Antigenic cartography using sera from sequence-confirmed SARS-CoV-2 variants of concern infections reveals antigenic divergence of Omicron

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Cholinergic hyperactivity in patients with myasthenia gravis with MuSK antibodies: A neurophysiological study

ObjectivePatients with myasthenia gravis associated with muscle-specific tyrosine kinase antibodies (MuSK-MG) often manifest signs of cholinergic hyperactivity with standard doses of acetylcholinesterase inhibitors (AChE-Is). Aim of the study was to investigate whether repetitive compound muscle action potential (R-CMAP), the neurophysiological correlate of cholinergic hyperactivity, was present in MuSK-MG irrespective of AChE-I treatment.MethodsPatients with confirmed diagnosis of MuSK-MG were consecutively enrolled during follow-up visits, from January 2019 to April 2020. All these subjects underwent the same neurophysiological protocol, including motor nerve conduction studies and repetitive nerve stimulation. In patients taking pyridostigmine, neurophysiological testing was performed at least 12 hours after the last dose. For comparison, the presence of R-CMAP was investigated in 20 consecutive acetylcholine receptor antibody positive myasthenia gravis (AChR-MG) patients.ResultsWe enrolled 25 MuSK-MG patients (20 females), aged 16–79 years at the study time, with disease duration ranging 0.6–48.8 years (median: 17.7 years). R-CMAP was detected in 12/25 (48%) MuSK-MG cases and in none of the AChR-MG controls (p = 0.0003). In the MuSK-MG population, a history of muscle cramps and fasciculations, during low-dose pyridostigmine therapy, was significantly more frequent in R-CMAP positive than in R-CMAP negative patients (100% vs 31%, p = 0.001). At the time of the study, the proportion of patients still symptomatic for MG was higher among R-CMAP positive cases (92% vs 23%, p = 0.0005).ConclusionsCholinergic hyperactivity is a relatively common finding in MuSK-MG patients, independent of AChE-I treatment, and may constitute an intrinsic feature of the disease.SignificanceR-CMAP detection can represent a useful diagnostic clue for MuSK-MG and predicts poor tolerance to AChE-Is.     

Searching for Serum Antibodies to Neuronal Proteins in Patients With Myalgic Encephalopathy/Chronic Fatigue Syndrome

PurposeA role for the immune system in causing myalgic encephalopathy/chronic fatigue syndrome (ME/CFS) is long suspected, but few studies have looked for specific autoantibodies that might contribute to the symptoms. Our aim was to look for evidence of antibodies to neuronal proteins in patients with ME/CSF.MethodsSera samples from 50 patients and 50 healthy individuals were sent coded to the Neuroimmunology Laboratory in Oxford. Screening for antibody binding to neuronal tissue was performed on brain tissue and neuronal cultures. Specific serum antibodies were assessed by antigen-specific cell-based assays and radioimmunoassays. After antibody testing, the associations between seropositive status and clinical data were investigated.FindingsOverall, 8 patients and 11 participants were found to have some serum immunoreactivity toward neuronal or neuromuscular junction proteins, but only 1 patient and 2 participants had specific serum antibodies. Nevertheless, seropositive status in patients with ME was associated with shorter duration since onset and a more severe disease.ImplicationsThe results indicate no overall increased frequency of antibodies to neuronal proteins in ME/CSF and no evidence of a specific antibody that might be causative or contribute to clinical features in patients. However, the association of seropositive status with shorter duration of disease and more severe symptoms suggests a possible role of antibodies at onset in some patients and should be the focus of future studies.     

Dual Monoclonal Antibody Therapy in Patients With Systemic AL Amyloidosis and Cardiac Involvement

BackgroundSystemic AL amyloidosis (AL) is a rare disease in which clonal immunoglobulin light chains produced by monoclonal plasma cells circulate and misfold, resulting in direct toxicity and fibrillar deposition of amyloid in numerous tissues. Early mortality from cardiac damage remains high. As depth of organ response carries a prognostic significance, combining anti-plasma cell and anti-amyloid therapies might hold the key to achieving long lasting responses. We report a series of patients who received 2 monoclonal antibodies, anti-CD38 and anti-amyloid, simultaneously.Materials and MethodsWe describe the characteristics and outcomes of 19 patients who received daratumumab (anti-CD38) on progression with front-line therapy for AL, 9 of whom were on concurrent dual monoclonal antibody treatment with daratumumab and NEOD001 (anti-amyloid), and also provide data on the schedule, safety, and tolerability of intravenous infusions of these monoclonal antibodies.ResultsThe 9 patients who received treatment with dual monoclonal antibodies achieved a high rate (100%) of hematologic response in a median of 33 days. There was no significant toxicity to dual monoclonal antibody therapy. Seven of the 8 met criteria for cardiac response, achieved in less than 3 months of combined therapy. Ten patients who received daratumumab alone also had high rates of hematologic and organ responses.ConclusionsMonoclonal antibodies with distinctly different targets can be safely combined in patients with AL and cardiac involvement. Patients experienced high rates of hematologic and cardiac response with combined anti-CD38 and anti-amyloid monoclonal antibody therapies. Further study of this combined approach is warranted.     

