Objective:To explore the clinical characteristics, diagnosis and treatment strategies, and prognosis of pulmonary embolism (PE) complicating childhood rheumatic diseases.Methods:A retrospective case series study was performed on the demographic data, laboratory indicators, imaging features, treatment regimens, and follow-up data of 8 children with rheumatic diseases complicated by PE who were admitted to the Department of Rheumatology and Immunology, Capital Center for Children′s Health, Capital Medical University from January 2014 to October 2023.Results:Among the 8 children, there were 4 boys and 4 girls, with an age of 12.0 (7.5, 13.0) years. Among the primary diseases, there were 3 cases of systemic lupus erythematosus, 2 cases of Beh?et′s disease, 2 cases of Takayasu arteritis, and 1 case of antiphospholipid syndrome. All children developed PE during the active phase of the primary disease. PE was detected at the onset of the primary disease in 3 cases, and the median time from the diagnosis of the primary disease to the development of PE was 10.0 (6.0, 25.0) months in the remaining 5 cases. Fever was present in all 8 children, 4 cases were accompanied by chest tightness, dyspnea, etc., and 2 cases only presented with fever. Laboratory examinations revealed the following results: erythrocyte sedimentation rate was 42.0 (17.0, 78.0) mm/1 h, high-sensitivity C-reactive protein was 12.7 (2.6, 78.7) mg/L, white blood cell count was 9.6 (7.2, 18.7)×10 9/L; D-dimer was 2.3 (0.9, 6.2) mg/L; and hemoglobin was (109±16) g/L.Imaging examinations revealed that 5 cases had involvement of the bilateral lower pulmonary arteries, 5 cases had peripheral embolism, and 3 cases had central PE. Complications included 3 cases of deep vein thrombosis, 2 cases of intracranial venous sinus thrombosis, and 1 case of mild pulmonary hypertension.In terms of treatment, 7 cases received anticoagulation with heparin followed by warfarin. Immunomodulation was mainly based on glucocorticoids combined with immunosuppressants, and 4 cases were combined with biological agents. The follow-up time of 4.17 (1.75, 7.17) years, the time for complete absorption of PE was 10.5 (6.0, 18.0) months; all 8 children had no target events, with no recurrence or chronic thromboembolic pulmonary hypertension, and the pulmonary artery remodeling was good. Conclusions:PE complicating childhood rheumatic diseases is closely related to the activity of the primary disease. The clinical manifestations are insidious, with fever as the main symptom. Imaging examination is the key to diagnosis.Early adoption of heparin followed by warfarin anticoagulation and glucocorticoids combined with immunosuppressants and (or) biological agents to control the primary disease can achieve a favorable prognosis.

BACKGROUND:The long-term patency rate of synthetic blood vessels remains a significant challenge that requires urgent attention.Enhancing the anticoagulant performance of small-caliber artificial blood vessels is crucial in ensuring their long-term efficacy.OBJECTIVE:To investigate the anticoagulation activity of polycaprolactone/low molecular weight fucoidan nanofibers with shell core structure and determine the effect on the activity of human umbilical vein endothelial cells.METHODS:Polycaprolactone nanofiber membranes and polycaprolactone/low molecular weight fucoidan nanofiber membranes with polycaprolactone as shell layer and low molecular weight fucoidan as core layer were prepared by emulsion electrospinning method(the mass ratio of low molecular weight fucoidan to polycaprolactone was 10％,25％,40％,and 55％,respectively).The morphology and structure of the fibers were characterized by scanning electron microscopy,fluorescence microscopy,and infrared spectroscopy.The mechanical strength of the fiber membranes was detected by tensile test.The loading rate and sustained release rate of low molecular weight fucoidan in the nanofibers were detected by 1,9-dimethylmethylene blue dye.The anticoagulant properties of the fiber membranes were verified by hemolysis test,dynamic coagulation test,plasma recalcification test,and platelet adhesion test.The five fiber membranes were co-cultured with human umbilical vein endothelial cells.The cell proliferation was detected by CCK-8 assay and the cell morphology was observed by fluorescence microscopy.RESULTS AND CONCLUSION:(1)Scanning electron microscope showed that the surface of polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane was smooth,the fiber diameter was uniform,and there was no obvious beaded structure.With the increase of low molecular weight brown algae polysaccharide content in the fiber membrane,the diameter of the fiber membrane increased and the maximum tensile stress decreased,but it still met the mechanical properties requirements of small-caliber artificial blood vessels.Fluorescence images and infrared spectra confirmed that low molecular weight brown algae polysaccharide was successfully loaded into polycaprolactone nanofiber membrane,and the low molecular weight brown algae polysaccharide loaded in each group of fiber membranes was released suddenly within 12 hours and released at a relatively low rate after 48 hours.(2)Compared with polycaprolactone nanofiber membrane,polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane had better anticoagulant activity,among which the group with a mass ratio of low molecular weight brown algae polysaccharide to polycaprolactone of 25％had the best anticoagulant effect.All five fiber membranes supported the growth and proliferation of human umbilical vein endothelial cells without affecting cell morphology and had no obvious cytotoxicity.(3)The results show that the polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane has good anticoagulant function,blood compatibility,and cell compatibility.

