N-acetylcysteine infusion reduces the resistance index of renal artery in the early stage of systemic sclerosis

Aim: To evaluate resistance index (RI) changes in renal artery after N-acetylcysteine infusion in patients with systemic sclerosis. Methods: In an open-label study 40 patients with systemic sclerosis (SSc) were treated with N-acetylcysteine (NAC) iv infusion over 5 consecutive hours, at a dose of 0.015 g.kg(-1).h(-1). Renal haemodynamic effects were evaluated by color Doppler examination before and after NAC infusion. Results: NAC infusion significantly reduced RI in a group of sclerodermic patients with early/active capillaroscopic pattern, modified Rodnan Total Skin Score (mRTSS) <14 and mild-moderate score to the vascular domain of Medsger Scleroderma Disease Severity Scale (DSS). RI increased after NAC infusion in patients with late capillaroscopic pattern, mTRSS>14 and severe-end stage score to the vascular domain of DSS. In patients with reduction of RI after NAC infusion, diffusion capacity for carbon monoxide mean value was significantly higher than in those patients with an increase of RI. No significant differences in renal blood flow were found between patients with different subsets of SSc. Conclusion: In patients with low disease severity NAC ameliorates vascular renal function.