Increased expression of microRNA-21 in peripheral blood mediates the down-regulation of IFN-γ and increases the prevalence of stroke-associated infection.
BACKGROUND
Increasing levels of microRNA (miRNA)-21 can lead to IFN-γ deficiency, thereby suppressing immune function. Whether changes in the peripheral blood expression of miRNA-21 in patients with acute stroke are related to stroke-associated infection (SAI) remains unsettled.


METHODS
MiRNA-21 and IFN-γ expression levels in peripheral blood plasma were measured in stroke patients presenting within 24h of symptom onset to assess whether these expression levels are associated with the prevalence of SAI.


RESULTS
The stroke with SAI group had significantly higher miRNA-21 expression and lower IFN-γ levels than the stroke without SAI group (p<0.05). A significant negative correlation was observed between miRNA-21 expression and IFN-γ levels (r=-0.303, p=0.026). ROC curves were constructed to measure the performance of the miRNA-21 and IFN-γ to judge SAI. The areas under the ROC curve (AUC) for miRNA-21 and IFN-γ were 0.667 (95% CI, 0.525 to 0.798, p=0.028) and 0.698 (95% CI, 0.558 to 0.816, p=0.005), respectively. The optimal cutoff value was miRNA-21>0.53 and IFN-γ≤72.57pg/ml. There was a significantly different prevalence of SAI between the high miRNA-21 group and the low miRNA-21 group (p=0.008, log rank test). There was also a significant difference between the high IFN-γ group and the low IFN-γ group (p=0.003, log rank test).


CONCLUSIONS
Plasma up-regulated miRNA-21 and decreased IFN-γ in acute stroke can be considered new biological predictors for SAI and thus, new therapeutic targets.
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Shao-Peng
SP
Lin
Department of Geriatrics, The Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Shan
S
Ye
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Xiao-Hui
XH
Chen
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Hui-Lin
HL
Jiang
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Hai-Feng
HF
Mao
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Mei-Ting
MT
Chen
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Qiu-Jie
QJ
Ma
Department of Neurology, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Youming
Y
Long
Department of Neurology, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China.
Yongxiang
Y
Fan
Department of Emergency, the Second Affiliated Hospital of Guangzhou Medical University, 250# Changgang East Road, Guangzhou 510260, Guangdong Province, China. Electronic address: linpeiyi@163.com.
Pei-Yi
PY
Lin
D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood; D001774:Blood Chemical Analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007239:Infections / Q000097:blood* / Q000150:complications* / Q000453:epidemiology; D007371:Interferon-gamma / Q000097:blood*; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D008297:Male; D035683:MicroRNAs / Q000097:blood*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015995:Prevalence; D012372:ROC Curve; D020521:Stroke / Q000097:blood* / Q000150:complications* / Q000453:epidemiology / Q000276:immunology
D015415:Biomarkers; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D007371:Interferon-gamma
IFN-γ; Infection; MicroRNA-21; Stroke