ANEMIA DEFINITION & CLASSIFICATION

Maj Gen (R) Masood Anwar Professor of Haematology

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Functions of blood ◦ ◦ ◦ ◦

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Transport of nutrients Transport of gases Haemostasis Defence

Composition of blood ◦ Cells (RBC, WBC, Platelets) ◦ Plasma (Colloids, Crystalloids, Water)

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PYSIOLOGICAL DEFINITION ◦ Decrease in oxygen carrying capacity of blood.

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ANALYTICAL (PATHOLOGICAL) DEFINITION ◦ Reduction in total circulating red cell mass ◦ Reduction in Haemoglobin concentration and/or Haematocrit

These are blood cells produced in the bone marrow from a pleuripotent haemopoietic stem cell by processes of division, differentiation and maturation and released in the circulation to function mainly to transport oxygen from lungs to other tissues of the body.

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Haemoglobin (Hb) Haematocrit (Hct) [Packed Cell Volume (PCV)] Total Red Blood Cell Count (TRBC) Mean Cell Volume (MCV) Mean Cell Haemoglobin (MCH) Mean Cell Haemoglobin Concentration (MCHC) Red Cell Distribution Width (RDW)

PARAMETER

ADULT MALE

ADULT FEMALE

Hb

13-17 g/dl

12-16 g/dl

TRBC

4.5-6.5 X 1012/l

4.2-6.0 X 1012/l

Hct/PCV

40-54%/0.40-0.54 l/l

36-49%/0.36-0.49 l/l

MCV

76-96 fl

MCH

27-32 pg

MCHC

31.5-34.5 g/dl

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MORPHOLOGICAL CLASSIFICATION Based on appearance of RBC under the microscope OR red blood cell indices

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PATHOLOGICAL CLASSIFICATION Based on abnormality of anatomical, biochemical or physiological abnormality

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ETIOLOGICAL CLASSIFICATION Based on specific causative process/agent

Normocytic normochromic anaemia

Hypochromic Microcytic Anaemia

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Iron deficiency anaemia Thalassaemia minor Sideroblastic anaemia Anaemia of chronic disorders

Macrocytic anaemia

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Megaloblastic anaemia Aplastic anaemia Myxoedema Chronic Obstructive Pulmonary Disease Liver Disease Myelodysplastic syndromes

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Blood loss ◦ Acute ◦ Chronic

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Decreased production ◦ Disturbance of proliferation and differentiation  Of stem cells  Of erythroblasts

◦ Defective Hb synthesis 

Increased destruction ◦ Intracarpuscular (Intrinsic) defects ◦ Extracarpuscular (Extrinsic) defects

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Hereditary ◦ Blood loss – Hereditary Intestinal telengiectasia ◦ Decreased production – Pure Red Cell aplasia ◦ Increased destruction – Membrane, Enzyme and Hb defects

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Congenital ◦ Defective production – Congenital dyserythropoietic anaemia,Congenital sideroblastic anaemia ◦ Increased destruction – Cardiac defects, vascular defects

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Acquired

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Blood loss ◦ Acute ◦ Chronic  Ulcerative lesions of GIT  Female reproductive system  Parasites – Ankylostoma duodenale, Schistosoma haematobium

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Increased destruction of RBC ◦ ◦ ◦ ◦

Membrane defect (PNH) Mechanical trauma (Microangiopathies) Antibody mediated (Immune haemolytic anaemia) Parasites (malaria, Aroya fever)

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Decreased production ◦ Deficiency anaemias  Iron deficiency  Vitamin B12 and Folate deficiency

◦ Bone marrow disease/infiltration ◦ Miscellaneous  Pyridoxin responsive anaemia  Sideroblastic anaemia