| 1. |
- Nordmark, Gunnel, et al.
(author)
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Association of EBF1, FAM167A(C8orf13)-BLK and TNFSF4 gene variants with primary Sjögren's syndrome
- 2011
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In: Genes and Immunity. - : Springer Science and Business Media LLC. - 1466-4879 .- 1476-5470. ; 12:2, s. 100-109
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Journal article (peer-reviewed)abstract
- We performed a candidate gene association study in 540 patients with primary Sjögren's Syndrome (SS) from Sweden (n=344) and Norway (n=196) and 532 controls (n=319 Swedish, n=213 Norwegian). A total of 1139 single-nucleotide polymorphisms (SNPs) in 84 genes were analyzed. In the meta-analysis of the Swedish and Norwegian cohorts, we found high signals for association between primary SS and SNPs in three gene loci, not previously associated with primary SS. These are the early B-cell factor 1 (EBF1) gene, P=9.9 × 10−5, OR 1.68, the family with sequence similarity 167 member A–B-lymphoid tyrosine kinase (FAM167A–BLK) locus, P=4.7 × 10−4, OR 1.37 and the tumor necrosis factor superfamily (TNFSF4=Ox40L) gene, P=7.4 × 10−4, OR 1.34. We also confirmed the association between primary SS and the IRF5/TNPO3 locus and the STAT4 gene. We found no association between the SNPs in these five genes and the presence of anti-SSA/anti-SSB antibodies. EBF1, BLK and TNFSF4 are all involved in B-cell differentiation and activation, and we conclude that polymorphisms in several susceptibility genes in the immune system contribute to the pathogenesis of primary SS.
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| 2. |
- Enocsson, Helena, et al.
(author)
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Comparison of Surrogate Markers of the Type I Interferon Response and Their Ability to Mirror Disease Activity in Systemic Lupus Erythematosus
- 2021
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In: Frontiers in Immunology. - : Frontiers Media S.A.. - 1664-3224. ; 12
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Journal article (peer-reviewed)abstract
- Objectives: Type I interferons (IFNs) are central and reflective of disease activity in systemic lupus erythematosus (SLE). However, IFN-alpha levels are notoriously difficult to measure and the type I IFN gene signature (IGS) is not yet available in clinical routine. This study evaluates galectin-9 and an array of chemokines/cytokines in their potential as surrogate markers of type I IFN and/or SLE disease activity.Methods: Healthy controls and well-characterized Swedish SLE patients from two cross-sectional cohorts (n=181; n=59) were included, and a subgroup (n=21) was longitudinally followed. Chemokine/cytokine responses in immune complex triggered IFN-alpha activity was studied in healthy donor peripheral blood mononuclear cells (PBMC). Levels of chemokines/cytokines and galectin-9 were measured by immunoassays. Gene expression was quantified by qPCR.Results: The IGS was significantly (p<0.01) correlated with galectin-9 (rho=0.54) and CXCL10 (rho=0.37) levels whereas serum IFN-alpha correlated with galectin-9 (rho=0.36), CXCL10 (rho=0.39), CCL19 (rho=0.26) and CCL2 (rho=0.19). The strongest correlation was observed between galectin-9 and TNF (rho=0.56). IFN-alpha and disease activity (SLEDAI-2K) were correlated (rho=0.20) at cross-sectional analysis, but no significant associations were found between SLEDAI-2K and galectin-9 or chemokines. Several inflammatory mediators increased at disease exacerbation although CCL19, CXCL11, CXCL10, IL-10 and IL-1 receptor antagonist were most pronounced. Immune complex-stimulation of PBMC increased the production of CCL2, CXCL8 and TNF.Conclusion: Galectin-9 and CXCL10 were associated with type I IFN in SLE but correlated stronger with TNF. None of the investigated biomarkers showed a convincing association with disease activity, although CXCL10 and CCL19 performed best in this regard.
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| 3. |
- Eriksson, Per, et al.
(author)
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Successful Treatment of AA Amyloidosis in Ankylosing Spondylitis Using Tocilizumab: Report of Two Cases and Review of the Literature
- 2021
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In: Frontiers in Medicine. - : Frontiers Media SA. - 2296-858X. ; 8
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Research review (peer-reviewed)abstract
- Historically, secondary amyloidosis has been a feared complication of chronic inflammatory conditions. The fibril protein AA derives from the acute phase reactant serum amyloid A (SAA). Long-term elevation of SAA levels remains a major risk factor for the development of AA amyloidosis in rheumatic diseases, and the prognosis may be unpredictable. Nowadays, with increased availability of effective biological agents, the incidence of AA amyloidosis seems to be declining. Still, genetically predisposed subjects with slowly progressive disease and mild symptoms combined with ongoing systemic inflammation may be at risk. Interleukin-6 (IL-6) is one of the drivers of SAA release and effectiveness of the humanized anti-IL-6 receptor antibody tocilizumab (TCZ) for the treatment of AA amyloidosis has been observed in some rheumatic conditions. Herein, we report two male subjects with longstanding ankylosing spondylitis (AS) complicated by renal amyloidosis who received TCZ with rapid and beneficial effects regarding inflammation and proteinuria. To the best of our knowledge, the use of TCZ in AS patients with this extra-articular manifestation has not previously been described. The paper includes histopathology, clinical follow-up, and longitudinal data of the two cases along with a comprehensive review of relevant literature. Mechanisms behind amyloid-mediated tissue damage and organ dysfunction are discussed. Altogether, our data highlight that blocking IL-6 signaling may represent a promising therapeutic option in patients with renal AA amyloidosis.
