Genetic and clinical basis for two distinct subtypes of primary Sjögren's syndrome

OBJECTIVES

Clinical presentation of primary Sjögren's syndrome (pSS) varies considerably. A shortage of evidence-based objective markers hinders efficient drug development and most clinical trials have failed to reach primary endpoints.

METHODS

We performed a multicentre study to identify patient subgroups based on clinical, immunological and genetic features. Targeted DNA sequencing of 1853 autoimmune-related loci was performed. After quality control, 918 patients with pSS, 1264 controls and 107 045 single nucleotide variants remained for analysis. Replication was performed in 177 patients with pSS and 7672 controls.

RESULTS

We found strong signals of association with pSS in the HLA region. Principal component analysis of clinical data distinguished two patient subgroups defined by the presence of SSA/SSB antibodies. We observed an unprecedented high risk of pSS for an association in the HLA-DQA1 locus of odds ratio 6.10 (95% CI: 4.93, 7.54, P=2.2×10-62) in the SSA/SSB-positive subgroup, while absent in the antibody negative group. Three independent signals within the MHC were observed. The two most significant variants in MHC class I and II respectively, identified patients with a higher risk of hypergammaglobulinaemia, leukopenia, anaemia, purpura, major salivary gland swelling and lymphadenopathy. Replication confirmed the association with both MHC class I and II signals confined to SSA/SSB antibody positive pSS.

CONCLUSION

Two subgroups of patients with pSS with distinct clinical manifestations can be defined by the presence or absence of SSA/SSB antibodies and genetic markers in the HLA locus. These subgroups should be considered in clinical follow-up, drug development and trial outcomes, for the benefit of both subgroups.

Neurofilament light is a biomarker of brain involvement in lupus and primary Sjögren's syndrome

Background

To test the hypothesis that neurofilament light (NfL) in CSF is a biomarker of CNS involvement in patients with systemic lupus erythematosus (SLE) and primary Sjögren’s syndrome (pSS), we measured NfL in CSF from 52 patients with lupus and 54 with pSS and explored associations with clinical, structural, immunological and biochemical abnormalities.

Methods

In CSF, we measured NfL, anti-P antibodies, protein S100B and TWEAK by ELISA and anti-NR2 antibodies by electrochemiluminescence. Anti-phospholipid antibodies and routine immunological tests were performed in blood. IgG and albumin were measured in CSF and serum for assessment of the blood–brain barrier function (Q-albumin) and intrathecal IgG production (IgG index). Cerebral MRI and neuropsychological testing were performed.

Results

A multivariable regression model showed that increasing CSF anti-NR2 antibody levels were associated with increasing NfL levels in patients with SLE (B 1.27, 95% CI 0.88–1.65, p < 0.001). Age contributed significantly in the model (B 0.04, 95% CI 0.03–0.05, p < 0.001). Similar findings were observed in the pSS group. Adjusted for age and sex, no associations were found between NfL levels and any MRI data. In SLE patients, higher NfL concentrations were associated with impairments in psychomotor speed and motor function, and in pSS with motor dysfunction. These associations remained in multivariable regression models.

Conclusions

Increased concentration of NfL in CSF is a marker of cerebral involvement in patients with SLE and pSS, is strongly associated with the presence of anti-NR2 antibodies, and correlates with cognitive impairment in several domains.

Electronic supplementary material

Supplementary information is available for this paper at 10.1007/s00415-020-10290-y.

Molecular pathways in patients with systemic lupus erythematosus revealed by gene-centred DNA sequencing

Objectives

Systemic lupus erythematosus (SLE) is an autoimmune disease with extensive heterogeneity in disease presentation between patients, which is likely due to an underlying molecular diversity. Here, we aimed at elucidating the genetic aetiology of SLE from the immunity pathway level to the single variant level, and stratify patients with SLE into distinguishable molecular subgroups, which could inform treatment choices in SLE.

Methods

We undertook a pathway-centred approach, using sequencing of immunological pathway genes. Altogether 1832 candidate genes were analysed in 958 Swedish patients with SLE and 1026 healthy individuals. Aggregate and single variant association testing was performed, and we generated pathway polygenic risk scores (PRS).

Results

We identified two main independent pathways involved in SLE susceptibility: T lymphocyte differentiation and innate immunity, characterised by HLA and interferon, respectively. Pathway PRS defined pathways in individual patients, who on average were positive for seven pathways. We found that SLE organ damage was more pronounced in patients positive for the T or B cell receptor signalling pathways. Further, pathway PRS-based clustering allowed stratification of patients into four groups with different risk score profiles. Studying sets of genes with priors for involvement in SLE, we observed an aggregate common variant contribution to SLE at genes previously reported for monogenic SLE as well as at interferonopathy genes.

