Ageing 8: Immunity & Infections Flashcards
(11 cards)
True or false: aging is relatively linear
- False
- The body has many redundancies; over time, individual failures compound into global dysfunction
What is immunosenescence? What pathologies can arise as a consequence of it?
- Progressive loss of immune function with age
- Assoc with autoimmunity, infection, and malignancy
What are some biological factors that occur during immunosenescence? Which arm of the immune system is more vs less impaired?
- Reduced haematopoiesis in general
- Shift from naive -> memory cells (harder to respond to new infections; worse response to vaccines)
- Reduced function of macrophages/neutrophils
- DC antigen uptake impaired
Adaptive (fancy) immune system is more impaired than innate (good old fashioned)
What is inflammaging? What phenotype causes it? How can this contribute to immunosenescence?
- Persistent increase in production of pro-inflam mediators
- Caused by senescence associated secretory phenotype
- Baseline increase in inflam contributes to immunosenescence
How does immunosenescence immune response?
- Slower to produce local inflam response/stop overactive inflam repsonse
- Slower to develop sepsis
- No robust vaccine/Ab response
What are common infections in older people, and the corresponding system changes that ↑ occurrence?
- Resp (pneumonia, flu): reduced mucociliary clearance, diminished cough reflex)
- Urinary: incontinence/incomplete emptying
- Skin/soft tissue: thinning and loss of subcut tissue (+/- T2DM)
- CNS: weakened microglial response to disturbance
Which infections from the slide did the ID consultant tell to remember regarding ↑ incidence in elderly?
- Pneumonia
- Bacteraemia
- UTI
- Infective endocarditis
How does infection present differently in older people?
- Won’t always can fever (can even cause hypothermia; how?)
- WCC count may be low
- CRP may be slower to rise
- Non-localising signs may predominate (like confusion [why?] or wealness/falls)
Infection reduction measures in older people
- Stop causes: good skin care, continence mgmt, bowel care (incl limiting diverticular disease)
- Ensure adequate nutrient intake
- Hand hygiene at all times
- Vaccines
High yield septic screen for Geri’s
- CXR
- Blood/urine culture
Older people don’t produce as strong immune/Ab responses to vaccines. How does this affect: formulation, schedule, and timing
- Formulation: high-dose/adjuvanted vaccines
- Schedule: multiple (rather than single doses) e.g. shingrix (why this one in particular)
- Frequency: increase frequency/boosters
