In Protein Energy Malnutrition which of the following immunoglobulin is reduced most?
**Core Concept**
Protein Energy Malnutrition (PEM) is a condition characterized by inadequate protein and energy intake, leading to impaired growth, development, and immune function. The immune system plays a crucial role in protecting against infections, and PEM can compromise this function by altering the levels of various immunoglobulins.
**Why the Correct Answer is Right**
In PEM, the production of immunoglobulins, particularly IgG, is significantly reduced due to the impaired synthesis and secretion of these proteins. IgG is the most abundant immunoglobulin in the body, providing long-term protection against infections. The reduction in IgG levels in PEM is attributed to the decreased availability of amino acids, which are essential for protein synthesis. Additionally, the impaired gut mucosal barrier in PEM can lead to increased gut permeability, allowing toxins and pathogens to enter the bloodstream and further compromise immune function.
**Why Each Wrong Option is Incorrect**
* **Option A:** IgA is primarily involved in mucosal immunity and is not the most reduced immunoglobulin in PEM.
* **Option B:** IgM is the first immunoglobulin to be produced in response to an infection and is not the most affected in PEM.
* **Option D:** IgE is involved in allergic reactions and is not the primary immunoglobulin affected in PEM.
**Clinical Pearl / High-Yield Fact**
In cases of PEM, the reduction in IgG levels can lead to an increased susceptibility to infections, particularly those caused by encapsulated bacteria such as Streptococcus pneumoniae and Haemophilus influenzae.
**Correct Answer: C. IgG.**