Sarcoidosis is a heterogenous disease of unknown etiology characterized by non-caseating granulomas. Disease prevalence and presentation vary significantly by ancestry and ranges from acute, self-resolving disease to severe, chronic disease. Following previous reports suggesting B cells in the development and pathogenesis of sarcoidosis, we present here results of single-cell RNA sequencing, supporting B cell involvement in sarcoidosis through altered immediate early response, rewiring of MAPK signaling, and ancestry-specific preferential expansion of B cell receptors. Peripheral blood mononuclear cells were obtained from individuals of African or European Ancestry (AA and EA, respectively) including 48 healthy controls, 59 sarcoidosis patients, and 28 systemic lupus erythematosus (SLE) patients. SLE samples were used as a disease control. Differential expression analysis highlighted many differentially expressed genes (DEGs) with almost 5x more in the AA sarcoidosis versus AA control group compared to the EA sarcoidosis versus EA control group. B cells had the most DEGs of all cell types and expression patterns were similar between ancestries, however, sarcoidosis had an opposite transcription pattern than SLE, demonstrating an alternative immune response to acute activation than that seen in a prototypical autoinflammatory disease. This trend was maintained when examining specialized B cell subsets, with the most pronounced effect in the AA sarcoidosis versus AA control comparison. Our results strongly support further investigation of the role of humoral immune response in sarcoidosis and the potential to highlight patient groups likely to benefit from existing B cell therapies.

Objective Sjögren’s disease (SjD) is a chronic exocrine disorder typified by inflammation and dryness, but also profound fatigue, suggesting a pathological basis in cellular bioenergetics. In healthy states, dysfunctional mitochondria are recycled by mitophagic processes; when impaired, poorly functioning mitochondria persist and produce inflammatory reactive oxygen species. Employing a case–control study, we tested our hypothesis that mitochondrial dysregulation in T cells is associated with fatigue in SjD.Methods We isolated pan T cells from peripheral blood mononuclear cells of 13 SjD and 4 non-Sjögren’s sicca (NSS) subjects, who completed several fatigue questionnaires, along with 8 healthy subjects. Using Seahorse, we analysed T cells for mitochondrial oxygen consumption rate (OCR) and extracellular acidification rate, which we assessed for correlation with fatigue measures. Using public microarray data available for 190 SjD and 32 healthy subjects, we identified a mitophagic transcriptional signature that stratified SjD patients into 5 discrete clusters. Comparisons between the SjD subjects in these clusters to healthy individuals identified differentially expressed transcripts, which we subjected to bioinformatic interrogation.Results Basal OCR, ATP-linked respiration, maximal respiration and reserve capacity were significantly lower in SjD and NSS subjects compared with healthy individuals, with no differences in non-mitochondrial respiration, basal glycolysis or glycolytic reserve. Scores related to a sleep questionnaire and Bowman’s Profile of Fatigue and Discomfort showed correlation with altered OCR in SjD. Subgroup differential expression analysis revealed dynamic transcriptional activity between mitophagy subgroups, expanding the number of differentially expressed transcripts tenfold.Conclusions Mitochondrial dysfunction and fatigue are significant problems in SjD warranting further investigation.

Spinocerebellar ataxia type 10 (SCA10) is an autosomal dominant (AD) neurodegenerative disorder prevalent in the Americas, particularly in Mexico. Clinical manifestations include progressive ataxia and epilepsy. However, it can exhibit wide phenotypic variability and even reduced penetrance. Because the diagnostic overlaps with other ataxias, molecular diagnosis is essential. This cross-sectional study conducted a retrospective review and analysis of 183 DNA samples from a laboratory registry of patients with ataxia who were suspected of having AD ataxia (n = 86; negative for ATXN1, ATXN2, ATXN3, ATXN7, TBP, and ATN1 genes) or sporadic ataxia (n = 97). Triplet repeat-primed PCR (TP-PCR) was performed to identify ATXN10 gene expansions. 19.6

