IL-2 antagonists: the European perspective.

Acute rejection remains the main risk factor following intestinal transplantation. New immunosuppressive agents have substantially reduced the incidence of severe acute rejection. The question arises, which is the most powerful immunosuppressive combination with the lowest incidence of side effects? According to International Intestinal Transplant Registry data, anti-IL-2 antibodies are slightly advantageous compared with antilymphocyte preparations with respect to long-term patient survival. However, different antilymphocyte preparations are used in different doses and at different time points. The anti-IL-2 antibodies daclizumab and basiliximab were also used in different protocols. Therefore, final results on efficacy are awaited. The most important difference between IL-2 antibodies and antilymphocyte preparations is the suppression of CD4+ CD25+ T lymphocytes by anti-IL-2 antibodies. Antilymphocyte preparations do not affect CD4+ CD25+ T cells. Because regulatory CD4+ CD25+ T cells are essential for tolerance induction, protocols attempting tolerance may omit anti-IL-2 antibodies in the future.