Initial serum GM-CSF levels are associated with the severity of cerebral small vessel disease in microscopic polyangiitis patients.

Serum cytokine levels were comprehensively measured, and the association with cerebrovascular lesions on brain magnetic resonance imaging (MRI) in microscopic polyangiitis (MPA) patients was investigated. The initial serum granulocyte-macrophage colony-stimulating factor (GM-CSF) levels were significantly higher in the high-grade white matter hyperintensities (WMH) group than those in the low-grade WMH group. In multivariate analyses, high serum levels of GM-CSF were independently associated with high-grade WMH. The initial serum GM-CSF levels correlated positively with the Birmingham Vasculitis Activity Score and semi-quantitative scales of WMH. The initial serum GM-CSF levels were associated with the severity of WMH in MPA patients.