Immunology

Question 1

The immune system is commonly divided into innate and adaptive immunity. Which one of the following is correct?

• CD4+ve helper T cells are the central hub of the innate immune system
• Macrophages cannot attack microbes without first undergoing clonal expansion of the right clone fitting a specific microbe
• Deficiency in innate immunity wouldn’t be expected to cause clinical problems as long as adaptive immunity remains intact
• NK cells are part of the innate immune system because they don’t require prior learning to know which cells to kill
• Innate immunity is a key feature required for vaccination

Answer 1

NK cells are part of the innate immune system because they don’t require prior learning to know which cells to kill

Question 2

Which of the following correctly describes vaccination?

• The 6-in-1 vaccine (given at 2 months, 3 months and 4 months) is primarily done because it contains several different antigens
• If you’ve had the MMR vaccination within the last 4 weeks you should stay away from pregnant women or babies
• 20 year old male student is in doubt as to whether he had all the required MMR vaccinations. Finding his immunisation records is critical because an extra MMR injection would be risky
• Vaccination of HIV patients produces the same results as in healthy patients because only T helper cells but not B lymphocytes are reduced in HIV
• The formation of memory B cells accounts for the rapid production of IgG at re-exposure to a microbe after vaccination

Answer 2

The formation of memory B cells accounts for the rapid production of IgG at re-exposure to a microbe after vaccination

Question 3

Which one of the following is correct?

• biologics are not metabolised by the liver but instead eliminated via renal excretion
• targeted biologics such as anti-TNF (adalimumab) are functionally equivalent to passive immunisation
• common drugs used to suppress autoimmune conditions e.g. methotrexate, ciclosporine and systemic steroids have very similar side effect profiles
• biologics targeting specific cytokines are commonly more immunosuppressive than glucocorticoids
• immunoglobulins can be administered in immunodeficiency, such as CVID or leukaemia, but not in autoimmune conditions such as pemphigus, dermatomyositis or Myasthenia gravis

Answer 3

biologics are not metabolised by the liver but instead eliminated via renal excretion - key point, biologics are safe in patients with liver disease

Question 4

Answer 4

1. TTG Iga is for Coeliac, anti-CCP and anti-dsDNA are for rheumatoid, anti-ACh is for myasthenia gravis. C is correct
2. Parietal cell antibody is for PA, anti-CCP is for rheumatoid, anti-Jo-1 is for dermatomyositis/polymyositis, anti-Ro is for Sjogren’s and anti-Scl-70 is for systemic sclerosis
3. Correct answer is D, NB - methotrexate is NOT immunosuppressive, it is anti-inflammatory

Question 5

Answer 5

4. D is correct, suspected Myasthenia gravis? Treatment is anticholinesterase inhibitors (neostigmine) and long term steroids
5. The incorrect option is E, CVID most commonly features low IgG and both CVID and selective IgA deficiency are very common

Question 6

Answer 6

6a. E, methotrexate should be avoided in liver disease
6b. 1, 2 and 4 are all correct, but 3 is describing a biologic which is safe to use in the context of liver disease