Conclusions

Our results show that pathway risk scores have the potential to stratify patients with SLE beyond clinical manifestations into molecular subsets, which may have implications for clinical follow-up and therapy selection.

OP0139 FUNCTIONAL EVALUATION OF THE SJÖGREN’S SYNDROME AND SYSTEMIC LUPUS ERYTHEMATOSUS DDX6-CXCR5 RISK INTERVAL

Background:

Sjögren’s Syndrome (SS) and Systemic Lupus Erythematosus (SLE) are distinct chronic, complex autoimmune diseases with shared characteristics such as autoantibodies, heightened interferons, and polyarthritis. SS and SLE genome-wide association studies (GWAS) report strong associations with theDDX6-CXCR5risk interval. DDX6 suppresses interferon stimulated gene expression and CXCR5 regulates T cell functions implicated in autoimmunity.

Objectives:

To identify functional variants that impact regulation in theDDX6-CXCR5interval.

Methods:

Fine-mapping was done using ImmunoChip data from 3785 SLE, 1916 SS cases and 6893 population controls of European ancestry that were imputed and tested for SNP-trait association. Bayesian statistics assigned posterior probabilities to SNPs and defined a credible set of risk variants. Bioinformatic analyses further prioritized variants with predicted functionality. Electrophoretic mobility shift assays (EMSAs) and luciferase expression were used to validate predicted SNPs in EBV transformed B (EBV B) cells.

Results:

While some differences were observed, the overall SS and SLE association signals were similar. SNP-SS rs9736016 nearCXCR5and SNP-SLE rs76409436 nearDDX6were the most significant but did not show evidence of functionality. Bayesian statistics defined credible sets of variants in strong D’ in common between both SS and SLE. Bioinformatics analyses (Haploreg, RegulomeDB, ENCODE data, etc) further refined the credible set and identified 5 common SNPs with strong evidence of functionality in immune cell types: rs4938572, rs4936443, rs57494551, rs7117261 and rs4938573. EMSAs showed a significant increase in protein binding to the risk allele of rs57494551 (p=0.0001), rs7117261 (p=0.0001) and rs4938573 (p=0.0003), but not the others, using nuclear lysates from EBV B cells. Luciferase vectors with a minimal promoter or no promoter were used to test for enhancer or promoter activity, respectively. To this end, the rs57494551 risk allele exhibited a significant increase in enhancer activity (p=0.0001). In contrast, the rs7117261 risk allele decreased enhancer activity (p=0.018). The rs4938573 risk allele decreased enhancer (p=0.043) and promoter (p=0.024) activity. While rs7117261 or rs4938573 were not reported in eQTL databases, GTex data reported rs57494551 as an eQTL that altersDDX6expression in whole blood (p=1.8E-7). Additionally, these functional SNPs have been associated with looping events to several proximal promoters in nearby genes in immune cells.

Conclusion:

SS and SLE have similar genomic architecture across theDDX6-CXCR5risk interval. Multiple variants in the credible set exhibited allele specific changes in protein binding, as well as modified enhancer activity, promoter activity or both. Ongoing studies will use Cas9 in EBV B cells to determine which other loci are within the local regulatory network.

Disclosure of Interests:

Mandi M Wiley: None declared, Bhuwan Khatri: None declared, Kandice L Tessneer: None declared, Michelle L Joachims: None declared, Anna M Stolarczyk: None declared, Astrid Rasmussen Speakers bureau: Novartis, ThermoFischer, Simon J. Bowman Consultant of: Astrazeneca, Biogen, BMS, Celgene, Medimmune, MTPharma, Novartis, Ono, UCB, xtlbio, Glapagos, Speakers bureau: Novartis, Lida Radfar: None declared, Roald Omdal: None declared, Marie Wahren-Herlenius: None declared, Blake M Warner: None declared, Torsten Witte: None declared, Roland Jonsson: None declared, Maureen Rischmueller: None declared, Patrick M Gaffney: None declared, Judith A. James Grant/research support from: Progentec Diagnostics, Inc, Consultant of: Abbvie, Novartis, Jannsen, Lars Ronnblom Grant/research support from: AZ, Speakers bureau: AZ, R Hal Scofield Grant/research support from: Pfizer, Xavier Mariette: None declared, Wan-fai Ng: None declared, Kathy L Sivils: None declared, Gunnel Nordmark: None declared, Betty Tsao: None declared, Christopher Lessard: None declared

OP0047 GENOME-WIDE ASSOCIATION STUDY OF SJÖGREN’S SYNDROME IDENTIFIES TEN NEW RISK LOCI

Background:

Sjögren’s syndrome (SS) is a complex autoimmune disease with exocrine gland dysfunction leading to substantial morbidity. There are 10 published genetic susceptibility loci.

