scholarly journals Myasthenia gravis AChR antibodies inhibit function of rapsyn-clustered AChRs

2020 ◽  
Vol 91 (5) ◽  
pp. 526-532 ◽  
Author(s):  
Hakan Cetin ◽  
Richard Webster ◽  
Wei Wei Liu ◽  
Akiko Nagaishi ◽  
Inga Koneczny ◽  
...  
Keyword(s):  
Myasthenia Gravis ◽  
Scaffolding Protein ◽  
Patch Clamping ◽  
Direct Inhibition ◽  
Serum Samples ◽  
Disease Mechanisms ◽  
Healthy Control ◽  
Induced Currents ◽  
Sensitivity Specificity ◽  
Fast Perfusion

ObjectiveDirect inhibition of acetylcholine receptor (AChR) function by autoantibodies (Abs) is considered a rare pathogenic mechanism in myasthenia gravis (MG), but is usually studied on AChRs expressed in cell lines, rather than tightly clustered by the intracellular scaffolding protein, rapsyn, as at the intact neuromuscular junction. We hypothesised that clustered AChRs would provide a better target for investigating the functional effects of AChR-Abs.MethodsAcetylcholine-induced currents were measured using whole-cell patch clamping and a fast perfusion system to assess fast (<2 min) functional effects of the serum samples. The sensitivity, specificity and rapidity of the system were first demonstrated by applying maternal AChR-Ab positive plasmas known to inhibit fetal AChR function in TE671 cells. Eleven previously untested AChR-Ab positive MG sera, 10 AChR-Ab negative MG sera and 5 healthy control sera were then applied to unclustered and rapsyn-clustered human adult AChRs in CN21 cells.ResultsThe maternal AChR-Ab positive plasmas reduced fetal AChR currents, but not adult AChR currents, by >80% within 100 s. Only 2/11 AChR-Ab positive sera inhibited AChR currents in unclustered AChRs, but 6/11 AChR-Ab positive sera compared with none of the 10 AChR-Ab negative sera (p=0.0020) inhibited rapsyn-clustered AChR currents, and current inhibition by the AChR-Ab positive sera was greater when the AChRs were clustered (p=0.0385). None of the sera had detectable effects on desensitisation or recovery from desensitisation.ConclusionThese results show that antibodies can inhibit AChR function rapidly and demonstrate the importance of clustering in exploring pathogenic disease mechanisms of MG Abs.

scholarly journals COT-04 Circulating biomarker for glioblastoma and primary central nervous system lymphoma -Next Generation Sequencing of small noncoding RNA-

2020 ◽  
Vol 2 (Supplement_3) ◽  
pp. ii21-ii21
Author(s):  
Shumpei Onishi ◽  
Fumiyuki Yamasaki ◽  
Motoki Takano ◽  
Ushio Yonezawa ◽  
Kazuhiko Sugiyama ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Noncoding Rna ◽  
Central Nervous System Lymphoma ◽  
Serum Samples ◽  
Small Noncoding Rna ◽  
Non Invasive ◽  
Diagnostic Models ◽  
Healthy Control ◽  
Generation Sequencing

