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45. Kongress der Deutschen Gesellschaft für Rheumatologie, 31. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie, 27. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie

06.09. - 09.09.2017, Stuttgart

Complement activation profiles in juvenile idiopathic arthritis

Meeting Abstract

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  • Jürgen Brunner - Medizinische Universität Innsbruck, Department für Kinder- und Jugendheilkunde, Innsbruck, Österreich
  • Thomas Giner - Medizinische Universität Innsbruck, Department für Kinder- und Jugendheilkunde, Innsbruck, Österreich
  • Lukas Hackl - Medizinische Universität Innsbruck, Department für Kinder- und Jugendheilkunde, Innsbruck, Österreich

Deutsche Gesellschaft für Rheumatologie. Deutsche Gesellschaft für Orthopädische Rheumatologie. Gesellschaft für Kinder- und Jugendrheumatologie. 45. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh), 31. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh), 27. Jahrestagung der Gesellschaft für Kinder- und Jugendrheumatologie (GKJR). Stuttgart, 06.-09.09.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocKR.32

doi: 10.3205/17dgrh149, urn:nbn:de:0183-17dgrh1496

Published: September 4, 2017

© 2017 Brunner et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Background: Juvenile idiopathic arthritis (JIA) summarizes a group of phenotypically heterogeneous chronic inflammatory disease of childhood. The innate immunity is playing a role in the pathogenesis of JIA. Complement is activated by three pathways (classical pathway (CP), lectin pathway (LP) and alternative pathway (AP)). The role of the complement system in the pathogenesis of JIA is still unclear.

Methods: Peripheral blood samples (PB) (n=158) of 57 pediatric JIA patients were analyzed for specific complement pathway activation (COMPL300 ELISA), complement factor H (CFH)-autoantibodies (CFHAb ELISA) and the soluble MAC (sC5b-9 ELISA) in serum (S) and EDTA-plasma (P)- The JIA subgroups were persistent Oligoarthritis (perOA, n=19), extended Oligoarthritis (extOA, n=8), rheumatoid factor positive Polyarthritis (PARF+, n=4) and negative Polyarthritis (PARF-, n=12) polyarthritis, Enthesitis related arthritis (ERA, n=4); Psoriatic arthritis (PsA, n=3) and systemic JIA (sJIA, n=7). As control group We tested healthy adults (n=100) and children (n=18) without inflammatory diseases. JADAS10 Score defined acute phase of disease.

Results: JIA patients within acute phase of disease (n=53) showed lower capacity in CP (82% [38-97% IQR] vs 104% [97-115% IQR] (p<0.001)) and AP (34% [2-97% IQR] vs 85% [70-99% IQR] (p<0.001)) compared to the control group in median. This can be concluded to chronic over activation in the two complement pathways even though The: in plasma 3,46 AU/ml and serum 19,55 AU/mlonly 40% (29/53) in CP and 36% (26/53) in AP were below the published pathological threshold. Also sMAC was elevated (P 2.3 [1.27-3.43IQR] vs 1.2 [0.84-1.84] AU/ml) in patients with decreased AP in acute phase (p<0.009) compared to the control group. No evidence of CFH-autoantibodies was found in our study group. The sMAC levels were significantly (p<0,009) higher in sera (15.5 [12.03-20.91 IQR] AU/ml) and plasma (1.75 [0.9-3.46 IQR] AU/ml) compared to the control group (S 7.78 [4.9-10.32 IQR] AU/ml, P 1.22 [0.78-1.81 IQR] AU/ml) in the patients with extended and persistent OA, in PARF+ and ERA but not in PARF-, PsA and sJIA.

Conclusion: Special groups of JIA showed increased CS activation with elevated levels of MAC in PB in acute phase of disease. The additional decreased capacity in the CP and AP suppose that the complement system as an additional contributor in pathogenesis and/or course of the acute disease. Therefore the testing of COMPL300 in combination with sMAC could be a helpful biomarker for acute JIA disease and furthermore the pharmaceutical blockage of parts of the complement system might be a therapeutical option in therapy resistant patients.