58. Which one of the following Immunoglobulins cause type 1 allergic reaction?
A. IgG
B. IgM
C. IgE
D. IgA

Introduction: Immunoglobulins Involved in Type 1 Allergic Reactions

Type 1 allergic reactions, also known as immediate hypersensitivity reactions, are triggered by the body’s immune system when it overreacts to harmless substances. These reactions are typically mediated by specific immunoglobulins that recognize allergens and initiate the allergic response. Understanding the immunoglobulins involved in these reactions is crucial for managing and treating allergic conditions.

Immunoglobulins and Their Role in Allergic Reactions

The immune system produces five different classes of immunoglobulins (antibodies): IgG, IgA, IgM, IgE, and IgD. Each of these immunoglobulins plays a distinct role in immune responses, with some being more involved in allergic reactions than others.

A. IgG (Immunoglobulin G)

• Function: IgG is the most common type of antibody in blood circulation. It is primarily involved in neutralizing pathogens and activating the complement system for immune defense. It does not play a significant role in type 1 allergic reactions.

B. IgM (Immunoglobulin M)

• Function: IgM is the first antibody produced by the immune system when it detects a pathogen. It is mainly involved in initial immune responses and is found in blood and lymph. However, IgM is not the immunoglobulin involved in type 1 allergic reactions.

C. IgE (Immunoglobulin E)

• Function: IgE is the key immunoglobulin in type 1 allergic reactions. When a person with an allergy is exposed to an allergen (e.g., pollen, pet dander), their immune system produces IgE antibodies. These antibodies bind to mast cells and basophils, which are immune cells involved in allergic responses. Upon subsequent exposure to the allergen, IgE triggers the release of histamines and other chemicals, causing inflammation and the typical allergic symptoms (e.g., sneezing, itching, swelling). This makes IgE the primary immunoglobulin responsible for type 1 allergic reactions.

D. IgA (Immunoglobulin A)

• Function: IgA is mainly found in mucosal areas such as the respiratory and gastrointestinal tracts. It plays a critical role in protecting mucous membranes from infections but is not involved in type 1 allergic reactions.

Conclusion:

IgE (Immunoglobulin E) is the immunoglobulin primarily responsible for mediating type 1 allergic reactions. It is essential for recognizing allergens and triggering the immune system’s inflammatory response, which leads to the symptoms associated with allergies.

Answer:

C. IgE