Abstract Objective: Glioblastoma (GBM) and Primary Central Nervous System Lymphoma (PCNSL) are common intracranial malignant tumors. They sometimes present similar radiological findings and diagnoses could be difficult without surgical biopsy. For improving the current management, development of non-invasive biomarkers are desired. In this study, we explored the differently expressed circulating small noncoding RNA (sncRNA) in serum for specific diagnostic tool of GBM and PCNSL. Material & Methods: Serum samples were obtained from three groups: 1) GBM patients (N=26), 2) PCNSL patients (N=14) 3) healthy control (N=114). The total small RNAs were extracted from serum. The whole expression profiles of serum sncRNAs were measured using Next-Generation Sequencing System. We analyzed serum levels of sncRNAs (15–55 nt) in each serum samples. The difference of sncRNAs expression profile among three groups were compared. Data analysis was performed by logistic regression analysis followed by leave-one-out cross-validation (LOOCV). The accuracy of diagnostic models of sncRNAs combination were evaluated by receiver operating characteristic (ROC) analysis. Results: We created the combination models using three sncRNA in each models based on the logistic regression analysis. The model 1 (based on sncRNA-X1, X2 and X3) enabled to differentiate GBM patients form healthy control with a sensitivity of 92.3% and a specificity of 99.2% (AUC: 0.993). The model 2 (based on sncRNA-Y1, Y2 and Y3) enabled to differentiate PCNSL patients form healthy control with a sensitivity of 100% and a specificity of 93.9% (AUC: 0.984). The model 3 (based on sncRNA-Z1, Z2 and Z3) enabled to differentiate GBM patients form PCNSL patients with a sensitivity of 92.3% and a specificity of 78.6% (AUC: 0.920). Conclusion: We found three diagnostic models of serum sncRNAs as non-invasive biomarkers potentially useful for detection of GBM and PCNSL from healthy control, and for differentiation GBM from PCNSL.

scholarly journals Investigation of the rapid immunochromatographic test performance in the diagnosis of syphilis; comparison of four serological methods

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Huseyin Agah Terzi ◽  
Ozlem Aydemir ◽  
Engin Karakece ◽  
Huseyin Hatipoglu ◽  
Mehmet Olmez ◽  
...  
Keyword(s):  
Test Performance ◽  
Gold Standard ◽  
Treponema Pallidum ◽  
Rapid Test ◽  
Immunochromatographic Test ◽  
Rapid Plasma Reagin ◽  
Serum Samples ◽  
Hemagglutination Assay ◽  
Predictive Values ◽  
Sensitivity Specificity

AbstractObjectivesTo test the performance of the newly available rapid test for syphilis, we compared it with Treponema pallidum hemagglutination assay (TPHA). Additionally, we investigated the performance of rapid plasma reagin (RPR) and chemiluminescence microparticle immunoassays (CMIA) at our laboratory using TPHA as a gold standard.MethodsThe serum samples of 595 patients with the pre-diagnosis of syphilis were studied by four serological methods. The sensitivity, specificity, and predictive values of RPR, CMIA, and syphilis rapid test were assessed by utilizing TPHA as a gold standard for the diagnosis of syphilis.ResultsOf the patients, 6.2% (37/595) had positive RPR, 5.5% (33/595) had positive CMIA, 5.5% (33/595) had a positive rapid immunochromatographic method and 5% (30/595) had positive TPHA. When TPHA results were taken as the reference, the sensitivity of the rapid test for syphilis was 100%, the specificity was 99.5%, PPV was 90.9%, and NPV was 100.0%.ConclusionsIt was observed that the rapid test for syphilis used in the study was quite successful, its cost was appropriate, and the test was very fast and easy to apply. At the same time, the agreement between syphilis rapid test and TPHA was found to be excellent.

scholarly journals Fc-Receptor Targeted Therapies for the Treatment of Myasthenia gravis

2021 ◽  
Vol 22 (11) ◽  
pp. 5755
Author(s):  
Christian W. Keller ◽  
Marc Pawlitzki ◽  
Heinz Wiendl ◽  
Jan D. Lünemann
Keyword(s):  
Myasthenia Gravis ◽  
Acetylcholine Receptors ◽  
Postsynaptic Membrane ◽  
Fc Receptor ◽  
Igg Antibodies ◽  
Effector Functions ◽  
Disease Remission ◽  
Disease Mechanisms ◽  
First Choice ◽  
Complement Deposition

