Citations

Autoantibody-mediated diseases targeting one autoantigen provide a unique opportunity to comprehensively understand the development of disease-causing B cells and autoantibodies. Convention suggests that such autoreactivities are generated during germinal center reactions. Here, we explore earlier immune checkpoints, focusing on patients with contactin-associated protein-like 2 (CASPR2)–autoantibody encephalitis. In both disease and health, high (~0.5%) frequencies of unmutated CASPR2-reactive naïve B cells were identified. By contrast, CASPR2-reactive memory B cells were exclusive to patients, and their B cell receptors demonstrated affinity-enhancing somatic mutations with pathogenic effects in neuronal cultures and mice. The unmutated, precursor memory B cell receptors showed a distinctive balance between strong CASPR2 reactivity and very limited binding across the remaining human proteome. Our results identify permissive central tolerance, defective peripheral tolerance, and autoantigen-specific tolerance thresholds in humans as sequential steps that license CASPR2-directed pathology. By leveraging the basic immunobiology, we rationally direct tolerance-restoring approaches, with an experimental paradigm applicable across autoimmunity.

Abstract Acute Myocarditis (AM) encompasses a broad spectrum of clinical presentations and causes. Despite the recent advances in cardiovascular imaging, pathology, virology, and genetics, specific therapies are still lacking. This collaborative review aims to analyse the current evidence to answer practical questions that physicians may face during the early management of patients presenting with an acute form of the disease, complicated or not. This review analyses current evidence to address practical questions posed by acute cardiovascular physicians during the early management of acute, or potentially, myocarditis. Based on the current literature, this review provides a step-by-step approach to treat AM patients from their admission in the cardiac intensive care unit (CICU) to discharge, by answering 10 clinical questions: Might this patient be suffering from an AM? Should I hospitalize this patient and, if so, where? Which cardiac imaging exam should I perform and what can I learn from it? Is this patient requiring an EMB? What should the non-invasive aetiological work-up be? Is her/his episode of AM of viral, toxic, or other origin? Does this patient need specific treatments or mechanical circulatory support? Is there an indication for guideline-directed medical heart failure treatment? When can the patient be discharged and resume physical activity? Notably, this review highlights the need to build a multidisciplinary response team to address the many diagnostic and therapeutic challenges of AM patients. It also points out the lack of evidence to guide the treatment of these patients.

Background/Purpose APS ACTION Registry was created to study the natural course of antiphospholipid syndrome (APS) over 10 years in persistently antiphospholipid antibody (aPL) positive patients with or without systemic autoimmune rheumatic diseases (SARDs). Our primary objective was to compare the characteristics of aPL-positive patients with or without thrombocytopenia (TP) and/or autoimmune hemolytic anemia (AIHA). Methods The registry inclusion criteria are positive aPL based on the Revised Sapporo APS Classification Criteria, tested at least twice within 1 year prior to enrollment. For the primary comparison of demographic, clinical, and serologic characteristics in this retrospective study, we divided patients into two groups: TP/AIHA ever and never. Thrombocytopenia was defined as a platelet count of <100,000 x 10 9 /L tested twice at least 12 weeks apart, and AIHA was defined as anemia with hemolysis and a positive direct antiglobulin test (DAT). For the secondary analysis, we compared patients with TP versus AIHA, and the immunosuppressive use stratified by systemic lupus erythematosus (SLE) classification. Results As of April 2022, of 1,039 patients (primary aPL/APS: 618 [59%]; SLE classification: 334 [31%]) included in the registry, 228 (22%) had baseline (historical or current) TP and/or AIHA (TP only: 176 [17%]; AIHA only: 35 [3%], and both: 17 [2%]). Thrombocytopenia and/or AIHA was significantly associated with Asian race, SLE classification, cardiac valve disease, catastrophic/microvascular APS, triple aPL (lupus anticoagulant, anticardiolipin antibody, and anti-β 2 -glycoprotein-I antibody) positivity, and SLE-related serologic and inflammatory markers. When 101/618 (16%) primary aPL/APS patients and 101/334 (34%) SLE patients with TP and/or AIHA were compared, azathioprine and mycophenolate mofetil were more commonly reported in lupus patients, however corticosteroid, intravenous immunoglobulin, and rituximab use were similar between groups. Conclusion In our large multi-center international cohort of persistently aPL-positive patients, approximately one-fifth had active or historical TP and/or AIHA at registry entry; half of these patients had additional SLE. Cardiac valve disease, catastrophic/microvascular APS, and triple aPL-positivity were aPL-related clinical and laboratory manifestations associated with TP and/or AIHA, suggesting a more severe APS clinical phenotype in aPL-patients with TP and/or AIHA.

