IntroductionAdolescents and young adults with rare diseases face a “medical cliff” when they age out of paediatric services, losing established care relationships and disease-specific expertise. Most rare diseases begin in childhood, since 69.9% of catalogued rare diseases are of exclusively paediatric onset. The problem is acute in China, where an estimated 20 million people live with a rare disease and systematic transitional care pathways remain largely absent.MethodsWe describe the development and implementation of an integrated paediatric–adult continuity of care model for rare diseases, the adult population it serves, and early operational indicators of its feasibility. This retrospective, descriptive analysis used clinical service data from the Children's Hospital of Fudan University, Shanghai, over a 38-month window (3 January 2023–25 February 2026); the model was implemented from September 2023. Its four components were expanded treatment authority with proactive management; a multidisciplinary paediatric–adult joint clinic; proactive follow-up with dynamic evaluation; and medical social work with psychosocial support. The programme admits patients aged 18–35 years.ResultsIn total, 2,341 patients aged ≥18 years generated 4,847 outpatient, emergency, and inpatient encounters (mean age at first encounter 22.7 ± 5.9 years; 51.7% female). Annual encounter volumes rose from 240 in 2023 to 1,412 in 2024 and 2,628 in 2025, with a further 567 in January and February 2026. Return attendances accounted for 4,373 encounters (90.2%), and 843 patients (36.0%) attended more than once. The leading specialities were neurology (29.1%), hepatology (12.2%), and endocrinology (8.1%); most encounters were by Shanghai residents (54.8%).DiscussionRepeat attendance measures utilisation rather than adherence, and rising volumes likely reflect progressive implementation and growing awareness rather than model effectiveness. With enabling policies, paediatric hospitals can deliver continuous care for adult rare disease patients, although these indicators describe service activity rather than clinical or patient-reported outcomes. The model is best characterised as continuity of care delivered within paediatric services rather than as a conventional transition programme, and offers a replicable blueprint for health systems lacking established adult subspeciality services; cross-provincial health insurance portability remains the single most critical barrier to nationwide scale-up.

Biallelic mutations in aminoacyl-tRNA synthetase genes have been implicated in a variety of multisystem disorders. Nonetheless, the correlation between cytosolic IARS (which encodes isoleucyl-tRNA synthetase) and childhood interstitial lung disease (chILD) as well as pulmonary alveolar proteinosis (PAP) has yet to be established. We characterized the clinical features of four pediatric patients exhibiting progressive chILD/PAP alongside extrapulmonary manifestations (growth retardation, intellectual impairment, hypotonia, and liver disease). Whole exome sequencing was performed to confirm that biallelic IARS mutations are the etiological cause of the disease, and protein structural prediction was conducted for the identified pathogenic mutations via AlphaFold modeling. Periodic-Acid Schiff (PAS) and Oil-Red O (ORO) staining, along with western blotting and transmission electron microscopy of bronchoalveolar lavage fluid (BALF) and single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) were used to characterize the disease phenotype and explore potential pathogenic mechanisms. All four patients were confirmed to possess compound heterozygous IARS variants, inherited in trans from unaffected parents. Analysis of BALF revealed characteristic lipoprotein accumulation associated with PAP, evidenced by positive PAS and ORO staining. Additionally, surfactant proteins exhibited abnormal expression, accompanied by notable secondary lysosome formation and vacuolization within alveolar macrophages. scRNA-seq of PBMCs identified a specific depletion of CD14 + CD16+ intermediate monocytes and a transcriptional downregulation of phagosome/lysosome pathways in CD14 + classic monocytes. These findings suggest a potential intrinsic defect in the monocyte/macrophage lineage, potentially contributing to surfactant clearance dysfunction. Our findings expand the phenotypic spectrum of IARS-related disorder by identifying chILD/PAP as a core and clinically significant pulmonary manifestation of biallelic IARS mutations. This study establishes IARS as a novel pathogenic gene for chILD/PAP and provides preliminary insights into the immune-related pathogenic mechanisms, highlighting the need for genetic screening of IARS variants in pediatric patients with unexplained respiratory failure and multisystem involvement.

