| 61. |
- Carlsson Almlöf, Jonas, et al.
(författare)
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Novel risk genes for systemic lupus erythematosus predicted by random forest classification
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies have identified risk loci for SLE, but a large proportion of the genetic contribution to SLE still remains unexplained. To detect novel risk genes, and to predict an individual's SLE risk we designed a random forest classifier using SNP genotype data generated on the "Immunochip" from 1,160 patients with SLE and 2,711 controls. Using gene importance scores defined by the random forest classifier, we identified 15 potential novel risk genes for SLE. Of them 12 are associated with other autoimmune diseases than SLE, whereas three genes (ZNF804A, CDK1, and MANF) have not previously been associated with autoimmunity. Random forest classification also allowed prediction of patients at risk for lupus nephritis with an area under the curve of 0.94. By allele-specific gene expression analysis we detected cis-regulatory SNPs that affect the expression levels of six of the top 40 genes designed by the random forest analysis, indicating a regulatory role for the identified risk variants. The 40 top genes from the prediction were overrepresented for differential expression in B and T cells according to RNA-sequencing of samples from five healthy donors, with more frequent over-expression in B cells compared to T cells.
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| 62. |
- Carlsson, Henrik, et al.
(författare)
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Measurement of hydroxychloroquine in blood from SLE patients using LC-HRMS : Evaluation of whole blood, plasma and serum as sample matrices
- 2020
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Ingår i: Arthritis Research & Therapy. - : BioMed Central. - 1478-6362. ; 22:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Hydroxychloroquine (HCQ) is the standard of care in the treatment of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and other inflammatory rheumatic diseases and potentially for the treatment in COVID-19 patients. Determination of HCQ for therapeutic drug monitoring (TDM) can be performed in whole blood (WB), serum, and plasma. Direct comparisons of WB, serum, and plasma levels of HCQ in patients with SLE have not previously been reported. We describe a method for the determination of HCQ in human blood using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and compare the suitability of the three sample matrices. Methods A method for the determination of HCQ in human blood using LC-HRMS was developed, validated, and applied for the determination of HCQ levels in WB, serum, and plasma from 26 SLE patients. The reproducibility of the method, in the three matrices, was evaluated using quality control samples and repeated preparations and measurements of patient samples. The performance of the developed method for HCQ measurement in serum was further evaluated by comparison with two previously reported extraction methods. Results The performance of the presented method demonstrated high accuracy and precision. A large range of HCQ concentrations was observed for the SLE patients in all three matrices (WB, serum, and plasma). The mean levels in WB were approximately two-fold the levels in serum and plasma (813 ng/mL compared to 436 ng/mL and 362 ng/mL, respectively). Spiked quality controls showed high reproducibility for all matrices (coefficient of variation, CV, approx. 5%), whereas in patient samples, equally high-precision was only found using WB as the matrix (CV 3%). The CV for serum and plasma was 14% and 39%, respectively. Two alternative methods applied to serum samples did not demonstrate improved precision. Conclusions A LC-HRMS method for the measurement of HCQ in human blood was developed and validated. Whole blood was found to be the superior sample matrix in terms of sample reproducibility. Thus, whole blood samples should be used for HCQ analysis when patients are monitored for HCQ treatment effects. The assay is in clinical use to monitor levels of HCQ in patients.
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| 63. |
- Cavalli, Marco, et al.
(författare)
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Allele-specific transcription factor binding to common and rare variants associated with disease and gene expression
- 2016
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Ingår i: Human Genetics. - : Springer Science and Business Media LLC. - 0340-6717 .- 1432-1203. ; 135:5, s. 485-497
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have identified a large number of disease-associated SNPs, but in few cases the functional variant and the gene it controls have been identified. To systematically identify candidate regulatory variants, we sequenced ENCODE cell lines and used public ChIP-seq data to look for transcription factors binding preferentially to one allele. We found 9962 candidate regulatory SNPs, of which 16 % were rare and showed evidence of larger functional effect than common ones. Functionally rare variants may explain divergent GWAS results between populations and are candidates for a partial explanation of the missing heritability. The majority of allele-specific variants (96 %) were specific to a cell type. Furthermore, by examining GWAS loci we found >400 allele-specific candidate SNPs, 141 of which were highly relevant in our cell types. Functionally validated SNPs support identification of an SNP in SYNGR1 which may expose to the risk of rheumatoid arthritis and primary biliary cirrhosis, as well as an SNP in the last intron of COG6 exposing to the risk of psoriasis. We propose that by repeating the ChIP-seq experiments of 20 selected transcription factors in three to ten people, the most common polymorphisms can be interrogated for allele-specific binding. Our strategy may help to remove the current bottleneck in functional annotation of the genome.
