Vasogen's immune modulation therapy (IMT) improves postischemic foot skin blood flow and transcutaneous pO(2) recovery rates in patients with advanced peripheral arterial occlusive disease

Abstract

Aim: Vasogen's immune modulation therapy (IMT)* involves the ex vivo exposure of a sample of autologous blood to 3 oxidative stress factors (heat, an oxidative environment, and ultraviolet light), followed by intramuscular re-injection. The primary objective of this study was to assess the effect of Vasogen's IMT on skin blood flow in patients with symptomatic peripheral arterial occlusive disease (PAOD).

Methods: In a double-blind, placebo-controlled pilot study, 18 patients with moderately advanced PAOD were randomized to receive 2 courses each of 6 intramuscular injections of either saline or Vasogen's IMT over a 9-week period. Dorsal foot skin blood flow was assessed directly using laser Doppler fluxmetry (LDF) and indirectly using measurement of transcutaneous pO(2) (tcpO(2)). Key outcome measures of skin blood flow were, for LDF: resting values, peak postischemic values, and the total time to reach peak values following release from 4 min of total foot ischemia and, for tcpO(2): resting values and the time for tcpO(2) to reach 50% of the pre-ischemia value. Measurements were carried out at baseline, at weeks 3, 6, and 9, and at 2 months post-therapy.

Results: No significant differences were detected between groups for resting or peak postischemic LDF values for dorsal foot skin blood flow. Patients randomised to IMT experienced a progressive decrease in the time to peak postischemic skin blood flow, reaching statistical significance at 2 months. Treated patients experienced a 26.1 s decrease in time to peak blood flow (p=0.026) vs a 7.9 s decrease in the placebo group (p=ns). Similar but less striking results were achieved for tcpO(2) recovery time to 50% of pre-ischemia values (treated group, p=0.035; placebo group, p=ns).

Conclusion: Vasogen's IMT improved recovery rates of postischemic dorsal foot skin blood flow in a group of patients with moderately advanced PAOD, probably due to improved endothelial function.