RT Journal Article SR Electronic T1 Immune Skew of Circulating Follicular Helper T Cells Associates With Myasthenia Gravis Severity JF Neurology - Neuroimmunology Neuroinflammation JO Neurol Neuroimmunol Neuroinflamm FD Lippincott Williams & Wilkins SP e945 DO 10.1212/NXI.0000000000000945 VO 8 IS 2 A1 Ashida, Shinji A1 Ochi, Hirofumi A1 Hamatani, Mio A1 Fujii, Chihiro A1 Kimura, Kimitoshi A1 Okada, Yoichiro A1 Hashi, Yuichiro A1 Kawamura, Kazuyuki A1 Ueno, Hideki A1 Takahashi, Ryosuke A1 Mizuno, Toshiki A1 Kondo, Takayuki YR 2021 UL http://nn.neurology.org/content/8/2/e945.abstract AB Objective To clarify functional alterations of follicular helper T cells (Tfh) in myasthenia gravis (MG) because Tfh play important roles in helping B cells generate antibody-producing cells.Methods A total of 24 immunotherapy-naive patients with anti–acetylcholine receptor (AchR) antibody–positive MG and 18 age-matched healthy subjects (HS) were enrolled. Samples from 6 patients were available for posttreatment analysis. Subsets of circulating Tfh (cTfh) and B cells were identified by flow cytometry analysis of surface molecules. Cytokine production by isolated cTfh subsets from 5 patients with MG and 5 HS was measured in vitro. Analysis was performed to examine the correlation between the frequency of cTfh subsets and that of plasmablasts and between cTfh subsets and the quantitative MG score.Results cTfh increased with elevated expression of inducible T-cell costimulator (ICOS) in patients with MG. cTfh shifted to Th2 and Th17 over Th1 in MG. ICOShighcTfh produced significantly higher levels of interleukin (IL)-21, IL-4, and IL-17A than ICOSlow cTfh only in patients with MG. The frequency of cTfh within CD4 T cells was more closely associated with disease severity than the serum anti-AchR antibody titer and frequency of plasmablasts within B cells. Abnormalities of cTfh were improved after immunotherapy in parallel with clinical improvement.Conclusions Alternation of cTfh is a key feature in the development of MG and may become a biomarker for disease severity and therapeutic efficacy.Classification of Evidence This study provides Class II evidence that the level of cTfh is associated with disease severity in patients with MG.AchR=acetylcholine receptor; APC=allophycocyanin; CCR=C-C receptor; cTfh=circulating Tfh; CXCR5=C-X-C motif receptor 5; Cy=cyanine; EOMG=early-onset MG; HS=healthy subjects; ICOS=inducible T-cell costimulator; ICOShigh=ICOS high expressing; ICOSlow=ICOS low expressing; IFN=interferon; IL=interleukin; LOMG=late-onset MG; MG=myasthenia gravis; PB=peripheral blood; PBMC=PB mononuclear cell; PE=phycoerythrin; PerCP=peridinin chlorophyll protein; PMA=phorbol 12-myristate 13-acetate; QGM=quantitative MG; SLE=systemic lupus erythematosus; Tfh=follicular helper T cells