IV IG is primarily used in the treatment of which immunodeficiency disorder?

• A. Common variable immunodeficiency
• B. X-linked agammaglobulinemia
• C. Severe combined immunodeficiency
• D. Hyper-IgM syndrome

Answer: (B)

Intravenous immunoglobulin (IVIG) is primarily used in the treatment of individuals with X-linked agammaglobulinemia. This condition is characterized by an inability to produce antibodies due to a mutation in the BTK gene, which is critical for B-cell development. As a result, individuals with this disorder have very low levels of immunoglobulins and are at increased risk for recurrent bacterial infections.

The administration of IVIG provides these patients with a pooled source of antibodies derived from healthy donors, thus offering immediate passive immunity. This can significantly reduce the incidence of infections and improve overall health and quality of life for patients with X-linked agammaglobulinemia.

While IVIG can be used in other immunodeficiency disorders, its primary indication for X-linked agammaglobulinemia is due to the nature of the antibody deficiencies present in this condition, making it the most relevant treatment option for restoring immunologic function in affected patients.