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Audrey M Sigmund,* Kieran D Sahasrabudhe,* Bhavana Bhatnagar Division of Hematology, Department of Internal Medicine, The Ohio State University and the Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA*These authors contributed equally to this workCorrespondence: Bhavana BhatnagarOSU Wexner Medical Center, 320 W 10th Avenue Tel +1-614-688-7939Fax +1-614-293-6050Email Bhavana.Bhatnagar@osumc.eduAbstract: Although adults with B-cell acute lymphoblastic leukemia (B-ALL) achieve high complete remission (CR) rates following treatment with intensive multi-agent chemotherapy regimens, up to two-thirds of these patients eventually relapse. Unfortunately, adults with relapsed or refractory (R/R) B-ALL have a poor prognosis, with variable responses to salvage chemotherapy regimens and allogeneic stem cell transplant. As such, the need to develop effective and well-tolerated treatments for this patient population has been of paramount importance over the past decade. In this regard, treatment options for R/R B-ALL patients have expanded considerably over a relatively short period of time, with the approvals of blinatumomab, inotuzumab ozogamicin and tisagenlecleucel occurring within only the past six years. Blinatumomab, a CD19 x CD3 bispecific T-cell engager (BiTE) was the first of these immune therapies to receive approval, and for many patients, is used as first-line salvage therapy. A number of large clinical trials have demonstrated improved progression-free survival and overall survival for R/R B-ALL patients receiving blinatumomab as compared to those receiving conventional salvage chemotherapy. In addition to being approved for both Philadelphia chromosome-negative and Philadelphia chromosome-positive R/R B-ALL, blinatumomab is also the only ALL therapy that carries approval for the treatment of measurable residual disease (MRD). Although blinatumomab has changed the therapeutic landscape for adults with R/R B-ALL, a number of important clinical considerations and questions remain, including the potential role of blinatumomab in the frontline setting, mechanisms of resistance, optimal goal MRD level, the role of transplant following MRD clearance, the optimal place for blinatumomab in the context of other recently approved immune-mediated therapies, and real world outcomes for patients treated outside the context of clinical trials. These issues are the focus of ongoing studies, which will hopefully inform future clinical practice regarding the utility of blinatumomab in the treatment of B-ALL patients.Keywords: blinatumomab, BiTE antibody, B-cell acute lymphoblastic leukemia, relapsed and refractory disease, measurable residual disease, MRD

Chronic graft- versus -host-disease (cGVHD) is one of the primary causes of morbidity and mortality for patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HCT). In recent years, advancements in allo-HCT have allowed a broader range of patients to receive transplant, particularly older patients. We sought to assess the impact of cGVHD on outcomes in patients undergoing allo-HCT, for older patients as compared to their counterparts. We performed a retrospective analysis of all patients who underwent allo-HCT 1999-2018. Our results showed that those patients who developed cGVHD by D  + 180 had an increased risk and incidence of NRM as compared to those patients without cGVHD. There was no significant difference in outcomes for those patients with cGVHD by age (≥60 years old [yo] and <60 yo). These findings suggest the significant morbidity of cGVHD, regardless of age.

Pemphigus is a severe blistering disease caused by autoantibodies primarily against the desmosomal cadherins desmoglein (DSG)1 and DSG3, which impair desmosome integrity. Especially for the acute phase, additional treatment options allowing to reduce corticosteroids would fulfill an unmet medical need. In this study, we provide evidence that EGFR inhibition by erlotinib ameliorates pemphigus vulgaris IgG-induced acantholysis in intact human epidermis. Pemphigus vulgaris IgG caused phosphorylation of EGFR (Y845) and Rous sarcoma-related kinase in human epidermis. In line with this, a phosphotyrosine kinome analysis revealed a robust response associated with EGFR and Rous sarcoma-related kinase family kinase signaling in response to pemphigus vulgaris IgG but not to pemphigus foliaceus autoantibodies. Erlotinib inhibited pemphigus vulgaris IgG-induced epidermal blistering and EGFR phosphorylation, loss of desmosomes, as well as ultrastructural alterations of desmosome size, plaque symmetry, and keratin filament insertion and restored the desmosome midline considered as hallmark of mature desmosomes. Erlotinib enhanced both single-molecule DSG3-binding frequency and strength and delayed DSG3 fluorescence recovery, supporting that EGFR inhibition increases DSG3 availability and cytoskeletal anchorage. Our data indicate that EGFR is a promising target for pemphigus therapy owing to its link to several signaling pathways known to be involved in pemphigus pathogenesis., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