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| 4. |
- Odqvist, Lina, et al.
(author)
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Genetic variations in A20 DUB domain provide a genetic link to citrullination and neutrophil extracellular traps in systemic lupus erythematosus
- 2019
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In: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 78:10, s. 1363-1370
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Journal article (peer-reviewed)abstract
- Objectives: Genetic variations in TNFAIP3 (A20) de-ubiquitinase (DUB) domain increase the risk of systemic lupus erythematosus (SLE) and rheumatoid arthritis. A20 is a negative regulator of NF-κB but the role of its DUB domain and related genetic variants remain unclear. We aimed to study the functional effects of A20 DUB-domain alterations in immune cells and understand its link to SLE pathogenesis. Methods: CRISPR/Cas9 was used to generate human U937 monocytes with A20 DUB-inactivating C103A knock-in (KI) mutation. Whole genome RNA-sequencing was used to identify differentially expressed genes between WT and C103A KI cells. Functional studies were performed in A20 C103A U937 cells and in immune cells from A20 C103A mice and genotyped healthy individuals with A20 DUB polymorphism rs2230926. Neutrophil extracellular trap (NET) formation was addressed ex vivo in neutrophils from A20 C103A mice and SLE-patients with rs2230926. Results: Genetic disruption of A20 DUB domain in human and murine myeloid cells did not give rise to enhanced NF-κB signalling. Instead, cells with C103A mutation or rs2230926 polymorphism presented an upregulated expression of PADI4, an enzyme regulating protein citrullination and NET formation, two key mechanisms in autoimmune pathology. A20 C103A cells exhibited enhanced protein citrullination and extracellular trap formation, which could be suppressed by selective PAD4 inhibition. Moreover, SLE-patients with rs2230926 showed increased NETs and increased frequency of autoantibodies to citrullinated epitopes. Conclusions: We propose that genetic alterations disrupting the A20 DUB domain mediate increased susceptibility to SLE through the upregulation of PADI4 with resultant protein citrullination and extracellular trap formation.
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| 5. |
- Svanberg, Cecilia, et al.
(author)
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Conformational state of C-reactive protein is critical for reducing immune complex-triggered type I interferon response: Implications for pathogenic mechanisms in autoimmune diseases imprinted by type I interferon gene dysregulation
- 2023
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In: Journal of Autoimmunity. - : ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD. - 0896-8411 .- 1095-9157. ; 135
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Journal article (peer-reviewed)abstract
- Presence of autoantibodies targeting nuclear constituents, i.e., double-stranded DNA and small nuclear ribonu-cleoproteins (snRNPs), remain a cornerstone in systemic lupus erythematosus (SLE). Fc gamma receptor IIa (Fc gamma RIIa) dependent uptake of nucleic acid containing immune complexes (ICs) by plasmacytoid dendritic cells (PDCs) can activate toll-like receptors (TLRs) such as TLR7 and TLR9 resulting in type I interferon (IFN) production. Pre-viously, the classical liver-derived acute-phase reactant C-reactive protein (CRP) has been suggested to reduce IC -induced type I IFN production, whereas monomeric (mCRP) vs. pentameric (pCRP) mediated effects have not yet been unraveled. Herein, peripheral blood mononuclear cells (PBMCs) or enriched blood DCs from healthy vol-unteers were stimulated with SLE sera, snRNP-IgG (ICs), or TLR ligands with or without pCRP, mCRP, or anti- Fc gamma RIIa antibody. Type I IFNs and cytokine responses were investigated using quantitative PCR, ELISA, and flow cytometry. pCRP inhibited IFN gene expression in PBMCs and enriched DCs after incubation with ICs, compared to ICs alone, whereas mCRP had significantly less inhibitory effect. The effect was independent on the order in which IC or CRP was added to the cells. In addition, pCRP inhibited IFN induced by other TLR stimulators, implicating broader inhibitory effects induced by pCRP. We demonstrate pronounced immunoregulatory functions of CRP whereas the inhibitory properties were evidently dependent on CRPs intact conformational state. The inhibition of type I IFNs was not due to competition of Fc gamma Rs, or binding of CRP to the ICs. Our findings have implications for autoimmune IC-mediated conditions imprinted by type I IFN gene dysregulation.
