Peripheral eosinophil trends and clinical outcomes after non-traumatic subarachnoid hemorrhage

Hugo Gonzalez Gomez; Jude P J Savarraj; Atzhiry S Paz; Xuefang Ren; Hua Chen; Louise D McCullough; Huimahn A Choi; Aaron M Gusdon

doi:10.3389/fneur.2023.1051732

Peripheral eosinophil trends and clinical outcomes after non-traumatic subarachnoid hemorrhage

Front Neurol. 2023 Feb 21:14:1051732. doi: 10.3389/fneur.2023.1051732. eCollection 2023.

Authors

Hugo Gonzalez Gomez¹, Jude P J Savarraj¹, Atzhiry S Paz¹, Xuefang Ren¹, Hua Chen¹, Louise D McCullough², Huimahn A Choi¹, Aaron M Gusdon¹

Affiliations

¹ Division of Neurocritical Care, Department of Neurosurgery, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, United States.
² Department of Neurology, McGovern School of Medicine, University of Texas Health Science Center, Houston, TX, United States.

Abstract

Background/objective: Uncontrolled systemic inflammation after non-traumatic subarachnoid hemorrhage (SAH) is associated with worse outcomes. Changes in the peripheral eosinophil count have been linked to worse clinical outcomes after ischemic stroke, intracerebral hemorrhage, and traumatic brain injury. We aimed to investigate the association of eosinophil counts with clinical outcomes after SAH.

Methods: This retrospective observational study included patients with SAH admitted from January 2009 to July 2016. Variables included demographics, modified Fisher scale (mFS), Hunt-Hess Scale (HHS), global cerebral edema (GCE), and the presence of any infection. Peripheral eosinophil counts were examined as part of routine clinical care on admission and daily for 10 days after aneurysmal rupture. Outcome measures included dichotomized discharge mortality, modified Ranked Scale (mRS) score, delayed cerebral ischemia (DCI), vasospasm, and need for ventriculoperitoneal shunt (VPS). Statistical tests included the chi-square test, Student's t-test, and multivariable logistic regression (MLR) model.

Results: A total of 451 patients were included. The median age was 54 (IQR 45, 63) years, and 295 (65.4%) were female patients. On admission, 95 patients (21.1%) had a high HHS (>4), and 54 (12.0%) had GCE. A total of 110 (24.4%) patients had angiographic vasospasm, 88 (19.5%) developed DCI, 126 (27.9%) had an infection during hospitalization, and 56 (12.4%) required VPS. Eosinophil counts increased and peaked on days 8-10. Higher eosinophil counts on days 3-5 and day 8 were seen in patients with GCE (p < 0.05). Higher eosinophil counts on days 7-9 (p < 0.05) occurred in patients with poor discharge functional outcomes. In multivariable logistic regression models, higher day 8 eosinophil count was independently associated with worse discharge mRS (OR 6.72 [95% CI 1.27, 40.4], p = 0.03).

Conclusion: This study demonstrated that a delayed increase in eosinophils after SAH occurs and may contribute to functional outcomes. The mechanism of this effect and the relationship with SAH pathophysiology merit further investigation.

Keywords: brain injury; eosinophils; inflammation; outcomes; subarachnoid hemorrhage.

Grants and funding

K23 NS121628/NS/NINDS NIH HHS/United States