Objectives:

Our genome-wide association study (GWAS) aimed to identify additional risk loci of genome-wide significance (GWS; p<5E-08) in European-derived primary SS.

Methods:

A total of 3232 cases and 17481 controls genotyped on GWAS arrays and 619 cases and 6171 controls genotyped on ImmunoChip (IC) arrays were imputed after quality control. Logistic regression was calculated adjusting for ancestry using the first 4 principal components to identify SS-associated SNPs. GWAS and IC results were meta-analyzed using weighted Z-scores. Bayesian statistics were used to assign posterior probabilities and define credible SNP sets for each locus. Bioinformatic analyses were used to predict functionality.

Results:

Seven novel loci exceeded GWS in the GWAS analysis:NAB1,MIR146A-PTTG1,XKR6,MAPT-CRHR1,RPTOR-CHMP6-BAIAP2,TYK2andSYNGR1. Meta-analysis with IC data identified three more novel loci exceeding GWS:CD247,PRDM1-ATG5andTNFAIP3. Several additional loci with suggestive association (p<1E-05) were also identified:ADAMTSL2,CGNL1andPHRF1.

Several identified loci have reported functional implications in immune regulation and autoimmune disease. In lupus, rs2431697 correlated with rs2431098, which was shown to alterMIR146Aexpression, resulting in type I interferon pathway imbalance. Similarly,TYK2risk association reportedly drives interferon, IL10 and RET signaling pathways.PRDM1encodes Blimp-1, a master regulator of immune cell differentiation.CD247encodes the zeta subunit of the T cell receptor complex.XKR6is implicated in apoptotic cell ingestion.ATG5is also involved in apoptosis, as well as autophagy and antigen presentation.

Additional bioinformatics analyses (Haploreg, Regulome DB, ENCODE, etc.) revealed immune-relevant functional implications for each risk locus. The SS-associated credible set included variants downstream ofTNFAIP3in a region reported to abolish looping between an enhancer and theTNFAIP3promoter in lupus and a coding variant that has been shown to alter NF-kB activity and neutrophil extra-cellular traps. The rs2293765 in the 5’ UTR ofNAB1showed evidence of enhancer/promoter activities. The rs2069235 in theSYNGR1locus showed enhancer and transcription start site activities in B and T cells. The rs7210219 in theMAPT-CRHR1locus showed enhancer/promotor activities in various tissues.

Conclusion:

We have identified ten novel genetic susceptibility loci associated with SS pathology. Our finding increases the current number of GWS regions in SS patients of European origin, from 10 to 20. Future work is needed to identify and characterize the functional variants in each region.

Disclosure of Interests:

Bhuwan Khatri: None declared, Tove Ragna Reksten: None declared, Kandice L Tessneer: None declared, Astrid Rasmussen Speakers bureau: Novartis, ThermoFischer, R Hal Scofield Grant/research support from: Pfizer, Simon J. Bowman Consultant of: Astrazeneca, Biogen, BMS, Celgene, Medimmune, MTPharma, Novartis, Ono, UCB, xtlbio, Glapagos, Speakers bureau: Novartis, Joel Guthridge Grant/research support from: Xencor, Bristol Myers Squibb, DXterity, Judith A. James Grant/research support from: Progentec Diagnostics, Inc, Consultant of: Abbvie, Novartis, Jannsen, Lars Ronnblom Grant/research support from: AZ, Speakers bureau: AZ, Blake M Warner: None declared, Xavier Mariette: None declared, Roald Omdal: None declared, Javier Martin Ibanez: None declared, Maria Teruel: None declared, Janicke Liaaen Jensen: None declared, Lara A Aqrawi: None declared, Øyvind Palm: None declared, Marie Wahren-Herlenius: None declared, Torsten Witte: None declared, Roland Jonsson: None declared, Maureen Rischmueller: None declared, A Darise Farris Speakers bureau: Biogen, Marta Alarcon-Riquelme: None declared, Wan-fai Ng: None declared, Kathy L Sivils: None declared, Gunnel Nordmark: None declared, Christopher Lessard: None declared

Primary Sjögren's syndrome and the eye

Primary Sjögren syndrome is an autoimmune disease that mainly affects exocrine glands such as the salivary and lacrimal glands. In addition, systemic involvement is common. Primary Sjögren syndrome is of particular interest to ophthalmologists as it constitutes an important differential diagnosis in conditions with dry eye disease. In addition, ocular tests for more precisely diagnosing and monitoring primary Sjögren syndrome have become increasingly important, and new therapeutics for local and systemic treatment evolve as a result of increased understanding of immunological mechanisms and molecular pathways in the pathogenesis of primary Sjögren syndrome. We provide an update of interest to ophthalmologists regarding pathogenesis, diagnosis, investigative procedures, and treatment options.

