoma, myeloma)
  • Targets rapidly dividing cells (including cancerous cells)
• Radiotherapy
  • Used for certain lymphomas and other malignancies
  • Uses high-energy radiation to damage and kill cancer cells
• Stem Cell (Bone Marrow) Transplant
  • Used for some acute leukaemias, myeloma, lymphoma, and MDS
  • Resets the patient’s bone marrow by infusing healthy stem cells after high-dose chemotherapy
• Bisphosphonates
  • Used for multiple myeloma to reduce bone breakdown (also used in osteoporosis)
  • Inhibits osteoclast-mediated bone resorption
• Factor VIII or IX Replacement
  • Used for Haemophilia A (VIII) and Haemophilia B (IX)
  • Replaces the deficient clotting factor, improving clot formation
• Desmopressin (DDAVP)
  • Used for Mild Haemophilia A, von Willebrand Disease
  • Stimulates release of factor VIII and von Willebrand factor
• Tranexamic Acid (TXA)
  • Used for antifibrinolytic agent in bleeding disorders, especially post-dental extraction
  • Prevents clots from being broken down too quickly, reducing bleeding
• Warfarin
  • Used for anticoagulation (long-term) in patients with high thrombosis risk (e.g., atrial fibrillation)
  • Vitamin K antagonist, reduces synthesis of certain clotting factors and INR is monitored
• Heparin (Unfractionated or Low Molecular Weight)
  • Used for short-term anticoagulation (e.g., hospital settings)
  • Enhances activity of antithrombin III, inhibiting thrombin and factor Xa
• DOACs (Dabigatran, Rivaroxaban, etc.)
  • Used for alternative to warfarin for stroke prevention in atrial fibrillation, treatment of venous thromboembolism
  • Dabigatran: Direct thrombin inhibitor
  • Rivaroxaban (and others): Direct factor Xa inhibitors, monitoring not via INR, Timing of dosing may be adjusted for dental procedures
• APTT (Activated Partial Thromboplastin Time)
  • Used to test Intrinsic and common clotting pathway (e.g., haemophilia A/B)
  • Laboratory test measuring clot formation time
• PT/INR (Prothrombin Time/International Normalised Ratio)
  • Used to test Extrinsic and common clotting pathway
  • Monitors warfarin therapy efficacy/safety
• ESR (Erythrocyte Sedimentation Rate)
  • Used for non-specific indicator of inflammation/disease
  • Measures the rate at which RBCs settle in a tube over time, elevated in many conditions

Explore normal ranges for blood tests and the causes, symptoms, and treatments for iron deficiency anemia. Learn about microcytic, hypochromic red blood cells and the importance of dietary iron. Understand key blood facts.