Immunology

1. An Introduction to Hypersensitivity

• Define hypersensitivity as an excessive, antigen-specific immune response that causes harm to the host (the person's own body).
• Differentiate between intrinsic triggers of hypersensitivity (autoimmune: aimed at the body's own molecules) and extrinsic triggers (aimed at molecules from outside the body, such as allergens [substances that trigger an allergy], drugs and infectious organisms).
• Understand how hypersensitivity develops in two phases: the sensitisation phase (the first exposure, when the immune system becomes primed to the antigen) and the later effector phase (when the primed immune system causes the damage on re-exposure).
• Identify and recall the four main hypersensitivity types (I–IV) using the ABCD mnemonic: Allergic (type I), antiBody-mediated (type II), immune Complex-mediated (type III) and Delayed (type IV).
• Classify Type I (immediate allergy), Type II (antibody-mediated), Type III (immune-complex: antibody stuck to antigen in clumps), and Type IV (T-cell mediated: driven by T cells, a type of lymphocyte). The types differ in mechanism and speed, which affects how each is recognised and treated.

2. Type 1 Hypersensitivity

• Understand the physiology of type 1 hypersensitivity reactions and how that physiology links to the clinical presentation of allergy.
• Understand the hygiene hypothesis (the idea that less early exposure to microbes may raise the risk of allergy) and its role in the development of allergy.
• Be aware of the symptoms and management of allergic reactions.

3. Food Allergy

• Understand the causes of food allergy and the pathophysiology (how the disease process works in the body) of its different presentations.
• Be aware of the difference between IgE-mediated (driven by immunoglobulin E, the allergy antibody) and non-IgE-mediated allergic reactions.
• Understand how a food allergy can be diagnosed.
• Be aware of the management of food allergy and concepts such as the food ladder (a step-by-step plan for gradually reintroducing the allergen food).
• Be aware of anaphylaxis (a life-threatening medical emergency) and its management.

4. An Introduction to Autoimmunity

• Understand the role of autoimmunity in acute and chronic disease.
• Be aware of the most common autoimmune conditions and how they present.
• Understand potential causes for autoimmune conditions and how they are diagnosed.
• Be aware of the principles used to treat autoimmune conditions.

5. Rheumatoid Arthritis

• Describe RA as a systemic autoimmune disease involving rheumatoid factor (an antibody found in the blood of many people with RA) and anti-CCP (anti-cyclic citrullinated peptide) antibodies.
• Explain how synovitis (inflammation of the joint lining) develops, covering immune complex formation (antibody stuck to antigen in clumps), the cytokines involved (chemical messengers of the immune system: interleukin-1 [IL‑1], tumour necrosis factor alpha [TNF‑α] and interleukin-6 [IL‑6]) and pannus development (pannus is thickened, inflamed joint lining that damages the cartilage and bone).
• Recognise clinical features: symmetrical joint swelling, early morning stiffness, extra‑articular manifestations (effects outside the joints, such as on the skin, lungs and heart).
• Outline diagnostic tools: blood markers (rheumatoid factor [RF] and anti-citrullinated protein antibodies [ACPA], the group of antibodies that the anti-CCP test detects), imaging (X-ray, ultrasound) and the 2010 ACR/EULAR classification criteria (a points score that supports, but does not replace, clinical diagnosis).
• Summarise treatment strategies: DMARDs (disease-modifying anti-rheumatic drugs, which slow the disease), biologics (drugs made from living cells that block one specific immune molecule), NSAIDs (non-steroidal anti-inflammatory drugs, for pain and inflammation), steroids, physiotherapy.
• Understand the effects of RA beyond the joints: anaemia of chronic disease (anaemia caused by long-term inflammation) and a higher risk of cardiovascular disease.

• Be able to describe the autoimmune basis and multisystem nature (effects on many organs) of SLE
• Be able to recognise common clinical features and interpret key investigations
• Be able to outline management principles, monitoring and major complications

• Be able to classify immunological therapies and explain how they work, with monoclonal antibodies (lab-made antibodies that target one specific molecule) as a key example
• Be able to identify common clinical uses and therapeutic examples
• Be able to recognise important adverse effects and monitoring requirements