Doubtful Clinical Value of Subtyping Anti-U1-RNP Antibodies Regarding the RNP-70 kDa Antigen in Sera of Patients with Systemic Lupus Erythematosus

The detection of antinuclear antibodies is central to the diagnosis and prognosis of systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS) and mixed connective tissue disease (MCTD). Anti-U1-RNP and anti-RNP70 antibodies were assayed in the sera of patients with SLE (n = 114), pSS (n = 54) and MCTD (n = 12). In the SLE group, 34/114 (30%) were anti-U1-RNP positive, and 21/114 (18%) were both anti-RNP70 positive and anti-U1-RNP positive. In the MCTD group, 10/12 (83%) were anti-U1-RNP positive, and 9/12 (75%) were anti-RNP70 positive. Only one individual with pSS was antibody positive (for both anti-U1-RNP and anti-RNP70). All anti-RNP70-positive samples were also anti-U1-RNP positive. Anti-U1-RNP-positive subjects with SLE were younger (p < 0.0001); showed lower concentrations of complement protein 3 (p = 0.03); had lower eosinophil (p = 0.0005), lymphocyte (p = 0.006) and monocyte (p = 0.03) counts; and had accrued less organ damage (p = 0.006) than the anti-U1-RNP-negative SLE patients. However, we observed no significant clinical or laboratory parameter differences between the anti-U1-RNP-positive individuals with/without anti-RNP70 in the SLE group. In conclusion, anti-RNP70 antibodies are not exclusive to MCTD but are rarely detected in pSS and healthy individuals. In SLE, anti-U1-RNP antibodies are associated with a clinical phenotype that resembles MCTD, with hematologic involvement and less damage accrual. Based on our results, the clinical value of subtyping anti-RNP70 in anti-U1-RNP-positive sera appears to be of limited value.

Serum levels of soluble urokinase plasminogen activator receptor in juvenile idiopathic arthritis: a single-center Swedish case-control study

OBJECTIVES

Reliable biomarkers in the early stages of idiopathic arthritis (JIA) are scarce and the disease heterogeneity makes it clinically challenging to predict the risk of joint damage. Biomarkers with prognostic potential are warranted in order to individualize treatment and follow-up in JIA. The soluble urokinase plasminogen activator receptor (suPAR) has been reported as an easily measurable biomarker for prognosis and severity in several rheumatic diseases but it has never been studied in JIA.

METHODS

Sera from 51 well-characterized patients with JIA and 50 age- and sex-matched control subjects were collected and stored for later analysis of suPAR. Patients were carefully followed clinically over 3 years and analysis of erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (anti-CCP) were analyzed as part of clinical routine. Signs of joint erosions were evaluated by radiography.

RESULTS

Overall, the levels of suPAR did not differ significantly between JIA patients and controls but those with polyarticular involvement showed higher suPAR (p = 0.013). In addition, elevated suPAR were associated with joint erosions (p = 0.026). Two RF/anti-CCP negative individuals with erosions showed high levels of suPAR.

CONCLUSIONS

We present new data on the biomarker suPAR in JIA. Our results indicate that, apart from RF and anti-CCP, analysis of suPAR could be of additional value in assessing the risk of erosions. Analysis of suPAR early could potentially guide treatment decision-making in JIA, but our observations should be confirmed in prospective studies.

Prominent epigenetic and transcriptomic changes in CD4+ and CD8+ T cells during and after pregnancy in women with multiple sclerosis and controls

BACKGROUND

Multiple sclerosis (MS) is a neuroinflammatory disease in which pregnancy leads to a temporary amelioration in disease activity as indicated by the profound decrease in relapses rate during the 3rd trimester of pregnancy. CD4⁺ and CD8⁺ T cells are implicated in MS pathogenesis as being key regulators of inflammation and brain lesion formation. Although Tcells are prime candidates for the pregnancy-associated improvement of MS, the precise mechanisms are yet unclear, and in particular, a deep characterization of the epigenetic and transcriptomic events that occur in peripheral T cells during pregnancy in MS is lacking.

METHODS

Women with MS and healthy controls were longitudinally sampled before, during (1st, 2nd and 3rd trimesters) and after pregnancy. DNA methylation array and RNA sequencing were performed on paired CD4⁺ and CD8⁺ T cells samples. Differential analysis and network-based approaches were used to analyze the global dynamics of epigenetic and transcriptomic changes.

RESULTS

Both DNA methylation and RNA sequencing revealed a prominent regulation, mostly peaking in the 3rd trimester and reversing post-partum, thus mirroring the clinical course with improvement followed by a worsening in disease activity. This rebound pattern was found to represent a general adaptation of the maternal immune system, with only minor differences between MS and controls. By using a network-based approach, we highlighted several genes at the core of this pregnancy-induced regulation, which were found to be enriched for genes and pathways previously reported to be involved in MS. Moreover, these pathways were enriched for in vitro stimulated genes and pregnancy hormones targets.

CONCLUSION

This study represents, to our knowledge, the first in-depth investigation of the methylation and expression changes in peripheral CD4⁺ and CD8⁺ T cells during pregnancy in MS. Our findings indicate that pregnancy induces profound changes in peripheral T cells, in both MS and healthy controls, which are associated with the modulation of inflammation and MS activity.

Autoantibodies associated with systemic sclerosis in three autoimmune diseases imprinted by type I interferon gene dysregulation: a comparison across SLE, primary Sjögren's syndrome and systemic sclerosis

OBJECTIVE

SLE, primary Sjögren's syndrome (pSS) and systemic sclerosis (SSc) are heterogeneous autoimmune diseases with a dysregulated type I interferon (IFN) system. The diseases often show overlapping clinical manifestations, which may result in diagnostic challenges. We asked to which extent SSc-associated autoantibodies are present in SLE and pSS, and whether these link to serum IFN-α, clinical phenotypes and sex. Samples with clinical data from patients with SSc and healthy blood donors (HBDs) served as controls. Finally, the diagnostic performance of SSc-associated autoantibodies was evaluated.

METHODS

Samples from well-characterised subjects with SLE (n=510), pSS (n=116), SSc (n=57) and HBDs (n=236) were analysed using a commercially available immunoassay (EuroLine Systemic Sclerosis Profile (IgG)). IFN-α was quantified by ELISA. Self-reported data on Raynaud's phenomenon (RP) were available.

RESULTS

With exceptions for anti-Ro52/SSA and anti-Th/To, SSc-associated autoantibodies were more frequent in SSc than in SLE, pSS and HBDs regardless of sex. IFN-α levels correlated with the number of positive SSc-associated autoantibodies (r=0.29, p<0.0001) and associated with Ro52/SSA positivity (p<0.0001). By using data from SLE, SSc and HBDs, RP was significantly associated with topoisomerase I, centromere protein (CENP)-B, RNA polymerase III 11 kDa, RNA polymerase III 155 kDa and PM-Scl100 whereas Ro52/SSA associated inversely with RP. In SLE, CENP-A was associated with immunological disorder, CENP-B with serositis and Ku with lupus nephritis. By combining analysis of ANA (immunofluorescence) with SSc-associated autoantibodies, the diagnostic sensitivity reached 98% and the specificity 33%.

CONCLUSIONS

The 13 specificities included in the EuroLine immunoassay are commonly detected in SSc, but they are also frequent among individuals with other diseases imprinted by type I IFNs. These findings are valuable when interpreting serological data on patients with suspected SSc, especially as patients may present with disease manifestations overlapping different rheumatological diseases. In SLE, we observed associations between manifestations and SSc-associated autoantibodies which have not previously been reported.

OCT and VEP correlate to disability in secondary progressive multiple sclerosis

BACKGROUND

The afferent visual pathway provides a unique opportunity to monitor clinical and subclinical optic neuritis and features of neuroaxonal degeneration in secondary progressive MS.

OBJECTIVE

To investigate the usefulness of visual evoked potentials (VEP) and optical coherence tomography (OCT) in evaluating SPMS, and the association between these modalities and clinical course and lesion load on the magnetic resonance imaging (MRI) in patients with SPMS with or without a history of optic neuritis (ON).

METHODS

SPMS patients (n = 27) underwent clinical assessment with Expanded Disability Status Scale (EDSS) grading, visual acuity, OCT, and VEP examination. MRI of the brain and spinal cord were evaluated. Ordinal scores of VEP and MRI findings were used in the statistical analyses.

RESULTS

The ganglion cell and inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) thickness correlated with VEP latency. VEP P100 score correlated with EDSS. Linear regression showed an association between GCIPL thickness and EDSS as well as VEP P100 latency and EDSS. The MRI analyses were negative.

CONCLUSION

VEP latency and GCIPL thickness correlated with disability measured as EDSS in patients with SPMS and are useful in monitoring SPMS patients.

IgA rheumatoid factor in rheumatoid arthritis

OBJECTIVES

Rheumatoid factor (RF) is a well-established marker for the diagnosis and classification of rheumatoid arthritis (RA). Most studies evaluated IgM RF or isotype-nonspecific total RF assays. We evaluated the added value of IgA RF in this context.

METHODS

An international sample cohort consisting of samples from 398 RA patients and 1073 controls was tested for IgA RF with 3 commercial assays. For all RA patients and 100 controls essential clinical and serological data for ACR/EULAR classification were available.

