Nada Mohamed Ahmed ,MD, MT (ASCP)i

Introduction to anemia

contents

Introduction to RBC’s RBC cell indices and Haemeglobin Anemia- Definitionclassification of AnemiaSigns and symptoms of AnemiaDiagnosis

Introduction To RBC

The mature erythrocytes are non-nucleated cells and lack usual cell organelles.

The normal RBC is biconcave in shape,7.2µm in diameter and has a thickness of 2.4µm at the periphery and 1µm in the center.

The biconcave shape helps the RBC to pass through the smallest capillaries

90% of the RBC’s weight is concentrated in the red pigment hemoglobin and the RBC’s have a lifespan of 120±30 days.

Functions of RBC

• The most important function of an RBC

1- is the transportation of oxygen to tissues.

2- Another important function of RBC’s is the transportation of CO2

from the tissues to the lungs.

Normal Values

• Range of normal RBC count is:5.5±1.0 in Men and 4.8±1.0 ×1012/L in women

• Hemoglobin content being 15.5±2.5(13-18)g/dl in Men and 14.0±2.5(11.5-16.5)g/dl and Women.

• The packed cell volume (PCV) or the haematocrit is the volume of the erythrocytes per litre of whole blood is 40-54% in Men and 37-47% in Women

• Based on these normal values red cell indices have been calculated ,which are of diagnostic importance.

Haemoglobin

• Haemoglobin is a basic protein,GLOBIN and of iron-porphyrin complex HEME with a molecular weight of 68,000 dalton and consists of 4 polypeptides.

RBC Destruction and Recycling

History of Anemia

• The word "anemia" is composed of two Greek roots that together mean "without blood,“

• The ancients readily recognized the importance of blood as a life- giving substance, believing it to hold the body's vital force

Definition of Anemia :

Low Hb level less than normal range Less than 13.5 g/dl Adult male Less than 11.5 g/dl adult female Less than 15 g/dl neonate

Other definitions RBCs count less than normal range according to age group

Decreased in hematocrit level (Packed cell volume pcv) less than normal rang

Red cell indices

• MCV (mean corpuscular volume) – The average volume of RBC NR= 80-96 fl

= Hct 10 (fl) RBC count (m/µL)

e.g. Hct= 40%RBC=5.0 (m /µL)

MCV= 40/5.0 10 = 80 fl

• MCH (mean corpuscular hemoglobin)

– The average content of Hb in average RBC. – It is directly proportional to the amount of Hb

and RBC size.

Hb

RBC count (m/µL) 10 (pg)MCH =

e.g. Hb = 14 g/dlRBC = 4.8 (m/µL)

MCH= 14/4 10 = 29 pg

NR= 27-32 pg

• MCHC (mean corpuscular hemoglobin concentration)

• NR= 32-36%

– Express the average concentration of hemoglobin per unit volume of RBC.

– It defined as the ratio of the weight of hemoglobin to volume of RBC.

Hb (g/dl)

Hct (%)

100 (%)MCHC=

e.g. Hb = 14 g/dlHct = 45 %

MCHC 14/45 100 = 31%

Classification of Anemia

I. Etiologic Classification 1. Impaired RBC production 2. Excessive destruction 3. Blood loss

II. Morphologic Classification 1. Macrocytic anemia 2. Microcytic hypochromic

anemia 3. Normochromic normocytic

anemia

Impaired RBC Production

1. Abnormal bone marrow (Aplastic anemia)

2. Essential factors deficiency

3.Anemia in renal disease : Erythropoietin

Excessive Destruction of RBC(cont.)

Hemolytic anemia 1. Intracorpuscular defect(defect inside

the cell)

1.1 Membrane : Hereditary spherocytosis

Hereditary ovalocytosis, etc.

1.2 Enzyme : G-6PD deficiency, PK def., 1.3 Hemoglobin : Thalassemia,sickle

cell anemia

Excessive Destruction of RBC

2. Extracorpuscular defect1. Mechanical trauma : 2. Infection : Clostridium tetani,

malaria parasites.3.Antibodies : HTR (Hemolytic

transfusion reaction) , SLE(Systemic lupus erythematosus)

Blood Loss

1. Acute blood loss : Accident, GIbleeding2. Chronic blood loss : Hypermenorrhea

Macrocytic Anemia MCV > 94 fl

Megaloblastic anemia

1 . Vit. B12 deficiency2. Folic acid deficiency : Nutritional

megaloblastic anemia.

Microcytic Hypochromic Anemia MCV < 80 fl

1. Iron deficiency anemia 2. Thalassemia 3. Sidroblastic anemia 4. Anemia due to lead

poisoning.

Normocytic Normochromic Anemia

MCV 82 – 92 fl • 1. Blood loss• 2. Increased plasma volume : Pregnancy, • 3. Hemolytic anemia : depend on each cause• 5. Infiltrate BM : Leukemia, Multiple myeloma, Myelofibrosis, etc.• 6. Abnormal endocrine : Hypothyroidism, Adrenal • insufficiency, etc.• 7. Kidney disease / Liver disease / Cirrhosis

Signs and Symptoms

Diagnosis Haemoglobin EstimationPeripheral blood smear

examinationRed cell indicesReticulocyte countErythrocyte sedimentation

rate ESRSpecial test for special

type of AnemiaBone marrow examination