Rationale for T cell inhibition by cyclosporin A in major autoimmune diseases.

T cells exert a fundamental role in different autoimmune chronic inflammatory diseases. The low-affinity autoreactive T cell clones provide the first amplification loop after the antigen (AgX) presentation, and if not counterregulated by the T regulatory cells (Treg), they maintain the inflammation and predispose to organ damage. Interrupting the T cell amplification loop through calcineurin antagonists leads to maintenance of the whole process under the autoimmune threshold.