What is Antigen-antibody complex mediated hypersensitivity is - and explain in detail?
a) Type I reactions (immediate hypersensitivity) → Involve immunoglobulin ‘E’(IgE) mediated release of Histamine and other mediators from mast cells and basophils.
b) Type II reactions (Antibody-mediated) → Involve immunoglobulin G or Immunoglobulin M bound to cell surface antigen, with subsequent complement fixation.
c) Type III reactions (Immune complex-mediated) → involve circulating antigen-antibody complexes that deposit in postcapillary venules, with subsequent complement fixation.
d) Type IV reactions (delayed hypersensitivity cell-mediated) → Mediated by T-cells.