IgA is the antibody found in different body secretions such as saliva, tears, intestinal and respiratory secretions, and colostrum which is the first milk produced by lactating mothers after giving birth. IgA is produced by B cells in the mucous membranes of the body. IgA structure includes molecules that bind together and combine with a special protein. This enables the newly formed IgA molecule to be secreted across epithelial cells lining the various organs and ducts. While IgG is considered the most common class of immunoglobulin, IgA is the antibody class that is synthesized maximum daily by the body. Because IgA is not as stable as IgG, it is present in the body in lower amounts at any given time.