About the Nordic JIA Study Group (NoSPeR)

NoSPeR is a study group currently working on Nordic population-based follow-up study on juvenile idiopathic arthritis (JIA).

The participating countries are Denmark, Finland, Norway, and Sweden.

The patients were enrolled between the years1997-2000.

The main targets of the study were to achieve more information about the epidemiology, outcome and disease characteristics of JIA.

At first the study was planned for 8 years’ period focusing mainly on disease activity and possible damages related to it. Later it was prolonged until 17-year follow-up, the results of which are currently being analyzed.

Clinical risk factors and biomarkers of JIA-associated uveitis have also been studied.

The study has already resulted in several publications in central international journals of rheumatology.

This Nordic JIA study is prospective longitudinal JIA-study that began in the late 1990s. There were originally 500 children in the Nordic countries (Denmark, Finland, Norway, and Sweden) during the 3-year collection period, see the map for the areas in detail. The first published results concerned the incidence of arthritis in children, as well as the nature of the disease. The incidence of JIA in the Nordic countries was found to be similar to that in other Western countries.

In the eight year study we focused on the disease progression and prognosis. Chronic nature of the disease came up. 440 children (88%) had follow-up for more than 7 years (an average of 5 visits). Clinical data and disease activity were recorded during these monitoring visits according a specific protocol. 66% were girls, the median age at the beginning of the disease was 6 years and about half of the patients had a diagnosis of oligoarthritis at the 6-month-visit. Uveitis developed in the follow-up to 20% of these JIA patients.

Approximately half of the patients had ongoing medication after 8 years of the disease onset. On the other hand, almost half of the patients were in remission without medication.

Nearly one third of these children were still on regular medication, and 58% had used rheumatic drugs (DMARDs) at some point during the follow-up. One fifth of the patients had some JIA-related damage. 58% of patients were not in remission without mediaction at the final visit, of which 9% were in remission on medication, and 42% were in remission without medication. Most patients who were in remission, had remained in the oligoarthritis group or were those patients in systemic JIA - group of patients who had not developed a polyarticular disease.

The NoSPeR- follow-up study exposed the chronicity of JIA, when more than half of the children were not in remission without medication eight years after the disease onset.

The purpose of a 17-year follow-up study is to examine further the prognosis of the disease. The aims are to clarify the characteristics of the disease, intensely, as well as the medications and disease burden. The aim is to assess the damages of a permanent nature, related to the disease, and on the other hand, how many are in remission.

The NoSPeR study has produced the material for two dissertations, one by Dr. Lillemor Berntson, in Sweden (2003), and the other by Dr. Ellen Nordal in Norway (2011). There are also many other publications in international journals of rheumatology (see also the “Publications” sector). There have been numerous abstracts and presentations in the international rheumatology congresses for example PRES (the Pediatric Rheumatology European Society) and EULAR (the European League Against Rheumatism).

Thesis:

Berntson L. JIA (juvenile idiopathic arthritis) in the Nordic countries. Aspects of classification, epidemiology and pain assessment: Thesis. Göteborg University, 2003.

Nordal, E. Disease activity and outcome in juvenile idiopathic arthritis; a longitudinal cohort study in the Nordic countries: Thesis. University of Tromsø, 2011.

Glerup M. Long-term outcomes of Juvenile Idiopathic Arthritis (JIA):18 years of follow-up in the population-based Nordic JIA cohort. Thesis. Aarhus University, 2019.

Arnstad, E. D. Pain and Fatigue in Young Adults with Juvenile Idiopathic Arthritis – Based on A Nordic Prospective Longitudinal Study. Thesis. Norwegian University of Science and Technology (NTNU), 2020.

Rypdal V. Prediction of unfavorable outcome in Juvenile Idiopathic Arthritis (JIA) and assessment of the long-term outcomes in JIA-associated uveitis – A prospective Nordic multicenter study of JIA from childhood to adulthood. Thesis. University Hospital of North Norway, 2021.

