Search

Objective: We examine levels of candidate blood‐based biomarkers (CBBs) in patients with juvenile idiopathic arthritis (JIA) treated with tofacitinib. Methods: Patients with JIA who participated in clinical trial NCT02592434 received tofacitinib from baseline to week 18. Serial serum samples were assayed for CBBs (S100A8/9, S100A12, interleukin‐18 [IL‐18], serum amyloid A, resistin, vascular endothelial growth factor, angiopoietin‐1, angiopoietin‐2, matrix metalloproteinase 8 [MMP8], MMP2, tissue inhibitor of metalloproteinases 1, leptin, chemokine [C‐X‐C motif] ligand 9, soluble IL‐2 receptor, intercellular adhesion molecule 1, soluble tumor necrosis factor receptor, IL‐6, IL‐23, monocyte chemotactic protein 1, chemokine [C‐C motif] ligand 18 [CCL18], and CCL20). Association of CBBs with JIA response to treatment from baseline to week 18 were assessed. Results: This study included 166 patients with polyarticular‐course JIA. Paired serum samples from 143 patients were available at both baseline and week 18. Thirty‐five percent (50 of 143) of patients had a JIA‐American College of Rheumatology 90 (JIA‐ACR90) level improvement, whereas 90, 121, and 137 (63%, 85%, and 96%) achieved JIA‐ACR70, 50, and 30 improvement at week 18. Despite small numerical differences by JIA category, there were no baseline CBB values that independently predicted a decrease in Juvenile Arthritis Disease Activity Score (JADAS‐27) or JIA‐ACR90 response by week 18. Decrease in resistin level (baseline to week 18) was significantly associated with week 18 improvement in JADAS‐27 and JIA‐ACR90 response after adjusting for age, sex, JIA disease duration, and baseline resistin (r2 0.79, SE 0.070, P < 0.01, and odds ratio [95% confidence interval] 1.134 [1.018–1.264]). HLA‐B27 positivity was significantly associated with not achieving a JIA‐ACR90 response at week 18 (P = 0.0097). Conclusion: Among the CBBs included, only resistin was significantly associated with treatment response, and no CBB was identified that forecasts JIA improvement after initiation of tofacitinib. The association of HLA‐B27 positivity with lower response to tofacitinib in JIA is intriguing and merits further study. [ABSTRACT FROM AUTHOR]

Obesity promotes a chronic inflammatory and hypercoagulable state that drives cardiovascular disease, type 2 diabetes, fatty liver disease, and several cancers. Elevated thrombin activity underlies obesity-linked thromboembolic events, but the mechanistic links between the thrombin/fibrin(ogen) axis and obesity-associated pathologies are incompletely understood. In this work, immunohistochemical studies identified extravascular fibrin deposits within white adipose tissue and liver as distinct features of mice fed a high-fat diet (HFD) as well as obese patients. Fib[[gamma].sup.390-396A] mice carrying a mutant form of fibrinogen incapable of binding leukocyte [[alpha].sub.M][[beta].sub.2]-integrin were protected from HFD-induced weight gain and elevated adiposity. Fib[[gamma].sup.390-396A] mice had markedly diminished systemic, adipose, and hepatic inflammation with reduced macrophage counts within white adipose tissue, as well as near-complete protection from development of fatty liver disease and glucose dysmetabolism. Homozygous thrombomodulin-mutant [Thbd.sup.Pro] mice, which have elevated thrombin procoagulant function, gained more weight and developed exacerbated fatty liver disease when fed a HFD compared with WT mice. In contrast, treatment with dabigatran, a direct thrombin inhibitor, limited HFD-induced obesity development and suppressed progression of sequelae in mice with established obesity. Collectively, these data provide proof of concept that targeting thrombin or fibrin(ogen) may limit pathologies in obese patients., Introduction Obesity is a health care crisis of global pandemic status, with an estimated 34% of adults and 17% of children in the United States classified as obese as defined [...]

Fibrin deposition within joints is a prominent feature of arthritis, but the precise contribution of fibrin(ogen) to inflammatory events that cause debilitating joint damage remains unknown. To determine the importance [...]

