CD8+ tissue-resident memory T cells are expanded in primary Sjögren's disease and can be therapeutically targeted by CD103 blockade.

OBJECTIVE: Tissue-resident memory cells (Trm) are a subset of T cells residing persistently and long-term within specific tissues that contribute to persistent inflammation and tissue damage. We characterised the phenotype and function of Trm and the role of CD103 in primary Sjogren's syndrome (pSS). METHODS: In both pSS and non-pSS sicca syndrome patients, we examined Trm frequency, cytokine production in salivary glands (SG) and peripheral blood (PB). We also analysed Trm-related gene expression in SG biopsies through bulk and single-cell RNA sequencing (scRNAseq). Additionally, we investigated Trm properties in an immunisation-induced animal model of pSS (experimental SS, ESS) mouse model and assessed the effects of Trm inhibition via intraglandular anti-CD103 monoclonal antibody administration. RESULTS: Transcriptomic pSS SG showed an upregulation of genes associated with tissue recruitment and long-term survival of Trm cells, confirmed by a higher frequency of CD8+CD103+CD69+ cells in pSS SG, compared with non-specific sialadenitis (nSS). In SG, CD8+ CD103+ Trm contributed to the secretion of granzyme-B and interferon-γ, CD8+ Trm cells were localised within inflammatory infiltrates, where PD1+CD8+ T cells were also increased compared with nSS and MALT lymphoma. scRNAseq of PB and pSS SG T cells confirmed expression of CD69, ITGAE, GZMB, GZMK and HLA-DRB1 among CD3+CD8+ SG T cells. In the SG of ESS, CD8+CD69+CD103+ Trm producing Granzyme B progressively expanded. However, intraglandular blockade of CD103 in ESS reduced Trm, reduced glandular damage and improved salivary flow. CONCLUSIONS: CD103+CD8+Trm cells are expanded in the SG of pSS and ESS, participate in tissue inflammation and can be therapeutically targeted.

Primary Sjögren's syndrome in South Australia.

OBJECTIVES: To describe clinical and serological characteristics of a South Australian primary Sjögren's syndrome (pSS) cohort. METHODS: The South Australian Sjögren's Syndrome Research Clinic and Database is a clinical cohort of patients with pSS at a single site. Baseline clinical and laboratory data from 172 patients were retrospectively examined to determine their prevalence and clinical associations. Results were compared to findings from 10,500 patients from The Big Data Sjogren Project Consortium; an international, multicentre registry established in 2014, which included the South Australian data. RESULTS: Of 172 South Australian patients with pSS, 90.1% were female with a mean age at diagnosis of 57 years. Ocular and oral sicca symptoms were common, affecting 97.1% and 99.4% respectively. Anti-Ro ± La positivity was detected in 82.6%, ANA positivity in 77%, and in 9% of patients both ANA and ENA were negative. Mean ESSDAI was 6.8 at baseline, slightly higher than the international cohort at 6.1; the most commonly positive domains being biological, articular and glandular. Pulmonary manifestations represented the most significant morbidity over time. Lymphoma was recorded in 5.2% of patients and congenital heart block in 4 offspring of 52 patients with longitudinal follow-up (7.7%), although incomplete data likely resulted in underestimation of both. CONCLUSIONS: Despite the relatively small sample size of the South Australian cohort, clinical and serological characteristics correspond closely with international descriptions.

Immune activation in patients with irritable bowel syndrome.

BACKGROUND AND AIMS: We set out to test the hypothesis that irritable bowel syndrome (IBS) is characterized by an augmented cellular immune response with enhanced production of proinflammatory cytokines. We further aimed to explore whether symptoms and psychiatric comorbidity in IBS are linked to the release of proinflammatory cytokines. METHODS: We characterized basal and Escherichia coli lipopolysaccharide (LPS)-induced cytokine production in peripheral blood mononuclear cells (PBMCs) from 55 IBS patients (18 mixed-, 17 constipation-, 20 diarrhea-predominant) and 36 healthy controls (HCs). PBMCs were isolated by density gradient centrifugation and cultured for 24 hours with or without (1 ng/mL) LPS. Cytokine production (tumor necrosis factor [TNF]-alpha, interleukin [IL]-1beta, and IL-6) was measured by enzyme-linked immunosorbent assay. Abdominal symptoms and psychiatric comorbidities were assessed by using the validated Bowel Disease Questionnaire and the Hospital Anxiety and Depression Scale. RESULTS: IBS patients showed significantly (P < .017) higher baseline TNF-alpha, IL-1beta, IL-6, and LPS-induced IL-6 levels compared with HCs. Analyzing IBS subgroups, all cytokine levels were significantly (P < .05) higher in diarrhea-predominant IBS (D-IBS) patients, whereas constipation-predominant IBS patients showed increased LPS-induced IL-1beta levels compared with HCs. Baseline TNF-alpha and LPS-induced TNF-alpha and IL-6 levels were significantly higher in patients reporting more than 3 bowel movements per day, urgency, watery stools, and pain associated with diarrhea compared with patients without these symptoms (all P < .05). LPS-induced TNF-alpha production was associated significantly (r = 0.59, P < .001) with anxiety in patients with IBS. CONCLUSIONS: Patients with D-IBS display enhanced proinflammatory cytokine release, and this may be associated with symptoms and anxiety.

