Physical dose validation of dynamic treatment for Gamma Knife radiosurgery.

BACKGROUND: Dynamic treatment in Gamma Knife (GK) radiosurgery systems delivers radiation continuously with couch movement, as opposed to stationary step-and-shoot treatment where radiation is paused when moving between isocenters. Previous studies have shown the potential for dynamic GK treatment to give faster treatment times and improved dose conformity and homogeneity. However, these studies focused only on computational simulations and lack physical validation. PURPOSE: This study aims conduct dynamic treatment dosimetric validation with physical experimental measurements. The experiments aim to (1) address assumptions made with computational studies, such as the validity of treating a continuous path as discretised points, (2) investigate uncertainties in translating computed plans to actual treatment, and (3) determine ideal treatment planning parameters, such as interval distance for the path discretization, collimator change limitations, and minimum isocenter treatment times. METHODS: This study uses a GK ICON treatment delivery machine, and a motion phantom custom-made to attach to the machine's mask adapter and move in 1D superior-inferior motion. Phantom positioning is first verified through comparisons against couch motion and computed doses. For dynamic treatment experiments, the phantom is moved through a program that first reads the desired treatment plan isocenters' position, time, and collimator sizes, then carries out the motion continuously while the treatment machine delivers radiation. Measurements are done with increasing levels of complexity: varying speed, varying collimator sizes, varying both speed and collimator sizes, then extends the same measurements to simulated 2D motion by combining phantom and couch motion. Dose comparisons between phantom motion radiation measurements and either couch motion measurements or dose calculations are analyzed with 2 mm/2% and 1 mm/2% gamma indices, using both local and global gamma index calculations. RESULTS: Phantom positional experiments show a high accuracy, with global gamma indices for all dose comparisons ≥ $\ge $ 99%. Discretization level to approximate continuous path as discrete points show the good dose matches with dose calculations when using 1 and 2-mm gaps. Complex 1D motion, including varying speed, collimator sizes, or both, as well as 2D motion with the same complexities, all show good dose matches with dose calculations: the scores are ≥ $\ge $ 92.0% for the strictest 1 mm/2% local gamma index calculation, ≥ $\ge $ 99.8% for 2 mm/2% local gamma index, and ≥ $\ge $ 97.0% for all global gamma indices. Five simulated 2D treatments with optimized plans scored highly as well, with all gamma index scores ≥ $\ge $ 95.3% when compared to stationary treatment, and scores ≥ $\ge $ 97.9% when compared to plan calculated dose. CONCLUSIONS: Dynamic treatment computational studies are validated, with dynamic treatment shown to be physically feasible and deliverable with high accuracy. A 2-mm discretization level in treatment planning is proposed as the best option for shorter dose calculation times while maintaining dose accuracy. Our experimental method enables dynamic treatment measurements using the existing clinical workflow, which may be replicated in other centers, and future studies may include 2D or 3D motion experiments, or planning studies to further quantify potential indication-specific benefits.

mRNA-1273 vaccinated inflammatory bowel disease patients receiving TNF inhibitors develop broad and robust SARS-CoV-2-specific CD8+ T cell responses.

SARS-CoV-2-specific CD8+ T cells recognize conserved viral peptides and in the absence of cross-reactive antibodies form an important line of protection against emerging viral variants as they ameliorate disease severity. SARS-CoV-2 mRNA vaccines induce robust spike-specific antibody and T cell responses in healthy individuals, but their effectiveness in patients with chronic immune-mediated inflammatory disorders (IMIDs) is less well defined. These patients are often treated with systemic immunosuppressants, which may negatively affect vaccine-induced immunity. Indeed, TNF inhibitor (TNFi)-treated inflammatory bowel disease (IBD) patients display reduced ability to maintain SARS-CoV-2 antibody responses post-vaccination, yet the effects on CD8+ T cells remain unclear. Here, we analyzed the impact of IBD and TNFi treatment on mRNA-1273 vaccine-induced CD8+ T cell responses compared to healthy controls in SARS-CoV-2 experienced and inexperienced patients. CD8+ T cells were analyzed for their ability to recognize 32 SARS-CoV-2-specific epitopes, restricted by 10 common HLA class I allotypes using heterotetramer combinatorial coding. This strategy allowed in-depth ex vivo profiling of the vaccine-induced CD8+ T cell responses using phenotypic and activation markers. mRNA vaccination of TNFi-treated and untreated IBD patients induced robust spike-specific CD8+ T cell responses with a predominant central memory and activated phenotype, comparable to those in healthy controls. Prominent non-spike-specific CD8+ T cell responses were observed in SARS-CoV-2 experienced donors prior to vaccination. Non-spike-specific CD8+ T cells persisted and spike-specific CD8+ T cells notably expanded after vaccination in these patient cohorts. Our data demonstrate that regardless of TNFi treatment or prior SARS-CoV-2 infection, IBD patients benefit from vaccination by inducing a robust spike-specific CD8+ T cell response.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and active cancer who also had prior bleed or prior renal disease.