RESULTS

The sensitivity of IgA RF for diagnosing RA was lower than the sensitivity of IgM RF. Differences in numerical values between IgA RF assays were observed. With all assays, the highest IgA RF values were found in patients with primary Sjögren's syndrome. Double positivity for IgM RF and IgA RF had a higher specificity for RA than either IgM RF or IgA RF. The sensitivity of double positivity was lower than the sensitivity of either IgA RF or IgM RF. Single positivity for IgA RF was at least as prevalent in controls than in RA patients. Adding IgA RF to IgM RF and anti-citrullinated protein antibodies (ACPA) did not affect RA classification. However, combined positivity for IgA RF, IgM RF and IgG ACPA had a higher specificity and lower sensitivity for RA classification than positivity for either of the antibodies.

CONCLUSIONS

IgA RF showed a lower sensitivity than IgM RF. Combining IgA RF with IgM RF and ACPA did not improve sensitivity of RA classification. Combined positivity (IgA-RF/IgM-RF/ACPA) increased specificity.

Autoantibodies Associated with Autoimmune Liver Diseases in a Healthy Population: Evaluation of a Commercial Immunoblot Test

Autoantibodies constitute important tools for diagnosing the autoimmune liver diseases (AILD) autoimmune hepatitis and primary biliary cholangitis. The EUROLINE immunoblot assay, detecting multiple specificities, is widely used, but the clinical importance of weakly positive findings is unclear. The manufacturer’s recommended cut-off was evaluated by investigating AILD-associated autoantibodies in 825 blood donors and 60 confirmed AILD cases. Positive findings were followed up with immunofluorescence microscopy on rat tissue, anti-M2-ELISA, alternative immunoblot assay, and liver function tests. Thirty-six (4.4%) blood donors were positive with EUROLINE. The most common specificities were LC-1 (1.6%), gp210 (1.3%), and AMA-M2 (1.1%). In general, the positive results were higher in patients than in blood donors, whereas anti-LC-1 was higher in blood donors. The liver function tests were slightly elevated in 2 of the 36 immunoblot positive blood donors. The majority of the positive EUROLINE findings could not be confirmed with the follow-up tests. The EUROLINE-Autoimmune Liver Diseases-(IgG) immunoblot detected autoantibodies in 4.4% of blood donors without signs of AILD. Our findings indicate that the recommended cut-off can be raised for most specificities without loss of diagnostic sensitivity. The prevalence of anti-LC-1 among blood donors indicates a problem with the antigen source.

Standardisation of ACPA tests: evaluation of a new candidate reference preparation

INTRODUCTION

Commercial assays measuring antibodies to citrullinated protein/peptide (ACPA) show poor quantitative agreement. The diagnostic industry has never adopted the International Union of Immunological Societies-Centers for Disease Control and Prevention (IUIS-CDC) ACPA reference standard. Recently, the National Institute for Biological Standards and Control (NIBSC) prepared a new candidate ACPA standard (18/204). We evaluated both reference materials using different commercially available ACPA assays.

MATERIALS AND METHODS

This is an international study in which the NIBSC candidate ACPA standard and the IUIS-CDC ACPA reference material were analysed together with 398 diagnostic samples from individuals with rheumatoid arthritis (RA) and in 1073 individuals who did not have RA using nine commercial ACPA assays.

RESULTS

For both reference materials and samples from individuals with RA and individuals who did not have RA, there were large differences in quantitative ACPA results between assays. For most assays, values for the IUIS-CDC standard were lower than values for NIBSC 18/204 and the IUIS-CDC/NIBSC ratio was comparable for several, but not all assays. When NIBSC 18/204 was used as a calibrator, an improvement in alignment of ACPA results across several of the evaluated assays was obtained. Moreover, NIBSC 18/204 could align clinical interpretation for some but not all assays.

CONCLUSION

Adoption of an international standard for ACPA determination is highly desirable. The candidate NIBSC 18/204 standard improved the standardisation and alignment of most ACPA assays and might therefore be recommended to be used as reference in commercial assays.

POS0536 REFINING THE SEROLOGICAL SCORES OF THE ACR/EULAR 2010 RHEUMATOID ARTHRITIS CLASSIFICATION CRITERIA: AN INTERNATIONAL STUDY

Background

Rheumatoid factor (RF) and anti-cyclic citrullinated protein/peptide antibodies (ACPA) are included in the ACR/EULAR 2010 classification criteria for rheumatoid arthritis (RA)(1). Both markers are given the same weight in the criteria.

Objectives

As the performance characteristics differ significantly between RF and ACPA(2), we set out to refine the serological scores for RA classification.

Methods

Diagnostic samples from 398 RA patients and from 1073 diseased controls were evaluated with five RF assays (two RF IgM isotype-specific assays and three total RF assays) and five ACPA IgG assays from five different manufacturers.

Results

Firstly, we harmonized thresholds between manufacturers based on predefined specificity for low positive (at 92.5% specificity for RF and at 97.5% specificity ACPA) and high positive results (at 97.5% specificity RF and at 99.0% specificity for ACPA). Next, we determined likelihood ratios (LRs) for RF, ACPA, and combinations of both, for negative, low positive, and high positive results. The LR was higher for ACPA than for RF, for high positive results than for low positive results and for double positivity than for single positivity. Based on these data we refined the weights of serological scores for classification (Table 1).

Table 1.

Refined weights of serological scores for RA classification

RF negativeRF low positiveRF high positiveACPA negative011ACPA low positive233ACPA high positive344

Application of such refined serological weights significantly increased the area under the curve of receiver operating characteristics analysis to distinguish RA from controls, significantly reduced the serological scores in the controls as well as the number of RA misclassifications without affecting the diagnostic sensitivity.

Besides, we showed that combining predefined specificity thresholds with the refined serological scoring, reduced manufacturer-dependent variability in RA classification impacting RA classification for controls from 18.0-29.0% by ACR/EULAR to 11.0-13.0% (significantly increasing specificity) and for RA patients from 67.8-74.0% to 67.6-71.5% (without significantly affecting sensitivity).

Conclusion

Serological weight factors for RA classification can be improved by taking into account the antibody type (RF versus ACPA), the antibody level, and single or combined positivity.

References

[1]Aletaha D, Neogi T, Silman AJ, Funovits J, Felson DT, Bingham COr, et al. 2010 rheumatoid arthritis classification criteria: an American College of Rheumatology/European League Against Rheumatism collaborative initiative. Ann Rheum Dis 2010; 69: 1580-8.

[2]Bossuyt X. Anticitrullinated protein antibodies: taking into account antibody levels improves interpretation. Ann Rheum Dis 2017; 76: e33.

Acknowledgements

We thank all participating diagnostic companies for the in-kind support of assays, their technical training and the constructive discussions. Furthermore, we are very thankful to the laboratory technicians of all participating laboratories for their most appreciated assistance in the performance of the RF/ACPA analyses.

Disclosure of Interests

Lieve Van Hoovels Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher, Grant/research support from: Thermo Fisher, Bert Vander Cruyssen: None declared, Daniela Sieghart Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher, Carolien Bonroy: None declared, Eszter Nagy: None declared, Rille Pullerits: None declared, Saša Čučnik: None declared, Charlotte Dahle: None declared, Ingmar Heijnen Speakers bureau: Thermo Fisher, Luca Bernasconi Speakers bureau: Thermo Fisher, Farid Benkhadra: None declared, Laura Bogaert: None declared, Stefanie Van Den Bremt: None declared, Ann Vanliedekerke: None declared, Geert Vanheule: None declared, Johan Robbrecht: None declared, Lucy Studholme: None declared, Wirth Claudine: None declared, Rüdiger Müller: None declared, Diego Kyburz: None declared, Christopher Sjowall: None declared, Alf Kastbom: None declared, Rok Jese: None declared, Boja Jovancevic: None declared, Emese Virag Kiss: None declared, Peggy Jacques: None declared, Günter Steiner Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher, Patrick Verschueren: None declared, Xavier Bossuyt Speakers bureau: Thermo Fisher, Consultant of: Thermo Fisher.

Multicentre study to improve clinical interpretation of rheumatoid factor and anti-citrullinated protein/peptide antibodies test results

BACKGROUND

Rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA) are important biomarkers for diagnosis of rheumatoid arthritis (RA). However, there is poor harmonisation of RF and ACPA assays. The aim of this study was to refine RF and ACPA interpretation across commercial assays.

MATERIALS AND METHODS

Six total RF isotype-non-specific assays, 3 RF IgM isotype-specific assays and 9 ACPA immunoglobulin G assays of 13 different companies were evaluated using 398 diagnostic samples from patients with RA and 1073 disease controls.

RESULTS

Using cut-offs proposed by the manufacturer, there was a large variability in diagnostic sensitivity and specificity between assays. Thresholds of antibody levels were determined based on predefined specificities and used to define test result intervals. Test result interval-specific likelihood ratios (LRs) were concordant across the different RF and ACPA assays. For all assays, the LR for RA increased with increasing antibody level. Higher LRs were found for ACPA than for RF. ACPA levels associated with LRs >80 were found in a substantial fraction (>22%) of patients with RA.

