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How does cyclosporine affect T lymphocytes during transplant treatment?

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Kidney transplant — transplant British surgeon Andrew Ready flushing a donated kidney during a transplant at Queen Elizabeth Hospital, Birmingham, England, 2006.

In the context of transplant surgery, cyclosporine acts as a potent immunosuppressant by inhibiting the function of T lymphocytes, which are the primary white blood cells responsible for cell-mediated immunity and the rejection of transplanted organs.12

Specifically, cyclosporine functions as a calcineurin inhibitor. It targets the intracellular signaling pathways that are triggered when T cells are activated. By inhibiting the enzyme calcineurin, the drug effectively blocks the activation and subsequent function of these T cells. Because transplant rejection is largely driven by T lymphocytes infiltrating and destroying the donor graft, suppressing these cells is essential for preventing the body from attacking the new tissue. Cyclosporine is frequently used in combination with other agents, such as glucocorticoids, to provide comprehensive protection against rejection.12