OBJECTIVE: Patients with active cancer and venous thromboembolism (VTE) have elevated risk of recurrent VTE (rVTE) and major bleeding (MB). The risk is even higher within those with a prior bleeding event or renal disease. There is a need to understand the risk of rVTE and MB of commonly used anticoagulants among these high-risk patients. METHODS: VTE patients with active cancer and treated with apixaban, warfarin, or low molecular weight heparin (LMWH) within 30 days of VTE were identified from five claims databases in the United States. Inverse probability of treatment weighting (IPTW) was used to balance patient characteristics. The post-IPTW population was stratified by prior bleed or renal disease status. Cox proportional hazards models were used to evaluate interactions between treatment and prior bleed or renal disease on risk of rVTE and MB, with p value <.1 considered significant. RESULTS: Study criteria were met by 30,586 VTE cancer patients: 35.0% had prior bleed and 29.0% had renal disease. For apixaban, LMWH, and warfarin cohorts, the incidence (events per 100 person-years) of MB was higher in patients with prior bleed (17.48 vs 7.58, 25.61 vs 13.11, and 20.38 vs 8.97) or renal disease (15.79 vs 8.71, 22.11 vs 15.90, and 18.49 vs 10.39) vs those without the conditions. Generally, there were no significant interactions between anticoagulant use and prior bleed or renal disease on rVTE and MB (p for interaction >.1). CONCLUSION: The incidence of MB was higher among those with prior bleed or renal disease. Effects of apixaban, warfarin, or LMWH were generally consistent regardless of prior bleed or renal disease status.

Payer approval and rejection of oral anticoagulant prescriptions and prescription abandonment patterns among patients with venous thromboembolism.

BACKGROUND: Venous thromboembolism (VTE) is a major public health condition that renders patients at risk of recurrent events, which significantly increases their morbidity, mortality, and health care costs. Apart from warfarin, direct oral anticoagulants, such as apixaban, dabigatran, or rivaroxaban, are approved for VTE treatment. Cardiovascular drugs are largely impacted by formulary restrictions; however, the impact on oral anticoagulants (including warfarin and direct oral anticoagulants) in VTE has not been well studied. OBJECTIVE: To describe the extent of payer-rejected claims for oral anticoagulants for VTE and the factors associated with rejected claims. Prescription abandonment of oral anticoagulants and the time to an eventual fill for oral anticoagulant after rejection or abandonment were also evaluated. METHODS: A retrospective cohort study was conducted among patients with VTE newly prescribed an oral anticoagulant (first claim was the index) between October 2016 and October 2021. Descriptive statistics were used to describe the proportion of patients with paid (ie, filled), rejected, or abandoned index oral anticoagulant prescription and journey to paid prescription among those with initial rejection. Multivariable logistic regression was used to identify factors associated with initial rejection. RESULTS: Among the overall sample (N = 297,312), 74.3% had initial oral anticoagulant prescriptions approved, 9.1% had them rejected, and 16.7% abandoned them. Of the patients with initial rejection, 82.1% eventually filled their oral anticoagulant prescriptions; however, for 14.2% of these patients, the first fill was for an oral anticoagulant other than that initially prescribed. The mean time to a first fill for an oral anticoagulant after an initial rejection was 18.3 days. More than half of the patients with an initial rejected oral anticoagulant claim had at least 1 additional rejection during the follow-up period. Of the patients who abandoned their initial oral anticoagulant prescription, 83.9% filled an oral anticoagulant prescription during follow-up; the mean time to fill for the index oral anticoagulant was 15.6 days. Oral anticoagulant type, Medicare payer coverage, prescribing physician specialty, and VTE diagnosis setting of care were significantly associated with index oral anticoagulant claim rejection (P < 0.05). CONCLUSIONS: Rejection and abandonment may delay access to oral anticoagulant treatment. Factors contributing to these scenarios should be understood and addressed for proper VTE management.