Background and objective: The heterogeneity of respiratory disease and concomitant abnormalities are poorly studied in primary ciliary dyskinesia (PCD). We sought to delineate the the evolution of clinical features with age and genotype.Methods: We conducted a multicenter cross-sectional study of PCD patients in China, systematically collecting clinical, laboratory, and genetic data. Linear regression analysis were used to assess associations between clinical features and genotype.Results: We enrolled 203 patients with a median age of 14.8 years. The most frequently involved genes were DNAH5 (n = 61), DNAH11 (n = 42), and CCDC39/40 (n = 23). The mean annual decline in percent predicted forced expiratory volume in 1 second (ppFEV1) was 1.03% (standard error: 0.163). Mean number of affected lobes increased from 0.69 per person in 0-6 years age group to 2.84 in adults (P < 0.001). Compared with DNAH5 mutation carriers, those with DNAH9 mutations exhibited fewer lobes affected by consolidation (-0.56 fewer; 95% CI, -0.96 to -0.15; P = 0.008) and bronchiectasis (-0.58 fewer; 95% CI, -1.13 to -0.02; P = 0.004). In contrast, DNAH11 mutation carriers demonstrated higher ppFEV1 (11.60% higher; 95% CI, 1.55 to 21.66; P = 0.024). Congenital heart diseases were more prevalent among patients carrying DNAH11 (P < 0.001) and DNAH9 mutations (P < 0.001).Conclusions: Our work addressed a critical gap in genotype-phenotype correlations among East Asian PCD populations. Specifically, we found that patients with DNAH9 or DNAH11 mutations demonstrate milder respiratory disease but higher rates of congenital heart diseases.

Background Although Mycoplasma pneumoniae pneumonia (MPP) is a leading cause of pediatric community-acquired pneumonia, the specific clinical impact of respiratory pathogen co-detection remains incompletely understood. Methods In this retrospective cohort study, we analyzed data from 3081 children hospitalized with confirmed MPP at a single center in China (January 2023-December 2024). Based on comprehensive respiratory pathogen testing, patients were classified into MPP mono-infection (n = 1173) or MPP co-detection (n = 1908) groups. Severe MPP (SMPP) was defined as a composite outcome per national guidelines. The primary outcome was the incidence of SMPP; secondary outcomes included specific complications, healthcare utilization, and costs. Stratified analysis by co-detection pattern (single virus, single bacterium, viral-bacterial, and multiple viruses) was performed. Multivariable logistic regression was used to assess the independent association of co-detection with SMPP, adjusting for sex, age, platelet count, C-reactive protein (CRP) level, and D-dimer level. Results The co-detection rate was 61.9% (1908/3081). Among co-detected cases, single-viral detection was most common (41.8%), followed by viral-bacterial detection (19.1%). Adenovirus (33.5%) and rhinovirus (32.1%) were the predominant single viruses. The co-detection group exhibited a significantly higher incidence of SMPP (51.8% vs. 47.3%, P = 0.018), higher total hospitalization costs, longer hospital stays, and longer durations of cough and fever (all P < 0.001). Stratified analysis revealed that the viral-bacterial co-detection subtype consistently exhibited the most severe outcomes. After adjusting for sex, age, platelet count, CRP level, and D-dimer level, pathogen co-detection was an independent risk factor for SMPP [adjusted odds ratio (OR) = 1.31; 95% confidence interval = 1.11-1.56; P = 0.002]. Elevated D-dimer levels (adjusted OR = 3.66) and older age were also significant independent predictors. Conclusions Respiratory pathogen co-detection is prevalent in children with MPP and is independently associated with disease progression to SMPP (as defined by guideline criteria), prolonged hospitalization, and increased healthcare costs. The viral-bacterial co-detection pattern is associated with the greatest risk. These findings underscore the importance of comprehensive pathogen screening in the management of pediatric MPP.

