Introduction to Haematology and Anaemia - THEP2 (2).ppt

RCSI Royal College of Surgeons in Ireland Coláiste Ríoga na Máinleá in Éirinn Introduction to Haematology and Anaemia Class Course Lecturer Date Year 1 Pathology Professor Siobhan Glavey Professor Abdullah Darwish 1st October 2023 LEARNING OUTCOMES • • • • • • • • Define anaemia. Describe the f...

RCSI Royal College of Surgeons in Ireland Coláiste Ríoga na Máinleá in Éirinn Introduction to Haematology and Anaemia Class Course Lecturer Date Year 1 Pathology Professor Siobhan Glavey Professor Abdullah Darwish 1st October 2023 LEARNING OUTCOMES • • • • • • • • Define anaemia. Describe the function of the bone marrow. Describe the clinical consequences of anaemia. Describe the classifications of anaemia, laboratory and pathophysiological Describe the causes of macrocytic, microcytic and normocytic anaemia Describe the laboratory investigations and the significance of abnormal results in the diagnosis of anaemia. Describe the causes of Fe, B12 and Folate deficiency. Describe the causes of marrow replacement/reduced function. ANAEMIAS • Today’s lecture will outline some types of anaemia other than haemolytic anaemias • Fe deficiency • B12 deficiency • Folate deficiency • Aplastic anaemia Definition of anaemia: Reduction in Haemoglobin due to a disorder of globin or heme Haemoglobin < 12g/dL in non pregnant women Haemoglobin < 13g/dL in men BLOOD IS MADE IN THE BONE MARROW GENERATION OF BLOOD CELLS ANAEMIA • Anaemia is a condition in which the number of red blood cells or their oxygen-carrying capacity is insufficient to meet physiological needs which vary by age, sex, altitude, smoking and pregnancy status • The WHO criteria for anaemia is Haemoglobin levels <12g/dL in non-pregnant women and <13g/dL in adult males • Anaemia in pregnancy is defined as a Haemoglobin concentration of 11g/dL • Severe anaemia Hb <7.0g/dL ANAEMIA IS A GLOBAL HEALTH PROBLEM • It is a major global public health problem • Estimated prevalence of anaemia in India is 42% in women 15-59 years, 30% in men 15-59 years • Disproportionally affects women and girls globally due to iron deficiency and inadequate access to healthcare Journal of Haematology and Oncology Burden of anemia and its underlying causes in 204 countries and territories, 1990–2019: results from the Global Burden of Disease Study 2019 CLASSIFICATION OF ANAEMIA • Morphological classification • Aetiological classification THE FULL BLOOD COUNT Haemoglobin Platelet count White cell count Neutrophils Lymphocytes Eosinophils Basophils Monocytes VIDEO FOR FULL BLOOD COUNT • https://www.youtube.com/watch?v=j7PJrUFciec MORPHOLOGIC CLASSIFICATION Microcytic anaemia MCV < 80fl) Macrocytic anaemia MCV >100fl) Normocytic anaemia (MCV 80-100fl) Iron deficiency anaemia - Menorrhagia is major cause Megaloblastic anaemia - B12 deficiency - Folate deficiency Anaemia of chronic disease Thalassemia Non megaloblastic - Liver disease - Haemolytic anaemia - Alcohol excess - Myelodysplasia - Hypothyroidism Aplastic anaemia Chronic kidney disease (EPO deficiency) Sideroblastic anaemia MORPHOLOGICAL CLASSIFICATION • This is based on the mean corpuscular haemoglobin • MCV definition - The mean corpuscular volume, or mean cell volume, is a measure of the average volume of a red blood corpuscle. DEFINITIONS • Mean corpuscular haemoglobin – average amount of haemoglobin in each red cell • Mean corpuscular haemoglobin concentration – average concentration of haemoglobin inside a group of red blood cells (31-37g/dL) • Reticulocyte – immature red blood cell, larger than mature red blood cells and therefore if present in the blood can increase the MCV – Reticulocytes usually reside in the bone marrow but in states of erythroid stress are pushed into the blood before they are ready to be mature cells – This is why you can see a high reticulocyte count in anaemia, as the bone marrow tries to compensate PATHOPHYSIOLOGIC CAUSES OF ANAEMIA • Failure to make red cells: Marrow problem • Lack of haematinics: Iron, B12, Folate e.g. dietary deficiency, malabsorption, loss • Increased loss of red blood cells e.g. bleeding • Increased destruction of red cells: Haemolysis • Chronic disease HISTORY TAKING IN