Citations

Myelin oligodendrocyte glycoprotein (MOG) antibody–associated disease (MOGAD) is an inflammatory demyelinating CNS condition characterized by the presence of MOG autoantibodies. We sought to investigate whether human MOG autoantibodies are capable of mediating damage to MOG-expressing cells through multiple mechanisms. We developed high-throughput assays to measure complement activity (CA), complement-dependent cytotoxicity (CDC), antibody-dependent cellular phagocytosis (ADCP), and antibody-dependent cellular cytotoxicity (ADCC) of live MOG-expressing cells. MOGAD patient sera effectively mediate all of these effector functions. Our collective analyses reveal that (a) cytotoxicity is not incumbent on MOG autoantibody quantity alone; (b) engagement of effector functions by MOGAD patient serum is bimodal, with some sera exhibiting cytotoxic capacity while others did not; (c) the magnitude of CDC and ADCP is elevated closer to relapse, while MOG-IgG binding is not; and (d) all IgG subclasses can damage MOG-expressing cells. Histopathology from a representative MOGAD case revealed congruence between lesion histology and serum CDC and ADCP, and we identified NK cells, mediators of ADCC, in the cerebrospinal fluid of relapsing patients with MOGAD. Thus, MOGAD-derived autoantibodies are cytotoxic to MOG-expressing cells through multiple mechanisms, and assays quantifying CDC and ADCP may prove to be effective tools for predicting risk of future relapses.

Background Cardiac troponin (cTn) can be elevated in many patients presenting to the emergency department (ED) with chest pain but without a diagnosis of acute coronary syndrome (ACS). We compared the prognostic significance of cTn in these different populations. Methods We retrospectively analyzed the CHOPIN study, which enrolled patients who presented to the ED with chest pain. Patients were grouped as ACS, non-ACS cardiovascular disease, noncardiac chest pain and chest pain not otherwise specified (NOS). We examined the prognostic ability of cTnI for the clinical endpoints of mortality and major adverse cardiovascular event (MACE; a composite of acute myocardial infarction, unstable angina, revascularization, reinfarction, and congestive heart failure and stroke) at 180-day follow-up. Results Among 1982 patients analyzed, 14% had ACS, 21% had non-ACS cardiovascular disease, 31% had a noncardiac diagnosis and 34% had chest pain NOS. cTnI elevation above the 99th percentile was observed in 52, 18, 6 and 7% in these groups, respectively. cTnI elevation was associated with mortality and MACE, and their relationships were more prominent in noncardiac diagnosis and chest pain NOS than in ACS and non-ACS cardiovascular diagnoses for mortality, and in non-ACS patients than in ACS patients for MACE (hazard ratio for doubling of cTnI 1.85, 2.05, 8.26 and 4.14, respectively; P for interaction 0.011 for mortality; 1.04, 1.23, 1.54 and 1.42, respectively; P for interaction <0.001 for MACE). Conclusion In patients presenting to the ED with chest pain, cTnI elevation was associated with a worse prognosis in non-ACS patients than in ACS patients.

