Objective To evaluate the correlation between alterations in DNase1 and DNase1L3 enzyme activities and impairment of NET degradation in patients with sporadic SLE, and to investigate the underlying mechanism. Methods 46 sporadic SLE patients and 30 age- and sex-matched healthy individuals were recruited. Serum levels of DNase1, DNase1L3 and corresponding autoantibodies were detected by ELISA. DNase1 and DNase1L3 were isolated by immunoprecipitation; NETs and enzyme degradation activities were detected using a modified immunofluorescence. DNase1L3 secretion by PBMCs was analyzed by ELISPOT, Western blotting and reverse transcription PCR. Results Levels of H3-dsDNA and Ela-dsDNA complexes were significantly elevated in SLE patients. LDGs in SLE population was significantly higher than in the control group, and LDGs was positively correlated with H3-dsDNA and Ela-dsDNA NETs complexes. The ability of SLE patients to degrade NET in vitro was significantly lower than that of the control group. Degradation experiments of DNase1 and DNase1L3 in different proportions showed that the decrease in DNase1L3 activity was the primary contributor to the elevated NET residue level. The concentration of DNase1L3 autoantibodies in SLE patients was significantly elevated compared to the control group. In addition, the capacity of PBMCs to secrete DNase1L3 was significantly lower in the SLE patients compared to the control group. Conclusion Decreased secretion of DNase1L3 and the presence of relevant autoantibodies notably impede NET degradation in patients with SLE, offering new directions for the monitoring and treatment of SLE patients.
Humans ; Autoantibodies ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Extracellular Traps ; Lupus Erythematosus, Systemic

Autoantibodies are important biomarkers of autoimmune diseases and crucial for disease diagnosis, differential diagnosis, and the evaluation of disease activity and prognosis. Specifying the requirement of quality control for detecting autoantibodies is essential for accurately reporting relevant results. In 2023, National Clinical Research Center for Dermatologic and Immunologic Diseases (Peking Union Medical College Hospital), Experimental Diagnosis Research Committee, Rheumatology and Immunology Physicians Committee of Chinese Medical Doctor Association, Autoantibodies Detection Committee, Chinese Rheumatism Data Center invited relevant clinical and laboratory experts to develop the current consensus based on the national standards, the industry guidelines, the national situation, and the experience of quality control regarding autoantibody detection. This consensus aims to standardize the quality control of autoantibody detection in relevant laboratories in China.
Humans ; Autoantibodies ; Consensus ; Autoimmune Diseases/diagnosis* ; Quality Control ; Reference Standards

Cold agglutinins(CA),autoantibodies against the antigen I or i on the surface of red blood cells,are mainly of IgM class,and the majority have κ light chains.They can lead to red blood cell agglutination at decreased body temperature and are usually associated with infections,drug reactions,autoimmune diseases,and hematological malignancies.However,solid tumors with CA are rare.We reported two cases of CA in the peripheral blood of patients with solid tumors.Peripheral complete blood cell count of the patients at admission showed reduced erythrocyte count and hematocrit,mismatching between erythrocyte count and hemoglobin,abnormally elevated levels of mean corpuscular hemoglobin and mean cell hemoglobin concentration.Peripheral blood smear showed erythrocyte aggregation.After the sample was preheated at 37 ℃ for 30 min,the reversibility of red blood cell aggregation was observed,and the erythrocyte parameters were corrected.
Humans ; Autoantibodies/isolation & purification* ; Female ; Breast Neoplasms/immunology* ; Ovarian Neoplasms/immunology*

Objective: To summarize the clinical characteristics of tumour necrosis factor receptor-associated periodic syndrome (TRAPS) in children. Methods: The clinical manifestations, laboratory tests, genetic testing and follow-up of 10 children with TRAPS from May 2011 to May 2021 in 6 hospitals in China were retrospectively analyzed. Results: Among the 10 patients with TRAPS, including 8 boys and 2 girls. The age of onset was 2 (1, 5) years, the age of diagnosis was (8±4) years, and the time from onset to diagnosis was 3 (1, 7) years. A total of 7 types of TNFRSF1A gene variants were detected, including 5 paternal variations, 1 maternal variation and 4 de novo variations. Six children had a family history of related diseases. Clinical manifestations included recurrent fever in 10 cases, rash in 4 cases, abdominal pain in 6 cases, joint involvement in 6 cases, periorbital edema in 1 case, and myalgia in 4 cases. Two patients had hematological system involvement. The erythrocyte sedimentation rate and C-reactive protein were significantly increased in 10 cases. All patients were negative for autoantibodies. In the course of treatment, 5 cases were treated with glucocorticoids, 7 cases with immunosuppressants, and 7 cases with biological agents. Conclusions: TRAPS is clinically characterized by recurrent fever accompanied by joint, gastrointestinal, skin, and muscle involvement. Inflammatory markers are elevated, and autoantibodies are mostly negative. Treatment mainly involves glucocorticoids, immunosuppressants, and biological agents.
Male ; Child ; Female ; Humans ; Child, Preschool ; Receptors, Tumor Necrosis Factor, Type I/genetics* ; Retrospective Studies ; Hereditary Autoinflammatory Diseases/drug therapy* ; Glucocorticoids/therapeutic use* ; Biological Factors/therapeutic use* ; Immunosuppressive Agents/therapeutic use* ; Autoantibodies ; Familial Mediterranean Fever/diagnosis* ; Mutation