Effectiveness and safety of anticoagulants among patients with venous thromboembolism and common cancers or cancers with high venous thromboembolism risk.

Aim: Treatment effects among anticoagulant-treated patients with venous thromboembolism (VTE) and cancer across tumor types were evaluated. Methods: Patients initiating an anticoagulant within 30 days after VTE were identified. After inverse probability treatment weighting, patients were stratified by tumor type. Interactions between treatment and tumor type on recurrent VTE, major bleeding and clinically relevant non-major bleeding were assessed using Cox proportional hazard models. Results: Treatment effects were generally not significantly different among patients with or without the following cancer types: prostate, breast, lung, pancreatic or multiple myeloma. Few significant interactions were observed for lung and pancreatic cancer. Conclusion: Anticoagulant treatment effects were generally consistent across tumor types. The significant interactions may indicate tumor-specific effects of anticoagulants, but further research is needed.

Complement activation drives antibody-mediated transfusion-related acute lung injury via macrophage trafficking and formation of NETs.

ABSTRACT: Transfusion-related acute lung injury (TRALI) is one of the leading causes of transfusion-related fatalities and, to date, is without available therapies. Here, we investigated the role of the complement system in TRALI. Murine anti-major histocompatibility complex class I antibodies were used in TRALI mouse models, in combination with analyses of plasma samples from patients with TRALI. We found that in vitro complement activation was related to in vivo antibody-mediated TRALI induction, which was correlated with increased macrophage trafficking from the lungs to the blood in a fragment crystallizable region (Fc)-dependent manner and that this was dependent on C5. Human immunoglobulin G 1 variants of the murine TRALI-inducing antibody 34-1-2S, either unable to activate complement and/or bind to Fcγ receptors (FcγRs), revealed an essential role for the complement system, but not for FcγRs, in the onset of 34-1-2S-mediated TRALI in mice. In addition, we found high levels of complement activation in the plasma of patients with TRALI (n = 53), which correlated with elevated neutrophil extracellular trap (NET) markers. In vitro we found that NETs could be formed in a murine, 2-hit model, mimicking TRALI with lipopolysaccharide and C5a stimulation. Collectively, this reveals a critical role of Fc-mediated complement activation in TRALI, with a direct relation to macrophage trafficking from the lungs to the blood and an association with NET formation, suggesting that targeting the complement system may be an attractive therapeutic approach for combating TRALI.

Journey to anticoagulant access following payer rejection of apixaban.

OBJECTIVES: To investigate the journey to oral anticoagulant (OAC) access following formulary-related rejection of apixaban (Eliquis) and evaluate characteristics associated with failure to achieve OAC access among patients with atrial fibrillation (AF). STUDY DESIGN: Retrospective study using the Optum Market Clarity Data from January 2016 through February 2020. METHODS: Patients had at least 1 claim rejection for apixaban due to prior authorization (PA), formulary exclusion (FE), or quantity limit (QL) and at least 1 AF diagnosis on or before the rejected claim. Descriptive statistics summarized transaction journeys by type of formulary restriction. Multivariable regression assessed patient characteristics associated with not receiving an OAC within 60 days after initial rejection. RESULTS: Among 18,434 patients in the analytic sample, QL was the most common reason for rejection (68.7%), followed by PA (21.2%) and FE (10.2%). Most patients received a paid OAC claim within 60 days after rejection (82.2%-85.5% across restriction types). Mean time from rejection to paid claim ranged from 5.2 to 10.7 days among patients with a paid OAC claim and 12.4 to 17.6 days among those with multiple attempts before OAC receipt. Characteristics associated with higher odds of not receiving OAC treatment included being male, beingAfrican American, having Medicaid coverage, possessing a high stroke risk score, exhibiting no evidence of prior apixaban treatment, and being prescribed a low dose of apixaban on the initial rejected claim. CONCLUSIONS: Most patients with a claim rejection for apixaban received approval for apixaban within 60 days, suggesting that initial rejection merely created a delay in treatment. Vulnerable populations were at greater risk of not receiving a paid OAC claim.

The Association between Direct Oral Anticoagulants Prescribing Behavior and Non-Valvular Atrial Fibrillation Outcomes: An Instrumental Variable Analysis of Real-World Data.