CONCLUSION

Defining thresholds for antibody levels and assigning test result interval-specific LRs allows alignment of clinical interpretation for all RF and ACPA assays.

Fatigue Is Common in Immunoglobulin G Subclass Deficiency and Correlates With Inflammatory Response and Need for Immunoglobulin Replacement Therapy

Purpose

Individuals with immunoglobulin G deficiency (IgGsd) often complain of fatigue. The correlation between systemic inflammation and fatigue is unknown. In this study perceived quality of life (QoL) and fatigue in individuals with IgGsd, on and off immunoglobulin replacement therapy (IgRT) were correlated to inflammatory markers in plasma to identify the subgroup that benefits from IgRT.

Method

Thirty-five IgGsd-patients were sampled on three occasions: at baseline, after being on IgRT for at least 18 months, and 18 months after discontinuation of IgRT. Short form 36, EQ-5D-5L visual analogue scale and fatigue impact scale questionnaires were used for evaluation of QoL and fatigue. Furthermore, a panel of 92 inflammatory markers were analysed in plasma. Thirty-two gender- and age-matched healthy individuals were included as controls and sampled on one occasion.

Results

QoL was lower and perceived fatigue higher in IgGsd compared to the controls. Severe fatigue and low QoL were associated with the need to restart IgRT (which is considered in IgGsd-individuals with a high burden of infections in Sweden). Twenty-five inflammatory factors were dysregulated in IgGsd and the plasma protein patterns were similar regardless of whether IgRT was ongoing or not. Enrichment analysis indicated IL-10 signalling as the most affected pathway. Severe fatigue was associated with decreased levels of the neurotrophic factors VEGFA and CSF-1.

Conclusion

Fatigue is a major contributory factor to impaired health-related QoL in IgGsd and is related to the need for IgRT. Low-grade systemic inflammation is a potential driver of fatigue. In addition to the burden of infections, we suggest the degree of fatigue should be considered when the decision to introduce IgRT is made.

Initial cognitive impairment predicts shorter survival of patients with glioblastoma

OBJECTIVES

Seizures as presenting symptom of glioblastoma (GBM) are known to predict prolonged survival, whereas the clinical impact of other initial symptoms is less known. Our main objective was to evaluate the influence of different presenting symptoms on survival in a clinical setting. We also assessed lead times, tumour size and localization.

METHODS

Medical records of 189 GBM patients were reviewed regarding the first medical appointment, presenting symptom/s, date of diagnostic radiology and survival. Tumour size, localization and treatment data were retrieved. Overall survival was calculated using Kaplan-Meier and Mann-Whitney U test. Cox regression was used for risk estimation.

RESULTS

Cognitive impairment as the initial symptom was often misinterpreted in primary health care leading to a delayed diagnosis. Initial global symptoms (66% of all patients) were associated with reduced survival compared to no global symptoms (median 8.4 months vs. 12.6 months). Those with the most common cognitive dysfunctions: change of behaviour, memory impairment and/or disorientation had a reduced median survival to 6.4 months. In contrast, seizures (32%) were associated with longer survival (median 11.2 months vs. 8.3 months). Global symptoms were associated with larger tumours than seizures, but tumour size had no linear association with survival. The setting of the first medical appointment was evenly distributed between primary health care and emergency units.

CONCLUSION

Patients with GBM presenting with cognitive symptoms are challenging to identify, have larger tumours and reduced survival. In contrast, epileptic seizures as the first symptom are associated with longer survival and smaller tumours.

SARS-CoV-2 Antibody Isotypes in Systemic Lupus Erythematosus Patients Prior to Vaccination: Associations With Disease Activity, Antinuclear Antibodies, and Immunomodulatory Drugs During the First Year of the Pandemic

Objectives

Impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic on individuals with arthritis has been highlighted whereas data on other rheumatic diseases, e.g., systemic lupus erythematosus (SLE), are scarce. Similarly to SLE, severe SARS-CoV-2 infection includes risks for thromboembolism, an unbalanced type I interferon response, and complement activation. Herein, SARS-CoV-2 antibodies in longitudinal samples collected prior to vaccination were analyzed and compared with SLE progression and antinuclear antibody (ANA) levels.

Methods

One hundred patients (83 women) with established SLE and a regular visit to the rheumatologist (March 2020 to January 2021) were included. All subjects donated blood and had done likewise prior to the pandemic. SARS-CoV-2 antibody isotypes (IgG, IgA, IgM) to the cell receptor-binding S1-spike outer envelope protein were detected by ELISA, and their neutralizing capacity was investigated. IgG-ANA were measured by multiplex technology.

Results

During the pandemic, 4% had PCR-confirmed infection but 36% showed SARS-CoV-2 antibodies of ≥1 isotype; IgA was the most common (30%), followed by IgM (9%) and IgG (8%). The antibodies had low neutralizing capacity and were detected also in prepandemic samples. Plasma albumin (p = 0.04) and anti-dsDNA (p = 0.003) levels were lower in patients with SARS-CoV-2 antibodies. Blood group, BMI, smoking habits, complement proteins, daily glucocorticoid dose, use of hydroxychloroquine, or self-reported coronavirus disease 2019 (COVID-19) symptoms (except fever, >38.5°C) did not associate with SARS-CoV-2 antibodies.

Conclusion

Our data from early 2021 indicate that a large proportion of Swedish SLE patients had serological signs of exposure to SARS-CoV-2 but apparently with a minor impact on the SLE course. Use of steroids and hydroxychloroquine showed no distinct effects, and self-reported COVID-19-related symptoms correlated poorly with all antibody isotypes.

Usefulness of Clinical and Laboratory Criteria for Diagnosing Autoimmune Liver Disease among Patients with Systemic Lupus Erythematosus: An Observational Study

Abnormal liver function tests are frequently observed during follow-up of patients with systemic lupus erythematosus (SLE) but data on co-existence with autoimmune liver diseases (AILD) are scarce. This retrospective study aimed to describe the prevalence of autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) among well-characterized subjects with SLE. We also evaluated whether the presence of autoantibodies to complement protein 1q (C1q) and/or ribosomal P protein (anti-ribP) are, directly or inversely, associated with AIH, as proposed in some reports. The number of screened patients was 287 (86% females), and all cases were included in a regional Swedish cohort. Each subject of the study population met the 1982 American College of Rheumatology classification criteria and/or the Fries' diagnostic principle. By applying the simplified diagnostic AIH criteria combined with persistent transaminasemia, 40 (13.9%) cases reached at least "probable AIH". However, merely 8 of these had been diagnosed with AIH (overall AIH prevalence 2.8%). Neither anti-C1q nor anti-ribP associated significantly with AIH. By applying the recent PBC guidelines, 6 (2.1%) cases were found, but only 3 of them had actually been diagnosed with PBC and one additional subject was not identified by the guidelines (overall PBC prevalence 1.4%). Compared to prevalence data from the general Swedish population, both AIH and PBC were highly overrepresented in our study population. The sensitivity of the diagnostic AIH criteria was impeccable but the specificity was less impressive, mainly due to positive ANA and hypergammaglobulinemia. Based on our findings, among subjects with SLE, the AIH criteria are less useful and liver biopsy combined with detection of other AILD-associated autoantibodies should be performed.

Longitudinal Analysis of Anti-cardiolipin and Anti-β2-glycoprotein-I Antibodies in Recent-Onset Systemic Lupus Erythematosus: A Prospective Study in Swedish Patients

Background: Anti-phospholipid syndrome (APS) and systemic lupus erythematous (SLE) are autoimmune disorders that often co-occur. Anti-phospholipid antibodies (aPL) are typical of both conditions and may be associated with vascular events and pregnancy-related morbidities. Whereas, aPL-screening is mandatory for individuals with suspected SLE, the clinical value of longitudinal aPL analyses in established SLE is unclear.

Methods: We investigated the occurrence and variation of IgG/IgA/IgM anti-cardiolipin (aCL) and anti-β2-glycoprotein-I (anti-β2GPI) antibodies, using both the manufacturer's cut-off and a cut-off based on the 99th percentile of 400 apparently healthy donors, in recent-onset SLE. Furthermore, we evaluated the relationships between aPL levels and SLE/APS manifestations, as well as the pharmacotherapy. Patients with SLE who met validated classification criteria were included in this prospective study (N = 54). Samples were obtained at 0, 6, 12, 24, 36, 48, 60, 72, 84, and 96 months after SLE diagnosis.

Results: Depending on the cut-off applied, 61.1 or 44.4% showed a positive result for at least one aPL isotype or the lupus anticoagulant test over time. Median values for all six aPL isotypes numerically decreased from inclusion to last follow-up, but none of the isotypes met statistical significance. Seroconversion (from positive to negative, or the opposite direction) was occasionally seen for both aCL and anti-β2GPI. IgA and IgM anti-β2GPI were the most common isotypes, followed by IgM aCL. Presence of IgG aCL associated significantly with myocardial infarction and miscarriage, and IgG/IgA anti-β2GPI with miscarriage.

Conclusion: aPL were common during the first years of SLE. Even though the levels fluctuated over time, the patients tended to remain aPL positive or negative. Repeated aPL testing in the absence of new symptoms seems to be of uncertain value in patients with recent-onset SLE.

