Differences in immunophenotypes between myasthenia gravis patients with and without thyroid antibodies

Abstract

Introduction/Aims Immunophenotypes are related to the therapeutic efficacy of specific immunomodulating agents in patients with myasthenia gravis (MG), but the relationship of immunophenotype to the presence or absence of thyroid antibodies is unknown. This study aims to evaluate differences in the immunophenotypes between MG patients with and without thyroid antibody (TAb) positivity to provide insight for future targeted immunotherapies. Methods This retrospective observational study included 48 MG patients with acetylcholine receptor antibody (AchR‐Ab), of which 15 (31.25%) were TAb positive. Ocular MG (OMG) was defined as ocular‐only manifestations for the duration for which records were available. Peripheral lymphocyte subpopulations were measured by flow cytometry. Results TAb positive patients appeared to have a higher prevalence of OMG than TAb negative patients (53.33% vs. 24.24%, p = .048). Percentages of B cells (mean difference (MD) = 6.16, 95% confidence interval (CI): 1.91–10.40, p = .007) and CD8 + CD28+ cells (MD = 15.14, 95%CI: 5.17–25.11, p = .013) were higher in TAb positive patients than those in TAb negative patients, while AChR‐Ab titers (MD = −6.49 nmol/L, 95%CI: −9.29 to −3.70, p < .001), percentages of T cells (MD = −6.43, 95%CI: −11.92 to −0.94, p = .023), CD3 + HLA‐DR+ cells (MD = −6.47, 95%CI: −12.31 to −0.63, p = .031) and CD8+ T cells (MD = −6.60, 95%CI: −9.86 to −3.34, p < .001) were lower. Discussion The immunophenotypes of MG patients with and without TAb positivity were significantly different, suggesting that their sensitivity to immunotherapy may be different. Further studies focused on differences between TAb positive and TAb negative MG patients in their responses to specific immunotherapies are needed to support our exploratory findings.

An angel or a devil? Current view on the role of CD8+ T cells in the pathogenesis of myasthenia gravis

“…MG usually coexists with several diseases. In autoimmune thyroid diseases, compared with thyroid antibody (TAb)-negative patients, TAb-positive patients appeared to have a higher prevalence of OMG, higher percentages of CD8 + CD28 + cells, lower AChR-Ab titers, and percentages and absolute counts of total CD8 + T cells [ 44 ]. In patients with Sjogren’s syndrome, CD8 + cells and their two subsets significantly increased in untreated patients with MG.…”