Myasthenia gravis (MG) is an autoimmune disease in which immunoglobulin G (IgG) antibodies (Abs) bind to acetylcholine receptors (AChR) or to functionally related molecules in the postsynaptic membrane at the neuromuscular junction. IgG crystallizable fragment (Fc)-mediated effector functions, such as antibody-dependent complement deposition, contribute to disease development and progression. Despite progress in understanding Ab-mediated disease mechanisms, immunotherapy of MG remained rather unspecific with corticosteroids and maintenance with immunosuppressants as first choice drugs for most patients. More specific therapeutic IgG Fc-based platforms that reduce serum half-life or effector functions of pathogenic MG-related Abs are currently being developed, tested in clinical trials or have recently been successfully translated into the clinic. In this review, we illustrate mechanisms of action and clinical efficacies of emerging Fc-mediated therapeutics such as neonatal Fc receptor (FcRn)-targeting agents. Furthermore, we evaluate prospects of therapies targeting classical Fc receptors that have shown promising therapeutic efficacy in other antibody-mediated conditions. Increased availability of Fc- and Fc receptor-targeting biologics might foster the development of personalized immunotherapies with the potential to induce sustained disease remission in patients with MG.

A Simple, Rapid and Non-Radiolabeled Immune Assay to Detect Anti-AChR Antibodies in Myasthenia Gravis

2018 ◽  
Vol 50 (3) ◽  
pp. 229-235 ◽  
Author(s):  
Suresh Bokoliya ◽  
Shripad Patil ◽  
Madhu Nagappa ◽  
Arun Taly
Keyword(s):  
Myasthenia Gravis ◽  
Case Control Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
Test Results ◽  
Dot Blot ◽  
Dot Blot Assay ◽  
Healthy Control ◽  
Neurological Illnesses ◽  
Control Study ◽  
Immune Assay

AbstractObjectiveTo assess the practicality of dot-blot testing for rapid and sensitive detection of the antiacetylcholine receptor (anti-AChR) antibodies in myasthenia gravis (MG).MethodsIn this case-control study, we tested serum specimens of 85 patients with MG, 85 healthy control individuals, and 85 patients without MG who have other autoimmune and neurological illnesses. All the serum specimens were tested for anti-AChR antibodies using 3 assays: in-house enzyme-linked immunosorbent assay (ELISA), the dot-blot assay, and commercial ELISA.ResultsIn-house ELISA, commercial ELISA, and dot-blot test results were positive for anti-AChR antibodies in 65 (76.5%) patients with MG. The results of all 3 tests were negative for anti-AChR antibodies in healthy controls and patients without MG. We observed perfect concordance (K = 1, P <.001) between all 3 tests. In-house ELISA correlated significantly (r = 0.873, P <.001) with commercial ELISA. In-house ELISA and the dot-blot test demonstrated similar diagnostic performance in detecting anti-AChR antibodies.ConclusionsThe dot-blot assay is a simple, nonradioactive immune assay for rapid detection of anti-AChR antibodies in MG.

scholarly journals Studying the Role of C-Reactive Protein in Patients with Sleeve Gastrectomy in Baghdad

2021 ◽  
Vol 3 (1) ◽  
pp. 55-60
Author(s):  
Mohammed Abbas Fadil ◽  
Raya Ezat Maroof ◽  
Moayed Abbas Fadil
Keyword(s):  
Sleeve Gastrectomy ◽  
Healthy Person ◽  
Control Group ◽  
C Reactive Protein ◽  
Serum Samples ◽  
Reactive Protein ◽  
Medical City ◽  
Healthy Control ◽  
And Control

Obesity and severe obesity are increasing serious health problems with an epidemic percentage in most countries. In Sleeve gastrectomy, a part of the stomach structure is removed, limiting its capacity by about two to three. A total of thirty blood samples were collected from patients with obesity and the result was compared with healthy person throughout the time from November 2019 to September 2020. Before sleeve gastrectomy and after more than 6 months of sleeve surgery, the sample was collected from the Medical City/Baghdad Teaching Hospital, the withdrawal was again taken at home to have pre and post sleeve gastrectomy, Patient age ranged between [20-46] years for obese patients and healthy control. Then the serum samples were obtained from patients and control group to screen for C-reactive protein by agglutination method. The result of the present study found that the positivity of CRP in pre-operation is higher than that of post-operative with high significance [P<0.005].

