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We aimed to explore the effects of low-dose rituximab (RTX) on circulating T- and B-cell lymphocytes and the improvement of clinical symptoms in refractory myasthenia gravis (MG) patients. Fifteen patients with refractory MG were treated with a low dose of 600 mg RTX and were evaluated by serial-clinical scales, flow cytometry of peripheral blood T and B cells, and antibody titer before and after six months of RTX treatment. The quantitative MG score (QMGS), manual muscle testing (MMT), MG-related activities of daily living (MG-ADL) and MG-specific quality-of-life (QOL) were significantly improved and the average steroid-dosage reduction was 40% (p =.001) in refractory MG patients at six months after RTX infusion. Compared to eighteen non-refractory MG patients and eighteen Healthy controls, our study showed that the frequencies of circulating regulatory B cells (Bregs) and regulatory T cells (Tregs) were significantly lower and the expression of B-cell activating factor receptors (BAFF-Rs) was greater in refractory MG patients without RTX treatment. Importantly, 600-mg RTX was sufficient to deplete B cells and maintain low B-cell counts for up to six months after infusion. Additionally, a low dose of RTX further increased the frequencies of Tregs. Hence, there is an immune imbalance in circulating T- and B-cell lymphocytes in refractory MG patients compared to non-refractory MG patients. We conclude that remarkable T- and B-cell lymphocyte imbalance exists in refractory MG. Low-dose RTX can improve myasthenic symptom and deplete B cells and increase Tregs%. Unlabelled Image • Imbalance of T- and B-cell population exists in refractory MG. • Low-dose RTX may be effective in refractory MG. • Low-dose RTX can deplete B cells and increase Tregs%. [ABSTRACT FROM AUTHOR]

We aim to investigate the effect of a low dose of rituximab (RTX) in improving the clinical symptoms of refractory generalized myasthenia gravis (MG). Eight patients with refractory generalized MG were treated with a low dose of 600 mg RTX. Patients were evaluated by serial clinical scales, flow cytometry of peripheral blood B, T and NK cells, immunoglobulin, complement levels and antibody titer. The quantitative MG score (QMGS), manual muscle testing (MMT), MG-related activities of daily living (MG-ADL) and MG-specific quality-of-life (QOL) were recorded at baseline as well as 1, 3, and 6 months after RTX infusion. The initial improvement was recorded at 1 month after treatment. QMGS, MMT and MG-ADL were significantly improved and the average steroid dosage reduction was 43% ( p = 0.018) at 6 months. 600 mg RTX was sufficient to deplete B cells and maintain low B-cell counts until 6 months after infusion. Treatment with RTX did not result in a significant change in the percentage of CD 4 + , CD 8 + T-cells while an average increase in the percentage of NK cells. Our study found successful B cell depletion was parallel to symptoms remission and change in serum C3 and C4 levels. Serum AChR antibody levels were independent of clinical response and not influenced by RTX. Therefore, low dose of 600 mg RTX may be sufficient in depleting B cells, maintaining low B-cell counts and improving the clinical symptoms of MG in 6 months. [ABSTRACT FROM AUTHOR]

Myasthenia Gravis (MG) is a T cell-driven, autoantibody-mediated disease. Here we show that oral Berberine (BBR) ameliorated clinical symptoms of experimental autoimmune myasthenia gravis(EAMG) rat model via decreasing the frequencies of Th1, Th17, Th1/17 cell subsets. JAK-STAT pathway was highlighted by transcriptomic analysis with EAMG mononuclear cells (MNCs). Surface plasmon resonance identified ligand binding interaction between BBR and JAK2, and electrostatic interaction was proposed by molecular dynamic simulation. Reduced phosphorylated JAK1/2/3 and STAT1/3 in MNCs from BBR-fed EAMG rats were demonstrated. These results suggest that BBR might improve EAMG by rebalancing T cell subsets through targeting JAK-STAT pathway. [Display omitted] • Berberine could ameliorate clinical symptoms of EAMG rat model. • Berberine treatment rebalances T helper cell subsets and inhibits JAK-STAT pathway. • There is ligand binding interaction between Berberine and JAK2. [ABSTRACT FROM AUTHOR]

Juvenile-onset myasthenia gravis (JOMG) is a unique clinical subtype in China, featured by a higher prevalence of ocular myasthenia gravis (OMG), higher seronegativity of acetylcholine receptor (AChR) antibodies, and better prognosis than that in adult-onset myasthenia gravis (AOMG). We previously identified low-affinity AChR antibodies in Chinese JOMG patients using cell-based assays (CBAs), indicating a predominantly AChR antibody-positive profile. Here, we further screened AChR antibodies in both Chinese AOMG and JOMG patients by CBAs. We recruited patients with MG who had not received prednisone or immunosuppressive therapies between June 2015 and June 2019, and divided them into AOMG and JOMG subgroups according to their ages at the time of recruitment. Clinical information and blood samples were collected. Serum AChR antibodies were detected by CBAs in HEK293T cells expressing clustered adult and fetal AChRs, as well as by enzyme-linked immunosorbent assays (ELISAs). Differences in AChR antibody profiles between AOMG and JOMG subgroups were determined. A total of 239 patients with MG were enrolled in the present study, including 121 AOMG and 118 JOMG patients. Based on ELISAs, 74.4% of AOMG (90/121) and 59.3% of JOMG (70/118) patients were anti-AChR positive (p = 0.02). However, CBAs yielded equal anti-AChR positivities (p = 0.64), as indicated by 80.2% of AOMG patients (97/121) and 77.1% of JOMG patients (91/118). Furthermore, among AOMG patients, 67.8% (82/121) were positive for both adult and fetal AChR antibodies, 5.8% (7/121) were positive for only adult AChR antibodies, and 6.6% (8/121) were positive for only fetal AChR antibodies, while these rates were 50.8% (60/118), 21.2% (25/118), and 5.1% (6/118), respectively, in JOMG cohorts (p < 0.01). Twenty-nine AOMG patients and 10 JOMG patients underwent IgG subclassification of AChR antibodies, which were all confirmed to be predominantly IgG1. The positive rates of AChR antibodies did not differ between Chinese AOMG and JOMG patients, as revealed by CBAs. Furthermore, the screened AChR antibodies were predominantly IgG1 in both AOMG and JOMG patients. Unlabelled Image • CBA efficiently improve the detection sensitivity of AChR antibodies in both Chinese AOMG and JOMG group. • Chinese JOMG and AOMG share a comparable positive rate of anti-AChR antibodies. • AChR antibodies in both Chinese JOMG and AOMG patients were prominently of IgG1 subclass. [ABSTRACT FROM AUTHOR]

Two potentially related microRNAs (miRNAs; miR-150-5p and miR-146a-5p) were examined after low-dose rituximab (RTX) treatment in patients with acetylcholine receptor antibody (AChR)-positive refractory myasthenia gravis (MG). In this prospective, open-label, and self-controlled pilot trial, 12 AChR-positive refractory MG patients were administrated a single, low dose of RTX and followed up at six months. Results showed that RTX decreased the serum exosomal miR-150-5p, scores on three clinical indices (MGFA, MMT, ADL), and patients' prednisolone requirement. Additionally, CD19+ and CD27+ B cells decreased, showing a strong correlation with miR-150-5p. In conclusion, low-dose RTX is effective for AChR-positive refractory MG treatment. Furthermore, our data support the role of miR-150-5p as a potential biomarker for MG. Unlabelled Image [ABSTRACT FROM AUTHOR]