Association of CD40--1C/T polymorphism with cerebral infarction susceptibility and its effect on sCD40L in Chinese population.

This study aims to determine whether functional polymorphism of CD40 is associated with the cerebral infarction (CI) susceptibility, and to investigate the effect of CD40 gene polymorphism on CD40 mRNA expression in PBMCs and plasma sCD40L concentration. A case-control study was performed in 402 CI patients and 693 controls. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The expressions of CD40 mRNA and plasma sCD40L concentration were determined. The distribution of TT genotype and the frequency of T allele in CI patients were significantly higher than those in the controls (P<0.05). The frequency of T allele was also significantly higher in the male subjects and the elder subjects (P<0.05) when stratified analysis was carried out. The PBMCs from CI patients showed significantly higher CD40 mRNA expression than controls (P<0.01), the CD40 mRNA expression from TT genotype was higher than other genotypes (P<0.05). TT genotype subjects also showed the highest plasma sCD40L concentration in the male CI patients (P<0.01). CD40 -1C/T polymorphism may interfere CI susceptibility, and the T allele may be associated with increased risk of CI. The CD40 -1C/T polymorphism is also a regulator of CD40 expression and plasma sCD40L concentration.