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- Lundtoft, Christian, et al.
(författare)
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Strong Association of Combined Genetic Deficiencies in the Classical Complement Pathway With Risk of Systemic Lupus Erythematosus and Primary Sjogren's Syndrome
- 2022
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Ingår i: Arthritis & Rheumatology. - : Wiley. - 2326-5191 .- 2326-5205. ; 74:11, s. 1842-1850
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Tidskriftsartikel (refereegranskat)abstract
- Objective Complete genetic deficiency of the complement component C2 is a strong risk factor for monogenic systemic lupus erythematosus (SLE), but whether heterozygous C2 deficiency adds to the risk of SLE or primary Sjogren's syndrome (SS) has not been studied systematically. This study was undertaken to investigate potential associations of heterozygous C2 deficiency and C4 copy number variation with clinical manifestations in patients with SLE and patients with primary SS. Methods The presence of the common 28-bp C2 deletion rs9332736 and C4 copy number variation was examined in Scandinavian patients who had received a diagnosis of SLE (n = 958) or primary SS (n = 911) and in 2,262 healthy controls through the use of DNA sequencing. The concentration of complement proteins in plasma and classical complement function were analyzed in a subgroup of SLE patients. Results Heterozygous C2 deficiency-when present in combination with a low C4A copy number-substantially increased the risk of SLE (odds ratio [OR] 10.2 [95% confidence interval (95% CI) 3.5-37.0]) and the risk of primary SS (OR 13.0 [95% CI 4.5-48.4]) when compared to individuals with 2 C4A copies and normal C2. For patients heterozygous for rs9332736 with 1 C4A copy, the median age at diagnosis was 7 years earlier in patients with SLE and 12 years earlier in patients with primary SS when compared to patients with normal C2. Reduced C2 levels in plasma (P = 2 x 10(-9)) and impaired function of the classical complement pathway (P = 0.03) were detected in SLE patients with heterozygous C2 deficiency. Finally, in a primary SS patient homozygous for C2 deficiency, we observed low levels of anti-Scl-70, which suggests a risk of developing systemic sclerosis or potential overlap between primary SS and other systemic autoimmune diseases. Conclusion We demonstrate that a genetic pattern involving partial deficiencies of C2 and C4A in the classical complement pathway is a strong risk factor for SLE and for primary SS. Our results emphasize the central role of the complement system in the pathogenesis of both SLE and primary SS.
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| 2. |
- Hober, Sophia, Professor, 1965-, et al.
(författare)
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Systematic evaluation of SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay
- 2021
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Ingår i: Clinical & Translational Immunology. - : Wiley. - 2050-0068. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Objective. The COVID-19 pandemic poses an immense need for accurate, sensitive and high-throughput clinical tests, and serological assays are needed for both overarching epidemiological studies and evaluating vaccines. Here, we present the development and validation of a high-throughput multiplex bead-based serological assay. Methods. More than 100 representations of SARS-CoV-2 proteins were included for initial evaluation, including antigens produced in bacterial and mammalian hosts as well as synthetic peptides. The five best-performing antigens, three representing the spike glycoprotein and two representing the nucleocapsid protein, were further evaluated for detection of IgG antibodies in samples from 331 COVID-19 patients and convalescents, and in 2090 negative controls sampled before 2020. Results. Three antigens were finally selected, represented by a soluble trimeric form and the S1-domain of the spike glycoprotein as well as by the C-terminal domain of the nucleocapsid. The sensitivity for these three antigens individually was found to be 99.7%, 99.1% and 99.7%, and the specificity was found to be 98.1%, 98.7% and 95.7%. The best assay performance was although achieved when utilising two antigens in combination, enabling a sensitivity of up to 99.7% combined with a specificity of 100%. Requiring any two of the three antigens resulted in a sensitivity of 99.7% and a specificity of 99.4%. Conclusion. These observations demonstrate that a serological test based on a combination of several SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay.
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| 3. |
- Lundtoft, Christian, et al.
(författare)
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Complement C4 copy number variation is linked to SSA/Ro and SSB/La autoantibodies in systemic inflammatory autoimmune diseases.
- 2022
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Ingår i: Arthritis & rheumatology (Hoboken, N.J.). - : Wiley. - 2326-5205 .- 2326-5191. ; 74:8, s. 1440-1450
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Tidskriftsartikel (refereegranskat)abstract
- Copy number variation of the C4 complement components, C4A and C4B, has been associated with systemic inflammatory autoimmune diseases. We asked if C4 copy number variation is connected to the autoimmune repertoire in systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS) or myositis.Using targeted DNA sequencing, we determined the copy number and genetic variants of C4 in 2,290 well-characterised Scandinavian patients with SLE, pSS or myositis, and 1,251 healthy controls.A prominent relationship was observed between C4A copy number and the presence of SSA/SSB autoantibodies, which was shared between the three diseases. The strongest association was detected for patients with autoantibodies against both SSA and SSB and 0 C4A copies when compared to healthy controls (OR=18.0; CI95% : 10.2-33.3), whereas a weaker association was seen for patients without SSA/SSB autoantibodies (OR=3.1; CI95% : 1.7-5.5). The copy number of C4 correlated positively with C4 plasma levels. Further, a common loss-of-function variant in C4A leading to reduced plasma C4 was more prevalent in SLE patients with a low copy number of C4A. Functionally, we showed that absence of C4A reduced the individuals' capacity to deposit C4b on immune complexes.We show that a low C4A copy number more strongly is associated with the autoantibody repertoire than with the clinically defined disease entities. These results may have implication for understanding the aetiopathogenetic mechanisms of systemic inflammatory autoimmune diseases, and for patient stratification when taking the genetic profile into account. This article is protected by copyright. All rights reserved.
