Increased plasma levels of IL-21 and IL-23 in spondyloarthritis are not associated with clinical and MRI findings.
We have investigated the role of the Th17-related cytokines interleukin-17A (IL-17A), IL-21, and IL-23 in spondyloarthritis (SpA) by examining their association with disease activity and magnetic resonance imaging (MRI) findings in patients with SpA (n = 80). Furthermore, to investigate the cellular origins of the cytokines, paired mononuclear cells from blood and synovial fluid were examined for the expression of IL-17A, IL-21, and IL-23R using multicolor flow cytometry. Both IL-21 and IL-23 levels were increased in plasma from SpA patients compared with healthy volunteers (P < 0.05), whereas IL-17A was not. A significant correlation was observed between individual levels of IL-21 and IL-23 (r = 0.7, P < 0.001). No association between individual levels of IL-17A, IL-21, and IL-23 with C-reactive protein (CRP), MRI changes, and clinical scoring (BASMI, BASFI, and BASDAI) were observed. The frequency of CD4+CD45RO+ T cells expressing IL-21 and IL-23R was increased in the inflamed SpA joint compared to peripheral blood (P < 0.05). This study demonstrate that the plasma levels of the Th17-related cytokines IL-21 and IL-23, but not IL-17A, are increased in SpA patients, but we did not find evidence that the level of these cytokines reflect disease activity in SpA.
Department of Medical Microbiology and Immunology, Aarhus University, Building 1240, Wilhelm Meyers Allé 4, 8000 Aarhus, Denmark.
Thomas
T
Andersen
Tue Kruse
TK
Rasmussen
Malene
M
Hvid
Christian Kanstrup
CK
Holm
Karen Jong-Nyo Berenth
KJ
Madsen
Anne Grethe
AG
Jurik
Marianne
M
Hokland
Kristian
K
Stengaard-Pedersen
Berit
B
Schiøttz-Christensen
Bent
B
Deleuran
D000328:Adult; D005260:Female; D006801:Humans; D020381:Interleukin-17 / Q000096:biosynthesis / Q000097:blood; D053759:Interleukin-23 / Q000097:blood*; D007378:Interleukins / Q000096:biosynthesis / Q000097:blood*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D013167:Spondylitis, Ankylosing / Q000097:blood* / Q000276:immunology / Q000473:pathology*; D015854:Up-Regulation / Q000276:immunology; D000098546:Interleukin-21
C508717:IL17A protein, human; D020381:Interleukin-17; D053759:Interleukin-23; D007378:Interleukins; D000098546:Interleukin-21