Several observational studies have compared apixaban with rivaroxaban in patients with non-valvular atrial fibrillation (NVAF), but these analyses may be confounded by unmeasured characteristics. This study used provider prescribing preference (PPP) as an instrumental variable (IV) to assess the association between prescriber choice of rivaroxaban vs. apixaban and the study outcomes of stroke/systemic embolism (SE), major bleeding, and death in a retrospective cohort of NVAF patients in the US. Initiators of either medication were linked to their prescribers and followed until the first of the study outcome, the end of rivaroxaban/apixaban use, or 365 days after initiation. PPP for each patient was the percent of rivaroxaban initiations issued by the provider for the prior 10 NVAF patients. Cox regression models tested associations between quintiles of PPP and each outcome. A total of 61,155 patients and 1726 providers were included. The IV was a strong predictor of rivaroxaban prescription (OR = 17.9; 95% CI: 16.6, 19.3). There were statistically significant associations between increasing preference for rivaroxaban and rates of major bleeding (ptrend = 0.041) and death (ptrend = 0.031), but not stroke/SE (ptrend = 0.398). This analysis provides evidence of the relative safety of apixaban over rivaroxaban for the risk of major bleeding and death.

Machine learning for the prediction of survival post-allogeneic hematopoietic cell transplantation: A single-center experience.

INTRODUCTION: Prediction of outcomes following allogeneic hematopoietic cell transplantation (HCT) remains a major challenge. Machine learning (ML) is a computational procedure that may facilitate the generation of HCT prediction models. We sought to investigate the prognostic potential of multiple ML algorithms when applied to a large single-center allogeneic HCT database. METHODS: Our registry included 2697 patients that underwent allogeneic HCT from January 1976 to December 2017, 45 pre-transplant baseline variables were included in the predictive assessment of each ML algorithm on overall survival (OS) as determined by area under the curve (AUC). Pre-transplant variables used in the EBMT machine learning study (Shouval et al, 2015) were used as a benchmark for comparison. RESULTS: On the entire dataset, the random forest (RF) algorithm performed best (AUC 0.71±0.04) compared to the second-best model, logistic regression (LR) (AUC=0.69±0.04) (p<0.001). Both algorithms demonstrated improved AUC scores using all 45 variables compared to the limited variables examined by the EBMT study. Survival at 100 days post-HCT using RF on the full dataset discriminated patients into different prognostic groups with different 2-year OS (p<0.0001). We then examined the ML methods that allow for significant individual variable identification, including LR and RF, and identified matched related donors (HR=0.49, p<0.0001), increasing TBI dose (HR=1.60, p=0.006), increasing recipient age (HR=1.92, p<0.0001), higher baseline Hb (HR=0.59, p=0.0002) and increased baseline FEV1 (HR=0.73, p=0.02), among others. CONCLUSION: The application of multiple ML techniques on single center allogeneic HCT databases warrants further investigation and may provide a useful tool to identify variables with prognostic potential.

Payer formulary tier increases of apixaban: how patients respond and potential implications.

OBJECTIVE: To assess potential impacts of formulary tier increases of apixaban-an efficacious oral anticoagulant (OAC) for preventing stroke in patients with atrial fibrillation (AF)-on patients' prescription drug plan (PDP) switching and OAC treatment patterns. METHODS: Nationwide claims data for Medicare beneficiaries with Parts A, B, and D (100% sample) were used to assess apixaban-treated AF patients who faced a formulary tier increase for apixaban in 2017 by their Part D PDP. Patients' out-of-pocket (OOP) costs for apixaban were described, along with PDP switching and OAC treatment patterns. RESULTS: Among 1845 included patients, 97.7% had apixaban on tier 3 of their plan's formulary in 2016 and faced its increase to tier 4 for 2017. Approximately 4% (N = 81) of patients pre-emptively switched to a different PDP for 2017 with almost all switching to plans with apixaban on a lower formulary tier and 85.2% continuing apixaban treatment. Among the 96% (N = 1764) of patients who remained on the same PDP for 2017, over half (57.5%) continued apixaban treatment, despite increased OOP costs ($54 vs. $135 for a 30-day supply in 2016 vs. 2017). Only 12.4% of those who remained on the same plan for 2017 switched to another OAC, while as much as 30.1% discontinued OACs. These discontinuers exhibited higher comorbidity burdens than patients continuing on any OAC. CONCLUSION: The majority of patients continued on apixaban despite higher OOP cost, suggesting patients' reluctance to change treatment for non-medical reasons; however, 30% of patients discontinued OAC treatment after higher apixaban tier placement.