Publications:

Construct validity of ILAR and EULAR criteria in juvenile idiopathic arthritis: a population based incidence study from the Nordic countries. International League of Associations for Rheumatology. European League Against Rheumatism. Berntson L, Fasth A, Andersson-Gäre B, Kristinsson J, Lahdenne P, Marhaug G, Nielsen S, Pelkonen P, Svensson E; Nordic Study Group. J Rheumatol. 2001 Dec;28(12):2737-43.

The influence of heredity for psoriasis on the ILAR classification of juvenile idiopathic arthritis. Berntson L, Fasth A, Andersson-Gäre B, Herlin T, Kristinsson J, Lahdenne P, Marhaug G, Nielsen S, Pelkonen P, Rygg M. J Rheumatol. 2002 Nov;29(11):2454-8.

Incidence of juvenile idiopathic arthritis in the Nordic countries. A population based study with special reference to the validity of the ILAR and EULAR criteria. Berntson L, Andersson Gäre B, Fasth A, Herlin T, Kristinsson J, Lahdenne P, Marhaug G, Nielsen S, Pelkonen P, Rygg M; Nordic Study Group. J Rheumatol. 2003 Oct;30(10):2275-82.

Assessment of disease activity in juvenile idiopathic arthritis. The number and the size of joints matter. Berntson L, Wernroth L, Fasth A, Aalto K, Herlin T, Nielsen S, Nordal E, Rygg M, Zak M. J Rheumatol. 2007 Oct;34(10):2106-11. Epub 2007 Sep 15.

HLA-B27 predicts a more extended disease with increasing age at onset in boys with juvenile idiopathic arthritis. Berntson L, Damgård M, Andersson-Gäre B, Herlin T, Nielsen S, Nordal E, Rygg M, Zak M, Fasth A; Nordic Paediatric Rheumatology Study Group. J Rheumatol. 2008 Oct;35(10):2055-61. Epub 2008 Sep 1.

Biomarkers of chronic uveitis in juvenile idiopathic arthritis: predictive value of antihistone antibodies and antinuclear antibodies. Nordal EB, Songstad NT, Berntson L, Moen T, Straume B, Rygg M. J Rheumatol. 2009 Aug;36(8):1737-43.

Ongoing disease activity and changing categories in a long-term nordic cohort study of juvenile idiopathic arthritis. Nordal E, Zak M, Aalto K, Berntson L, Fasth A, Herlin T, Lahdenne P, Nielsen S, Straume B, Rygg M; Nordic Study Group of Pediatric Rheumatology. Arthritis Rheum. 2011 Sep;63(9):2809-18.

Validity and predictive ability of the juvenile arthritis disease activity score based on CRP versus ESR in a Nordic population-based setting. Nordal EB, Zak M, Aalto K, Berntson L, Fasth A, Herlin T, Lahdenne P, Nielsen S, Peltoniemi S, Straume B, Rygg M. Ann Rheum Dis. 2012 Jul;71(7):1122-7.

HLA-B27 predicts a more chronic disease course in an 8-year followup cohort of patients with juvenile idiopathic arthritis. Berntson L, Nordal E, Aalto K, Peltoniemi S, Herlin T, Zak M, Nielsen S, Rygg M; Nordic Study Group of Paediatric Rheumatology. J Rheumatol. 2013 May;40(5):725-31.

Anti-type II collagen antibodies, anti-CCP, IgA RF and IgM RF are associated with joint damage, assessed eight years after onset of juvenile idiopathic arthritis (JIA). Berntson L, Nordal E, Fasth A, Aalto K, Herlin T, Nielsen S, Rygg M, Zak M, Rönnelid J. Pediatr Rheumatol Online J. 2014 Jun 11;12:22.