During differentiation, keratinocytes acquire a strong, hyper-adhesive state, where desmosomal cadherins interact calcium ion independently. Previous data indicate that hyper-adhesion protects keratinocytes from pemphigus vulgaris autoantibody-induced loss of intercellular adhesion, although the underlying mechanism remains to be elucidated. Thus, in this study, we investigated the effect of hyper-adhesion on pemphigus vulgaris autoantibody-induced direct inhibition of desmoglein (DSG) 3 interactions by atomic force microscopy. Hyper-adhesion abolished loss of intercellular adhesion and corresponding morphological changes of all pathogenic antibodies used. Pemphigus autoantibodies putatively targeting several parts of the DSG3 extracellular domain and 2G4, targeting a membrane-proximal domain of DSG3, induced direct inhibition of DSG3 interactions only in non-hyper-adhesive keratinocytes. In contrast, AK23, targeting the N-terminal extracellular domain 1 of DSG3, caused direct inhibition under both adhesive states. However, antibody binding to desmosomal cadherins was not different between the distinct pathogenic antibodies used and was not changed during acquisition of hyper-adhesion. In addition, heterophilic DSC3-DSG3 and DSG2-DSG3 interactions did not cause reduced susceptibility to direct inhibition under hyper-adhesive condition in wild-type keratinocytes. Taken together, the data suggest that hyper-adhesion reduces susceptibility to autoantibody-induced direct inhibition in dependency on autoantibody-targeted extracellular domain but also demonstrate that further mechanisms are required for the protective effect of desmosomal hyper-adhesion in pemphigus vulgaris., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: This article summarizes a global study of the effect of the COVID-19 pandemic on junior health professions students' outlook on medicine. The pandemic has significantly affected health professions education. There is limited understanding of how students' pandemic experiences will affect them, and what impact these events may have on their career paths or the future of the professions. This information is important as it impacts the future of medicine., Methods: In the Fall 2020 semester, 219 health professions students at 14 medical universities worldwide responded to the question: 'Has this experience (with COVID-19) changed your outlook on medicine as a profession?'. Short essay responses were semantically coded and organized into themes and subthemes using an inductive approach to thematic analysis., Results: 145 responses were submitted. Themes were identified: (1) students reflected on the interaction between politics and healthcare; (2) reported becoming more aware of the societal expectations placed on healthcare professionals, including undertaking high risks and the sacrifices that healthcare professionals must make; (3) found reassurance from the recognized importance of healthcare professionals and expressed pride to be entering the profession; and (4) reflected on the current state of healthcare, including its limitations and future., Conclusion: Most students, independent of the extent of the pandemic in their respective countries, noted a change in their outlook regarding medicine. An overall positive outlook was noted in most junior students. Educators need to work on nurturing these sentiments and attitudes to help young students maintain a healthy relationship towards their chosen profession.

Follicular lymphoma (FL) is the most common indolent B-cell non-Hodgkin lymphoma. Circulating lymphoma (CL) cells can be seen at diagnosis in some FL patients, however, previous studies evaluating this have shown mixed results. Therefore, we sought to evaluate the impact of CL at diagnosis on outcomes in patients with newly diagnosed FL using data from a single center. Patients were divided into CL+ and CL- based on immunophenotyping via peripheral blood (PB) flow cytometry. CL was defined as detectable clonally restricted B-cells that matched the actual or expected B-cell immunophenotype of FL. The primary endpoint was progression-free survival (PFS) after first-line treatment and secondary endpoints included overall response rate (ORR), overall survival (OS), diagnosis to treatment interval (DTI), progression of disease within 2 years of diagnosis (POD24), and cumulative incidence of transformation between the two groups. Among the 541 patients with FL, 204 had PB flow cytometry performed at diagnosis, and after excluding patients not meeting the eligibility criteria, 147 cases remained with 24 (16%) CL+ at diagnosis. Patients in the CL+ group were younger (53 vs. 58 years, p = 0.02), had more extranodal involvement (83% vs. 44%, p < 0.01), follicular lymphoma international prognostic index 3-5 (55% vs. 31%, p = 0.01), and a higher proportion received first-line immunochemotherapy (75% vs. 43%, p = 0.01) compared to the CL-group. The median PFS was not significantly different between CL+ (6.27 years, 95% CI = 3.61-NR) and CL- (6.61 years, 95% CI = 5.10-9.82) cohorts regardless of the first-line treatment or level of absolute PB CL cells. There was no significant difference in ORR, median OS, DTI, POD24, and cumulative incidence of transformation between the two groups. In our study, we found that the presence of CL cells at diagnosis in FL in the contemporary era did not impact outcomes and survival., (© 2024 John Wiley & Sons Ltd.)

Sixteen cycles of Brentuximab vedotin (BV) after autologous stem cell transplant (ASCT) in high-risk relapsed/refractory classical Hodgkin lymphoma demonstrated an improved 2-year progression-free survival (PFS) over placebo. However, most patients are unable to complete all 16 cycles at full dose due to toxicity. This retrospective, multicenter study investigated the effect of cumulative maintenance BV dose on 2-year PFS. Data were collected from patients who received at least one cycle of BV maintenance after ASCT with one of the following high-risk features: primary refractory disease (PRD), extra-nodal disease (END), or relapse <12 months (RL<12) from the end of frontline therapy. Cohort 1 had patients with >75% of the planned total cumulative dose, cohort 2 with 51-75% of dose, and cohort 3 with ≤50% of dose. The primary outcome was 2-year PFS. A total of 118 patients were included. Fifty percent had PRD, 29% had RL<12, and 39% had END. Forty-four percent of patients had prior exposure to BV and 65% were in complete remission before ASCT. Only 14% of patients received the full planned BV dose. Sixty-one percent of patients discontinued maintenance early and majority of those (72%) were due to toxicity. The 2-year PFS for the entire population was 80.7%. The 2-year PFS was 89.2% for cohort 1 (n=39), 86.2% for cohort 2 (n=33), and 77.9% for cohort 3 (n=46) (P=0.70). These data are reassuring for patients who require dose reductions or discontinuation to manage toxicity.

