We evaluated the effect of an in vivo weekly iloprost treatment on TNF-alpha and IL6 monocyte production (evaluated by ELISA), on monocyte apoptosis (Annexin V/uptake of propidium iodide by flow cytometry) and on peripheral blood mononuclear cell (PBMC) TNF-alpha receptors (TNF-RI and TNF-RII) mRNA expression (RT-PCR) in 14 atherosclerotic critical limb ischemia patients.PBMC were stimulated with LPS for 24h.