| 1. |
- af Klint, Erik, et al.
(author)
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Evaluation of arthroscopy and macroscopic scoring.
- 2009
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In: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 11:3
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Arthroscopy is a minimally invasive technique for retrieving synovial biopsies in rheumatology during the past 20 years. Vital for its use is continual evaluation of its safety and efficacy. Important for sampling is the fact of intraarticular variation for synovial markers. For microscopic measurements scoring systems have been developed and validated, but for macroscopic evaluations there is a need for further comprehensive description and validation of equivalent scoring systems.METHODS: We studied the complication rate and yield of arthroscopies performed at our clinic between 1998 and 2005. We also created and evaluated a macroscopic score set of instructions for synovitis.RESULTS: Of 408 procedures, we had two major and one minor complication; two haemarthrosis and one wound infection, respectively. Pain was most often not a problem, but 12 procedures had to be prematurely ended due to pain. Yield of biopsies adequate for histology were 83% over all, 94% for knee joints and 34% for smaller joints. Video printer photographs of synovium taken during arthroscopy were jointly and individually reviewed by seven raters in several settings, and intra and inter rater variation was calculated. A macroscopic synovial scoring system for arthroscopy was created (Macro-score), based upon hypertrophy, vascularity and global synovitis. These written instructions were evaluated by five control-raters, and when evaluated individual parameters were without greater intra or inter rater variability, indicating that the score is reliable and easy to use.CONCLUSIONS: In our hands rheumatologic arthroscopy is a safe method with very few complications. For knee joints it is a reliable method to retrieve representative tissue in clinical longitudinal studies. We also created an easy to use macroscopic score, that needs to be validated against other methodologies. We hope it will be of value in further developing international standards in this area.
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| 2. |
- Carlberg, Konstantin, et al.
(author)
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Integrated Single Cell and Spatial Transcriptomics Reveal Autoreactive Differentiated B Cells in Joints of Early Rheumatoid Arthritis
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Other publication (other academic/artistic)abstract
- Rheumatoid Arthritis (RA) is a prevalent autoimmune disease characterized by inflammation of peripheral joints. Patients can be subdivided by the presence or absence of Rheumatoid Factor and anti-citrullinated protein antibodies (ACPA) in their circulation. Inflammation of the joint tissue is associated with infiltration of leukocytes from the blood, which can result in generation of lymphoid structures composed of B and T cells. Previous studies have shown that both memory B cells and antibody-secreting plasma cells populate the rheumatic joint tissue when captured from established and often long-standing disease. However, it has remained unclear, whether these cells are autoreactive and whether the associated lymphoid structures are present at the site of inflammation already at the time of diagnosis. Here, we used an integrated single cell and spatial transcriptomic approach to study B and plasma cells in synovial tissue of ACPA- and ACPA+ RA patients at this early time point. We found evidence for T cell help to B cells and presence of memory B and plasma cell pools in ACPA- as well as in ACPA+ RA. Our results demonstrated common supportive microenvironments in both patient subgroups, clonal relationships between the memory B and plasma cell pools and autoreactivity within the plasma cell compartment. These findings challenge our understanding of the dynamics of local adaptive immune responses in the RA joint of ACPA- and ACPA+ patients at the time of diagnosis, with direct implications for B and T cell targeting therapies for both patient subgroups.
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| 3. |
- Hardt, Uta, et al.
(author)
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Integrated single cell and spatial transcriptomics reveal autoreactive differentiated B cells in joints of early rheumatoid arthritis
- 2022
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- B cells play a significant role in established Rheumatoid Arthritis (RA). However, it is unclear to what extent differentiated B cells are present in joint tissue already at the onset of disease. Here, we studied synovial biopsies (n = 8) captured from untreated patients at time of diagnosis. 3414 index-sorted B cells underwent RNA sequencing and paired tissue pieces were subjected to spatial transcriptomics (n = 4). We performed extensive bioinformatics analyses to dissect the local B cell composition. Select plasma cell immunoglobulin sequences were expressed as monoclonal antibodies and tested by ELISA. Memory and plasma cells were found irrespective of autoantibody status of the patients. Double negative memory B cells were prominent, but did not display a distinct transcriptional profile. The tissue architecture implicate both local B cell maturation via T cell help and plasma cell survival niches with a strong CXCL12-CXCR4 axis. The immunoglobulin sequence analyses revealed clonality between the memory B and plasma cell pools further supporting local maturation. One of the plasma cell-derived antibodies displayed citrulline autoreactivity, demonstrating local autoreactive plasma cell differentiation in joint biopsies captured from untreated early RA. Hence, plasma cell niches are not a consequence of chronic inflammation, but are already present at the time of diagnosis.