Case Report: Borrelia-DNA Revealed the Cause of Arthritis and Dermatitis During Treatment With Rituximab

Borrelia-specific antibodies in serum did not contribute to the diagnosis of Borrelia arthritis or Borrelia-associated dermatitis in a young woman with ongoing treatment with rituximab due to multiple sclerosis. The diagnosis was confirmed by the detection of Borrelia-DNA in a skin punch biopsy. The patient history did not reveal any tick exposure. She had suffered for several months from fluctuating pain and swelling of the right knee as well as skin involvement with redness and oedema around the ankle of the same leg. Monoarthritis was confirmed by a rheumatologist. Knee puncture was performed but the synovial fluid was only sufficient for microscopic examination of crystals. Neither monosodium urate crystals nor calcium pyrophosphate crystals were found. Borrelia serology in blood revealed borderline levels of immunoglobulin (Ig)M and IgG, respectively. Treatment with doxycycline resulted in resolution of the joint and skin manifestations within a month. This case highlights that Borrelia-specific antibody levels cannot be reliably interpreted in patients who have received B-cell depleting therapy. Under these circumstances, detection of the bacterial genome in different body fluids, such as in the skin, can be a useful complement to the diagnosis of Lyme disease. In this young female, the diagnosis would certainly have been further delayed without the detection of Borrelia-DNA in the skin.

Autoantibodies associated with primary biliary cholangitis are common among patients with systemic lupus erythematosus even in the absence of elevated liver enzymes

Knowledge of concomitant autoimmune liver diseases (AILD) is more detailed in primary Sjögren's syndrome (pSS) compared to systemic lupus erythematosus (SLE). Herein, the prevalence of autoantibodies associated with autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) was investigated in stored sera from patients with SLE (n = 280) and pSS (n = 114). Antibodies against mitochondria (AMA), liver-kidney microsomal (LKM) antigen, smooth muscle (SMA) and anti-nuclear antibodies (ANA) were analysed with immunofluorescence microscopy. In addition, AILD-associated autoantibodies were tested with immunoblot. Prior to sampling, eight SLE (2·9%) and three pSS (2·6%) cases were diagnosed with AILD. Among SLE-cases without known AILD (n = 272), 26 (9·6%) had PBC-associated autoantibodies, 15 (5·5%) AIH-associated autoantibodies (excluding ANA) and one serological overlap. Most subjects with PBC-associated autoantibodies had liver enzymes within reference limits (22 of 27, 81%) or mild laboratory cholestasis (two of 27, 7·4%), while one fulfilled the diagnostic PBC-criteria. AMA-M2 detected by immunoblot was the most common PBC-associated autoantibody in SLE (20 of 272, 7·4%). The prevalence of SMA (4·4%) was comparable with a healthy reference population, but associated with elevated liver enzymes in four of 12 (25%), none meeting AIH-criteria. The patient with combined AIH/PBC-serology had liver enzymes within reference limits. Among pSS cases without known AILD (n = 111), nine (8·1%) had PBC-associated, 12 (10·8%) AIH-associated autoantibodies and two overlapped. PBC-associated autoantibodies were found as frequently in SLE as in pSS but were, with few exceptions, not associated with laboratory signs of liver disease. Overall, AILD-associated autoantibodies were predominantly detected by immunoblot and no significant difference in liver enzymes was found between AILD autoantibody-negative and -positive patients.

Induction of aquaporin 4-reactive antibodies in Lewis rats immunized with aquaporin 4 mimotopes

Most cases of neuromyelitis optica spectrum disorders (NMOSD) harbor pathogenic autoantibodies against the water channel aquaporin 4 (AQP4). Binding of these antibodies to AQP4 on astrocytes initiates damage to these cells, which culminates in the formation of large tissue destructive lesions in the central nervous system (CNS). Consequently, untreated patients may become permanently blind or paralyzed. Studies on the induction and breakage of tolerance to AQP4 could be of great benefit for NMOSD patients. So far, however, all attempts to create suitable animal models by active sensitization have failed. We addressed this challenge and identified peptides, which mimic the conformational AQP4 epitopes recognized by pathogenic antibodies of NMOSD patients. Here we show that these mimotopes can induce the production of AQP4-reactive antibodies in Lewis rats. Hence, our results provide a conceptual framework for the formation of such antibodies in NMOSD patients, and aid to improve immunization strategies for the creation of animal models suitable for tolerance studies in this devastating disease.

Metabolic Dysfunction in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Not Due to Anti-mitochondrial Antibodies

Metabolic profiling studies have recently indicated dysfunctional mitochondria in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). This includes an impaired function of pyruvate dehydrogenase complex (PDC), possibly driven by serum factor(s), which leads to inadequate adenosine triphosphate generation and excessive lactate accumulation. A reminiscent energy blockade is likely to occur in primary biliary cholangitis (PBC), caused by anti-PDC autoantibodies, as recently proposed. PBC is associated with fatigue and post-exertional malaise, also signifying ME/CFS. We herein have investigated whether ME/CFS patients have autoreactive antibodies that could interfere with mitochondrial function. We found that only 1 of 161 examined ME/CFS patients was positive for anti-PDC, while all PBC patients (15/15) presented significant IgM, IgG, and IgA anti-PDC reactivity, as previously shown. None of fibromyalgia patients (0/14), multiple sclerosis patients (0/29), and healthy blood donors (0/44) controls showed reactivities. Anti-mitochondrial autoantibodies (inner and outer membrane) were negative in ME/CFS cohort. Anti-cardiolipin antibody levels in patients did not differ significantly from healthy blood donors. In conclusion, the impaired mitochondrial/metabolic dysfunction, observed in ME/CFS, cannot be explained by presence of circulating autoantibodies against the tested mitochondrial epitopes.

Complement activation in cerebrospinal fluid in clinically isolated syndrome and early stages of relapsing remitting multiple sclerosis

To assess if markers of complement activation are associated with disease activity, C1q, C3, C3a and sC5b-9 levels in plasma and cerebrospinal fluid (CSF) were determined in 41 patients with clinically isolated syndrome (CIS) or remitting multiple sclerosis (RRMS), in a prospective longitudinal four-year cohort study. C1q in CSF (CSF-C1q) was significantly higher in patients than in controls. Baseline CSF-C1q and CSF-C3a correlated with several neuroinflammatory markers and neurofilament light chain levels. Baseline CSF-C3a correlated with the number of T2 lesions at baseline and new T2 lesions during follow-up. Baseline CSF-C3a was also significantly higher in patients with (n = 21) than in patients without (n = 20) signs of disease activity according to the NEDA-3 concept during one year of follow-up (p ≤ .01) Study results support that complement activation is involved in MS pathophysiology and that CSF-C3a carries prognostic information.

Celiac disease and complement activation in response to Streptococcus pneumoniae

Individuals with celiac disease (CD) are at increased risk of invasive pneumococcal disease (IPD). The aim of this study was to explore whether the complement response to Streptococcus pneumoniae differed according to CD status, and could serve as an explanation for the excess risk of IPD in CD. Twenty-two children with CD and 18 controls, born 1999-2008, were included at Kalmar County Hospital, Sweden. The degree of complement activation was evaluated by comparing levels of activation products C3a and sC5b-9 in plasma incubated for 30 min with Streptococcus pneumoniae and in non-incubated plasma. Complement analyses were performed with enzyme-linked immunosorbent assay (ELISA). Pneumococcal stimulation caused a statistically significant increase in C3a as well as sC5b-9 in both children with CD and controls but there was no difference in response between the groups. After incubation, C3a increased on average 4.6 times and sC5b-9 22 times in both the CD and the control group (p = 0.497 and p = 0.724 respectively).Conclusion: Complement response to Streptococcus pneumoniae seems to be similar in children with and without CD and is thus unlikely to contribute to the increased susceptibility to invasive pneumococcal disease in CD.What is Known:• An excess risk of pneumococcal infections has been demonstrated in individuals with celiac disease.• Infectious complications can depend on hyposplenism but alternative mechanisms are sparsely examined.What is New:• Complement activation in response to Streptococcus pneumoniae was examined in children with and without celiac disease but no differences could be demonstrated.