ANAEMIA • Diet history – Vegetarian can increase risk of IDA • • • • • • Chronic blood loss – can you think of examples? Hereditary – Sickle Cell Disease, Thalassemia Alcohol Renal disease Chronic diseases – rheumatoid arthritis History of systemic symptoms – B symptoms – night sweats, weight loss, itch • Recent travel MENORRHAGIA HISTORY TAKING • Detailed history – – – – – – – • • • • • Menarche Length of cycle and bleeding days Pads/tampons Soaks clothes Days off work/school Previous iron deficiency Other bleeding issues Be sensitive and professional Encourage self assessment Keep a diary Cultural and social norms Family norms can mask heavy periods KNOWYOURFLOW.IE MORE DETAILED BLOOD TESTS IN ANAEMIA • • • • • • • • • • • • Reticulocyte count Blood film ESR – old fashioned test not clinically useful B12 and folic acid Liver function – bilirubin Renal function EPO level Iron profile LDH, uric acid Hb electrophoresis if you suspect hereditary anaemia Bone marrow test Direct antibody test (DAT) used to be called Coombes test Review CALPATH on this topic!!!! CAUSES OF IDA • Dietary • Malabsorption – Coeliac disease – Crohn’s disease – Intestinal resection • Loss e.g. – GIT e.g. Duodenal or gastric ulcer, Ca colon – Menorrhagia • Increased requirements requirement Childhood, Pregnancy TREATMENT OF IDA • Find out the underlying cause and manage that – Iron will continue to drop until this is addressed – Ulcer management – Menorrhagia management – OCP, coil, tranexamic acid • Oral iron replacement • IV iron replacement in cases where iron deficiency is severe (Hb <7) and oral iron is not tolerated or will not work fast enough • Avoid blood transfusion if at all possible • Only in cases where patient is severely symptomatic (e.g. coronary disease) or Hb < 5 • REMEMBER TO FOLLOW THE PATIENT UP!!! INVESTIGATIONS IN MEGALOBLASTIC ANAEMIA • Increased MCV and MCH • Low RBC, WBC and platelets (only in severe cases) • Blood film – oval macrocytic red cells – Hypersegmented neutrophils • • • • LDH is raised Serum B12 and or folate reduced Normal B12 level 160-200ng/L folate 2-15ug/L) Serum methylmalonic acid (MMA) and homocysteine are elevated in B12 def, only HC is elevated in folate def – we don’t use these tests much in Ireland • Antibodies to intrinsic factor ABSORPTION OF B12 • B12 from diet (milk eggs and meat) combines with intrinsic factor (secreted by gastric parietal cells) • The B12 intrinsic factor complex are absorbed in the terminal ileum PERNICIOUS ANAEMIA PERNICIOUS ANAEMIA This is one cause of B12 deficiency and therefore can cause megaloblastic anaemia CAUSES OF B12 DEFICIENCY • Lack of B12 in diet – Main sources are liver, beef, sardines, nuts, wholegrain breads • Inability to absorb B12 – Pernicious anaemia which is due to antibodies to intrinsic factor or to the gastric parietal cell – Patient cannot absorb any oral B12 – Must receive lifelong parenteral B12 replacement usually as intramuscular injections every 3 months • Some patients with Coeliac disease also do not absorb B12 very well • Conditions of the stomach that interfere with gastric parietal cells – e.g. surgery • Conditions of the bowel that cause the terminal ileum to be damaged e.g. Crohn’s disease FOLATE • Absorbed in duodenum and upper jejunum • What are the causes of folate deficiency? CAUSES OF FOLATE DEFICIENCY • • • • Dietary Alcoholism Malabsorbtion Increased requirements – pregnancy, lactation, haemolytic anaemia, chronic blood loss • Drugs – anti seizure medications such as phenytoin TREATMENT OF FOLATE DEFICIENCY ORAL FOLIC ACID CAUSES OF REDUCED BONE MARROW FUNCTION • Replacement of bone marrow by anything that invades the bone marrow – Cancer primary to the bone marrow – Cancer that has metastasized to the bone marrow – Infection – granulomas • Fibrotic processes – Myelofibrosis – can be primary of secondary • Bone marrow failure syndromes and conditions – e.g. aplastic anaemia, myelodysplasia SUMMARY • Anaemia is global health burden that disproportionately affects women and girls • Diagnosis requires detailed history and exam • Know how in interpret the FBC • Know common causes of macrocytic, microcytic and normocytic anaemia • How to diagnose and treat iron deficiency