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| 64. |
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| 65. |
- Chemin, Karine, et al.
(författare)
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EOMES-positive CD4+ T cells are increased in PTPN22 (1858T) risk allele carriers.
- 2018
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Ingår i: European Journal of Immunology. - : Wiley. - 0014-2980 .- 1521-4141. ; 48:4, s. 655-669
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Tidskriftsartikel (refereegranskat)abstract
- The presence of the PTPN22 risk allele (1858T) is associated with several autoimmune diseases including rheumatoid arthritis (RA). Despite a number of studies exploring the function of PTPN22 in T cells, the exact impact of the PTPN22 risk allele on T-cell function in humans is still unclear. In this study, using RNA sequencing, we show that, upon TCR-activation, naïve human CD4+ T cells homozygous for the PTPN22 risk allele overexpress a set of genes including CFLAR and 4-1BB, which are important for cytotoxic T-cell differentiation. Moreover, the protein expression of the T-box transcription factor Eomesodermin (EOMES) was increased in T cells from healthy donors homozygous for the PTPN22 risk allele and correlated with a decreased number of naïve CD4+ T cells. There was no difference in the frequency of other CD4+ T cell subsets (Th1, Th17, Tfh, Treg). Finally, an accumulation of EOMES+CD4+ T cells was observed in synovial fluid of RA patients with a more pronounced production of Perforin-1 in PTPN22 risk allele carriers. Altogether, we propose a novel mechanism of action of PTPN22 risk allele through the generation of cytotoxic CD4+ T cells and identify EOMES+CD4+ T cells as a relevant T-cell subset in RA pathogenesis.
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| 66. |
- Crow, Mary K., et al.
(författare)
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Report of the inaugural Interferon Research Summit : interferon in inflammatory diseases
- 2018
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Ingår i: Lupus Science and Medicine. - : BMJ. - 2053-8790. ; 5:1
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Forskningsöversikt (refereegranskat)abstract
- An international summit on interferon (IFN) in inflammatory diseases, held in Gaithersburg, Maryland, USA (4-5 May 2017), united 22 internationally renowned clinicians and scientists with backgrounds in basic science, translational science and clinical medicine. The objectives of the summit were to assess the current knowledge of the role of type I IFN in inflammatory diseases and other conditions, discuss the available clinical trial data of anti-IFN therapeutic agents and identify key clinical and therapeutic knowledge gaps and future directions to advance the treatment landscape of diseases involving the type I IFN pathway. A discussion-based consensus process was used to assess three main clinical areas: the role of type I IFN in innate immunity, the role of type I IFN in autoimmune diseases and rational therapeutic targets in the IFN pathway. These are described here, along with current knowledge gaps and resulting recommendations. The advisors unanimously agreed that, despite significant obstacles, the field should transition from an organ-based model to a pathophysiology-based model. A better understanding of the molecular pathways could help inform potential therapeutic targets, thus progressing towards personalised medicine by tailoring the therapy to each patient.
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| 67. |
- Crow, Mary K., et al.
(författare)
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Type I interferons in host defence and inflammatory diseases
- 2019
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Ingår i: Lupus Science and Medicine. - : BMJ Publishing Group Ltd. - 2053-8790. ; 6:1
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Forskningsöversikt (refereegranskat)abstract
- Type I interferons (IFN) can have dual and opposing roles in immunity, with effects that are beneficial or detrimental to the individual depending on whether IFN pathway activation is transient or sustained. Determinants of IFN production and its functional consequences include the nature of the microbial or nucleic acid stimulus, the type of nucleic acid sensor involved in inducing IFN, the predominant subtype of type I IFN produced and the immune ecology of the tissue at the time of IFN expression. When dysregulated, the type I IFN system drives many autoimmune and non-autoimmune inflammatory diseases, including SLE and the tissue inflammation associated with chronic infection. The type I IFN system may also contribute to outcomes for patients affected by solid cancers or myocardial infarction. Significantly more research is needed to discern the mechanisms of induction and response to type I IFNs across these diseases, and patient endophenotyping may help determine whether the cytokine is acting as 'friend' or 'foe', within a particular patient, and at the time of treatment. This review summarises key concepts and discussions from the second International Summit on Interferons in Inflammatory Diseases, during which expert clinicians and scientists evaluated the evidence for the role of type I IFNs in autoimmune and other inflammatory diseases.
