What is the number one effect allogenic transfusion have on a recipient's immunologic functions?

Allogenic transfusion refers to the process of transferring blood products from one individual to another. A significant immunologic effect of allogenic transfusion is the alteration in cytokine production. Specifically, it has been observed that allogenic transfusions can decrease the production of Th1 cytokines while increasing Th2 cytokines.

Th1 cells are typically involved in cell-mediated immune responses, including those that combat intracellular pathogens and contribute to the development of a robust immune response. In contrast, Th2 cells are more associated with humoral immunity and are involved in responses to extracellular pathogens, such as parasites, and in the regulation of allergic responses.

The shift from Th1 to Th2 cytokine production following an allogenic transfusion can lead to a decreased ability to mount effective cell-mediated immune responses, potentially impairing the recipient's capacity to respond to infections or foreign antigens. This immunomodulatory effect can have clinical implications, such as an increased risk of infections or complications following surgery.

In summary, the alteration in cytokine profiles, particularly the decrease in Th1 cytokines and the increase in Th2 cytokines, serves as a key marker of how allogenic transfusion impacts a recipient's immunologic functions.