The Volume of the Spleen and Its Correlates after Acute Stroke.
BACKGROUND
Animal studies describe changes in the spleen following a stroke, with an immediate reduction in volume associated with changes in the counts of specific blood white blood cell (WBCs). This brain-spleen cell cycling after stroke affects systemic inflammation and the brain inflammatory milieu and may be a target for emerging therapeutic studies. This study aimed to evaluate features of this brain-spleen model in human patients admitted for acute stroke.


METHODS
Medical and imaging records were retrospectively reviewed for 82 consecutive patients admitted for acute stroke in whom an abdominal computed tomography scan was performed.


RESULTS
Mean ± SD splenic volume was 224.5 ± 135.5 cc. Splenic volume varied according to gender (P = .014) but not stroke subtype (ischemic versus hemorrhagic, P = .76). The change in splenic volume over time was biphasic (P = .04), with splenic volumes initially decreasing over time, reaching a nadir 48 hours after stroke onset, then increasing thereafter. Splenic volume was related inversely to percent blood lymphocytes (r = -.36, P = .001) and positively to percent blood neutrophils (r = .30, P = .006).


CONCLUSIONS
Current results support that several features of brain-spleen cell cycling after stroke described in preclinical studies extend to human subjects, including the immediate contraction of splenic volume associated with proportionate changes in blood WBC counts. Splenic volume may be useful as a biomarker of systemic inflammatory events in clinical trials of interventions targeting the immune system after stroke.
Department of Neurology, University of California, Irvine, California.
Nina L
NL
Chiu
Department of Neurology, University of California, Irvine, California.
Brian
B
Kaiser
Department of Radiological Sciences, University of California, Irvine, California.
Y Vien
YV
Nguyen
Decision Support Services, University of California, Irvine, California.
Susan
S
Welbourne
Department of Radiological Sciences, University of California, Irvine, California.
Chandana
C
Lall
Department of Neurology, University of California, Irvine, California; Anatomy & Neurobiology, Physical Medicine & Rehabilitation, The Sue & Bill Gross Stem Cell Research Center, University of California, Irvine, California. Electronic address: scramer@uci.edu.
Steven C
SC
Cramer
D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D000072226:Computed Tomography Angiography; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D009929:Organ Size; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D013154:Spleen / Q000000981:diagnostic imaging* / Q000276:immunology; D020521:Stroke / Q000097:blood / Q000000981:diagnostic imaging* / Q000276:immunology; D013997:Time Factors; D014057:Tomography, X-Ray Computed
Stroke; inflammation; lymphyocyte; spleen; white blood cell