Background: After George Floyd's murder in 2020, the Center for Disease Control and Prevention (CDC) called systemic racism a public health crisis. This health crisis is connected to the already-documented racial and socioeconomic disparities in cancer care. Ensuring hematologists and oncologists are aware of these disparities through their medical education can help to address these disparities., Methods: The authors implemented a healthcare disparities-focused curriculum in a Hematology/Oncology fellowship program during the 2020-2021 academic year at The Ohio State University Hematology/Oncology Fellowship Program. They implemented a pre- and post- survey to evaluate the efficacy of the program., Results: Fifteen fellows completed the pre-curriculum survey and 14 completed the post-survey. Before the curriculum, 12 fellows (80%) noted a "Fair" or "Good" understanding of healthcare disparities, and 6 (40%) had a "Fair" understanding of disparities in clinical trials and access to novel therapies. Fourteen fellows (93.3%) had not previously participated in a research project focused on identifying or overcoming healthcare disparities. After the curriculum, 12 (85%) fellows strongly agreed or agreed that the information presented in the curriculum was useful for training as a hematologist/oncologist. Twelve fellows (85%) noted "Agree" or "Strongly Agree" that the information presented was relevant to their practice. Eleven fellows (92%) noted that they plan to incorporate healthcare disparities into a future research or clinical project. The majority of fellows, 11 (79%) recommended that the fellowship program continue to have a formal health disparities curriculum in the future., Discussion/conclusion: There is utility in incorporating cancer disparities education into a hematology/oncology academic curriculum. We recommend further analysis of such curricula to improve fellowship education and patient outcomes with these interventions., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Regulation of cadherin-mediated cell adhesion is crucial not only for maintaining tissue integrity and barrier function in the endothelium and epithelium but also for electromechanical coupling within the myocardium. Therefore, loss of cadherin-mediated adhesion causes various disorders, including vascular inflammation and desmosome-related diseases such as the autoimmune blistering skin dermatosis pemphigus and arrhythmogenic cardiomyopathy. Mechanisms regulating cadherin-mediated binding contribute to the pathogenesis of diseases and may also be used as therapeutic targets. Over the last 30 years, cyclic adenosine 3',5'-monophosphate (cAMP) has emerged as one of the master regulators of cell adhesion in endothelium and, more recently, also in epithelial cells as well as in cardiomyocytes. A broad spectrum of experimental models from vascular physiology and cell biology applied by different generations of researchers provided evidence that not only cadherins of endothelial adherens junctions (AJ) but also desmosomal contacts in keratinocytes and the cardiomyocyte intercalated discs are central targets in this scenario. The molecular mechanisms involve protein kinase A- and exchange protein directly activated by cAMP-mediated regulation of Rho family GTPases and S665 phosphorylation of the AJ and desmosome adaptor protein plakoglobin. In line with this, phosphodiesterase 4 inhibitors such as apremilast have been proposed as a therapeutic strategy to stabilize cadherin-mediated adhesion in pemphigus and may also be effective to treat other disorders where cadherin-mediated binding is compromised., (© 2023 The Authors. Acta Physiologica published by John Wiley & Sons Ltd on behalf of Scandinavian Physiological Society.)

Chimeric antigen receptor T-cell therapy (CART) has extended survival of patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL). However, limited durability of response and prevalent toxicities remain problematic. Identifying patients who are at high risk of disease progression, toxicity, and death would inform treatment decisions. Although the cumulative illness rating scale (CIRS) has been shown to correlate with survival in B-cell malignancies, no prognostic score has been independently validated in CART recipients. We retrospectively identified 577 patients with relapsed/refractory DLBCL indicated for CART at 9 academic centers to form a learning cohort (LC). Random survival forest modeling of overall survival (OS) and progression-free survival (PFS) was performed to determine the most influential CIRS organ systems and severity grades. The presence of a severe comorbidity (CIRS score ≥ 3) in the respiratory, upper gastrointestinal, hepatic, or renal system, herein termed "Severe4," had the greatest impact on post-CART survival. Controlling for other prognostic factors (number of prior therapies, Eastern Cooperative Oncology Group performance status, BCL6 translocation, and molecular subtype), Severe4 was strongly associated with shorter PFS and OS in the LC and in an independent single-center validation cohort (VC). Severe4 was also a significant predictor of grade ≥3 cytokine release syndrome in the LC, while maintaining this trend in the VC. Thus, our results indicate that adverse outcomes for patients with DLBCL meant to receive CART can be predicted using a simplified CIRS-derived comorbidity index., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Most patients receiving chimeric antigen receptor T-cell therapy (CAR-T) for aggressive B-cell non-Hodgkin lymphoma (B-NHL) do not experience a durable remission. Several novel agents are approved to treat relapsed, refractory aggressive B-NHL; however, it remains unclear how to sequence these therapies pre- and post-CAR-T. We conducted a multicenter retrospective analysis to describe peri-CAR-T practice patterns and survival predictors for patients receiving CD19-directed CAR-T. Patients (n = 514) from 13 centers treated with CAR-T for B-NHL between 2015-2021 were included in the study. Survival curves were constructed using Kaplan-Meier method. Multivariate Cox regression analysis was used to determine the impact of the variables on survival outcomes. For all patients receiving CAR-T, a greater number of lines of therapy pre-CAR-T apheresis and bridging therapy were predictive of inferior progression-free survival (PFS) and overall survival (OS). The median PFS and OS from the time of CAR-T cell infusion were 7.6 and 25.6 months, respectively. From the time of progression post-CAR-T, the median OS was 5.5 months. The median PFS of treatments administered in the first-line post-CAR-T failure was 2.8 months. Patients with refractory disease on day 30 had inferior OS and were less likely to receive subsequent treatment(s) than other patients with CAR-T failure. Allogeneic hematopoietic cell transplantation for selected patients at any time following CAR-T failure led to durable responses in over half of patients at 1 year. These data provide a benchmark for future clinical trials in patients with post-CAR-T cell progression, which remains an unmet clinical need., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Pemphigus vulgaris is a life-threatening blistering skin disease caused by autoantibodies destabilizing desmosomal adhesion. Current therapies focus on suppression of autoantibody formation and thus treatments directly stabilizing keratinocyte adhesion would fulfill an unmet medical need. We here demonstrate that apremilast, a phosphodiesterase 4 inhibitor used in psoriasis, prevents skin blistering in pemphigus vulgaris. Apremilast abrogates pemphigus autoantibody-induced loss of keratinocyte cohesion in ex-vivo human epidermis, cultured keratinocytes in vitro and in vivo in mice. In parallel, apremilast inhibits keratin retraction as well as desmosome splitting, induces phosphorylation of plakoglobin at serine 665 and desmoplakin assembly into desmosomal plaques. We established a plakoglobin phospho-deficient mouse model that reveals fragile epidermis with altered organization of keratin filaments and desmosomal cadherins. In keratinocytes derived from these mice, intercellular adhesion is impaired and not rescued by apremilast. These data identify an unreported mechanism of desmosome regulation and propose that apremilast stabilizes keratinocyte adhesion and is protective in pemphigus., (© 2023. The Author(s).)

