| 1. |
- Appelgren, Daniel, et al.
(author)
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Active NET formation in Libman–Sacks endocarditis without antiphospholipid antibodies : A dramatic onset of systemic lupus erythematosus
- 2018
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In: Autoimmunity. - : Informa UK Limited. - 0891-6934 .- 1607-842X. ; 51:6, s. 310-318
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Journal article (peer-reviewed)abstract
- Although neutrophil extracellular traps (NETs) have been highlighted in several systemic inflammatory diseases, their clinical correlates and potential pathological role remain obscure. Herein, we describe a dramatic onset of systemic lupus erythematosus (SLE) with clear-cut pathogenic implications for neutrophils and NET formation in a young woman with cardiac (Libman–Sacks endocarditis) and central nervous system (psychosis and seizures) involvement. Despite extensive search, circulating antiphospholipid autoantibodies, a hallmark of Libman–Sacks endocarditis, could not be detected. Instead, we observed active NET formation in the tissue of the mitral valve, as well as in the circulation. Levels of NET remnants were significantly higher in serially obtained sera from the patient compared with sex-matched blood donors (p =.0011), and showed a non-significant but substantial correlation with blood neutrophil counts (r = 0.65, p =.16). The specific neutrophil elastase activity measured in serum seemed to be modulated by the provided immunosuppressive treatment. In addition, we found anti-Ro60/SSA antibodies in the cerebrospinal fluid of the patient but not NET remnants or increased elastase activity. This case illustrates that different disease mechanisms mediated via autoantibodies can occur simultaneously in SLE. NET formation with release of cytotoxic NET remnants is a candidate player in the pathogenesis of this non-canonical form of Libman–Sacks endocarditis occurring in the absence of traditional antiphospholipid autoantibodies. The case description includes longitudinal results with clinical follow-up data and a discussion of the potential roles of NETs in SLE.
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| 2. |
- Diaz-Gallo, Lina-Marcela, et al.
(author)
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Four Systemic Lupus Erythematosus Subgroups, Defined by Autoantibodies Status, Differ Regarding HLA-DRB1 Genotype Associations and Immunological and Clinical Manifestations
- 2022
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In: ACR Open Rheumatology. - : John Wiley & Sons. - 2578-5745. ; 4:1, s. 27-39
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Journal article (peer-reviewed)abstract
- Objective: The heterogeneity of systemic lupus erythematosus (SLE) constitutes clinical and therapeutical challenges. We therefore studied whether unrecognized disease subgroups can be identified by using autoantibody profiling together with HLA-DRB1 alleles and immunological and clinical data.Methods: An unsupervised cluster analysis was performed based on detection of 13 SLE-associated autoantibodies (double-stranded DNA, nucleosomes, ribosomal P, ribonucleoprotein [RNP] 68, RNPA, Smith [Sm], Sm/RNP, Sjögren's syndrome antigen A [SSA]/Ro52, SSA/Ro60, Sjögren's syndrome antigen B [SSB]/La, cardiolipin [CL]-Immunoglobulin G [IgG], CL-Immunoglobulin M [IgM], and β2 glycoprotein I [β2 GPI]-IgG) in 911 patients with SLE from two cohorts. We evaluated whether each SLE subgroup is associated with HLA-DRB1 alleles, clinical manifestations (n = 743), and cytokine levels in circulation (n = 446).Results: Our analysis identified four subgroups among the patients with SLE. Subgroup 1 (29.3%) was dominated by anti-SSA/Ro60/Ro52/SSB autoantibodies and was strongly associated with HLA-DRB1*03 (odds ratio [OR] = 4.73; 95% confidence interval [CI] = 4.52-4.94). Discoid lesions were more common for this disease subgroup (OR = 1.71, 95% CI = 1.18-2.47). Subgroup 2 (28.7%) was dominated by anti-nucleosome/SmRNP/DNA/RNPA autoantibodies and associated with HLA-DRB1*15 (OR = 1.62, 95% CI = 1.41-1.84). Nephritis was most common in this subgroup (OR = 1.61, 95% CI = 1.14-2.26). Subgroup 3 (23.8%) was characterized by anti-ß2 GPI-IgG/anti-CL-IgG/IgM autoantibodies and a higher frequency of HLA-DRB1*04 compared with the other patients with SLE. Vascular events were more common in Subgroup 3 (OR = 1.74, 95% CI = 1.2-2.5). Subgroup 4 (18.2%) was negative for the investigated autoantibodies, and this subgroup was not associated with HLA-DRB1. Additionally, the levels of eight cytokines significantly differed among the disease subgroups.Conclusion: Our findings suggest that four fairly distinct subgroups can be identified on the basis of the autoantibody profile in SLE. These four SLE subgroups differ regarding associations with HLA-DRB1 alleles and immunological and clinical features, suggesting dissimilar disease pathways.
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| 3. |
- Langefeld, Carl D., et al.
