ERYTHROCYTE II(Anemia Polycythemia) HMIM BLOCK 224 Dr. ShaikhMujeeb Ahmed Assistant Professor AlMaarefa College
Objectives • Classify anemia • Differentiate between different types of anemia • Write normal values for RBC, Hb, HCT [PCV], MCV, MCH, MCHC • Define Polycythemia • Differentiate between Primary Secondary Polycythemia • Summarize the effect of anemia & polycythemia on the body
ANEMIA • What is Anemia? • Anemia means - Decreased hemoglobin - Decreased RBC count - Decreased Hematocrit [PCV] • Therefore, decreased O2 carrying capacity of blood.
CAUSES OF ANEMIA • Nutritional Anemia It is caused by dietary deficiency of factors needed for Erythropoiesis. 1.Dietary Deficiency of Iron Iron deficiency anemia is called microcytic hypochromic anemia as RBC is small with less Hemoglobin.
Nutritional Anemia 2.Megloblastic Anemia • It is due to deficiency of vitamin B12 or folic acid. • Vitamin B12 is essential for normal RBC maturation. • Vitamin B12 deficiency leads to Megloblastic Anemia [RBC size is large].
Anemia • Pernicious Anemia - It is due to deficiency of Intrinsic factor produced by Parietal cells of stomach. - Intrinsic factor is necessary for absorption of Vitamin B12. - Vitamin B12 is absorbed from intestinal tract [terminal ileum] when Vitamin B12 is bound to intrinsic factor. - Pernicious Anemia is megloblastic anemia.
ANEMIA 3. Aplastic Anemia It is caused by failure of bone marrow to produce RBC even though all necessary nutrients for Erythropoiesis are available. Causes of Aplastic Anemia -Excessive exposure to X-ray -Exposure to radiation, e.g. bomb blast -Chemotherapy for Cancer -Drugs
ANEMIA 4. Hemolytic Anemia It is caused by rupture [breakdown] of RBC. Causes of Hemolytic Anemia -Malaria -Sickle Cell Anemia [Hemoglobin β chain is defective where valine replaces glutamate at position 6 in this amino acid chain].RBC is sickle shaped -Mismatched blood transfusion -Drugs
ANEMIA 5. Renal Anemia Anemia in Renal [kidney] disease is due to decreased Erythropoietin secretion from the kidney. It leads to decreased RBC production.
ANEMIA 6 .Hemorrhagic Anemia - It is caused by losing a lot of blood. - Acute Loss of blood e.g. car accident. - Chronic Loss of blood e.g. bleeding peptic ulcer, excessive menstrual flow.
ANEMIA • How to diagnose microcytic hypochromic anemia [iron deficiency] and macrocytic [megloblastic] which is vitamin B12 deficiency anemia? We see • Hemoglobin, RBC, PCV [Hematocrit] • MCV [Mean Cell Volume] • MCH [Mean Concentration of Hemoglobin] • MCHC [Mean Cell Hemoglobin Concentration]
ANEMIA We will define MCV, MCH, MCHC • MCV – it is the volume of average RBC - Normal MCV = 90 fL or 90 μ3 [MCV > 95 fL are called macrocyte] [MCV < 80 fL are called microcyte] • MCH – it is mean concentration of Hemoglobin in each RBC. - Normal MCH = 30 picogram [pg] • MCHC – it is hemoglobin present per 100ml of RBC - Normal MCHC = 30 gram/100ml of RBC
ANEMIA Microcytic Hypochromic Anemia Or Iron Deficiency Anemia • In iron deficiency anemia Hemoglobin RBC Hematocrit MCV MCH MCHC
ANEMIA Macrocytic [Megloblastic] Anemia Vitamin B12 or folic acid deficiency Hemoglobin RBC Hematocrit MCV MCH Normal MCHC Normal It is called Macrocytic Normochromic Anemia.
NORMAL VALUEs & FORMULAE FOR CALCULATION OF MCV, MCH, MCHC • Mean Corpuscular Volume (fl) • 78 – 98 (fl) • Mean Corpuscular Hemoglobin (pg) • 27 – 33 pg. • Mean corpuscular Hb concentration • 30 – 35%
CLINICAL EXAMPLE • A patient came with a history of fatigue, weakness. His blood analysis was done RBC count 3.6 × 106 / mm3 Hb concentration 7.0 g / 100ml PCV 25% MCV 69.4 fL [femtoliter] Normal 90 fL MCH 19.4 pg [picogram] Normal 30 pg MCHC 28 g / dl Normal 34 g/dl • What is Diagnosis ? • Microcytic Hypochromic Anemia [Iron deficiency Anemia]
POLYCYTHEMIA • Polycythemia is characterized by increased number of RBC and increased Hematocrit. Types of Polycythemia 1. Primary Polycythemia 2. Secondary Polycythemia
Primary Polycythemia • Primary Polycythemia is tumor like condition of bone marrow, where, there is increased production of RBC. • RBC count may reach 11 million/mm3 (normal is 5 million cells/mm3) . • Hematocrit may be 70-80% [normal 42-45%].
Primary Polycythemia • Side Effects - As there is increased viscosity of blood, it causes blood to flow very slowly, which may reduce O2 delivery to tissues. - Increased viscosity causes increased peripheral resistance which may cause increased blood pressure.
Secondary Polycythemia • Secondary Polycythemia is due to decreased O2 delivery to the tissues. • It occurs in people living at high altitude as O2 available in the air is less. • It occurs in people with chronic lung disease called Cardiac [heart] failure due to decreased O2 delivery to the tissues. • RBC count may be 6 to 8 million/mm3.
Relative Polycythemia • Relative Polycythemia occurs when there is body fluid loss e.g. diarrhea, heavy sweating. • There is body fluid loss, but no loss of erythrocytes. • This is not true Polycythemia as RBC are not increased, but only plasma volume is decreased. • As RBC are concentrated in small plasma volume, this condition is called Relative Polycythemia.
APPLIED Effect of Anemia • In Anemia, blood viscosity is decreased to 1.5 times of water [normal viscosity 2.5 – 3 times of water]. • Therefore, there is decreased peripheral resistance, it causes increased blood flow and increased venous return to heart, therefore, increased cardiac output increase heart rate. • Anemia causes hypoxia [decrease O2 delivery to tissues], therefore, increased cardiac output.
APPLIED Effect of Polycythemia • In Polycythemia, there is increased viscosity, therefore, blood flow is sluggish [slow]. • Increased viscosity leads to increased peripheral resistance, therefore, increased blood pressure can occur [in 1/3rd of polycythemic people].