25rhk127 10.3205/25rhk127 urn:nbn:de:0183-25rhk1277 Meeting Abstract Müller Müller Annika A

Klinik und Poliklinik für Endokrinologie, Nephrologie und Rheumatologie, Rheumatologie, Leipzig

author Braune Braune Laurin L

Klinik und Poliklinik für Endokrinologie, Nephrologie und Rheumatologie, Rheumatologie, Leipzig

author Opitz Opitz Linda L

Klinik und Poliklinik für Kinder- und Jugendmedizin, pädiatrische Immunologie, Kinderrheumatologie und -infektiologie, Leipzig

author Dunst Dunst Franziska F

Klinik und Poliklinik für Kinder- und Jugendmedizin, pädiatrische Immunologie, Kinderrheumatologie und -infektiologie, Leipzig

author Kalenda Kalenda Agnes A

Klinik und Poliklinik für Kinder- und Jugendmedizin, pädiatrische Immunologie, Kinderrheumatologie und -infektiologie, Leipzig

author Kharboutli Kharboutli Laura L

Klinik und Poliklinik für Kinder- und Jugendmedizin, pädiatrische Immunologie, Kinderrheumatologie und -infektiologie, Leipzig

author Klemann Klemann Christian C

Klinik und Poliklinik für Kinder- und Jugendmedizin, pädiatrische Immunologie, Kinderrheumatologie und -infektiologie, Leipzig

author Wagner Wagner Ulf U

Klinik und Poliklinik für Endokrinologie, Nephrologie und Rheumatologie, Rheumatologie, Leipzig

author Rothe Rothe Kathrin K

Klinik und Poliklinik für Endokrinologie, Nephrologie und Rheumatologie, Rheumatologie, Leipzig

author German Medical Science GMS Publishing House

Düsseldorf

610 20250917 engl This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). M0627 127 Deutsche Gesellschaft für Rheumatologie Deutsche Gesellschaft für Orthopädische Rheumatologie 53. Kongress der Deutschen Gesellschaft für Rheumatologie (DGRh), 39. Jahrestagung der Deutschen Gesellschaft für Orthopädische Rheumatologie (DGORh) Deutscher Rheumatologiekongress 2025 Kinderrheumatologie Wiesbaden 20250917 20250920 KI.04 TextIntroduction: Juvenile idiopathic arthritis (JIA) describes a heterogeneous group of several subtypes of chronic, autoimmune diseases characterized by an ongoing inflammation of the joints under the age of 16 . While the subtypes differ in symptoms, therapy and pathogenesis, research has established a crucial role of CD4+ T cells in the pathogenesis of multiple subtypes . SLAMF7 is a marker found on immune cells like NK cells and CD8+ T cells and is associated with cytotoxicity , . Since cytotoxic CD4+ T cell populations (CD4 CTL) play an increasing role in inflammatory diseases, we were interested if CD4 CTLs are already detectable in JIA.Methods: We isolated peripheral blood mononuclear cells (PBMCs) of children with JIA and a healthy age matched control group (HC) by using Ficoll density gradient. The PBMCs were stained for expression of surface markers (CD3, CD8, CD4, SLAMF7, CCR7, CD27, HLA-DR) and the intracellular marker Granzyme A. Cells were acquired on FACS LSR Fortessa (BD Biosciences) and analyzed using FlowJo V10 software.Results: CD4+ T cells of children with JIA (n=27, p= 0.0202) showed a significantly higher expression of SLAMF7 on the surface compared to HC (n=3). Next, we analyzed SLAMF7+ on naïve, central memory and effector-memory CD4+ T cells, based on the expression of CCR7 and CD27. Especially naïve CD4+ T cells (CCR7+CD27+), showed a significantly higher expression of SLAMF7 in contrast to naïve CD4+ T cells of HC. Furthermore, SLAMF7+CD4+ T cells revealed a higher expression of Granzyme A and activation marker HLA-DR than their SLAMF7-CD4+ T cell counterparts and CD4+ T cells of HC.Conclusion: In summary, we found an increased SLAMF7+CD4+ T cell population with potentially cytotoxic features. Since, SLAMF7 can act as an inhibitor or activator for immune cells, further investigations are necessary to examine the role of SLAMF7+CD4+ T cells in the pathogenesis of JIA. The association between SLAMF7 expression and increased Granzyme A and HLA-DR levels implies that SLAMF7 may play a role in regulating T cell activation and effector functions in both health and disease states. To enhance our comprehension of this mechanism, an analysis of synovial fluid would be beneficial.Disclosures: The authors and I declare that the research was conducted in the absence of financial or commercial relationships that could be construed as a potential conflict of interest. Ravelli A Martini A Juvenile idiopathic arthritis 2007 Lancet 767-78 Ravelli A, Martini A. Juvenile idiopathic arthritis. Lancet. 2007 Mar 3;369(9563):767-78. DOI: 10.1016/S0140-6736(07)60363-8 http://dx.doi.org/10.1016/S0140-6736(07)60363-8 Zaripova LN Midgley A Christmas SE Beresford MW Baildam EM Oldershaw RA Juvenile idiopathic arthritis: from aetiopathogenesis to therapeutic approaches 2021 Pediatr Rheumatol Online J 135 Zaripova LN, Midgley A, Christmas SE, Beresford MW, Baildam EM, Oldershaw RA. Juvenile idiopathic arthritis: from aetiopathogenesis to therapeutic approaches. Pediatr Rheumatol Online J. 2021 Aug 23;19(1):135. DOI: 10.1186/s12969-021-00629-8 http://dx.doi.org/10.1186/s12969-021-00629-8 Malaer JD Marrufo AM Mathew PA 2B4 (CD244, SLAMF4) and CS1 (CD319, SLAMF7) in systemic lupus erythematosus and cancer 2019 Clin Immunol 50-6 Malaer JD, Marrufo AM, Mathew PA. 2B4 (CD244, SLAMF4) and CS1 (CD319, SLAMF7) in systemic lupus erythematosus and cancer. Clin Immunol. 2019 Jul;204:50-6. DOI: 10.1016/j.clim.2018.10.009 http://dx.doi.org/10.1016/j.clim.2018.10.009 Gutierrez-Guerrero A Mancilla-Herrera I Maravillas-Montero JL Martinez-Duncker I Veillette A Cruz-Munoz ME SLAMF7 selectively favors degranulation to promote cytotoxicity in human NK cells 2022 Eur J Immunol 62-74 Gutierrez-Guerrero A, Mancilla-Herrera I, Maravillas-Montero JL, Martinez-Duncker I, Veillette A, Cruz-Munoz ME. SLAMF7 selectively favors degranulation to promote cytotoxicity in human NK cells. Eur J Immunol. 2022 Jan;52(1):62-74. DOI: 10.1002/eji.202149406 http://dx.doi.org/10.1002/eji.202149406 0 0 0 0