Objective     To study the correlation between the stability of carotid atherosclerosis and levels of monocyte chemotactic factor 4 and protein annexin A1 in patients with acute cerebral infarction.      Methods     One hundred and twenty-four patients with acute cerebral infarction (73 males and 51 females) at the age of 41-88

years (60.8±12.9 years) admitted to Department of Neurobiology

First Affiliated Hospital

Medical College of Xi’an Jiaotong University

from January 2008 to December 2010

were enrolled in this study as an experiment group

and 35 healthy individuals (21 males and 14 females) at the age of 42-79 years (59.3±12.1 years) served as a control group. Thickness of carotid intima-media was measured and types of plaque were detected with color Doppler ultrasound. The number of infarctions in brain was calculated by brain CT. Patients with cerebral infarction were further divided into normal carotid group (n=26)

stable plaque group (n=38)

and unstable plaque group (n=60).  Monocyte chemotactic factor 4 level was measured by enzyme-linked immunosorbent assay

and expression levels of A1mRNA

protein

and AI protein were measure by reverse transcription-polymerase chain reaction（RT-PCR）

immunohistochemistry

and Western blotting

respectively and compared.      Results     The number of brain infarctions

the thickness of intima-media

and the level of monocyte chemotactic factor 4 were significantly higher in stable and unstable plaque groups than in normal group（F=21.36 and 24.5

F=19.8，P0.05）. The expression levels of annexin A1 mRNA and protein were significantly higher in unstable plaque group than in stable plaque group（t=2.19 and 2.876， χ

2

= 9.23， P0.05）.      Conclusion     Monocyte chemotactic factor 4 and annexin A1 protein levels are closely related with the instability of carotid plaques and involved in the occurrence of acute cerebral infarction.