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Introduction: Systemic juvenile idiopathic arthritis (sJIA), a multifaceted autoinflammatory disorder, can be complicated by life-threatening conditions such as macrophage activation syndrome (MAS) and interstitial lung disease (ILD). The management of these conditions presents a therapeutic challenge, underscoring the need for innovative treatment approaches., Objectives: to report the possible role of MAS825, a bispecific anti-IL1β and IL-18 monoclonal antibody, in the treatment of multi-drug-resistant sJIA., Methods: We report two patients affected by sJIA with severe and refractory MAS and high serum IL-18 levels, responding to dual blockade of IL-1β and IL-18., Results: The first patient is a 20-year-old man, presenting a severe MAS complicated by thrombotic microangiopathy, following SARS-CoV-2 infection. He was treated with MAS825, with quick improvement. Eighteen months later, the patient is still undergoing biweekly treatment with MAS825, associated with MTX, ciclosporin and low-dose glucocorticoids, maintaining good control over the systemic features of the disease.The second patient, a 10-year-old girl, presented a severe MAS case, complicated by posterior reversible encephalopathy syndrome (PRES), following an otomastoiditis. The MAS was not fully controlled despite treatment with IV high-dose glucocorticoids, anakinra and ciclosporin. She began biweekly MAS825, which led to a prompt amelioration of MAS parameters. After 10 months, the patient continues to receive MAS825 and is in complete remission., Conclusion: In light of the pivotal role of IL-1β and IL-18 in sJIA, MAS and ILD, MAS825 might represent a possible valid and safe option in the treatment of drug-resistant sJIA, especially in the presence of high serum IL-18 levels., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Photosynthesis occurs in thylakoids, a highly specialized membrane system. In the cyanobacterium Synechocystis sp PCC 6803 (hereafter Synechocystis 6803), the thylakoids are arranged parallel to the plasma membrane and occasionally converge toward it to form biogenesis centers. The initial steps in PSII assembly are thought to take place in these regions, which contain a membrane subcompartment harboring the early assembly factor PratA and are referred to as PratA-defined membranes (PDMs). Loss of CurT, the Synechocystis 6803 homolog of Arabidopsis thaliana grana-shaping proteins of the CURVATURE THYLAKOID1 family, results in disrupted thylakoid organization and the absence of biogenesis centers. As a consequence, PSII is less efficiently assembled and accumulates to only 50% of wild-type levels. CurT induces membrane curvature in vitro and is distributed all over the thylakoids, with local concentrations at biogenesis centers. There it forms a sophisticated tubular network at the cell periphery, as revealed by live-cell imaging. CurT is part of several high molecular mass complexes, and Blue Native/SDS-PAGE and isoelectric focusing demonstrated that different isoforms associate with PDMs and thylakoids. Moreover, CurT deficiency enhances sensitivity to osmotic stress, adding a level of complexity to CurT function. We propose that CurT is crucial for the differentiation of membrane architecture, including the formation of PSII-related biogenesis centers, in Synechocystis 6803., (© 2016 American Society of Plant Biologists. All rights reserved.)

Chloroplasts of land plants characteristically contain grana, cylindrical stacks of thylakoid membranes. A granum consists of a core of appressed membranes, two stroma-exposed end membranes, and margins, which connect pairs of grana membranes at their lumenal sides. Multiple forces contribute to grana stacking, but it is not known how the extreme curvature at margins is generated and maintained. We report the identification of the CURVATURE THYLAKOID1 (CURT1) protein family, conserved in plants and cyanobacteria. The four Arabidopsis thaliana CURT1 proteins (CURT1A, B, C, and D) oligomerize and are highly enriched at grana margins. Grana architecture is correlated with the CURT1 protein level, ranging from flat lobe-like thylakoids with considerably fewer grana margins in plants without CURT1 proteins to an increased number of membrane layers (and margins) in grana at the expense of grana diameter in overexpressors of CURT1A. The endogenous CURT1 protein in the cyanobacterium Synechocystis sp PCC6803 can be partially replaced by its Arabidopsis counterpart, indicating that the function of CURT1 proteins is evolutionary conserved. In vitro, Arabidopsis CURT1A proteins oligomerize and induce tubulation of liposomes, implying that CURT1 proteins suffice to induce membrane curvature. We therefore propose that CURT1 proteins modify thylakoid architecture by inducing membrane curvature at grana margins.

