Joint-specific memory, resident memory T cells and the rolling window of opportunity in arthritis.

In rheumatoid arthritis, juvenile idiopathic arthritis and other forms of inflammatory arthritis, the immune system targets certain joints but not others. The pattern of joints affected varies by disease and by individual, with flares most commonly involving joints that were previously inflamed. This phenomenon, termed joint-specific memory, is difficult to explain by systemic immunity alone. Mechanisms of joint-specific memory include the involvement of synovial resident memory T cells that remain in the joint during remission and initiate localized disease recurrence. In addition, arthritis-induced durable changes in synovial fibroblasts and macrophages can amplify inflammation in a site-specific manner. Together with ongoing systemic processes that promote extension of arthritis to new joints, these local factors set the stage for a stepwise progression in disease severity, a paradigm for arthritis chronicity that we term the joint accumulation model. Although durable drug-free remission through early treatment remains elusive for most forms of arthritis, the joint accumulation paradigm defines new therapeutic targets, emphasizes the importance of sustained treatment to prevent disease extension to new joints, and identifies a rolling window of opportunity for altering the natural history of arthritis that extends well beyond the initiation phase of disease.

Recent advances and evolving concepts in Still's disease.

Still's disease is a rare inflammatory syndrome that encompasses systemic juvenile idiopathic arthritis and adult-onset Still's disease, both of which can exhibit life-threatening complications, including macrophage activation syndrome (MAS), a secondary form of haemophagocytic lymphohistiocytosis. Genetic insights into Still's disease involve both HLA and non-HLA susceptibility genes, suggesting the involvement of adaptive immune cell-mediated immunity. At the same time, phenotypic evidence indicates the involvement of autoinflammatory processes. Evidence also implicates the type I interferon signature, mechanistic target of rapamycin complex 1 signalling and ferritin in the pathogenesis of Still's disease and MAS. Pathological entities associated with Still's disease include lung disease that could be associated with biologic DMARDs and with the occurrence of MAS. Historically, monophasic, recurrent and persistent Still's disease courses were recognized. Newer proposals of alternative Still's disease clusters could enable better dissection of clinical heterogeneity on the basis of immune cell profiles that could represent diverse endotypes or phases of disease activity. Therapeutically, data on IL-1 and IL-6 antagonism and Janus kinase inhibition suggest the importance of early administration in Still's disease. Furthermore, there is evidence that patients who develop MAS can be treated with IFNγ antagonism. Despite these developments, unmet needs remain that can form the basis for the design of future studies leading to improvement of disease management.

The 4th NextGen Therapies for SJIA and MAS: part 1 the elephant in the room: diagnostic/classification criteria for systemic juvenile idiopathic arthritis and adult-onset still's disease.

Currently, the criteria used to classify patients with SJIA are different from those used for AOSD. However, it has been recognized that the existing terms are too narrow, subdividing the Still's population unnecessarily between pediatric-onset and adult-onset disease and excluding an appreciable group of children in whom overt arthritis is delayed or absent. Government regulators and insurers rely upon the guidance of subject experts to provide disease definitions, and when these definitions are flawed, to provide new and better ones. The classification session at the NextGen 2022 conference helped to serve this purpose, establishing the need for a revised definitional system that transcends the fault lines that remain in existing definitions.

Longitudinal program evaluation of an inter-institutional mentorship network for pediatric rheumatology using a quality improvement framework.

