[Expression of Toll-like receptors in thymus of myasthenia gravis patients].
OBJECTIVE
To investigate the expression of Toll-like receptors (TLRs) in thymus of myasthenia gravis (MG) patients and the relationship with clinical features.


METHODS
Thymic specimens of 36 patients received extended thymectomy for MG were divided into three groups by pathological type: 13 thymoma tissues (thymoma group) and 13 thymic tissues adjacent to thymomas (parathymoma group) from 13 cases of MG patients with thymomas, and 23 thymic tissues from MG patients without thymomas (MG nonthymoma group). Twenty-one normal thymic specimens from cardiac surgery were used as controls. The levels of TLR2-4 mRNA were examined by RT-PCR, then the levels of TLR4 mRNA were assayed by real time RT-PCR and their relationship with clinical features were analyzed.


RESULTS
The levels of TLR4 mRNA among the different groups had significant differences, while there was no difference in TLR2 and TLR3 levels. The real time RT-PCR showed that the level of TLR4 mRNA in nonthymoma group was significantly higher than that in control group(0.8544+/- 0.1200 vs 0.6851+/- 0.1524, P=0.018). And so is parathymoma group compared with the thymoma group (0.8214+/- 0.1019 vs 0.7101+/- 0.0916, P=0.005). No significant difference of TLR4 mRNA level was found between the parathymoma and nonthymoma groups. Nevertheless, the expression of TLR4 in both groups was increased compared with control group. The levels of TLR4 mRNA had positive correlation with Osserman type(R=0.609; P=0.004) .


CONCLUSIONS
TLR4 may play a key role in the pathogenesis of MG. It was the thymic tissues adjacent to thymomas but not thymomas themselves participated in the onset of MG.
Department of Thoracic and Cardiovascular Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, 610041 People's Republic of China.
Ke
K
Gao
Ying-cheng
YC
Wang
Xiao-hong
XH
Ma
Tao
T
Li
Zhu
Z
Wu
Lun-xu
LX
Liu
Guo-wei
GW
Che
Ying-li
YL
Kou
Yi
Y
Huang
Yun
Y
Wang
D000293:Adolescent; D000328:Adult; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013950:Thymus Gland / Q000378:metabolism*; D051195:Toll-Like Receptor 2 / Q000235:genetics; D051196:Toll-Like Receptor 3 / Q000235:genetics; D051197:Toll-Like Receptor 4 / Q000235:genetics; D051193:Toll-Like Receptors / Q000235:genetics*; D055815:Young Adult
D051195:Toll-Like Receptor 2; D051196:Toll-Like Receptor 3; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors