What adverse impact does long-term glucocorticoid therapy have on the immune system?

Long-term glucocorticoid therapy has a significant adverse impact on the immune system primarily by causing immune system suppression. Glucocorticoids, such as prednisone, work by inhibiting various components of the immune response. This includes downregulating the expression of cytokines, reducing the proliferation of T cells, and affecting the function of macrophages. The result is a decreased ability of the body to respond to infections and an increased susceptibility to opportunistic infections.

This immune suppression is a key factor in the clinical management of conditions like autoimmune diseases, where glucocorticoids are used to reduce inflammation and modulate the immune response. However, while they are effective in controlling these conditions, the downside is that prolonged use can leave patients vulnerable to infections and may make vaccines less effective.

The other options do not accurately reflect the effects of long-term glucocorticoid therapy on the immune system. Instead of enhancing immune function or having no effect, glucocorticoids significantly dampen the immune responses, which underscores the importance of monitoring patients receiving these treatments for signs of infection and adjusting therapy as necessary.