OBJECTIVE This study aimed to characterize pediatric idiopathic pulmonary hemosiderosis (IPH) and assess whether adding bronchial artery embolization (BAE) to glucocorticoid (GC) therapy reduces the cumulative risk of disease recurrence. METHODS We conducted a retrospective cohort study of children with IPH between January 2003 and January 2020 from a single center. Demographic, clinicopathologic, therapeutic, and outcomes data were extracted. The primary outcome was cumulative recurrence of hemorrhage, analysed using the Andersen-Gill models. The secondary outcomes included time to first recurrence and change in hemoglobin levels from baseline to six months after treatment. RESULTS A total of 63 patients were included, with 44 (70%) receiving BAE plus GC treatment and 19 (30%) receiving GC treatment alone. The median age at diagnosis was 4.6 years (interquartile range: 2.1–7.6), and 28 (44%) were female. During a median follow-up period of 36 months (range, 0.7–120), 87 relapses occurred in the GC with BAE group versus 24 in the GC without BAE group. The adjusted hazard ratio was 1.66 (95% confidence interval [CI], 0.58–4.74) for the GC with BAE group compared with GC alone. The corresponding hazard ratio for time to first recurrence was 0.98 (95% CI, 0.39–2.44). Changes in hemoglobin levels did not differ significantly between the two groups (–20.5 [95% CI, − 27.4 to − 0.7] vs − 14.0 [95% CI, − 26.7 to 14.4], mean difference − 6.5 [95% CI, − 19.0 to 6.0], P = 0.30). CONCLUSIONS Our data do not support the addition of BAE to conventional GC therapy as routine primary treatment for pediatric IPH.

IntroductionLittle was known about the characteristics of low respiratory tract (LRT) microbiota of refractory M. pneumoniae pneumonia (RMPP) in children before and after the COVID-19 pandemic.MethodsForty-two children diagnosed with RMPP in 2019 (Y2019 group) and 33 children diagnosed with RMPP in 2023 (Y2023 group), entered into the study. The characteristics of the clinical findings were examined, and the LRT microbiota was analyzed by metagenomic next generation sequencing.ResultsThe ratio of consolidate, atelectasis, lung necrosis, and erythema multiforme in Y2023 group was significantly higher than that in Y2019 (P<0.05). Mycoplasmoides pneumoniae was the top species of the LRT microbiota in both groups. The rate of macrolide resistance MP in Y2023 was significantly higher than that in Y2019 (P<0.05), and the mutant site was all 23S rRNA A2063G. There were no significant differences in α-diversity and β-diversity of LRT microbiota between Y2019 and Y2023 group. Trichoderma citrinoviride, Canine mastadenovirus A, Ralstonia pickettii, Lactococcus lactis, Pseudomonas aeruginosa were the biomarkers of LRT microbiota in children with RMPP of Y2023. The abundance of Mycoplasmoides pneumoniae positively correlated with the levels of D-dimer and LDH, negatively correlated with the counts of CD3+ T cells, CD8+ T cells, CD19+ B cells and CD16+CD56+ NK cells.DiscussionOur study showed that high abundance of MP was correlated with the severity of RMPP and decrease of immune cells. Trichoderma citrinoviride, Canine mastadenovirus A, Ralstonia pickettii, Lactococcus lactis, Pseudomonas aeruginosa were the biomarkers in microbiota of LRT in children with RMPP post COVID-19 era.

There is a recent global surge in Mycoplasma pneumoniae pneumonia (MPP). However, the key immune factors that contribute to the advancement of the disease remain unknown. Hence, we conducted this study to uncover the immunological profile in children affected by MPP. This study enrolled children visiting Children’s Hospital of Fudan University from December 2023 to April 2024, including 34 healthy controls, 51 severe MPP (S-MPP), 27 non-severe MPP (NS-MPP), and 34 non-MPP pneumonia (NMP) cases. Their blood samples were analyzed using flow cytometry, multi-cytokine assays, and antibody detection methods. Compared with NMP cases, MPP cases displayed higher frequencies of natural killer T cells, classical monocytes, and monocytic myeloid-derived suppressor cells. Notably, both T helper type 1 and activated regulatory T cells were more abundant in MPP cases, particularly in S-MPP, whereas CD8 + T cells displayed an exhaustion phenotype. The proportion of naïve B cells was reduced, while functional B cells, including memory B cells and plasmablasts, increased in S-MPP. 12 out of 95 clinical laboratory indicators and 3 out of 48 cytokines significantly differed between S-MPP and NS-MPP. Finally, we performed logistic and LASSO regression analyses and developed a predictive model for S-MPP that incorporates naïve B cell percentage from flow cytometry, cholinesterase from clinical laboratory tests, and interleukin 18 from the cytokine assay. These results clarify the immunological features in pediatric MPP cases, and identify novel markers for severe cases, providing insights for early diagnosis and immunological management in affected children.

