CD19 + CD21 lo/neg cells are increased in systemic sclerosis-associated interstitial lung disease

• Published in: Clinical and experimental medicine Vol. 22; no. 2; p. 209
• Main Authors: Wilfong, Erin M, Vowell, Katherine N, Bunn, Kaitlyn E, Rizzi, Elise, Annapureddy, Narender, Dudenhofer, Rosemarie B, Barnado, April, Bonami, Rachel H, Johnson, Joyce E, Crofford, Leslie J, Kendall, Peggy L
• Format: Journal Article
• Language: English
• Published: Italy 01-05-2022
• Subjects: Mass cytometry; Systemic sclerosis; Interstitial lung disease; CD21lo B cells
• ISSN: 1591-9528

Interstitial lung disease (ILD) represents a significant cause of morbidity and mortality in systemic sclerosis (SSc). The purpose of this study was to examine recirculating lymphocytes from SSc patients for potential biomarkers of interstitial lung disease (ILD). Peripheral blood mononuclear cells (PBMCs) were isolated from patients with SSc and healthy controls enrolled in the Vanderbilt University Myositis and Scleroderma Treatment Initiative Center cohort between 9/2017-6/2019. Clinical phenotyping was performed by chart abstraction. Immunophenotyping was performed using both mass cytometry and fluorescence cytometry combined with t-distributed stochastic neighbor embedding analysis and traditional biaxial gating. This study included 34 patients with SSc-ILD, 14 patients without SSc-ILD, and 25 healthy controls. CD21
cells are significantly increased in SSc-ILD but not in SSc without ILD (15.4 ± 13.3% vs. 5.8 ± 0.9%, p = 0.002) or healthy controls (5.0 ± 0.5%, p < 0.0001). While CD21
B cells can be identified from a single biaxial gate, tSNE analysis reveals that the biaxial gate is comprised of multiple distinct subsets, all of which are increased in SSc-ILD. CD21
cells in both healthy controls and SSc-ILD are predominantly tBET positive and do not have intracellular CD21. Immunohistochemistry staining demonstrated that CD21
B cells diffusely infiltrate the lung parenchyma of an SSc-ILD patient. Additional work is needed to validate this biomarker in larger cohorts and longitudinal studies and to understand the role of these cells in SSc-ILD.