A Real-World Evaluation of Primary Medication Nonadherence in Patients with Nonvalvular Atrial Fibrillation Prescribed Oral Anticoagulants in the United States.

BACKGROUND: Nonadherence to oral anticoagulants (OACs) is a challenge to stroke risk reduction in patients with nonvalvular atrial fibrillation (NVAF). Data on primary medication nonadherence (PMN) in NVAF are lacking. OBJECTIVES: Our aim was to assess the rates and predictors of PMN among NVAF patients who were newly prescribed an OAC. METHODS: This was a retrospective database analysis of linked healthcare claims and electronic health record data. Adult NVAF patients with a prescription order for an OAC (apixaban, rivaroxaban, dabigatran, or warfarin) between January 2016 and June 2019 were identified (date of first prescription order = index date). Patients had a 1-year baseline and a 6-month post-index period to assess the rates of PMN, defined as having a prescription order but no paid claim for any OAC on or within 30 days after the index date. Sensitivity analyses explored 60-, 90- and 180-day PMN thresholds. Logistic regression models were used to examine the predictors of PMN. RESULTS: Among 20,393 patients, the overall 30-day PMN rate was 28.4%; PMN rates decreased to 17% with a 180-day threshold. PMN was numerically lowest for warfarin among OACs and numerically lowest for apixaban among direct OACs. A CHA2DS2-VASc score of ≥ 3, commercial insurance, and African American race were associated with higher odds of PMN. CONCLUSIONS: More than one-quarter of patients experienced PMN within 30 days of their initial prescription order. This rate decreased over a longer period, suggesting a delay in fills. Understanding the factors associated with PMN is warranted to develop effective interventions for improving OAC treatment rates in NVAF.

Effectiveness and safety of anticoagulants among venous thromboembolism cancer patients with and without brain cancer.

INTRODUCTION: Patients with brain cancer are at a high risk of developing venous thromboembolism (VTE) and are underrepresented in clinical trials. This study compared the risk of recurrent VTE (rVTE), major bleeding (MB), and clinically relevant non-major bleeding (CRNMB) among VTE cancer patients initiating apixaban, low molecular weight heparin (LMWH), or warfarin stratified by patients with brain vs other cancer types. MATERIALS AND METHODS: Active cancer patients initiating apixaban, LMWH, or warfarin within 30 days after VTE diagnosis were identified from 4 US commercial and the Medicare databases. Inverse probability of treatment weights (IPTW) was used to balance patient characteristics. Cox proportional hazards models were used to evaluate the interaction between brain cancer status and treatment on outcomes (rVTE, MB, and CRNMB), with a p-value <0.1 indicating a significant interaction. RESULTS: Of 30,586 patients with active cancer (5 % had brain cancer), apixaban (vs. LMWH and warfarin) was associated with lower risk of rVTE, MB, and CRNMB. Generally, no significant interactions (P > 0.1) were found between brain cancer status and anticoagulant treatment across outcomes. The exception was MB for apixaban [vs LMWH (p-value for interaction = 0.091)] with a higher reduction among those with brain cancer (HR = 0.32) than those with (HR = 0.72) other cancer. CONCLUSIONS: Among VTE patients with all types of cancer, apixaban (vs LMWH and warfarin) was associated with a lower risk of rVTE, MB, and CRNMB. In general, anticoagulant treatment effects were not significantly different between VTE patients with brain cancer and those with other cancer.

Spatio-Temporal Clustering of Multi-Location Time Series to Model Seasonal Influenza Spread.

Although seasonal influenza disease spread is a spatio-temporal phenomenon, public surveillance systems aggregate data only spatially, and are rarely predictive. We develop a hierarchical clustering-based machine learning tool to anticipate flu spread patterns based on historical spatio-temporal flu activity, where we use historical influenza-related emergency department records as a proxy for flu prevalence. This analysis replaces conventional geographical hospital clustering with clusters based on both spatial and temporal distance between hospital flu peaks to generate a network illustrating whether flu spreads between pairs of clusters (direction) and how long that spread takes (magnitude). To overcome data sparsity, we take a model-free approach, treating hospital clusters as a fully-connected network, where arcs indicate flu transmission. We perform predictive analysis on the clusters' time series of flu ED visits to determine direction and magnitude of flu travel. Detection of recurrent spatio-temporal patterns may help policymakers and hospitals better prepare for outbreaks. We apply this tool to Ontario, Canada using a five-year historical dataset of daily flu-related ED visits, and find that in addition to expected flu spread between major cities/airport regions, we were able to illuminate previously unsuspected patterns of flu spread between non-major cities, providing new insights for public health officials. We showed that while a spatial clustering outperforms a temporal clustering in terms of the direction of the spread (81% spatial v. 71% temporal), the opposite is true in terms of the magnitude of the time lag (20% spatial v. 70% temporal).

