1. |
- Asplund, Matthias, et al.
(author)
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Comparison of TOR lubrication systems on the iron ore line
- 2015
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Conference paper (peer-reviewed)abstract
- The Iron Ore Line (IOL) is a 473 km long track section which is located in northern Sweden and northern Norway, and has been in operation since 1903. The northern part is located above the Arctic Circle. The IOL is mainly used to transport iron ore and pellets from the mines in Kiruna and Malmberget to Narvik Harbour (Norway) in the northwest and Luleå Harbour (Sweden) in the southeast. The track section on the Swedish side is owned by the Swedish Government and managed by Trafikverket (the Swedish Transport Administration), while the ore wagons are owned and managed by the freight operator (LKAB).The IOL has seen a considerable increase in the axle load and traffic volume recently. Due to the introduction of new vehicles with a 30-ton axle load, the rails were gradually replaced between 2006 and 2009 with heavier rails, generally with a steel grade of 350LHT. The rail and wheels suffer from rolling contact fatigue (RCF) due to high friction between the rail and wheel. To control the wheel-rail interface, wayside top-of-rail (TOR) lubrication can be used. The reliability of the TOR lubrication equipment and the lubricants in northern conditions has not been investigated, and the long-term maintenance support required for TOR lubrication is unknown to the infrastructure manager. Furthermore, can TOR lubrication reduce the rail and wheel maintenance costs? This project has been conducted through collaboration between the main operator (LKAB) and the infrastructure manager (Trafikverket); the costs have been shared and the results analysed in collaboration. This paper describes the test period of two years, using two different TOR lubrication systems in two different places on the IOL, one situated in the northern loop and one in the southern loop, each with different operational conditions. The paper shows the actual operational conditions for the pilot test locations, the friction value close to the systems, the rail forces during the test period and some results for the noise measurements. Furthermore, the paper includes the improvements of system resulting from the test operation, and ends with recommendations for the continued use of TOR lubrication on the IOL.
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2. |
- Asplund, Matthias, et al.
(author)
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Improved wheel-rail system of Sweden’s iron ore line
- 2017
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In: Proceedings of the 11th International Heavy Haul Association Conference (IHHA 2017), Cape Town, South Africa, 2–6 September 2017. - 9780911382662 ; , s. 759-766
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Conference paper (other academic/artistic)abstract
- ABSTRACT: The Swedish Iron Ore Line (IOL) is the only heavy haul line in Europe. The northern part of the line is located above the Arctic Circle, a very harsh climate. Because of the introduction of new vehicles with a 30-tonnes axle load, the track were gradually replaced between 2006 and 2009 with heavier rails, mostly with a steel grade of R350LHT. Just after the first replacement of track in 2006, the project presented herein was established with the primary goal of improving the life length of the rail, and monitoring activities started. This project now has a unique database of rail degradation data. So far, the information has been used to improve the performance of the wheel-rail system and thus extend the life length of the rail, as well as to improve our knowledge of heavy haul operations in a cold climate. The paper discusses the project progress in general and gives some examples of improvements that have been successfully implemented, such as new rail profiles and a higher grinding frequency. Finally, it discusses the challenges of future capacity improvements, such as an increase in the axle load, and how these can be addressed.
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4. |
- Brito-Zeron, P., et al.