Longitudinal anti-nuclear antibody (ANA) seroconversion in systemic lupus erythematosus: a prospective study of Swedish cases with recent-onset disease

Serum immunoglobulin (Ig)G anti-nuclear antibodies (ANA) detected by indirect immunofluorescence (IF) microscopy remains a hallmark of systemic lupus erythematosus (SLE). Whether or not IF-ANA status varies over time is controversial. We therefore designed a prospective study with longitudinal follow-up of patients with recent-onset SLE. The study population consisted of 54 recently diagnosed SLE cases, all meeting the 1982 American College of Rheumatology (ACR) and/or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria. Clinical follow-up data, including disease activity, organ damage and sera, were collected from clinical onset of SLE and onwards, in most cases yearly (0-96 months). IF-ANA was analysed on human epithelial cells-2 (HEp-2) cells and categorized regarding staining patterns. Using an addressable laser bead assay (FIDIS™ Connective profile), we measured IgG-ANA fine specificities against Ro52/SSA, Ro60/SSA, Sjögren's syndrome type B antigen (La/SSB), Smith antigen (Sm), Smith antigen/ribonucleoprotein (Sm/RNP), U1 RNP (U1RNP), dsDNA, ribosomal-P protein and histone. At baseline, all patients were judged ANA-positive at an abnormal titre corresponding to the 95th percentile of healthy blood donors, but seven of 54 patients (13%) lost ANA-positivity over time. Homogeneous (AC-1; 46%) and speckled (AC-4 or 5; 31%) were the most frequently observed patterns at inclusion, whereas 7% switched pattern at least once during follow-up. Established associations between ANA fine specificities and clinical data were confirmed. Levels of anti-Sm/RNP, but not of anti-dsDNA, correlated with clinical disease activity [modified SLE disease activity 2000 (mSLEDAI-2K)]. Our data indicate that a considerable proportion of Swedish patients with SLE lose ANA-positivity over time, whereas consistent staining patterns were frequent. The clinical and mechanistic relevance of ANA seroconversion remains uncertain. Further prospective evaluations in larger SLE populations with more diverse ethnicities are warranted.

P14.09 INITIAL GLOBAL SYMPTOMS IN GLIOBLASTOMA ARE OFTEN MISINTERPRETED AND ASSOCIATED WITH SHORTER SURVIVAL

BACKGROUND

A seizure as the only symptom before diagnosing glioblastoma improves survival rate. Apart from seizures, the main presenting symptom of glioma in adults is cognitive dysfunction. The effect of generalized symptoms or loss of function on lead times and survival of glioblastoma has not been studied. Generalized symptoms include cognitive dysfunction, headache, dizziness and fatigue. Loss of function comprise paresis, sensory deficit and speech aberrations. The objective of this study was to evaluate the influence of different presenting symptoms regarding health care level, lead times and survival.

MATERIAL AND METHOD

Medical case notes regarding 189 consecutive patients with histopathologically verified glioblastoma, were reviewed for information about the date and level of care of the first medical appointment, presenting symptom/s, and date of the diagnostic radiology. The extent of surgery was noted. Data on oncologic treatment was retrieved. Summary statistics were provided for patient demographics and treatment factors. The estimates of overall survival were calculated using the Kaplan-Meier method. Survival time was calculated from the date of radiological diagnosis.

RESULTS

The majority of patients (66%) presented with generalized symptoms, which significantly reduced survival compared to not having generalized symptoms (mean survival 10.5 months vs 19.9 months, p=0.001). The most common generalized symptom was cognitive dysfunction which further reduced survival (mean survival 9.0 months, p=0.0001). Among the different cognitive aberrations, personality change and memory impairment were associated with a significantly poorer survival, (mean survival 7.9 months, p=0.015 and 8.0 months p=0.010, respectively). Disorientation also significantly reduced survival (mean survival 8.2 months p=0.001). Presenting with loss of function (58%) did not influence survival (mean survival 12.3 months). 32% of patients with an epileptic seizure as initial symptom had significantly prolonged survival compared to those not having an epileptic seizure (mean 18.9 months vs 11.0 months p=0.002). When comparing focal and secondary generalized epileptic seizures, focal epileptic seizures were more favorable. The first medical appointment was evenly distributed between primary health care and the emergency units. 8.4% of patients had multiple contacts in primary health care without being admitted to radiology or specialized care. All but one of them presented with generalized symptoms.

CONCLUSION

Glioblastoma patients presenting with generalized symptoms such as cognitive dysfunction are difficult to identify and have significantly poorer survival than other glioblastoma patients. Patients presenting with an epileptic seizure have shorter leadtime and longer survival.

Fcγ-receptor polymorphisms associated with clinical symptoms in patients with immunoglobulin G subclass deficiency

BACKGROUND

Immunoglobulin G subclass deficiencies (IgGsd) are associated with recurrent respiratory tract infections. Immunoglobulin substitution therapy may be needed to prevent chronic lung tissue damage but tools for identifying the patients that will benefit from this treatment are still insufficient. Some FcγR polymorphisms seem to predispose for an increased risk for infections. In this study we wanted to evaluate if the FcγR-profile differs between individuals with IgGsd and a control population.

METHODS

Single nucleotide polymorphisms (SNPs) of FcγRIIa, FcγRIIIa and FcγRIIc in 36 IgGsd patients and 192 controls with similar sex and geographical distribution were analyzed by TaqMan allelic discrimination assay or Sanger sequencing.

RESULTS

In the IgGsd-group, homozygous frequency for FcγRIIa-R/R131 (low-binding capacity isoform) was higher (p = .03) as well as for non-classical FcγRIIc-ORF (p = .03) and classical FcγRIIc-ORF tended (p = .07) to be more common compared to the controls. There was no difference between the groups regarding FcγRIIIa.

CONCLUSION

The gene for classical FcγRIIc-ORF tended to be more frequent in individuals with immunoglobulin G subclass deficiency and the genes for non-classical FcγRIIc-ORF as well as low-binding capacity receptor FcγRIIa-R/R131 were more frequent. Further studies on the FcγR polymorphisms may pave way for identifying individuals that will benefit from immunoglobulin substitution.

Neurofilament levels, disease activity and brain volume during follow-up in multiple sclerosis

Background

There is a need for clinically useful biomarkers of disease activity in clinically isolated syndrome (CIS) and relapsing remitting MS (RRMS). The aim of this study was to assess the correlation between neurofilament light chain (NFL) in cerebrospinal fluid (CSF) and serum and the relationship between NFL and other biomarkers, subsequent disease activity, and brain volume loss in CIS and RRMS.

Methods

A panel of neurodegenerative and neuroinflammatory markers were analyzed in repeated CSF samples from 41 patients with CIS or RRMS in a prospective longitudinal cohort study and from 22 healthy controls. NFL in serum was analyzed using a single-molecule array (Simoa) method. “No evidence of disease activity-3” (NEDA-3) status and brain volume (brain parenchymal fraction calculated using SyMRI®) were recorded during 4 years of follow-up.

Results

NFL levels in CSF and serum correlated significantly (all samples, n = 63, r 0.74, p < 0.001), but CSF-NFL showed an overall stronger association profile with NEDA-3 status, new T2 lesions, and brain volume loss. CSF-NFL was associated with both new T2 lesions and brain volume loss during follow-up, whereas CSF-CHI3L1 was associated mainly with brain volume loss and CXCL1, CXCL10, CXCL13, CCL22, and MMP-9 were associated mainly with new T2 lesions.

Conclusions

Serum and CSF levels of NFL correlate, but CSF-NFL predicts and reflects disease activity better than S-NFL. CSF-NFL levels are associated with both new T2 lesions and brain volume loss. Our findings further add to the accumulating evidence that CSF-NFL is a clinically useful biomarker in CIS and RRMS and should be considered in the expanding NEDA concept. CSF-CXCL10 and CSF-CSF-CHI3L1 are potential markers of disease activity and brain volume loss, respectively.

Electronic supplementary material

The online version of this article (10.1186/s12974-018-1249-7) contains supplementary material, which is available to authorized users.

Increased prevalence of celiac disease in idiopathic inflammatory myopathies

OBJECTIVES

Idiopathic inflammatory myopathies (IIM) are often associated with other immune-mediated diseases or malignancy. Some studies have reported a high frequency of celiac disease in IIM. The aim of this study was to investigate the prevalence of celiac disease, systemic inflammatory diseases, and malignancy in a cohort of IIM patients, and estimate the incidence of IIM in the county of Östergötland, Sweden.

MATERIAL AND METHODS

We reviewed medical records and analyzed sera from 106 patients, fulfilling pathological criteria of inflammatory myopathy, for the presence of IgA antibodies against endomysium and gliadin. Antibody-positive patients were offered further investigation with small bowel biopsy or investigation for the presence of antibodies against antitissue transglutaminase (t-TG). The patients were classified according to Bohan and Peter or Griggs criteria. The presence of celiac disease, systemic inflammatory, and malignant diseases was documented.

RESULTS

Four of 88 patients classified as IIM (4.5%) had biopsy-confirmed celiac disease, which is higher than the prevalence in the general population, detected with a similar screening procedure (0.53%). Thirty-three patients (38%) had a systemic inflammatory disease and five (5.7%) a malignancy. The incidence of confirmed IIM in the county of Östergötland was 7.3 per million/year.

CONCLUSIONS

The results highlight the high frequency of associated inflammatory and malignant diseases and confirm an increased prevalence of celiac disease in IIM.

Neurofilament light chain in cerebrospinal fluid and prediction of disease activity in clinically isolated syndrome and relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

Improved biomarkers are needed to facilitate clinical decision-making and as surrogate endpoints in clinical trials in multiple sclerosis (MS). We assessed whether neurodegenerative and neuroinflammatory markers in cerebrospinal fluid (CSF) at initial sampling could predict disease activity during 2 years of follow-up in patients with clinically isolated syndrome (CIS) and relapsing-remitting MS.