Heat-shock protein 90 in plasma reflects severity of fatigue in patients with Crohn's disease

Heat-shock proteins (HSPs) are evolutionarily conserved proteins with important cellular homeostasis functions during harmful conditions, including inflammation. Some HSPs are secreted extracellularly and act on distant cells by down-regulating inflammation and increasing cellular stress defence mechanisms. HSP90α has been postulated to signal fatigue in chronic inflammation. We investigated whether HSP90α is associated with fatigue in patients with Crohn’s disease. Fifty-three patients with newly diagnosed Crohn’s disease were included in a cross-sectional study. Data on demographics and disease distribution were obtained. Fatigue was measured by the fatigue visual analogue scale (fVAS). Disease activity was assessed by the Simple Endoscopic Score for Crohn’s disease and Harvey Bradshaw Index. C-reactive protein, faecal calprotectin and HSP90α were also measured. The median fVAS score was 52 mm, indicating significant fatigue. HSP90α scores correlated significantly with fVAS (r = 0.31, P = 0.03). In a multivariate regression model, HSP90α was the only significant contributor to fVAS scores (β = 0.31, P = 0.03). When patients were dichotomised into groups with high and low HSP90α concentrations, significantly higher fVAS scores were demonstrated in the group with high HSP90α (M = 62.4, confidence interval 53.0–71.8 vs. 43.3, 31.6–55.0; P = 0.01). Thus, HSP90α may contribute to fatigue generation and/or modulation in patients with Crohn’s disease.

Determination of lower cut-off levels of adalimumab associated with biochemical remission in Crohn's disease

Background and Aim

Adalimumab is administered and dosed using a standardized treatment regimen. Although therapeutic drug monitoring (TDM) may help optimize treatment efficacy, the lower cut‐off concentration of adalimumab needed to retain disease remission has not been established. This cross‐sectional study of patients with Crohn's disease on stable medication aimed to determine a lower therapeutic drug concentration threshold of adalimumab associated with biochemical disease remission.

Methods

C‐reactive protein (CRP) and fecal calprotectin were used as established markers and albumin as an explorative marker of disease activity. Time since introduction, treatment interval, drug dosage, serum drug concentration and antidrug antibodies, disease duration, age, and sex were recorded.

Results

The study included 101 patients who were divided into “active disease” and “remission” groups for inflammatory markers based on cut‐off levels of 5 mg/L for CRP and 50 mg/kg for fecal calprotectin. Cut‐off levels for albumin of 36.5 and 41.5 g/L were also added as further indicatives of remission. Receiver operating characteristic analysis found optimal thresholds for adalimumab associated with remission at 6.8–7.0 mg/L for the combination of CRP and fecal calprotectin and when combining CRP, fecal calprotectin, and albumin.

Conclusions

In patients with Crohn's disease, serum adalimumab of at least 6.8 mg/L was associated with biochemical disease remission based on CRP and fecal calprotectin, supporting the use of TDM to ensure disease control. Albumin should be further tested in this setting.

Symptom-based stratification of patients with primary Sjögren's syndrome: multi-dimensional characterisation of international observational cohorts and reanalyses of randomised clinical trials

BACKGROUND

Heterogeneity is a major obstacle to developing effective treatments for patients with primary Sjögren's syndrome. We aimed to develop a robust method for stratification, exploiting heterogeneity in patient-reported symptoms, and to relate these differences to pathobiology and therapeutic response.

METHODS

We did hierarchical cluster analysis using five common symptoms associated with primary Sjögren's syndrome (pain, fatigue, dryness, anxiety, and depression), followed by multinomial logistic regression to identify subgroups in the UK Primary Sjögren's Syndrome Registry (UKPSSR). We assessed clinical and biological differences between these subgroups, including transcriptional differences in peripheral blood. Patients from two independent validation cohorts in Norway and France were used to confirm patient stratification. Data from two phase 3 clinical trials were similarly stratified to assess the differences between subgroups in treatment response to hydroxychloroquine and rituximab.

FINDINGS

In the UKPSSR cohort (n=608), we identified four subgroups: Low symptom burden (LSB), high symptom burden (HSB), dryness dominant with fatigue (DDF), and pain dominant with fatigue (PDF). Significant differences in peripheral blood lymphocyte counts, anti-SSA and anti-SSB antibody positivity, as well as serum IgG, κ-free light chain, β2-microglobulin, and CXCL13 concentrations were observed between these subgroups, along with differentially expressed transcriptomic modules in peripheral blood. Similar findings were observed in the independent validation cohorts (n=396). Reanalysis of trial data stratifying patients into these subgroups suggested a treatment effect with hydroxychloroquine in the HSB subgroup and with rituximab in the DDF subgroup compared with placebo.