A biosafety plan is essential to establish appropriate practices for biosafety in a shared resource laboratory (SRL). A biosafety plan will contain the essential information for the use of biological samples on specific instrumentation, their apparent risks, and the steps that should be taken to mitigate these risks. Establishment of a biosafety plan can be a daunting task as the variety of pathogens that come through the SRL is highly diverse and may change over time; however, having a plan that can adapt to this variety will provide a framework for addressing concerns and educating personnel and users on biosafety practices. Using resources available at your institution and developing a robust relationship with health and safety personnel at your institution is key to generating an effective biosafety plan. Here we provide a basic underlying structure for a biosafety plan to aid SRL personnel in generating or maintaining their biosafety procedures, and provide guidance for establishing a dynamic, living biosafety plan. [ABSTRACT FROM AUTHOR]

Purpose: Biomarkers for juvenile idiopathic arthritis-associated uveitis (JIA-U) are needed. We aimed to measure inflammatory biomarkers in tears as a non-invasive method to identify biomarkers of uveitis activity.Methods: Tears were collected from children with JIA-U (n=20) and pediatric controls (n=20) using Schirmer strips. S100A8, A9, A12, IL-18, IL-8, IP-10, MCP-1, RANTES, and sICAM-1 were measured by ELISA and Luminex assays. Levels of biomarkers were compared between children with JIA-U and controls, and active and inactive JIA-U.Results: IL-8, sICAM-1, and S100A12 levels were similar between JIA-U and controls, but differed by activity. Active JIA-U had significantly increased S100A12 compared to inactive JIA-U (mean 27,722.5 pg/ML (SE 1.3) vs. 5,937.2 (1.3), p=0.002), IL-8 (73.5 [1.2] vs. 36.2 [1.2], p=0.009), and sICAM-1 (15,822.7 [1.2) vs. 8,778.0 [1.6], p=0.024).Conclusion: We detected inflammatory biomarkers non-invasively in tears of children with JIA-U. IL-8, sICAM-1, and S100A12 are potential biomarkers for uveitis activity. [ABSTRACT FROM AUTHOR]

Objectives: Systemic juvenile idiopathic arthritis (SJIA) confers high risk for macrophage activation syndrome (MAS), a life-threatening cytokine storm driven by interferon (IFN)-γ. SJIA monocytes display IFN-γ hyper-responsiveness, but the molecular basis of this remains unclear. The objective of this study is to identify circulating monocyte and bone marrow macrophage (BMM) polarisation phenotypes in SJIA including molecular features contributing to IFN response.Methods: Bulk RNA-seq was performed on peripheral blood monocytes (n=26 SJIA patients) and single cell (sc) RNA-seq was performed on BMM (n=1). Cultured macrophages were used to define consequences of tripartite motif containing 8 (TRIM8) knockdown on IFN-γ signalling.Results: Bulk RNA-seq of SJIA monocytes revealed marked transcriptional changes in patients with elevated ferritin levels. We identified substantial overlap with multiple polarisation states but little evidence of IFN-induced signature. Interestingly, among the most highly upregulated genes was TRIM8, a positive regulator of IFN-γ signalling. In contrast to PBMC from SJIA patients without MAS, scRNA-seq of BMM from a patient with SJIA and MAS identified distinct subpopulations of BMM with altered transcriptomes, including upregulated IFN-γ response pathways. These BMM also showed significantly increased expression of TRIM8. In vitro knockdown of TRIM8 in macrophages significantly reduced IFN-γ responsiveness.Conclusions: Macrophages with an 'IFN-γ response' phenotype and TRIM8 overexpression were expanded in the bone marrow from an MAS patient. TRIM8 is also upregulated in SJIA monocytes, and augments macrophage IFN-γ response in vitro, providing both a candidate molecular mechanism and potential therapeutic target for monocyte hyper-responsiveness to IFNγ in cytokine storms including MAS. [ABSTRACT FROM AUTHOR]

The impact of the COVID‐19 pandemic on training and Shared Resource Laboratory (SRL) operations such as staffing, facility access, and social distancing, has affected facilities around the globe to different degrees based on restrictions set by various geographical and institutional settings. With these restrictions come unique challenges regarding user and staff training and education, for both theory and practice. Most notably, limitations in facility access, occupancy, staffing availability, network restrictions and trainee engagement call for innovative solutions for training when traditional in‐person options are not feasible. Through the use of remote access tools and prerecorded educational and training materials, SRLs are able to overcome these obstacles. Here, we focus on readily available technologies and general guidelines that SRLs in different environments can use for remote cytometry training and education, while highlighting key obstacles that still remain. Although SRLs may face initial struggles in transitioning trainings to a virtual format, remote technologies provide unique opportunities to advance current training programs. © 2020 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]