(author)
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Transancestral mapping and genetic load in systemic lupus erythematosus
- 2017
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In: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 8
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Journal article (peer-reviewed)abstract
- Systemic lupus erythematosus (SLE) is an autoimmune disease with marked gender and ethnic disparities. We report a large transancestral association study of SLE using Immunochip genotype data from 27,574 individuals of European (EA), African (AA) and Hispanic Amerindian (HA) ancestry. We identify 58 distinct non-HLA regions in EA, 9 in AA and 16 in HA (similar to 50% of these regions have multiple independent associations); these include 24 novel SLE regions (P < 5 x 10(-8)), refined association signals in established regions, extended associations to additional ancestries, and a disentangled complex HLA multigenic effect. The risk allele count (genetic load) exhibits an accelerating pattern of SLE risk, leading us to posit a cumulative hit hypothesis for autoimmune disease. Comparing results across the three ancestries identifies both ancestry-dependent and ancestry-independent contributions to SLE risk. Our results are consistent with the unique and complex histories of the populations sampled, and collectively help clarify the genetic architecture and ethnic disparities in SLE.
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| 4. |
- Lundtoft, Christian, et al.
(author)
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Combined genetic deficiencies of the classical complement pathway are strongly associated with both systemic lupus erythematosus and primary Sjögren's syndrome
- 2022
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In: Arthritis & Rheumatology. - : Wiley. - 2326-5205 .- 2326-5191. ; 74:11, s. 1842-1850
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Journal article (peer-reviewed)abstract
- ObjectiveComplete 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 Sjögren's syndrome (pSS) has not been studied systematically. Here we investigated heterozygous C2 deficiency and C4 copy number variation in relation to clinical manifestations in SLE and pSS.MethodsThe presence of the common 28-bp C2 deletion rs9332736 and C4 copy number variation was examined in Scandinavian patients diagnosed with SLE (n=958) or pSS (n=911), and 2,262 controls using DNA sequencing. Plasma concentration of complement proteins and classical complement function was analysed in a subgroup of patients.ResultsHeterozygous C2 deficiency – when present in combination with a low C4A copy number – substantially increased the risk of SLE (OR=10.2, CI95%: 3.5-37.0) and pSS (OR=13.0, CI95%: 4.5-48.4) when compared to individuals with two C4A copies and normal C2. For patients heterozygous for rs9332736 with one C4A copy, the median age of diagnosis was 7 years and 12 years earlier in SLE and pSS, respectively. Reduced plasma C2 (p=2x10-9) and impaired function of the classical complement pathway (p=0.03) was detected in SLE patients with heterozygous C2 deficiency. Finally, we describe a pSS patient with homozygous C2 deficiency.ConclusionWe demonstrate that the combination of partial deficiencies of C2 and C4A in the classical complement pathway is a strong risk factor for SLE and pSS. Our results emphasise the central role of the complement system in the pathogenesis of both diseases.
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| 5. |
- Lundtoft, Christian, et al.
(author)
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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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In: Arthritis & rheumatology (Hoboken, N.J.). - : Wiley. - 2326-5205 .- 2326-5191. ; 74:8, s. 1440-1450
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Journal article (peer-reviewed)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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| 6. |
- Parodis, Ioannis, et al.
(author)
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Smoking and pre-existing organ damage reduce the efficacy of belimumab in systemic lupus erythematosus.
- 2017
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In: Autoimmunity Reviews. - : Elsevier BV. - 1568-9972 .- 1873-0183. ; 16:4, s. 343-351
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Journal article (peer-reviewed)abstract
- OBJECTIVES: Belimumab is the first biologic drug approved for Systemic Lupus Erythematosus (SLE). Here, we aimed to investigate the effects of belimumab on clinical and serologic outcomes, and sought to identify predictors of treatment response in three Swedish real-life settings.METHODS: Fifty-eight patients were enrolled at initiation of belimumab and followed longitudinally for up to 53months. Surveillance outcomes included the SLE Disease Activity Index 2000 (SLEDAI-2K), 100mm Visual Analogue Scales for Physician's Global Assessment (PGA), fatigue, pain and general health, and the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). Assessment of treatment response included the SLE responder index (SRI). B lymphocyte stimulator (BLyS) levels were determined using ELISA.RESULTS: SLEDAI-2K (median baseline score: 8.0; IQR: 4.0-13.8), PGA and corticosteroid use decreased during therapy, and patients reported improvements on fatigue, pain, and general health (p<0.0001 for all). SDI scores remained stable (p=0.08). Patients with baseline SDI scores >1 showed decreased probability and prolonged time to attain SRI response (HR: 0.449; 95% CI: 0.208-0.967), as did current smokers compared with non-smokers (HR: 0.103; 95% CI: 0.025-0.427). In contrast, baseline BLyS levels ≥1.2ng/mL predicted increased probability and shorter time to attain SRI response (HR: 2.566; 95% CI: 1.222-5.387).CONCLUSIONS: Disease activity and corticosteroid usage decreased, patient-reported outcomes improved, and no significant organ damage was accrued during follow-up. Smoking and organ damage predicted reduced treatment efficacy. These findings might contribute to a better selection of patients who are likely to benefit from belimumab.
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