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a potentially curative treatment for many hematological disorders, but is often complicated by relapse of the underlying disease, graft-versus-host disease (GVHD), and infectious complications. We conducted a retrospective analysis on patients undergoing allo-SCT from 1984 to 2018 to better understand how survival has changed longitudinally with therapeutic advancements made to mitigate these complications. Method: We analyzed data from 1943 consecutive patients who received allo-SCT. Patients were divided into groups (gps) based on the year (yr) of transplant. Primary endpoints were overall survival (OS), progression free survival (PFS), and GVHD-free relapse-free survival (GRFS). Secondary endpoints were the cumulative incidences of grade II−IV and grade III−IV acute GVHD (aGVHD), chronic GVHD (cGVHD), and non-relapse mortality (NRM). Results: Our study found statistically significant improvements in OS, PFS, and GRFS. Five-year PFS among the groups increased from 24% to 48% over the years. Five-year OS increased from 25% to 53%. Five-year GRFS significantly increased from 6% to 14%, but remained relatively unchanged from 2004 to 2018. Cumulative incidences of grade II−IV aGVHD increased since 2009 (p < 0.001). However, cumulative incidence of NRM decreased since 2004 (p < 0.001). Conclusions: Our data show improved OS, PFS, and GRFS post allo-SCT over decades. This may be attributed to advances in supportive care and treatments focused on mitigation of GVHD and relapse.

Purpose of Review: Richter's transformation (RT) occurs when chronic (CLL) transforms into an aggressive lymphoma. Despite improvements in the treatment of CLL, prognosis for RT remains poor. Here, we review current literature of RT, with a focus on novel treatment options., Recent Findings: Efforts are underway to improve outcomes for patients with RT. While small molecule inhibitors have limited efficacy as monotherapy, recent developments combining them with chemo-immunotherapy show promise. Studies exploring the use of cellular therapies including chimeric antigen receptor T-cells and bispecific antibodies are ongoing. The current treatment paradigm for RT is to enroll these patients on a clinical trial when available, together with consultation for a consolidative allogeneic stem cell transplant. Trials investigating novel combinations and cellular therapy are ongoing. Determining predictive variables of transformation is imperative to design studies that allow for early identification and intervention for patients with RT., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The severe autoimmune blistering disease Pemphigus vulgaris (PV) is mainly caused by autoantibodies (IgG) against desmoglein (Dsg) 3 and Dsg1. The mechanisms leading to the development of blisters are not fully understood, but intracellular signaling seems to play an important role. Sheddases ADAM10 and ADAM17 are involved in the turnover of the desmosomal cadherin Dsg2 and ADAM10 has been shown to contribute to acantholysis in a murine pemphigus model. In the present study, we further examined the role of ADAM10 and ADAM17 both in keratinocyte adhesion and in the pathogenesis of PV. First, we found that inhibition of ADAM10 enhanced adhesion of primary human keratinocytes but not of immortalized keratinocytes. In dissociation assays, inhibition of ADAM10 shifted keratinocyte adhesion towards a hyperadhesive state. However, ADAM inhibition did neither modulate protein levels of Dsg1 and Dsg3 nor activation of EGFR at Y1068 and Y845. In primary human keratinocytes, inhibition of ADAM10, but not ADAM17, reduced loss of cell adhesion and fragmentation of Dsg1 and Dsg3 immunostaining in response to a PV1-IgG from a mucocutaneous PV patient. Similarly, inhibition of ADAM10 in dissociation assay decreased fragmentation of primary keratinocytes induced by a monoclonal antibody against Dsg3 and by PV-IgG from two other patients both suffering from mucosal PV. However, such protective effect was not observed in both cultured cells and ex vivo disease models, when another mucocutaneous PV4-IgG containing more Dsg1 autoantibodies was used. Taken together, ADAM10 modulates both hyperadhesion and PV-IgG-induced loss of cell adhesion dependent on the autoantibody profile., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Kugelmann, Anders, Sigmund, Egu, Eichkorn, Yazdi, Sárdy, Hertl, Didona, Hashimoto and Waschke.)