scholarly journals Development of in-house serological methods for diagnosis and surveillance of chikungunya

2017 ◽  
Vol 41 ◽  
pp. 1 ◽  
Author(s):  
Ángel Balmaseda ◽  
Saira Saborío Galo ◽  
Karla González ◽  
Yolanda Téllez ◽  
Nadezna García ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Epidemiological Surveillance ◽  
Diagnostic Systems ◽  
Serum Samples ◽  
Hyperimmune Serum ◽  
Predictive Values ◽  
Processing Times ◽  
Igm Elisa ◽  
Sensitivity Specificity ◽  
Research Demands

Objective.To develop and evaluate serological methods for chikungunya diagnosis and research in Nicaragua.Methods.Two IgM ELISA capture systems (MAC-ELISA) for diagnosis of acute chikungunya virus (CHIKV) infections, and two Inhibition ELISA Methods (IEM) to measure total antibodies against CHIKV were developed using monoclonal antibodies (mAbs) and hyperimmune serum at the National Virology Laboratory of Nicaragua in 2014–2015. The sensitivity, specificity, predictive values, and agreement of the MAC-ELISAs were obtained by comparing the results of 198 samples (116 positive; 82 negative) with the Centers for Disease Control and Prevention’s IgM ELISA (Atlanta, Georgia, United States; CDC-MAC-ELISA). For clinical evaluation of the four serological techniques, 260 paired acute and convalescent phase serum samples of suspected chikungunya cases were used.Results.All four assays were standardized by determining the optimal concentrations of the different reagents. Processing times were substantially reduced compared to the CDC-MAC-ELISA. For the MAC-ELISA systems, a sensitivity of 96.6% and 97.4%, and a specificity of 98.8% and 91.5% were obtained using mAb and hyperimmune serum, respectively, compared with the CDC method. Clinical evaluation of the four serological techniques versus the CDC real-time RT-PCR assay resulted in a sensitivity of 95.7% and a specificity of 88.8%–95.9%.Conclusion.Two MAC-ELISA and two IEM systems were standardized, demonstrating very good quality for chikungunya diagnosis and research demands. This will achieve more efficient epidemiological surveillance in Nicaragua, the first country in Central America to produce its own reagents for serological diagnosis of CHIKV. The methods evaluated here can be applied in other countries and will contribute to sustainable diagnostic systems to combat the disease.

A Negative Antinuclear Antibody Does Not Indicate Autoantibody Negativity in Myositis: Role of Anticytoplasmic Antibody as a Screening Test for Antisynthetase Syndrome

2016 ◽  
Vol 44 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Rohit Aggarwal ◽  
Namrata Dhillon ◽  
Noreen Fertig ◽  
Diane Koontz ◽  
Zengbiao Qi ◽  
...  
Keyword(s):  
Lupus Erythematosus ◽  
Predictive Value ◽  
Antinuclear Antibody ◽  
High Sensitivity ◽  
Epithelial Cell Line ◽  
Antisynthetase Syndrome ◽  
Control Groups ◽  
Serum Samples ◽  
Cytoplasmic Staining ◽  
Sensitivity Specificity