Sjogren's disease (SjD) is a chronic autoimmune disorder characterized by inflammation of the exocrine glands, leading to dry mouth and dry eyes. This study investigates the role of interleukin-9 (IL-9) and T helper 9 (Th9) cells in the pathogenesis of SjD. We found that serum IL-9 levels were significantly elevated in SjD patients and correlated with clinical laboratory parameters, including autoantibody production. In a mouse model of SjD, IL-9 and Th9-associated cytokines were also elevated, and Th9 cells were enriched in the salivary glands. Our results suggest that IL-9 is produced by multiple cell types, including macrophages, CD4+ T cells, and NK cells, and that Th9 cells contribute to the development of SjD by promoting inflammation and autoantibody production. We also found that Th9 and Th17 polarization conditions increased Th2 and Th17 cells in SjD mice, indicating a shared epigenetic program that renders T cells permissive to multiple differentiation pathways. Anti-IL-9 treatment had a sex-dependent effect, reducing autoantibody production in male mice but worsening focal glandular infiltration in female mice. Our findings suggest that IL-9 plays a complex role in SjD pathobiology, contributing to both local immunoregulation and systemic autoantibody response. Overall, this study provides new insights into the role of IL-9 and Th9 cells in SjD and highlights the potential for therapeutic targeting of the IL-9/Th9 axis in the treatment of this disease. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This research was funded by the National Institutes of Health (NIH) and the National Institute of Dental and Craniofacial Research. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Institutional Review Board of each institution approved all procedures, and each participant provided written informed consent prior to entering the study. The study was conducted in accordance with current regulations protecting human subjects participating in research, HIPAA, and the Declaration of Helsinki. Studies were approved by the Institutional Review Board of the Oklahoma Medical Research Foundation I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present work are contained in the manuscript

OBJECTIVES:Diagnosis of Sjögren's disease (SjD) consists of clinical examinations that include invasive studies such as lower lip biopsies and blood collection to identify presence of serum autoantibodies. Salivary glands of patients with SjD are sites where antibody-secreting cells accumulate and secrete immunoglobulins. Many patients with dry manifestations who do not meet classification criteria are grouped as non-Sjögren's sicca (NSS) and are heavily understudied. We undertook this cross-sectional observational study to investigate the role of salivary autoantibodies as a diagnostic tool and determine presence of salivary autoantibodies in patients with NSS. METHODS:In this cross-sectional observational study, we screened whole unstimulated saliva from 446 subjects by direct enzyme-linked immunosorbent assays and capillary western blotting for anti-Ro60, anti-La, and rheumatoid factor (immunoglobulin (Ig)G and IgA) antibodies. All subjects were classified following the ACR/EULAR classification at the Oklahoma Medical Research Foundation Sjögren's Research Clinic. RESULTS:Patients with SjD were significantly more likely to have salivary antibodies compared with those with NSS and healthy control subjects. In this cohort, there were 88 subjects with NSS with seronegative profiles who had detectable salivary autoantibodies and objective measures of dryness. CONCLUSIONS:Of these 88 subjects with NSS, we identified 75 subjects that had positive objective examinations of dryness and could belong to an early-onset SjD group. Alternatively, these 75 subjects with NSS could belong to a distinct phenotype of SjD that will remain seronegative while being saliva positive for anti-Ro60. These data showed a relationship between ocular and oral dryness and the presence of salivary anti-Ro60 antibodies in subjects with NSS.

CD4+ T cells predominate lymphocytic foci found in the salivary glands (SGs) of Sjögren's disease (SjD) cases. Yet little is known about T cell receptor (TCR) repertoire features that distinguish cases from healthy controls (HCs), the relationship between SG and peripheral blood (PB) repertoires of cases, and antigens recognized by pathogenic T cell clones. We performed deep sequencing of bulk-sorted CD4+CD45RA- PB T cells from SjD cases and matched HCs, and single-cell TCR sequencing of the same T cell population from labial SG biopsies of these cases. We found that clonally expanded SG CD4+ T cells expressed complementarity-determining region 3 (CDR3) sequences that were also detected in multiple copies in the blood of the same individuals with SjD. SjD cases displayed a "private" and restricted PB TCR repertoire with reduced clonotype diversity. We identified SjD-associated TCR motifs with the same putative antigen specificity shared between SGs and PB of cases. Their abundances in PB correlated with reduced salivary flow, linking these T cells with pathogenic disease features. Finally, we discovered 2 Ro60 epitopes eliciting an HLA-restricted immune response from expanded SG T cell clones. The comprehensive characterization of SjD TCR repertoires enables the discovery of target antigens and therapeutic strategies.