OBJECTIVES:To investigate the associations between maternal fine particulate matter (PM2.5) and PM<10 µm in aerodynamic diameter (PM10) exposure during pregnancy and bronchopulmonary dysplasia (BPD) incidence in very preterm infants (VPIs, gestational age (GA)<32 weeks), with emphasis on trimester-specific susceptibility and effect modification by clinical and environmental factors. DESIGN:Retrospective observational cohort study. SETTING:A tertiary neonatal intensive care unit in China, 2016-2022. PARTICIPANTS:2223 VPIs hospitalised during the study were enrolled after excluding infants with severe congenital malformations, those who abandoned treatment and those who died before discharge. Of these, 59.8% were male. PRIMARY AND SECONDARY OUTCOME MEASURES:We evaluated the effect of maternal PM2.5 and PM10 exposure on BPD, adjusted for additional ambient air pollutants (ozone and nitrogen dioxide) as well as demographic and clinical characteristics. We also calculated trimester-specific PM exposure effects and conducted stratified analyses by sex, GA, birth weight (BW) and conception season, with formal interaction testing. RESULTS:Among 2223 VPIs included in this study, 684 (30.8%) were diagnosed with BPD. Strong correlations were observed between PM exposure and BPD, with each IQR increase during the entire gestational period associated with ORs of 1.254 (95% CI 1.062 to 1.484) for PM2.5 and 1.350 (95% CI 1.142 to 1.596) for PM10 in the single-pollutant model. The strongest associations were observed during the second trimester, and the same association was also identified in the two-pollutant model. Stratified analysis revealed a larger OR estimate in subgroups with lower BW (<1500 g) and smaller GA (<28 weeks). CONCLUSIONS:Maternal PM exposure, particularly during the second trimester, is significantly associated with BPD in VPIs, with heightened vulnerability in males and infants with lower GA and BW. These findings underscore the need for prenatal air quality interventions and targeted monitoring of high-risk subgroups. Future research should explore PM-induced mechanisms of fetal lung injury and validate these associations in multicentre cohorts.

Pneumonia is the leading cause of morbidity and mortality in children and needs rapid and accurate pathogenic diagnosis. The aim of this study was to evaluate the diagnostic value of bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing (mNGS) and conventional microbiological tests (CMTs) for pathogen detection in children with severe or refractory pneumonia. In this retrospective study, the clinical data of 127 children with severe or refractory pneumonia admitted to the respiratory department from June 2021 to March 2022 were analyzed. BALF mNGS and CMTs were utilized for pathogen diagnosis and comparison of their detection performance for different pathogens. The pathogenic diagnosis rate was 95.28% (121/127) by combining mNGS and CMTs. mNGS had significantly higher overall (96.06% vs 72.44%, P < 0.001), bacterial (69.29% vs 12.60%, P < 0.001), and fungal (11.81% vs 3.15%, P = 0.009) detection rates than CMTs. However, there was no significant difference of detection rates between them for respiratory viruses (33.86% vs 33.75%, P = 0.99) and Mycoplasma pneumoniae (48.03% vs 45.67%, P = 0.71). The sensitivities of mNGS for total pathogens, bacteria, and fungi were 99.17%, 100%, and 87.50%, respectively, which were higher than those of CMTs. CMTs for M. pneumoniae had the highest sensitivity (91.23%) compared with mNGS (89.47%) and multiplex PCR (88.57%). For respiratory viruses, mNGS and mPCR had similar sensitivities (97.67% vs 96.43%). mNGS was superior to CMTs in bacterial and fungal detection, while it was comparable to multiplex PCR for the detection of M. pneumoniae and respiratory viruses. Different detection methods should be rationalized for different pathogens. IMPORTANCE:This study on 127 patients with severe and refractory pneumonia showed that mNGS was significantly superior to CMTs in terms of bacterial and fungal detection. We also found that multiplex PCR assay was comparable to mNGS for the detection of Mycoplasma pneumoniae and respiratory viruses and may have greater application advantages in combination with CMTs, such as M. pneumoniae IgM. For severe and refractory pneumonia, or when empiric treatment is not effective, collecting BALF for mNGS can help to quickly identify the causative organisms at an early stage. It is also important to choose more appropriate methods or combinations for different pathogens.

