IMMUNOLOGY

Detailed explanation-1: -These maternal milk antibodies include IgA, IgG and IgM isotypes as well as the secretory forms of IgA and IgM. Although all three major classes of immunoglobulins are present in human colostrum and milk, only IgA and IgM are locally produced in the human mammary gland.

Detailed explanation-2: -The median (interquartile range) of IgA concentrations in milk ranged from 0.625 (0.376–0.959) g/l (at 8–9 weeks) to 0.746 (0.408–1.067) g/l (at 51–52 weeks).

Detailed explanation-3: -Specifically, breast milk contains the immunoglobulins IgA, IgM, IgG and secretory versions of IgM (SIgM) and IgA (SIgA). Colostrum in particular includes high amounts of SIgA, which protects a baby by forming a protective layer in their nose, throat, and throughout their digestive system.

Detailed explanation-4: -In addition, breast milk also contains secretory IgM (SIgM), IgM, and IgG antibodies, but in smaller proportions. Like SIgA, there is selective homing to the mammary gland of plasma cells that produce IgM and IgG, which are subsequently transported into breast milk through pIgR.