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| 68. |
- Cunninghame Graham, Deborah S, et al.
(författare)
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Association of NCF2, IKZF1, IRF8, IFIH1, and TYK2 with Systemic Lupus Erythematosus
- 2011
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Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 7:10, s. e1002341-
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Tidskriftsartikel (refereegranskat)abstract
- Systemic lupus erythematosus (SLE) is a complex trait characterised by the production of a range of auto-antibodies and a diverse set of clinical phenotypes. Currently, ∼8% of the genetic contribution to SLE in Europeans is known, following publication of several moderate-sized genome-wide (GW) association studies, which identified loci with a strong effect (OR>1.3). In order to identify additional genes contributing to SLE susceptibility, we conducted a replication study in a UK dataset (870 cases, 5,551 controls) of 23 variants that showed moderate-risk for lupus in previous studies. Association analysis in the UK dataset and subsequent meta-analysis with the published data identified five SLE susceptibility genes reaching genome-wide levels of significance (P(comb)<5×10(-8)): NCF2 (P(comb) = 2.87×10(-11)), IKZF1 (P(comb) = 2.33×10(-9)), IRF8 (P(comb) = 1.24×10(-8)), IFIH1 (P(comb) = 1.63×10(-8)), and TYK2 (P(comb) = 3.88×10(-8)). Each of the five new loci identified here can be mapped into interferon signalling pathways, which are known to play a key role in the pathogenesis of SLE. These results increase the number of established susceptibility genes for lupus to ∼30 and validate the importance of using large datasets to confirm associations of loci which moderately increase the risk for disease.
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| 69. |
- Dahlqvist, Johanna, 1979-, et al.
(författare)
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Identification and functional characterization of a novel susceptibility locus for small vessel vasculitis with MPO-ANCA
- 2022
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Ingår i: Rheumatology. - Oxford, United Kingdom : Oxford University Press (OUP). - 1462-0324 .- 1462-0332. ; 61:8, s. 3461-3470
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Tidskriftsartikel (refereegranskat)abstract
- Objective To identify and characterize genetic loci associated with the risk of developing ANCA-associated vasculitides (AAV). Methods Genetic association analyses were performed after Illumina sequencing of 1853 genes and subsequent replication with genotyping of selected single nucleotide polymorphisms in a total cohort of 1110 Scandinavian cases with granulomatosis with polyangiitis or microscopic polyangiitis, and 1589 controls. A novel AAV-associated single nucleotide polymorphism was analysed for allele-specific effects on gene expression using luciferase reporter assay. Results PR3-ANCA(+) AAV was significantly associated with two independent loci in the HLA-DPB1/HLA-DPA1 region [rs1042335, P = 6.3 x 10(-61), odds ratio (OR) 0.10; rs9277341, P = 1.5 x 10(-44), OR 0.22] and with rs28929474 in the SERPINA1 gene (P = 2.7 x 10(-10), OR 2.9). MPO-ANCA(+) AAV was significantly associated with the HLA-DQB1/HLA-DQA2 locus (rs9274619, P = 5.4 x 10(-25), OR 3.7) and with a rare variant in the BACH2 gene (rs78275221, P = 7.9 x 10(-7), OR 3.0), the latter a novel susceptibility locus for MPO-ANCA(+) granulomatosis with polyangiitis/microscopic polyangiitis. The rs78275221-A risk allele reduced luciferase gene expression in endothelial cells, specifically, as compared with the non-risk allele. Conclusion We identified a novel susceptibility locus for MPO-ANCA(+) AAV and propose that the associated variant is of mechanistic importance, exerting a regulatory function on gene expression in specific cell types.
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