Abstract TP331: Plasma IL-6 Levels are Independently Associated With Functional Outcome and Markers of Secondary Injury in Spontaneous Intracerebral Hemorrhage

Expression of DEspR in acute intracerebral hemorrhage

OBJECTIVES

Neuroinflammation and secondary injury play a central role in the pathophysiology of intracerebral hemorrhage. The dual endothelin-1/VEGFsignal-peptide receptor (DEspR) has been reported to mediate the inflammatory response after acute brain injury in a rodent model. We performed a pilot study to assess the expression of DEspR on circulating leukocytes in patients who presented with spontaneous intracerebral hemorrhage (ICH).

MATERIALS AND METHODS

We performed a prospective observational study of patients presenting to two academic medical centers with ICH. Normal healthy volunteers (NHV) were also recruited for sample analysis. Whole blood was obtained, and flow cytometry was performed to examine DEspR expression on neutrophils, monocytes, and lymphocytes.

RESULTS

A total of 19 patients were included in analysis. Median ICH volume was 39 cm3 [IQR 19 cm3, 73 cm3] and median ICH score was 2 [IQR 2, 3]. DEspR expression was more abundant on neutrophils (median 2.4% [IQR 0.5%, 5.8%], p = 0.0064) and monocytes (median 4.4% [IQR 1.7%, 15.8%], p = 0.003) relative to lymphocytes (median 0.9% [IQR 0.2%, 3.3%]). ICH patients had higher DEspR expression in all leukocytes relative to NHV (p < 0.05 for all). Among ICH patients, those with a medical history of hypertension showed higher DEspR expression on neutrophils and monocytes (p = 0.018) compared to those without hypertension.

CONCLUSIONS

In this pilot study, DEspR is expressed on circulating neutrophils and monocytes in humans after ICH, with higher levels of expression in those with hypertension. Future work in larger cohorts should examine the relationship of DEspR expression with neuroinflammatory endpoints and long-term outcome.