OBJECTIVES: To study the clinical features of children with autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A). METHODS: A retrospective analysis was performed on the medical data of 34 children with GFAP-A who attended the Department of Neurology, Children's Hospital of Chongqing Medical University, from January 2020 to February 2022. The medical data included clinical manifestations, cerebrospinal fluid features, imaging examination results, treatment, and prognosis. RESULTS: The median age of onset was 8.4 (range 1.9-14.9) years for the 34 children with GFAP-A. The main clinical manifestations included headache (50%, 17/34), fever (47%, 16/34), visual impairment (47%, 16/34), and disturbance of consciousness (44%, 15/34). Abnormal cerebrospinal fluid results were observed in 19 children (56%, 19/34), among whom 8 children had positive autoantibody. The children with overlap syndrome had significantly higher recurrence rate and rate of use of immunosuppressant than those without overlap syndrome (P<0.05). About 77% (24/31) of the children had good response to immunotherapy, and only 1 child had poor prognosis. CONCLUSIONS Children with GFAP-A often have non-specific clinical symptoms and show good response to immunotherapy. Children with overlap syndrome have a high recurrence rate, and early application of immunosuppressants may help to prevent recurrence and alleviate symptoms.
Adolescent ; Child ; Child, Preschool ; Humans ; Infant ; Astrocytes/metabolism* ; Autoantibodies/metabolism* ; Glial Fibrillary Acidic Protein/metabolism* ; Prognosis ; Retrospective Studies ; Autoimmune Diseases/metabolism*

OBJECTIVES: Programmed death 1 (PD-1) associated fulminant type 1 diabetes (PFD) is a rare acute and critical in internal medicine, and its clinical characteristics are still unclear. This study aims to analyze the clinical characteristics of PFD patients to improve clinical diagnosis and treatment. METHODS: We retrospectively analyzed the clinical data of 10 patients with PFD admitted to the Second Xiangya Hospital of Central South University, combined with the data of 66 patients reported in the relevant literature, analyzed and summarized their clinical and immunological characteristics, and compared the patients with PFD with different islet autoantibody status. RESULTS: Combined with our hospital and literature data, a total of 76 patients with PFD were reported, with the age of (60.9±12.1) years old, 60.0% male and body mass index of (22.1±5.2) kg/m2. In 76 patients, the most common tumors were lung cancer (43.4%) and melanoma (22.4%). Among PD-1 inhibitors, the most common drugs are nivolumab (37.5%) and pembrolizumab (38.9%). 82.2% of PFD patients developed diabetes ketoacidosis. The median onset time from PD-1 related inhibitor treatment to hyperglycemia was 95 (36.0, 164.5) d, and the median treatment cycle before the onset of diabetes was 6 (2.3, 8.0) cycles. 26% (19/73) of PFD patients had positive islet autoantibodies, and the proportion of ketoacidosis in the positive group was significantly higher than that in the negative group (100.0% vs 75.0%, P<0.05). The onset time and infusion times of diabetes after PD-1 inhibitor treatment in the autoantibody positive group were significantly lower than those in the autoantibody negative group (28.5 d vs 120.0 d; 2 cycles vs 7 cycles, both P<0.001). CONCLUSIONS After initiation of tumor immunotherapy, it is necessary to be alert to the occurrence of adverse reactions of PFD, and the onset of PFD with islet autoantibody positive is faster and more serious than that of patients with autoantibodies negative. Detection of islet autoantibodies and blood glucose before and after treatment with PD-1 inhibitors is of great value for early warning and prediction of PFD.
Humans ; Male ; Middle Aged ; Aged ; Female ; Diabetes Mellitus, Type 1 ; Programmed Cell Death 1 Receptor ; Immune Checkpoint Inhibitors/therapeutic use* ; Retrospective Studies ; Ketosis ; Autoantibodies