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| 4. |
- Klint, Erik af
(author)
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Studies of the synovial membrane in chronic rheumatic joint disease
- 2006
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Doctoral thesis (other academic/artistic)abstract
- Background: The synovial membrane (SM) outlines the inner cavity of synovial joints except for cartilage surfaces. The SM is the target organ of immune-mediated responses in chronic arthritis, including rheumatoid arthritis (RA). RA is a common joint disease (prevalence of 0.5-1.0%) which is characterized by recurrent joint inflammation, with increasing joint damage and disability. The study of the SM in vivo provides important information about disease pathogenesis and response to treatment. The aim of this thesis was to study a method for biopsy retrieval, arthroscopy, SM variation by gene and protein expression and SM response to anti-rheumatic therapy. Results: In these studies we have added to existing evidence that arthroscopy is a safe and reliable method for synovial tissue retrieval. We have constructed and validated an easy to use macroscopic score for arthroscopy. This score needs validation against other methodologies. We have studied variability of synovial gene expression, where we could see that samples close to one another were more related than samples further apart, especially from other patients. Arthroscopic biopsies had less intrinsic variation than had orthopaedic material. We have shown that injection of intra articular glucocorticosteroids (GCs) reduces protein expression of synovial proinflammatory molecules (TNF, IL-1β, extra-nuclear HMGB-1, ICAM-1 and VEGF) and T cells. mRNA expression was reduced for IL-1α and IL-1β, but not for TNF or HMGB-1. Unexpectedly, no changes were evident in macrophage infiltration and the vascular compartment. Vascular proinflammatory cytokine expression persisted. We have shown that mPGES-1 (an enzyme in the prostaglandin E2 synthesis pathway) is strongly expressed in RA lining cells, and also in sublining macrophages, synovial fibroblasts and endothelial cells. We also saw that mPGES-1 and COX-2 co-localised in cells from synovial fluid and tissue. Finally mPGES-1 and COX-2 were down-regulated by local GC treatment, but not by systemic TNF antagonists. We have shown that markers of destruction were positively affected by both GCs and TNF antagonists, although differently. RANKL was down-regulated by GCs and OPG was up-regulated by TNF-blockade, leading to a favourable reduction of RANKL/OPG ratio by both treatments. We have provided evidence that TNF-antagonists induce apoptosis in RA SM macrophages, but not lymphocytes. Conclusion: Arthroscopy is a well tolerated, safe and reliable tool that will continue to be important for synovial tissue sampling. Synovial variation has to be considered when sampling the SM. By local GC treatment signs of inflammation persist, perhaps contributing to later disease relapse. We provided evidence for two inducible enzymes in the prostaglandin synthesis pathway, and showed that inhibition depended on therapy. mPGES-1 inhibitors would be an interesting future therapy possibly without the adverse effects of the cyclooxygenase inhibitors. Interestingly both GC and anti-TNF therapy reduced the RANKL/OPG ratio, an indirect sign of reduced osteoclast activity, although by different path ways. These findings provide support for a biological background for the slowing of joint destructions by these treatments. The increase in apoptosis of macrophages indicate that TNF antagonists make the local environment more normal, as reduced apoptosis is a classical feature in active RA SM. Two important questions remain: Is it possible to predict treatment response, and thereby minimise patient suffering? Is it possible to understand disease pathogenesis, and develop a cure? These are questions that need answering, and using SM as a source for research will possibly provide with important leads. Studying old and especially the new targeted therapies represent important opportunities to these questions.
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| 5. |
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| 6. |
- Lindberg, Johan, 1977-, et al.
