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(1)

Anemia and

Polycythemia

(2)

Learning Objectives

At the end of the session you must be able to :

Define anaemia and describe the WHO grading of anaemia.

Describe and discuss morphological and etiological classification of anaemia

Describe the physiological effect of anaemia

Define polycythaemia and describe it’s

classification

(3)

Anemia

Definition

Anemia is defined as a decreased O2

carrying capacity of blood due to quantitative

and qualitative Reduction in RBC counts and

Hemoglobin levels.

(4)

Anemia

The name is derived from Ancient Greek:

ἀναιμία anaimia, meaning "lack of blood", from ἀν- an-, "not" and αἷμα haima, "blood“

Anaemia is labelled when Hb is less than

13 gm/dl in Males

12 gm/dl in Females

15 gm/dl in Newborn.

(5)

The hand of a person with severe anemia (on the left) compared to one without (on the

right)

(6)

WHO grading of Anemia

Population Hemoglobin level (gm/dl) Mild Moderate Severe

Women

(15 years of age

and above) 11.9 - 11 10.9 - 8 lower than 8 Men(15 years of age

and above) 12.9 - 11 10.9 - 8 Lower than 8

(7)

Classification of Anemia

Morphological Classification

Etiological Classification

(8)

Classification of Anemia

Anemia

Morphological

(based on shape and colour)

Etiological

(based on cause)

Macrocytic Anemia Microcytic hypochromic

Anemia

Normochromic normocytic

Anemia Impaired/Defective

RBC production

Excessive destruction / hemolysis

Blood loss/hemorhage

(9)

Etiological Classification

Impaired/Defective RBC production

Abnormal bone marrow

Aplastic anemia

Myelofibrosis, Leukemia,

Cancer metastasis

Essential factors deficiency

Deficiency anemia : Fe, Vit. B12, Folic acid, etc

Anemia in renal disease : Erythropoietin

(10)

Aplastic Anemias

Anemia resulting from lack of functioning bone marrow.

High-dose radiation or chemotherapy for

cancer treatment or high doses of certain toxic chemicals, can damage stem cells of the bone marrow, followed in a few weeks by anemia.

People with severe aplastic anemia usually die

unless they are treated with blood transfusions

or by bone marrow transplantation

.

(11)

Excessive destruction/ hemolysis of RBC

Different abnormalities of the RBCs, make the cells fragile, so they rupture easily as they go through the capillaries, especially through the spleen.

Even though the number of RBCs formed may be normal, or even much greater than normal, the life span of the fragile RBC is so short that the cells are destroyed faster than they can be formed, and serious anemia results

Etiological Classification

(12)

Cause of hemolysis:

Intrinsic (intracorpuscular) abnormalities:

Membrane defect : Hereditary spherocytosis Hereditary ovalocytosis, Hereditary elliptocytosis

Enzyme defect : G-6PD deficiency.

Hemoglobin defect : Thalassemia,

Sickle cell Anemia

(13)

Extrinsic (extracorpuscular) abnormalities

Antibody-mediated:

Rh disease (Erythroblastosis fetalis)

Transfusion reaction to blood transfusions

Infection:

Clostridium tetani

Malaria

Mechanical trauma to red blood cells

(14)

Blood Loss

Hemorrhage, results in a low concentration of RBCs

RBC concentration usually returns to normal within 3 to 6 weeks.

Cause:

Trauma or surgery, causing acute blood loss

Gastrointestinal tract lesions, causing either acute

bleeds (e.g. variceal lesions, peptic ulcers) or chronic blood loss

Infection by intestinal nematodes feeding on blood, such as hookworms and the roundworm

Etiological Classification

(15)

ANEMIA

morphologic classification

microcytic

MCV <80

normocytic

MCV 80-100

macrocytic

MCV >100

(16)

Morphological classification

Macrocytic Anemia

The condition of having erythrocytes which are too large, is called macrocytosis.

MCV > 100

Megaloblastic anemia

Causes: DNA replication disorders

Vit. B12 deficiency : pernicious anemia

Folic acid deficiency

inhibitors of DNA replication (poisons, drugs)

Chronic Alcoholism

(17)
(18)

William Murphy, discovered that

ingesting large amounts of liver seemed to cure the Anemia . George Minot and

George Whipple then were able to isolate

the vitamin B12 from the liver. All three

shared the 1934 Nobel Prize in Medicine.

(19)

Microcytic hypochromic Anemia

MCV < 80

characterized by small red blood cells (called microcytes).

Erythrocytes are usually hypochromic,

meaning that the red blood cells a lower- than-normal hemoglobin concentration.

therefore, anemia of this category is

described as "microcytic, hypochromic anaemia

".

Morphological classification

(20)

Causes:

Heme synthesis defect

Iron deficiency anemia (the most common form of anemia)

Anemia of chronic disease (more commonly presenting as normocytic anemia)

Globin synthesis defect

Alpha-, and beta-thalassemia

Other abnormal hemoglobins

Sideroblastic defect

Hereditary sideroblastic anemia

lead toxicity

(21)

Remember

cause of microcytic hypochromic Anemia

T- Thallasemia

A- Anemia of chronic disease

I - Iron deficiency

L – Lead poisoning

S - Sideroblastic

(22)
(23)

Normocytic Normochromic Anemia

Normocytic anemia occurs when the overall hemoglobin levels are decreased, but the red blood cell size (mean corpuscular volume)

remains normal.

MCV - 80 – 100 Cause:

Acute blood loss

Anemia of chronic disease

Hemolytic anemia

Aplastic anemia

Morphological classification

(24)

Heart Failure

(specially during exercise)

Effect of Anemia

increase in the return of blood to the heart

hypoxia causes the peripheral tissue blood vessels to dilate Blood viscosity decreases

(may fall to as low as half the normal value)

increased cardiac output, as well as increased pumping workload on the heart.

(25)

Polycythemia

Definition

It is a disease state in which the proportion of blood volume that is occupied by red blood cells increases.

An increase in the no of red blood cells =absolute polycythemia

Due to decrease in the volume of plasma

=relative polycythemia

(26)

Polycythemia

Hematocrit — Polycythemia in the adult patient is suspected when the HCT is >48 or >52 % in Females and Males , respectively.

(The hematocrit (HCT) is expressed as the percent of a blood sample occupied by intact RBCs. )

Hemoglobin concentration — when the HGB is >16.5 or >18.5 g/dL in F and M, respectively.

(27)

Polycythemia Classification

RELATIVE

Reduced plasma volume (hemoconcentration) ABSOLUTE

• Primary (Erythropoietin normal or low)  Also known as Polycythemia vera

Bone marrow cancer

• Secondary (High erythropoietin) Compensatory

Lung disease

High‐altitude living

Cyanotic heart disease Paraneoplastic

Erthropoietin secreting tumors

(28)

Primary Polycythemia

Polycythemia vera is caused by a genetic aberration in the

hemocytoblastic cells that produce the blood cells.

This causes excess production of RBCs.

the RBC count may be 7 to 8

million/mm3 and the hematocrit may be 60 to 70 percent.

Untreated, polycythemia vera can

be fatal

References

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