(author)
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How immunological profile drives clinical phenotype of primary Sjögren's syndrome at diagnosis : analysis of 10,500 patients (Sjögren Big Data Project)
- 2018
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In: Clinical and Experimental Rheumatology. - : CLINICAL & EXPER RHEUMATOLOGY. - 0392-856X .- 1593-098X. ; 36:3, s. S102-S112
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Journal article (peer-reviewed)abstract
- Objective: To evaluate the influence of the main immunological markers on the disease phenotype at diagnosis in a large international cohort of patients with primary Sjogren's syndrome (SjS).Methods: The Big Data Sjogren Project Consortium is an international, multicentre registry created in 2014. As a first step, baseline clinical information from leading centres on clinical research in SjS of the 5 continents was collected. The centres shared a harmonised data architecture and conducted cooperative online efforts in order to refine collected data under the coordination of a big data statistical team. Inclusion criteria were the fulfillment of the 2002 classification criteria. Immunological tests were carried out using standard commercial assays.Results: By January 2018, the participant centres had included 10,500 valid patients from 22 countries. The cohort included 9,806 (93%) women and 694 (7%) men, with a mean age at diagnosis of primary SjS of 53 years, mainly White (78%) and included from European countries (71%). The frequency of positive immunological markers at diagnosis was 79.3% for ANA, 73.2% for anti-Ro, 48.6% for RF, 45.1% for anti-La, 13.4% for low C3 levels, 14.5% for low C4 levels and 7.3% for cryoglobulins. Positive autoantibodies (ANA, Ro, La) correlated with a positive result in salivary gland biopsy, while hypocomplementaemia and especially cryoglobulinaemia correlated with systemic activity (mean ESSDAI score of 17.7 for ctyoglobulins, 11.3 for low C3 and 9.2 for low C4, in comparison with 3.8 for negative markers). The immunological markers with a great number of statistically-significant associations (p<0.001) in the organ-by-organ ESSDAI evaluation were cryoglobulins (9 domains), low C3 (8 domains), anti-La (7 domains) and low C4 (6 domains).Conclusion: We confirm the strong influence of immunological markers on the phenotype of primary SjS at diagnosis in the largest multi-ethnic international cohort ever analysed, with a greater influence for cryoglobulinaemic-related markers in comparison with Ro/La autoantibodies and ANA. Immunological patterns play a central role in the phenotypic expression of the disease already at the time of diagnosis, and may guide physicians to design a specific personalised management during the follow-up of patients with primary SjS.
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5. |
- Brito-Zerón, Pilar, et al.
(author)
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Influence of geolocation and ethnicity on the phenotypic expression of primary Sjögren's syndrome at diagnosis in 8310 patients : a cross-sectional study from the Big Data Sjögren Project Consortium
- 2017
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In: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 76:6, s. 1042-1050
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Journal article (peer-reviewed)abstract
- OBJECTIVES: To analyse the influence of geolocation and ethnicity on the clinical presentation of primary Sjögren's syndrome (SjS) at diagnosis.METHODS: The Big Data Sjögren Project Consortium is an international, multicentre registry designed in 2014. By January 2016, 20 centres from five continents were participating. Multivariable logistic regression analyses were performed.RESULTS: We included 7748 women (93%) and 562 men (7%), with a mean age at diagnosis of primary SjS of 53 years. Ethnicity data were available for 7884 patients (95%): 6174 patients (78%) were white, 1066 patients (14%) were Asian, 393 patients (5%) were Hispanic, 104 patients (1%) were black/African-American and 147 patients (2%) were of other ethnicities. SjS was diagnosed a mean of 7 years earlier in black/African-American compared with white patients; the female-to-male ratio was highest in Asian patients (27:1) and lowest in black/African-American patients (7:1); the prevalence of sicca symptoms was lowest in Asian patients; a higher frequency of positive salivary biopsy was found in Hispanic and white patients. A north-south gradient was found with respect to a lower frequency of ocular involvement in northern countries for dry eyes and abnormal ocular tests in Europe (OR 0.46 and 0.44, respectively) and Asia (OR 0.18 and 0.49, respectively) compared with southern countries. Higher frequencies of antinuclear antibodies (ANAs) were reported in northern countries in America (OR=1.48) and Asia (OR=3.80) while, in Europe, northern countries had lowest frequencies of ANAs (OR=0.67) and Ro/La (OR=0.69).CONCLUSIONS: This study provides the first evidence of a strong influence of geolocation and ethnicity on the phenotype of primary SjS at diagnosis.
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7. |
- Landegren, Nils, et al.