Diagnostic value of bright spotty lesions on MRI after a first episode of acute myelopathy

Background and purposeTo determine the diagnostic value of bright spotty lesions (BSLs) for aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (NMOSD^AQP4+), the predictive value of axial-BSLs for AQP4-IgG seropositivity, and the radio-clinical differences in NMOSD^AQP4+ patients with and without axial-BSLs.Materials and methodsRetrospective study that included patients aged ≥ 16 years, with a first acute spinal cord syndrome between 2005 and 2018 and abnormal spinal cord MRI with axial and sagittal T2 sequences. Patients with MRI findings consistent with compressive myelopathy were excluded. All spinal cord MRI were retrospectively evaluated for the presence of BSLs by 2 radiologists blinded to the diagnosis of acute myelopathy.ResultsA total of 82 patients were included; 15 aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder patients (NMOSD^AQP4+), and 67 other patients, considered as the other causes of myelopathy (OM) group. The specificity of axial-BSLs for NMOSD^AQP4+ patients was 94.0% (95% CI [85.6 to 97.7]). The sensitivity was 40.0% (95% CI [19.8 to 64.3]). In the multivariable analysis, the only MRI characteristic associated with AQP4-IgG positivity was the presence of axial-BSLs (OR: 9.2, 95% CI [1.2 to 72.9]; P = 0.022). In NMOSD^AQP4+ patients, the median of cord expansion ratio was higher with axial-BSL (1.2, IQR [1.1–1.3]) than without axial-BSL (1.1, IQR [1.0–1.2]; P = 0.046).ConclusionAfter a first acute spinal cord syndrome, the presence of axial-BSLs on spinal cord MRI seems very specific for NMOSD^AQP4+ and seems to be a predictor radiological marker of AQP4-IgG positivity.     

帕博丽珠单抗治疗晚期黑色素瘤的不良事件及相关性分析

背景与目的:免疫检查点抑制剂(immune checkpoint inhibitor,ICI)已成为肿瘤治疗的重要手段,然而伴随其显著疗效的是药物相关不良反应。观察帕博丽珠单抗在晚期黑色素瘤治疗中的安全性;初步探讨程序性死亡[蛋白]-1(programmed death-1,PD-1)单抗不良事件发生的预测因子及与疗效的相关性。方法:收集2016年8月-2017年7月期间在北京大学肿瘤医院入组一项"帕博丽珠单抗作为二线治疗中国局部晚期或转移性黑色素瘤的Ⅰb期临床研究(Keynote-151)"的54例患者的临床资料,包括性别、年龄、疾病分期、原发部位、既往化疗史、美国东部肿瘤协作组(Eastern Cooperative Oncology Group,ECOG)评分及基线外周血细胞计数,以及药物治疗相关不良事件和疗效相关信息。不良事件根据通用不良事件术语标准(Common Terminology Criteria Adverse Events,CTCAE)4.03版评价,疗效根据实体肿瘤疗效评价标准(Response Evaluation Criteria in Solid Tumors,RECIST)1.1标准评估。结果:帕博丽珠单抗在晚期黑色素瘤治疗中不良事件发生率达88.9%(48/54),严重不良事件发生率为13.0%(7/54),无死亡病例;肝毒性是导致中断和终止用药的主要原因;分析严重不良事件的发生与所观察各项临床特征及实验室检查指标之间均无显著相关性;不良事件的发生与疗效相关分析提示白癜风(P=0.001)和甲状腺功能异常(P=0.007)与疗效相关。结论:帕博丽珠单抗治疗晚期黑色素瘤不良反应发生率较高,但以1~2级为主,耐受性较好;肝毒性对试验药物应用影响最大;白癜风和甲状腺功能异常均可能是疗效较好的预测因子。     

Monoclonal Gammopathies After Renal Transplantation: A Single-center Study

IntroductionPlasma cell disorders (PCDs) are clonal plasma cell disorders that include conditions such as monoclonal gammopathy of undetermined significance (MGUS), monoclonal gammopathy of renal significance (MGRS), multiple myeloma (MM), smoldering MM (SMM), solitary plasmacytoma, and light-chain (AL) amyloidosis. The risk factors associated with and the clinical course of PCDs after renal transplantation is not well established although immunosuppressive protocols may impact the incidence and natural history of PCDs posttransplant.Patients and MethodsThis single-center retrospective study evaluated patients with a history of renal transplant who developed a PCD between January 1, 2014-December 31, 2018.ResultA total of 41 patients met the inclusion criteria including 29 with MGUS and 12 with symptomatic PCD (4 with MM, 2 with SMM, 4 with MGRS, 1 with AL amyloidosis, and 1 with solitary plasmacytoma). The median follow-up of survivors was 41.6 months. Three patients (1 with MGUS and 2 with MGRS) progressed to MM during the follow-up period. There was a male preponderance in both groups. There was no correlation between the donor and immunosuppressive regimen and the development of a PCD. Patients with symptomatic PCD had higher serum creatinine and M-protein levels at diagnosis and higher free light chain ratio and plasma cell burden. There was also a higher percentage of allograft failure noted in the symptomatic PCD subset 50% (n = 6), whereas only 23% (n = 7) of patients had allograft failure in the MGUS group.ConclusionThis study shows the importance of considering monoclonal gammopathy in the differential of renal dysfunction after kidney transplant and the need to follow these patients closely to monitor for progression to symptomatic PCD.