Which immunosuppressive therapy predominantly affects T cells while sparing B cells?

Basiliximab is a monoclonal antibody that specifically targets the interleukin-2 receptor (CD25) on activated T cells. By binding to this receptor, basiliximab inhibits the response of T cells to interleukin-2, a key growth factor necessary for T cell proliferation and activation. This selective action primarily suppresses T cell activity while leaving B cells and other immune cells relatively unaffected.

In contrast, mycophenolate mofetil is a broader immunosuppressive agent that inhibits lymphocyte proliferation, affecting both T and B cells. Sirolimus also has immunosuppressive properties but impacts both T and B cell activation through inhibition of the mTOR pathway. Azathioprine is a purine synthesis inhibitor that can affect the proliferation of both T and B lymphocytes as well.

The specific action of basiliximab makes it valuable in settings such as transplantation, where the prevention of T cell-mediated graft rejection is crucial while maintaining B cell function for appropriate antibody responses.