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Flashcards in Ageing and Immunity Deck (25)
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1

Which infections are more common in the elderly?

  • Sepsis 
  • Pneumonia 
  • Asymptomatic bacteruria -> UTIs
  • Influenza
  • Herpes zoster -> post-herpetic neuralgia 

2

What are key features of the innate immune system?

  • Rapid responses
  • Physical barriers - muscosal membranes + skin
  • Unchanged w/ repeated exposure
  • Phagocytosis main cellular process

3

What are key features of the adaptive immune system?

  • Specific reactive response
  • Memory for recurrent exposure
  • Lymphocytes - T + B
  • Speel + thymus important organs

4

Which cells are involved in innate immunity and which one of these is the main antigen-presenting cell?

  • Mast cell
  • Dendritic cell
  • Macrophage
  • Neutrophil
  • Eosinophil
  • Basophil
  • Complement protein
  • Natural killer cell

5

What is the role of the dendritic cell?

Dendritic cell performs some phagocytosis but presents new antigens to T cells - this is where adaptive immunity is initiated. 

6

What happens to neutrophils during ageing?

  • Less recruitment to site of infection 
  • Less phagocytosis
  • Less signalling
  • Less intracellular killing

7

What happens to dendritic cells during ageing?

  • Less phagocytosis
  • Less migration
  • Reduced antigen capture + presentation 

8

What happens to macrophages during ageing?

  • Reduced recruitment to site of infection
  • Causes more collateral damage (to healthy cells as well)
  • Reduced phagocytosis + killing ability

9

What changes occur in B-cells in regards to ageing?

  • More non-specific antibodies produced
  • More antibodies against self-antigens (autoimmune)
  • Lower affinity + diversity of antibodies 

10

Immunosenescence refers to the gradual deterioration of the immune system brought on by natural age advancement. Describe T-cell immunosenescence

  • Thymic involution 
  • Reduction in naive T cells 
  • Less of new T cells, but more of old T cells 
  • Inability to respond to novel antigens 
  • Less T helper support of B cell population

11

Many cells produce cytokines, both pro and anti-inflammatory. Ageing is accompanied by an increase in which type? What are examples?

Ageing accompanied by increased pro-inflammatory cytokines - mainly IL-6, TNF-alpha

12

What does increased background inflammation (inflammaging) do?

  • Reduces response to specific infective stressors
  • Exacerbates conditions w inflammatory aetiology
    -> autoimmune disease
    -> alzheimer's
    -> cardiovascular disease

13

Elderly patients often don't come to hospital presenting with typical infectious symptoms, so what do they come in with?

  • Delirium
  • Lethargy
  • Falls 
  • Anorexia

Can be caused by anything

14

What is difficult about diagnosing elderly patients coming into hospital?

  • 50% present later due to blunted inflammatory response
  • Cognitive impairment makes history more difficult
  • Imaging + microbiology specimens are difficult to obtain

15

Multiple admissions mean increased drug resistant organisms, such as?

  • MRSA
  • ESBL 

16

Which healthcare associated infections are more common in elderly patients?

  • Catheter Associated UTI
  • Hospital acquired pneumonia
  • C. diff

17

Co-morbidity increases likelihood of organ specific septic complications, such as?

  • Acute kidney injury
  • Cardiac dysfunction + type 2 MI

18

What do we see in regards to vaccination in elderly people?

  • Vaccine response is attenuated (reduced) by immune senescence
  • Response rate 30-40% in over 65s, 80% in under 65s

19

What is the impact of influenza vaccination?

  • Benefit to older people due to high incidence + mortality
  • Reduction in mortality, morbidity + hospitalisation 

20

What other vaccination is often co-administered with the influenza vaccine?

  • Pneumococcal vaccination
  • Moderate efficacy in older people
  • Cost-effective due to low cost of co-administration with flu vaccine

21

There are slight increase in autoimmune disease in the elderly. Specifically which autoantibody is more frequent?

Increased rheumatoid factor -> RA!

 

22

What is the median age of cancer diagnosis?

  • 70
  • Cancer incidence increases with age

23

In which individuals is there an increased frequency of cancer?

  • Immunosupressed individuals:
  • HIV
  • Solid organ transplants
  • Long term immunosupression for autoimmune conditions

24

What is immunosurveillance?

  • If a normal cell is faulty/abnormally functioning, it will kill itself by apoptosis
  • Cancer is the upregulation of abnormal endogenous cells
  • Precursor cells of cancer in whom apoptosis has not occurred should be destroyed by a healthy immune system
  • So immunosurveillance is a important role of the immune system

25

How does immune senescence (T cells) contribute to an increased likelihood of cancer?

  • Particularly T cells reduced identification of abnormal cells
  • Decreased cytotoxic activity
  • Allows tumour cells to escape immunosurveillance + subsequent destruction