Associations of Interleukin-5 With Plaque Development and Cardiovascular Events

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Highlights • There is strong experimental evidence that IL-5 has a protective role in atherosclerosis but the clinical importance of this remains poorly studied. • In a prospective study involving 696 subjects with a follow-up of close to 17 years we show that baseline plasma levels of IL-5 do not predict risk for coronary events and stroke. • However, subjects with high levels of IL-5 were less likely to have a carotid plaque at the baseline investigation. • Experimental studies using a shear stress-modifying cast to the carotid artery of Apoe−/− mice deficient for IL-5 showed that lack of IL-5 was associated with increased plaque formation at sites of oscillatory blood flow. • The findings are in line with previous experimental observations of an atheroprotective role of IL-5 but do not support the use of IL-5 measurement in cardiovascular risk prediction.
Summary Experimental studies have suggested an atheroprotective role of interleukin (IL)-5 through the stimulation of natural immunoglobulin M antibody expression. In the present study we show that there are no associations between baseline levels of IL-5 and risk for development of coronary events or stroke during a 15.7 ± 6.3 years follow-up of 696 subjects randomly sampled from the Malmö Diet and Cancer study. However, presence of a plaque at the carotid bifurcation was associated with lower IL-5 and IL-5 deficiency resulted in increased plaque development at sites of oscillatory blood flow in Apoe−/− mice suggesting a protective role for IL-5 in plaque development.