ABSTRACTObjectiveTo explore pre–hematopoietic stem cell transplant (HSCT) demographic, disease, and psychological factors predictive of future transplant regret and to determine post‐HSCT variables associated with regret.Patients and MethodsHSCT candidates participated in a prospective cohort study (June 2008–October 2013) examining health behaviors and HSCT outcomes, including completion of standardized surveys at pre‐HSCT (baseline) and 1‐year post‐HSCT. Cases were participants that endorsed regret at 1‐year post‐HSCT follow‐up, and controls were participants without regret at 1 year, matched on age, sex, and transplant type. For cases and controls, pre‐HSCT psychosocial evaluations were abstracted from the electronic health record and coded to determine the Psychosocial Assessment of Candidates for Transplantation score, psychosocial stressors, and mental health diagnoses. The association of selected factors with regret was estimated with odds ratios and 95% confidence intervals from conditional logistic regression models.ResultsAt post‐HSCT, 49 participants of 638 endorsed transplant regret (8%) and formed the case group; 98 controls were matched from remaining participants. Cases and controls were well matched on age (56.6 vs. 57.2 years), sex (both groups 34.7% female), and transplant type (both groups 81.6% autologous). After controlling for the number of hospitalizations and active treatment status, conditional logistic regression revealed that patients who endorsed regret were 3.7 times (95% CI = 1.37–9.69, p = 0.008) more likely to not be in remission compared to controls at 1‐year post‐HSCT.ConclusionMatched case–control analyses revealed that no pre‐HSCT variables collected during the pre‐HSCT evaluation period were predictive of transplant regret, while poorer outcomes at 1‐year after transplant were associated with regret.

ABSTRACTBackgroundDrug‐induced hypersensitivity syndrome (DiHS), or drug reaction with eosinophilia and systemic symptoms (DRESS), is a delayed and severe immune response to certain medications. We investigated vancomycin‐induced DiHS/DRESS, notable for frequent and severe organ involvement, to describe its specific histopathology and the correlations between histopathologic and clinical findings.MethodsA retrospective review was conducted to identify patients between 2006 and 2022 who received vancomycin, had archived skin biopsy specimens, and were scored as having probable or definite DiHS/DRESS. Clinical features were retrospectively collected, and biopsy specimens were reviewed by a board‐certified dermatopathologist. A subset of histopathologic and clinical features was analyzed for statistical correlation.ResultsTwenty‐three patients met the inclusion criteria. Most biopsy specimens (87%) showed an eczematous reaction pattern; 17 (74%) showed a secondary reaction pattern. Spongiosis (87%) and neutrophilic infiltration (91%) were common epidermal characteristics. The dermal inflammatory infiltrate was frequently superficial (87%) and consistently included plasma cells (96%). Eosinophils were present in the dermis in 70% of cases. Parakeratosis negatively correlated with liver involvement and positively correlated with desquamative rash. Epidermal lymphocytes were negatively correlated with the RegiSCAR score.ConclusionsVancomycin‐associated DiHS/DRESS histopathology was characterized by a frequent eczematous reaction pattern, multiple coexisting reaction patterns, and epidermal neutrophilic infiltration.

ABSTRACTPatients with vascular anomalies (VAs) require expert multidisciplinary care. No prior studies have characterized the sociodemographic characteristics across multiple VA centers. We collected data on 5783 patients receiving care at 20 VA centers between July 1, 2020 through December 31, 2022. Male patients were underrepresented compared to the state‐level census data at 17/20 centers. Black and Asian patients were underrepresented at 14/20 and 12/20 centers, respectively. The median distance to the hospital was 48 miles, and median age was 12.0 years. These data suggest that race, sex, age, and distance from the hospital could impede the ability to access expert VA care.