Mycoplasma pneumoniae(M.pneumoniae),primarily trans-mitted through respiratory droplets when infected individ-uals cough or sneeze,is a common cause of community-acquired pneumonia,especially among school-age children and adolescents.The infection occurs endemically with an epidemic peak every few years.

Background:In 2023, China witnessed an earlier and more widespread outbreak of Mycoplasma pneumoniae pneumonia (MPP). To address this situation, an online training program was designed to enhance the knowledge of MPP among pediatricians in Shanghai, China.Methods:An online training program on the diagnosis and treatment of MPP, guided by Kern's six-step approach, was developed by the Shanghai Pediatric Clinical Quality Control Center. A pre- and post-training survey was conducted using a 20-item self-administered questionnaire to investigate the pediatricians' knowledge of MPP. A linkage mechanism was established to match pretest/posttest questionnaires using personal identifiers. Paired t-tests and McNemar tests were performed to measure the differences, as appropriate, between pre- and post-training groups. A higher survey score indicated better knowledge.Results:There were 289 participants performed pre- and post-tests. The average age of the respondents was 38.7 years (standard deviation: 8.9). Over 80% of the participants were primary (32.5%) and intermediate (47.8%) pediatricians. Those from specialized hospitals accounted for the highest proportion (41.5%). The post-training group achieved significantly higher total scores than the pre-training group (91.3 vs. 67.7, t=22.48, P<0.001), regardless of the professional titles or hospital levels (all P<0.001). The accuracy rates of each question increased significantly in the post-training group (all P<0.001).Conclusions:The online training program effectively enhanced pediatricians' understanding of diagnosing and treating MPP. It is recommended to maintain continuous education and training targeting all healthcare providers.

BackgroundDuring the coronavirus disease 2019 (COVID-19) pandemic, the infection of Mycoplasma pneumoniae (MP) decreased significantly. At the beginning of the summer of 2023, there was an increasing trend of MP infection in China and the MP pneumonia (MPP) is surging when it comes to the school season and lasts for several months which has attracted widespread attention.ObjectiveThis study aims to investigate the prevalent characteristics of the MP and the difference between the COVID-19 pandemic and the post in Shanghai, China.MethodsThe demographic information and the results of laboratory pathogen detection from July 2021 to May 2024 were collected and analyzed to find out the prevalent characteristics of MP. Two periods, during the COVID-19 pandemic and the post-pandemic, were divided and compared. The P1 genotyping and macrolide resistance-associated gene of 23 s rRNA were detected using the remaining MP-positive samples.ResultsDuring the COVID-19 pandemic, the prevalence of the MP has significantly decreased. Female children are more susceptible to MP infection than the male. The school-aged group (>6 years) had the highest infection rate. The rate of MP P1 genotype during post panel is higher than that during COVID-19 pandemic, which is dominant from July 2021 to May 2024, while the macrolide-resistant associated mutations (A2063G) keep high percentage during or post pandemic.ConclusionAfter the COVID-19 pandemic, an outbreak of MP infection occurred from summer onwards in 2023 with children in Shanghai, China. Immunity debt and high rate of macrolide-resistance may take effects in this MP epidemic. Continuous surveillance of MP is necessary to help to alert the prevalence of MPP.

BACKGROUND:MIRAGE syndrome is a rare autosomal dominant genetic disorder.METHODS:We studied a 15-month-old girl with growth retardation and refractory respiratory infections.RESULTS:The patient had thrombocytopenia and was positive for Epstein-Barr virus, cytomegalovirus IgM and IgG, and herpes simplex virus type I and II IgG. The genomic analysis reported a heterozygous de novo SAMD9 c.2944C > T (p.Arg982Cys) pathogenic variant. She improved after antibiotic treatments, but finally died due to severe recurrent infection.CONCLUSIONS:Patients with MIRAGE syndrome could have various clinical presentations. Infections from mixed pathogens are common, which require adequate coverage for bacteria, viruses, and fungi.