Psoriasis and associated variables in classification and outcome of juvenile idiopathic arthritis - an eight-year follow-up study. Ekelund M, Aalto K, Fasth A, Herlin T, Nielsen S, Nordal E, Peltoniemi S, Rygg M, Zak M, Berntson L; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Pediatr Rheumatol Online J. 2017 Feb 22;15(1):13. 

Ankle arthritis predicts polyarticular disease course and unfavourable outcome in children with juvenile idiopathic arthritis. Esbjörnsson AC, Aalto K, Broström EW, Fasth A, Herlin T, Nielsen S, Nordal E, Peltoniemi S, Rygg M, Zak M, Berntson L; Nordic Study Group of Paediatric Rheumatology (NoSPeR). Clin Exp Rheumatol. 2015 Sep-Oct;33(5):751-7.

A survey of national and multi-national registries and cohort studies in juvenile idiopathic arthritis: challenges and opportunities. Timothy Beukelman, Janneke Anink, Lillemor Berntson, Ciaran Duffy, Justine A. Ellis, Mia Glerup, Jaime Guzman, Gerd Horneff, Lianne Kearsley-Fleet, Ariane Klein, Jens Klotsche, Bo Magnusson, Kirsten Minden, Jane E. Munro, Martina Niewerth, Ellen Nordal, Nicolino Ruperto, Maria Jose Santos, Laura E. Schanberg, Wendy Thomson, Lisette van Suijlekom-Smit, Nico Wulffraat and Kimme Hyrich; Beukelman et al. Pediatric Rheumatology 2017 April 19, 15:31.

Psoriasis and associated variables in classification and outcome of juvenile idiopathic arthritis - an eight-year follow-up study. M. Ekelund , K. Aalto, A. Fasth , T. Herlin , S. Nielsen, E. Nordal, S. Peltoniemi , M. Rygg , M. Zak, L. Berntson on behalf of Nordic Study Group of Pediatric Rheumatology (NoSPeR). Pediatr Rheumatol Online J. 2017 Feb 22;15(1):13.

Rypdal V, Arnstad ED, Aalto K, Berntson L, Ekelund M, Fasth A, Glerup M, Herlin T, Nielsen S, Peltoniemi S, Zak M, Rygg M, Rypdal M, Nordal E; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Predicting unfavorable long-term outcome in juvenile idiopathic arthritis: results from the Nordic cohort study. Arthritis Res Ther. 2018 May 3;20(1):91.

Nordal E, Rypdal V, Christoffersen T, Aalto K, Berntson L, Fasth A, Herlin T, Nielsen S, Peltoniemi S, Straume B, Zak M, Rygg M; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Incidence and predictors of Uveitis in juvenile idiopathic arthritis in a Nordic long-term cohort study. Pediatr Rheumatol Online J. 2017 Aug 18;15(1):66. 

Arnstad ED, Rypdal V, Peltoniemi S, Herlin T, Berntson L, Fasth A, Nielsen S, Glerup M, Ekelund M, Zak M, Aalto K, Nordal E, Romundstad PR, Rygg M; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Early self-reported pain in juvenile idiopathic arthritis (JIA) is related to long-term outcomes. Results from the Nordic JIA cohort study. Arthritis Care Res (Hoboken). 2018 Jul 28. 

Participation in school and physical education in juvenile idiopathic arthritis in a Nordic long-term cohort study. Nordal E, Rypdal V, Arnstad ED, Aalto K, Berntson L, Ekelund M, Fasth A, Glerup M, Herlin T, Nielsen S, Peltoniemi S, Zak M, Songstad NT, Rygg M; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Pediatr Rheumatol Online J. 2019 Jul 15;17(1):44.

Complement lectin pathway protein levels reflect disease activity in juvenile idiopathic arthritis: a longitudinal study of the Nordic JIA cohort. Glerup M, Thiel S, Rypdal V, Arnstad ED, Ekelund M, Peltoniemi S, Aalto K, Rygg M, Nielsen S, Fasth A, Berntson L, Nordal E, Herlin T; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Pediatr Rheumatol Online J. 2019 Sep 9;17(1):63.

