Anemia & Thalassemia Flashcards

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1
Q

What is the definition of Anemia?

A

A decrease in Hb concentrations in the blood, below the reference level for a person’s sex and age.

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2
Q

What are the reference levels for a male and female adult?

A
  1. 5 - 17.5 g/dL (Male adult)

11. 5 - 15.5 g/dL (Female adult)

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3
Q

What are the outcomes of anemia?

A
  • reduced O2 delivery to tissues, leading to tissue hypoxia
  • due to widespread nature of hypoxia, will affect many different systems/ organs, most notably skeletal muscle, heart and CNS (weakness - lack of stamina)
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4
Q

What groups of people are most likely to suffer from Anemia?

A

pre-menopausal women, indian women, over 65 year olds and infants

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5
Q

What is the difference between mild/ moderate anemia and severe anemia?

A

With mild/moderate anemia, symptoms occur on/after exertion whereas with severe anemia, symptoms occur and worsen at rest.

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6
Q

What are the different types of anemia?

A
  1. Normochromic normocytic anemia
    - normal MCHC, normal MCV
    - hemolytic anemias
  2. Hypochromic microcytic anemia
    - low MCHC, low MCV
    - undercoloured under sized
    - iron deficiency anemia
    - thalassemia
  3. Normochromic macrocytic anemia
    - normal MCHC, high MCV
    - vit B12 deficiency
    - oversized due to nutritional deficiencies
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7
Q

How can RBC Morphology be characterised?

A

Mean Corpuscular Volume (MCV), Mean Cell Hb (MCH) and Mean cell Hb Conc (MCHC)

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8
Q

What are the causes of Hemolytic anemias?

A
  1. Defects inside the RBC
    - sickle cell disease
    - G6PD deficiency ( the enzyme protects RBC from things that can harm them. Without them, hemolysis can occur, developing hemolytic anemia)
  2. Defects in the RBC membrane
    - RBC could get pushed out of the spleen an dlose some of the membrane and turn into a sphere- making it more brittle and fragile
  3. Defects outside of the RBC
    - auto-immune hemolytic anemia or acquired
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9
Q

What laboratory findings can be suspected to be found if a patient has iron deficiency anemia?

A
  • decreased serum ferritin <12mcg/L
  • decreased serum Iron
  • decreased MCV
  • pencil shaped cells
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10
Q

What are the 3 types of Haemoglobin found in adults?

A

HbF, HbA and HbA2

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11
Q

What are Haemoglobinopathies?

A

Inherited disorders affecting the rate of synthesis / structure of the globin chains in haemoglobin.

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12
Q

What are Thalassemias?

A

A group of Haemoglobinopathies that cause hemolytic anemia due to reduced or absent synthesis of one or more globin chain types.

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13
Q

What is the cause of alpha thalassemia?

A

Gene deletions involving HBA1 and HBA2 genes

- reduces production of haemoglobin

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14
Q

What is the sole significant phenotype for alpha thalassemia?

A

Anemia causing pale skin

- Haemoglobin H disease

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15
Q

What happens during beta thalassemia?

A

There is a reduced or absent beta globin chain synthesis. This increases alpha, delta and gamma chain synthesis to compensate resulting in poor production of functioning RBC. Cells more fragile and therefore failure to synthesise properly.

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16
Q

What is the cause of beta thalassemia?

A

Abnormality in the beta globin gene (2000 gene defects)

17
Q

What are the clinical phenotype classifications for the different types of thalassemias?

A

Homozygote genotype present causes thalassemia major (severe anemia)
Beta+/Beta+ causes thalassemia intermedia. (moderate anemia) Heterozygous seen with defect seen in only one gene is thalassemia minor which is clinically insignificant. (mild anemia)

18
Q

What happens during Sickle cell anaemia?

A

RBC’s are unable to transport O2 efficiently, sickled cells at low O2 tension.
Caused by a point mutation in the beta globin gene from Glu to Val at position 6.
- need to have homozygous to be affected

19
Q

What are isoenzymes?

A

each of two or more enzymes with identical function but different structure