Biosafety has always been an important aspect of daily work in any research institution, particularly for cytometry Shared Resources Laboratories (SRLs). SRLs are common‐use spaces that facilitate the sharing of knowledge, expertise, and ideas. This sharing inescapably involves contact and interaction of all those within this working environment on a daily basis. The current pandemic caused by SARS‐CoV‐2 has prompted the re‐evaluation of many policies governing the operations of SRLs. Here we identify and review the unique challenges SRLs face in maintaining biosafety standards, highlighting the potential risks associated with not only cytometry instrumentation and samples, but also the people working with them. We propose possible solutions to safety issues raised by the COVID‐19 pandemic and provide tools for facilities to adapt to evolving guidelines and future challenges. [ABSTRACT FROM AUTHOR]

Objectives We used an unbiased proteomics approach to identify candidate urine biomarkers (CUBMs) predictive of LN chronicity and pursued their validation in a larger cohort. Methods In this cross-sectional pilot study, we selected urine collected at kidney biopsy from 20 children with varying levels of LN damage (discovery cohort) and performed proteomic analysis using isobaric tags for relative and absolute quantification (iTRAQ). We identified differentially excreted proteins based on degree of LN chronicity and sought to distinguish markers exhibiting different relative expression patterns using hierarchically clustered log10-normalized relative abundance data with linked and distinct functions by biological network analyses. For each CUBM, we performed specific ELISAs on urine from a validation cohort (n = 41) and analysis of variance to detect differences between LN chronicity, with LN activity adjustment. We evaluated for CUBM expression in LN biopsies with immunohistochemistry. Results iTRAQ detected 112 proteins in urine from the discovery cohort, 51 quantifiable in all replicates. Simple analysis of variance revealed four differentially expressed, chronicity-correlated proteins (P -values < 0.05). Further correlation and network analyses led to selection of seven CUBMs for LN chronicity. In the validation cohort, none of the CUBMs distinguished LN chronicity degree; however, urine SERPINA3 demonstrated a moderate positive correlation with LN histological activity. Immunohistochemistry further demonstrated SERPINA3 staining in proximal tubular epithelial and endothelial cells. Conclusion We identified SERPINA3, a known inhibitor of neutrophil cathepsin G and angiotensin II production, as a potential urine biomarker to help quantify LN activity. [ABSTRACT FROM AUTHOR]

Abstract: Systemic juvenile idiopathic arthritis (SJIA) is a severe childhood arthropathy with features of autoinflammation. Monocytes and macrophages in SJIA have a complex phenotype with both pro‐ and anti‐inflammatory properties that combine features of several well characterized in vitro conditions used to activate macrophages. An important anti‐inflammatory phenotype is expression of CD163, a scavenger receptor that sequesters toxic pro‐inflammatory complexes that is highly expressed in both active SJIA and macrophage activation syndrome (MAS). CD163 is most strongly up‐regulated by IL‐10 (M(IL‐10)), and not by other conditions that reflect features seen in SJIA monocytes such as M(LPS+IC). MicroRNA plays key roles in integrating cellular signals such as those in macrophage polarization, and as such we hypothesize microRNAs regulate macrophage functional responses in SJIA including CD163 expression. We find that 2 microRNAs previously found to be elevated in active SJIA, miR‐125a‐5p and miR‐181c, significantly reduced macrophage CD163 expression through 2 distinct mechanisms. Neither microRNA was elevated in M(IL‐10) with robust CD163 expression, but were instead induced in M(LPS+IC) where they restricted CD163 mRNA expression. Mir‐181 species directly targeted CD163 mRNA for degradation. In contrast, miR‐125a‐5p functions indirectly, as transcriptome analysis of miR‐125a‐5p overexpression identified “cytokine‐cytokine receptor interactions” as the most significantly repressed gene pathway, including decreased IL10RA, required for IL‐10‐mediated CD163 expression. Finally, overexpression of miR‐181c inhibited CD163 anti‐inflammatory responses to hemoglobin or high mobility group box 1 (HMGB1) complexes. Together, these data show that microRNA utilizes multiple mechanisms to integrate well‐characterized polarization phenotypes and regulate macrophage functional properties seen in SJIA. [ABSTRACT FROM AUTHOR]

