EULAR Sjögren's syndrome disease activity index (ESSDAI): a user guide

The EULAR Sjögren's syndrome (SS) disease activity index (ESSDAI) is a systemic disease activity index that was designed to measure disease activity in patients with primary SS. With the growing use of the ESSDAI, some domains appear to be more challenging to rate than others. The ESSDAI is now in use as a gold standard to measure disease activity in clinical studies, and as an outcome measure, even a primary outcome measure, in current randomised clinical trials. Therefore, ensuring an accurate and reproducible rating of each domain, by providing a more detailed definition of each domain, has emerged as an urgent need. The purpose of the present article is to provide a user guide for the ESSDAI. This guide provides definitions and precisions on the rating of each domain. It also includes some minor improvement of the score to integrate advance in knowledge of disease manifestations. This user guide may help clinicians to use the ESSDAI, and increase the reliability of rating and consequently of the ability to detect true changes over time. This better appraisal of ESSDAI items, along with the recent definition of disease activity levels and minimal clinically important change, will improve the assessment of patients with primary SS and facilitate the demonstration of effectiveness of treatment for patients with primary SS.

Association of hippocampal atrophy with cerebrospinal fluid antibodies against the NR2 subtype of the N-methyl-D-aspartate receptor in patients with systemic lupus erythematosus and patients with primary Sjögren's syndrome

OBJECTIVE

Cognitive dysfunction is common in both systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (SS). Antibodies against the NR2 subtype of the N-methyl-D-aspartate receptor (anti-NR2 antibodies) cause hippocampal atrophy and cognitive impairment in mice and have been associated with memory impairment in both patients with SLE and patients with primary SS. In addition, a reduced volume of hippocampal gray matter has been demonstrated in both SLE and primary SS. This study was undertaken to investigate whether there is a connection between the presence of anti-NR2 antibodies and hippocampal atrophy in human diseases.

METHODS

Fifty patients with SLE and 50 patients with primary SS underwent clinical examination and cerebral magnetic resonance imaging. Anti-NR2 antibodies in cerebrospinal fluid (CSF) were measured, and hippocampal gray matter volumes were compared between patients who were positive for and those who were negative for anti-NR2 antibodies.

RESULTS

Patients with anti-NR2 antibodies in CSF had less hippocampal gray matter than patients without these antibodies. No other differences regarding gray matter volumes in other parts of the brain were identified.

CONCLUSION

The present findings indicate that anti-NR2 antibodies in patients with SLE and primary SS cause neuronal death manifested as reduced hippocampal gray matter, as has been previously demonstrated in mice with autoimmune disease.

Primary Sjögren's Syndrome Associated Neuropathy

Primary Sjögren's syndrome (PSS) mainly affects exocrine glands and is clinically characterized by keratoconjunctivitis sicca and xerostomia. Among several possible extraglandular manifestations, involvement of the peripheral nervous system may occur with reported frequencies from 10% to 60%. Peripheral nerve manifestations constitute sensory neuropathy, including sensory ganglioneuronopathy, sensorimotor, including polyradiculoneuropathy and demyelinating neuropathy, motor neuropathy, multiple mononeuropathy, trigeminal and other cranial neuropathies, autonomic neuropathy, and mixed patterns of neuropathy. Knowledge of the neurological manifestations of PSS is hampered by evolving classification criteria of PSS over the years, and by use of highly selected patient populations on the basis of a primary neurological diagnosis. Sural nerve biopsy may show vascular or perivascular inflammation of small epineurial vessels (both arterioles and venules) and in some cases necrotizing vasculitis. Loss of myelinated nerve fibers is common and loss of small diameter nerve fibers occurs. Pathology in cases of sensory ganglioneuronopathy consists of loss of neuronal cell bodies and infiltration of T cells. Peripheral neuropathy in PSS often is refractory to treatment although newer biological agents may provide more effective treatment options. Current treatment strategies used in autoimmune neuropathies may be tried depending upon characteristics of the neuropathy and results obtained by a thorough clinical and laboratory investigation.

Evaluation of Germinal Center-like Structures and B Cell Clonality in Patients with Primary Sjögren Syndrome with and without Lymphoma

Objective.

Germinal center (GC)-like structures have previously been observed in minor salivary glands (MSG) of patients with primary Sjögren syndrome (pSS). The aim of our study was to explore the prevalence and features of GC-like structures and B cell clonality in patients with pSS with and without lymphoma.

