International League of Associations for Rheumatology classification of juvenile idiopathic arthritis: second revision, Edmonton, 2001

Preliminary MRI-based investigation of characteristics and prognosis of knee bone marrow edema in children with juvenile idiopathic arthritis

Introduction

Bone marrow edema (BME) is one of the main imaging characteristics of juvenile idiopathic arthritis (JIA) in children and rheumatoid arthritis (RA) in adult. Previous studies have shown that BME occurred in approximately 64% of adults with RA and was a key predictor of poor prognosis. But BME with JIA has not been of great concern. Therefore, we evaluated the prevalence, characteristics, and prognosis of knee joint BME in children with JIA.

Methods

In this retrospective study, we included children with JIA and knee joint involvement from January 2017 to December 2019. BME was evaluated according to the Juvenile Arthritis MRI Scoring system. Clinical characteristics were compared between the BME group and the non-BME group. The characteristics and prognosis of the BME were observed.

Results

A total of 128 children with 136 knee joint MRI data were identified, with 37 knee joints (27.2%) having BME. BME has positive correlation with synovial hypertrophy (Rs = 0.562, p = 0.019). There were significant differences in age (p = 0.010) and disease duration (p = 0.013) between the BME and non-BME groups. BME was found to be more common in older children and the patients with long duration of disease. Locations with BME were the lateral tibial plateau (17/37, 45.9%), the lateral weight-bearing femur (16/37, 43.2%), the medial tibial plateau and the medial femoral condyle (both with 15/37, 40.5%), and the medial weight-bearing femur (12/37, 32.4%). The lateral femoral condyle and both the lateral and medial sides of the patella were rarely involved. Of the 15 BME joints with the MRI follow-up data (interval 6.5 ± 3.0 months), the lesions disappeared or improved within 12 months after the treatments in 13 (86.7%) joints.

Conclusions

The prevalence of knee BME in JIA was 27.2%. There was positive correlation between BME and synovial hypertrophy. Older children and children with long disease duration had a higher risk for BME, which was commonly a late presentation and more likely involved the weight-bearing surfaces of the joint. The overall prognosis was satisfactory after the standard treatments.

Key Points • To the best of our knowledge, this paper is the first one to investigate the MRI manifestation in JIA focus on knee BME sign.

Severe Recurrent Fever Episodes With Clinical Diagnosis of Hemophagocytic Lymphohistiocytosis, Incomplete Kawasaki Disease and Systemic-Onset Juvenile Idiopathic Arthritis: A Case Report and Literature Review

The pathogeneses of recurrent fever are quite complicated when excluding repeated infections. Recurrent fever is a common symptom for autoinflammatory diseases, relapse of Systemic-onset juvenile idiopathic arthritis (SoJIA) and recurrent Kawasaki disease (KD). There are no specific diagnostic laboratory tests for the diseases. Some studies showed that KD was the precursor of hemophagocytic lymphohistiocytosis (HLH). Macrophage activation syndrome (MAS) is another form of HLH in SoJIA. Cytokine disturbances are considered to be involved in the pathogenesis of the diseases. We describe a Chinese female toddler that developed three separate fever episodes with eventual diagnose of SoJIA within about 10 months. The first episode was diagnosed as IKD, immunoglobulin nonresponsive KD, and HLH. The second and third episodes were diagnosed as IKD and SoJIA, respectively. The fever was hard to be relieved by antipyretics, and the peak axillary temperature was above 40°C. For every fever episode, infections were excluded. For the first episode, trends over time of hemoglobin, platelets, fibrinogen, and triglycerides indicated HLH, which was finally diagnosed and treated according to the HLH-2004 protocol. For the second episode 6 months later, after excluding an HLH relapse and infections, IKD was finally diagnosed. Oral aspirin was administered, and the HLH treatment was ceased. The third episode occurred 3 months later, and SoJIA was finally diagnosed. For each episode, except for relative tests, we only tested for cytokines interleukin-1β, interleukin-6, and interferon-γ, due to limited laboratory test availability. These cytokines were elevated during remission and rose much higher in the fever phases. The case showed the difficulty to differentiating the recurrent fever in clinical practice. Surveillance of routine laboratory parameters over time might reveal a trend that indicates possible disease, even when parameter values do not meet diagnostic criteria. Changes in cytokine profiles are promising markers for differentiating recurrent fever diseases in future. An unknown immunological defect for the case may contribute to the recurrent immunological insults, and we are following up the recurrence of fever episode.

Characterization of microbiota in systemic-onset juvenile idiopathic arthritis with different disease severities

BACKGROUND

Systemic-onset juvenile idiopathic arthritis (SoJIA) is one of most serious subtypes of juvenile idiopathic arthritis. Although the pathogenesis of SoJIA remains unclear, several studies have suggested a correlation between gut dysbiosis and JIA. Further understanding of the intestinal microbiome may help to establish alternative ways to treat, or even prevent, the disease.

