Immunology is the study of the immune system.
The immune system can be involved in disease development in 4 main ways:
Immunodeficiency – inadequate immune response to infection.
The immune system may be functioning poorly which makes us less able to fight off infections.
Immunodeficiency can occur because a component of the immune system is missing or because other factors are stopping it from working properly e.g. cancer, drugs and HIV infection.
Autoimmunity – inappropriate immunological reactivity against self
The immune system may be inappropriately active against the normal body.
Examples of autoimmune diseases include systemic lupus erythematosus (SLE) and vasculitis.
Allergy – inappropriate immunological reactivity against harmless external proteins.
Allergy includes conditions such as asthma, hayfever and anaphylaxis.
Autoinflammatory – abnormal activation of the innate immune system
These are rare familial diseases characterised by seemingly unprovoked episodes of fever and inflammation. Examples include Familial Mediterranean Fever (FMF) and Cryopyrin-Associated Periodic Syndromes (CAPS).