GENERAL HISTOLOGY

Detailed explanation-1: -Immunoglobulin A (IgA) is a type of antibody that mainly functions in the mucosal immune system and serves as the first line of defense in protecting the oral cavity and upper respiratory tract [1, 2]. Because plasma cells in salivary glands produce IgA, there is a large amount of IgA in saliva [3].

Detailed explanation-2: -Secretory immunoglobulin A (SIgA) constitutes the predominant immunoglobulin isotype in secretions, including saliva.

Detailed explanation-3: -It is well known that the salivary IgA is the predominant protein in mucosal humoral response, and it plays a key role in neutralizing toxins and removing pathogenic microorganisms, however, it does not reduce the number of symbiotic bacteria found in human intestine [36].

Detailed explanation-4: -One important use for measuring antigen specific IgM in saliva is during serological surveys when assessing outbreaks of infectious diseases, for instance with the recent COVID-19 outbreak. Similar to IgM, the major source of IgM in saliva is blood, and its entry is through gingival crevicular fluid (GCF).

Detailed explanation-5: -The types of antibodies are: Immunoglobulin A (IgA): It’s found in the linings of the respiratory tract and digestive system, as well as in saliva (spit), tears, and breast milk.