INTERPRETATION

Stratification on the basis of patient-reported symptoms of patients with primary Sjögren's syndrome revealed distinct pathobiological endotypes with distinct responses to immunomodulatory treatments. Our data have important implications for clinical management, trial design, and therapeutic development. Similar stratification approaches might be useful for patients with other chronic immune-mediated diseases.

FUNDING

UK Medical Research Council, British Sjogren's Syndrome Association, French Ministry of Health, Arthritis Research UK, Foundation for Research in Rheumatology. VIDEO ABSTRACT.

Effect of Biological Treatment on Fatigue in Psoriasis: A Systematic Review and Meta-Analysis

BACKGROUND

Fatigue is frequent in patients with psoriasis. Though conventional drugs in general have no effect on fatigue, biological agents have demonstrated beneficial effects in several other chronic inflammatory diseases.

OBJECTIVE

The objective of the present study was to evaluate the effect of biological drugs on fatigue in patients with psoriasis vulgaris.

METHODS

We conducted a meta-analysis of randomized controlled trials in which anti-interleukin-12/23, anti-interleukin-23, anti-interleukin-17, or anti-tumor necrosis factor-α agents were used for psoriasis vulgaris and fatigue was an outcome measure.

RESULTS

A total of eight randomized controlled trials fulfilled criteria for inclusion in the meta-analysis. The studies used two fatigue reporting scales: the Functional Assessment of Chronic Illness Therapy-Fatigue and the Short Form 36 Health Survey Vitality Subscale. Treatment by biological agents in general compared with placebo led to a significant reduction in fatigue, with a standardized mean difference of - 0.40 (95% confidence interval - 0.46 to - 0.34; p < 0.001).

CONCLUSION

Biological drugs used for the treatment of psoriasis vulgaris have a consistently small-to-moderate beneficial effect on fatigue independent of the type of drug.

Fatigue in celiac disease: A review of the literature

Fatigue is increasingly recognized as a significant problem in patients with chronic inflammatory and autoimmune diseases. In celiac disease, a chronic immune-mediated disease triggered by dietary gluten, conflicting opinions exist regarding both the size of the problem and the effect of a gluten-free diet (GFD) on fatigue. We reviewed the existing literature regarding fatigue in celiac disease. We conducted a systematic search in the Embase, Ovid Medline, and Cochrane databases using subject terms from controlled vocabularies. Articles were reviewed based on language, type of article, title, and abstract or full text. Eighteen articles were finally selected for review. Fatigue was significantly greater in patients with celiac disease compared to healthy control subjects. Fatigue prevalence ranged from 8 to 100%. Fatigue severity was assessed in six studies. The fatigue visual analogue scale was the most frequently used fatigue instrument with scores from 57 to 79 prior to starting a GFD and from 39 to 59 in patients on a GFD. Seven studies investigated the effect of a GFD on fatigue, including five studies that reported less fatigue while on the diet and two studies that showed no significant difference. This review concludes that fatigue is a substantial complaint in patients with celiac disease. A GFD seems to reduce fatigue, but existing data are limited.

Interleukin-1-related activity and hypocretin-1 in cerebrospinal fluid contribute to fatigue in primary Sjögren's syndrome

BACKGROUND

Fatigue is a common and sometimes debilitating phenomenon in primary Sjögren's syndrome (pSS) and other chronic inflammatory diseases. We aimed to investigate how IL-1 β-related molecules and the neuropeptide hypocretin-1 (Hcrt1), a regulator of wakefulness, influence fatigue.

METHODS

Hcrt1 was measured by radioimmunoassay (RIA) in cerebrospinal fluid (CSF) from 49 patients with pSS. Interleukin-1 receptor antagonist (IL-1Ra), IL-1 receptor type 2 (IL-1RII), IL-6, and S100B protein were measured by enzyme-linked immunosorbent assay (ELISA). Fatigue was rated by the fatigue visual analog scale (fVAS).

RESULTS

Simple univariate regression and multiple regression analyses with fatigue as a dependent variable revealed that depression, pain, and the biochemical variable IL-1Ra had a significant association with fatigue. In PCA, two significant components were revealed. The first component (PC1) was dominated by variables related to IL-1β activity (IL-1Ra, IL-1RII, and S100B). PC2 showed a negative association between IL-6 and Hcrt1. fVAS was then introduced as an additional variable. This new model demonstrated that fatigue had a higher association with the IL-1β-related PC1 than to PC2. Additionally, a third component (PC3) became significant between low Hcrt1 concentrations and fVAS scores.

