Lymphocyte subpopulations in Sjögren's syndrome are distinct in anti-SSA-positive patients and related to disease activity

Multimodal Single-Cell Sequencing of B Cells in Primary Sjögren's Syndrome

OBJECTIVE

B cells are important in the pathogenesis of primary Sjögren's syndrome (pSS). Patients positive for Sjögren's syndrome antigen A/Sjögren syndrome antigen B (SSA/SSB) autoantibodies are more prone to systemic disease manifestations and adverse outcomes. We aimed to determine the role of B cell composition, gene expression, and B cell receptor usage in pSS subgroups stratified for SSA/SSB antibodies.

METHODS

Over 230,000 B cells were isolated from peripheral blood of patients with pSS (n = 6 SSA-, n = 8 SSA+ single positive and n = 10 SSA/SSB+ double positive) and four healthy controls and processed for single-cell RNA sequencing (scRNA-seq) and single-cell variable, diversity, and joining (VDJ) gene sequencing (scVDJ-seq).

RESULTS

We show that SSA/SSB+ patients present the highest and lowest proportion of naïve and memory B cells, respectively, and the highest up-regulation of interferon-induced genes across all B cell subtypes. Differential usage of IGHV showed that IGHV1-69 and IGHV4-30-4 were more often used in all pSS subgroups compared with controls. Memory B cells from SSA/SSB+ patients displayed a higher proportion of cells with unmutated VDJ transcripts compared with other pSS patient groups and controls, indicating altered somatic hypermutation processes. Comparison with previous studies revealed heterogeneous clonotype pools, with little overlap in CDR3 sequences. Joint analysis using scRNA-seq and scVDJ-seq data allowed unsupervised stratification of patients with pSS and identified novel parameters that correlated to disease manifestations and antibody status.

CONCLUSION

We describe heterogeneity and molecular characteristics in B cells from patients with pSS, providing clues to intrinsic differences in B cells that affect the phenotype and outcome and allowing stratification of patients with pSS at improved resolution.

Added value of lymphocyte subpopulations in the classification of Sjögren's syndrome

Sjögren's Syndrome (SjS) is a chronic systemic immune-mediated inflammatory disease characterized by lymphocytic infiltration and consequent lesion of exocrine glands. SjS diagnosis and classification remains a challenge, especially at SjS onset, when patients may have milder phenotypes of the disease or uncommon presentations. New biomarkers are needed for the classification of SjS, thus, we aimed to evaluate the added-value of lymphocyte subpopulations in discriminating SjS and non-Sjögren Sicca patients. Lymphocyte subsets from 62 SjS and 63 Sicca patients were characterized by flow cytometry. The 2002 AECG and the 2016 ACR/EULAR SjS classification criteria were compared with clinical diagnosis. The added discriminative ability of joining lymphocytic populations to classification criteria was assessed by the area under the Receiver-Operating-Characteristic Curve (AUC). Considering clinical diagnosis as the gold-standard, we obtained an AUC = 0.952 (95% CI: 0.916-0.989) for AECG and an AUC = 0.921 (95% CI: 0.875-0.966) for ACR/EULAR criteria. Adding Tfh and Bm1 subsets to AECG criteria, performance increased, attaining an AUC = 0.985 (95% CI: 0.968-1.000) (p = 0.021). Th1/Breg-like CD24^hiCD27⁺ and switched-memory B-cells maximized the AUC of ACR/EULAR criteria to 0.953 (95% CI: 0.916-0.990) (p = 0.043). Our exploratory study supports the potential use of lymphocyte subpopulations, such as unswitched memory B cells, to improve the performance of classification criteria, since their discriminative ability increases when specific subsets are added to the criteria.

World Workshop on Oral Medicine VIII: Development of a Core Outcome Set for Dry Mouth: A Systematic Review of Outcome Domains for Xerostomia

OBJECTIVE

The purpose of this study was to identify all outcome domains used in clinical studies of xerostomia, that is, subjective sensation of dry mouth. This study is part of the extended project "World Workshop on Oral Medicine Outcomes Initiative for the Direction of Research" to develop a core outcome set for dry mouth.

STUDY DESIGN

A systematic review was performed on MEDLINE, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials databases. All clinical and observational studies that assessed xerostomia in human participants from 2001 to 2021 were included. Information on outcome domains was extracted and mapped to the Core Outcome Measures in Effectiveness Trials taxonomy. Corresponding outcome measures were summarized.

RESULTS

From a total of 34,922 records retrieved, 688 articles involving 122,151 persons with xerostomia were included. There were 16 unique outcome domains and 166 outcome measures extracted. None of these domains or measures were consistently used across all the studies. The severity of xerostomia and physical functioning were the 2 most frequently assessed domains.