Methods.

Based on a nationwide survey in Norway, we included 21 patients with pSS and with a concomitant lymphoma from whom MSG and/or lymphoma biopsies were available. Tonsil biopsies and MSG from 28 patients with pSS without lymphoma were used as controls. The presence of GC-like structures was investigated with H&E staining and double staining for CD21/IgD and CD38/IgD. B cell clonality in MSG and tumors were investigated with analysis of immunoglobulin gene rearrangements.

Results.

H&E labeling of MSG revealed GC-like structures in 17/40 (43%) of the patients: 4/12 (33%) with and 13/28 (46%) without lymphoma. Staining for CD21/CD38/IgD demonstrated CD21+ networks in 27/40 (68%) of the patients. CD21+/CD38– infiltrates were seen in 25/40 (63%) of the patients, and 16 of these were IgD+ within the infiltrate. Five percent (2/40) of the patients presented with CD21+/CD38+ infiltrates resembling tonsillar GC. Monoclonal B cell infiltration in MSG was present in 5/12 patients (42%) with and 5/28 patients (18%) without lymphoma (p = 0.12). In 2/10 (20%) of cases where both MSG and lymphoma biopsies were available, identical clonal rearrangements were detected.

Conclusion.

GC-like structures seen in H&E-stained MSG may represent various subtypes of CD21+ infiltrates. We were unable to detect a clear association between cellular infiltrates, B cell clonality, and lymphoma development.

The IRF5-TNPO3 association with systemic lupus erythematosus has two components that other autoimmune disorders variably share

Exploiting genotyping, DNA sequencing, imputation and trans-ancestral mapping, we used Bayesian and frequentist approaches to model the IRF5-TNPO3 locus association, now implicated in two immunotherapies and seven autoimmune diseases. Specifically, in systemic lupus erythematosus (SLE), we resolved separate associations in the IRF5 promoter (all ancestries) and with an extended European haplotype. We captured 3230 IRF5-TNPO3 high-quality, common variants across 5 ethnicities in 8395 SLE cases and 7367 controls. The genetic effect from the IRF5 promoter can be explained by any one of four variants in 5.7 kb (P-valuemeta = 6 × 10(-49); OR = 1.38-1.97). The second genetic effect spanned an 85.5-kb, 24-variant haplotype that included the genes IRF5 and TNPO3 (P-valuesEU = 10(-27)-10(-32), OR = 1.7-1.81). Many variants at the IRF5 locus with previously assigned biological function are not members of either final credible set of potential causal variants identified herein. In addition to the known biologically functional variants, we demonstrated that the risk allele of rs4728142, a variant in the promoter among the lowest frequentist probability and highest Bayesian posterior probability, was correlated with IRF5 expression and differentially binds the transcription factor ZBTB3. Our analytical strategy provides a novel framework for future studies aimed at dissecting etiological genetic effects. Finally, both SLE elements of the statistical model appear to operate in Sjögren's syndrome and systemic sclerosis whereas only the IRF5-TNPO3 gene-spanning haplotype is associated with primary biliary cirrhosis, demonstrating the nuance of similarity and difference in autoimmune disease risk mechanisms at IRF5-TNPO3.

Loss of cerebral white matter in primary Sjögren's syndrome: a controlled volumetric magnetic resonance imaging study

BACKGROUND AND PURPOSE

Although brain involvement is common in primary Sjögren's syndrome (pSS), results from cerebral imaging studies are inconsistent. This study aimed to perform both voxel-wise and global brain volume analyses in a nearly population-based pSS cohort to explore whether the patients displayed any focal or diffuse volume differences compared with healthy subjects.

METHODS

Global grey matter (GM) and white matter (WM) volumes were measured and compared in 60 patients with pSS and 60 age- and gender-matched healthy subjects. Regression models were constructed with potential explanatory variables for GM and WM volumes. In the same groups, voxel-wise morphometric analyses were performed.

RESULTS

In analyses of global GM and WM, the patients had lower WM volumes than healthy subjects (540 ± 63 cm(3) vs. 564 ± 56 cm(3), P = 0.02), but no differences in GM. Voxel-wise analyses displayed no localized areas of GM or WM volume differences between pSS patients and healthy subjects.

CONCLUSION

Individuals with pSS have a diffuse reduction of cerebral WM but no localized loss of WM or GM. This indicates a general deleterious effect on WM due to pSS itself.