Introduction: Copeptin has demonstrated a role in early rule out for acute myocardial infarction in combination with a negative troponin. However, the value of copeptin in patients with a positive troponin is not established. Hypothesis: The addition of a baseline copeptin at chest pain presentation will improve risk stratification in patients with mild troponin elevation. Methods: The multi-center CHOPIN trial enrolled 2071 acute chest pain patients. All subjects with ST segment elevations were excluded from this analysis. Of the remaining patients, 124 had a mildly elevated troponin (defined by < 2x URL) and were included in the study cohort. Baseline cTnI and copeptin levels were drawn on presentation, and another cTnI at 2 hours. Copeptin ≤14 pmol/l and troponin deltas ≤10% from baseline were considered positive. Two independent blinded cardiologists adjudicated AMI diagnosis. The value of a baseline copeptin in this cohort was assessed using AMI incidence, odds ratio, sensitivity, and negative predictive value (NPV). Results: Of the 124 patients in the study cohort, 73 (59%) had an elevated copeptin and an associated AMI incidence of 25% (18 AMIs). The remaining 51 patients (41%) were copeptin negative and diagnosed with 3 AMIs, an incidence of 5.9% (p = 0.006, figure 1). A positive copeptin increased the likelihood of AMI diagnosis with an odds ratio of 5.3 (95% CI: 1.5-19.2). The sensitivity and NPV for AMI were 86% and 94%, both of which were higher than the delta troponin (table 1). When an initial copeptin was combined with the delta troponin the sensitivity and NPV for AMI improved to 100%. Conclusion: Use of copeptin in chest pain patients with mild troponin elevation provides further risk stratification. The combination of copeptin with a delta troponin may aid in earlier AMI rule out in this subset of patients. This approach could be especially relevant as the increasing use of high sensitivity troponin assays leads to greater rates of mild troponin elevations.

Background: The observed incidence of type 2 myocardial infarction (T2MI) is expected to increase with the implementation of increasingly sensitive cTn assays. However, it remains to be determined how to diagnose, risk-stratify, and treat patients with T2MI. We aimed to discriminate and risk-stratify T2MI using biomarkers. Methods: Patients presenting to the emergency department with chest pain, enrolled in the CHOPIN study (Copeptin Helps in the early detection Of Patients with acute myocardial INfarction), were retrospectively analyzed. Two cardiologists adjudicated type 1 MI (T1MI) and T2MI. The prognostic ability of several biomarkers alone or in combination to discriminate T2MI from T1MI was investigated using receiver operating characteristic curve analysis. The biomarkers analyzed were cTnI, copeptin, MR-proANP (midregional proatrial natriuretic peptide), CT-proET1 (C-terminal proendothelin-1), MR-proADM (midregional proadrenomedullin), and procalcitonin. The prognostic utility of these biomarkers for all-cause mortality and major adverse cardiovascular event (a composite of acute myocardial infarction, unstable angina pectoris, reinfarction, heart failure, and stroke) at 180-day follow-up was also investigated. Results: Among the 2071 patients, T1MI and T2MI were adjudicated in 94 and 176 patients, respectively. Patients with T1MI had higher levels of baseline cTnI, whereas those with T2MI had higher baseline levels of MR-proANP, CT-proET1, MR-proADM, and procalcitonin. The area under the receiver operating characteristic curve for the diagnosis of T2MI was higher for CT-proET1, MR-proADM, and MR-proANP (0.765, 0.750, and 0.733, respectively) than for cTnI (0.631). Combining all biomarkers resulted in a similar accuracy to a model using clinical variables and cTnI (0.854 versus 0.884, P =0.294). Addition of biomarkers to the clinical model yielded the highest area under the receiver operating characteristic curve (0.917). Other biomarkers, but not cTnI, were associated with mortality and major adverse cardiovascular event at 180 days among all patients, with no interaction between the diagnosis of T1MI or T2MI. Conclusions: Assessment of biomarkers reflecting pathophysiologic processes occurring with T2MI might help differentiate it from T1MI. All biomarkers measured, except cTnI, were significant predictors of prognosis, regardless of the type of myocardial infarction.

ABSTRACT Introduction : A randomized trial demonstrated benefit from thymectomy in nonthymomatous acetylcholine receptor (AChR)‐antibody positive myasthenia gravis (MG). Uncontrolled observational and histologic studies suggest thymectomy may not be efficacious in anti–muscle‐specific kinase (MuSK)‐MG. Methods : The therapeutic impact of thymectomy was evaluated from data collected for a multicenter, retrospective blinded review of rituximab in MuSK‐MG. Results : Baseline characteristics were similar between thymectomy ( n = 26) and nonthymectomy ( n = 29) groups, including treatment with rituximab (42% vs. 45%). At last visit, 35% of thymectomy subjects reached the primary endpoint, a Myasthenia Gravis Foundation of America (MGFA) post‐intervention status (PIS) score of minimal manifestations (MM) or better, compared with 55% of controls ( P = 0.17). After controlling for age at onset of MG, rituximab, prednisone, and intravenous immunoglobulin/plasma exchange treatment, thymectomy was not associated with greater likelihood of favorable clinical outcome (odds ratio = 0.43, 95% confidence interval 0.12–1.53, P = 0.19). Discussion : Thymectomy was not associated with additional clinical improvement in this multicenter cohort of MuSK‐MG patients. Muscle Nerve 59:404–410, 2019

