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

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

Objective: To investigate the misdiagnosis of area postrema syndrome (APS) manifesting as intractable nausea, vomiting and hiccups in neuromyelitis optic spectrum disease (NMOSD) and reduce the risk of misdiagnosis. Methods: We retrospectively analyzed data from NMOSD patients attending the Department of Neurology at the First Medical Center of PLA General Hospital between January 2019 and July 2021. SPSS25.0 was then used to analyze the manifestations, misdiagnosis, and mistreatment of APS. Results: A total of 207 patients with NMOSD were included, including 21 males and 186 females. The mean age of onset was 39±15 years (range: 5-72 years). The proportion of patients who were positive for serum aquaporin 4 antibody was 82.6% (171/207). In total, 35.7% (74/207) of the NMOSD patients experienced APS during the disease course; of these patients, 70.3% (52/74) had APS as the first symptom and 29.7% (22/74) had APS as a secondary symptom. The misdiagnosis rates for these conditions were 90.4% (47/52) and 50.0% (11/22), respectively. As the first symptom, 19.2% (10/52) of patients during APS presented only with intractable nausea, vomiting and hiccups; 80.8% (42/52) of patients experienced other neurological symptoms. The Departments of Gastroenterology and General Medicine were the departments that most frequently made the first diagnosis of APS, accounting for 54.1% and 17.6% of patients, respectively. The most common misdiagnoses related to diseases of the digestive system and the median duration of misdiagnosis was 37 days. Conclusions: APS is a common symptom of NMOSD and is associated with a high rate of misdiagnosis. Other concomitant symptoms often occur with APS. Gaining an increased awareness of this disease/syndrome, obtaining a detailed patient history, and performing physical examinations are essential if we are to reduce and avoid misdiagnosis.
Male ; Female ; Humans ; Child, Preschool ; Child ; Adolescent ; Young Adult ; Adult ; Middle Aged ; Aged ; Neuromyelitis Optica/diagnosis* ; Area Postrema ; Retrospective Studies ; Hiccup/complications* ; Vomiting/etiology* ; Nausea/etiology* ; Inflammation ; Syndrome ; Autoantibodies ; Diagnostic Errors ; Aquaporin 4

The patient was a 55-year-old man who was admitted to hospital with "progressive myalgia and weakness for 4 months, and exacerbated for 1 month". Four months ago, he presented with persistent shoulder girdle myalgia and elevated creatine kinase (CK) at routine physical examination, which fluctuated from 1 271 to 2 963 U/L after discontinuation of statin treatment. Progressive myalgia and weakness worsened seriously to breath-holding and profuse sweating 1 month ago. The patient was post-operative for renal cancer, had previous diabetes mellitus and coronary artery disease medical history, had a stent implanted by percutaneous coronary intervention and was on long-term medication with aspirin, atorvastatin and metoprolol. Neurological examination showed pressure pain in the scapularis and pelvic girdle muscles, and V- grade muscle strength in the proximal extremities. Strongly positive of anti-HMGCR antibody was detected. Muscle magnetic resonance imaging (MRI) T2-weighted image and short time inversion recovery sequences (STIR) showed high signals in the right vastus lateralis and semimembranosus muscles. There was a small amount of myofibrillar degeneration and necrosis, CD4 positive inflammatory cells around the vessels and among myofibrils, MHC-Ⅰ infiltration, and multifocal lamellar deposition of C5b9 in non-necrotic myofibrils of the right quadriceps muscle pathological manifestation. According to the clinical manifestation, imageological change, increased CK, blood specific anti-HMGCR antibody and biopsy pathological immune-mediated evidence, the diagnosis of anti-HMGCR immune-mediated necrotizing myopathy was unequivocal. Methylprednisolone was administrated as 48 mg daily orally, and was reduced to medication discontinuation gradually. The patient's complaint of myalgia and breathlessness completely disappeared after 2 weeks, the weakness relief with no residual clinical symptoms 2 months later. Follow-up to date, there was no myalgia or weakness with slightly increasing CK rechecked. The case was a classical anti-HMGCR-IMNM without swallowing difficulties, joint symptoms, rash, lung symptoms, gastrointestinal symptoms, heart failure and Raynaud's phenomenon. The other clinical characters of the disease included CK as mean levels >10 times of upper limit of normal, active myogenic damage in electromyography, predominant edema and steatosis of gluteus and external rotator groups in T2WI and/or STIR at advanced disease phase except axial muscles. The symptoms may occasionally improve with discontinuation of statins, but glucocorticoids are usually required, and other treatments include a variety of immunosuppressive therapies such as methotrexate, rituximab and intravenous gammaglobulin.
Male ; Humans ; Middle Aged ; Autoantibodies ; Myositis/diagnosis* ; Autoimmune Diseases ; Muscle, Skeletal/pathology* ; Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use* ; Necrosis/pathology* ; Muscular Diseases/drug therapy*

OBJECTIVE: To evaluate the value of pharmacogenetic testing for improving the efficacy and safety of treatment with cyclosporine, tacrolimus, and cyclophosphamide (CTX) for PLA2R-related membranous nephropathy and for determing individualized and precise treatment plans for the patients. METHODS: A total of 63 patients with PLA2R-related membranous nephropathy hospitalized in the Department of Nephrology at our hospital from January, 2019 to October, 2021 were enrolled in this study. Thirty-three of the patients underwent pharmacogenetic testing before taking the immunosuppressive drugs selected based on the results of genetic screening for sensitive targets, and the other 30 patients were empirically given immunosuppressive drugs according to the guidelines (control group). The clinical efficacy and adverse effects of the immunosuppressive drugs were analyzed for all the patients. The two groups of patients were compared for demographic and biochemical parameters including 24-h urine protein, serum albumin, renal function, and serum anti-phospholipase A2 receptor antibody both before and at 3 months after the beginning of the treatment. RESULTS: Among the 33 patients undergoing pharmacogenetic testing, 51.5% showed a GG genotype for cyclosporine, and 61.6% had an AG genotype for tacrolimus; for CTX, 51.5% of the patients showed a homozygous deletion and 63.6% had an AA genotype. After treatment for 3 months, serum anti-phospholipase A2 receptor antibody, 24-h urine protein, and serum albumin levels were significantly improved in pharmacogenetic testing group as compared with the control group (P < 0.05). CONCLUSION Individualized and precise administration of immunosuppressive drugs based on pharmacogenetic testing better controls proteinuria and serum antiphospholipase A2 receptor antibodies and increases serum albumin level in patients with PLA2R-related membranous nephropathy.
Humans ; Autoantibodies ; Cyclosporine/therapeutic use* ; Glomerulonephritis, Membranous/diagnosis* ; Homozygote ; Immunosuppressive Agents/therapeutic use* ; Pharmacogenomic Testing ; Receptors, Phospholipase A2 ; Sequence Deletion ; Serum Albumin ; Tacrolimus/therapeutic use*

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