CONCLUSION

There is considerable heterogeneity in outcome domains and measures reported in clinical studies of xerostomia. This highlights the need for harmonization of dry mouth assessment to enhance comparability across studies and facilitate the synthesis of robust evidence for managing patients with xerostomia.

Clinical significance of anti-SSA/Ro antibody in Neuromyelitis optica spectrum disorders

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune inflammatory disease of the central nervous system (CNS), also described as CNS autoimmune astrocytopathy, due to the production of pathogenic antibodies against aquaporin-4 (AQP4) expressed on the foot of astrocytes. NMOSD coexists with autoimmune diseases and related autoantibodies [anti-Sjogren's syndrome A (anti-SSA)/Ro antibody, anti-Sjogren's syndrome B (anti-SSB)/La antibody, anti-nuclear (anti-ANA) antibodies, anti-double-stranded DNA (anti-dsDNA) antibody, anti-thyroglobulin antibody, and anti-thyroid peroxidase antibody].

OBJECTIVES

No precise conclusion has been drawn on the role of the anti-SSA/Ro antibody in NMOSD. Therefore, the aim of this work was to evaluate whether the anti-SSA/Ro antibody has an impact on the clinical manifestation or prognosis of NMOSD.

METHODS

Data were retrospectively collected from 102 patients with NMOSD diagnosed by experienced neurologists. The study population was divided into two groups based on the serum anti-SSA/Ro antibody status: NMOSD with or without anti-SSA/Ro antibody. The clinical, neuroimaging and laboratory parameters were compared between the two groups, including the neurological symptoms, MRI results, frequency of systemic autoantibodies, Expanded Disability Status Scale (EDSS), and NMOSD relapse rate. The EDSS and relapse were applied as measures of the NMOSD patient prognostic value. Cox regression analysis was used to evaluate the prognostic impact of anti-SSA/Ro antibody on NMOSD.

RESULTS

Among the 102 NMOSD patients, striking differences were observed in the positive rate of AQP4-IgG (89.2% vs. 72.3%, p = 0.046) between those patients with and without the anti-SSA/Ro antibody. In addition, NMOSD patients with anti-SSA/Ro antibody showed the presence of more frequent anti-ANA antibodies (p = 0.002), anti-SSB/La antibody (p < 0.001), anti-dsDNA antibody (p < 0.002), Sjogren's syndrome (SS, p < 0.001) and systemic lupus erythematosus (SLE, p = 0.045). Univariate and multivariate Cox regression analysis were performed to confirm that the anti-SSA/Ro antibody affected the EDSS score and the relapse of NMOSD patients. The analysis of the survival curve revealed that the EDSS score in the NMOSD patients positive for the anti-SSA/Ro antibody reached 4.0 (p = 0.035) and relapsed (p = 0.039) earlier than in the negative group.

CONCLUSION

The anti-SSA/Ro antibody could be associated with disease activity and severe disability in NMOSD.

Discordant Predictions of Extraglandular Involvement in Primary Sjögren's Syndrome According to the Anti-SSA/Ro60 Antibodies Detection Assay in a Cohort Study

Electrophoresis-derived techniques for anti-SSA/Ro60 KDa (anti-SSA) antibodies detection have been progressively replaced by methods using non-native antigens. We aimed to compare the patients’ phenotypes and the occurrence of extraglandular manifestations in primary Sjögren’s syndrome according to the method used to detect anti-SSA antibodies. Sera from patients with a diagnosis of pSS according to ACR/EULAR 2016 criteria between 2008 and 2017 were tested for anti-SSA antibodies using methods with non-native antigens (magnetic bead multiplex assay; line immunoassays) and one with native antigens (counterimmunoelectrophoresis (CIE)). The population was split into three groups according to anti-SSA antibodies status: absence (SSA−), presence in any method except for CIE (SSA+CIE−), and presence in CIE (SSA+CIE+). The patients in the SSA+CIE+ group (n = 70, 42.7%) were ten years younger and presented more immunological activity compared with both the SSA− (n = 80, 48.8%) and SSA+CIE− groups (n = 14, 8.5%). The SSA− and SSA+CIE− groups were poorly distinct. The presence of anti-SSA antibodies solely in CIE was significantly associated with the occurrence of extraglandular manifestations of pSS (HR = 4.45 (2.35–8.42)). Contrary to CIE, methods using non-native antigens to detect anti-SSA antibodies were unable to predict the occurrence of systemic expression of pSS.