Interleukin-8 (IL-8) may contribute to the activation of neutrophils in patients with peripheral arterial occlusive disease (PAOD)

Objectives: to investigate the levels of interleukin-8 (IL-8) in patients with peripheral arterial occlusive disease (PAOD) and healthy control subjects both before and after an acute exercise test. Materials and methods: twenty-six patients with intermittent claudication and 22 matched healthy control subjects each had IL-8 levels measured before and after a standard acute treadmill-exercise test. Subjects walked for 10 min or until stopped by claudication pain. Serum IL-8 levels were measured before exercise was commenced and 1, 5 and 10 min after exercise was stopped.Results: patients with PAOD had statistically significantly higher levels of IL-8 than healthy control subjects, before and after an acute exercise test (p <0.00001, Mann–Whitney). Ratios of the change of IL-8 levels post-exercise showed a statistically significant difference at the post-5-min time point (/E2>p =0.005), showing a difference in the change of IL-8 levels at this time point between the patient group and control group. Conclusions: The increased levels and the failure of the cytokine levels to fall by the same extent after exercise in the patient group may be due to a combination of increased neutrophil activation, reduced blood flow and increased cytokine production during ischaemia–reperfusion, which is not observed in the healthy controls.