Immune complexes play a huge role in a various of diseases. Physiology, experimental pathology and clinical pathology of immune complexes will be enlighted. Binding of any antigen to antibody, the latter one always an immunoglobulin (Ig), occurs through hydrophobic interaction and exclusion of cations from the antigen-antibody interface. On the side of the antigen this surface is termed epitope, whichever its size an impressive structure nevertheless.
On the side of the antibody the surface is a stealth at the N-terminal of the Ig, part of it alongside contributed by heavy (H) chain and part by light (L) chain of Ig. Electrostatic van der Waals forces, and not chemical linkeages hold antigen and antibody together, like a handshake with a potential for an on and off close encounter.