IMMUNOLOGY

Detailed explanation-1: -Type I hypersensitivity is also known as an immediate reaction and involves immunoglobulin E (IgE) mediated release of antibodies against the soluble antigen. This results in mast cell degranulation and release of histamine and other inflammatory mediators.

Detailed explanation-2: -Anaphylaxis is an extreme form of immediate hypersensitivity. It is a life-threatening reaction involving massive histamine release, which can lead to breathing difficulties and low blood pressure.

Detailed explanation-3: -Type II hypersensitivity reaction refers to an antibody-mediated immune reaction in which antibodies (IgG or IgM) are directed against cellular or extracellular matrix antigens, resulting in cellular destruction, functional loss, or damage to tissues. Damage can occur through multiple mechanisms.

Detailed explanation-4: -Anaphylaxis is a life-threatening condition closely linked to IgE activation of mast cells with subsequent release of preformed mediators, including histamine, neutral proteases (tryptase and chymase), and proteoglycans (eg, heparin) from intracellular granules.