Longterm Outcomes of Temporomandibular Joints in Juvenile Idiopathic Arthritis: 17 Years of Follow up of a Nordic Juvenile Idiopathic Arthritis Cohort. Glerup M, Stoustrup P, Matzen LH, Rypdal V, Nordal E, Frid P, Arnstad ED, Rygg M, Thorarensen O, Ekelund M, Berntson L, Fasth A, Nilsson H, Peltoniemi S, Aalto K, Arte S, Toftedal P, Nielsen S, Kreiborg S, Herlin T, Pedersen TK. J Rheumatol. 2019 Sep 15:jrheum.190231.

Validation of prediction models of severe disease course and non-achievement of remission in juvenile idiopathic arthritis: part 1-results of the Canadian model in the Nordic cohort. Rypdal V, Guzman J, Henrey A, Loughin T, Glerup M, Arnstad ED, Aalto K, Rygg M, Nielsen S, Herlin T, Fasth A, Berntson L, Rypdal M, Nordal E; ReACCh-Out and NoSPeR Investigators. Arthritis Res Ther. 2019 Dec 5;21(1):270.

Long-Term Outcomes in Juvenile Idiopathic Arthritis: Eighteen Years of Follow-Up in the Population-Based Nordic Juvenile Idiopathic Arthritis Cohort. Glerup M, Rypdal V, Arnstad ED, Ekelund M, Peltoniemi S, Aalto K, Rygg M, Toftedal P, Nielsen S, Fasth A, Berntson L, Nordal E, Herlin T; Nordic Study Group of Pediatric Rheumatology. Arthritis Care Res (Hoboken). 2020 Apr;72(4):507-516.

Uveitis in Juvenile Idiopathic Arthritis: 18-year Outcome in the Population-based Nordic Cohort Study. Rypdal V, Glerup M, Songstad NT, Bertelsen G, Christoffersen T, Arnstad ED, Aalto K, Berntson L, Fasth A, Herlin T, Ekelund M, Peltoniemi S, Toftedal P, Nielsen S, Leinonen S, Bangsgaard R, Nielsen R, Rygg M, Nordal E; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Ophthalmology. 2020 Aug 28:S0161-6420(20)30842-3. 

Fatigue in young adults with juvenile idiopathic arthritis 18 years after disease onset: data from the prospective Nordic JIA cohort. Arnstad ED, Glerup M, Rypdal V, Peltoniemi S, Fasth A, Nielsen S, Zak M, Aalto K, Berntson L, Nordal E, Herlin T, Romundstad PR, Rygg M; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Pediatr Rheumatol Online J. 2021 Mar 18;19(1):33.

Transition to adult care in Finnish adolescents with juvenile idiopathic arthritis. Mikola K, Rebane K, Glerup M, Kautiainen H, Relas H, Peltoniemi S, Aalto K. Scand J Rheumatol. 2022 Mar 11:1-5.

Changing Patterns in Treatment, Remission Status, and Categories in a Long-Term Nordic Cohort Study of Juvenile Idiopathic Arthritis. Glerup M, Arnstad ED, Rypdal V, Peltoniemi S, Aalto K, Rygg M, Nielsen S, Fasth A, Berntson L, Nordal E, Herlin T; Nordic Study Group of Pediatric Rheumatology (NoSPeR). Arthritis Care Res (Hoboken). 2022 May;74(5):719-727.

Abdominal pain in Finnish young adults with juvenile idiopathic arthritis. Rebane K, Tuomi AK, Kautiainen H, Peltoniemi S, Glerup M, Aalto K. Scand J Gastroenterol. 2022 May 11:1-6.