The extracellular domain (p75ECD) of p75 neurotrophin receptor (p75NTR) antagonizes Aβ neurotoxicity and promotes Aβ clearance in Alzheimer's disease (AD). The impaired shedding of p75ECD is a key pathological process in AD, but its regulatory mechanism is largely unknown. This study was designed to investigate the presence and alterations of naturally-occurring autoantibodies against p75ECD (p75ECD-NAbs) in AD patients and their effects on AD pathology. We found that the cerebrospinal fluid (CSF) level of p75ECD-NAbs was increased in AD, and negatively associated with the CSF levels of p75ECD. Transgenic AD mice actively immunized with p75ECD showed a lower level of p75ECD and more severe AD pathology in the brain, as well as worse cognitive functions than the control groups, which were immunized with Re-p75ECD (the reverse sequence of p75ECD) and phosphate-buffered saline, respectively. These findings demonstrate the impact of p75ECD-NAbs on p75NTR/p75ECD imbalance, providing a novel insight into the role of autoimmunity and p75NTR in AD.
Mice ; Animals ; Alzheimer Disease/pathology* ; Receptor, Nerve Growth Factor ; Amyloid beta-Peptides ; Autoantibodies ; Mice, Transgenic

Objective To investigate the clinical significance of thrombospondin type 1 domain-containing 7A (THSD7A) and neural epidermal growth factor-like 1 protein (NELL1) in phospholipase A2 receptor (PLA2R)-negative membranous nephropathy (MN). Methods A total of 116 PLA2R-negative MN patients treated in Hangzhou TCM Hospital Affiliated to Zhejiang Chinese Medical University from 2014 to 2021 were enrolled in this study.Immunohistochemistry was employed to detect THSD7A and NELL1 in the renal tissue.The pathological characteristics,treatment,and prognosis were compared between positive and negative groups. Results The 116 PLA2R-negative MN patients included 23 THSD7A-positive patients and 9 NELL1-positive patients.One patient was tested positive for both proteins.The THSD7A-positive group showed higher positive rate of IgG4 (P=0.010),more obvious glomerular basement membrane (GBM) thickening (P=0.034),and higher proportion of stage Ⅱ MN and lower proportion of stage I MN (P=0.002) than the THSD7A-negative group.The NELL1-positive group had lower positive rates of C1q and IgG2 (P=0.029,P=0.001),less obvious GBM thickening (P<0.001),more extensive inflammatory cell infiltration (P=0.033),lower proportion of deposits on multi-locations (P=0.001),and lower proportion of atypical MN (P=0.010) than the NELL1-negative group.One patient with THSD7A-positive MN was diagnosed with colon cancer,while none of the NELL1-positive patients had malignancy.Survival analysis suggested that THSD7A-positive MN had worse composite remission (either complete remission or partial remission) of nephrotic syndrome than the negative group (P=0.016),whereas NELL1-positive MN exhibited better composite remission of nephrotic syndrome than the negative group (P=0.015).The MN patients only positive for NELL1 showed better composite remission of nephrotic syndrome than the MN patients only positive for THSD7A (P<0.001). Conclusions THSD7A- and NELL1-positive MN is more likely to be primary MN,and there is no significant malignancy indication.However,it might have a predictive value for the prognosis of MN.
Humans ; Autoantibodies ; Clinical Relevance ; Colonic Neoplasms ; EGF Family of Proteins ; Glomerulonephritis, Membranous/diagnosis* ; Nephrotic Syndrome ; Receptors, Phospholipase A2/metabolism* ; Thrombospondins/metabolism*

Both anti-glomerular basement membrane (GBM) disease and the anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are common causes of pulmonary-renal syndrome. Organizing pneumonia (OP), a special pattern of interstitial lung disease, is extremely rare either in AAV or anti-GBM disease. We report an old woman presented with OP on a background of co-presentation with both ANCA and anti-GBM antibodies.
Female ; Humans ; Antibodies, Antineutrophil Cytoplasmic ; Organizing Pneumonia ; Autoantibodies ; Glomerulonephritis ; Anti-Glomerular Basement Membrane Disease ; Pneumonia ; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis/complications*

Standardisation and harmonisation of the detection of autoantibodies is important for the clinical application of autoantibodies. However, achieving complete standardisation is difficult and involves several challenges due to the complexity and particularity of autoantibody detection. Harmonisation is feasible and valued, but it involves all aspects and processes of autoantibody detection. Based on the consensus and practice of the clinical application of autoantibody detection in recent years, we discuss harmonisation in this review.
Humans ; Autoantibodies ; Reference Standards