PT  - JOURNAL ARTICLE
AU  - Ashida, Shinji
AU  - Ochi, Hirofumi
AU  - Hamatani, Mio
AU  - Fujii, Chihiro
AU  - Kimura, Kimitoshi
AU  - Okada, Yoichiro
AU  - Hashi, Yuichiro
AU  - Kawamura, Kazuyuki
AU  - Ueno, Hideki
AU  - Takahashi, Ryosuke
AU  - Mizuno, Toshiki
AU  - Kondo, Takayuki
TI  - Immune Skew of Circulating Follicular Helper T Cells Associates With Myasthenia Gravis Severity
AID  - 10.1212/NXI.0000000000000945
DP  - 2021 Mar 01
TA  - Neurology - Neuroimmunology Neuroinflammation
PG  - e945
VI  - 8
IP  - 2
4099  - http://nn.neurology.org/content/8/2/e945.short
4100  - http://nn.neurology.org/content/8/2/e945.full
SO  - Neurol Neuroimmunol Neuroinflamm2021 Mar 01; 8
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