Transitioning patients with juvenile idiopathic arthritis to adult care: the Nordic experience. Mikola K, Rebane K, Arnstad ED, Berntson L, Fasth A, Glerup M, Herlin T, Kautiainen H, Nielsen S, Nordal E, Peltoniemi S, Rygg M, Rypdal V, Zak M, Aalto K. Pediatr Rheumatol Online J. 2022 Oct 1;20(1):84. 

Disease characteristics of HLA-B27 positive and negative Finnish patients with juvenile idiopathic arthritis - results of the 18-year cohort follow-up study. Peltoniemi SOO, Glerup M, Lahdenne P, Eklund KK, Aalto K.  Pediatr Rheumatol Online J. 2023 Sep 1;21(1):94. 

 

Abstracts:

  1. Nordal E, Songstad NT, Damgard M, Berntson L, Rygg M. ANA as a risk factor for JIA-associated uveitis is highly dependent of method. XIVth European Pediatric Rheumatology Congres, Istanbul, Turkey, September, 5th-9th, 2007

  2. Berntson L, Wernroth L, Fasth A, Aalto K, Herlin T, Nielsen S, Nordal E, Rygg M, Marek Zak M, for the Nordic Paediatric Rheumatology Study Group. Towards a disease activity score in Juvenile idiopathic arthritis (JIA). The number and the size of joints matters. XIVth European Pediatric Rheumatology Congres, Istanbul, Turkey, September, 5th-9th, 2007

  3. Nordal EB, Songstad NT, Straume B, Damgard M, Berntson L, Rygg M. Antihistone Antibodies and ANA in Children with JIA; Choice of Method Matters. American College of Rheumatology: Keystone Pediatric Rheumatology Symposium, Keystone, 01.-05.03.2008

  4. Nordal EB, Songstad NT, Straume B, Berntson L, Rygg M. May antihistone antibodies replace antinuclear antibodies (ANA) as a predictor of uveitis in Juvenile idiopathic arthritis? XVth European Pediatric Rheumatology Congres, London, September, 14th-17th, 2008 Pediatric Rheumatology 2008, 6 (Suppl 1): P4 (Epub 15 September 2008)

  5. Berntson L, Damgård M, Andersson-Gäre B, Herlin T, Nielsen S, Nordal E, Rygg M, Zak M, Fasth A. HLA-B27 predicts a more extended disease with increasing age at onset in boys with juvenile idiopathic arthritis. 15th Paediatric Rheumatology European Society (PreS) Congress, London, UK. 14–17 September 2008. Pediatric Rheumatology 2008, 6(Suppl 1):P57 (Epub15 September 2008)

  6. Nordal E, Zak M, Berntson L, Aalto K, Peltoniemi S, Nielsen S, Straume B, Fasth A, Rygg M. Disease characteristics and medication during the first eight years after disease onset in a Nordic Juvenile Idiopathic Arthritis (JIA) cohort. 33rd Scandinavian Congress of Rheumatology, Bergen, Norway, 09.-12.05.2010

  7. Nordal E, Zak M, Berntson L, Aalto K, Peltoniemi S, Nielsen S, Herlin T, Straume B, Fasth A, Rygg M. Validation of the Juvenile Arthritis Disease Activity Score (JADAS) based on C-reactive protein in a population-based Nordic cohort of juvenile idiopathic arthritis. 17th Paediatric Rheumatology European Society (PreS) Congress Valencia, Spania, 09.-12. September 2010. Clin Exp Rheumatol, 2011;29:418-419

  8. Nordal E, Zak M, Berntson L, Aalto K, Peltoniemi S, Nielsen S, Herlin T, Straume B, Fasth A, Rygg M. Ongoing disease-activity in a majority of children in a Nordic Juvenile Idiopathic Arthritis (JIA) cohort. 17th Paediatric Rheumatology European Society (PreS) Congress Valencia, Spania, 09.-12. September 2010. Clin Exp Rheumatol, 2011;29:372

  9. Nordal E, Zak M, Berntson L, Aalto K, Lahdenne P, Peltoniemi S, Nielsen S, Herlin T, Straume B, Fasth A, Rygg M. Juvenile Arthritis Disease Activity Score (JADAS) based on CRP; Validity and predictive ability in a Nordic population-based setting.18th Paediatric Rheumatology European Society (PreS) Congress, Brugge, Belgium, September 14th-17th, 2011. Pediatric Rheumatology 2011, 9 (Suppl 1): P155 (14 September 2011).