Fine mapping and bioinformatic analysis of the DDX6-CXCR5 genetic risk association in Sjögren's Disease (SjD) and Systemic Lupus Erythematosus (SLE) identified five common SNPs with functional evidence in immune cell types: rs4938573, rs57494551, rs4938572, rs4936443, rs7117261. Functional interrogation of nuclear protein binding affinity, enhancer/promoter regulatory activity, and chromatin-chromatin interactions in immune, salivary gland epithelial, and kidney epithelial cells revealed cell type-specific allelic effects for all five SNPs that expanded regulation beyond effects on DDX6 and CXCR5 expression. Mapping the local chromatin regulatory network revealed several additional genes of interest, including lnc-PHLDB1-1. Collectively, functional characterization implicated the risk alleles of these SNPs as modulators of promoter and/or enhancer activities that regulate cell type-specific expression of DDX6, CXCR5, and lnc-PHLDB1-1, among others. Further, these findings emphasize the importance of exploring the functional significance of SNPs in the context of complex chromatin architecture in disease-relevant cell types and tissues.

Background: Sjögren's disease (SjD) is a complex systemic autoimmune disease with substantial morbidity and 21 known genetic associations. The International Sjögren's Genetics Network (SGENE) is a growing international collaboration focused on understanding how genetic variants influence SjD pathology. As sample sizes increase, we are focusing our efforts on the analyses of clinical subsets, which few studies have done. Objectives: Our genome-wide association study (GWAS) aimed to identify additional risk loci of genome-wide significance (GWS, p<5E-08; suggestive, p<5x10E-5) in European-derived subsets of SjD. Methods: This study was conducted with IRB/EC approvals. All SjD patients met the 2002 AECG criteria for SjD. A total of 5058 cases and 25943 controls were genotyped on GWAS arrays. After QC, 4855 cases and 25408 controls were included in the analyses. Logistic regression was calculated, adjusting for ancestry using the first 4 principal components to identify SjD-associated SNPs. Cases were split into Ro/SSA+ (n=2898) and Ro/SSA- (n=1313), and analyzed vs. each other, controls, and all-SjD. Results: We observed many differences in the genomic architecture of Ro/SSA- compared to Ro/SSA+ and all SjD (Figure 1a,b), most notably, a complete loss of the significance of the association with MHC on chromosome 6 in the Ro/SSA- cases(Figure 1b). The Ro/SSA+ subjects had a much stronger HLA association with OR ≈ 4 (Figure 1a), while the overall SjD showed OR ≈ 3. While none of the associations observed in the Ro/SSA- population reached GWS, 8 regions (near PLXNA2, PCDH7, IRF5-TNPO3, DLD, LOC100134229, JAK3, LOC643529, and TMTC1) show suggestive associations (Figure. 1a). Of these, only two, IRF5-TNPO3 and LOC643529, are also suggestive in the Ro/SSA+ subset. However, while the Ro/SSA+ have both the IRF5 promoter effect and the extended haplotype through TNPO3, the Ro/SSA- lack the IRF5 promoter effect. Interestingly, previous studies have shown that lupus and systemic sclerosis have both haplotypes while primary biliary cholangitis only has the haplotype extending into TNPO3, similar to Ro/SSA- SjD [1]. When comparing Ro/SSA- to the all-SjD dataset, PLXNA2 and LOC100134229 showed no association; PCDH7, DLD, and TMTC1 showed some association but did not reach suggestive levels; and LOC643529, IRF5-TNPO3, and