"My doctor said I have an autoimmune disease. What does that mean?" asks a client. How should the nurse respond?

A. IgE (Immunoglobulin E): This class of antibodies is primarily involved in hypersensitivity reactions Type I, which are immediate allergic reactions. When a person is exposed to an allergen they are sensitive to, IgE antibodies on the surface of mast cells and basophils bind to the allergen. This triggers the release of inflammatory mediators like histamine, leading to allergic symptoms such as itching, hives, and in severe cases, anaphylaxis.

B. IgA (Immunoglobulin A): IgA antibodies are primarily found in mucosal areas such as the respiratory and gastrointestinal tracts. They play a role in immune defense on mucosal surfaces and are important for preventing infections. While IgA is not directly associated with hypersensitivity reactions Type I, deficiencies in IgA can sometimes lead to increased susceptibility to certain infections.

C. IgG (Immunoglobulin G): IgG antibodies are the most common type of antibody in the bloodstream and are involved in various immune responses, including defense against bacterial and viral infections. IgG antibodies are not specific to Type I hypersensitivity reactions; they are part of the immune system's broader defense mechanisms.

D. IgM (Immunoglobulin M): IgM antibodies are the first antibodies to be produced in response to an infection. They are large pentameric molecules and are effective at agglutinating pathogens. IgM antibodies are involved in the primary immune response to infections, but they are not specifically associated with Type I hypersensitivity reactions.

A. Gentamicin: Gentamicin is an aminoglycoside antibiotic effective against many bacteria, but it's not the first choice for MRSA. Vancomycin or other alternatives are preferred due to the rising resistance of MRSA to gentamicin.

B. Nafcillin: Nafcillin is a penicillin antibiotic, often used for penicillin-sensitive staphylococcal infections. However, it is not effective against MRSA, which is resistant to many penicillin-based antibiotics.

C. Vancomycin: Vancomycin is a glycopeptide antibiotic used to treat a variety of bacterial infections, including MRSA. It works by inhibiting cell wall synthesis in bacteria, making it effective against Gram-positive bacteria that have developed resistance to other antibiotics like methicillin (which MRSA has).

D. Penicillin: Penicillin is a group of antibiotics that includes drugs like amoxicillin and ampicillin. MRSA is resistant to penicillin-based antibiotics, so they are not effective against MRSA infections.