X chromosome dose and sex bias in autoimmune diseases: increased 47,XXX in systemic lupus erythematosus and Sjögren’s syndrome (BA4P.211)

Mechanism for female predominance in autoimmunity is unknown. We suspected an X chromosome dose effect and predicted if so, triple X (47,XXX, 1 in ~1,000 live female births) would be increased in female predominant diseases (systemic lupus erythematosus [SLE], primary Sjögren’s syndrome [SS], primary biliary cirrhosis [PBC] and rheumatoid arthritis [RA])compared to diseases without female predominance (sarcoidosis, granulomatosis with polyangiitis [GPA]) and healthy controls. We used single nucleotide polymorphism (SNP) arrays to identify 47,XXX and fluorescent in situ hybridization, or q-PCR to confirm when possible. 47,XXX was found in 7 of 2,948 SLE and 3 of 1,053 SS female patients, but in none of the 4,822 female controls (OR≥21.31, 95% CI: 2.36-∞, p=0.001 and OR≥22.95, 95% CI: 1.89-∞, p=0.006, respectively). One 47,XXX was present for every ~421 SLE women and ~351 SS women. In addition, we identified one 47,XXX from each of 1,159 women with PBC and 943 with sarcoidosis. No 47,XXX was identified among 453 women with RA or 247 with GPA. In conclusion, 47,XXX was present in excess among SLE and SS subjects as predicted by X chromosome dose effect. These estimated prevalence of SLE and SS with 47,XXX being respectively ~2.4 and ~2.8 times higher than in women with 46,XX and ~24 and ~39 times higher than in men with 46,XY. There was no increase of 47,XXX is other female-biased diseases, suggesting multiple pathways to such a bias in autoimmunity.

NCR3/NKp30 contributes to pathogenesis in primary Sjogren's syndrome

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease characterized by a lymphocytic exocrinopathy. However, patients often have evidence of systemic autoimmunity, and they are at markedly increased risk for the development of non- Hodgkin's lymphoma. Similar to other autoimmune disorders, a strong interferon (IFN) signature is present among subsets of pSS patients, although the precise etiology remains uncertain. NCR3/NKp30 is a natural killer (NK)-specific activating receptor regulating the cross talk between NK and dendritic cells and type II IFN secretion. We performed a case-control study of genetic polymorphisms of the NCR3/NKp30 gene and found that rs11575837 (G>A) residing in the promoter was associated with reduced gene transcription and function as well as protection to pSS. We also demonstrated that circulating levels of NCR3/NKp30 were significantly increased among pSS patients compared with controls and correlated with higher NCR3/NKp30 but not CD16-dependent IFN-γ secretion by NK cells. Excess accumulation of NK cells in minor salivary glands correlated with the severity of the exocrinopathy. B7H6, the ligand of NKp30, was expressed by salivary epithelial cells. These findings suggest that NK cells may promote an NKp30-dependent inflammatory state in salivary glands and that blockade of the B7H6/NKp30 axis could be clinically relevant in pSS.

Association of genes in the NF-κB pathway with antibody-positive primary Sjögren's syndrome

Primary Sjögren's syndrome (SS) is a systemic autoimmune inflammatory disease characterized by focal lymphocytic infiltrates in the lachrymal and salivary glands and autoantibodies against the SSA/Ro and SSB/La antigens. Experimental studies have shown an activation of NF-κB in primary SS. NF-κB activation results in inflammation and autoimmunity and is regulated by inhibitory and activating proteins. Genetic studies have shown an association between multiple autoimmune diseases and TNFAIP3 (A20) and TNIP1 (ABIN1), both repressors of NF-κB and of IKBKE (IKKε), which is an NF-κB activator. The aim of this study was to analyse single nucleotide polymorphisms (SNPs) in the IKBKE, NFKB1, TNIP1 and TNFAIP3 genes for association with primary SS. A total of 12 SNPs were genotyped in 1105 patients from Scandinavia (Sweden and Norway, n = 684) and the UK (n = 421) and 4460 controls (Scandinavia, n = 1662, UK, n = 2798). When patients were stratified for the presence of anti-SSA and/or anti-SSB antibodies (n = 868), case-control meta-analysis found an association between antibody-positive primary SS and two SNPs in TNIP1 (P = 3.4 × 10(-5) , OR = 1.33, 95%CI: 1.16-1.52 for rs3792783 and P = 1.3 × 10(-3) , OR = 1.21, 95%CI: 1.08-1.36 for rs7708392). A TNIP1 risk haplotype was associated with antibody-positive primary SS (P = 5.7 × 10(-3) , OR = 1.47, 95%CI: 1.12-1.92). There were no significant associations with IKBKE, NFKB1 or TNFAIP3 in the meta-analysis of the Scandinavian and UK cohorts. We conclude that polymorphisms in TNIP1 are associated with antibody-positive primary SS.