(author)
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Autoantibodies Targeting a Collecting Duct-Specific Water Channel in Tubulointerstitial Nephritis
- 2016
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In: Journal of the American Society of Nephrology: JASN. - 1533-3450 .- 1046-6673. ; 27:10, s. 3220-3228
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Journal article (peer-reviewed)abstract
- Tubulointerstitial nephritis is a common cause of kidney failure and may have diverse etiologies. This form of nephritis is sometimes associated with autoimmune disease, but the role of autoimmune mechanisms in disease development is not well understood. Here, we present the cases of three patients with autoimmune polyendocrine syndrome type 1 who developed tubulointerstitial nephritis and ESRD in association with autoantibodies against kidney collecting duct cells. One of the patients developed autoantibodies targeting the collecting duct-specific water channel aquaporin 2, whereas autoantibodies of the two other patients reacted against the HOXB7 or NFAT5 transcription factors, which regulate the aquaporin 2 promoter. Our findings suggest that tubulointerstitial nephritis developed in these patients as a result of an autoimmune insult on the kidney collecting duct cells.
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8. |
- Lin, Janet, et al.
(author)
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Data analysis of heavy haul wagon axle loads on Malmbanan line, Sweden : A case study for LKAB
- 2016
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Reports (other academic/artistic)abstract
- The research presented in this report was carried out by Operation and Maintenance Engineering at Luleå University of Technology (LTU) from November 2015 to April 2016. LKAB initiated the research study and provided financial support. The purpose of this research was to support LKAB and Trafikverket in their operational strategy review and optimization of future axle load implementations. It developed five research questions and answered them by analyzing the data for the Malmbanan iron ore train axle loads for 2015.Data analysis comprises four parts. In the first part (section 2), the analysis focuses on axle loads of all loaded trains operating at three different terminals: Kiruna, Malmberget, and Svappavaara. In addition, it examines the differences of three weighing locations in Kiruna, five weighing locations in Malmberget and four weighing locations in Svappavaara (12 weighing locations). Based on these results, the analysis in the second part (section 3) focuses on the heavy haul wagon. Wagon loads are evaluated and predicted for different loading rules (31.0 and 32.5 tons separately). To optimize the current loading rules, the third part of the analysis (section 4) proposes a novel approach to optimize the wagon axle loads: “three sigma prediction”. Under this approach, Kiruna, Malmberget and Svappavaara can set new target loads based on various risk levels. In the fourth and final part of the data analysis (section 5), a comparison study is carried out by collecting axle load data for the test train (with a 32.5 ton axle load) using three different measurement systems in Malmberget, Sävast and Sunderbyn. Finally, sections 6 and 7 summarize the results and make some recommendations for future work. The work presented in this report should give LKAB and Trafikverket a good overview of the load distribution for the ore trains operating on Malmbanan line. It can serve as input into the process of evaluating possible changes in axle load limits. It also gives LKAB a base from which to identify and work with optimization of the various loading places to load trains more efficiently and save costs.
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9. |
- Lin, Jing, et al.
(author)
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Data analysis of wheel-sets' running surface wear based on re-profiling measurement : a case study at Malmbanan
- 2015
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In: IHHA 2015 Conference proceedings. - : International Heavy Haul Association. - 9780646940069 ; , s. 924-930
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Conference paper (peer-reviewed)abstract
- In this paper, the wheel-sets’ running surface wear data based on re-profiling measurement from 16 bogies of heavy haul locomotives at Malmbanan (Sweden) are studied. The case study undertakes: reliability and degradation analysis, wear rate analysis and their comparison (including total wear rate, natural wear rate, re-profiling wear rate, the ratio of re-profiling and natural wear). The results show that: 1) for the studied group, a linear degradation path is more suitable; 2) following the linear degradation, the best life distribution is a 3-parameter Weibull distribution; 3) comparing the wearing data of the wheel-sets’ running surfaces is an effective way to optimize maintenance strategies; 4) more natural wear occurs for the wheels installed in axle 1 and axle 3, supportive evidence for other related studies at Malmbanan.
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10. |
- Mofors, J., et al.
