Cytokines release inhibition from activated monocytes, and reduction of in-stent neointimal growth in humans

Objective: Atherosclerosis and restenosis are largely ruled by inflammation. The aim of this study was to test the effects of a short-course, high-dose oral prednisone on the release of interleukin-6 (IL-6) and tumour necrosis factor (TNF)-alpha from circulating monocytes and on the neointimal growth that follows bare metal stent (BMS) implantation. In a sub-group of patients activated NF-kappaB was also evaluated.

Methods: Out of 40 patients with coronary artery disease treated with BMS implantation, 20 were randomly assigned to receive oral prednisone during 40 days according to a standardized protocol. In non-stimulated and stimulated (LPS and PMA) monocytes we evaluated the release of IL-6 and TNF-alpha, and NF-kappaB p50 subunit translocation at baseline, at 10 and 30 days. Late luminal loss (LLL) 9 months after angioplasty was calculated by quantitative coronary angiography.

Results: Plasma concentrations of prednisone correlated inversely with IL-6 and TNF-alpha release (R2=0.45, p=0.04 and R2=0.69, p=0.005, respectively) and NF-kappaB activation from monocytes (R2=0.58, p=0.01). The reduction of TNF-alpha release and NF-kappaB activation were significantly related (R2=0.56, p=0.01). Prednisone patients showed a significantly larger reduction of cytokine release and NF-kappaB activation compared to non-treated patients, at 10 days and 30 days. LLL was lower in the prednisone group (0.44+/-0.35 mm versus 0.80+/-0.53 mm, p=0.02) and correlated with reduction of TNF-alpha (R2=0.41, p=0.01).

Conclusions: High doses of oral prednisone reduce NF-kappaB pathway activation and pro-inflammatory cytokine release in circulating activated monocytes of patients treated with coronary stenting. TNF-alpha release reduction correlates with decreased LLL.