Atherosclerosis 222 (2012) 464–467 Contents lists available at SciVerse ScienceDirect Atherosclerosis journa l h omepa g e: www.elsevier.com/locate/atherosclerosis Short communication Different prognostic value of white blood cell subtypes in patients with acute cerebral infarction Jinkwon Kim a , Tae-Jin Song a , Ji Hye Park a , Hye Sun Lee b , Chung Mo Nam b , Hyo Suk Nam a , Young Dae Kim a , Ji Hoe Heo a,∗ a Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea b Department of Biostatistics, Yonsei University College of Medicine, Seoul, Republic of Korea a r t i c l e i n f o Article history: Received 22 December 2011 Received in revised form 29 February 2012 Accepted 29 February 2012 Available online 7 March 2012 Keywords: Leukocyte White blood cell Lymphocyte Stroke a b s t r a c t Objective: We aimed to investigate the relationship of each white blood cells (WBC) subtype with neuro- logic severity and outcome in acute stroke. Methods: We included 779 patients with first-ever acute cerebral infarction within 72 h after symptom onset. We investigated the association between counts for WBC subtypes in peripheral blood at admission and (1) initial stroke severity; (2) early change in stroke severity within one week; and (3) functional outcome at three months. Results: Higher total WBC and neutrophil counts were associated with more severe stroke at admission (p < 0.001). In contrast, lower lymphocyte counts were associated with a lesser improvement during the first week after admission (p < 0.05) and with poor functional outcome at three months (OR = 0.706 per 1000 lymphocyte counts/mm 3 , p = 0.020). Conclusions: Our study merits further investigation on the role of each WBC subtype in ischemic injury and different prognostic value of WBC subtypes measured at admission in acute stroke. © 2012 Elsevier Ireland Ltd. All rights reserved. 1. Introduction White blood cells (WBC) are divided into neutrophils, eosinophils, basophils, lymphocytes and monocytes. Each subtype has a different inflammatory and immunologic function and may contribute differently to the pathophysiology of atherosclerosis and cerebrovascular and cardiovascular diseases [1–3]. However, prog- nostic value of each WBC subtypes in acute cerebral infarction is unknown. We investigated the relationship of total WBC counts and those of each WBC subtype at admission with initial stroke sever- ity, early neurologic outcome, and long-term functional outcome in acute cerebral infarction. 2. Materials and methods 2.1. Study design and participants This was a hospital-based retrospective and observational study. The candidates were 1219 patients admitted from November 2008 ∗ Corresponding author at: Department of Neurology, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemoon-gu, 120-752, Seoul, Republic of Korea. Tel.: +82 2 2228 1605; fax: +82 2 393 0705. E-mail address: jhheo@yuhs.ac (J.H. Heo). to March 2011 with a first-ever acute cerebral infarction and reg- istered in the Yonsei Stroke Registry [4]. We only enrolled patients who visited a hospital within 72 h of symptom. We excluded patients admitted with transient ischemic attack or history of pre- vious stroke and patients with conditions that could influence WBC counts at admission or outcome. Patients were excluded if they (1) developed stroke while being admitted for other medical diseases, (2) were currently using steroids or immunosuppressive agents, (3) had a history of cancer, (4) were infected with the human immun- odeficiency virus, (5) had a history of recent infection from stroke onset (<1 week) or (6) were diagnosed with infection within 72 h from admission because of the possibility of a pre-existing infection prior to blood sampling. 2.2. Clinical data collection and blood sampling Baseline clinical data were collected for all patients. Counts for total WBC and differentiated subtypes (neutrophils, eosinophils, basophils, lymphocytes, monocytes and large unstained cells) were measured immediately after presentation using peripheral venous blood in an automated blood cell counter (ADVIA 2120, Siemens Healthcare, Tarrytown, NY, USA). We included other laboratory results based on prior literature review. Detailed laboratory and clinical variables and definition of risk factors, which were used for this study, are available in supplementary data. 0021-9150/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.atherosclerosis.2012.02.042