(author)
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Concomitant Ro/SSA and La/SSB antibodies are biomarkers for the risk of venous thromboembolism and cerebral infarction in primary Sjögren's syndrome
- 2019
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In: Journal of Internal Medicine. - : John Wiley & Sons. - 0954-6820 .- 1365-2796. ; 286:4, s. 458-468
-
Journal article (peer-reviewed)abstract
- Background: To assess the risk of incident cardiovascular disease in patients with primary Sjögren's syndrome, overall and stratified by Ro/SSA and La/SSB autoantibody status.Methods: A cohort of patients with primary Sjögren's syndrome in Sweden (n = 960) and matched controls from the general population (n = 9035) were included, and data extracted from the National Patient Register to identify events of myocardial infarction, cerebral infarction and venous thromboembolism. Hazard ratios were estimated using cox proportional hazard regressions.Results: During a median follow‐up of 9.5 years, the overall hazard ratio (HR) was 1.6 (95% CI 1.2–2.1) for myocardial infarction, 1.2 (95% CI 0.9–1.7) for cerebral infarction and 2.1 (95% CI 1.6–2.9) for venous thromboembolism. Patients positive for both Ro/SSA and La/SSB autoantibodies had a substantially higher risk of cerebral infarction (HR 1.7, 95% CI 1.0–2.9) and venous thromboembolism (HR 3.1, 95% CI 1.9–4.8) than the general population. These risks were not significantly increased in Ro/SSA‐ and La/SSB‐negative patients. Among autoantibody‐positive patients, the highest HR of cerebral infarction was seen after ≥10 years disease duration (HR 2.8, 95% CI 1.4–5.4), while the HR for venous thromboembolism was highest 0–5 years after disease diagnosis (HR 4.7, 95% CI 2.3–9.3) and remained high throughout disease duration.Conclusions: Primary Sjögren's syndrome is associated with a markedly increased risk of cardiovascular disease and the presence of Ro/SSA and La/SSB autoantibodies identify the subgroup of patients carrying the highest risk. These findings suggest that monitoring and prevention of cardiovascular disease in this patient group should be considered.
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11. |
- Mofors, J., et al.
(author)
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Infections increase the risk of developing Sjögren's syndrome
- 2019
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In: Journal of Internal Medicine. - : Wiley-Blackwell. - 0954-6820 .- 1365-2796. ; 285:6, s. 670-680
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Journal article (peer-reviewed)abstract
- Objective: Environmental factors have been suggested in the pathogenesis of rheumatic diseases. We here investigated whether infections increase the risk of developing primary Sjögren's syndrome (pSS).Methods: Patients with pSS in Sweden (n = 945) and matched controls from the general population (n = 9048) were included, and data extracted from the National Patient Register to identify infections occurring before pSS diagnosis during a mean observational time of 16.0 years. Data were analysed using conditional logistic regression models. Sensitivity analyses were performed by varying exposure definition and adjusting for previous health care consumption.Results: A history of infection associated with an increased risk of pSS (OR 1.9, 95% CI 1.6–2.3). Infections were more prominently associated with the development of SSA/SSB autoantibody‐positive pSS (OR 2.7, 95% CI 2.0–3.5). When stratifying the analysis by organ system infected, respiratory infections increased the risk of developing pSS, both in patients with (OR 2.9, 95% CI 1.8–4.7) and without autoantibodies (OR 2.1, 95% CI 1.1–3.8), whilst skin and urogenital infections only significantly associated with the development of autoantibody‐positive pSS (OR 3.2, 95% CI 1.8–5.5 and OR 2.7, 95% CI 1.7–4.2). Furthermore, a dose–response relationship was observed for infections and a risk to develop pSS with Ro/SSA and La/SSB antibodies. Gastrointestinal infections were not significantly associated with a risk of pSS.Conclusions: Infections increase the risk of developing pSS, most prominently SSA/SSB autoantibody‐positive disease, suggesting that microbial triggers of immunity may partake in the pathogenetic process of pSS.
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15. |
- Nordmark, Thomas
(author)
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A Mining Companies Development of a Green Power Concept for Rebuilding Diesel Locomotives
- 2015
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In: 11th International Heavy Haul Conference, (IHHA 2015). - : International Heavy Haul Association. - 9780646940069 ; , s. 449-458
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Conference paper (peer-reviewed)abstract
- LKAB mining company needed to upgrade four T46 terminal locomotives because they had reached their technical life length and lacked the tractive effort to handle the new longer and heavier trains. The first idea was to buy new locomotives, but none suited LKAB’s specific requirements. The next idea was to turn to a locomotive rebuilding company. Unfortunately, the company closed down, forcing LKAB to do the rebuilding. This paper describes how the mining company turned locomotives built in 1973 into modern environmentally friendly, state-of-the art locomotives, tailor-made for the specific requirements and conditions of LKAB in operating iron ore transports in Kiruna Sweden. LKAB was the first company in Europe to meet the European emission regulation 3A/EPA (US Tier 2) by installing a diesel engine in a loco and therefor the name of the loco was T46 Green Power Concept (GPC). The most important result was the discovery that a mining company, or any other company, can rebuild a locomotive to meet the company’s specific requirements and tailor it to its operation, if it is important to do so, provided skilled people are available for this task. The money spent was equal to the cost of purchasing new locomotives, and delivery time was equal to having the rebuilding subcontracted out.