METHODS

Using multiplex bead array and enzyme-linked immunosorbent assay, CXCL1, CXCL8, CXCL10, CXCL13, CCL20, CCL22, neurofilament light chain (NFL), neurofilament heavy chain, glial fibrillary acidic protein, chitinase-3-like-1, matrix metalloproteinase-9 and osteopontin were analysed in CSF from 41 patients with CIS or relapsing-remitting MS and 22 healthy controls. Disease activity (relapses, magnetic resonance imaging activity or disability worsening) in patients was recorded during 2 years of follow-up in this prospective longitudinal cohort study.

RESULTS

In a logistic regression analysis model, NFL in CSF at baseline emerged as the best predictive marker, correctly classifying 93% of patients who showed evidence of disease activity during 2 years of follow-up and 67% of patients who did not, with an overall proportion of 85% (33 of 39 patients) correctly classified. Combining NFL with either neurofilament heavy chain or osteopontin resulted in 87% overall correctly classified patients, whereas combining NFL with a chemokine did not improve results.

CONCLUSIONS

This study demonstrates the potential prognostic value of NFL in baseline CSF in CIS and relapsing-remitting MS and supports its use as a predictive biomarker of disease activity.

The impact of adjusted work conditions and disease-modifying drugs on work ability in multiple sclerosis

Background:

Multiple sclerosis (MS) is a neurological disorder that causes significantly reduced ability to work, and the Expanded Disability Status Scale (EDSS) is one of the main predictors for reduced work ability.

Objectives:

To investigate how work requirements, flexible work conditions and disease-modifying drugs (DMDs) influence the work ability in relation to different EDSS grades in two MS populations.

Methods:

Work ability was studied in two MS populations: one in the southern and one in the northern part of Sweden, both demographically similar. In the latter population, more active work-promoting interventions have been practised and second-generation DMDs have been widely used from the onset of disease for several years.

Results:

The proportion of MS patients who participated in the workforce or studied was significantly higher in the northern compared with the southern population ( p < 0.001). The employees in the northern population had significantly lower requirements, greater adapted work conditions and were able to work more hours per week. Higher EDSS was associated with lower reduction in number of worked hours per week in the northern population ( p = 0.042).

Conclusion:

Our data indicated that treatment strategy and adjusted work conditions have impact on work ability in MS.

Cerebrospinal fluid levels of neurofilament and tau correlate with brain atrophy in natalizumab-treated multiple sclerosis

BACKGROUND AND PURPOSE

Brain atrophy is related to clinical deterioration in multiple sclerosis (MS) but its association with intrathecal markers of inflammation or neurodegeneration is unclear. Our aim was to investigate whether cerebrospinal fluid (CSF) markers of inflammation or neurodegeneration are associated with brain volume change in natalizumab-treated MS and whether this change is reflected in non-lesional white matter metabolites.

METHODS

About 25 patients with natalizumab-treated MS were followed for 3 years with assessment of percentage brain volume change (PBVC) and absolute quantification of metabolites with proton magnetic resonance spectroscopy (¹ H MRS). Analyses of inflammatory [interleukin 1β (IL-1β), IL-6, C-X-C motif chemokine 8 (CXCL8), CXCL10, CXCL11, C-C motif chemokine 22] and neurodegenerative [neurofilament light protein (NFL), glial fibrillary acidic protein, myelin basic protein, tau proteins] markers were done at baseline and 1-year follow-up.

RESULTS

The mean decline in PBVC was 3% at the 3-year follow-up, although mean ¹ H MRS metabolite levels in non-lesional white matter were unchanged. CSF levels of NFL and tau at baseline correlated negatively with PBVC over 3 years (r = -0.564, P = 0.012, and r = -0.592, P = 0.010, respectively).

CONCLUSIONS

A significant 3-year whole-brain atrophy was not reflected in mean metabolite change of non-lesional white matter. In addition, our results suggest that CSF levels of NFL and tau correlate with brain atrophy development and may be used for evaluating treatment response in inflammatory active MS.

Aquaporin 4-specific T cells and NMO-IgG cause primary retinal damage in experimental NMO/SD

Neuromyelitis optica/spectrum disorder (NMO/SD) is a severe, inflammatory disease of the central nervous system (CNS). In the majority of patients, it is associated with the presence of pathogenic serum autoantibodies (the so-called NMO-IgGs) directed against the water channel aquaporin 4 (AQP4), and with the formation of large, astrocyte-destructive lesions in spinal cord and optic nerves. A large number of recent studies using optical coherence tomography (OCT) demonstrated that damage to optic nerves in NMO/SD is also associated with retinal injury, as evidenced by retinal nerve fiber layer (RNFL) thinning and microcystic inner nuclear layer abnormalities. These studies concluded that retinal injury in NMO/SD patients results from secondary neurodegeneration triggered by optic neuritis.However, the eye also contains cells expressing AQP4, i.e., Müller cells and astrocytes in the retina, epithelial cells of the ciliary body, and epithelial cells of the iris, which raised the question whether the eye can also be a primary target in NMO/SD. Here, we addressed this point in experimental NMO/SD (ENMO) induced in Lewis rat by transfer of AQP4268-285-specific T cells and NMO-IgG.We show that these animals show retinitis and subsequent dysfunction/damage of retinal axons and neurons, and that this pathology occurs independently of the action of NMO-IgG. We further show that in the retinae of ENMO animals Müller cell side branches lose AQP4 reactivity, while retinal astrocytes and Müller cell processes in the RNFL/ganglionic cell layers are spared. These changes only occur in the presence of both AQP4268-285-specific T cells and NMO-IgG.Cumulatively, our data show that damage to retinal cells can be a primary event in NMO/SD.

Circulating cartilage oligomeric matrix protein in juvenile idiopathic arthritis

OBJECTIVES

Raised serum cartilage oligomeric matrix protein (sCOMP) has been reported to predict erosive disease in early rheumatoid arthritis (RA). In juvenile idiopathic arthritis (JIA), subnormal sCOMP levels have been associated with ongoing inflammation and growth retardation. In this study we aimed to assess sCOMP, C-reactive protein (CRP), and insulin-like growth factor (IGF)-1 in children/adolescents with JIA and in referents.

METHOD

We enrolled 52 JIA patients at planned outpatient visits and 54 inpatients with ongoing infection ('infection referents'). A total of 120 referents testing negative for immunoglobulin (Ig)E-mediated allergy ('IgE referents') served as controls. All serum samples were analysed for COMP, IGF-1, and CRP.

RESULTS

The average sCOMP level was highest among the IgE referents and lowest among the infection referents. In the JIA patients, the level of sCOMP was not associated with the level of CRP or with clinical signs of disease activity.

CONCLUSIONS

The results of this study do not support routine clinical analysis of sCOMP levels in patients with JIA.

Experimental Neuromyelitis Optica Induces a Type I Interferon Signature in the Spinal Cord

Neuromyelitis optica (NMO) is an acute inflammatory disease of the central nervous system (CNS) which predominantly affects spinal cord and optic nerves. Most patients harbor pathogenic autoantibodies, the so-called NMO-IgGs, which are directed against the water channel aquaporin 4 (AQP4) on astrocytes. When these antibodies gain access to the CNS, they mediate astrocyte destruction by complement-dependent and by antibody-dependent cellular cytotoxicity. In contrast to multiple sclerosis (MS) patients who benefit from therapies involving type I interferons (I-IFN), NMO patients typically do not profit from such treatments. How is I-IFN involved in NMO pathogenesis? To address this question, we made gene expression profiles of spinal cords from Lewis rat models of experimental neuromyelitis optica (ENMO) and experimental autoimmune encephalomyelitis (EAE). We found an upregulation of I-IFN signature genes in EAE spinal cords, and a further upregulation of these genes in ENMO. To learn whether the local I-IFN signature is harmful or beneficial, we induced ENMO by transfer of CNS antigen-specific T cells and NMO-IgG, and treated the animals with I-IFN at the very onset of clinical symptoms, when the blood-brain barrier was open. With this treatment regimen, we could amplify possible effects of the I-IFN induced genes on the transmigration of infiltrating cells through the blood brain barrier, and on lesion formation and expansion, but could avoid effects of I-IFN on the differentiation of pathogenic T and B cells in the lymph nodes. We observed that I-IFN treated ENMO rats had spinal cord lesions with fewer T cells, macrophages/activated microglia and activated neutrophils, and less astrocyte damage than their vehicle treated counterparts, suggesting beneficial effects of I-IFN.

Improved working ability in a contemporary MS population compared with a historic non-treated MS population in the same geographic area of Sweden

Background

Multiple sclerosis (MS) often causes a reduced ability to work. Improved disease control as well as adjustment of working conditions may improve work ability in MS.

Objectives

The objective of this article is to compare the degree of sickness absence in two MS populations that either have or have not received disease-modifying drug (DMD) treatments or active work-promoting measures.

Methods

We investigated the occurrence of sickness absence in MS patients living in Västerbotten County, Sweden, in 2013, in which the majority of MS patients receive DMD treatment. The result was compared with a previous survey in the same area during a period when no DMD was available and no work-promoting measures for MS patients were practiced.

Results

The proportion of MS patients active in the labor market or studying increased from 38% to 70% in the contemporary compared with the historic population (p < 0.001). The proportion of MS patients with a full-time disability pension decreased from 27% to 12% (p < 0.001). There was a significant decrease of sickness absence in several individual EDSS grades.