JAK3 surpassed the suggestive threshold, the latter two nearing or surpassing GWS. Two of the novel suggestive associations in Ro/SSA- are particularly intriguing. PLXNA2 is a member of a semaphorin co-receptor family that mediates repulsive effects on axon pathfinding during nervous system development; interestingly, Ro/SSA- SjD has a higher frequency of neurological involvement. JAK3 is a member of the Janus kinase (JAK) family of tyrosine kinases involved in cytokine receptor-mediated intracellular signal transduction; it is predominantly expressed in immune cells. Mutations in this gene are associated with autosomal severe combined immunodeficiency disease. Novel drugs target the JAK-STAT pathways, making this finding markedly relevant. Conclusion: Our findings highlight the relevance of expanding genetic studies to specific subphenotypes of the disease. While we continue to increase our GWAS sample size and explore other subphenotypes, more work is needed to increase the power of these studies to determine if the suggestive regions will surpass the GWS threshold. REFERENCES: [1] Kottyan LC, et al. Hum Mol Genet. 2015 Jan 15;24(2):582-96. Acknowledgements: NIH/NIAMS R01 AR073855, P50 AR060804; NIH/NIDCR U01DE028891; Sjögren's Foundation; Jerome L. Greene Foundation. Disclosure of Interests: Astrid Rasmussen: None declared, Marcin Radziszewski: None declared, Bhuwan Khatri: None declared, Kandice L Tessneer: None declared, Elena Pontarini: None declared, Michele Bombardieri: None declared, Maureen Rischmueller: None declared, Marie Wahren-Herlenius: None declared, Marika Kvarnström: None declared, Torsten Witte: None declared, Hendrika Bootsma: None declared, Gwenny M. Verstappen: None declared, Frans G.M. Kroese: None declared, Arjan Vissink: None declared, Sarah Pringle: None declared, Athanasios Tzioufas: None declared, Clio Mavragani: None declared, Alan Baer Received consulting fees from Bristol Myers Squibb (BMS) and iCell Gene Therapeutics., Marta Alarcon-Riquelme: None declared, Javier Martin: None declared, Xavier Mariette: None declared, Gaetane Nocturne: None declared, Jacques-Olivier Pers: None declared, Jacques-Eric Gottenberg: None declared, Wan-Fai Ng I have consulted for Novartis, BMS, Janssen, Sanofi, Abbvie, IQVIA, Argenx, Resolve Therapeutics., Caroline Shiboski: None declared, Kimberly E Taylor: None declared, Lindsey Criswell: None declared, Blake M Warner: None declared, A Darise Farris Grant/research support from Johnson and Johnson Innovative Medicine (formerly Janssen; ended 12/31/2023)., Judith A. James: None declared, R Hal Scofield Received consulting fees from Johnson and Johnson Innovative Medicine (formerly Janssen) and Merk Pharmaceuticals., Joel M Guthridge: None declared, Daniel J Wallace: None declared, Swamy Venuturupali: None declared, Michael T Brennan: None declared, Juliana Imgenberg-Kreuz: None declared, Lars Ronnblom: None declared, Eva Baecklund: None declared, Maija-leena Eloranta: None declared, Lara A Aqrawi: None declared, Øyvind Palm: None declared, Johan G Brun: None declared, Daniel Hammenfors: None declared, Malin V Jonsson: None declared, Silke Appel: None declared, Sara Magnusson Bucher: None declared, Helena Forsblad-d'Elia: None declared, Thomas Mandl Employee of UCB., Per Eriksson: None declared, Gunnel Nordmark: None declared, Christopher J Lessard Grant/research support from Johnson and Johnson Innovative Medicine (formerly Janssen; ended 12/31/2023).

