目的:粘膜启动的免疫反应可能参与RA的病理生理过程。粘膜表面最丰富的免疫球蛋白是IgA,其中存在两个亚类:IgA1和IgA2。IgA2主要存在于粘膜部位,并已归因于促炎性质。由于IgA亚类可能提供对粘膜受累和促炎机制的见解,我们调查了RA患者血清中的IgA应答.
方法:在两组RA患者中,EAC和改进,通过ELISA测量总IgA1和IgA2。此外,测定RF和抗瓜氨酸化蛋白抗体(抗CCP2)的IgA亚类水平。研究了这些IgA亚类水平与CRP和吸烟的关系。
结果:与健康供体相比,两组RA患者的总IgA1和IgA2均增加。这种增加在血清阳性RA与血清阴性RA中更为明显。对于RF和抗CCP2,可以检测到IgA1和IgA2两者。在IgA亚类之间没有发现强关联(总计,RF和抗CCP2)和CRP。在吸烟的RA患者中,观察到总IgA2和RFIgA1和IgA2有选择性增加的趋势.
结论:RA患者的IgA1和IgA2水平升高。没有观察到向IgA2的转移,表明总IgA的增加不是由于粘膜IgA易位到血流中。然而,粘膜炎症可能起作用,考虑到吸烟和总IgA2水平之间的关联。尽管具有促炎特性,在RA患者中,IgA2与促炎标志物没有强烈关联。
Mucosal initiated immune responses may be involved in the pathophysiology of RA. The most abundant immunoglobulin at mucosal surfaces is IgA, of which two subclasses exist: IgA1 and IgA2. IgA2 is mainly present at mucosal sites and has been ascribed pro-inflammatory properties. As IgA subclasses might provide insights into mucosal involvement and pro-inflammatory mechanisms, we investigated IgA responses in sera of RA patients.
In two cohorts of RA patients, the EAC and IMPROVED, total IgA1 and IgA2 were measured by ELISA. Furthermore, IgA subclass levels of RF and anti-citrullinated protein antibodies (anti-CCP2) were determined. The association of these IgA subclass levels with CRP and smoking was investigated.
Total IgA1 and IgA2 were increased in RA patients compared with healthy donors in both cohorts. This increase was more pronounced in seropositive RA vs seronegative RA. For RF and anti-CCP2, both IgA1 and IgA2 could be detected. No strong associations were found between IgA subclasses (total, RF and anti-CCP2) and CRP. In smoking RA patients, a trend towards a selective increase in total IgA2 and RF IgA1 and IgA2 was observed.
RA patients have raised IgA1 and IgA2 levels. No shift towards IgA2 was observed, indicating that the increase in total IgA is not due to translocation of mucosal IgA into the bloodstream. However, mucosal inflammation might play a role, given the association between smoking and total IgA2 levels. Despite its pro-inflammatory properties, IgA2 does not associate strongly with pro-inflammatory markers in RA patients.