12. Immune Health Flashcards
(109 cards)
What is the immune system?
- The immune system is a sophisticated system of surveillance, that can identify and neutralise potential threats, and repair resulting damage. It also identifies and neutralises damaged ‘self’ cells e.g., cancer.
- It needs to be effective, proportionate and precise — too little and it may compromise health / survival, too much or poorly targeted, may result in chronic inflammation, allergy or autoimmunity.
Role of the IS and associated dysfunctions? x5
- Identify and neutralise pathogens ==> increased risk of infections
- distinguish self vs. non-self antigens ==> increased risk of autoimmunity
- distinguish pathological vs non-harmful antigens ==> allergies and autoimmunity (cross-reactivity)
- Repair the site of any injury or damage ==> insufficient (incomplete repair, scarring) Excessive (cell damage, chromic inflammation)
- Tumour surveillance ==> inability to effectively recognise and kill abnormal cancer cells
Immune over reaction to internal and external threat
Internal threat:
Autoimmune condition (e.g., Hashimoto’s thyroiditis, rheumatoid arthritis, IBD, Type 1 diabetes etc.).
External threat:
1. Allergic reactions (e.g., food allergies, hay fever).
2. Food intolerances.
Immune under reaction to internal and external threat
Internal threat:
1. Cancer.
2. Re-activated viruses (e.g., shingles).
External threat:
Infection (e.g., bacterial, parasite, viral, fungal.)
What is the Terrain Theory?
Terrain theory helps explain why some people become unwell and others don’t despite the same pathogen exposure.
1. Pathogens may become harmful in a certain context, depending on the overall health and resilience, immune function, stress levels, emotional state, gut function, microbiome etc.
2. Health (esp. GI) is a key factor in resilience against infection and taking a natural approach is essential for immune support.
What are the New Immune Challenges of modern times? x4
- Dysfunctional immune programming due to less diverse early pathogen exposure, compromised gut / microbiome.
- New antigens — increased consumption of allergenic foods, exposure to toxins (e.g., mould).
- Reduced resilience due to unhealthy lifestyles e.g., metabolic dysfunction, oxidative stress.
- Overuse of antibiotics leading to antibiotic-resistant infections.
Resulting in potentially suboptimal immune response to infection… yet with higher levels of inflammation, autoimmunity and allergy.
What is effective immunity dependent on?
- Healthy barrier tissue integrity, where pathogens make first contact — skin, gut, lungs etc.
- Presence of secretions — tears, saliva etc., which have antimicrobial properties. Healthy mucus production is an essential barrier.
- Probiotic bacteria occupy space on epithelial surfaces, secreting lactic acid and natural antibiotics.
- Immune activity is concentrated at key points of entry — MALT / GALT (e.g., tonsils, Peyer’s patches), containing large numbers of immune cells including B cells, secreting sIgA.
- Healthy innate immune response involves mobilisation of leukocytes such as macrophages, dendritic cells, neutrophils, mast cells etc. They survey and recognise pathogens via pattern recognition (PAMPs, DAMPs) and neutralise them via phagocytosis, production of reactive oxygen species, lactoferrin etc. * Inflammation — ‘quarantines’ a specific area and ↑ immune activity. (See ‘Chronic Inflammation’).
- Many innate immune cells then act as antigen presenting cells (APCs) to the adaptive immune system, which can support with a more tailored response to a specific threat.
PAMPs / DAMPs = pathogen / damage associated molecular patterns
What are t-helper cells?
After antigen presentation naïve T-helper cells can differentiate into either Th1, Th2, Th17 or T-reg cells.
What is the function of Th1 cells vs. Th2 cells and Th17 vs T-reg cells.?
Th1 cells: Defence against intracellular pathogens (e.g., viruses). Anti-cancer / tumour.
Th2 cells: Defence against extracellular threats (e.g., parasites).
Th17 cells: Defence against extracellular pathogens.
T-reg cells: Modulate and deactivate the immune response. The majority of peripherally produced T-reg cells originate in the GALT.
What happen in Th1 or Th2 dominance?
Th1 dominance drives chronic inflammation and autoimmunity.
Th2 dominance drives allergies (incl. asthma / the atopic triad).
What is crosstalk between Th1 and Th2?
Crosstalk — when Th1 is activated, IL-12 and IFN-γ downregulate Th2, and when Th2 is activated IL-4 downregulates Th1.
What are the clinical indications of low immunity?
History of increased susceptibility to, severity of, or prolonged infections, e.g., respiratory, urogenital, skin etc.
Fatigue, loss of appetite, weight loss, fevers, chills, aches and pains, enlarged lymph nodes. Specific symptoms, depending on site of infection — soreness / pain, coughing, runny nose, phlegm.
How to test low immunity?
Low WBC count (blood)
Low sIgA (stool or saliva test).
Positive test for pathogen or antibodies — e.g., blood antigen test for hepatitis and EBV antibodies, urine testing for STDs, stool testing for gut pathogens, other microbiome testing (e.g., vaginal).
Causes and risk factors for low immunity - the hygiene hypothesis
‘Hygiene hypothesis’ — pathogen exposure is needed for the neonatal immune system to develop.
- Inadequate antigen exposure is associated with increased atopic diseases and autoimmunity.