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| 6. |
- Urbonaviciute, Vilma, et al.
(author)
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Low Production of Reactive Oxygen Species Drives Systemic Lupus Erythematosus
- 2019
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In: Trends in Molecular Medicine. - : Elsevier BV. - 1471-4914 .- 1471-499X.
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Journal article (other academic/artistic)abstract
- Systemic lupus erythematosus (SLE) is a common autoimmune disease. Recent findings have shown that a major single nucleotide variant predisposing to SLE is associated with low production of reactive oxygen species (ROS). A variant amino acid in a frequent NCF1 allele causing deficient ROS production leads to an exaggerated type I interferon (IFN) response, earlier disease onset, and higher susceptibility to SLE. It is the so far strongest identified single nucleotide variant, with an odds ratio (OR) of >3 and an allele frequency of >10%. Its functional role is in sharp contrast to the earlier belief that excessive ROS production is exclusively pathogenic rather than protective. It opens new possibilities to understand the pathogenesis of SLE and to develop novel diagnostics and treatment strategies.
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| 7. |
- Viljanen, Johan V., et al.
(author)
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Synthesis of an Array of Triple-Helical Peptides from Type II Collagen for Multiplex Analysis of Autoantibodies in Rheumatoid Arthritis
- 2020
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In: ACS Chemical Biology. - : American Chemical Society (ACS). - 1554-8929 .- 1554-8937. ; 15:9
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Journal article (peer-reviewed)abstract
- Type II collagen (CII) is the most abundant protein in joint cartilage. Antibodies to CII appear around the clinical onset of the autoimmune disease rheumatoid arthritis (RA) in a subset of patients. They target specific epitopes on CII and can be pathogenic or protective. Assays for early detection of such autoantibodies may provide new opportunities for selecting effective treatment strategies of RA. We report the efficient and reproducible assembly of an array of covalently branched native and citrullinated triple helical peptides (THPs) from CII that contain defined autoantibody epitopes. Both monoclonal antibodies and sera from experimental mouse models show a unique reactivity toward the THPs, compared to cyclic peptides containing the epitopes, revealing the importance that the epitopes are displayed in a triple-helical conformation. Importantly, antibodies against three of the THPs that contain major CII epitopes were found to be increased in sera from patients with RA, compared to control persons. These results indicate that such synthetic THPs should be included in multiplex analysis of autoantibodies that are uniquely occurring in individuals with early RA, to provide valuable information on disease prognosis and on what type of therapy should be chosen for individual patients. Copyright © 2020 American Chemical Society.
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| 8. |
- Wirestam, Lina, et al.
(author)
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Interferon-α coincides with suppressed levels of pentraxin-3 (PTX3) in systemic lupus erythematosus and regulates leucocyte PTX3 in vitro
- 2017
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In: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 189:1, s. 83-91
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Journal article (peer-reviewed)abstract
- Dysfunctional elimination of cell debris, and the role of opsonins such as pentraxins, is of interest regarding systemic lupus erythematosus (SLE) pathogenesis. Interferon (IFN)- is typically elevated during SLE flares, and inhibits hepatocyte production of the pentraxin C-reactive protein' (CRP), partly explaining the poor correlation between CRP levels and SLE disease activity. The extrahepatically produced pentraxin 3' (PTX3) shares waste disposal functions with CRP, but has not been studied extensively in SLE. We analysed serum PTX3 in SLE, and assessed its interference with IFN- in vitro. Serum samples from 243 patients with SLE and 100 blood donors were analysed regarding PTX3. Patient sera were analysed for IFN-, and genotyped for three PTX3 single nucleotide polymorphisms reported previously to associate with PTX3 levels. Stimulated PTX3 release was assessed in the presence or absence of IFN- in blood donor neutrophils and peripheral blood mononuclear cells (PBMC). Serum PTX3 was 44% lower in patients with SLE compared to blood donors (P<00001) and correlated with leucocyte variables. Patients with undetectable IFN- had 29% higher median PTX3 level than patients with detectable IFN- (P=001). PTX3 production by PBMC was inhibited by IFN-, whereas neutrophil degranulation of PTX3 was increased. No differences in PTX3 levels were observed between the SNPs. In conclusion, median serum PTX3 is lower in SLE (especially when IFN- is detectable) compared to blood donors. In addition to its potential consumption during waste disposal, it is plausible that IFN- also attenuates PTX3 by inhibiting synthesis by PBMC and/or exhausting PTX3 storage in neutrophil granules.
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| 9. |
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