What to Expect When Systemic Treatment in Juvenile Idiopathic Arthritis Is Withdrawn?

OBJECTIVE: The goal of juvenile idiopathic arthritis (JIA) treatment is to maintain clinical remission. It is also important to reduce drug exposure, whenever possible, in order to avoid or decrease potential side effects. We aimed to analyze remission survival after systemic treatment withdrawal and to determine which factors can influence it. METHODS: We conducted a multicenter, observational, longitudinal study. All patients included had a diagnosis of JIA. We analyzed remission survival using Kaplan-Meier curves according to the systemic treatment received (methotrexate [MTX] alone or in combination with biologic disease-modifying antirheumatic drugs [bDMARDs]) and JIA subgroups (oligoarticular and polyarticular course, juvenile spondyloarthritis, and systemic JIA). In addition, risk factors were examined using multivariate analysis. RESULTS: We included 404 patients with JIA; 370 of them (92%) had received systemic treatment at some point and half of them (185 patients) had withdrawn on at least 1 occasion. There were 110 patients who flared (59%) with a median time of 2.3 years. There were no differences in remission survival between JIA subcategories. Twenty-nine percent of patients with JIA who received MTX and bDMARDs, in which MTX alone was withdrawn, flared; median time to flare of 6.3 years. However, if only the bDMARD was withdrawn, flares occurred 57% of the time; median time to flare of 1.1 years. CONCLUSION: Flares are frequent when systemic treatment is withdrawn, and uveitis or joint injections could be related risk factors. In MTX and biologic-naïve patients, the frequency of flares occurred in more than half of patients, although they were less frequent when clinical remission lasted for > 1 year.

TLR7 gain-of-function genetic variation causes human lupus.

Although circumstantial evidence supports enhanced Toll-like receptor 7 (TLR7) signalling as a mechanism of human systemic autoimmune disease1-7, evidence of lupus-causing TLR7 gene variants is lacking. Here we describe human systemic lupus erythematosus caused by a TLR7 gain-of-function variant. TLR7 is a sensor of viral RNA8,9 and binds to guanosine10-12. We identified a de novo, previously undescribed missense TLR7Y264H variant in a child with severe lupus and additional variants in other patients with lupus. The TLR7Y264H variant selectively increased sensing of guanosine and 2',3'-cGMP10-12, and was sufficient to cause lupus when introduced into mice. We show that enhanced TLR7 signalling drives aberrant survival of B cell receptor (BCR)-activated B cells, and in a cell-intrinsic manner, accumulation of CD11c+ age-associated B cells and germinal centre B cells. Follicular and extrafollicular helper T cells were also increased but these phenotypes were cell-extrinsic. Deficiency of MyD88 (an adaptor protein downstream of TLR7) rescued autoimmunity, aberrant B cell survival, and all cellular and serological phenotypes. Despite prominent spontaneous germinal-centre formation in Tlr7Y264H mice, autoimmunity was not ameliorated by germinal-centre deficiency, suggesting an extrafollicular origin of pathogenic B cells. We establish the importance of TLR7 and guanosine-containing self-ligands for human lupus pathogenesis, which paves the way for therapeutic TLR7 or MyD88 inhibition.

Artritis séptica como forma de inicio de una piomiositis / Pyomyositis presenting as septic arthritis

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Can ultrasound-detected subclinical synovitis be an indicator of flare recurrence in juvenile idiopathic arthritis remission patients on tapered TNFi?

OBJECTIVES: Subclinical synovitis is often detected by musculoskeletal ultrasound (MSUS) in juvenile idiopathic arthritis (JIA) patients in clinical remission. The main objective of this prospective, observational, longitudinal, multicentre study was to evaluate the predictive value of MSUS-detected subclinical synovitis in relation to flares at 12 months following TNFi tapering in a JIA population in stable clinical remission. METHODS: We included 56 JIA patients in stable remission undergoing TNFi therapy tapered at baseline and in some cases at 6 months. We performed baseline and 6-month MSUS assessment on B-mode (BM) and power Doppler (PD) mode of 22 joints and 8 tendons. RESULTS: Eighteen patients (32.1%) experienced a flare during the 12-month study period. BM synovitis was frequent (83.9%) but PD synovitis was scarcely found (8.9%). There were no significant differences in MSUS findings between patients who experienced a flare and those who remained in remission. Only 5 patients had positive for PD synovitis, in joints with BM synovitis grades 2 or 3, and none experienced a flare. Concomitant methotrexate (MTX) was more frequent in patients who were successfully tapered (71.1% vs. 27.8%; p=0.002) and patients older than 12 experienced a greater number of flares and earlier onset. CONCLUSIONS: Subclinical synovitis, as detected by MSUS, proved not to be a predictor of flares. Those patients on a TNFi-tapered concomitant methotrexate regimen experienced the fewest flares although flare risk increased with age.