PATHOLOGY

Detailed explanation-1: -IgA is the most abundant antibody isotype in mucosal secretions and owes its success in frontline immunity to its ability to undergo transcytosis across epithelial cells.

Detailed explanation-2: -Immunoglobulin A (IgA) secreted by mucosal tissue can bind pathogens efficiently to prevent them from attaching to the mucosa, and the pathogens bound by IgA can be efficiently recognized by phagocytes or bound by complement proteins.

Detailed explanation-3: -The immunoglobulin A (IgA) is the predominant antibody isotype in the mucosal immune system, which widely exists in the gastrointestinal tract, respiratory tract, vaginal tract, tears, saliva, and colostrum. Normally, serum IgA shows a monomeric structure, while the mucosal IgA shows polymeric.

Detailed explanation-4: -Immunoglobulin A (IgA) is the most abundant antibody isotype in the mucosal immune system. Structurally, IgA in the mucosal surface is a polymeric structure, while serum IgA is monomeric. Secretory IgA (sIgA) is one of the polymeric IgAs composed of dimeric IgA, J chain, and secretory component (SC).