Conclusions

Our data indicate that treatment with DMDs combined with active work-promoting measures lead to improved work ability in MS.

Four Anti-dsDNA Antibody Assays in Relation to Systemic Lupus Erythematosus Disease Specificity and Activity

OBJECTIVE

Analysis of antibodies against dsDNA is an important diagnostic tool for systemic lupus erythematosus (SLE), and changes in anti-dsDNA antibody levels are also used to assess disease activity. Herein, 4 assays were compared with regard to SLE specificity, sensitivity, and association with disease activity variables.

METHODS

Cross-sectional sera from 178 patients with SLE, of which 11 were followed consecutively, from a regional Swedish SLE register were analyzed for immunoglobulin G (IgG) anti-dsDNA by bead-based multiplex assay (FIDIS; Theradig), fluoroenzyme-immunoassay (EliA; Phadia/Thermo Fisher Scientific), Crithidia luciliae immunofluorescence test (CLIFT; ImmunoConcepts), and line blot (EUROLINE; Euroimmun). All patients with SLE fulfilled the 1982 American College of Rheumatology and/or the 2012 Systemic Lupus International Collaborating Clinics (SLICC-12) classification criteria. Healthy individuals (n = 100), patients with rheumatoid arthritis (n = 95), and patients with primary Sjögren syndrome (n = 54) served as controls.

RESULTS

CLIFT had the highest SLE specificity (98%) whereas EliA had the highest sensitivity (35%). When cutoff levels for FIDIS, EliA, and EUROLINE were adjusted according to SLICC-12 (i.e., double the reference limit when using ELISA), the specificity and sensitivity of FIDIS was comparable to CLIFT. FIDIS and CLIFT also showed the highest concordance (84%). FIDIS performed best regarding association with disease activity in cross-sectional and consecutive samples. Fisher's exact test revealed striking differences between methods regarding associations with certain disease phenotypes.

CONCLUSION

CLIFT remains a good choice for diagnostic purposes, but FIDIS performs equally well when the cutoff is adjusted according to SLICC-12. Based on results from cross-sectional and consecutive analyses, FIDIS can also be recommended to monitor disease activity.

Does the frequency of respiratory tract infections help to identify humoral immunodeficiencies in a primary health-care cohort?

BACKGROUND

Primary immune deficiency (PID) due to humoral defects is associated with recurrent respiratory tract infections (RTIs). Reliable clinical warning signs of PID would facilitate early diagnosis and thereby reduce long-term complications. The aim of the present study was to evaluate the accuracy of the warning sign, 'four or more antibiotic-treated RTIs annually for 3 or more consecutive years,' for detecting PID among adults in a primary health-care setting.

METHODS

Fifty-three cases with 'four or more antibiotic-treated RTIs annually for 3 or more consecutive years' were selected from a Swedish primary health-care registry of RTIs. In addition, 66 age- and sex-matched controls were selected having a maximum of one antibiotic-treated RTI during the period covered by the study. Levels of immunoglobulin (Ig) IgG, IgA, IgM, IgG subclasses, and IgG antibodies against Haemophilus influenzae and Streptococcus pneumoniae as well as the inflammatory markers, C-reactive protein, interleukin (IL)-6 and IL-8 were determined.

RESULTS

IgG subclass deficiencies (IgGsd) were found in 5/53 (9.4%) of the cases and in 7/66 (10.6%) controls. The most frequent deficiency was IgG3sd and this was found in three participants in the case group and seven in the control group. The mean level of IgG3 was lower in the control group (p = 0.02). The mean level of IL-8 was lower in the case group (p = 0.02).

CONCLUSION

The results show that physicians working in primary health care cannot solely rely on the frequency of antibiotic-treated RTIs as a warning sign for the detection of common humoral immune deficiencies.

Serological assessment for celiac disease in IgA deficient adults

PURPOSE

Selective immunoglobulin A deficiency is the most common primary immunodeficiency disorder that is strongly overrepresented among patients with celiac disease (CD). IgG antibodies against tissue transglutaminase (tTG) and deamidated gliadin peptides (DGP) serve as serological markers for CD in IgA deficient individuals, although the diagnostic value remains uncertain. The aim of this study was to investigate the prevalence of these markers in a large cohort of IgA deficient adults with confirmed or suspected CD and relate the findings to gluten free diet.

METHODS

Sera from 488,156 individuals were screened for CD in seven Swedish clinical immunology laboratories between 1998 and 2012. In total, 356 out of 1,414 identified IgA deficient adults agreed to participate in this study and were resampled. Forty-seven IgA deficient blood donors served as controls. Analyses of IgG antibodies against tTG and DGP as well as HLA typing were performed and a questionnaire was used to investigate adherence to gluten free diet. Available biopsy results were collected.

RESULTS

Out of the 356 IgA deficient resampled adults, 67 (18.8%) were positive for IgG anti-tTG and 79 (22.2%) for IgG anti-DGP, 54 had biopsy confirmed CD. Among the 47 IgA deficient blood donors, 4 (9%) were positive for IgG anti-tTG and 8 (17%) for anti-DGP. Four were diagnosed with biopsy verified CD, however, 2 of the patients were negative for all markers. Sixty-eight of 69 individuals with positive IgG anti-tTG were HLA-DQ2/DQ8 positive whereas 7 (18.9%) of the 37 individuals positive for IgG anti-DGP alone were not.

CONCLUSIONS

IgG anti-tTG seems to be a more reliable marker for CD in IgA deficient adults whereas the diagnostic specificity of anti-DGP appears to be lower. High levels of IgG antibodies against tTG and DGP were frequently found in IgA deficient adults despite adhering to gluten free diet.

Reduced sick leave in multiple sclerosis after one year of natalizumab treatment. A prospective ad hoc analysis of the TYNERGY trial

Background:

In a retrospective study, we have previously shown that work ability was improved after the initiation of natalizumab treatment in relapsing–remitting multiple sclerosis (RRMS). In another prospective trial (TYNERGY) the effect on MS-related fatigue was evaluated after 12 months of treatment with natalizumab. A comprehensive Capacity for Work Questionnaire (CWQ) was used to collect data regarding number of working hours and sickness absence. The predefined intention-to-treat analysis regarding work ability did not, however, show significant results.

Objectives:

The objective of this paper is to assess the amount of sick leave in RRMS before and after one year of natalizumab treatment and correlate it to fatigue and walking ability.

Methods:

This is a post-hoc analysis of the complete data from the CWQ used in the TYNERGY trial.

Results:

MS patients receiving sickness benefit before start of treatment reduced their sickness benefit by an absolute change of 33% after one year of natalizumab treatment. Younger age and improvement of walking ability correlated significantly with reduction of sick leave.

Conclusions:

This ad-hoc analysis of prospectively collected data supported our previous retrospective study and thus indicates a positive relationship between natalizumab treatment and improvement in work ability.

Increased B cell and cytotoxic NK cell proportions and increased T cell responsiveness in blood of natalizumab-treated multiple sclerosis patients

Background

Changes in the blood lymphocyte composition probably both mediate and reflect the effects of natalizumab treatment in multiple sclerosis, with implications for treatment benefits and risks.

Methods

A broad panel of markers for lymphocyte populations, including states of activation and co-stimulation, as well as functional T cell responses to recall antigens and mitogens, were assessed by flow cytometry in 40 patients with relapsing multiple sclerosis before and after one-year natalizumab treatment.

Results

Absolute numbers of all major lymphocyte populations increased after treatment, most markedly for NK and B cells. The fraction of both memory and presumed regulatory B cell subsets increased, as did CD3^-CD56^dim cytotoxic NK cells, whereas CD3^-CD56^bright regulatory NK cells decreased. The increase in cell numbers was further associated with a restored T cell responsiveness to recall antigens and mitogens in functional assays.

Conclusions

Our data confirms that natalizumab treatment increases the number of lymphocytes in blood, likely mirroring the expression of VLA-4 being highest on NK and B cells. This finding supports reduction of lymphocyte extravasation as a main mode of action, although the differential effects on subpopulation composition suggests that cell-signalling may also be affected. The systemic increase in T cell responsiveness reflects the increase in numbers, and while augmenting anti-infectious responses systemically, localized responses may become correspondingly decreased.

Intraepithelial lymphocyte distribution differs between the bulb and the second part of duodenum

BACKGROUND

Evaluation of intraepithelial duodenal lymphocytosis (IDL) is important in celiac disease (CD). There is no established cut-off value for increased number of IELs in the bulb.We therefore investigated the relation between IEL counts in the bulb and duodenal specimens in non-celiac subjects.

METHODS

The number of CD3+ IELs was determined in specimens from the second part of the duodenum and from the bulb in 34 non-celiac subjects. The numbers of IELs in the villus tip and sides were counted and the quotient tip/side was calculated. HLA DQ2/DQ8 and serum antibodies against transglutaminase were analysed.

RESULTS

The mean number of IELs per 100 enterocytes (95% CI) in specimens was 14.7 (11.8-17.6) in the bulb, and 21.2 (17.0-25.5) in the second part of the duodenum (p<0.01). There was no difference in IEL count or distribution comparing patients carrying or lacking HLA DQ2/DQ8.

