Immunology of Ageing

Question 1

Trends in ageing and immunology

Answer 1

Infection more common and severe (esp pneumonia, influenza, HAI)
-atypical presentation (often present with delirium, lack of febrile response, non specific symptoms)
Cancers more frequent
AI less frequent
Inflammation increases

Question 2

Why does this happen?

Answer 2

AB decrease with age (lymphocytes fall, neutrophils increase)
Vaccine response decreases
Comorbidities increase
Malnutrition more likley

Question 3

TB in elderly

Answer 3

Primary infection in childhood => resolution with granuloma formation
May reactivate due to immune suppression/ageing
-T cells surround macrophages and neutrophils.
-No of T cells falls increasing likelihood of reactivation

Question 4

Thymic changes with age

Answer 4

As you age, your thymus is infiltrated by fat
-most active early in life and is max size by 1

Absolute no’s of T cells falls

• Naive T cells fall
• ratio between CD4:CD8 switches
• peripheral Tregs increase
• NK stays stable

Question 5

CMV

Answer 5

Persistent herpes present in most adults

• asymptomatic in immunocompetent hosts
• CMV positivity associated with premature immunosenescene (suppress T cell repetoire)

Question 6

Describe the trends in autoimmunity and autoantibodies

Answer 6

Ageing associates with more autoantibodies but a lower incidence of AI disease

Question 7

What illness increases in prevalence with age and why

Answer 7

Giant cell arteritis and polymyalgia rheumatica - IL6 mediated

Likely to be due to the natural increase in CRP and IL6 => increases atherosclerosis formation

Question 8

Why does cancer risk increase?

Answer 8

Environmental exposures
Genetic alterations (epigenetics)
Declining immune surveillance