Double Filtration Plasmapheresis In The Treatment Of Myasthenia Gravis: Effects And Possible Mechanism

AIMS:To investigate the mechanism and clinical effect of double filtration plasmapheresis(DFPP) in the treatment of myasthenia gravis.METHODS:In the first part,40 patients were involved to evaluate the change of peripheral auto-antibodies(AChR-ab,PrsmR-ab,Titin-ab) and their correlation with Quantitive MG Scores(QMG scores) before and at follows up visits after each treatment.The curative effects of DFPP,IA(Immuno Adsorption) and IVIG (Intravenous Immunoglobulin) were also compared to value the clim'cal efficacy of DFPP.The second part was to investigate the possible mechanism of DFPP.By using flow cytometry five patients were analyzed on CD4+CD25+Foxp3+ T cells before and after treatment as well as IL-4 and TGF-βon the surface of CD4+ T cells.Five volunteers were also involved.Serum and supernatant Interleukin 2(IL-2),IL-4, IL-10,Transforming Growth Factorβ(TGF-β),Interferonγ(IFN-γ),Intercellular Adhesion Molecule 1(ICAM-1) were evaluated by ELISA.RESULTS:In the first part,auto antibodies and QMG scores both decreased in DFPP,IA and IVIG group,of which DFPP and IA had a larger amplitude.The fall of Titin-ab correlated with QMG score.Serum IgA and IgM level was lower in DFPP group than in IA after treatment.In the second part,CD4+CD25+Foxp3+ T cells were found increased after DFPP. Serum ICAM-1 decreased after treatment.The levels of IL-4 and TGF-βon the surface of Th2 cells were higher than control group before treatment while no difference was found after DFPP.Despite their varying numbers,no statistic significance of IL-2,IL-10,IFN-γwas seen before and after treatment both in serum and supernatant. CONCLUSIONS:DFPP relieves the symptoms of myasthenia gravis,which is superior to IVIG group in short-term clinical effect.The mechanism of DFPP can be directly related to the removal of auto antibodies and serum ICAM-1 as well as the increased Treg cells,which may lead to the adjustment of immune balance.