Background: Childhood-onset Crohn's disease (CD) might reflect a more severe form of disease. To test this hypothesis we analyzed the long-term natural history of CD in an adult cohort of patients with childhood-onset compared to adult-onset CD., Methods: We selected 206 childhood-onset CD patients among 2992 adult patients with a diagnosis of CD established before December 31, 2000. Disease characteristics were prospectively assessed during follow-up until December 2007 and compared to adult-onset CD patients matched 2 to 1 on gender, year of CD diagnosis, and disease location., Results: Compared to adult-onset CD, patients with childhood-onset CD were more likely to have a severe disease, with an increased year-by-year disease activity index (37% of patient-years in childhood-onset group versus 31% in the adult-onset group, P < 0.001). Immunosuppressant requirement was also increased with a 10-year cumulative risk of 54 +/- 3% in childhood-onset CD group versus 45 +/- 2%, in the adult-onset CD group (P < 0.001). Cumulative risks of stricturing and penetrating complications and surgical resections were not statistically different between groups. Accordingly, these events occurred at a younger age in the childhood-onset CD group. At the age of 30 years the actuarial risk of having undergone an extensive intestinal resection was 48 +/- 5% in the childhood-onset group versus 14 +/- 2% in the adult-onset group (P < 0.001)., Conclusions: Patients with childhood-onset CD exhibit a more active disease and require more immunosuppressive therapy. This feature is observed irrespective of the disease location, suggesting an intrinsic more severe phenotype.

Objective: To determine the capability and reliability of dynamic contrast-enhanced MRI (DCE-MRI) in the assessment of disease activity in juvenile idiopathic arthritis (JIA)., Methods: DCE-MRI of the clinically more affected wrist or hip joints was undertaken in 21 patients, coupled with standard clinical assessment and biochemical analysis. Synovial inflammation was assessed by computing the maximum level of synovial enhancement (ME), the maximum rate of enhancement (MV) and the rate of early enhancement (REE) from the enhancement curves generated from region of interest independently delineated by two readers in the area of the ME. Correlations between dynamic parameters and clinical measures of disease activity, and static MRI synovitis score were investigated., Results: In patients with wrist arthritis, REE correlated with the wrist swelling score (r(s) = 0.72), ESR (r(s) = 0.69), pain assessment scale (r(s) = 0.63) and childhood HAQ (r(s) = 0.60). In patients with hip arthritis, ME correlated with the hip limitation of motion (r(s) = 0.69). Static MRI synovitis score based on post-gadolinium enhancement correlated with MV (r(s) = 0.63) in patients with wrist arthritis and with ME (r = 0.68) in those with hip arthritis. The inter-reader agreement assessed by intra-class correlation coefficient (ICC) for ME, MV and REE (ICC = 0.98, 0.97 and 0.84, respectively) was excellent., Conclusions: DCE-MRI represents a promising method for the assessment of disease activity in JIA, especially in patients with wrist arthritis. As far as we know, this study is the first to demonstrate the feasibility, reliability and construct validity of DCE-MRI in JIA. These results should be confirmed in large-scale longitudinal studies in view of its further application in therapeutic decision making and in clinical trials.

Background: Infliximab (IFX) is efficacious in inducing remission in severe forms of pediatric Crohn's disease (CD). Adult studies indicate that IFX is also safe and well tolerated as maintenance therapy. The present study aimed to evaluate in a prospective manner the efficacy and safety of IFX as maintenance therapy of severe pediatric CD comparing scheduled and "on demand" treatment strategies., Methods: Forty children with CD (nonpenetrating, nonstricturing as well as penetrating forms, mean age: 13.9 +/- 2.2 years) with a severe flare-up (Harvey-Bradshaw Index [HBI] > or =5, erythrocyte sedimentation rate [ESR] >20 mm/h) despite well-conducted immunomodulator therapy (n = 36 azathioprine, n = 1 mercaptopurine, n = 3 methotrexate) combined with steroids were included in this randomized, multicenter, open-label study. Three IFX infusions (5 mg/kg) were administered at week (W)0/W2/W6. At W10, clinical remission (HBI <5) and steroid withdrawal were analyzed and IFX responders were randomized to maintenance therapy over 1 year: group A, scheduled every 2 months; group B, "on demand" on relapse., Results: In all, 34/40 children came into remission during IFX induction therapy (HBI: 6.7 +/- 2.5 (WO) vs. 1.1 +/- 1.5 (W10); P < 0.001). At the end of phase 2, 15/18 (83%) patients were in remission in group A compared to 8/13 (61%) children in group B (P < 0.01), with a mean HBI of 0.5 versus 3.2 points (group A versus B, P = 0.011). In group A, 3/13 (23.1%) children experienced a relapse compared to 11/12 (92%) children in group B. No severe adverse event occurred during this trial., Conclusions: IFX is well tolerated and safe as maintenance therapy for pediatric CD, with a clear advantage when used on a scheduled 2-month basis compared to an "on demand" basis.