Spinocerebellar ataxia type 10 (SCA10) is a rare autosomal dominant ataxia caused by a large expansion of the (ATTCT)n repeat in ATXN10. SCA10 was described in Native American and Asian individuals which prompted a search for an expanded haplotype to confirm a common ancestral origin for the expansion event. All patients with SCA10 expansions in our cohort share a single haplotype defined at the 5'-end by the minor allele of rs41524547, located ~35 kb upstream of the SCA10 expansion. Intriguingly, rs41524547 is located within the miRNA gene, MIR4762, within its DROSHA cleavage site and just outside the seed sequence for mir4792-5p. The world-wide frequency of rs41524547-G is less than 5% and found almost exclusively in the Americas and East Asia-a geographic distribution that mirrors reported SCA10 cases. We identified rs41524547-G(+) DNA from the 1000 Genomes/International Genome Sample Resource and our own general population samples and identified SCA10 repeat expansions in up to 25% of these samples. The reduced penetrance of these SCA10 expansions may be explained by a young (pre-onset) age at sample collection, a small repeat size, purity of repeat units, or the disruption of miR4762-5p function. We conclude that rs41524547-G is the most robust at-risk SNP allele for SCA10, is useful for screening of SCA10 expansions in population genetics studies and provides the most compelling evidence to date for a single, prehistoric origin of SCA10 expansions sometime prior to or during the migration of individuals across the Bering Land Bridge into the Americas.

Background: Neurological manifestations can occur in up to half of patients with Sjögren disease (SjD) and the peripheral nervous system (PNS) is the most commonly involved (5-21%). Objectives: To analyze the frequency and phenotypic expression of PNS involvement at the time of SjD diagnosis Methods: The Big Data Project Consortium is an international, multicenter registry created in 2014. Baseline clinical information from leading centers on clinical research in SjD of the five continents was collected as a first step. The centers share a harmonized data architecture and conduct cooperative online efforts to refine collected data under the coordination of a big data statistical team. The inclusion criteria were the fulfillment of the 2002 or 2016 classification criteria. Results: By December 2023, the participant centers had included 16'703 patients from 28 countries (15'602 women, mean age at diagnosis of 51.66 years). PNS involvement at diagnosis, defined according to the ESSDAI classification, was reported in 869 (5.2%) patients. Among them, 518 (60%) showed mild active PNS involvement (pure sensory axonal polyneuropathy, V neuralgia, or proven small fibre neuropathy), 264 (30%) showed moderate involvement (axonal sensory–moto neuropathy, cryoglobulinemic pure sensory neuropathy, mild/moderate ganglionopathy, mild chronic inflammatory demyelinating polyneuropathy -CIDP-, or other cranial nerve involvements), and 87 (10%) showed highly active PNS involvement (severe motor axonal neuropathy, mononeuritis multiplex, severe ataxia due to ganglionopathy, or severe CIDP). Univariate analysis showed that patients with PNS involvement were more frequently men, diagnosed at an older age, white, had a higher frequency of activity in all the 12 ESSDAI domains and more commonly hypocomplementemia and cryoglobulinemia (all P-values <0.001). The multivariate logistic regression model adjusted for age, sex, ethnicity and the ESSDAI domains showed that systemic activity in the constitutional (OR = 1.95; 95% CI, 1.43–2.65), articular (OR = 1.35; 95% CI, 1.06–1.73), renal (OR = 1.92; 95% CI, 1.25–2.96), muscular (OR = 1.89; 95% CI, 1.11–3.24) and CNS (OR = 5.37; 95% CI, 3.18–9.06) ESSDAI domains, as well as low C3 (OR = 1.44; 95% CI, 1.05–1.98) and low C4 (OR = 1.74; 95% CI, 1.27–2.39), were independently associated with a diagnosis of PNS involvement at the time of diagnosis of SjD. Conclusion: Around 5% of patients had PNS involvement at the time of diagnosis of SjD. Patients with PNS involvement showed higher systemic activity in multiple domains (1.3-2 times higher frequency of constitutional, joint, renal, and muscular involvement), especially concerning concomitant CNS involvement (5-fold higher frequency). Hypocomplementemia was the key immunological marker independently associated with PNS involvement. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.