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16. |
- Nordmark, Thomas, et al.
(author)
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Use of electro-dynamic braking on locomotives and its effect on rolling contact fatigue
- 2017
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In: Proceedings of the 11th International Heavy Haul Association Conference (IHHA 2017), Cape Town, South Africa, 2–6 September 2017. - 9780911382662 ; , s. 1133-1137
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Conference paper (peer-reviewed)abstract
- ABSTRACT: The mining company LKAB uses IORE locomotives to haul iron ore trains. When evaluated using life cycle cost (LCC) analysis for reliability, availability, maintainability, and safety (RAMS), wheel life is found to be 930,000 km. The IORE locomotives are equipped with electro-dynamic (ED) brakes, but because of the inability of the contact grid to handle the full regenerative energy from the locomotives, the use of theED-brake was restricted until the contact grid was upgraded in 2010. From around 2011, the wheel life started to decrease because of increased rolling contact fatigue (RCF), dropping to around 350,000 km. LKABsuspected the use of the ED-brake was contributing to the RCF problem. A field test compared one locomotive with ED-braking reduced to a minimum level to a locomotive with full ED-braking capacity. The wheels of the two locomotives were visually inspected at intervals of about 13,000 km. The results showed no difference in RCF performance between the locomotives.
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18. |
- Ramirez, Jorge, et al.
(author)
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Difference in Clinical Presentation between Female and Male Patients with Primary Sjogren's Syndrome at Diagnosis and in Long-Term Follow-up
- 2017
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In: Arthritis & Rheumatology. - : Wiley-Blackwell. - 2326-5191 .- 2326-5205. ; 69
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Journal article (other academic/artistic)abstract
- Background/Purpose: Despite men being less prone to develop autoimmune diseases, male sex has been associated with a more severe disease course in several systemic autoimmune diseases. In the present study, we aimed to identify differences in clinical presentation between the sexes at the time of diagnosis and during long-term follow-up of primary Sjögren's syndrome (pSS), and to establish whether male sex is associated with a more severe form of pSS. Methods: Incident, treatment naïve patients (n=199, 186 females and 13 males) from Stockholm, Sweden were prospectively included during a 5-year period and examined for items of classification criteria for pSS as well as extraglandular manifestations (EGM). Serum was sampled at the time of diagnosis and anti-Ro52/SSA levels measured by ELISA. Replication of significant findings was confirmed in an independent cohort of incident pSS patients from Pisa, Italy (n=377, 368 females and 9 males), and meta-analysis performed. We further studied a cohort of 967 patients with prevalent pSS (899 females and 68 males) from Scandinavian clinical centers. The mean follow-up time (years) was 8.8 ± 7.6 for women and 8.5 ± 6.2 for men (ns). Clinical data including serological and hematological parameters, glandular, EGM and comorbidities were compared between men and women. Results: An increased frequency of EGM in men at diagnosis was observed and replicated (p=0.05, p=0.0003, and pmeta=0.002, respectively). This related to pulmonary involvement, vasculitis and lymphadenopathy being more common in men, for whom a lower age at diagnosis was observed in the exploratory cohort. Additionally, SSA positive male patients had significantly higher levels of anti-Ro52 levels than their female counterparts (p=0.02). After long-term follow-up, male patient serology was characterized by more frequent positivity for anti-SSA and anti-SSB (p=0.02), and ANA (p=0.02). Also, men with pSS were more frequently diagnosed with interstitial lung disease (p=0.008), lymphadenopathy (p=0.04) and lymphoma (p=0.007). Conversely, concomitant hypothyroidism was more common among female patients (p=0.009). Conclusion: Our analysis of two independent cohorts of incident pSS and a large cohort of prevalent pSS demonstrates significant differences between women and men with pSS. Notably, men present with more EGM, enhanced serological profile and a higher frequency of lymphoma development.
