1065. Describing CD163 as a Biomarker for Intraventricular Extension of Intracerebral Hemorrhage

Authors: Andrew L. Garton; Vivek Gupta, BA; Akshay Save, BS; Brandon Christophe, BA; Edward Connolly, MD (New York, NY)

Introduction: CD163 is a macrophage- and neuron-bound hemoglobin receptor that is upregulated following intracerebral hemorrhage (ICH). This scavenger receptor promotes hematoma reabsorption and facilitates neurological recovery in ICH. Patients with poorer outcomes have been observed to have higher circulating CD163 levels initially, though this effect attenuates at seven days. In animal models, CD163 is observably upregulated after intraventricular injection of hemoglobin, though few human studies have corroborated this finding. This study, therefore, addresses how intraventricular involvement may affect CD163 levels in ICH patients. Methods: Forty-one subjects derived from a larger cohort of 575 patients presenting with nontraumatic ICH had serum samples collected on days 1, 3, and 7 post-admission. Inclusion criteria for this analysis were availability of serum samples and access to complete imaging data, including LeRoux/Graeb scores, and IVH/hematoma volume. ELISA immunoassays for serum CD163 were performed on these serum samples. Results: CD163 levels on days 1 and 3 and on days 3 and 7 were positively correlated (r = 0.66, p < 0.001; r = 0.33, p = 0.049, respectively). ANOVA testing revealed no statistically significant difference in mean concentrations between days, although there was a downward trend from day 1 to 7. LeRoux and Graeb scores, hematoma/IVH volume, and IVH score did not correlate with CD163 levels on any day. However, CD163 levels on day 1 and day 7 were positively associated with functional outcomes at 3 months ( r = 0.44, p < 0.01; r = 0.27, p < 0.1). Conclusions: CD163 levels were shown to increase in a severity-dependent fashion following ICH and IVH and correlate with functional outcomes following ICH. While these results suggest that CD163 may not strongly correlate with severity of IVH extension, the study may be underpowered at the present sample size.