  10. Nordal E, Zak M, Berntson L, Aalto K, Peltoniemi S, Nielsen S, Herlin T, Straume B, Fasth A, Rygg M. Validation of the Juvenile Arthritis Disease Activity Score (JADAS) based on C-reactive protein in a population-based Nordic cohort of juvenile idiopathic arthritis. the Pediatric Rheumatology Symposium (PRSYM), June 2 – 5, 2011, Miami, Florida. Pediatric Rheumatology 2012, 10 (Suppl 1): A42 (13 July 2012)

  11. Ellen Nordal, Marek Zak, Lillemor Berntson, Kristiina Aalto, Suvi Peltoniemi, Susan Nielsen, Troels Herlin, Pekka Lahdenne, Bjørn Straume, Anders Fasth, Marite Rygg. Ongoing disease-activity and change in ILAR categories in a Nordic juvenile idiopathic arthritis cohort. From 2011 Pediatric Rheumatology Symposium sponsored by the American College of Rheumatology, Miami, FL, USA. 2-5 June 2011. Pediatric Rheumatology 2012, 10 (Suppl 1): A41 (13 July 2012)

  12. Berntson L, Aalto K, Fasth A, Herlin T, Nielsen S, Nordal E, Peltoniemi S, Zak M, Rygg M. HLA-B27 and classification of enthesitis-related arthritis in an eight year follow up study. Oral presentation/ abstract, EULAR PReS congress 2012, Berlin

  13. L Berntson, K Aalto, A Fasth, T Herlin, S Nielsen, E Nordal, M Rygg, J Rönnelid. Anti-type II collagen antibodies, anti-CCP, IgA-RF and IgM-RF are associated with joint damage eight years after onset of juvenile idiopathic arthritis (JIA). From 20th Pediatric Rheumatology European Society (PReS) Congress Ljubljana, Slovenia. 25-29 September 2013. Pediatric Rheumatology 2013, 11 (Suppl 2): P83 (5 December 2013)

  14. EB Nordal, L Berntson, K Aalto, S Peltoniemi, S Nielsen, T Herlin, A Fasth, M Rygg, the Nordic Study Group of Pediatric Rheumatology (NoSPeR) Uveitis in the Nordic juvenile idiopathic arthritis cohort; high incidence, frequent complications, and gender-associated risk factors. From 20th Pediatric Rheumatology European Society (PReS) Congress Ljubljana, Slovenia. 25-29 September 2013. Pediatric Rheumatology 2013, 11 (Suppl 2): P59 (5 December 2013).

  15. Anna-Clara Esbjörnsson, Kristiina Aalto, Eva W Broström, Anders Fasth, Troels Herlin, Susan Nielsen, Ellen Nordal, Marite Rygg, Marek Zak, Lillemor Berntson, Nordic Study Group of Pediatric Rheumatology (NoSPeR). Ankle arthritis predicts worse outcome in children with juvenile idiopathic arthritis. From 21st Pediatric Rheumatology European Society (PReS) Congress, Belgrade, The Serb Republic, 18.-21. September, 2014. Pediatric Rheumatology 2014; 12 (Suppl 1): P33

  16. Alberdi-Saugstrup, Mikel; Berntson, Lillemor; Enevold, Christian; Fasth, Anders; Nielsen, Susan M.; Nordal, Ellen Berit; Rygg, Marite; Zak, Marek S.; Müller, Klaus G..
    Non-HLA genepolymorphisms in juvenile chronic arthritis: Associations with outcome of disease. From 21st Pediatric Rheumatology European Society (PReS) Congress, Belgrade, The Serb Republic, 18.-21. September, 2014. Pediatric Rheumatology 2014; Volum 12. Suppl. 1: P192