Limited evidence was available on ambient air pollution and pediatric atopic dermatitis (AD). The study aimed to evaluate the associations between short-term exposure to air pollutants and outpatient visits for pediatric AD. From 2016-2018, we collected data on six criteria air pollutants (PM2.5, PM10, NO2, SO2, CO and O3) and daily outpatient visits for pediatric AD in 66 hospitals, covering all districts in Shanghai, China. The over-dispersed Poisson generalized additive model (GAM) was applied to fit the associations of criteria air pollutants with hospital visits. Two-pollutant models were fitted and stratified analyses by sex, age and season were conducted. We identified 477,833 outpatient visits for pediatric AD. Each interquartile range (IQR) increase in PM2.5 (IQR: 30.9 μg/m3), PM10 (8.9 μg/m3), NO2 (25.5 μg/m3), SO2 (5.8 μg/m3) and CO (0.283 mg/m3) on the concurrent day was significantly associated with increments of 2.08 % (95 % CI: 0.53 %, 3.65 %), 2.53 % (95 % CI: 0.87 %, 4.22 %), 8.14 % (95 % CI: 6.24 %, 10.08 %), 5.67 % (95 % CI: 3.58 %, 7.80 %), and 2.27 % (95 % CI: 0.70 %, 3.87 %) in pediatric AD outpatient visits, respectively. The effects of NO2 remained robust after adjustment for other air pollutants. The exposure-response curves for PM2.5 and PM10 were steeper for moderate-lower concentrations, with a flatten curves at high concentration; nearly linear relationships were found for NO2. Higher associations of NO2 exposure on AD were detected in children under 6 years old (p=0.01); and we observed larger effect of air pollutants in cool seasons (p<0.001 for PM2.5, PM10, NO2 and CO; p=0.043 for SO2). This study indicated that short-term exposure to air pollution could increase risk of outpatient visits for pediatric AD.

BackgroundNoninvasive positive-pressure ventilation (NPPV) can be effective in children with acute asthma. However, clinical evidence remains limited. The objective of the meta-analysis was to systematically assess NPPV's effectiveness and safety in treating children with acute asthma.MethodsRelevant randomized controlled trials were obtained from electronic resources, including PubMed, Embase, Cochrane's Library, Wanfang, and CNKI databases. The influence of potential heterogeneity was taken into account before using a random-effect model to pool the results.ResultsA total of 10 RCTs involving 558 children with acute asthma were included in the meta-analysis. Compared to conventional treatment alone, additional use of NPPV significantly improved early blood gas parameters such as the oxygen saturation (mean difference [MD]: 4.28%, 95% confidence interval [CI]: 1.51 to 7.04, p = 0.002; I-2 = 80%), partial pressure of oxygen (MD: 10.61 mmHg, 95% CI: 6.06 to 15.16, p < 0.001; I-2 = 89%), and partial pressure of carbon dioxide (MD: -6.29 mmHg, 95% CI: -9.81 to -2.77, p < 0.001; I-2 = 85%) in the arterial blood. Moreover, NPPV was also associated with early reduced respiratory rate (MD: -12.90, 95% CI: -22.21 to -3.60, p = 0.007; I-2 = 71%), improved symptom score (SMD: -1.85, 95% CI: -3.65 to -0.07, p = 0.04; I-2 = 92%), and shortened hospital stay (MD: -1.82 days, 95% CI: -2.32 to -1.31, p < 0.001; I-2 = 0%). No severe adverse events related to NPPV were reported.ConclusionsNPPV in children with acute asthma is associated with improved gas exchange, decreased respiratory rates, a lower symptom score, and a shorter hospital stay. These results suggest that NPPV may be as effective and safe as conventional treatment for pediatric patients with acute asthma.

1 病例资料 女,8 岁,因"反复咳嗽喘息 10 月余,加重伴发热 2 月"于 2019 年 9 月 2 日就诊于复旦大学附属儿科医院呼吸科(我科).

