Which type of immunoglobulin is found in breast milk?

The Role of Immunoglobulin in Breast Milk
Breast milk is often hailed as the gold standard for infant nutrition, not only for its rich array of nutrients but also for its vital role in immune protection. One of the key components of breast milk is immunoglobulin A (IgA), which plays a crucial role in safeguarding the health of newborns.
What is Immunoglobulin A (IgA)?
IgA is a type of antibody that constitutes about 10-15% of the total serum immunoglobulin in the body. It is predominantly found in mucosal areas, such as the gastrointestinal tract, respiratory tract, and urogenital tract, as well as in secretions like saliva, tears, and notably, breast milk. This antibody is essential for infants, particularly because they are born with an immature immune system that is still developing its defenses against pathogens.
How IgA Functions in Breast Milk
The presence of IgA in breast milk is particularly significant during the early days of an infant’s life. Colostrum, the first milk produced after childbirth, is especially rich in IgA. This immunoglobulin is transported across the lactocyte barrier into the milk, allowing mothers to pass on immunity directly to their babies. When infants consume breast milk, they receive these antibodies, which help to protect them from infections by neutralizing pathogens and preventing their adherence to mucosal surfaces.
The Importance of IgA for Infants
The transfer of IgA through breast milk is crucial for several reasons:
1. Immune Development: IgA helps shape and modulate the infant’s immune system, providing a layer of protection against various pathogens.

2. Pathogen Defense: By coating pathogens, IgA prevents them from entering the infant’s body and causing illness.
3. Long-term Health: The antibodies in breast milk not only protect infants in the short term but also contribute to their long-term health by promoting a balanced immune response.
In summary, immunoglobulin A (IgA) is the primary immunoglobulin found in breast milk, playing a vital role in protecting infants from infections and supporting their immune system development. This unique feature of breast milk underscores its importance as a critical source of nutrition and immunity for newborns.

What is secretory IgA in breast milk?

The plasma cells in the breast secrete IgA specific to the antigens encountered in the maternal gastrointestinal and respiratory tract systems. This secretion of sIgA into breast milk and its transfer to the infant help to overcome the normal delay in production of immune factors by the infant.

What is lactoferrin in breast milk?

Background: Lactoferrin (Lf) is a multifunctional protein and one of the most abundant proteins in human milk. Various factors may affect its concentration in human milk, such as stage of lactation, ethnicity, and diet.

What is IgM, IgG, IgA, IgD, IgE?

There are five immunoglobulin classes (isotypes) of antibody molecules found in serum: IgG, IgM, IgA, IgE, and IgD. They are distinguished by the type of heavy chain they contain.

What does IgA do for the body?

Immunoglobulin A (IgA) is an antibody blood protein that’s part of your immune system. Your body makes IgA and other types of antibodies to help fight off sickness.

Which immunoglobulins are found in breast milk?

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.

What is passed through breast milk?

Almost any drug that’s present in the blood will transfer into breast milk to some extent. Most medications do so at low levels and pose no real risk to most infants. There are exceptions, though. Some drugs can be found in high levels in breast milk.

Which immunoglobulins are present in milk?

The primary immunoglobulin in cow colostrum and milk is IgG, whereas the primary immunoglobulin in human milk is IgA [1]. Nevertheless, bovine IgG from colostrum or milk can be effective as a means of providing passive immunity to protect animals and humans from disease.

What type of antibody is in breast milk?

Of note, immune cells such as B and T lymphocytes, regulatory cells, monocytes/macrophages, neutrophils, natural killer cells and IgA, IgG and IgM antibodies are found in the breast milk (7).

Which immunoglobulin is most abundant in newborns?

Human infants receive the majority of maternal immunoglobulins (Ig), predominantly immunoglobulin G (IgG), via the placenta.

Which type of immunoglobulin is present in tears, saliva, and breast milk?

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. Immunoglobulin G (IgG): This is the most common antibody. It’s in blood and other body fluids, and protects against bacterial and viral infections.