OBJECTIVE:Patients with osteoporotic vertebral compression fractures still have residual back pain after vertebral augmentation.The current research is characterized by limited sample size,complex confounding factors,and inconsistent research results.To gain a deeper understanding of this phenomenon,the aim of this study was to identify and evaluate the risk factors for residual back pain after surgery through a systematic review and meta-analysis.METHODS:A comprehensive search was conducted in CNKI,VIP,WanFang,CBMdisc,PubMed,The Cochrane Library,Embase,and Web of Science for case-control studies on residual back pain after vertebral body augmentation for osteoporotic vertebral compression fractures from database inception to July 2024.The search terms were a combination of subject terms and free terms.The basic information,patient characteristics,surgical-related indicators,and risk factors for surgical back pain of the included studies were extracted.After evaluating the bias risk of all included studies,a meta-analysis was conducted using Stata 14.0 software on the relevant indicators.RESULTS:(1)21 case-control studies with a total of 8 043 patients were included.Among them,965 patients developed back pain.The quality score of all 21 studies was ≥7.(2)The meta-analysis results showed that age(WMD=0.98,95％CI:0.40-1.56,P=0.010),bone mineral density(WMD=-0.28,95％CI:-0.34 to-0.21,P=0.000),the number of vertebral fractures(OR=3.50,95％CI:2.65-4.62,P=0.000),thoracolumbar fracture index(OR=3.65,95％CI:2.61-5.11,P=0.000),cement volume(OR=6.89,95％CI:2.62-18.17,P=0.000),and cement distribution(OR=2.38,95％CI:1.93-2.93,P=0.000)were risk factors for the development of back pain after vertebral body augmentation in patients with osteoporotic vertebral compression fractures.CONCLUSION:Current evidence indicates that age,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,bone cement injection volume,and the distribution of bone cement are risk factors for low back pain.Specifically,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,and non-uniform distribution of bone cement are identified as independent risk factors for low back pain.Patients exhibiting these high-risk factors require vigilant monitoring and prompt intervention to mitigate the occurrence of clinical low back pain,thereby enhancing patient outcomes and quality of life.

BACKGROUND:The long-term patency rate of synthetic blood vessels remains a significant challenge that requires urgent attention.Enhancing the anticoagulant performance of small-caliber artificial blood vessels is crucial in ensuring their long-term efficacy.OBJECTIVE:To investigate the anticoagulation activity of polycaprolactone/low molecular weight fucoidan nanofibers with shell core structure and determine the effect on the activity of human umbilical vein endothelial cells.METHODS:Polycaprolactone nanofiber membranes and polycaprolactone/low molecular weight fucoidan nanofiber membranes with polycaprolactone as shell layer and low molecular weight fucoidan as core layer were prepared by emulsion electrospinning method(the mass ratio of low molecular weight fucoidan to polycaprolactone was 10％,25％,40％,and 55％,respectively).The morphology and structure of the fibers were characterized by scanning electron microscopy,fluorescence microscopy,and infrared spectroscopy.The mechanical strength of the fiber membranes was detected by tensile test.The loading rate and sustained release rate of low molecular weight fucoidan in the nanofibers were detected by 1,9-dimethylmethylene blue dye.The anticoagulant properties of the fiber membranes were verified by hemolysis test,dynamic coagulation test,plasma recalcification test,and platelet adhesion test.The five fiber membranes were co-cultured with human umbilical vein endothelial cells.The cell proliferation was detected by CCK-8 assay and the cell morphology was observed by fluorescence microscopy.RESULTS AND CONCLUSION:(1)Scanning electron microscope showed that the surface of polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane was smooth,the fiber diameter was uniform,and there was no obvious beaded structure.With the increase of low molecular weight brown algae polysaccharide content in the fiber membrane,the diameter of the fiber membrane increased and the maximum tensile stress decreased,but it still met the mechanical properties requirements of small-caliber artificial blood vessels.Fluorescence images and infrared spectra confirmed that low molecular weight brown algae polysaccharide was successfully loaded into polycaprolactone nanofiber membrane,and the low molecular weight brown algae polysaccharide loaded in each group of fiber membranes was released suddenly within 12 hours and released at a relatively low rate after 48 hours.(2)Compared with polycaprolactone nanofiber membrane,polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane had better anticoagulant activity,among which the group with a mass ratio of low molecular weight brown algae polysaccharide to polycaprolactone of 25％had the best anticoagulant effect.All five fiber membranes supported the growth and proliferation of human umbilical vein endothelial cells without affecting cell morphology and had no obvious cytotoxicity.(3)The results show that the polycaprolactone/low molecular weight brown algae polysaccharide nanofiber membrane has good anticoagulant function,blood compatibility,and cell compatibility.