- Neonates are born with a TH2 immune bias, and exposure to pathogens increases TH1, achieving immune learning and balance, in parallel with acquisition of gut microflora. Lack of exposure is linked to increased atopic allergy.
- Additionally, breast feeding (GOS, other prebiotics, colostrum, growth factors, maternal immune cells) enhance the maturation of immunity and the microflora.
GOS = galacto- oligosaccharides
Other causes and risk factors of low immunity? x11
- Poor nutrition (e.g., high refined sugars, alcohol) / nutrient deficiencies, especially zinc and vitamin A, D and C.
- Immunosuppressants e.g., corticosteroids, methotrexate, azathioprine.
- Gut / microbiome — commensals offer direct immune protection and programme a healthy immune response. Compromised with c-section, formula-fed, antibiotics, overly hygienic upbringing, dysbiosis / low sIgA, PPIs, NSAIDs, steroids.
- Impaired barrier defences — poor skin quality (e.g., topical steroids / irritants, nutrient deficiencies such as zinc and EFAs), damaged lungs (e.g., smoking, pollutants), gut permeability, tonsillectomy, adenoidectomy, appendectomy.
- Emotional (incl. fear), chemical (e.g., smoking) and physical stress (e.g., overtraining) – ↑ cortisol inhibits phagocytes, NK cells and lymphocyte activity.
- Poor sleep — ↓ immune memory, ↓ anti-viral cytokines (IL-12 / IFN- γ), ↑ inflammatory cytokines (e.g., IL-6), ↓ lymphocyte blastogenesis.
- Heavy metal toxicity can inhibit lymphocyte proliferation.
- Blood glucose dysregulation (consider diet / stress etc.) — hyperglycaemia activates protein kinase C (PKC) which inhibits phagocytosis and superoxide production, significantly altering the innate immune response.
Blood glucose spikes (hyper- ==> hypoglycaemia = ↑ cortisol = gluconeogenesis and so on…). - Poor energy delivery mechanisms (e.g., CFS — see stress / fatigue).
- Disrupted methylation (e.g., due to nutrient deficiencies, SNPs) impairs leukocyte differentiation and maturation. The folate cycle is important for DNA synthesis and repair (requiring folate, B2 and B3).
PKC = An enzyme that is involved in controlling the function of other proteins - Low vitamin D status, e.g., due to:
* Inadequate UVB sun exposure, dietary intake, absorption etc.
* Genetic polymorphisms / SNPs.
How to naturally support immune functions ?
- Get the basics right — CNM Naturopathic Diet. Optimise the terrain.
- Reduce / eliminate sugar, alcohol, caffeine. Keep a healthy weight.
- Regular activity (avoid under and over-exercising), especially outdoors. Fresh woodland or sea air (phytoncides, mineral content) are especially beneficial.
- Support sleep, reduce stress, toxic exposure. Listen to the body when fighting infection and get bed rest to conserve energy.
- Digestion / GI health is vital — promoting a healthy microbiome with a high prebiotic diet; chewing well; time to digest when relaxed.
Nutrients for supporting the IS - x6
- Vit A
- Vit C
- Zinc
- Probiotics
- Vit D
- Beta Glucans
Nutrients for supporting the IS - Vitamin C
Supports the innate and adaptive immune systems and epithelial barrier.
Deficiency = higher susceptibility to infections. Prevention requires adequate, if not saturating plasma levels.
Buffered form e.g., magnesium ascorbate, ester-C 1–5000 mg / day.
Nutrients for supporting the IS - Zinc
Inhibits viral replication, permeability of barriers, and ↑ specific anti-viral immune defenses. It boosts immunity in children and can reduce respiratory infection risk in the elderly.
Chelated form e.g., zinc citrate, gluconate 10–15 mg / day.
Nutrients for supporting the IS - Probiotics
Act as a ’low level’ challenge to the immune system, via action on toll-like receptors in GALT. Various probiotics boost sIgA, incl. several Lactobacilli spp. and Saccharomyces boulardii.
1–30 billion, depending on strain.
Vitamin D
Enhances the innate immune system, increases regulatory T-cells and downregulates T-cell-driven IgG production. Shifts towards Th2.
While enhancing protective innate immune responses, vitamin D helps maintain self-tolerance by dampening excessive immune responses.
Lower levels are associated with higher susceptibility, complications, and mortality. Optimal serum levels are associated with reduced risk of acute URTs.
Cholecalciferol (D3) 1000‒2000 iu / day or higher as per testing if deficient (10–20000 iu).
Nutrients for supporting the IS - Beta Glucan
1,3 and 1,6 support innate and adaptive immunity and are particularly supportive against upper respiratory tract infections. They exert immune-modulating and anti-tumour effects.
900mg
Nutrients for supporting the IS - Vitamin A
Supports lymphatic tissues and immune cells, maintains lung barrier function. Deficiency associated with severe respiratory tract infections, including pneumonia.
Retinol acetate / palmitate Dose: 2500–5000 iu / day.
Medicinal mushrooms for low immunity - how they work?
Medicinal mushrooms — contain polysaccharides including beta-glucans which interact with receptors in GALT — Dectin-1 and TLR2 and 6, boosting sIgA and TH1 immunity. In addition they have a prebiotic effect.