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24. |
- Sepulveda, Jorge I. Ramirez, et al.
(author)
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Long-term follow-up in primary Sjögren's syndrome reveals differences in clinical presentation between female and male patients
- 2017
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In: Biology of Sex Differences. - : BioMed Central. - 2042-6410. ; 8
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Journal article (peer-reviewed)abstract
- Background: Despite men being less prone to develop autoimmune diseases, male sex has been associated with a more severe disease course in several systemic autoimmune diseases. In the present study, we aimed to investigate differences in the clinical presentation of primary Sjogren's syndrome (pSS) between the sexes and establish whether male sex is associated with a more severe form of long-term pSS. Methods: Our study population included 967 patients with pSS (899 females and 68 males) from Scandinavian clinical centers. The mean follow-up time (years) was 8.8 +/- 7.6 for women and 8.5 +/- 6.2 for men (ns). Clinical data including serological and hematological parameters and glandular and extraglandular manifestations were compared between men and women. Results: Male patient serology was characterized by more frequent positivity for anti-Ro/SSA and anti-La/SSB (p = 0. 02), and ANA (p = 0.02). Further, men with pSS were more frequently diagnosed with interstitial lung disease (p = 0. 008), lymphadenopathy (p = 0.04) and lymphoma (p = 0.007). Conversely, concomitant hypothyroidism was more common among female patients (p = 0.009). Conclusions: We observe enhanced serological responses and higher frequencies of lymphoma-related extraglandular manifestations in men with pSS. Notably, lymphoma itself was also significantly more common in men. These observations may reflect an aggravated immune activation and a more severe pathophysiological state in male patients with pSS and indicate a personalized managing of the disease due to the influence of the sex of patients with pSS.
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26. |
- Weissenberg, Sarah Y., et al.
(author)
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Identification and Characterization of Post-activated B Cells in Systemic Autoimmune Diseases
- 2019
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In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 10
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Journal article (peer-reviewed)abstract
- Autoimmune diseases (AID) such as systemic lupus erythematosus (SLE), primary Sjogren's syndrome (pSS), and rheumatoid arthritis (RA) are chronic inflammatory diseases in which abnormalities of B cell function play a central role. Although it is widely accepted that autoimmune B cells are hyperactive in vivo, a full understanding of their functional status in AID has not been delineated. Here, we present a detailed analysis of the functional capabilities of AID B cells and dissect the mechanisms underlying altered B cell function. Upon BCR activation, decreased spleen tyrosine kinase (Syk) and Bruton's tyrosine kinase (Btk) phosphorylation was noted in AID memory B cells combined with constitutive co-localization of CD22 and protein tyrosine phosphatase (PTP) non-receptor type 6 (SHP-1) along with hyporesponsiveness to TLR9 signaling, a Syk-dependent response. Similar BCR hyporesponsiveness was also noted specifically in SLE CD27-B cells together with increased PTP activities and increased transcripts for PTPN2, PTPN11, PTPN22, PTPRC, and PTPRO in SLE B cells. Additional studies revealed that repetitive BCR stimulation of normal B cells can induce BCR hyporesponsiveness and that tissue-resident memory B cells from AID patients also exhibited decreased responsiveness immediately ex vivo, suggesting that the hyporesponsive status can be acquired by repeated exposure to autoantigen(s) in vivo. Functional studies to overcome B cell hyporesponsiveness revealed that CD40 co-stimulation increased BCR signaling, induced proliferation, and downregulated PTP expression (PTPN2, PTPN22, and receptor-type PTPs). The data support the conclusion that hyporesponsiveness of AID and especially SLE B cells results from chronic in vivo stimulation through the BCR without T cell help mediated by CD40-CD154 interaction and is manifested by decreased phosphorylation of BCR-related proximal signaling molecules and increased PTPs. The hyporesponsiveness of AID B cells is similar to a form of functional anergy.
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