OBJECTIVE:Patients with osteoporotic vertebral compression fractures still have residual back pain after vertebral augmentation.The current research is characterized by limited sample size,complex confounding factors,and inconsistent research results.To gain a deeper understanding of this phenomenon,the aim of this study was to identify and evaluate the risk factors for residual back pain after surgery through a systematic review and meta-analysis.METHODS:A comprehensive search was conducted in CNKI,VIP,WanFang,CBMdisc,PubMed,The Cochrane Library,Embase,and Web of Science for case-control studies on residual back pain after vertebral body augmentation for osteoporotic vertebral compression fractures from database inception to July 2024.The search terms were a combination of subject terms and free terms.The basic information,patient characteristics,surgical-related indicators,and risk factors for surgical back pain of the included studies were extracted.After evaluating the bias risk of all included studies,a meta-analysis was conducted using Stata 14.0 software on the relevant indicators.RESULTS:(1)21 case-control studies with a total of 8 043 patients were included.Among them,965 patients developed back pain.The quality score of all 21 studies was ≥7.(2)The meta-analysis results showed that age(WMD=0.98,95％CI:0.40-1.56,P=0.010),bone mineral density(WMD=-0.28,95％CI:-0.34 to-0.21,P=0.000),the number of vertebral fractures(OR=3.50,95％CI:2.65-4.62,P=0.000),thoracolumbar fracture index(OR=3.65,95％CI:2.61-5.11,P=0.000),cement volume(OR=6.89,95％CI:2.62-18.17,P=0.000),and cement distribution(OR=2.38,95％CI:1.93-2.93,P=0.000)were risk factors for the development of back pain after vertebral body augmentation in patients with osteoporotic vertebral compression fractures.CONCLUSION:Current evidence indicates that age,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,bone cement injection volume,and the distribution of bone cement are risk factors for low back pain.Specifically,bone mineral density,the number of vertebral fractures,thoracolumbar fracture index,and non-uniform distribution of bone cement are identified as independent risk factors for low back pain.Patients exhibiting these high-risk factors require vigilant monitoring and prompt intervention to mitigate the occurrence of clinical low back pain,thereby enhancing patient outcomes and quality of life.

