What is the primary pathophysiological mechanism in Good syndrome?

Good syndrome is characterized by a combination of immunodeficiency and autoimmunity, primarily resulting from thymic dysgenesis or dysfunction. In this condition, the thymus, which plays a crucial role in the maturation of T lymphocytes, is affected. This leads to a significant reduction in T cell numbers and function, resulting in a susceptibility to infections and a higher risk of developing autoimmune disorders.

The involvement of the thymus is particularly important in Good syndrome because it affects the body's ability to properly regulate immune responses. The dysfunction can lead to the production of autoantibodies and an inability to maintain self-tolerance, which contributes to autoimmune phenomena. Thus, the primary pathophysiological mechanism of Good syndrome centers on the thymic involvement that leads to both immunodeficiency and autoimmunity.