Objective Systemic juvenile idiopathic arthritis (JIA) is an inflammatory disease of childhood in which cells of the monomyelocytoid lineage are thought to be key effector cells. Monocytes from patients with systemic JIA have a distinct phenotype, with features of both M1 and M2 alternative activation. MicroRNAs are critical regulators of monocyte polarization and function, but cellular microRNAs in systemic JIA have not been examined systematically. Methods MicroRNA TaqMan arrays were used to determine the expression profiles of monocytes from children with systemic JIA. Expression of microRNA-125a-5p (miR-125a-5p) and its contribution to monocyte polarization were examined using in vitro-polarized THP-1 cells and primary human monocytes. Results A total of 110 microRNAs were found to be differentially expressed in monocytes from patients with active systemic JIA, including molecules implicated in rheumatoid arthritis pathogenesis, cytokine production, and monocyte polarization. MicroRNA-125a-5p was identified as being highly up-regulated in monocytes from children with active systemic JIA, as compared to those from children with clinically inactive JIA or those with active polyarticular JIA, and correlated with systemic features of the disease. In vitro, monocyte miR125a-5p expression was increased after polarization under M2b or M2c conditions. Inhibition of miR-125a-5p showed that this microRNA contributed to full polarization of M2b regulatory macrophages. In contrast, miR-125a-5p overexpression enhanced M2b polarization and altered other polarized populations, including increasing the production of M2 markers. Indeed, in vitro overexpression of this microRNA altered the macrophage phenotype toward that observed in systemic JIA. Conclusion Children with active systemic JIA have profound alterations in the expression of microRNAs that are implicated in monocyte function and polarization. One of these microRNAs, miR-125a-5p, is also a regulator of immunoregulatory M2b macrophages. [ABSTRACT FROM AUTHOR]

Objective IgG antibodies protect by aggregating pathogens and activating complement and stimulatory Fcγ receptors (FcγR). Although IgG1 accounts for a large percentage of murine serum antibodies, it poorly activates complement, binds more avidly to inhibitory FcγRIIb than to stimulatory FcγRIII, and has a relatively low aggregating ability. We previously demonstrated that IgG1 protects against complement- and FcγR-independent renal disease by inhibiting immune complex obstruction of glomerular capillaries. The purpose of this study was to determine whether IgG1 also protects against the complement- and FcγR-dependent disorder, collagen-induced arthritis (CIA). Methods CIA was induced by injecting mice with type II collagen (CII) (active model) or with IgG2a and IgG2b anti-CII monoclonal antibodies (ArthritoMab) (passive model). Arthritis severity was assessed, and CII-specific IgG was titered. Results Cγ1-deficient C57BL/6 mice lack IgG1 (IgG1−/−); in these mice, arthritis developed at a higher frequency and was more severe compared with IgG1+/+ mice in the active model. Disease was FcγRIII- and C3-dependent in both the IgG+/+ and IgG−/− mouse strains and was not influenced by interleukin-4 receptor α in either strain. CII-specific IgG2a/c titers were considerably higher in IgG1−/− than in IgG1+/+ mice and correlated with CIA incidence and severity. IgG1+/+ mice that developed CIA had higher CII-specific IgG1 and IgG2a/c levels than did those without CIA. CII-inoculated BALB/c IgG1+/+ and IgG1−/− mice had much lower CII-specific IgG2a/c titers than did C57BL/6 mice and failed to develop CIA but developed passive CIA when given ArthritoMab. Conclusion The absence of a functional Cγ1 gene indirectly promotes the development of CIA, likely through increased production of IgG2a/c, an isotype that strongly activates complement and stimulatory FcγR. [ABSTRACT FROM AUTHOR]