Objective:To explore the clinical characteristics, diagnosis and treatment strategies, and prognosis of pulmonary embolism (PE) complicating childhood rheumatic diseases.Methods:A retrospective case series study was performed on the demographic data, laboratory indicators, imaging features, treatment regimens, and follow-up data of 8 children with rheumatic diseases complicated by PE who were admitted to the Department of Rheumatology and Immunology, Capital Center for Children′s Health, Capital Medical University from January 2014 to October 2023.Results:Among the 8 children, there were 4 boys and 4 girls, with an age of 12.0 (7.5, 13.0) years. Among the primary diseases, there were 3 cases of systemic lupus erythematosus, 2 cases of Beh?et′s disease, 2 cases of Takayasu arteritis, and 1 case of antiphospholipid syndrome. All children developed PE during the active phase of the primary disease. PE was detected at the onset of the primary disease in 3 cases, and the median time from the diagnosis of the primary disease to the development of PE was 10.0 (6.0, 25.0) months in the remaining 5 cases. Fever was present in all 8 children, 4 cases were accompanied by chest tightness, dyspnea, etc., and 2 cases only presented with fever. Laboratory examinations revealed the following results: erythrocyte sedimentation rate was 42.0 (17.0, 78.0) mm/1 h, high-sensitivity C-reactive protein was 12.7 (2.6, 78.7) mg/L, white blood cell count was 9.6 (7.2, 18.7)×10 9/L; D-dimer was 2.3 (0.9, 6.2) mg/L; and hemoglobin was (109±16) g/L.Imaging examinations revealed that 5 cases had involvement of the bilateral lower pulmonary arteries, 5 cases had peripheral embolism, and 3 cases had central PE. Complications included 3 cases of deep vein thrombosis, 2 cases of intracranial venous sinus thrombosis, and 1 case of mild pulmonary hypertension.In terms of treatment, 7 cases received anticoagulation with heparin followed by warfarin. Immunomodulation was mainly based on glucocorticoids combined with immunosuppressants, and 4 cases were combined with biological agents. The follow-up time of 4.17 (1.75, 7.17) years, the time for complete absorption of PE was 10.5 (6.0, 18.0) months; all 8 children had no target events, with no recurrence or chronic thromboembolic pulmonary hypertension, and the pulmonary artery remodeling was good. Conclusions:PE complicating childhood rheumatic diseases is closely related to the activity of the primary disease. The clinical manifestations are insidious, with fever as the main symptom. Imaging examination is the key to diagnosis.Early adoption of heparin followed by warfarin anticoagulation and glucocorticoids combined with immunosuppressants and (or) biological agents to control the primary disease can achieve a favorable prognosis.

The study focuses on the concept of multifunctional traditional Chinese medicine (TCM) formulas and aims to evaluate the efficacy of the classical formula Xiaoyao San (逍遥散). Study employs the integrated evidence chain (Eff-iEC) method to organize, integrate, and evaluate its therapeutic efficacy in treating different diseases with the same therapy, and to investigate the feasibility of using Eff-iEC to evaluate the multifunctionality of TCM formulas. The evaluation covered Xiaoyao San's therapeutic effects on depression, premenstrual syndrome, chronic hepatitis, irritable bowel syndrome, dyspepsia, and menopausal syndrome. Concurrently, the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used for evaluation, and authoritative medical documents were incorporated to corroborate the recognition of Xiaoyao San within the medical community. Depression and menopausal syndrome received higher ratings than other conditions in the Eff-iEC, GRADE, and Medical Community Recognition assessments. The Eff-iEC evidence grade for Xiaoyao San was rated as "High" or above for chronic hepatitis, irritable bowel syndrome, dyspepsia, and menopausal syndrome. Premenstrual syndrome received a "Moderate ⁺" rating. The GRADE evidence level was "Low-〇〇⨁⨁" for depression, premenstrual syndrome, and chronic hepatitis; "Moderate-〇⨁⨁⨁" for dyspepsia and menopausal syndrome; and "Very Low-〇〇〇⨁" for irritable bowel syndrome. Depression and menopausal syndrome had the highest inclusion frequency, appearing in all 4 categories. Premenstrual syndrome, chronic hepatitis, and dyspepsia are not recommended in Western medical guidelines, but they are included in TCM guidelines, the China National Basic Medical Insurance Drug List, and the China National Essential Drug List. Irritable bowel syndrome appears only in the China National Basic Medical Insurance Drug List and China National Essential Drug List. The evaluation results obtained using the Eff-iEC method align with Medical Community Recognition, providing an objective and comprehensive assessment of Xiaoyao San's efficacy. The findings suggest that Xiaoyao San has strong evidence for treating depression and menopausal syndrome. However, further experimental and clinical trials are needed to assess its efficacy in treating premenstrual syndrome, chronic hepatitis, irritable bowel syndrome, and dyspepsia. These results support the clinical efficacy and rational use of Xiaoyao San, expand the application scope of the Eff-iEC method, and offer valuable insights and methodological references for the comparative evaluation of multifunctional TCM formulas.

