Study Of The Correlations Between Th1/Th2/Th17/Treg Cytokines And Severity Of Myasthenia Gravis

Objectives:To investigate serum levels of AChR-abs and Th1/Th2/Th17/Treg cytokines and analyse the correlation between AChR-abs and cytokines levels and disease severity. And then, the abilities of proliferation and secretion of cytokines of PBMC isolated from the venous blood of MG patients and healthy controls were compared in vitro, to ensure the correlation between the activated or/and over-activated immune system of MG patient and exacerbation the symptom of MG patient.Methods:Venous blood of MG patients and healthy controls were collected according the including criterias and exclusion criterias. ELISA was used to detect serum AChR-abs, IL-4, IL-6, IL-12p70, IL-17A, IFN-y, TGF-β1of MG patients and/or healthy controls. And the correlation between serum AChR-ab and cytokine levels and disease severity was analyzed. PBMC of MG patients and healthy controls was cultured in the presence or absence of PHA or LPS. The proliferation activity of PBMC was measured by CCK-8and release of AChR-abs, IL-4, IL-6of PBMC culture supernatants were determined by ELISA.Results:1. The serum level of AChR-abs changed with the disease progressed. It was significantly higher in generalized MG patients with exacerbation and generalized MG patients with stable remission compared to ocular MG patients (p<0.01, p<0.05). Moreover, the level of AChR-abs was significantly increased in generalized MG patients with exacerbation, compared to those generalized MG patients with stable remission (p<0.05).2. The serum level of IL-17A, TGF-β1was significantly higher in MG patients, compared to healthy controls (p<0.05, p<0.01). However, the level of IL-17A, TGF-β1 was not significantly different between different subgroups of MG patients (p>0.05, p>0.05). The serum level of IL-4, IL-6of exacerbated generalized MG patients was higher than generalized MG patients with stable remission (p<0.05, p<0.05), while the serum levels of IL-4, IL-6, IL-12p70, IFN-y were not significantly different between MG patients and healthy controls (p>0.05, p>0.05, p>0.05, p>0.05). When analysed the correlation between serum level of IL-4, IL-6and concentration of AChR-abs, QMG scores and ADL scores, we found that there was a significant positive correlation between serum levels of IL-4, IL-6and concentration of AChR-abs, QMG scores, ADL scores (OR=0.297, p<0.05; OR=0.368, p<0.05; OR=0.371, p<0.05; OR=0.421, p<0.01).3. Both PBMC isolated from MG patients and healthy controls were activated to some extent after stimulated with PHA or LPS. However, the percentages of proliferation was not significantly different between these two groups (p>0.05, p>0.05).4. After stimulated by PHA or LPS, levels of AChR-ab of PBMC culture supernatants of MG patients were significantly increased (p<0.01, p<0.01). However, levels of IL-4did not change before and after stimulated by PHA or LPS of MG patients and healthy controls (p>0.05, p>0.05, p>0.05, p>0.05). The level of of IL-6of MG patients was not changed, while the level of IL-6of healthy controls was increased. Levels of IL-6of MG patients and healthy controls were increased after stimulated with LPS (p<0.01, p<0.01), nevertheless, there was no significant difference between these two groups (p>0.05).Conclusion:1. The serum levels of AChR-abs and Thl/Th2/Th17/Treg cytokines changed with the disease progressed. The concentrations of AChR-abs, IL-4, IL-6play an important role in the progress of MG, they may be valuable biomakers reflecting the disease severity. 2. Specific antibodies or antagonists of IL-4or IL-6would be novel therapeutic options in MG patients.3. The activity of proliferation and secretion of PBMC from MG patients stays low. However, they can be activated by non-specific antigens. Activated or/and over-activated immune system of MG patient could play an important role in inducing exacerbation of the symptom of MG patient, the exact mechanisms need further study.