Novel apoptosis assay to analyze immunosuppression.

BACKGROUND: We developed a novel whole blood assay to assess the effects of immunosuppressants on lymphocyte apoptosis. METHODS: Peripheral blood for six experiments for each drug was treated either with cyclosporin A (CsA), mycophenolate acid (MPA), tacrolimus (TRL) or rapamycin (RAPA). Whole blood was stimulated with different concentrations of staurosporine (0-5 microM) for 24 h. Using FACS, apoptosis were measured by Annexin V expression (%cells +/- SEM). RESULTS: MPA, RAPA, TRL, but not CsA, increased (P < 0.05) apoptotic cells (MPA:20.9 +/- 3.7; RAPA:17.5 +/- 3.3; TRL:16.4 +/- 2.9 vs. control:15.2 +/- 2.8). CONCLUSION: This new whole blood assay exhibited that MPA has a stronger effect on apoptosis than RAPA and TRL, whereas CsA had no effect.