Objective:This study aims to provide insights into the clinical features of anti-melanoma differentiation-associated protein-5(MDA5)-positive dermatomyositis (MDA5-DM) patients with fatal outcomes, leveraging pathogenic microbiota metagenomic analysis, to guide the clinical assessment and treatment choices.Methods:From January 2020 to August 2023, deceased patients diagnosed with MDA5-DM were identified at the Department of Rheumatology and Immunology, the Second Affiliated Hospital of Xi ′an Jiaotong University. Clinical data were retrospectively collected and analyzed using Mann Whitney U test and Fisher ′s exact test to summarize risk factors and treatment assessment for MDA5-DM patients with fatal outcomes. Results:①The proportion of male patients was higher than females among MDA5-DM patients with fatal outcomes, which differed from the incidence pattern, possibly associated with smoking and gender proportions (6/11 vs. 0/7, P=0.037). ②94%(17/18) patients presented initially with elevated ferritin levels [(1 350±942)ng/ml] and CRP [(47±36)mg/L]. ③All patients (18/18) exhibited early involvement of the upper lung lobes, including multiple nodules in 9/18, ground-glass opacities in 5/18, and solitary nodules in 4/18. ④Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid was negative in 4/16 cases, with cytomegalovirus and pneumocystis jirovecii being the most commonly detected pathogens in 5/16 cases each. ⑤89%(16/18) of patients continued to have lymphocyte counts persistently <0.5×10 9/L irrespective of treatment. Conclusion:Smoking may have adverse effects on male MDA5 patients. Early involvement of the upper lobe of the lungs is more common in MDA5 antibody positive deaths, and persistent lymphocyte depletion is an important factor in poor response. Enhancing mNGS analysis of bronchoalveolar lavage fluid and vigilance towards cytomegalovirusand Pneumocystis jirovecii could provide valuable clinical guidance.

Objective:This study aims to provide insights into the clinical features of anti-melanoma differentiation-associated protein-5(MDA5)-positive dermatomyositis (MDA5-DM) patients with fatal outcomes, leveraging pathogenic microbiota metagenomic analysis, to guide the clinical assessment and treatment choices.Methods:From January 2020 to August 2023, deceased patients diagnosed with MDA5-DM were identified at the Department of Rheumatology and Immunology, the Second Affiliated Hospital of Xi ′an Jiaotong University. Clinical data were retrospectively collected and analyzed using Mann Whitney U test and Fisher ′s exact test to summarize risk factors and treatment assessment for MDA5-DM patients with fatal outcomes. Results:①The proportion of male patients was higher than females among MDA5-DM patients with fatal outcomes, which differed from the incidence pattern, possibly associated with smoking and gender proportions (6/11 vs. 0/7, P=0.037). ②94%(17/18) patients presented initially with elevated ferritin levels [(1 350±942)ng/ml] and CRP [(47±36)mg/L]. ③All patients (18/18) exhibited early involvement of the upper lung lobes, including multiple nodules in 9/18, ground-glass opacities in 5/18, and solitary nodules in 4/18. ④Metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid was negative in 4/16 cases, with cytomegalovirus and pneumocystis jirovecii being the most commonly detected pathogens in 5/16 cases each. ⑤89%(16/18) of patients continued to have lymphocyte counts persistently <0.5×10 9/L irrespective of treatment. Conclusion:Smoking may have adverse effects on male MDA5 patients. Early involvement of the upper lobe of the lungs is more common in MDA5 antibody positive deaths, and persistent lymphocyte depletion is an important factor in poor response. Enhancing mNGS analysis of bronchoalveolar lavage fluid and vigilance towards cytomegalovirusand Pneumocystis jirovecii could provide valuable clinical guidance.

Objective To study the role of natural antiox-LDL subclass IgM antibodies in formation of atherclerosis.Methods The macrophages from mice were divded into LDL group,Cuox-LDL group and control group.The macrophages in LDL group and Cuox-LDL group were precultured with LDL and Cuox-LDL.Adhesion experiment was performed in control group.3A6,5G8 and 2H7 were incubated.The macrophages were divided into 3A6 group,5G8 group and 2H7 group.Adhesion experiment was performed by adding the pretreated 125I Cuox-LDL.The binding parameters of macrophages and 125I Cuox-LDL in different groups were recorded.Foam cells were analyzed by cell lipid analysis with oil red O staining.Results The bound 125I Cuox-LDL level was significantly lower in Cuox-LDL group than in control group and LDL group (P＜0.01).No significant difference was found in bound 125I Cuox-LDL level between 5G3 group and 2H7 group (P＞0.05).The bound 125I Cuox-LDL level was significantly lower in 3A6 group than in control group,5G8 group and 2H7 group (P＜0.01).Oil red O staining showed no oil drop in macrophages,but a small number of oil drops in 3A6 group and a large number of oil drops in control group.The cholesterol and TG in macrophages reduced 45％ and the TG reduced 170％ in 3A6 group,which were significantly lower than those in control group (P＜0.01).Conclusion Antiox-LDL IgM subclass antibody 3A6 can effectively prevent the binding of unactivated macrophages to ox-LDL,reduce the occurrence and progression of atherosclerosis.