BACKGROUND: The American College of Rheumatology (ACR)/Childhood Arthritis and Rheumatology Research Alliance (CARRA) Mentoring Interest Group (AMIGO) is an inter-institutional mentorship program launched to target mentorship gaps within pediatric rheumatology. Initial program evaluation indicated increased mentorship access. Given the small size of the pediatric rheumatology workforce, maintaining a consistent supply of mentors was a potential threat to the longevity of the network. Our aims were to: (i) describe the sustainability of AMIGO over the period 2011-2018, (ii) highlight ongoing benefits to participants, and (iii) describe challenges in the maintenance of a mentorship network. METHODS: A mixed-methods approach centered on a quality improvement framework was used to report on process and outcomes measures associated with AMIGO annual cycles. RESULTS: US and Canada Pediatric rheumatology workforce surveys identified 504 possible participants during the time period. As of fall 2018, 331 unique individuals had participated in AMIGO as a mentee, mentor or both for a program response rate of 66% (331/504). Survey of mentees indicated high satisfaction with impact on general career development, research/scholarship and work-life balance. Mentors indicated increased sense of connection to the community and satisfaction with helping mentees despite limited perceived benefit to their academic portfolios. Based on AMIGO's success, a counterpart program for adult rheumatology, Creating Adult Rheumatology Mentorship in Academia (CARMA), was launched in 2018. CONCLUSIONS: Despite the challenges of a limited workforce, AMIGO continues to provide consistent access to mentorship opportunities for the pediatric rheumatology community. This experience can inform approaches to mentorship gaps in other academic subspecialties.

High-throughput identification of functional regulatory SNPs in systemic lupus erythematosus.

Genome-wide association studies implicate multiple loci in risk for systemic lupus erythematosus (SLE), but few contain exonic variants, rendering systematic identification of non-coding variants essential to decoding SLE genetics. We utilized SNP-seq and bioinformatic enrichment to interrogate 2180 single-nucleotide polymorphisms (SNPs) from 87 SLE risk loci for potential binding of transcription factors and related proteins from B cells. 52 SNPs that passed initial screening were tested by electrophoretic mobility shift and luciferase reporter assays. To validate the approach, we studied rs2297550 in detail, finding that the risk allele enhanced binding to the transcription factor Ikaros (encoded by IKZF1), thereby modulating expression of IKBKE. Correspondingly, primary cells from genotyped healthy donors bearing the risk allele expressed higher levels of the interferon / NF-κB regulator IKKε. Together, these findings define a set of likely functional non-coding lupus risk variants and identify a regulatory pathway involving rs2297550, Ikaros, and IKKε implicated by human genetics in risk for SLE.

Real-world application of the pediatric Glucocorticoid Toxicity Index in childhood-onset lupus.

OBJECTIVES: The pediatric Glucocorticoid Toxicity Index (pGTI) is a new, pediatric-specific tool to quantify glucocorticoid (GC)-related morbidity in children. We evaluated the feasibility and construct validity of retrospective pGTI scoring in patients with pediatric-onset systemic lupus erythematosus (pSLE) and identified risk factors for cumulative toxicity. METHODS: We conducted a retrospective cohort study of patients with pSLE treated with GCs at two pediatric centers (1999-2023). GC exposure was estimated using interval-averaged oral prednisone-equivalent dose and cumulative prednisone-equivalent dose. We scored change in GC toxicity every 6 months (±2) using a modified pGTI including 7 of 10 domains. We calculated the Cumulative Worsening Score (CWS), a continuous summation of toxicity accrued. Mixed effects linear regression was used to identify factors associated with CWS. RESULTS: There were 126 patients with pSLE, including 88 with nephritis, with a median of 6 visits/patient. Nearly half (47 %) experienced toxicity in the Blood Pressure domain. Other common toxicities were mood disturbance (25 %), followed by increased body mass index (BMI), striae, and sleep disturbance (21 % each). Decreased growth velocity was observed in 18 %. There was modest correlation between cumulative GC dose and CWS (rho 0.3; p < 0.01). Greater cumulative toxicity was associated with younger age, elevated BMI, and rituximab use at the time of GC initiation, albeit indications for the latter were not captured. CONCLUSIONS: Patients with pSLE experience a high burden of GC toxicity, particularly related to blood pressure, BMI, sleep, and growth. Standardized, pediatric-specific GC toxicity assessment is feasible in real-world settings and can facilitate evaluation of strategies to reduce morbidity in children requiring chronic GC treatment.

Non-coding autoimmune risk variant defines role for ICOS in T peripheral helper cell development.

