Abstract T P80: Correlates of Spleen Volume After Stroke

Introduction: Inflammatory events have a major influence on acute injury and on neural repair after stroke, and may also be important mediators of treatment effects for some cellular therapies. Preclinical studies suggest that splenic events may be important to the evolution of post-stroke inflammation, and that reduced splenic volume may be a useful marker of these events. The current study extended these findings to humans by examining spleen volumes and their clinical correlates in patients admitted for stroke in order to test the hypothesis that splenic volume is related to 4 variables of interest (1) time post-stroke, (2) level of blood lymphocytes, (3) level of blood neutrophils, and (4) volume of cerebral infarct. METHODS: This retrospective study examined patients admitted for a new stroke between 2006-2011 at a single institution who also had an abdominal CT scan performed. Clinical data were extracted from medical records. Splenic volume was measured from abdominal CT scan by radiologists with expertise in abdominal imaging. Infarct volumes were calculated from brain CT or MRI. RESULTS: A total of 90 patients were identified, 4 of whom had abdominal CT prior to stroke, leaving 86 patients. These 86 had age 66 ± 14 yr (mean ± SD), gender 51M/35F, and infarct volume 51 ± 70 cc. Infarcts were ischemic in 58 (67%), 7 of whom (12%) received tPA, and intracerebral hemorrhage in 28 (33%). Spleen volumes were 225±137 cc, and correlated with gender (M>F, p<0.03), but not with age or stroke subtype. In terms of the variables of interest, splenic volume correlated with % lymphocytes (r=-0.27, p<0.02) and % neutrophils (r=0.23, p<0.04), but not with time post-stroke or infarct volume. CONCLUSIONS: Among patients admitted for stroke, a smaller spleen was found in relation to high lymphocyte and lower neutrophil levels in the blood, consistent with prior findings in rodents and in humans. Although the retrospective nature of the current study introduces potential for bias, these results further suggest that splenic events may be important to inflammatory events arising after stroke.