CONCLUSIONS

The main findings of this study indicate a functional network in which several IL-1β-related molecules in CSF influence fatigue in addition to the classical clinical factors of depression and pain. The neuropeptide Hcrt1 seems to participate in fatigue generation, but likely not through the IL-1 pathway.

Fatigue in primary Sjögren's syndrome: A proteomic pilot study of cerebrospinal fluid

Objectives:

Fatigue is a frequent and often disabling phenomenon that occurs in patients with chronic inflammatory and immunological diseases, and the underlying biological mechanisms are largely unknown. Because fatigue is generated in the brain, we aimed to investigate cerebrospinal fluid and search for molecules that participate in the pathophysiology of fatigue processes.

Methods:

A label-free shotgun proteomics approach was applied to analyze the cerebrospinal fluid proteome of 20 patients with primary Sjögren’s syndrome. Fatigue was measured with the fatigue visual analog scale.

Results:

A total of 828 proteins were identified and the 15 top discriminatory proteins between patients with high and low fatigue were selected. Among these were apolipoprotein A4, hemopexin, pigment epithelium-derived factor, secretogranin-1, secretogranin-3, selenium-binding protein 1, and complement factor B.

Conclusion:

Most of the discriminatory proteins have important roles in regulation of innate immunity, cellular stress defense, and/or functions in the central nervous system. These proteins and their interacting protein networks may therefore have central roles in the generation and regulation of fatigue, and the findings contribute with evidence to the concept of fatigue as a biological phenomenon signaled through specific molecular pathways.

Tubulointerstitial nephritis and uveitis syndrome

BACKGROUND

Uveitis and acute renal failure can be seen in various immune-mediated systemic diseases. Here we present a case of a young man with a rare inflammatory oculorenal syndrome.

CASE REPORT

A man in his thirties was admitted with a constellation of fatigue, flank pain, weight loss and bilateral acute anterior uveitis. Laboratory tests showed anaemia, leukocytosis with eosinophilia, as well as elevated creatinine and C-reactive protein, and urine analyses demonstrated mild proteinuria. Work-up excluded sarcoidosis, Sjögren's syndrome, systemic lupus erythematosus, ANCA-associated vasculitides, Behçet disease, spondyloarthritis and infection. Renal biopsy showed severe tubulointerstitial nephritis.

INTERPRETATION

Following exclusion of the abovementioned disorders, a diagnosis of tubulointerstitial nephritis and uveitis (TINU) syndrome was made. TINU syndrome is a rare inflammatory disorder which can be diagnosed in patients presenting with uveitis and tubulointerstitial nephritis after exclusion of other causes of similar oculorenal involvement.

Thyroidectomy Versus Medical Management for Euthyroid Patients With Hashimoto Disease and Persisting Symptoms: A Randomized Trial

BACKGROUND

Hashimoto disease is a chronic autoimmune thyroiditis. Despite adequate hormone substitution, some patients have persistent symptoms that may be the result of immunologic pathophysiology.

OBJECTIVE

To determine whether thyroidectomy improves symptoms in patients with Hashimoto thyroiditis who still have symptoms despite having normal thyroid gland function while receiving medical therapy.

DESIGN

Randomized trial. (ClinicalTrials.gov: NCT02319538).

SETTING

Secondary care hospital in Norway.

PATIENTS

150 patients aged 18 to 79 years with persistent Hashimoto-related symptoms despite euthyroid status while receiving hormone replacement therapy and with serum antithyroid peroxidase (anti-TPO) antibody titers greater than 1000 IU/mL.

INTERVENTION

Total thyroidectomy or medical management with hormone substitution to secure euthyroid status in both groups.

MEASUREMENTS

The primary outcome was general health score on the Short Form-36 Health Survey (SF-36) at 18 months. Secondary outcomes were adverse effects of surgery, the other 7 SF-36 subscores, fatigue questionnaire scores, and serum anti-TPO antibody titers at 6, 12, and 18 months.

RESULTS

During follow-up, only the surgical group demonstrated improvement: Mean general health score increased from 38 to 64 points, for a between-group difference of 29 points (95% CI, 22 to 35 points) at 18 months. Fatigue score decreased from 23 to 14 points, for a between-group difference of 9.3 points (CI, 7.4 to 11.2 points). Chronic fatigue frequency decreased from 82% to 35%, for a between-group difference of 39 percentage points (CI, 23 to 53 percentage points). Median serum anti-TPO antibody titers decreased from 2232 to 152 IU/mL, for a between-group difference of 1148 IU/mL (CI, 1080 to 1304 IU/mL). In multivariable regression analyses, the adjusted treatment effects remained similar to the unadjusted effects.