  17. Ellen B Nordal, Lillemor Berntson, Kristiina Aalto, Anders Fasth, Troels Herlin, Susan Nielsen, Suvi Peltoniemi, Marek Zak, Marite Rygg, the Nordic Study Group of Pediatric Rheumatology (NoSPeR). Histone antibodies as a biomarker of uveitis in JIA. From 21st Pediatric Rheumatology European Society (PReS) Congress, Belgrade, The Serb Republic, 18.-21. September, 2014. Pediatric Rheumatology 2014; 12 (Suppl 1): O4

  18. Suvi Peltoniemi, Ellen Nordal, Lillemor Berntson, Marite Rygg, Anders Fasth, Troels Herlin, Susan Nielsen, Marek Zak, Kristiina Aalto. Prognostic factors for the disease course and 8-year outcome in Nordic children with oligoarticular-onset juvenile idiopathic arthritis. From 21st Pediatric Rheumatology European Society (PReS) Congress, Belgrade, The Serb Republic, 18.-21. September, 2014. Pediatric Rheumatology 2014; 12 (Suppl 1): P3

  19. E. D. Arnstad, E. Nordal, L. Berntson, K. Aalto, A. Fasth, T. Herlin, S. Nielsen, M. Zak, P. R. Romundstad, M. Rygg. Self-reported pain 6 months after onset of juvenile idiopathic arthritis is related to pain score and disease outcome after 8 years. Annual European Congress of Rheumatology, Fiera di Roma, Rome, Italy, 10 - 13 June 2015, Ann Rheum Dis 2015;74(Suppl 2): 383 THU0507, doi:10.1136/annrheumdis-2015-eular.2391

  20. M. Ekelund , K. Aalto, A. Fasth , T. Herlin , S. Nielsen, E. Nordal, S. Peltoniemi , M. Rygg , M. Zak, L. Berntson on behalf of Nordic Study Group of Pediatric Rheumatology (NoSPeR). Children with psoriasis and arthritis –an important clinical and prognostic issue that challenges the ILAR-classification. EULAR 15-2313, Roma.

  21. Veronika Rypdal, Ellen D Arnstad, Lillemor Berntson, Marek Zak, Kristiina Aalto, Suvi Peltoniemi, Susan Nielsen, Mia Glerup, Troels Herlin, Anders Fasth, Maria Ekelund, Marite Rygg, Ellen Nordal and Nordic Study Group of Pediatric Rheumatology (NoSPeR). Baseline predictors of functional disability eight years after disease onset in the nordic juvenile idiopathic arthritis population-based cohort. Proceedings of the 24th European Paediatric Rheumatology Congress (PReS 2017). Pediatric Rheumatology 2017:15 (Suppl 2):64.

  22. Mia Glerup,  Veronika Rypdal, Ellen Arnstad, Maria Ekelund, Suvi Peltoniemi, Kristiina Aalto, Marite Rygg,  Peter Toftedal, Susan Nielsen, Anders Fasth,  Lillemor Berntson, Ellen Nordal, Troels Herlin for the Nordic Study Group of Pediatric Rheumatology (NoSPeR). Remission status after 18 years of follow-up in the population-based Nordic Juvenile Idiopathic Arthritis (JIA) cohort. Proceedings of the 25th European Paediatric Rheumatology Congress (PReS 2018). Pediatric Rheumatology 2018:16 (Suppl 2):52

