@article {Goharjrheum.170438, author = {Faekah Gohar and Janneke Anink and Halima Moncrieffe and Lisette W.A. Van Suijlekom-Smit and Femke H.M. Prince and Marion A.J. van Rossum and Koert M. Dolman and Esther P.A.H. Hoppenreijs and Rebecca ten Cate and Simona Ursu and Lucy R. Wedderburn and Gerd Horneff and Michael Frosch and Dirk Foell and Dirk Holzinger}, title = {S100A12 Is Associated with Response to Therapy in Juvenile Idiopathic Arthritis}, elocation-id = {jrheum.170438}, year = {2018}, doi = {10.3899/jrheum.170438}, publisher = {The Journal of Rheumatology}, abstract = {Objective Around one-third of patients with juvenile idiopathic arthritis (JIA) fail to respond to first-line methotrexate (MTX) or anti-tumor necrosis factor (TNF) therapy, with even fewer achieving >= American College of Rheumatology Pediatric 70\% criteria for response (ACRpedi70), though individual responses cannot yet be accurately predicted. Because change in serum S100-protein myeloid-related protein complex 8/14 (MRP8/14) is associated with therapeutic response, we tested granulocyte-specific S100-protein S100A12 as a potential biomarker for treatment response. Methods S100A12 serum concentration was determined by ELISA in patients treated with MTX (n = 75) and anti-TNF (n = 88) at baseline and followup. Treatment response (>= ACRpedi50 score), achievement of inactive disease, and improvement in Juvenile Arthritis Disease Activity Score (JADAS)-10 score were recorded. Results Baseline S100A12 concentration was measured in patients treated with anti-TNF [etanercept n = 81, adalimumab n = 7; median 200, interquartile range (IQR) 133{\textendash}440 ng/ml] and MTX (median 220, IQR 100{\textendash}440 ng/ml). Of the patients in the anti-TNF therapy group, 74 (84\%) were also receiving MTX. Responders to MTX (n = 57/75) and anti-TNF (n = 66/88) therapy had higher baseline S100A12 concentration compared to nonresponders: median 240 (IQR 125{\textendash}615) ng/ml versus 150 (IQR 87{\textendash}233) ng/ml, p = 0.021 for MTX, and median 308 (IQR 150{\textendash}624) ng/ml versus 151 (IQR 83{\textendash}201) ng/ml, p = 0.002, for anti-TNF therapy. Followup S100A12 could be measured in 44/75 MTX-treated patients (34/44 responders) and 39/88 anti-TNF-treated patients (26/39 responders). Responders had significantly reduced S100A12 concentration (MTX: p = 0.031, anti-TNF: p \< 0.001) at followup versus baseline. Baseline serum S100A12 in both univariate and multivariate regression models for anti-TNF therapy and univariate analysis alone for MTX therapy was significantly associated with change in JADAS-10. Conclusion Responders to MTX or anti-TNF treatment can be identified by higher pretreatment S100A12 serum concentration levels.}, issn = {0315-162X}, URL = {https://www.jrheum.org/content/early/2018/01/05/jrheum.170438}, eprint = {https://www.jrheum.org/content/early/2018/01/05/jrheum.170438.full.pdf}, journal = {The Journal of Rheumatology} }