LIMITATION

Results are applicable only to a subgroup of patients with Hashimoto disease, and follow-up was limited to 18 months.

CONCLUSION

Total thyroidectomy improved health-related quality of life and fatigue, whereas medical therapy did not. This improvement, along with concomitant elimination of serum anti-TPO antibodies, may elucidate disease mechanisms.

PRIMARY FUNDING SOURCE

Telemark Hospital.

Tolerability and safety of long-term rituximab treatment in systemic inflammatory and autoimmune diseases

Rituximab, an anti-CD20 monoclonal antibody causing selective B-cell depletion, is used for various systemic inflammatory and autoimmune diseases (SIADs). Long-term safety data on rituximab are limited. The objectives of this study were to evaluate the long-term safety and tolerability of rituximab treatment for SIADs. A retrospective, single-center observational study including all patients ≥ 16 years treated with rituximab for SIADs was performed. The electronic medical records were reviewed, and data concerning indication and duration of rituximab treatment, prior and concurrent immunosuppressive therapy, and adverse events such as infections requiring hospitalization, dysgammaglobulinemia and end organ damage, were collected. A total of 70 patients were included, with a median treatment duration of 54 months, ranging 30-138 months. The most common indications for rituximab treatment were granulomatosis with polyangiitis (22.9%), primary Sjögren's syndrome (20.0%) and systemic lupus erythematosus (14.3%). Infections and persistent dysgammaglobulinemia were the most common adverse events, occurring in 34.3% and 25.7%, respectively. A total of 64 infections were observed in 24 (34.3%) patients, including 1 case of fatal infection. Seventeen patients performed B-cell quantitation during the first 2 years following discontinuation, of which only four (19.0%) demonstrated B-cell reconstitution. End organ damage occurred in two patients, presenting as pyoderma gangrenosum and interstitial pneumonitis. No opportunistic infections were observed. Three patients died during the observational period, of which one was due to lethal infection. This study presents observational data with long treatment duration. It demonstrates that long-term rituximab treatment is relatively well tolerated, and that no cumulative side effects were observed.

Malondialdehyde and advanced oxidation protein products are not increased in psoriasis: a controlled study

This study investigated oxidative stress in patients with psoriasis of low and medium disease activity. We measured advanced oxidation protein products (AOPP) and malondialdehyde (MDA) in plasma using UV-spectrophotometry and high performance liquid chromatography connected to a fluorescence detector in 84 patients and 84 matched healthy subjects. AOPP is a marker of protein oxidation due to inflammation, whereas MDA is a hydroxyl radical initiated lipid peroxidation product. Clinico-demographic variables including age, gender, disease severity, and fatigue were assessed in relation to AOPP and MDA. Disease severity was evaluated with the Psoriasis Area and Severity Index and the Dermatology Life Quality Index. Median (interquartile range, IQR) AOPP concentrations were 66 µmol/l (IQR 54-102) in patients and 69 µmol/l (IQR 55-87) in healthy subjects (P = 0.75). Median plasma MDA concentrations were significantly lower in patients than in healthy subjects (0.68 µM, IQR 0.54-0.85 vs. 0.76 µM, IQR 0.60-0.97; P = 0.03). Plasma levels of AOPP and MDA did not indicate oxidative stress in patients with mild psoriasis. Higher AOPP concentrations were associated with male gender, high body mass index, and high hemoglobin values. Elevated MDA concentrations were associated with advanced age and male gender. No associations with disease severity were detected. Although, the two selected biomarkers do not provide a complete measure of oxidative damage, our study demonstrates that a number of physiological and methodological factors influence the levels of MDA and AOPP. Such methodological issues are important to consider when interpreting results using these biomarkers in patients with psoriasis.

Severe headache in primary Sjögren's syndrome treated with intrathecal rituximab

A severe and persistent migrainous headache in a patient with primary Sjøgren's syndrome unresponsive to treatment with immunosuppressive drugs, triptans, opioids, and NSAIDs, responded successfully to intrathecal B-cell depletion with rituximab. We hypothesize that brain-resident autoreactive B cells were involved in headache pathogenesis and were eliminated by this procedure.