Anti-CD19 chimeric antigen receptor T cell therapy (CAR19) represents a critical treatment modality for patients with relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL). However, the majority of patients subsequently experience disease progression following CAR19, and data are limited on assessing the best salvage regimen for these patients. This study aimed to evaluate outcomes in R/R DLBCL patients with progressive disease post-CAR19 and to assess variables that predict response to salvage therapy. We performed a retrospective analysis of all patients with DLBCL who received CAR19 at our institution between January 2018 and February 2021, collecting data on demographic characteristics, disease characteristics, best response to CAR19, date of relapse or progression, and first salvage therapy and response to salvage. We analyzed patients according to whether they responded to CAR19 (responders) or did not (nonresponders). Salvage regimens were classified into 6 groups for analysis. Primary endpoints included overall survival (OS) and progression-free survival (PFS), calculated using the Kaplan-Meier method. Cox models were fit to evaluate the effect of prognostic factors. Among the 120 patients who received CAR19 during the analysis period were 69 responders who achieved a complete or partial response to CAR19 and 51 nonresponders, including 44 with stable or progressive disease and 7 who died before assessment. Thirty responders relapsed and 26 received salvage therapy, and 24 nonresponders received salvage therapy. The primary salvage regimens included lenalidomide-based regimens (n = 17; 34%), BTKi (n = 10; 20%), checkpoint inhibitor-based (n = 7; 14%), chemo-immunotherapy (n = 5; 10%), allogeneic hematopoietic stem cell transplantation (n = 5; 10%), and others (n = 6; 12%). There was no significant difference in OS based on salvage regimen (P = .4545). Responders who received salvage therapy had significantly longer OS than nonresponders (median OS not reached versus 10.9 months; P = .0187), and response to CAR19 and elevated lactate dehydrogenase level at time of salvage treatment were the only two statistically significant prognostic factors after accounting for other variables. Responders to CAR19 had significantly better outcomes with salvage therapy compared with nonresponders to CAR19. There was no significant difference in outcomes based on salvage regimen. Future research is needed to assess the best salvage regimen post-CAR19 failure., (Copyright © 2022 The American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Pemphigus vulgaris (PV) is a severe autoimmune blistering skin disease caused primarily by autoantibodies (PV-IgG) against the desmosomal cadherins desmoglein (Dsg) 1 and Dsg 3. Pemphigus is a model disease to study desmosome regulation because patient lesions are characterized by ultrastructural hallmarks including loss, shrinkage and splitting of desmosomes as well as by retraction of keratin filaments. The mechanisms underlying the disease are not completely understood but involve several intracellular signaling pathways triggered by autoantibody binding. Recently, we demonstrated that Phosphoinositid-Phospholipase C (PLC) and Ca 2+ signaling are required for acantholysis in human epidermis. Here, we used transmission electron microscopy to characterize the role of PLC and Ca 2+ signaling with regard to the pathogenic effects of PV-IgG on desmosome ultrastructure in human ex vivo skin model. First, we observed that the PV-IgG used in this study significantly reduced desmosome length and caused uncoupling of desmosomes from keratin filaments. Moreover, PV-IgG enhanced the number of split desmosomes but did not cause a significant loss of desmosomes. We found that inhibition of PLC and Ca 2+ signaling significantly blocked keratin filament uncoupling but not shrinkage of desmosomes. Blocking Ca 2+ flux prevented desmosome splitting. The ultrastructural analysis revealed that for preventing skin blistering it is sufficient to enhance keratin filament insertion, which is regulated by PLC/ Ca 2+ . Here, we underscore the unique role of electron microscopy to investigate the underlying mechanisms by which a signaling pathway regulates desmosome ultrastructure in pemphigus., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier GmbH.)

Background: Allogeneic hematopoietic stem cell transplant (allo-HCT) is a potential curative therapy for a variety of hematologic disorders. However, it requires highly specialized care that is only available at select centers across the country. Thus, minority populations are at risk for healthcare disparities in access to and outcomes of allo-HCT. Our study aimed to assess the impact of race and location of residence on outcomes of allo-HCT., Methods: We performed a retrospective analysis of all patients who underwent allo-HCT at the Ohio State University from 1984 to 2018. Patients were divided by race (Caucasian, African American, and other) and grouped by zip code into rural, suburban, and urban groups. Primary endpoints included progression-free survival (PFS) and overall survival (OS)., Results: Of the 1,943 patients included in the study, 94.3% self-identified as Caucasian, 4.6% African American, and 1.1% other. In total, 63.4% lived in rural areas, 22.9% suburban, and 13.8% urban. There was no significant difference in OS or PFS by race ( p  = 0.15, 0.21) or place of residence ( p  = 0.39, 0.17). In addition, no difference in nonrelapse mortality, acute and chronic graft-versus-host disease (GVHD), and GVHD-free relapse-free survival (GRFS) was seen among the race or place of residence., Conclusion: Our study suggests that when appropriate access to HCT is given, there is no difference in outcomes based on race, ethnicity or place of primary residence. Further research is needed to further evaluate barriers for these patients to undergo transplant and help mitigate these barriers., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Sigmund, Zhao, Jiang, Elder, Benson, Rosko, Bumma, Khan, Devarakonda, Vasu, Jaglowski, Mims, Choe, Larkin, Brammer, Wall, Grieselhuber, Saad, Penza, Efebera and Sharma.)