CONCLUSIONS

IEL count in non-celiac, HLA DQ2/DQ8 positive or negative patients is significantly lower in the bulb than in the second part of the duodenum. These findings implicate that the site of biopsy should be taken into account when considering duodenal lymphocytosis.

IgA antibodies against tissue transglutaminase, endomysium and gliadin in idiopathic polyneuropathy

OBJECTIVES

To study the prevalence of antibodies of IgA class against tissue transglutaminase (tTG), endomysium (EMA) and gliadin (AGA) in patients with chronic idiopathic axonal polyneuropathy (CIAP) and to characterize the patients clinically and neurophysiologically.

METHODS

Of 182 patients, 126 patients agreed to blood sampling. Sera were analysed by ELISAs detecting anti-tTG and AGA, whereas EMA was analysed by indirect immunofluorescence (IF) microscopy. Gastrointestinal symptoms were assessed by data from medical records and patient interviews.

RESULTS

Nine of 126 patients (7%) were seropositive in at least one test (five with positive anti-tTG and/or EMA and four with positive AGA only). One patient with elevated levels of all specificities had laboratory signs of malabsorption and gastrointestinal complaints with abdominal pain and diarrhoea.

CONCLUSIONS

Elevated levels of IgA-AGA were slightly more frequent in patients with CIAP (4%) compared to 2.5% in 1866 healthy blood donors. Highly specific serological markers indicative of coeliac disease (CD) (anti-tTG and EMA) were somewhat more common in our patients with CIAP (4%) than expected from normal reference values and from studies of the prevalence of CD in the general population. Even though these findings may indicate a relationship, the aetiological importance is unclear.

Time to secondary progression in patients with multiple sclerosis who were treated with first generation immunomodulating drugs

BACKGROUND

It is currently unknown whether early immunomodulatory treatment in relapsing-remitting MS (RRMS) can delay the transition to secondary progression (SP).

OBJECTIVE

To compare the time interval from onset to SP in patients with RRMS between a contemporary cohort, treated with first generation disease modifying drugs (DMDs), and a historical control cohort.

METHODS

We included a cohort of contemporary RRMS patients treated with DMDs, obtained from the Swedish National MS Registry (disease onset between 1995-2004, n = 730) and a historical population-based incidence cohort (onset 1950-64, n = 186). We retrospectively analyzed the difference in time to SP, termed the "period effect" within a 12-year survival analysis, using Kaplan-Meier and Cox regression analysis.

RESULTS

We found that the "period" affected the entire severity spectrum. After adjusting for onset features, which were weaker in the contemporary material, as well as the therapy initiation time, the DMD-treated patients still exhibited a longer time to SP than the controls (hazard ratios: men, 0.32; women, 0.53).

CONCLUSION

Our results showed there was a longer time to SP in the contemporary subjects given DMD. Our analyses suggested that this effect was not solely driven by the inclusion of benign cases, and it was at least partly due to the long-term immunomodulating therapy given.

Association between change in normal appearing white matter metabolites and intrathecal inflammation in natalizumab-treated multiple sclerosis

Background

Multiple sclerosis (MS) is associated not only with focal inflammatory lesions but also diffuse pathology in the central nervous system (CNS). Since there is no firm association between the amount of focal inflammatory lesions and disease severity, diffuse pathology in normal appearing white matter (NAWM) may be crucial for disease progression. Immunomodulating treatments for MS reduce the number of focal lesions, but possible effects on diffuse white matter pathology are less studied. Furthermore, it is not known whether intrathecal levels of inflammatory or neurodegenerative markers are associated with development of pathology in NAWM.

Methods

Quantitative proton magnetic resonance spectroscopy (¹H-MRS) was used to investigate NAWM in 27 patients with relapsing MS before and after one year of treatment with natalizumab as well as NAWM in 20 healthy controls at baseline. Changes in ¹H-MRS metabolite concentrations during treatment were also correlated with a panel of intrathecal markers of inflammation and neurodegeneration in 24 of these 27 patients.

Results

The group levels of ¹H-MRS metabolite concentrations were unchanged pre-to posttreatment, but a pattern of high magnitude correlation coefficients (r = 0.43–0.67, p<0.0005–0.03) were found between changes in individual metabolite concentrations (total creatine and total choline) and levels of pro-inflammatory markers (IL-1β and CXCL8).

Conclusions

Despite a clinical improvement and a global decrease in levels of inflammatory markers in cerebrospinal fluid during treatment, high levels of pro-inflammatory CXCL8 and IL-1β were associated with an increase in ¹H-MRS metabolites indicative of continued gliosis development and membrane turnover in NAWM.

Subacute neuronopathy in a young man: a possible association with tetracycline treatment

A young man with subacute neuronopathy following tetracycline treatment is described. The symptoms started as a sensory dorsal root affection but by time also involved motor nerves. He developed a severe sensory ataxia with pseudoathetotic movements. Other possible aetiologies were scrutinized and excluded. Tetracycline induced neuronopathy is hitherto not reported in the literature. We propose a possible association between treatment with tetracycline and the development of sensory neuronopathy in this patient.

Selective IgA deficiency in autoimmune diseases

Selective immunoglobulin A deficiency (IgAD) is the most common primary immunodeficiency in Caucasians. It has previously been suggested to be associated with a variety of concomitant autoimmune diseases. In this review, we present data on the prevalence of IgAD in patients with Graves disease (GD), systemic lupus erythematosus (SLE), type 1 diabetes (T1D), celiac disease (CD), myasthenia gravis (MG) and rheumatoid arthritis (RA) on the basis of both our own recent large-scale screening results and literature data. Genetic factors are important for the development of both IgAD and various autoimmune disorders, including GD, SLE, T1D, CD, MG and RA, and a strong association with the major histocompatibility complex (MHC) region has been reported. In addition, non-MHC genes, such as interferon-induced helicase 1 (IFIH1) and c-type lectin domain family 16, member A (CLEC16A), are also associated with the development of IgAD and some of the above diseases. This indicates a possible common genetic background. In this review, we present suggestive evidence for a shared genetic predisposition between these disorders.

A Swedish national post-marketing surveillance study of natalizumab treatment in multiple sclerosis

Background: A post marketing surveillance study was conducted to evaluate safety and efficacy of natalizumab in Swedish multiple sclerosis (MS) patients since its introduction in August 2006 until March 2010.

Methods: Patients were registered in the web-based Swedish MS-registry at 40 locations and evaluated every 6 months. Adverse events and clinical outcomes were recorded.

Results: One thousand one hundred and fifty-two patients were included (71.4% female) and 149 patients stopped treatment; the main reason was planned pregnancy. Anti-natalizumab antibodies were found in 4.5% (52 patients) of which 1.6% displayed persistent antibodies. Serious adverse events were rare, but included three cases with progressive multifocal leukoencephalopathy (PML). There were seven fatal cases, probably unrelated to the natalizumab treatment. For relapsing–remitting MS patients ( n = 901), mean Expanded Disability Status Scale (EDSS, −10.7%), Multiple Sclerosis Severity Scale (MSSS, −20.4%), Multiple Sclerosis Impact Scale (MSIS-29, physical −9.9%, psychological −13.3%) and Symbol Digit Modalities Test (SDMT, +10.7%) all showed significant improvements during 24 months of treatment with natalizumab. The Swedish web-based MS quality registry proved to function as a platform for post-marketing MS drug surveillance, providing long-term data regarding drug effects and adverse events beyond clinical trials.

Conclusions: Our results indicate that natalizumab is generally well tolerated and has sustained efficacy for patients with active MS, though the risk of PML is still an important concern.

Axonal damage in relapsing multiple sclerosis is markedly reduced by natalizumab

OBJECTIVE

The impact of present disease-modifying treatments (DMTs) in multiple sclerosis (MS) on nerve injury and reactive astrogliosis is still unclear. Therefore, we studied the effect of natalizumab treatment on the release of 2 brain-specific tissue damage markers into cerebrospinal fluid (CSF) in MS patients.

METHODS

CSF samples from 92 patients with relapsing forms of MS were collected in a prospective manner prior to natalizumab treatment and after 6 or 12 months. In 86 cases, natalizumab was used as second-line DMT due to breakthrough of disease activity. The levels of neurofilament light (NFL) and glial fibrillary acidic protein (GFAP) were determined using highly sensitive in-house developed enzyme-linked immunosorbent assays.

RESULTS

Natalizumab treatment led to a 3-fold reduction of NFL levels, from a mean value of 1,300 (standard deviation [SD], 2,200) to 400 (SD, 270) ng/l (p < 0.001). The later value was not significantly different from that found in healthy control subjects (350 ng/l; SD, 170; n = 28). Subgroup analysis revealed a consistent effect on NFL release, regardless of previous DMT or whether patients had relapses or were in remission within 3 months prior to natalizumab treatment. No differences between pre- and post-treatment levels of GFAP were detected.

INTERPRETATION

Our data demonstrate that natalizumab treatment reduces the accumulation of nerve injury in relapsing forms of MS. It is anticipated that highly effective anti-inflammatory treatment can reduce axonal loss, thereby preventing development of permanent neurological disability.