Pain and fatigue in primary Sjögren's syndrome

Chronic fatigue, pain and depression are common in patients with primary Sjögren's syndrome. These phenomena mutually affect each other and have a considerable impact on the patients' quality of life. While pain is usually regarded as a fairly somatic phenomenon, both fatigue and depression have traditionally been regarded as more-or-less of psychological origin. There is an increasing understanding that this picture is multifaceted; that there is a genetic foundation, and that biological mechanisms regulate the clinical expression through activation of evolutionary, deeply conserved neuronal pathways in the brain. This pattern is evident not only in primary Sjögren's syndrome, but also in other systemic inflammatory autoimmune diseases, in cancer and in neurodegenerative diseases like Parkinson's disease. This article will mainly focus on the biology of pain and fatigue. We describe how these factors influence each other, and act with the overarching purpose of defending the organism against harm and danger.

Fatigue is common and severe in patients with mastocytosis

Chronic fatigue is a common phenomenon in inflammatory and autoimmune conditions, in cancer, and in neurodegenerative diseases. Although pain and psychological factors influence fatigue, there is an increasing understanding that there is a genetic basis, and that activation of the innate immune system is an essential generator of fatigue. Mast cells are important actors in innate immunity and serve specialized defense responses against parasites and other pathogens. They are also major effector cells in allergic reactions. Primary disorders causing constitutively hyperactivity of mast cells are called mastocytosis and are frequently due to a gain-of-function mutation of the KIT gene encoding the transmembrane tyrosine kinase receptor. It is a clinical experience that patients with mast cell disorders suffer from fatigue, but there is a lack of scientific literature on the phenomenon. We performed a controlled study of fatigue in mastocytosis patients and document a 54% prevalence of clinical significant fatigue.

Heat shock protein 90 and inflammatory activity in newly onset Crohn's disease

OBJECTIVE

The aim of the study was to investigate whether heat shock protein (HSP)90α plasma concentrations were associated with disease activity in patients with Crohn's disease.

MATERIALS AND METHODS

This cross-sectional study included 53 patients who were newly diagnosed with Crohn's disease. Demographic data and disease distribution were recorded, and disease activity was rated using the Simple Endoscopic Score for Crohn's Disease (SES-CD) and the Harvey Bradshaw Index (HBI). Faecal calprotectin and plasma concentrations of CRP and HSP90α were measured.

RESULTS

The median SES-CD was 7, and the median HSP90α level was 17.2 ng/mL. The HSP90α level was significantly correlated with SES-CD, CRP, and faecal calprotectin, but not with HBI. Linear regression analysis revealed that HSP90α was significantly associated with SES-CD (r² = 0.27, p < .001) and with CRP (r² = 0.18, p = .002). HSP90α concentrations were significantly higher in the 10 patients with the highest SES-CD scores compared to the 10 patients with the lowest SES-CD scores.

CONCLUSIONS

Objective measures of disease activity and inflammation in Crohn's disease - SES-CD and CRP - were closely associated with HSP90α concentrations in plasma, suggesting that HSP90α may be a biomarker of Crohn's disease.

The blood-brain barrier, TWEAK, and neuropsychiatric involvement in human systemic lupus erythematosus and primary Sjögren's syndrome

OBJECTIVE

A prevailing hypothesis for neuropsychiatric involvement in systemic lupus erythematosus (SLE) and primary Sjögren's syndrome is that brain reactive autoantibodies enter the brain through a disrupted blood-brain barrier. Our aim was to investigate whether TNF-like weak inducer of apoptosis (TWEAK) plays a role in cerebral involvement in human SLE and primary Sjögren's syndrome, and whether an impaired blood-brain barrier is a prerequisite for neuropsychiatric manifestations.

METHODS

TWEAK was measured in the cerebrospinal fluid and serum and compared with markers of blood-brain barrier permeability (Q-albumin and MRI contrast-enhanced lesions) and S100B, an astrocyte activation marker in 50 SLE and 52 primary Sjögren's syndrome patients. Furthermore, we estimated the general intrathecal B-cell activation (IgG index), measured anti-NR2 antibodies in cerebrospinal fluid, and explored whether these variables were associated with neuropsychiatric manifestations.

RESULTS

No associations were found between TWEAK in the cerebrospinal fluid or serum and neuropsychiatric manifestations in SLE nor in primary Sjögren's syndrome patients. Furthermore, no associations were found between neuropsychiatric manifestations and indicators of blood-brain barrier integrity or astroglial activity. Anti-NR2 antibodies were associated with impaired visuospatial processing (odds ratio 4.9, P = 0.03) and motor functioning (odds ratio 6.0, P = 0.006).

CONCLUSION

No clinical neuropsychiatric manifestations could be attributed to impaired integrity of the blood-brain barrier, or to TWEAK levels in cerebrospinal fluid or serum in either patient group. The TWEAK concentration was considerably higher in the cerebrospinal fluid than in blood, which indicates intrathecal production. We hypothesize that increased TWEAK and S100B result from immunological stress caused by brain-reactive antibodies produced by brain residing immune cells.