Course title : Hematology (1) Course code : MLHE- 201 Supervisor: Prof. Dr Magda Sultan Date :10/10/2013

Outcome : The student will know : The importance of Hemoglobin. The importance of Hematocrit. How to calculate the red cell indices?

Red Blood Cells Haemoglobin concentration If red cells are lysed, the haemoglobin is released from the red cells and forms a solution in the plasma. The haemoglobin concentration (Hb) can be measured biochemically by light absorption at a specified wave length after a chemical reaction which converts haemoglobin to cyanmethaemoglobin.

Hb is measured in either grams per decilitre (g/dl) or grams per litre (g/l). A fall in the Hb is referred to as anaemia.

Haematocrit or packed cell volume An alternative way of detecting anaemia is to centrifuge a tube containing an aliquot of blood and measure the proportion of the column of blood which is occupied by the red cells. This test is called a packed cell volume (PCV) or a haematocrit (Hct). This measurement is expressed as a decimal percentage, i.e. as litres/litre (e.g. 0.45).

Red cell indices Red cells can vary in their size and in the amount of haemoglobin contained in an individual cell. Diagnostically useful informations can be obtained by measuring the red cell indices : Mean cell volume (MCV). Mean cell haemoglobin (MCH). Mean cell haemoglobin concentration (MCHC).

The formulae which relate the various red cell indices to each other are as follows: MCV is measured in femtolitres MCH is measured in picograms MCHC is measured in g/dl

Normal ranges In order to interpret blood counts it is necessary to know what is normal. This is usually done by reference to either a normal or a reference range.

Assessing Red Cells Red cells should be assessed as to their: number size shape degree of haemoglobinization distribution in the blood film.

Assessing red cell number and distribution -Anaemia -Polycythaemia - Rouleaux formation - Red cell agglutination

Normal distribution of red cells in a healthy subject with normal Hb.

Anaemia (caused by iron deficiency)

Polycythaemia.

Rouleaux

Red cell agglutinates

Assessing red cell size: -Microcytosis. -Macrocytosis. -Anisocytosis. If cells are smaller than normal they are described as microcytic and if larger than normal as macrocytic. Red cells of normal size are said to be normocytic. If red cells show greater variation in size than normal the blood film is said to show anisocytosis.

Normocytic red cells.

Microcytic red cells (MCV 62fl )

Macrocytic red cells (MCV 105 fl)

Anisocytosis

Assessing red cell shape (poikilocytosis) If red cells show more than the normal degree of variation in red cell shape there is said to be poikilocytosis

Diagrammatic representation of different types of poikilocyte

Moderate numbers of spherocytes (in hereditary spherocytosis

Several irregularly contracted cells (in haemoglobin C disease). The majority of the other cells are target cells.

Numerous elliptocytes and ovalocytes (in hereditary elliptocytosis).

Several dacrocytes (tear-drop poikilocytes) (in idiopathic myelofibrosis).

Numerous stomatocytes (in hereditary stomatocytosis).

Several keratocytes (in microangiopathic haemolytic anaemia); keratocytes are sometimes called ‘bite cells’ because they look as if a bite has been taken from them

Several schistocytes (red cell fragments) including a microspherocyte (in haemolytic uraemic syndrom e)

Echinocytes (crenated cells) (in chronic renal failure)

Acanthocytes (in abetalipoproteinaemia

One sickle cell and several boat-shaped cells (in sickle cell anaemia )

Assessing red cell colour: - Normochromic - Hypochromic

Normochromic red cells

Hypochromic red cells

Assignment Students namesAssignment الشيماء مصطفي عبد العاطي امل محمد احمد اميره اسعد يوسف اميره صلاح مرشدي انجي عبد الموجود اوركيد اشرف ايمان سعيد محمد ايمان محمدي يوسف ايه رجب عبد العزيز ايه حماده عطيه Counting chamber in cell counts. ابانوب عوض ناجي باخوم سدراك نظير باسم خالد محمد بسمه مهدي رياض بسنت اشرف محمد بسنت حسن علي تغريد محمود ابراهيم حسام الدين حسين حسام حسين منصور حماده محمد عشري Red cell assessment.

Training Questions : What are the red cell indices formulae ? Mention the different red cell shapes. How to assess red cells regarding their size ?

Reference book - Dacie - Essential Haematology