Background: Medical and dental students' feelings and thoughts about the topic of death and life's passing are often associated with learning in the gross anatomy course, when students begin working with a deceased body donor in order to study human anatomy. Little is known of whether the format of anatomy teaching has an impact on these experiences. An observational study was performed to capture the initiation of students' sentiments on the topic of life's passing during the anatomy course at 14 international universities, identify common themes regarding these thoughts, and to study the connection to variations in anatomy course formats and included elements., Method: Preclinical anatomy students reflected on one question (i.e., "How did your experience in the anatomy laboratory bring about your reflections on the meaning of life and human existence as well as the sanctity of one's passing?"). Written assignments were collected and anonymously coded. Information on anatomy courses was obtained via faculty questionnaires., Result: A variety of themes were identified at the different schools, correlated with different anatomy formats and elements. Results indicate that the courses that offer hands-on cadaveric dissections may play an important role in triggering these sentiments., Discussion: The initiation of students' sentiments about the topic of death varies and includes several themes. There can be a connection to the way anatomy is taught, particularly if hands-on comprehensive cadaveric dissection or prosections are included., Conclusion: In summary, anatomy courses can initiate students' thinking about life's passing - particularly in schools that offer hands-on cadaveric dissections or prosections., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Background: Pemphigus is a severe bullous autoimmune skin disease. Pemphigus foliaceus (PF) is characterized by antidesmoglein (Dsg) 1 IgG causing epidermal blistering; mucosal pemphigus vulgaris (mPV) by anti-Dsg3 IgG inducing erosions in the mucosa; and mucocutaneous pemphigus vulgaris (PV) by affecting both, with autoantibodies targeting Dsg1 and Dsg3., Objectives: To characterize the Ca 2+ flux pathway and delineate its importance in pemphigus pathogenesis and clinical phenotypes caused by different antibody profiles., Methods: Immunoprecipitation, Ca 2+ flux analysis, Western blotting, immunofluorescence staining, dissociation assays and a human skin ex vivo model were used., Results: PV IgG and PF IgG, but neither Dsg3-specific monoclonal antibody (AK23) nor mPV IgG, caused Ca 2+ influx in primary human keratinocytes. Phosphatidylinositol 4-kinase α interacts with Dsg1 but not with Dsg3. Its downstream target - phospholipase-C-γ1 (PLC) - was activated by PV IgG and PF IgG but not AK23 or mPV IgG. PLC releases inositol 1,4,5-trisphosphate (IP3) causing IP3 receptor (IP3R) activation and Ca 2+ flux from the endoplasmic reticulum into the cytosol, which stimulates Ca 2+ release-activated channels (CRAC)-mediated Ca 2+ influx. Inhibitors against PLC, IP3R and CRAC effectively blocked PV IgG and PF IgG-induced Ca 2+ influx; ameliorated alterations of Dsg1 and Dsg3 localization, and reorganization of keratin and actin filaments; and inhibited loss of cell adhesion in vitro. Finally, inhibiting PLC or IP3R was protective against PV IgG-induced blister formation and redistribution of Dsg1 and Dsg3 in human skin ex vivo., Conclusions: Ca 2+ -mediated signalling is important for epidermal blistering and dependent on the autoantibody profile, which indicates different roles for signalling complexes organized by Dsg1 and Dsg3. Interfering with PLC and Ca 2+ signalling may be a promising approach to treat epidermal manifestations of pemphigus., (© 2021 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.)

Allogeneic hematopoietic cell transplantation (allo-HCT) from a haploidentical (haplo) donor has emerged as a suitable alternative in the absence of a matched donor. However, haplo-HCT patients have a higher risk of graft-versus-host disease (GVHD). Hence, bone marrow (BM) stem cell source and post-transplant cyclophosphamide (PTCy) have been routinely used to help mitigate this. Due to ease of collection, peripheral blood (PB) stem cells are increasingly being considered for haplo-HCT. We retrospectively analyzed 74 patients (42 BM and 32 PB) who underwent haplo-HCT at Ohio State University from 2009 to 2018. Median age at transplant was 60 years (yrs) for BM and 54 yrs for PB, ( p = 0.45). There was no difference in OS ( p = 0.13) and NRM ( p = 0.75) as well as PFS ( p = 0.10) or GRFS ( p = 0.90) between the groups. The BM cohort showed a 3-year OS rate of 63% (95% confidence interval (CI): 46-76), and 3-year PFS of 49% (95% CI: 33-63). For the PB group, 3-year OS and PFS were 78% (95% CI: 59-89) and 68% (95% CI: 49-82), respectively. There were no differences in the incidence of acute GVHD (grade II-IV) ( p = 0.31) and chronic GVHD ( p = 0.18). Patients receiving BM had a significantly higher risk for relapse with relapse rates by 2 years at 36% (95% CI: 22-50) vs. 16% (95% CI: 6-31) for PB ( p = 0.03). The findings from this study suggest that PB is an excellent alternative to BM for haplo-HCT.

