The immunoglobulin which protects the newborn against enteric infections is?

Tripura CHO - 2021

Child Health Nursing (Pediatrics)

Easy

Appeared in: Tripura CHO - 2021

Explanation

Immunoglobulin A (IgA) is the principal antibody responsible for protecting the newborn's gut.
It is transferred from the mother to the infant through breast milk, with the highest concentrations found in colostrum (the first milk).
This is a form of passive immunity, where IgA coats the mucosal surfaces of the infant's intestines.
This coating acts as a barrier, preventing pathogens like bacteria and viruses from adhering to the gut wall and causing enteric infections.

Option B: IgD is primarily found on the surface of B lymphocytes, where it functions as an antigen receptor. It is not secreted in significant amounts into breast milk and does not play a role in protecting the newborn's gut.
Option C: IgM is the first antibody produced by the fetus and newborn's own immune system. It does not cross the placenta and is not transferred in significant protective amounts via breast milk. Its presence in a newborn's blood indicates an active or recent infection (e.g., an intrauterine infection), rather than passive protection from the mother.
Option D: This option is incorrect because IgA is the specific immunoglobulin that protects the newborn against enteric infections.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Neonatal Immunity and Immunoglobulins as background academic context rather than a clinical decision trigger.
This concept underscores the critical importance of encouraging and supporting breastfeeding, especially during the first few days of life when colostrum is produced.
Nurses play a vital role in educating new mothers about the benefits of colostrum, often called "liquid gold," for providing passive immunity and protecting their babies from infections.
Understanding this mechanism helps explain why formula-fed infants may have a higher incidence of gastrointestinal illnesses compared to breastfed infants.

How to Approach the Question

First, identify the key terms in the question: 'immunoglobulin', 'protects', 'newborn', and 'enteric infections'.
The question asks for the specific antibody providing gut protection to a baby.
Recall the five classes of immunoglobulins (IgG, IgA, IgM, IgD, IgE) and their primary functions, especially in the context of pregnancy and newborns.
Differentiate the routes of passive immunity: IgG crosses the placenta for systemic immunity, while IgA is transferred via breast milk for mucosal immunity.
Since 'enteric infections' refers to the intestines (a mucosal surface), the antibody associated with mucosal secretions and breast milk is the correct answer.
Evaluate the options: IgA is known for mucosal immunity. IgD's role is different. IgM indicates fetal infection, not passive protection. Therefore, IgA is the logical choice.

Concept Tested & Keywords

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