Rheumatoid arthritis is a chronic inflammatory disease affecting approximately 1% of the population and is characterized by cartilage and bone destruction ultimately leading to loss of joint function. Early detection and intervention of disease provides the best hope for successful treatment and preservation of joint mobility and function. Reliable and non-invasive techniques that accurately measure arthritic disease onset and progression are lacking. We recently developed a novel agent, SapC-DOPS, which is composed of the membrane-associated lysosomal protein saposin C (SapC) incorporated into 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) lipid nanovesicles. SapC-DOPS has a high fusogenic affinity for phosphatidylserine-enriched microdomains on surfaces of target cell membranes. Incorporation of a far-red fluorophore, CellVue Maroon (CVM), into the nanovesicles allows for in vivo non-invasive visualization of the agent in targeted tissue. Given that phosphatidylserine is present only on the inner leaflet of healthy plasma membranes but is "flipped" to the outer leaflet upon cell damage, we hypothesized that SapC-DOPS would target tissue damage associated with inflammatory arthritis due to local surface-exposure of phosphatidylserine. Optical imaging with SapC-DOPS-CVM in two distinct models of arthritis, serum-transfer arthritis (e.g., K/BxN) and collagen-induced arthritis (CIA) revealed robust SapC-DOPS-CVM specific localization to arthritic paws and joints in live animals. Importantly, intensity of localized fluorescent signal correlated with macroscopic arthritic disease severity and increased with disease progression. Flow cytometry of cells extracted from arthritic joints demonstrated that SapC-DOPS-CVM localized to an average of 7-8% of total joint cells and primarily to CD11b+Gr-1+ cells. Results from the current studies strongly support the application of SapC-DOPS-CVM for advanced clinical and research applications including: detecting early arthritis onset, assessing disease progression real-time in live subjects, and providing novel information regarding cell types that may mediate arthritis progression within joints. [ABSTRACT FROM AUTHOR]

BackgroundMethodsResultsConclusion\nKEY POINTSUveitis is an inflammatory ocular disease secondary to disruption of the retinal pigmented epithelium (RPE) and blood retinal barrier (BRB). Known clinical factors do not accurately predict uveitis risk in Juvenile Idiopathic Arthritis (JIA). Tear fluid is easily obtained for biomarker study. We aim to identify tear-based markers associated with the presence of uveitis in children with JIA.In a cross-sectional comparative cohort study, tears were collected by Schirmer strips from children with oligoarticular JIA-associated uveitis (JIA-U) and JIA without uveitis (JIA-no-U). A tandem isotope tagging (iTRAQ and TMT) strategy was used for relative quantitation via nanoLC-MS/MS to quantify proteins in the affected eye. Log transformed relative protein abundance of protein levels was compared between groups using Wilcoxon exact test. We explored the influence of arthritis activity and topical corticosteroids (CS) use on protein levels. STRING analysis was performed.Tear samples of 14 JIA-U and 14 JIA-no-U patients were analyzed. Thirteen proteins were differentially expressed between both groups. Stratified analysis based on arthritis activity (inactive arthritis) and topical CS (off CS) showed that alpha-2-macroglobulin (p = 0.012), apolipoprotein A1 (p = 0.036), S100A9 (p = 0.05), haptoglobin (p = 0.066), and transthyretin (p = 0.066) consistently differentiated between both groups. On STRING analysis, these proteins were associated with the RPE, BRB, and inflammation.Importantly, we identified proteins involved in the RPE, BRB, and immune response that were differentially abundant in the tears of children with JIA-U compared to JIA-no-U, regardless of arthritis activity or topical CS. Candidate tear-based biomarkers may represent a non-invasive means to detect uveitis.Question: Is it possible to identify tear-based biomarkers able to identify patients with uveitis in children with Juvenile Idiopathic Arthritis (JIA)?Findings: We identified proteins involved in the immune response and in the retinal barrier that were differentially abundant in the tears of children with JIA-Uveitis compared to JIA-no-Uveitis.Meaning: Tears may be a suitable sample to identify children with JIA with and without uveitis in a non-invasive and objective way. [ABSTRACT FROM AUTHOR]

CD163 facilitates regulation and resolution of inflammation and removal of free hemoglobin and is highly expressed in myeloid cells from patients with inflammatory disorders, such as systemic juvenile idiopathic arthritis (SJIA) and macrophage activation syndrome (MAS). Our recent studies indicate that regulation of CD163 mRNA expression is a key functional property of polarized monocytes and macrophages and is mediated at the transcriptional and posttranscriptional level, including via microRNAs. The goal of the current study is to develop a multiparameter flow cytometry panel incorporating detection of CD163 mRNAfor polarized monocyte and macrophage populations in disorders such as SJIA and MAS. THP-1 cells and CD14+ human monocytes were stained using fluorochrome-conjugated Abs to myeloid surface markers, along with CD163 mRNA. Staining for mRNA could reliably detect CD163 expression while simultaneously detecting different macrophage populations using Abs targeting CD14, CD64, CD80, CD163, and CD209. This approach was found to be highly sensitive for increased mRNA expression when macrophages were polarized with IL-10 [M(IL-10)], with a strong signal over a broad range of IL-10 concentrations, and showed distinct kinetics of CD163 mRNA and protein induction upon IL-10 stimulation. Finally, this panel demonstrated clear changes in polarization markers in unstimulated monocytes from patients with SJIA and MAS, including upregulated CD163 mRNA and increased CD64 expression. This approach represents a robust and sensitive system for RNA flow cytometry, useful for studying CD163 expression as part of a multimarker panel for human monocytes and macrophages, with broad applicability to the pathogenesis of hyperinflammatory diseases. [ABSTRACT FROM AUTHOR]