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| 4. |
- Svenungsson, E., et al.
(författare)
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Quick Systemic Lupus Activity Questionnaire (Q-SLAQ): a simplified version of SLAQ for patient-reported disease activity
- 2021
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Ingår i: Lupus Science & Medicine. - : BMJ. - 2053-8790. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Objectives Most indices of disease activity in SLE combine physicians' assessments and laboratory tests. However, there is also a need to capture patients' perspectives of disease activity. Consequently, we need new, preferably quick and easy instruments to collect this information, which can be very useful for online consultations and registry purposes. We compared patients' assessments of SLE disease impact/activity, as reported by a shorter version of the Quick Systemic Lupus Activity Questionnaire (Q-SLAQ), with physicians' assessments using SLE Activity Measure (SLAM) and SLE Disease Activity Index (SLEDAI-2K) and with the original Systemic Lupus Activity Questionnaire (SLAQ). Methods Patients with SLE (n=115), with a disease duration of 15 years (IQR 17), completed the Q-SLAQ prior to physicians' assessments by SLAM and SLEDAI-2K. A second set of patients (n=85) with similar characteristics filled out Q-SLAQ and SLAQ. Spearman's rho correlations were explored between patients' total Q-SLAQ and subscales (Symptom Score, Patient's Global Disease Activity) and physicians' SLAM and SLEDAI-2K, with and without laboratory items (SLAM-nolab and SLEDAI-2K-nolab) and SLAQ. Corresponding items in Q-SLAQ and SLAM were compared. Results Correlations between patients' and physicians' assessments were higher for SLAM-nolab (total Q-SLAQ, rho=0.71; Symptom Score, rho=0.67; and Patient's Global Disease Activity, rho=0.68) than for the original SLAM (total Q-SLAQ, rho=0.53; Symptom Score, rho=0.50; and Patient's Global Disease Activity, rho=0.53). Regarding specific symptoms, fatigue (rho=0.72) and alopecia (rho=0.71) correlated best, while pulmonary/respiratory symptoms correlated least (rho=0.19, p=0.039). Physicians assessment with SLEDAI-2K-nolab correlated weakly with patients' assessments (total Q-SLAQ, rho=0.30; Symptom Score, rho=0.30; and Patient's Global Disease Activity, rho=0.36). Bivariate correlations between Q-SLAQ and SLAQ were good (rho=0.82-0.96). Conclusions Q-SLAQ and the original SLAQ performed equally well, demonstrating that the shorter Q-SLAQ can safely be used to monitor patients' perception of disease impact/activity. We also noted an intriguing discrepancy between physicians' and patients' evaluations of pulmonary/respiratory symptoms, which requires further investigations.
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| 5. |
- Trysberg, Estelle, 1960, et al.
(författare)
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Decreased levels of soluble amyloid beta-protein precursor and beta-amyloid protein in cerebrospinal fluid of patients with systemic lupus erythematosus
- 2004
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Ingår i: Arthritis Res Ther. - : Springer Science and Business Media LLC. - 1478-6362 .- 1465-9905. ; 6:2
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Tidskriftsartikel (refereegranskat)abstract
- Symptoms originating from the central nervous system (CNS) frequently occur in patients with systemic lupus erythematosus (SLE). These symptoms are extremely diverse, including a state of dementia. The aim of this study was to examine the cerebrospinal fluid (CSF) content of soluble molecules indicating axonal degeneration and amyloidogenesis.One hundred and fourteen patients with SLE and age-matched controls were evaluated clinically, with magnetic resonance imaging of the brain and CSF analyses. Levels of tau, amyloid precursor protein (APP), beta-amyloid protein (Abeta42), and transforming growth factor beta (TGF-beta) were all determined using sandwich ELISAs.APP and Abeta42 levels were significantly decreased in SLE patients irrespective of their CNS involvement, as compared with healthy controls. Patients with neuropsychiatric SLE who underwent a second lumbar puncture following successful cyclophosphamide treatment showed further decreases of Abeta42. CSF-tau levels were significantly increased in SLE patients showing magnetic resonance imaging-verified brain pathology as compared with SLE patients without such engagement. Importantly, tau levels displayed significant correlation to Abeta42 levels in the CSF. Finally, TGF-beta levels were significantly increased in patients with neuropsychiatric SLE as compared with those without.Low intrathecal levels of Abeta42 found in SLE patients seem to be a direct consequence of a diminished production of APP, probably mediated by heavy anti-inflammatory/immuno-suppressive therapy. Furthermore, our findings suggest that CSF tau can be used as a biochemical marker for neuronal degeneration in SLE. Finally, the increased TGF-beta levels observed may support a notion of an ongoing anti-inflammatory response counteracting tissue injury caused by CNS lupus.
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