AIM

To explore alterations in fecal microbiota profiles in SoJIA patients and to evaluate the correlations between microbiota and clinical parameters.

METHODS

We conducted an observational single-center study at the Pediatric Department of Peking Union Medical College Hospital. Children who were diagnosed with SoJIA at our institution and followed for a minimum period of six months after diagnosis were recruited for the study. Healthy children were recruited as a control group (HS group) during the same period. Clinical data and stool samples were collected from SoJIA patients when they visited the hospital.

RESULTS

The SoJIA group included 17 active and 15 inactive consecutively recruited children; the control group consisted of 32 children. Firmicutes and Bacteroidetes were the two most abundant phyla among the total sample of SoJIA children and controls. There was a significant difference among the three groups in observed species, which was the highest in the Active-SoJIA group, followed by the Inactive-SoJIA group and then HS group (Active-SoJIA vs HS: P = 0.000; and Inactive-SoJIA vs HS: P = 0.005). We observed a lower Firmicutes/Bacteroidetes ratio in SoJIA patients (3.28 ± 4.47 in Active-SoJIA, 5.36 ± 8.39 in Inactive-SoJIA, and 5.67 ± 3.92 in HS). We also observed decreased abundances of Ruminococcaceae (14.9% in Active-SoJIA, 17.3% in Inactive-SoJIA, and 22.8% in HS; Active-SoJIA vs HS: P = 0.005) and Faecalibacterium (5.1% in Active-SoJIA, 9.9% in Inactive-SoJIA, and 13.0% in HS; Active-SoJIA vs HS: P = 0.000) in SoJIA compared with HS. By contrast, the abundance of Bacteroidaceae was the highest in the Active-SoJIA group, followed by the Inactive-SoJIA and HS groups (16.5% in Active-SoJIA, 12.8% in Inactive-SoJIA, and 9.7% in HS; Active-SoJIA vs HS: P = 0.03). The Spearman correlation analysis revealed a negative correlation between Proteobacteria or Enterobacteriaceae and juvenile arthritis disease activity score on 27 joints (JADAS-27).

CONCLUSION

The composition of the intestinal microbiota is different in SoJIA patients compared with healthy children. The dysbiosis presents partial restoration in inactive status patients.

Tandem processes promoted by a hydrogen shift in 6-arylfulvenes bearing acetalic units at ortho position: a combined experimental and computational study

6-Phenylfulvenes bearing (1,3-dioxolan or dioxan)-2-yl substituents at ortho position convert into mixtures of 4- and 9-(hydroxy)alkoxy-substituted benz[f]indenes as result of cascade processes initiated by a thermally activated hydrogen shift. Structurally related fulvenes with non-cyclic acetalic units afforded mixtures of 4- and 9-alkoxybenz[f]indenes under similar thermal conditions. Mechanistic paths promoted by an initial [1,4]-, [1,5]-, [1,7]- or [1,9]-H shift are conceivable for explaining these conversions. Deuterium labelling experiments exclude the [1,4]-hydride shift as the first step. A computational study scrutinized the reaction channels of these tandem conversions starting by [1,5]-, [1,7]- and [1,9]-H shifts, revealing that this first step is the rate-determining one and that the [1,9]-H shift is the one with the lowest energy barrier.

Synthesis, structure, and ethene polymerisation catalysis of 1- or 2-silyl substituted bis[indenyl]zirconium(iv) dichlorides

The systematic syntheses of 1- and 2-substituted silylindenes, with a wide variety of substitution patterns on the silyl moiety, and their corresponding zirconocene dichlorides are presented. The rac- and meso-diastereomers of the 1-substituted zirconocene dichlorides can in most cases be separated. Instable zirconocenes were observed for certain substitution patterns. Two of the obtained zirconocene dichlorides, bis[2-(dimethylsilyl)indenyl]zirconium dichloride (4a) and bis[2-(trimethylsilyl)indenyl]zirconium dichloride (4b), were characterised by single crystal X-ray diffraction. On the basis of DFT results, the two compounds are geometrically similar, i.e. the additional methyl group on the silyl moiety only affects the conformational energy profile. Differences in their catalyst performance in the homopolymerisation studies with ethane are thus attributed to conformational control. For the remaining complexes, sterically less demanding silyl groups seem to be favoured with respect to the catalyst performance. All the 2-isomers have lower polymerisation activities than the unsubstituted bis[indenyl]zirconium dichloride/MAO system. Curiously, the rac-bis[1-(dimethylphenylsilyl)indenyl]zirconium dichloride/MAO system is found to be the most active catalyst in ethene homopolymerisations.