Genetic association of IL-21 polymorphisms with dilated cardiomyopathy in a Han Chinese population.
BACKGROUND
Autoimmune abnormalities appear to be major predisposing factors for dilated cardiomyopathy (DCM). Interleukin-21 (IL-21) gene polymorphisms have been previously found to be associated with autoimmune diseases. This study aimed to assess the role of IL-21 in DCM in a Han Chinese population.


METHODS
A total of 364 independent DCM patients and 384 unrelated healthy controls were recruited for this case-control association study. rs2055979 and rs12508721 were genotyped by PCR-RFLP. IL-21 plasma levels in samples from DCM and control individuals were evaluated by ELISA. The association between the SNPs and overall survival (OS) was evaluated by Kaplan-Meier analysis. Hazard ratios and 95 % confidence intervals (CIs) were assessed in a Cox regression analysis with adjustment for sex and age.


RESULTS
The T allele frequencies of both SNPs were higher in DCM patients than in controls (p < 0.001). The genotypic frequencies of rs2055979 G > T and rs12508721 C > T were associated with DCM in the codominant, dominant, and recessive models (p < 0.05). IL-21 plasma levels in patients were higher than those of the control subjects (p = 0.009). The TT genotypes of both SNPs were associated with significantly higher plasma levels (prs2055979 = 0.03, prs12508721 < 0.001). Kaplan-Meier analysis showed that the genotypic frequencies of both SNPs were associated with OS in the dominant and the recessive models (p < 0.001). The TT genotypes of both SNPs were associated with the worst OS (p < 0.001).


CONCLUSIONS
Our findings suggest that theIL-21 gene plays an important role in susceptibility to DCM as well as in the clinical outcome of this ailment in the Han Chinese population.
Department of Cardiology, West China Hospital, Sichuan University, 610041, Chengdu, P.R. China.
J
J
Lin
Y
Y
Peng
B
B
Zhou
Q
Q
Dou
Y
Y
Li
H
H
Yang
L
L
Zhang
L
L
Rao
D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality*; D002681:China / Q000453:epidemiology; D005260:Female; D056726:Genetic Association Studies; D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D007378:Interleukins / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation / Q000235:genetics; D015995:Prevalence; D018570:Risk Assessment; D015996:Survival Rate; D000098546:Interleukin-21
D005819:Genetic Markers; D007378:Interleukins; D000098546:Interleukin-21