Objective: To investigate the discrepancy between physician's and parent's global assessments of disease status and the factors explaining discordance in patients with juvenile idiopathic arthritis (JIA)., Methods: The mothers of 197 patients with JIA rated the child's overall well-being on a 10 cm visual analogue scale (VAS) and the attending physician rated the child's overall disease activity on a 10 cm VAS. A discordance score was calculated by subtracting the physician's global assessment from that of the parent's, leading to the definition of three patient groups: (1) no discordance, when physician's and parent's assessments were within 1 cm of each other; (2) negative discordance, when parent's assessment was underrated relative to the physician; and (3) positive discordance, when parent's assessment was over-rated relative to the physician. Negative and positive discordance was defined as 'marked' when the difference between the two assessments was greater than 3 cm., Results: No discordance was found in 40.6% of the patients. Negative discordance was found in 51.3% of the patients, with 34% showing marked discordance. Positive discordance was found in 8.1% of the patients, with 2% showing marked discordance. Significant differences between groups included a shorter disease duration among patients with a markedly positive discordance (P = 0.02) and a greater frequency of ongoing second-line drug therapy among patients with no discordance or with positive discordance (P = 0.008). Patients with no discordance or with marked positive discordance had a significantly lower joint counts (P = 0.02-0.004)., Conclusion: Parents and physicians often perceive the health status of children with JIA differently, with parents providing most frequently lower rating.

Infliximab, a monoclonal antibody against tumor necrosis factor-alpha, has been shown to be effective for the treatment of refractory Crohn's disease in adult patients, but experience in pediatrics is limited. This retrospective study included 88 children and adolescents, 39 girls and 49 boys, with a median age of 14 years (range 3.3-17.9). Infliximab was indicated for active disease (66%) and/or fistulas (42%) that were refractory to corticosteroids (70%), and/or other immunosuppressive (82%) agents, and/or parenteral nutrition (20%). Patients received 1 to 17 infusions (median 4) of 5 mg/kg (range 3.8-7.3) of infliximab during a median time period of 4 months (1-17 months). Infusion reaction was noted in 13 patients (15%), with a total of 16 reactions in 450 infusions (4%). At Day 90 after the first infusion of infliximab, symptoms improved in 49% of patients, whereas 29% of patients were in remission and 13% of patients relapsed. From Day 0 to Day 90, Harvey-Bradshaw score decreased from 7.5 to 2.8 (P < 0.001), C-reactive protein from 36 to 16 mg/L (P < 0.01), and 1-hour erythrocyte sedimentation rate from 35 to 17 mm (P < 0.01). Dosage of corticosteroids decreased from to 0.59 to 0.17 mg/kg/d (P < 0.001); 53% of patients could be weaned of corticosteroids and 92% of parenteral nutrition. Treatment with infliximab is well tolerated and effective in most children and adolescents with Crohn's disease that is refractory to conventional immunosuppressive therapy. Nevertheless, long-term efficacy remains to be shown, and further studies are urgently needed to precisely determine the best modality of continuing treatment.

Objective: To determine the level of agreement between parents and clinicians in rating dysfunction in children with juvenile idiopathic arthritis (JIA)., Methods: A parent of each patient completed the Italian version of the Childhood Health Assessment Questionnaire (CHAQ). Subsequently, an examiner assessed, in a specially equipped room, the child's performance of tasks as described by the CHAQ. Demographic and clinical variables were recorded for all patients., Results: Seventy consecutive JIA patients and their parents were included. The mean proxy-reported and observed CHAQ score was 0.64+/-0.53 and 0.47+/-0.62 respectively, the difference ranging from -1.75 to 1.5. There were 30 cases (43%) of agreement (difference < or =0.25 CHAQ units) between the parent's and clinician's ratings, whereas in 40 cases (57%) there was discordance (difference >0.25 CHAQ units). In 30 cases the parent rated the child's functional ability as worse than that observed by the clinician (i.e. the parent underestimated the child's function), whereas in 10 cases the parent rated the child's functional ability as better than that observed by the clinician (i.e. overestimated the child's function). Multivariate regression analysis showed that children's functional ability was overestimated by parents with increasing erythrocyte sedimentation rate and global articular severity score and underestimated with increasing level of pain. Among the functional areas of the CHAQ, the level of agreement was poorest in the areas of eating and hygiene and was best for activities., Conclusions: Discordance between proxy-reported and observed functional ability was frequent in our patients with JIA. The children's functional ability was overestimated by parents as the severity of arthritis increased and underestimated as the level of pain increased.

Objective: To examine the responsiveness of the disease activity measures more commonly used in juvenile chronic arthritis (JCA) clinical trials., Methods: Data were obtained from an open-label, non-controlled, multicentre trial designed to investigate the efficacy of methotrexate (MTX) in children with JCA. Outcome measures, including physician and parent global assessments, functional ability measures, articular variables, and laboratory indicators of systemic inflammation, were assessed at baseline and after 6 months of MTX treatment in 132 patients. Responsiveness of endpoint variables was evaluated by assessing the effect size (ES) and the standardized response median (SRM)., Results: Physician and parent global assessments were the more responsive instruments, showing ES and SRM above 1.0. Erythrocyte sedimentation rate, C-reactive protein, functional status measures and articular variables showed intermediate responsiveness. Morning stiffness, haemoglobin and platelet count were the least responsive instruments., Conclusion: The results of our analysis indicate that subjective estimations of the disease activity, either by the physician or parents, are the most responsive instruments in the assessment of the therapeutic response in children with JCA. The responsiveness of outcome measures in JCA should be further investigated in prospective controlled studies.