Interleukin-18 among atrial fibrillation patients in the absence of structural heart disease.
OBJECTIVE
Inflammation plays a role in the genesis and perpetuation of atrial fibrillation (AF). Interleukin (IL)-18 is a pleiotropic proinflammatory cytokine with a central role in the inflammatory cascade. We hypothesize that the circulating IL-18 concentration is elevated in AF patients.


RESULTS
In a case-control study design, 56 cases with AF and 26 controls were enrolled. All AF cases were categorized into paroxysmal and persistent AF or lone AF and AF with hypertension. Circulating levels of IL-18, tumour necrosis factor-α, high-sensitivity C-reactive protein, matrix metalloproteinase (MMP)-9, and tissue inhibitor of MMP-1 were measured. In adjusted analyses, only age, MMP-9, and IL-18 were independently associated with AF, in which IL-18 had the most significant association (P = 0.0011, standardized estimate &bgr = 1.76, OR = 1.02, 95% confidence interval: 1.01-1.03). Interleukin-18 levels in persistent AF patients were higher than those in paroxysmal ones (P = 0.0011). Patients who developed AF within 24 h prior to sampling displayed a higher level of IL-18 than those with sinus rhythm (P = 0.0027). Interleukin-18 was positively correlated with left atrial diameter (r = 0.33, P = 0.0117).


CONCLUSIONS
This study documents the elevated IL-18 in AF patients. Interleukin-18 may be superior to other inflammatory markers which are known to be elevated in AF.
Luan
Ying
Y
Department of Cardiology, The Second Affiliated Hospital of Harbin Medical University, Harbin 150086, People's Republic of China.
Guo
Yuanyuan
Y
Li
Shufeng
S
Yu
Bo
B
Zhu
Sui
S
Li
Shaojun
S
Li
Ning
N
Tian
Zhen
Z
Peng
Chenghai
C
Cheng
Jiali
J
Li
Qingsong
Q
Cui
Jinjin
J
Tian
Ye
Y
D000328:Adult; D000368:Aged; D001281:Atrial Fibrillation / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D006331:Heart Diseases / Q000473:pathology*; D006801:Humans; D020382:Interleukin-18 / Q000097:blood*; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D008875:Middle Aged; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000097:blood; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D015415:Biomarkers; D020382:Interleukin-18; D019715:Tissue Inhibitor of Metalloproteinase-1; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein; D020780:Matrix Metalloproteinase 9