Use of a non-specific immunomodulation therapy as a therapeutic vasculogenesis strategy in no-option critical limb ischemia patients

Abstract

Background/aims: Inflammatory mediators contribute to the impairment of vasculogenesis by reducing endothelial progenitor cells (EPCs) mobilization in atherosclerotic vasculopathy. We tested the hypothesis that administration of an oxygen/ozone mixture (IMT) might counteract this pathophysiological mechanism and enhance limb tissue perfusion in patients with critical limb ischemia (CLI).

Methods: Randomized patients with rest pain or ischemic ulcers and transcutaneous oxygen tension (TcPO(2)) <40 mmHg and/or toe pressure <50 mmHg received placebo (n=74) or a non-specific immunomodulation therapy (IMT) (n=77), autologous blood exposed to oxygen/ozone gas mixture by intragluteal injection, on day 1, 2, 7, and once a week thereafter for at least 22 weeks. Patients were evaluated for changes in TcPO(2), levels of circulating EPCs (CD34/KDR-positive cells) and inflammation (tumor necrosis factor-alpha-TNF-alpha).

Results: TcPO(2) and CD34/CD133-positive cells increased at 22 weeks in IMT group (P<0.01) whereas no changes were observed in placebo group. TNF-alpha levels decreased at 6 months in IMT group (P<0.001) whereas no changes were observed in placebo group. There was a strong positive correlation between CD34/KDR-positive cells and TcPO(2) (r=0.56, P<0.01). Moreover, there was an inverse correlation between CD34/KDR-positive cells and TNF-alpha (r=-0.51, P<0.01).

Conclusions: Intramuscular injection of IMT may improve wound healing and limb salvage in patients with CLI.