What is the primary function of B and T lymphocytes that is impaired in patients with Wiskott-Aldrich syndrome?

The primary function of B and T lymphocytes that is impaired in patients with Wiskott-Aldrich syndrome is humoral immunity. Wiskott-Aldrich syndrome is a X-linked immunodeficiency disorder characterized by a triad of symptoms: eczema, recurrent bacterial infections, and thrombocytopenia. This condition primarily affects B lymphocytes, which are responsible for producing antibodies that circulate in the blood and help neutralize pathogens—a vital aspect of humoral immunity.

In Wiskott-Aldrich syndrome, there is a defect in the WAS protein, which is essential for the signaling pathways involved in the development and function of leukocytes, particularly B cells. As a result, patients experience difficulty mounting appropriate antibody responses to infections. Furthermore, T lymphocytes also play a critical role in coordinating the immune response, and their function can be compromised in this syndrome. However, the hallmark issue is primarily related to the humoral immune response due to impaired B cell function.

In contrast, the other options, such as antigen presentation and cell-mediated immunity, involve different mechanisms of the immune system that are less directly affected in Wiskott-Aldrich syndrome. Antigen presentation is largely the role of antigen-presenting cells like dendritic cells, while cell