寻常型天疱疮患者及一级亲属抗体IgG亚型检测

Detection of Antibody IgG Subclasses in Patients with Pemphigus Vulgaris and Their First Degree Relatives

目的观察寻常型天疱疮(pemphigus vulgaris,PV)患者和一级亲属血清中PV自身抗体(PV-IgG)亚型及其与桥粒芯糖蛋白(desmoglein,Dsg)反应性,探讨PV-IgG检测的临床意义和PV的发病机制。方法用间接免疫荧光法(indirect immunofluorescence,IIF)检测27例PV患者、40例一级亲属和20例正常对照者血清PV-IgG,并用免疫印迹法(Westernblot,WB)检测PV-IgG亚型及其与Dsg1、Dsg3反应性。结果PV患者的PV-IgG阳性率和平均抗体滴度明显高于其一级亲属者(P<0.001),活动期患者的PV-IgG阳性率和平均抗体滴度也明显高于缓解期(P<0.01);PV患者中PV-IgG阳性率(92.9%)明显高于一级亲属(17.5%)和正常对照组(0%)(P<0.0001,0.001),PV患者中Dsg3反应性IgG4水平明显高于一级亲属(P<0.01),且其在活动期病例中水平也明显高于缓解期(P<0.05)。结论本病的发生与PV-IgG水平有关;Dsg3是PV的主要自身抗原;IgG4是PV的主要致病抗体。

Objective To observe pemphigus vulgaris（PV） autoantibody（PV-IgG）subclasses and their reactivity with desmoglein （Dsg） in PV patients and their first degree relatives, and to investigate the clinical significance of PV-Ab detection and the pathogenesis of PV. Methods Serum PV-Ab levels, and PV-IgG subtypes and their reactivity with Dsg1 and Dsg3 in 27 PV patients, 40 first degree relatives and 20 healthy individuals were determined by indirect immunofluorescence （IIF） and Western blotting（WB）, respectively. Results The frequency and average titer of PV-Ab in PV patients were significantly higher than those in the first degree relatives（P0.001）, and so did between active and recovery stages（P0.01）. The detection rate of PV-IgG in PV patients（92.9%）was superior to that in the first degree relatives （17.5%） and normal controls （0%）（P0.000 1, 0.001）. Dsg3-reactive IgG4 level was remarkably higher in PV patients and active cases than that in the first degree relatives and remission cases, respectively （P0.01-0.05）. Conclusion The upregulation of PVIgG production is implicated in the pathogenesis of PV. Dsg3 is the major autoantigen. IgG4 is a prerequisite for the pathogensis of PV, whereas IgG1, IgG2 and IgG3 may only take part in the process.