What genetic deficiency is most likely implicated in patients with recurrent infections involving Neisseria species?

• A. C1 esterase inhibitor
• B. Immunoglobulins
• C. Late component of complement
• D. BzMicroglobulin

Answer: (C)

Recurrent infections with Neisseria species, such as Neisseria meningitidis and Neisseria gonorrhoeae, are typically associated with a deficiency in the late components of the complement system, specifically complement components C5, C6, C7, C8, or C9. These components play a critical role in the formation of the membrane attack complex (MAC), which is essential for the lysis of certain bacteria, including Neisseria.

When there is a deficiency in these late complement components, individuals become highly susceptible to infections caused by encapsulated organisms like Neisseria, leading to recurrent and severe infections. The inability to effectively opsonize and clear these pathogens results in a higher risk of infections.

In contrast, deficiencies related to the other answer choices do not specifically predispose individuals to infections with Neisseria species. For example, deficiency in the C1 esterase inhibitor is primarily associated with hereditary angioedema rather than recurrent infections. Immunoglobulin deficiencies can lead to more generalized increased susceptibility to infections but are not exclusively linked to Neisseria. Beta-2 microglobulin is involved in the function of MHC class I molecules and is not specifically linked to Neisseria infections either.

Therefore, a