Background: Copeptin in combination with troponin has been shown to have incremental value for the early rule-out of myocardial infarction, but its performance in Black patients specifically has never been examined. In light of a potential for wider use, data on copeptin in different relevant cohorts are needed. This is the first study to determine whether copeptin is equally effective at ruling out myocardial infarction in Black and Caucasian races. Methods: This analysis of the CHOPIN trial included 792 Black and 1075 Caucasian patients who presented to the emergency department with chest pain and had troponin-I and copeptin levels drawn. Results: One hundred and forty-nine patients were diagnosed with myocardial infarction (54 Black and 95 Caucasian). The negative predictive value of copeptin at a cut-off of 14 pmol/l (as in the CHOPIN study) for myocardial infarction was higher in Blacks (98.0%, 95% confidence interval (CI) 96.2–99.1%) than Caucasians (94.1%, 95% CI 92.1–95.7%). The sensitivity at 14 pmol/l was higher in Blacks (83.3%, 95% CI 70.7–92.1%) than Caucasians (53.7%, 95% CI 43.2–64.0%). After controlling for age, hypertension, heart failure, chronic kidney disease and body mass index in a logistic regression model, the interaction term had a P value of 0.03. A cut-off of 6 pmol/l showed similar sensitivity in Caucasians as 14 pmol/l in Blacks. Conclusions: This is the first study to identify a difference in the performance of copeptin to rule out myocardial infarction between Blacks and Caucasians, with increased negative predictive value and sensitivity in the Black population at a cut-off of 14 pmol/l. This also holds true for non-ST-segment elevation myocardial infarction and, although numbers were small, similar trends exist in the normal troponin population. This may have significant implications for early rule-out strategies using copeptin.

AbstractObjectivesChest pain is a common complaint to emergency departments (EDs) and clinical risk factors are used to predict which patients are at risk for worse outcomes and mortality. The goal was to assess the novel biomarker midregional proadrenomedullin (MR‐proADM) in prediction of mortality and major adverse cardiac events (MACE).MethodsThis was a subanalysis of the CHOPIN study, a 16‐center prospective trial that enrolled 2,071 patients presenting with chest pain within 6 hours of onset. The primary endpoint was 6‐month all‐cause mortality and the secondary endpoint was 30‐day and 6‐month MACE: ED visits or hospitalization for acute myocardial infarction, unstable angina, reinfarction, revascularization, and heart failure.ResultsMR‐proADM performed similarly to troponin (cTnI; c‐statistic = 0.845 and 0.794, respectively) for mortality prediction in all subjects and had similar results in those with noncardiac diagnoses. MR‐proADM concentrations were stratified by decile, and the cohort in the top decile had a 9.8% 6‐month mortality risk versus 0.9% risk for those in the bottom nine deciles (p < 0.0001). MR‐proADM, history of coronary artery disease (CAD), and hypertension were predictors of short‐term MACE, while history of CAD, hypertension, cTnI, and MR‐proADM were predictors of long‐term MACE.ConclusionsIn patients with chest pain, MR‐proADM predicts mortality and MACE in all‐comers with chest pain and has similar prediction in those with a noncardiac diagnosis. This exploratory analysis is primarily hypotheses‐generating and future prospective studies to identify its utility in risk stratification should be considered.