Objective.To evaluate the utility of anticytoplasmic autoantibody (anti-CytAb) in antisynthetase antibody–positive (anti-SynAb+) patients.Methods.Anti-SynAb+ patients were evaluated for antinuclear antibody (ANA) and anti-CytAb [cytoplasmic staining on indirect immunofluorescence (IIF)] positivity. Anti-SynAb+ patients included those possessing anti-Jo1 and other antisynthetase autoantibodies. Control groups included scleroderma, systemic lupus erythematosus, Sjögren syndrome, rheumatoid arthritis, and healthy subjects. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy of anti-CytAb, and ANA were assessed. Anti-CytAb and ANA testing was done by IIF on human epithelial cell line 2, both reported on each serum sample without knowledge of the clinical diagnosis or final anti-SynAb results.Results.Anti-SynAb+ patients (n = 202; Jo1, n = 122; non-Jo1, n = 80) between 1985–2013 with available serum samples were assessed. Anti-CytAb showed high sensitivity (72%), specificity (89%), NPV (95%), and accuracy (86%), but only modest PPV (54%) for anti-SynAb positivity. In contrast, ANA showed only modest sensitivity (50%) and poor specificity (6%), PPV (9%), NPV (41%), and accuracy (12%). Positive anti-CytAb was significantly greater in the anti-SynAb+ patients than ANA positivity (72% vs 50%, p < 0.001), and 81/99 (82%) ANA-negative patients in the anti-SynAb+ cohort had positive anti-CytAb. In contrast, the control groups showed high rates for ANA positivity (93.5%), but very low rates for anti-CytAb positivity (11.5%). Combining anti-CytAb or Jo1 positivity showed high sensitivity (92%) and specificity (89%) for identification of anti-SynAb+ patients.Conclusion.Assessing patients for anti-CytAb serves as an excellent screen for anti-SynAb+ patients using simple IIF. Cytoplasmic staining should be assessed and reported for patients suspected of having antisynthetase syndrome and a negative ANA should not be used to exclude this diagnosis.

scholarly journals An MRM-Based Multiplexed Quantification Assay for Human Adipokines and Apolipoproteins

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 775 ◽  
Author(s):  
Laura Krieg ◽  
Alexandra Schaffert ◽  
Matthias Kern ◽  
Kathrin Landgraf ◽  
Martin Wabitsch ◽  
...  
Keyword(s):  
Serum Proteins ◽  
Multiple Reaction Monitoring ◽  
Normal Weight ◽  
The Body ◽  
Serum Samples ◽  
Human Adipocyte ◽  
Disease Mechanisms ◽  
Adipocyte Cell ◽  
Functional Analyses ◽  
Culture Supernatants

Adipokines and apolipoproteins are key regulators and potential biomarkers in obesity and associated diseases and their quantitative assessment is crucial for functional analyses to understand disease mechanisms. Compared to routinely used ELISAs, multiple reaction monitoring (MRM)-based mass spectrometry allows multiplexing and detection of proteins for which antibodies are not available. Thus, we established an MRM method to quantify 9 adipokines and 10 apolipoproteins in human serum. We optimized sample preparation by depleting the two most abundant serum proteins for improved detectability of low abundant proteins. Intra-day and inter-day imprecision were below 16.5%, demonstrating a high accuracy. In 50 serum samples from participants with either normal weight or obesity, we quantified 8 adipokines and 10 apolipoproteins. Significantly different abundances were observed for five adipokines (adipsin, adiponectin, chemerin, leptin, vaspin) and four apolipoproteins (apo-B100/-C2/-C4/-D) between the body mass index (BMI) groups. Additionally, we applied our MRM assay to serum samples from normal weight children and human adipocyte cell culture supernatants to proof the feasibility for large cohort studies and distinct biological matrices. In summary, this multiplexed assay facilitated the investigation of relationships between adipokines or apolipoproteins and phenotypes or clinical parameters in large cohorts, which may contribute to disease prediction approaches in the future.

