Effect of iloprost infusion on the resistance index of renal vessels of patients with systemic sclerosis

Objective. To investigate the effect of iloprost, a stable prostacycline analog, on kidney blood flow in patients with systemic sclerosis (SSc), using color flow Doppler sonography. Methods. The acute effect of the drug was studied in 10 patients with SSc with elevated resistance index (RI) levels (all RI values reported are multiplied by 100). Iloprost was administered intravenously (2 ng/kg/min for a period of 8 h). To study the effects of chronic drug administration, 16 patients with SSc were randomly assigned to 2 groups of 8 cases each. The first group was treated with 9 infusions of iloprost in 6 mo. The second group was treated with slow release nifedipine (40 mg/day) for 6 mo. Results. Interlobar artery RI (median 67 vs 61; p = 0.02) and cortical vessel RI (median 65 vs 54; p = 0.001) were reduced after acute treatment. In chronic drug administration, RI values were not modified by nifedipine, while iloprost reduced the RI of the interlobar (median 69 vs 61; p < 0.03) and cortical arteries (median 66 vs 58; p < 0.01). Conclusion. Our findings suggest iloprost might be useful for treatment of scleroderma renal vasospasm.