Alterations of peripheral blood B cell subsets in Chinese patients with adult idiopathic inflammatory myopathies

Abstract

ObjectiveAbnormalities and hyperactivation of B cells have been described in idiopathic inflammatory myopathies (IIM). However, little is known about changes in the homeostasis of peripheral blood B cells in adult IIM patients. The aim of this study was to identify phenotypic alterations of B cell subsets and their relation to the overall clinical profile. Methods Blood samples were collected from 25 adult IIM patients and 15 healthy controls. Peripheral B cell subsets were classified into non-switched memory B cells (CD19+CD27+lgD+), switched memory B cells (CD19+CD27+lgD−), double-negative (DN) memory B cells (CD19+CD27−lgD−) and naïve B cells (CD19+CD27−lgD+) based on their surface phenotype as measured by flow cytometry. The clinical profile of IIM and its correlation with B cell subsetswas further evaluated. Results Frequencies of CD19+ B cells and naïve B cells were increased in adult IIM patients compared with healthy controls (p=0.005 and p<0.001, respectively) and the frequency of memory B cells was decreased (p<0.001). Moreover, patients with a rash had lower non-switched memory B cells proportion (p=0.032). Patients with anti-MDA5+ antibodies had higher CD19+ B cells proportion than anti-ARS+ patients (p=0.046). Patients who were not receiving treatment had elevated levels of CD19+ B cells and naïve B cells along with reduced non-switched memory B cells compared withpatients who were receiving treatment (p=0. 021, p=0.036 and p=0.032, respectively). Conclusion Our findings demonstrate abnormalities in the homeostasis of the B cell subsets present in adult IIM patients, characterised by expanded CD19+ B cells and naïve B cells but reduced memory B cells. Phenotypic abnormalitiesof B cell subsets are associated with the presence of a rash, with anti-MDA5 positivity and with treatment.

Peripheral Blood Lymphocyte Subsets and Heterogeneity of B Cell Subsets in Patients of Idiopathic Inflammatory Myositis with Different Myositis-specific Autoantibodies

“…Cluster 3 composed of memory B cells, translational memory B cells, and plasmablast, suggests that increased frequency of memory B cells and plasmablast are associated with patients with anti-MDA5 antibodies. This is consistent with previous studies of abnormalities in B cell subset distribution in patients with IIM [14,25,35]. The results suggest that B cell subsets in IIM are heterogeneous.…”

“…Previously, Jennifer et al [23] explored the function of Jo-1-binding B cells in patients with anti-synthetase syndrome (ASS) by recruiting 110 patients; Jose ne et al [24] analyzed the role of B cell subsets in the pathogenesis of DM by analyzing skeletal muscle biopsies from 23 IIM patients. Furthermore, Wang et al [25] found that dysregulation of B cell subsets was associated with the presence of rash, anti-MDA5 autoantibodies, and treatment e cacy in a cohort of 25 IIM patients.…”

Roles of biomarkers in anti‐MDA5‐positive dermatomyositis, associated interstitial lung disease, and rapidly progressive interstitial lung disease

“… 88 CD19 + B cell counts are higher in MDA5 + DM patients than in ARS + IIM patients. 102 Additionally, serum (ESR) levels are higher in the non‐survival group than in the survival group among MDA5 + DM patients, indicating that increased ESR may predict poor prognosis in MDA5 + DM patients. 103 …”

“…A high monocyte–lymphocyte ratio (MLR) (MLR >0.604) is an independent predictor of mortality in MDA5 + DM‐ILD patients, suggesting that MLR may predict poor prognosis in MDA5 + DM‐ILD patients 88 . CD19 + B cell counts are higher in MDA5 + DM patients than in ARS + IIM patients 102 . Additionally, serum (ESR) levels are higher in the non‐survival group than in the survival group among MDA5 + DM patients, indicating that increased ESR may predict poor prognosis in MDA5 + DM patients 103 …”

Idiopathic inflammatory myopathies: one year in review 2022

“…On the other hand, the immune system's dysregulation is responsible for numerous pathological implications in IIM. In Chinese patients, CD19+ B cells and naïve B cells are expanded, but a small number of memory B cells is found (9). Furthermore, the different levels of the B cell subtypes were different in different clinical subgroups: patients with a rash had lower nonswitched memory B cells.…”