Fine-mapping and functional studies implicate rs117701653, a non-coding single nucleotide polymorphism in the CD28/CTLA4/ICOS locus, as a risk variant for rheumatoid arthritis and type 1 diabetes. Here, using DNA pulldown, mass spectrometry, genome editing and eQTL analysis, we establish that the disease-associated risk allele is functional, reducing affinity for the inhibitory chromosomal regulator SMCHD1 to enhance expression of inducible T-cell costimulator (ICOS) in memory CD4+ T cells from healthy donors. Higher ICOS expression is paralleled by an increase in circulating T peripheral helper (Tph) cells and, in rheumatoid arthritis patients, of blood and joint fluid Tph cells as well as circulating plasmablasts. Correspondingly, ICOS ligation and carriage of the rs117701653 risk allele accelerate T cell differentiation into CXCR5-PD-1high Tph cells producing IL-21 and CXCL13. Thus, mechanistic dissection of a functional non-coding variant in human autoimmunity discloses a previously undefined pathway through which ICOS regulates Tph development and abundance.

Classification Criteria for Axial Disease in Youth with Juvenile Spondyloarthritis.

OBJECTIVES: To develop and validate classification criteria for axial disease in youth with juvenile spondyloarthritis (SpA; AxJSpA). METHODS: This international initiative consisted of four phases: 1) Item generation; 2) Item reduction; 3) Criteria development; and 4) Validation of the AxJSpA criteria by an independent team of experts in an internationally representative Validation cohort. RESULTS: These criteria are intended to be used on youth with a physician diagnosis of juvenile SpA and for whom axial disease is suspected. Item generation consisted of a systematic literature review and a free-listing exercise using input from international physicians and collectively resulted in 108 items. After the item reduction exercise and expert panel input, 37 items remained for further consideration. The final AxJSpA criteria domains included: imaging: active inflammation, imaging: structural lesions, pain chronicity, pain pattern, pain location, stiffness, and genetics. The most heavily weighted domains were active inflammation and structural lesions on imaging. Imaging typical of sacroiliitis was deemed necessary, but not sufficient, to classify a youth with AxJSpA. The threshold for classification of AxJSpA was a score of ≥55 (out of 100). When tested in the validation data set, the final criteria had a specificity of 97.5% (95% CI: 91.4-99.7), sensitivity of 64.3% (95% CI: 54.9-73.1) and Area Under the Receiver Operating Characteristic (AUROC) curve of 0.81 (95% CI: 0.76-0.86). CONCLUSIONS: The new AxJSpA classification criteria require an entry criterion, physician diagnosis of juvenile SpA, and include seven weighted domains. The AxJSpA classification criteria are validated and designed to identify participants for research studies.

Longitudinal program evaluation of an inter-institutional mentorship network for pediatric rheumatology using a quality improvement framework.

Background: The American College of Rheumatology (ACR)/Childhood Arthritis and Rheumatology Research Alliance (CARRA) Mentoring Interest Group (AMIGO) is an inter-institutional mentorship program launched to target mentorship gaps within pediatric rheumatology. Initial program evaluation indicated increased mentorship access. Given the small size of the pediatric rheumatology workforce, maintaining a consistent supply of mentors was a potential threat to the longevity of the network. Our aims were to: (i) describe the sustainability of AMIGO over the period 2011-2018, (ii) highlight ongoing benefits to participants, and (iii) describe challenges in the maintenance of a mentorship network. Methods: A mixed-methods approach centered on a quality improvement framework was used to report on process and outcomes measures associated with AMIGO annual cycles. Results: US and Canada Pediatric rheumatology workforce surveys identified 504 possible participants during the time period. As of fall 2018, 331 unique individuals had participated in AMIGO as a mentee, mentor or both for a program response rate of 66% (331/504). Survey of mentees indicated high satisfaction with impact on general career development, research/scholarship and work-life balance. Mentors indicated increased sense of connection to the community and satisfaction with helping mentees despite minimal perceived benefit to their academic portfolios. Based on AMIGO's success, a counterpart program, Creating Adult Rheumatology Mentorship in Academia (CARMA), was launched in 2018. Conclusions: Despite the challenges of a limited workforce, AMIGO continues to provide consistent access to mentorship opportunities for the pediatric rheumatology community. This experience can inform approaches to mentorship gaps in other academic subspecialties.