In pemphigus vulgaris (PV), autoantibodies directed against the desmosomal cadherin desmoglein (Dsg) 3 cause loss of intercellular adhesion. It is known that Dsg3 interactions are directly inhibited by autoantibody binding and that Dsg2 is upregulated in epidermis of PV patients. Here, we investigated whether heterophilic Dsg2-Dsg3 interactions occur and would modulate PV pathogenesis. Dsg2 was upregulated in PV patients' biopsies and in a human ex vivo pemphigus skin model. Immunoprecipitation and cell-free atomic force microscopy (AFM) experiments demonstrated heterophilic Dsg2-Dsg3 interactions. Similarly, in Dsg3-deficient keratinocytes with severely disturbed intercellular adhesion Dsg2 was upregulated in the desmosome containing fraction. AFM revealed that Dsg2-Dsg3 heterophilic interactions showed binding frequency, strength, Ca 2+ -dependency and catch-bond behavior comparable to homophilic Dsg3-Dsg3 or homophilic Dsg2-Dsg2 interactions. However, heterophilic Dsg2-Dsg3 interactions had a longer lifetime compared to homophilic Dsg2-Dsg2 interactions and PV autoantibody-induced direct inhibition was significantly less pronounced for heterophilic Dsg2-Dsg3 interactions compared to homophilic Dsg3 interactions. In contrast, a monoclonal anti-Dsg2 inhibitory antibody reduced heterophilic Dsg2-Dsg3 and homophilic Dsg2-Dsg2 binding to the same degree and further impaired intercellular adhesion in Dsg3-deficient keratinocytes. Taken together, the data demonstrate that Dsg2 undergoes heterophilic interactions with Dsg3, which may attenuate autoantibody-induced loss of keratinocyte adhesion in pemphigus., (Copyright © 2020 Sigmund, Steinert, Egu, Bayerbach, Waschke and Vielmuth.)

Intercellular adhesion of keratinocytes depends critically on desmosomes that, during maturation, acquire a hyperadhesive and thus Ca 2+ independent state. Here, we investigated the roles of desmoglein (Dsg) 3 and plakophilins (Pkps) in hyperadhesion. Atomic force microscopy single molecule force mappings revealed increased Dsg3 molecules but not Dsg1 molecules binding strength in murine keratinocytes. However, keratinocytes lacking Dsg3 or Pkp1 or 3 revealed reduced Ca 2+ independency. In addition, Pkp1- or 3-deficient keratinocytes did not exhibit changes in Dsg3 binding on the molecular level. Further, wild-type keratinocytes showed increased levels of Dsg3 oligomers during acquisition of hyperadhesion, and Pkp1 deficiency abolished the formation of Ca 2+ independent Dsg3 oligomers. In concordance, immunostaining for Dsg1 but not for Dsg3 was reduced after 24 h of Ca 2+ chelation in an ex vivo human skin model, suggesting that desmosomal cadherins may have different roles during acquisition of hyperadhesion. Taken together, these data indicate that hyperadhesion may not be a state acquired by entire desmosomes but rather is paralleled by enhanced binding of specific Dsg isoforms such as Dsg3, a process for which plaque proteins including Pkp 1 and 3 are required as well., (Copyright © 2020 Biophysical Society. Published by Elsevier Inc. All rights reserved.)

Acute myeloid leukemia (AML) with myelodysplasia-related changes (AML-MRC) is a distinct biologic subtype of AML that represents 25-34% of all AML diagnoses and associates with especially inferior outcomes compared to non-MRC AML. Typically, patients with AML-MRC experience low remission rates following intensive chemotherapy and a median overall survival of merely 9-12 months. In light of these discouraging outcomes, it has become evident that more effective therapies are needed for patients with AML-MRC. Liposomal daunorubicin-cytarabine (CPX-351) was approved in 2017 for adults with newly diagnosed AML-MRC and those with therapy-related AML (t-AML), and remains the only therapy specifically approved for this patient population. Other studies have also demonstrated the efficacy of the hypomethylating agent (HMA) azacitidine as upfront therapy for AML-MRC patients, which, to date, is the most common treatment employed for patients unable to tolerate the more intensive CPX-351. HMAs and venetoclax combinations have also been evaluated, but additional studies utilizing these agents in this specific subgroup are needed before conclusions regarding their role in the therapeutic armamentarium of AML-MRC patients can be reached. Currently, many studies are ongoing in attempts to further improve outcomes in this historically ill-fated patient group.

Background: Pemphigus vulgaris (PV) is an autoimmune disease characterized by blister formation in the epidermis and oral mucosa due to loss of keratinocyte cohesion. Autoantibodies present in patients with PV (PV-IgG) are known to primarily target desmoglein (Dsg)1 and Dsg3 in desmosomes. The mucosal-dominant subtype of PV (mdPV) is caused by PV-IgG autoantibodies against the cadherin-type adhesion molecule Dsg3. p38 mitogen-activated protein kinase (p38MAPK) signalling has been characterized as an important pathway downstream of PV-IgG binding and its inhibition is protective in ex vivo human skin. However, the role of p38MAPK signalling in mdPV is unknown as no experimental model has been available., Objectives: To establish a human ex vivo oral mucosa culture, and evaluate the p38MAPK dependency of blister formation and of ultrastructural alterations of desmosomes induced by mdPV-IgG., Methods: Human labial mucosa was injected with mdPV-IgG as well as AK23, a pathogenic mouse monoclonal Dsg3 antibody, in the presence or absence of p38MAPK inhibitors. Viability was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and apoptosis by terminal deoxynucleotidyl transferase dUTP nick-end labelling assay. Blister score was determined following haematoxylin and eosin staining and Dsg3 distribution by immunostaining. Samples were processed for transmission electron microscopy to analyse desmosome ultrastructure., Results: Both AK23 and mdPV-IgG induced blisters and caused reduction in desmosome size and number in labial mucosa. Inhibition of p38MAPK was not effective in preventing these alterations., Conclusions: In contrast with human epidermis, PV-IgG and AK23 induce blisters and desmosome ultrastructural changes in labial mucosa via a mechanism not dependent on p38MAPK. What's already known about this topic? Pemphigus vulgaris IgG (PV-IgG) induces blistering as well as a reduction in desmosome number and size mediated by p38 mitogen-activated protein kinase (p38MAPK) signalling in ex vivo human skin. What does this study add? This study establishes a new human ex vivo mucosa model to test pathomechanisms mediated by PV-IgG. The study demonstrates that both AK23 and mucosal-dominant PV induce blisters and associated ultrastructural changes in labial mucosa via a mechanism not dependent on p38MAPK signalling. What is the translational message? This study highlights the respective tissue-specific responses of oral mucosa and skin related to PV pathogenesis, similar to the patient situation., (© 2019 British Association of Dermatologists.)