Influence of CTLA4 haplotypes on susceptibility and some extraglandular manifestations in primary Sjögren's syndrome.

OBJECTIVE: Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) is a key negative regulator of the T cell immune response, and the CTLA4 gene is highly polymorphic. Many positive associations between CTLA4 single-nucleotide polymorphisms (SNPs) and various autoimmune diseases have been identified. Two CTLA4 SNPs that are important relative to genetic susceptibility in human autoimmune diseases are the +49GA polymorphism in exon 1 and the CT60A/G polymorphism in the 3'-untranslated region. Using these 2 polymorphisms as markers, we investigated possible genetic associations of CTLA4 in Australian patients with primary Sjögren's syndrome. METHODS: One hundred eleven Australian Caucasian patients with primary SS and 156 population-based controls were genotyped for CTLA4 by polymerase chain reaction-restriction fragment length polymorphism methods, using the restriction enzymes BseXI (+49G/A) and HpyCh4 IV (CT60). RESULTS: The CT60 and +49G/A SNPs were in strong linkage disequilibrium, and only 3 haplotypes were observed. Significant differences in the haplotype frequencies between patients with primary SS and controls (P = 0.032) were observed, with susceptibility to primary SS associated with both the +49A;CT60A haplotype and the +49A;CT60G haplotype, whereas the +49G;CT60G haplotype was protective against primary SS. The +49A;CT60G haplotype association was predominantly with Ro/La autoantibody-positive primary SS, and the dose of this haplotype influenced the severity of daytime sleepiness (P = 0.036). The +49A;CT60A haplotype appeared to be protective against the development of Raynaud's phenomenon in patients with primary SS (odds ratio 0.49, 95% confidence interval 0.27-0.91). CONCLUSION: The CTLA4 +49G/A and CT60 haplotypes are associated with susceptibility to primary SS and with some extraglandular manifestations of the disease.

Increased severity of lower urinary tract symptoms and daytime somnolence in primary Sjögren's syndrome.

OBJECTIVE: Functional antimuscarinic receptor autoantibodies have recently been described in both primary and secondary Sjögren's syndrome (SS) in a mouse bladder contraction assay. Most patients with these antibodies complained of severe lower urinary tract disturbances, which are not a recognized feature of SS. We compared the severity of self-reported urological symptoms, daytime somnolence, and fatigue between a cohort of patients with primary SS and controls with osteoarthritis (OA). METHODS: Female patients were recruited from rheumatology outpatient clinics at 2 hospitals. The American Urological Symptom Index (AUA-7), Epworth Sleepiness Scale, and FACIT-F fatigue self-administered instruments were employed. Results were obtained for 76 patients with primary SS and 43 controls (response rates 85% and 67%, respectively). The patient groups were matched for parity, hormone replacement and diuretic therapy, and number of bladder operations and urinary tract infections, although OA patients were slightly older. RESULTS: AUA-7 urological symptoms were more severe in patients with primary SS compared to OA controls (p = 0.039). Severe urological symptoms were reported by 61% of primary SS patients compared with 40% of OA controls. This difference was predominantly attributable to bladder irritability associated with urgency (p = 0.015) and not nocturia (p = 0.85). Epworth Sleepiness Scale scores were also more severe in primary SS patients compared to OA controls (p = 0.02), independent of nocturia. The FACIT-F fatigue severity scores were not significantly different between patient groups (p = 0.14). CONCLUSION: Urological symptoms and daytime somnolence may be previously unrecognized symptoms of primary SS. These symptoms are consistent with functional disturbances of muscarinic receptors, possibly mediated by muscarinic receptor autoantibodies.