Saposin C-dioleoylphosphatidylserine (SapC-DOPS) nanovesicles are a nanotherapeutic which effectively target and destroy cancer cells. Here, we explore the systemic use of SapC-DOPS in several models of brain cancer, including glioblastoma multiforme (GBM), and the molecular mechanism behind its tumor-selective targeting specificity. Using two validated spontaneous brain tumor models, we demonstrate the ability of SapC-DOPS to selectively and effectively cross the blood-brain tumor barrier (BBTB) to target brain tumors in vivo and reveal the targeting to be contingent on the exposure of the anionic phospholipid phosphatidylserine (PtdSer). Increased cell surface expression of PtdSer levels was found to correlate with SapC-DOPS-induced killing efficacy, and tumor targeting in vivo was inhibited by blocking PtdSer exposed on cells. Apart from cancer cell killing, SapC-DOPS also exerted a strong antiangiogenic activity in vitro and in vivo. Interestingly, unlike traditional chemotherapy, hypoxic cells were sensitized to SapC-DOPS-mediated killing. This study emphasizes the importance of PtdSer exposure for SapC-DOPS targeting and supports the further development of SapC-DOPS as a novel antitumor and antiangiogenic agent for brain tumors. [ABSTRACT FROM AUTHOR]

Abstract: CD8+ T lymphocytes recognize tumor and viral antigens bound to class I major histocompatibility complexes (MHC). Tumors and viruses may evade detection by preventing antigen presentation. The present study was designed to determine whether a soluble divalent fusion protein, containing the extracellular domains of a class I MHC molecule fused to β2-microglobulin and the constant domains of IgG1, could induce an immune response in vivo. Administration to mice of the fusion protein loaded with a tumor peptide induced peptide-specific T cell activation and retarded tumor growth. Administration of the fusion protein loaded with a glycoprotein B (gB) peptide derived from herpes simplex virus type 1 (HSV-1) induced gB-specific cytotoxic T lymphocytes and protected mice from a lethal HSV-1 challenge. These data suggest that antigen-loaded MHC/IgG fusion proteins may enhance T cell immunity in conditions where antigen presentation is altered. [Copyright &y& Elsevier]

Objective: To assess changes in gene expression following tofacitinib treatment and investigate transcription patterns as potential predictors of treatment response in patients with active juvenile idiopathic arthritis (JIA)., Methods: Whole-blood samples were collected from patients with JIA at baseline and after 18 weeks of open-label tofacitinib treatment. Patients who achieved a JIA-American College of Rheumatology (ACR) response of 70% or above at week 18 were classified as treatment responders (TRs), whereas those with at most a JIA-ACR30 were classified as poor responders (PRs). Differential gene expression and gene ontology overrepresentation analyses were performed to compare RNA expression between week 18 and baseline samples, as well as between PR and TR samples at baseline., Results: Samples from 67 patients at baseline and 60 patients at week 18 were analyzed. After 18 weeks of tofacitinib treatment across all patients with JIA, 883 genes showed significant differential expression (week 18 to baseline). The most strongly down-regulated genes were overrepresented within interleukin-7 (IL-7) and type I and type II interferon pathways, whereas up-regulated genes were enriched in ontologies related to neuronal cell processes and cell signaling. Comparing PRs and TRs at baseline, 663 genes showed differential expression. Up-regulated genes were overrepresented within ontologies including activation of MAPK activity (P = 9.40 × 10 -5 ), myeloid cell development (P = 8.13 × 10 -5 ), activation of GTPase activity (P = 0.00015), and organelle transport along microtubules (P = 0.00021)., Conclusion: Tofacitinib treatment in JIA down-regulated genes in interferon and IL-7 signaling pathways regardless of effectiveness. Furthermore, baseline up-regulation of MAPK signaling may predict poor response to tofacitinib treatment in JIA., (© 2024 American College of Rheumatology.)