Serum Calprotectin as a Blood-Based Biomarker for Monitoring Knee Osteoarthritis at Early but Not Late Stages

Cartilage ◽  
2020 ◽  
pp. 194760352096116
Author(s):  
Amin Safa ◽  
Abolfazl Bagherifard ◽  
Hamadalla Hadi Al-Baseesee ◽  
Azade Amini Kadijani ◽  
Hooman Yahyazadeh ◽  
...  
Keyword(s):  
Disease Duration ◽  
Early Stage ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Knee Oa ◽  
Calprotectin Level ◽  
Healthy Control ◽  
Grade Ii ◽  
Late Stages

Objective The identification of early-stage osteoarthritis (OA) is crucial for the deceleration of its progression; however, no reliable biomarker is available for this purpose. The current study aimed to determine the role of serum calprotectin in the detection of early-stage knee OA. Design In a case-control study, serum samples were collected from 84 patients with primary bilateral knee OA and 52 healthy controls. The radiographic grading of knee OA was performed using the Kellgren-Lawrence classification system. Serum concentrations of calprotectin were measured using an enzyme-linked immunosorbent assay. Results The mean serum calprotectin level was 2908 ± 2516 ng/mL in OA patients and 901 ± 875 ng/mL in healthy control subjects ( P < 0.001). Mean serum calprotectin levels were significantly higher in the lower stages of OA: 3740 ± 2728 ng/mL in OA grade I, 3100 ± 2084 ng/mL in OA grade II, 2246 ± 1418 ng/mL in OA grade III, and 2035 ± 765 ng/mL in OA grade IV ( P = 0.047). Serum calprotectin levels were significantly higher in patients with a disease duration <42 months compared with those with a disease duration >42 months ( P = 0.043). Conclusion Serum calprotectin level increases significantly in the early stages of OA and shows a reverse association with disease severity. Therefore, it could be suggested as a promising blood-based marker for early-stage knee OA.

scholarly journals Discovery and Validation of a Six-Marker Serum Protein Signature for the Diagnosis of Active Pulmonary Tuberculosis

2017 ◽  
Vol 55 (10) ◽  
pp. 3057-3071 ◽  
Author(s):  
Mary A. De Groote ◽  
David G. Sterling ◽  
Thomas Hraha ◽  
Theresa M. Russell ◽  
Louis S. Green ◽  
...  
Keyword(s):  
Serum Protein ◽  
Protein A ◽  
Performance Criteria ◽  
Sputum Smear ◽  
Protein Biomarkers ◽  
Serum Samples ◽  
Active Pulmonary Tuberculosis ◽  
Hiv Coinfection ◽  
Tb Diagnostics ◽  
Sensitivity Specificity

ABSTRACT New non-sputum biomarker tests for active tuberculosis (TB) diagnostics are of the highest priority for global TB control. We performed in-depth proteomic analysis using the 4,000-plex SOMAscan assay on 1,470 serum samples from seven countries where TB is endemic. All samples were from patients with symptoms and signs suggestive of active pulmonary TB that were systematically confirmed or ruled out for TB by culture and clinical follow-up. HIV coinfection was present in 34% of samples, and 25% were sputum smear negative. Serum protein biomarkers were identified by stability selection using L1-regularized logistic regression and by Kolmogorov-Smirnov (KS) statistics. A naive Bayes classifier using six host response markers (HR6 model), including SYWC, kallistatin, complement C9, gelsolin, testican-2, and aldolase C, performed well in a training set (area under the sensitivity-specificity curve [AUC] of 0.94) and in a blinded verification set (AUC of 0.92) to distinguish TB and non-TB samples. Differential expression was also highly significant ( P < 10 −20 ) for previously described TB markers, such as IP-10, LBP, FCG3B, and TSP4, and for many novel proteins not previously associated with TB. Proteins with the largest median fold changes were SAA (serum amyloid protein A), NPS-PLA2 (secreted phospholipase A2), and CA6 (carbonic anhydrase 6). Target product profiles (TPPs) for a non-sputum biomarker test to diagnose active TB for treatment initiation (TPP#1) and for a community-based triage or referral test (TPP#2) have been published by the WHO. With 90% sensitivity and 80% specificity, the HR6 model fell short of TPP#1 but reached TPP#2 performance criteria. In conclusion, we identified and validated a six-marker signature for active TB that warrants diagnostic development on a patient-near platform.

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