Variants at multiple loci implicated in both innate and adaptive immune responses are associated with Sjögren's syndrome

Sjögren’s syndrome is a common autoimmune disease (~0.7% of European Americans) typically presenting as keratoconjunctivitis sicca and xerostomia. In addition to strong association within the HLA region at 6p21 (P_meta=7.65×10⁻¹¹⁴), we establish associations with IRF5-TNPO3 (P_meta=2.73×10⁻¹⁹), STAT4 (P_meta=6.80×10⁻¹⁵), IL12A (P_meta =1.17×10⁻¹⁰), FAM167A-BLK (P_meta=4.97×10⁻¹⁰), DDX6-CXCR5 (P_meta=1.10×10⁻⁸), and TNIP1 (P_meta=3.30×10⁻⁸). Suggestive associations with P_meta<5×10⁻⁵ were observed with 29 regions including TNFAIP3, PTTG1, PRDM1, DGKQ, FCGR2A, IRAK1BP1, ITSN2, and PHIP amongst others. These results highlight the importance of genes involved in both innate and adaptive immunity in Sjögren’s syndrome.

A possible genetic association with chronic fatigue in primary Sjögren's syndrome: a candidate gene study

Fatigue is prevalent and disabling in primary Sjögren's syndrome (pSS). Results from studies in chronic fatigue syndrome (CFS) indicate that genetic variation may influence fatigue. The aim of this study was to investigate single nucleotide polymorphism (SNP) variations in pSS patients with high and low fatigue. A panel of 85 SNPs in 12 genes was selected based on previous studies in CFS. A total of 207 pSS patients and 376 healthy controls were genotyped. One-hundred and ninety-three patients and 70 SNPs in 11 genes were available for analysis after quality control. Patients were dichotomized based on fatigue visual analogue scale (VAS) scores, with VAS <50 denominated "low fatigue" (n = 53) and VAS ≥50 denominated "high fatigue" (n = 140). We detected signals of association with pSS for one SNP in SLC25A40 (unadjusted p = 0.007) and two SNPs in PKN1 (both p = 0.03) in our pSS case versus control analysis. The association with SLC25A40 was stronger when only pSS high fatigue patients were analysed versus controls (p = 0.002). One SNP in PKN1 displayed an association in the case-only analysis of pSS high fatigue versus pSS low fatigue (p = 0.005). This candidate gene study in pSS did reveal a trend for associations between genetic variation in candidate genes and fatigue. The results will need to be replicated. More research on genetic associations with fatigue is warranted, and future trials should include larger cohorts and multicentre collaborations with sharing of genetic material to increase the statistical power.

A salmon peptide diet alleviates experimental colitis as compared with fish oil

Fish oil (FO) has been shown to have anti-inflammatory properties in animal models of inflammatory bowel disease, but how fish peptides (FP) influence intestinal inflammation has been less studied. Male Wistar rats, divided into five groups, were included in a 4-week dietary intervention study. Of the groups, four were exposed in the fourth week to 5 % dextran sulfate sodium (DSS) to induce colitis, while one group was unexposed. The diets were: (1) control, (2) control + DSS, (3) FO (5 %) + DSS, (4) FP (3·5 %) + DSS, (5) FO + FP + DSS. Following DSS intake, weight and disease activity index (DAI) were assessed, and histological combined score (HCS), selected colonic PG, cytokines, oxidative damage markers and mRNA levels were measured. FP reduced HCS, tended to lower DAI (P = 0·07) and reduced keratinocyte chemoattractant/growth-regulated oncogene levels, as compared with the FO diet. FP also reduced mRNA levels of Il-6 and Cxcl1, although not significantly. FO intake increased the DAI as compared with DSS alone. PGE3 levels increased after the FO diet, and even more following FO + FP intake. The FP diet seems to have a protective effect in DSS-induced colitis as compared with FO. A number of beneficial, but non-significant, changes also occurred after FP v. DSS. A combined FO + FP diet may influence PG synthesis, as PGE3 levels were higher after the combined diet than after FO alone.