Background:The management of LT patients during COVID-19 pandemic is important. Immunosuppressants (IS) are key therapy agents after liver transplant. Different ISs have different side effects. Calcineurin inhibitor (CNI) may lead to metabolic acidosis while mycophenolate mofetil (MMF) showed rare nephrotoxicity. We report a post-liver transplant girl who was infected with SARS-CoV-2, developing a severe mixed acidosis 3 months after the transplantation. Her acidosis was improved after withdrawing of MMF, leading the suspicion that acidosis maybe a rare side effect of MMF.Case presentation:A girl was admitted to our hospital due to SARS-CoV-2 infection, 3 months before admission the patient received LT due to Niemann-Pick disease (NPD). During hospitalization, blood gas analysis showed severe mixed acidosis. To relieve mixed acidosis, the patient was given oral rehydration salt and liquid replacement therapy. Considering that immunosuppressants may cause metabolic acidosis, dose of CsA was decreased and MMF was discontinued.Results:However, liquid replacement therapy and decreased CsA dose cannot improve the condition. As an attempt, MMF was discontinued, and 3 days later, the girl's acidosis was relieved, the latest blood gas analysis was normal with the original dose of CsA and no use of MMF or other IS. In addition, we used Naranjo Scale to see if adverse drug reactions (ADRs) existed. The final score was 6 which means MMF contributes to acidosis probably.Conclusion:The girl's mixed acidosis cannot be explained by Niemann-Pick disease and SARS-CoV-2 infection. CNIs could cause metabolic acidosis but declining the dose of CsA didn't improve her acidosis while withdrawing MMF showed a good effect. Together with the Naranjo Scale result, we suspect that acidosis maybe a rare side effect of MMF.

BACKGROUND:Medical complexity of childhood interstitial lung disease (chILD) with connective tissue disease (CTD) poses a considerable challenge to pediatricians. METHODS:Clinical characteristics, laboratory findings, pulmonary function tests (PFTs), treatments and outcomes obtained for patients with CTD-chILD were analyzed in a prospective study. RESULTS:Patients' median age at diagnosis was 7 years old. About 29.4% (15/51) suffered rapidly progressive childhood ILD (RP-chILD) with a high mortality rate (33.3%, 5/15), and the incidence of RP-chILD in juvenile idiopathic inflammatory myopathies was as high as 41.6% and the mortality rate was 30% (3/10). More than 70% patients had decreased diffusion capacity. The mean interval from symptoms-onset to diagnosis was 11.3 months. Compared to chILD with known CTD, the chILD proceeded CTD had a longer diagnosis interval, higher mortality, hospital stays and costs (P < 0.05). Lung imaging (33.3%) and lung function (72.7%) were partially reversible. The average survival time was 68.6 months. Cox univariate analysis showed that HRCT score ≥3, experiencing RP-chILD, cyanosis, acute respiratory distress syndrome (ARDS) and CD4 T cell <200 were significant predictors of death for chILD, whereas Cox multivariate analysis showed that ARDS was significant predictor of death for CTD-chILD, while IVIG support combined with corticosteroids and immunosuppressants was a protective factor. CONCLUSIONS:Care providers should conduct an assessment for CTD in chILD as a longer interval between the diagnosis of chILD and the CTD is associated with increased mortality. Complications as ARDS predict poor outcome in CTD-chILD, while IVIG support combined with corticosteroids and immunosuppressants is a protective factor.

Background: Bronchial Dieulafoy's disease (BDD) is a vascular malformation characterized by the presence of a dysplastic artery in the bronchial submucosa. It is very rare in children but potentially fatal due to life-threatening hemoptysis. Case Description: An 8-year-old boy and a 6-year-old girl were referred to our hospital with recurrent moderate to massive hemoptysis. Intraluminal protrusions with a tendency to bleed were found by bronchoscopy in both patients. Computed tomography angiography (CTA) revealed an abnormal bronchial artery in one patient and a small intraluminal nodule with contrast enhancement in the other. An enlarged bronchial artery and bronchial-to-pulmonary fistulae corresponding to the lesion site were detected by bronchial arteriography in both patients. Based on the radiological findings, the diagnosis of BDD was established. Subsequent bronchial artery embolization (BAE) was successful, and no recurrence of hemoptysis was observed during the 15- to 18-month follow-up. Conclusions: Our cases highlighted the importance of considering BDD in the context of hemoptysis and endobronchial protrusion in children. Bronchial arteriography plays a critical role in diagnosis, especially in cases where CTA does not reveal vascular malformations. Early identification is essential as biopsy is contraindicated. BAE may be an appropriate treatment to improve the prognosis of children with BDD.