Background and purpose: Cerebral microbleeds (CMB) are observed in the elderly and have been regarded as one of the manifestations of small vessel disease. Although inflammatory processes have attracted much attention not only in large-artery disease, but also in small vessel disease, their involvement in CMB remains to be determined. The purpose of this study is to clarify relations between inflammatory marker levels and CMB.
Methods: Four hundred thirty-one patients without histories of cerebrovascular diseases were prospectively enrolled. The presence and number of CMB were assessed on gradient-echo magnetic resonance imaging. As common inflammatory markers, serum levels of high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and interleukin-18 (IL-18) were evaluated.
Results: CMB were found in 65 patients (15%). In 35 patients, at least one CMB was found in deep locations, but 30 patients had strictly lobar CMB. Levels of hsCRP, IL-6, and IL-18 were higher in patients with CMB than in those without. Logistic regression analyses showed that each 1SD increase in each inflammatory marker level was significantly associated with the presence of CMB after adjustment for age and sex, and after additional adjustment for cardiovascular risk factors, silent lacunar infarction, and white matter hyperintensity. The OR (95% CI) of hsCRP, IL-6, and IL-18 was 1.81 (1.35-2.46), 1.73 (1.18-2.61), and 2.41 (1.44-4.52), respectively. Furthermore, the inflammatory marker levels were associated with both deep and lobar CMB.
Conclusions: Higher levels of hsCRP, IL-6, and IL-18 are associated with CMB, in both deep and lobar locations, suggesting the involvement of inflammation in CMB.