Objective:To construct a prognostic risk model based on lactate metabolism-related genes screened using bioinformatics methods in renal cell carcinoma patients，and investigate the clinical prognosis and immune characteristics of renal cell carcinoma.Methods:Gene expression data and clinical information of patients with renal cell carcinoma were downloaded from the Cancer Genome Atlas-Kidney Renal Clear Cell Carcinoma（TCGA-KIRC）dataset. Lactate metabolism-related gene sets were obtained from the Gene Set Enrichment Analysis（GSEA）database. The R package DEseq2 was employed to identify differentially expressed genes associated with lactate metabolism within the TCGA-KIRC dataset. GO and KEGG enrichment analyses were performed using the clusterProfiler package. Prognosis-related genes were screened via univariate Cox regression analysis and the intersection with lactate metabolism-related differentially expressed genes was obtained. A risk model was constructed using LASSO regression followed by multivariate Cox regression analysis to calculate risk scores. This risk model was subsequently validated using the GSE29609 dataset. Patients were stratified into high-risk and low-risk groups based on the median risk score. The expression profiles of key immune molecule genes and immune checkpoint genes were compared between the two groups. Survival analysis curves for immune checkpoint genes were generated using the survival and survminer R packages. Differences in tumor mutation burden（TMB）between the high-risk and low-risk groups were assessed，and corresponding TMB survival analysis curves were plotted. Finally，the tumor immune dysfunction and exclusion（TIDE）algorithm was used to evaluate disparities in immunotherapy response potential between the two risk groups.Results:An optimal prognostic risk model incorporating seven lactate metabolism- and prognosis-related genes（ LDHD，PER2，ACADM，FLI1，LIPA，TCIRG1，SLC25A4）was constructed and successfully validated in the GSE29609 dataset. Univariate Cox regression analysis revealed that a high-risk score was significantly associated with poor prognosis（ HR=2.915，95% CI：2.451-3.470， P<0.001）. Multivariate Cox regression analysis confirmed that this risk model could serve as an independent prognostic factor for patients with renal cell carcinoma（ HR=2.231，95% CI：1.829-2.722， P<0.001）. Patients in the high-risk group exhibited significantly worse outcomes compared to the low-risk group，regardless of whether they had early-stage or advanced-stage renal cell carcinoma（both P<0.001）. Analyses related to the immune microenvironment indicated an upregulated immunosuppressive phenotype in the high-risk group. Furthermore，the TMB was significantly higher in the high-risk group than in the low-risk group（ P=0.032），and patients within the high-risk group exhibiting higher TMB levels demonstrated even poorer survival（ P<0.001）. Finally，the TIDE score was significantly elevated in the high-risk group in comparison to the low-risk group（ P<0.001）. Conclusions:The risk model based on lactate metabolism-related genes constructed in this study can guide the prognosis of renal cell carcinoma. Patients in the high-risk group are more prone to immune escape and formation of an inhibitory immune microenvironment，leading to worse prognoses. This risk model may serve as a biomarker for predicting immunotherapy response.

Objective:To evaluate the safety and effectiveness of fuzuloparib for the treatment of ovarian epithelial cancer patients in the real world setting.Methods:A retrospective analysis was conducted on the baseline data of 4 620 ovarian cancer patients who had received fuzuloparib monotherapy or combination therapy. Another 224 ovarian cancer patients who were willing to receive fuzuloparib monotherapy or combination therapy were prospectively enrolled, and their baseline characteristics, drug effectiveness, and safety data were analyzed.Results:(1) Among the 4 620 patients in the retrospective cohort, the median age of patients was 60 years; tumor types: 89.8% (4 149/4 620) had ovarian cancer. Among patients with clearly documented information, the vast majority had a histological type of serous carcinoma (82.9%, 3 770/4 546) and International Federation of Gynecology and Obstetrics (FIGO) staging of Ⅲ-Ⅳ (90.9%, 1 537/1 691). (2) Among the 224 patients in the prospective cohort, the median age of patients was 57 years; tumor types: 83.9% (188/224) had ovarian cancer. Among patients with clearly documented records, the predominant pathologic type was serous carcinoma (91.9%, 193/210), and FIGO stage was Ⅲ-Ⅳ in 79.9% (139/174). (3) Among the 224 prospective patients: 84 patients received first-line fluzoparib maintenance therapy, 92 patients received fluzoparib maintenance therapy after platinum-sensitive recurrence, 23 patients received direct fluzoparib treatment after platinum-sensitive recurrence, 19 patients received direct fluzoparib treatment after platinum-resistant recurrence. The median follow-up durations were 8.5, 8.7, 7.9, and 6.7 months, respectively. The median durations of fluzoparib treatment were 6.7, 4.8, 3.1, and 1.9 months, respectively. The median progression-free survival (PFS) times were not reached during follow-up, 12.6 months, not reached during follow-up, and 4.8 months, respectively. The 1-year PFS rates were 84.1%, 55.0%, 69.8%, and 45.5%, respectively. The remaining 6 patients received other fluzoparib regimens. (4) Among the 224 patients in the prospective dataset, 205 had safety data recorded. Of these, 127 patients (62.0%, 127/205) experienced treatment-related adverse events, with common events including anemia (24.4%, 50/205), thrombocytopenia (21.0%, 43/205), and leukopenia (19.5%, 40/205). Among the 205 patients, 43 (21.0%, 43/205) experienced grade 3 or higher treatment-related adverse events, with common events including anemia (8.3%, 17/205) and thrombocytopenia (8.3%, 17/205).Conclusions:The effectiveness of fuzuloparib in clinical application is generally consistent with other drugs in the same class, with good safety. This study provids new clinical evidence for the treatment of ovarian cancer with fuzuloparib.