Toll-like receptor (TLR) 13 and TLR2 are the major sensors of Gram-positive bacteria in mice. TLR13 recognizes Sa19, a specific 23S ribosomal (r) RNA-derived fragment and bacterial modification of Sa19 ablates binding to TLR13, and to antibiotics such as erythromycin. Similarly, RNase A-treated Staphylococcus aureus activate human peripheral blood mononuclear cells (PBMCs) only via TLR2, implying single-stranded (ss) RNA as major stimulant. Here, we identify human TLR8 as functional TLR13 equivalent that promiscuously senses ssRNA. Accordingly, Sa19 and mitochondrial (mt) 16S rRNA sequence-derived oligoribonucleotides (ORNs) stimulate PBMCs in a MyD88-dependent manner. These ORNs, as well as S. aureus-, Escherichia coli-, and mt-RNA, also activate differentiated human monocytoid THP-1 cells, provided they express TLR8. Moreover, Unc93b1(-/-)- and Tlr8(-/-)-THP-1 cells are refractory, while endogenous and ectopically expressed TLR8 confers responsiveness in a UR/URR RNA ligand consensus motif-dependent manner. If TLR8 function is inhibited by suppression of lysosomal function, antibiotic treatment efficiently blocks bacteria-driven inflammatory responses in infected human whole blood cultures. Sepsis therapy might thus benefit from interfering with TLR8 function., (© 2015 The Authors. Published under the terms of the CC BY NC ND 4.0 license.)

Immune stimulatory pathogen associated molecular patterns (PAMPs) are major drivers of infection pathology. Infections with Gram-negative bacteria or negatively polar and single stranded RNA influenza virus are prominent causes of morbidity and mortality. Toll-like receptor (TLR) 4 is a major host sensor for both of the two infections. In order to inhibit TLR4 driven immune activation we recently developed synthetic tetra-acylated lipid A mimetics based on a conformationally restricted βGlcN(1↔1)αGlcN disaccharide scaffold (DA-compounds) that antagonized ectopically overexpressed human and murine TLR4/MD-2 complexes. Here we comparatively analyzed human peripheral blood mononuclear cell (hPBMC) and murine bone marrow derived macrophage (mBM) activation upon 30 min of preincubation in vitro with six variably acylated DA-compounds. 16 h subsequent to consequent LPS challenge, we sampled culture supernatants for cytokine and NO concentration analysis. Four compounds significantly inhibited release of both TNF and IL-6 by hPBMCs upon LPS challenge. In contrast, three compounds effectively inhibited mBM production of MIP-2 and KC, and even five of them inhibited IL-6 and NO production. LPS driven like other TLR ligand driven mBM TNF release was largely unimpaired. The inhibitory effect was specific in that Clo75 driven cytokine release by both hPBMCs and mBMs was unimpaired by the compounds analyzed. Our results indicate biological species specificity of LPS antagonism by variably tetraacylated lipid A mimetics and validate three out of six DA-antagonists as promising candidates for development of therapeutically applicable anti-inflammatory compounds., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: Pathogen recognition drives host defense towards viral infections. Specific groups rather than single members of the protein family of pattern recognition receptors (PRRs) such as membrane spanning Toll-like receptors (TLRs) and cytosolic helicases might mediate sensing of replication intermediates of a specific virus species. TLR7 mediates host sensing of retroviruses and could significantly influence retrovirus-specific antibody responses. However, the origin of efficient cell-mediated immunity towards retroviruses is unknown. Double-stranded RNA intermediates produced during retroviral replication are good candidates for immune stimulatory viral products. Thus, we considered TLR3 as primer of cell-mediated immunity against retroviruses in vivo., Results: Infection of mice deficient in TLR3 (TLR3(-/-)) with Friend retrovirus (FV) complex revealed higher viral loads during acute retroviral infection compared to wild type mice. TLR3(-/-) mice exhibited significantly lower expression levels of type I interferons (IFNs) and IFN-stimulated genes like Pkr or Ifi44, as well as reduced numbers of activated myeloid dendritic cells (DCs) (CD86(+) and MHC-II(+)). DCs generated from FV-infected TLR3(-/-) mice were less capable of priming virus-specific CD8(+) T cell proliferation. Moreover, cytotoxicity of natural killer (NK) cells as well as CD8(+) T cells were reduced in vitro and in vivo, respectively, in FV-infected TLR3(-/-) mice., Conclusions: TLR3 mediates antiretroviral cytotoxic NK cell and CD8(+) T cell activity in vivo. Our findings qualify TLR3 as target of immune therapy against retroviral infections.