Background Although some features of dermatomyositis (DM) and polymyositis (PM) have been reported as possible prognostic indicators for cancer development, previous studies were small in size and were unable to establish a definitive relationship between neoplasms and DM and PM. Objectives To evaluate risk factors for developing malignancies in patients with DM and PM. Methods Meta‐analysis of the studies reported in the literature was performed to unveil risk factors for developing cancer among patients with DM and PM. The included studies were either cohort or retrospective case–control studies with information on cancer status. Risk for malignancy was determined as the odds ratio (OR) or weighted mean difference (WMD) with a 95% confidence interval (CI), determined by fixed and random effects models. Stata 10.0 software was used to identify possible publication bias. Results Twenty studies with 380 patients and 1575 controls were included in the analysis. The factors that may increase the risk of cancer in patients with DM and PM were older age (WMD 11·41, 95% CI 9·84–12·98), male sex (OR 1·92, 95% CI 1·49–2·48), cutaneous necrosis (OR 5·52, 95% CI 3·49–8·74) and dysphagia (OR 2·41, 95% CI 1·50–3·86), whereas those that may provide protection against cancer included arthritis (OR 0·38, 95% CI 0·24–0·61) and interstitial lung disease (OR 0·32, 95% CI 0·20–0·51). Conclusions Our data suggest that age, sex, cutaneous necrosis, dysphagia, arthritis and lung complications may influence susceptibility to cancer in patients with DM and PM.

Polymyositis (PM) and dermatomyositis (DM) are idiopathic inflammatory myopathies. Genetic variability in human leukocyte antigen (HLA) genes plays an important role in the pathogenesis of PM and DM. However, few studies on the subject in Chinese populations have been reported thus far.

Background: To describe the clinical characteristics and explore the factors related to the MRI remission of sacroiliitis in patients with enthesitis-related arthritis (ERA). Methods: Patients with ERA from 2018–2022 in our medical center were retrospectively reviewed, which identified according to Pediatric Rheumatology International Trials Organization (PRINTO) criteria. Demographics, clinical characteristics, examinations, and treatments were described. Univariate and multivariate logistic regression models were used to analyze the factors related to MRI remission of sacroiliitis in ERA. Results: This retrospective study included 160 ERA patients (51.9% male) with a mean onset age of 9.2 ± 3.0 years. There were 144 cases (81.9%) with peripheral arthritis, and the hip, knee, and ankle joints were the most commonly involved joints. Enthesitis occurred in 48 cases (30.0%), and sacroiliitis occurred in 142 cases (88.5%) at diagnosis. Human leukocyte antigen (HLA)-B27 was positive in 33 cases (17.1%), and acute uveitis occurred in 3 cases (1.9%). The majority of patients (93.7%) were treated with disease-modifying anti-rheumatic drugs (DMARDs), and 60% with biologics. Among 62 patients with MRI-defined sacroiliitis, 27 (43.5%) cases showed improvement in the sacroiliac joint lesion after treatment. Multivariate logistic regression analysis showed that duration from onset to diagnosis of less than 3 months (OR = 3.609, 95% CI: 1.068–12.192) and active joints of more than 4 (OR = 4.916, 95% CI: 1.006–24.037) were independent factors. Conclusion: We highlighted differences in ERA clinical characteristics. Patients with a shorter diagnosis time and more joint involvement improved more significantly in sacroiliac joint lesions after treatment.

Eculizumab, a recombined humanized monoclonal antibody which possesses high affinity for the complement protein C5, is a therapeutic agent utilized in the treatment of atypical hemolytic uremic syndrome (aHUS) by inhibiting the terminal complement complex C5b-9. In a pediatric patient with aHUS of 14 months, the administration of eculizumab therapy was accompanied by the inclusion of meningococcal vaccine as part of the national immunization program. Notably, no other antibiotics were administered prior to or during the course of eculizumab treatment. Moreover, there were no occurrences of infusion reactions or meningococcal infections observed throughout the course of treatment. Due to the presence of anti-factor H antibodies and insufficient recovery, glucocorticoids and eculizumab were administered at week 0 and week 1, followed by the initiation of mycophenolate mofetil (MMF) at a dosage of 250 mg (approximately 548 mg/m²) per day starting from Day 10. Due to the recovered of complement antibody after 8 doses of eculizumab, the therapeutic interval was extended from once every 3 weeks to once a month since 9th administration. We experienced and successfully treated a rare case of aHUS with eculizumab in a 14-month-old Chinese pediatric patient.

Introduction Enthesitis-related arthritis (ERA) is a category of juvenile idiopathic arthritis (JIA). The complications of JIA include pain, muscle weakness, limited movement and worsening quality of life. Yoga is an effective exercise therapy for rheumatoid arthritis and may have similar benefits for JIA. Considering the limitation of yoga for strengthening muscles, combined yoga and resistance training (CYRT) may compensate for the shortcomings and provide more benefits for JIA patients. Despite this, there is currently a lack of studies investigating the effectiveness of CYRT for JIA patients. Due to the inaccessibility of traditional exercise therapy, home-based exercise is needed. The study aims to assess the effectiveness of home-based CYRT on JIA. Methods and analysis This is a 12-week randomised single-blind controlled trial study. 60 patients with ERA will be randomised into two groups: the home-based exercise group (HBE) and the health education (HE) group. The HBE group (n=30) will perform the CYRT programme 3 times a week at home for 12 weeks and receive HE. The HE group (n=30) will only receive HE. The outcomes include primary outcome (pain levels) and secondary outcomes (lower limb muscle strength, motion range of joint, aerobic fitness, function ability, fatigue levels, mental health, quality of life and blood biomarkers). The assessments will be conducted at baseline, postintervention (12 weeks) and follow-up (24 weeks). Data will be analysed by intention to treat. Ethics and dissemination This study has been approved by the Ethics Committee of Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine in December 2023 (approval no. XHEC-C-2023-059-3). This study will require informed consent from all subjects and guardians of children under 18 years of age. The findings will be published in a peer-reviewed journal and international conferences. Trial registration number ChiCTR2300073446.

Background: Dent disease is a group of inherited X-linked recessive renal tubular disorders. This group of disorders is characterized by low molecular weight proteinuria (LMWP), nephrocalcinosis, hypercalciuria and renal failure.Case presentation: Here we report one 11-year-old Chinese boy (proband) and one 13-year-old Chinese boy who was proband's cousin, both presented with massive proteinuria. Further laboratory examinations revealed a lack of nephrocalcinosis, nor any other signs of tubular dysfunction, but only LMWP and hypercalciuria. There was no abnormality in growth, renal function or mineral density of the bones. A novel deletion (c.1448delG) in the CLCN5 gene was identified, resulting in a frame shift mutation (p.Gly483fs). The proband's and his cousin's mothers were found to be the carrier of this mutation.Conclusions: In this study, we have found a novel frameshift mutation (c. 1448delG) at exon 11 of the CLCN5 gene which leads to Dent disease 1, expanding the spectrum of CLCN5 mutations.