(author)
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Effect of infliximab on mRNA expression profiles in synovial tissue of rheumatoid arthritis patients
- 2006
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In: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 8:6, s. R179-
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Journal article (peer-reviewed)abstract
- We examined the gene expression profiles in arthroscopic biopsies retrieved from 10 rheumatoid arthritis patients before and after anti-TNF treatment with infliximab to investigate whether such profiles can be used to predict responses to the therapy, and to study effects of the therapy on the profiles. Responses to treatment were assessed using European League Against Rheumatism response criteria. Three patients were found to be good responders, five patients to be moderate responders and two patients to be nonresponders. The TNF-alpha status of the biopsies from each of the patients before treatment was also investigated immunohistochemically, and it was detected in biopsies from four of the patients, including all three of the good responders. The gene expression data demonstrate that all patients had unique gene expression signatures, with low intrapatient variability between biopsies. The data also revealed significant differences between the good responding and nonresponding patients (279 differentially expressed genes were detected, with a false discovery rate < 0.025). Among the identified genes we found that MMP-3 was significantly upregulated in good responders (log(2) fold change, 2.95) compared with nonresponders, providing further support for the potential of MMP-3 as a marker for good responses to therapy. An even more extensive list of 685 significantly differentially expressed genes was found between patients in whom TNF-alpha was found and nonresponders, indicating that TNF-alpha could be an important biomarker for successful infliximab treatment. Significant differences were also observed between biopsies taken before and after anti-TNF treatment, including 115 differentially expressed genes in the good responding group. Interestingly, the effect was even stronger in the group in which TNF-a was immunohistochemically detected before therapy. Here, 1,058 genes were differentially expressed, including many that were novel in this context (for example, CXCL3 and CXCL14). Subsequent Gene Ontology analysis revealed that several 'themes' were significantly over-represented that are known to be affected by anti-TNF treatment in inflammatory tissue; for example, immune response (GO:0006955), cell communication (GO:0007154), signal transduction (GO:0007165) and chemotaxis (GO:0006935). No genes reached statistical significance in the moderately responding or nonresponding groups. In conclusion, this pilot study suggests that further investigation is warranted on the usefulness of gene expression profiling of synovial tissue to predict and monitor the outcome of rheumatoid arthritis therapies.
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| 7. |
- Lindberg, Johan, 1977-, et al.
(author)
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Variability in synovial inflammation in rheumatoid arthritis investigated by microarray technology
- 2006
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In: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 8:2
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Journal article (peer-reviewed)abstract
- In recent years microarray technology has been used increasingly to acquire knowledge about the pathogenic processes involved in rheumatoid arthritis. The present study investigated variations in gene expression in synovial tissues within and between patients with rheumatoid arthritis. This was done by applying microarray technology on multiple synovial biopsies obtained from the same knee joints. In this way the relative levels of intra-patient and inter-patient variation could be assessed. The biopsies were obtained from 13 different patients: 7 by orthopedic surgery and 6 by rheumatic arthroscopy. The data show that levels of heterogeneity varied substantially between the biopsies, because the number of genes found to be differentially expressed between pairs of biopsies from the same knee ranged from 6 to 2,133. Both arthroscopic and orthopedic biopsies were examined, allowing us to compare the two sampling methods. We found that the average number of differentially expressed genes between biopsies from the same patient was about three times larger in orthopedic than in arthroscopic biopsies. Using a parallel analysis of the tissues by immunohistochemistry, we also identified orthopedic biopsies that were unsuitable for gene expression analysis of synovial inflammation due to sampling of non-inflamed parts of the tissue. Removing these biopsies reduced the average number of differentially expressed genes between the orthopedic biopsies from 455 to 171, in comparison with 143 for the arthroscopic biopsies. Hierarchical clustering analysis showed that the remaining orthopedic and arthroscopic biopsies had gene expression signatures that were unique for each patient, apparently reflecting patient variation rather than tissue heterogeneity. Subsets of genes found to vary between biopsies were investigated for overrepresentation of biological processes by using gene ontology. This revealed representative 'themes' likely to vary between synovial biopsies affected by inflammatory disease.
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