Elevated Levels Of Cd64 Mfi On Monocyte Subsets Are Associated With A History Of Stroke In Sickle Cell Disease

Background: Ischemic stroke is a cause of morbidity and mortality in children and adults with sickle cell disease (SCD). Recent studies showed that non-classical monocytes may be protective against vaso-occlusive crisis. Monocyte subsets have been examined in non-SCD stroke, but little is known about the role of monocyte or their subsets in ischemic stroke in SCD. CD64 (FCγRI), a high affinity receptor for IgG, is a marker of endothelial adherence on immature neutrophils in SCD, however it is more classically exhibited on activated pro-inflammatory monocytes. We hypothesized that higher levels of CD64 mean fluorescence index (MFI) on monocyte subsets may be associated with ischemic stroke due to increased adherence.