  23. Veronika Rypdal, Mia Glerup, Terje Christoffersen, Geir Bertelsen, Ellen Dalen Arnstad, Kristiina Aalto, Suvi Peltoniemi, Lillemor Berntson, Maria Ekelund, Anders Fasth, Troels Herlin, Susan Nielsen, Peter Toftedal, Rasmus Nielsen, Sanna Leinonen, Regitze Bangsgaard, Susanne Lindqvist, Marite Rygg, Ellen Nordal, the Nordic Study Group of Pediatric Rheumatology (NoSPeR). Long-term outcome and complications in uveitis, 18 years after disease onset in a population-based Nordic juvenile idiopathic arthritis cohort. Proceedings of the 25th European Paediatric Rheumatology Congress (PReS 2018). Pediatric Rheumatology 2018:16 (Suppl 2):52.

  24. Disease activity in juvenile idiopathic arthritis from childhood to adulthood in the nordic JIA cohort. V. Rypdal on behalf of Nordic Study Group of Pediatric Rheumatology (NoSPeR), M. Glerup, M. Rypdal, E. D. Arnstad, K. Aalto, L. Berntson, A. Fasth, T. Herlin, S. Nielsen, M. Rygg, E. Nordal. PReS 2022. Pediatric Rheumatology 2022, 20(Suppl 2):75: O24.

  25. Biomarkers related to myeloid derived cells obtained at baseline and at 18-year follow-up in juvenile idiopathic arthritis. relation to remission status and inactive disease. M. Glerup, C. Kessel, D. Foell, M. Høllsberg, L. Berntson, A. Fasth, S. Nielsen, E. Nordal, V. Rypdal, M. Rygg, E. Arnstad, S. Peltoniemi, K. Aalto, T. Herlin on behalf of the Nordic Study Group of Pediatric Rheumatology (NoSPeR).  PReS 2022. Pediatric Rheumatology 2022, 20(Suppl 2):75: P020.

  26. Body mass index is related to disease variables in young adults with juvenile idiopathic arthritis. A.-K. Tuomi, K. Rebane, E. D. Arnstad, L. Berntson, A. Fasth, M. Glerup, T. Herlin, H. Kautiainen, E. Nordal, S. Peltoniemi, M. Rygg, V. Rypdal, M. Zak, K. Aalto. PReS 2022. Pediatric Rheumatology 2022, 20(Suppl 2):75: P082.

  27.  A novel serum calprotectin (MRP8/14) particle enhanced immuno-turbidimetric assay (sCAL turbo) helps to differentiate SJIA from other diseases in routine clinical laboratory settings. Dirk Foell, Melanie Saers, Carolin Park, Ninna Brix, Mia Glerup, Christoph Kessel, Helmut Wittkowski, Claas Hinze, Lillemor Berntson, Anders Fasth, Susan Nielsen, Ellen Nordal, Marite Rygg, Henrik Hasle, Troels Herlin, Dirk Holzinger, Christian Niederberger, Bernhard Schlueter. EULAR 2023. Ann Rheum Dis 2023;82 (Suppl 1).

  28. Inflammatory biomarkers in relation to long-term remission and active disease. A population-based study of the Nordic JIA cohort. M. Glerup, C. Kessel, D. Foell, L. Berntson, A. Fasth, C. Myrup, E. Nordal, V. G. Rypdal, M. Rygg, E. D. Arnstad, S. Peltoniemi, K. Aalto, M. Høllsberg, A. E. Bilgrau, T. Herlin. PReS 2023. Pediatric Rheumatology 2023, 21(Suppl 2):PT013.

  29. Patient’s global assessment of well-being in long-term disease activity: results of 18-years follow-up in the population-based Nordic JIA cohort. V. Rypdal, M. Glerup, M. Rypdal, E. D. Arnstad, K. Aalto, L. Berntson, A. Fasth, T. Herlin, C. Myrup, S. Peltoniemi, M. Rygg, E. Nordal on behalf of the Nordic Study Group of Pediatric Rheumatology (NoSPeR). PReS 2023. Pediatric Rheumatology 2023, 21(Suppl 2):P282.