Complement Protein Levels Reflect Disease Activity in Juvenile Idiopathic Arthritis

Mia Glerup¹, Steffen Thiel ², Veronika Rypdal ³, Ellen Dalen Arnstadt ⁴, Maria Ekelund ⁵, Suvi Peltoniemi ⁶, Kristiina Aalto ⁶, Marite Rygg ⁷, Susan Nielsen ⁸, Anders Fasth ⁹, Lillemor Berntson ¹⁰, Ellen Nordal ³ and Troels Herlin ¹¹, ¹Dept of Pediatrics, Aarhus University Hospital, Aarhus, Denmark, Aarhus, Denmark, ²Department of Biomedicine, Aarhus University, Aarhus, Denmark, Aarhus, Denmark, ³Department of Pediatrics, University Hospital of North Norway, and Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway., Tromsø, Norway, ⁴Department of Clinical and Molecular Medicine, NTNU - Norwegian University of Science and Technology, and Department of Pediatrics, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway., Trondheim, Norway, ⁵Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden. Department of Pediatrics, Ryhov County Hospital, Jonkoping, Sweden., Jonkoping, Sweden, ⁶Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland., Helsinki, Finland, ⁷Department of Clinical and Molecular Medicine, NTNU - Norwegian University of Science and Technology and Department of Pediatrics, St. Olavs Hospital, Trondheim, Norway., Tromsø, Norway, ⁸Department of Pediatrics, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark., Copenhavn, Denmark, ⁹Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden., Gothenburg, Sweden, ¹⁰Department of Women’s and Children’s Health, Uppsala University, Uppsala, Sweden., Uppsala, Sweden, ¹¹Department of Pediatrics, Aarhus University Hospital, Aarhus, Denmark., Aarhus, Denmark

Meeting: 2019 ACR/ARP Annual Meeting

Keywords: complement and longitudinal studies, juvenile idiopathic arthritis (JIA)

Session Information

Date: Sunday, November 10, 2019

Title: Pediatric Rheumatology – ePoster I: Basic Science, Biomarkers, & Sclerodermic Fever

Session Type: Poster Session (Sunday)

Session Time: 9:00AM-11:00AM

Background/Purpose: There is an increasing body of evidence that inadequately controlled activation of complement factors leading to either overactivity or deficiency may be involved in the pathogenesis of some autoimmune diseases. However, the role of the complement system in juvenile idiopathic arthritis (JIA)is still not fully elucidated.The aims of this study were to determine the serum levels of the lectin pathway proteins early in the disease course and 17 years after disease onset and to correlate the protein levels to markers of disease activity in participants from a population-based Nordic JIA cohort. Additionally, we aimed to assess the predictive value of lectin pathway proteins with respect to remission status.

Methods: A population-based cohort study ofconsecutive cases of JIA with a disease onset from 1997-2000 from defined geographical areas of Finland, Sweden, Norway and Denmark with 17 years of follow-up was performed. Clinical characteristics were registered and H-ficolin, M-ficolin, MASP-1, MASP-3, MBL and CL-K1 levels in serum were analyzed.

Results: In total, 293 patients with JIA and available blood samples were included (mean age 23.7 ± 4.4 years; mean follow-up 17.2 ± 1.7 years). Further clinical characteristics of the participants at the 17-year follow-up are reported in Table 1.Concentrations of the lectin proteins in serum were higher at baseline compared to the levels 17 years after disease onset (p≤0.006, n=164). At baseline, the highest level of M-ficolin was observed in systemic JIA, which was significantly higher than in the oligoarticular persistent (p=0.024), polyarticular RF neg (p=0.048), ERA (p=0.02) and the undifferentiated categories (p=0.014) (Figure 1). Conversely, MASP-1 levels at baseline were significantly lower for the systemic group compared to the oligoarticular persistent (p=0.03) and the undifferentiated categories (p=0.019).

Further, high M-ficolin levels at baseline and at 17-year follow-up were correlated to high levels of ESR (Table 2). In contrast, high MASP-1 and MASP-3 tended to correlate to low ESR. CL-K1 showed a negative correlation to JADAS71 at baseline.

None of the protein levels had prognostic abilities with respect to remission or inactive disease status 17 years after disease onset.

Conclusion: We hypothesize that increased serum M-ficolin levels are associated with higher disease activity in JIA and further, the results indicate that MASP-1, MASP-3 and CL-K1 negatively correlated to markers of inflammation.

Table 1

Table 1 Clinical characteristics of participants in the Nordic JIA cohort at the 17-year follow-up visit.

Table 2

Table 2 Correlation between disease activity and lectin levels at baseline and 17-years of follow-up.

Figure 1

Figure 1 Distribution of M-ficolin -a- and MASP-1 -b- levels at baseline among the different JIA categories.

Disclosure: M. Glerup, None; S. Thiel, None; V. Rypdal, None; E. Arnstadt, None; M. Ekelund, None; S. Peltoniemi, None; K. Aalto, None; M. Rygg, None; S. Nielsen, None; A. Fasth, None; L. Berntson, None; E. Nordal, None; T. Herlin, None.

To cite this abstract in AMA style:

Glerup M, Thiel S, Rypdal V, Arnstadt E, Ekelund M, Peltoniemi S, Aalto K, Rygg M, Nielsen S, Fasth A, Berntson L, Nordal E, Herlin T. Complement Protein Levels Reflect Disease Activity in Juvenile Idiopathic Arthritis [abstract]. Arthritis Rheumatol. 2019; 71 (suppl 10). https://acrabstracts.org/abstract/complement-protein-levels-reflect-disease-activity-in-juvenile-idiopathic-arthritis/. Accessed .

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