Pernicious Anaemia

Question 1

What is pernicious anaemia?

Answer 1

It is defined as an autoimmune condition in which there is antibody formation against gastric parietal cells ± intrinsic factor – resulting in reduced vitamin B12 absorption

Question 2

What is the most common cause of vitamin B12 deficiency?

Answer 2

Pernicous Anaemia

Question 3

Describe the physiological process of intestinal vitamin B12 absorption

Answer 3

It is dependent upon intrinsic factor, which is a protein produced by gastric parietal cells

There is binding between vitamin B12 and intrinsic factor, resulting in the formation of the IF-B12 complex, which can then be absorbed by the distal ileum

Question 4

What are the two functions of vitamin B12?

Answer 4

Red blood cell production

Myelination of nerves

Question 5

Describe the pathophysiology of pernicous anaemia

Answer 5

There is antibody formation resulting in reduced intrinsic factor binding sites or reduced intrinsic factor production, ultimately leading to reduced vitamin B12 absorption

This results in the development of megaloblastic anaemia and neuropathy

Question 6

What four risk factors are associated with pernicous anaemia?

Answer 6

Middle Aged

Female Gender

Autoimmune Disorders

Blood Group

Question 7

What are the eleven clinical features of pernicous anaemia?

Answer 7

Fatigue

Pallor

Dizziness

Dyspnoea

Palpitations

Jaundice

Glossitis

Paraesthesia

Muscle Weakness

Poor Concentration

Memory Loss

Question 8

In pernicious anaemia, individuals present with a lemon tinge to their skin. Explain

Answer 8

This is due to the combination of mild jaundice and pallor

Question 9

What is glossitis?

Answer 9

It is defined as an inflammed, sore and smooth tongue

Question 10

What two investigations are used to diagnose pernicous anaemia?

Answer 10

Blood Tests

Blood Film

Question 11

What seven blood test results indicate pernicous anaemia?

Answer 11

Decreased Haemoglobin Levels

Increased MCV > 100

Decreased WBC Levels

Decreased Platelet Levels

Decreased Vitamin B12 Levels < 200

Positive Anti-Intrinsic Factor Antibodies

Positive Anti-Gastric Parietal Cell Antibodies

Question 12

Which is the gold standard antibody test used to diagnose pernicous anaemia?

Answer 12

Anti-Intrinsic Factor Antibodies

Question 13

What are the two features of pernicous anaemia on blood film?

Answer 13

Hypersegmented Polymorphs

Oval Macrocytes

Question 14

What are the two pharmacological management options of pernicous anaemia?

Answer 14

Vitamin B12 Replacement

Folic Acid Supplementation

Question 15

What is the gold standard management option of pernicious anaemia?

Answer 15

Vitamin B12 Replacement

Question 16

Describe the vitamin B12 replacement treatment course used to manage pernicous anaemia - in the absence of neurological features

Answer 16

It involves administration of three intramuscular 1mg hydroxocobalamin injections per week for 2 weeks, followed by administration every 3 months

Question 17

Describe the vitamin B12 replacement treatment course used to manage pernicous anaemia - when there is development of neurological features

Answer 17

It involves administration of intramuscular 1mg hydroxocobalamin injections every other day until features are resolved

Question 18

When are folic acid supplements used to manage pernicous anaemia?

Answer 18

When there is development of folate deficiency

Question 19

When there is development of both vitamin B12 and folate deficiency, which should be corrected first? Explain

Answer 19

Vitamin B12 deficiency

In order to prevent subacute combined degeneration of the spinal cord

Question 20

What are the four complications associated with pernicious anaemia?

Answer 20

Peripheral Neuropathy

Subacute Combined Spinal Cord Degeneration

Neuropsychiatric Disorder

Gastric Cancer