Objective:To analyze the clinical characteristics of anti-melanoma differentiation associated gene 5 (MDA5) antibody-positive juvenile dermatomyositis (JDM) patients.Methods:A retrospective case-control study was conducted. The positive group included 18 children with anti-MDA5 antibody-positive JDM who were admitted to the Department of Rheumatology and Immunology at Capital Center for Children′s Health with Capital Medical University between January 2016 and January 2023. Another 36 children with anti-MDA5 antibody-negative JDM hospitalized during the same period were enrolled as the negative group. Based on the extent of pulmonary involvement and pulmonary CT scores, the MDA5-positive group was further divided into severe pulmonary involvement and non-severe pulmonary involvement subgroups. Chi-square test and Kruskal-Wallis test were used to compare clinical features, laboratory test results between groups.Results:Among the 18 patients in the MDA5-positive group, 7 were male and 11 were female, with an age of onset of 5.0 (2.6, 9.4) years and disease duration of 6.0 (4.0, 9.3) months. The MDA5-negative group included 36 cases (14 male, 22 female), with an age of onset of 4.9 (2.0, 7.0) years and disease duration of 5.0 (1.8, 7.0) months. The MDA5-positive group exhibited significantly higher rates of arthritis, skin ulcers, and interstitial lung disease (ILD), along with elevated serum ferritin (SF) and erythrocyte sedimentation rate levels compared to the MDA5-negative group (9/18 vs. 11% (4/36), 6/18 vs. 3% (1/36), 16/18 vs. 33% (12/36), 327 (141, 518) vs. 131 (68, 257) μg/L, 17.5 (12.5, 26.8) vs. 11.0 (5.0, 13.0) mm/1 h, χ2=7.92, 7.41, 14.84, Z=2.50, 2.87, all P<0.05). Conversely, the MDA5-positive group had lower rates of muscle weakness and lower creatine kinase levels (5/18 vs. 75% (27/36), 58.5 (49.3, 97.5) vs. 225.0 (68.0, 695.5) U/L, χ2=11.08, Z=-2.94, both P<0.05). Severe pulmonary involvement 6 cases and non-severe pulmonary involvement subgroups 12 cases. Among the MDA5-positive patients, those in the severe pulmonary involvement subgroup had an older age at onset and higher rates of muscle weakness as well as hydroxybutyrate dehydrogenase (HBDH), lactate dehydrogenase (LDH), SF, and Krebs von den Lungen-6 (KL-6) compared to the non-severe subgroup (all P<0.05). In the MDA5-positive group, 17 patients improved after treatment with glucocorticoids combined with immunosuppressants, while One died due to rapidly progressive ILD. Conclusions:Anti-MDA5 antibody-positive JDM is characterized by typical skin rashes, a high incidence of arthritis and skin ulcers, relatively mild muscle involvement, but is prone to ILD. Among MDA5-positive patients, those with older age at onset, muscle involvement (manifested as muscle weakness and elevated muscle enzymes (LDH, HBDH)), or significantly elevated KL-6 and SF levels are more likely to develop severe pulmonary complications.