Effectiveness and Safety of Apixaban vs Warfarin in Patients with Venous Thromboembolism with Risk Factors for Bleeding or for Recurrences.

INTRODUCTION: Patients at increased risk of bleeding and recurrent VTE who develop venous thromboembolism (VTE) present challenges for clinical management. This study evaluated the effectiveness and safety of apixaban vs warfarin in patients with VTE who have risk factors for bleeding or recurrences. METHODS: Adult patients with VTE initiating apixaban or warfarin were identified from five claims databases. Stabilized inverse probability treatment weighting (IPTW) was used to balance characteristics between cohorts for the main analysis. Subgroup interaction analyses were conducted to evaluate treatment effects among patients with and without each of the conditions that increased the risk of bleeding (thrombocytopenia and history of bleed) or recurrent VTE (thrombophilia, chronic liver disease, and immune-mediated disorders). RESULTS: A total of 94,333 warfarin and 60,786 apixaban patients with VTE met selection criteria. After IPTW, all patient characteristics were balanced between cohorts. Apixaban (vs warfarin) patients were at lower risk of recurrent VTE (HR [95% confidence interval (CI) 0.72 [0.67-0.78]), major bleeding (MB) (HR [95% CI] 0.70 [0.64-0.76]), and clinically relevant non-major (CRNM) bleeding (HR [95% CI] 0.83 [0.80-0.86]). Subgroup analyses showed generally consistent findings with the overall analysis. For most subgroup analyses, there were no significant interactions between treatment and subgroup strata on VTE, MB and CRNM bleeding. CONCLUSION: Patients with prescription fills for apixaban had lower risk of recurrent VTE, MB, and CRNM bleeding compared with warfarin patients. Treatment effects of apixaban vs warfarin were generally consistent across subgroups of patients at increased risk of bleeding/recurrences.

The added value of conventional defecography and MRI defecography in clinical decision making on treatment for posterior compartment prolapse.

INTRODUCTION AND HYPOTHESIS: Conventional defecography and MRI defecography can be requested as an additional test for diagnosing and differentiating the type of posterior compartment prolapse and/or obstructive defecation disorders. The objective of this study was to determine the added value of conventional defecography, conventional defecography and MRI defecography for clinical decision-making on treatment for patients with posterior compartment prolapse. METHODS: Four gynecologists were asked to fill in their treatment plan per patient for 32 cases for three different steps. Step 1 consisted of information on the anamnesis and physical examination (POP-Q). Step 2 consisted of Step 1, including conventional defecography (group A) or MRI defecography (group B). In Step 3, all gynecologists received the information on Step 1 including both conventional defecography and MRI defecography. Data analysis solely focused on the assessment of changes in the gynecological treatment plan of the posterior compartment. RESULTS: After Step 2 a change in treatment plan occurred in 37% and 48% of the women in groups A and B, respectively. Accordingly, after Step 3 (including all imaging data), a change in treatment plan occurred in 19% and 52% of the women in groups A and B, respectively. A change within the surgery group (when a different type of surgery was selected) was seen for a total of 11 cases in group A and 20 in group B in all steps combined. CONCLUSIONS: Both conventional defecography and MRI defecography had an large effect on the treatment plan for patients with posterior compartment prolapse. The dedicated added value of the imaging modality individually cannot be concluded yet.

Role of N-Glycosylation in FcγRIIIa interaction with IgG.

Immunoglobulins G (IgG) and their Fc gamma receptors (FcγRs) play important roles in our immune system. The conserved N-glycan in the Fc region of IgG1 impacts interaction of IgG with FcγRs and the resulting effector functions, which has led to the design of antibody therapeutics with greatly improved antibody-dependent cell cytotoxicity (ADCC) activities. Studies have suggested that also N-glycosylation of the FcγRIII affects receptor interactions with IgG, but detailed studies of the interaction of IgG1 and FcγRIIIa with distinct N-glycans have been hindered by the natural heterogeneity in N-glycosylation. In this study, we employed comprehensive genetic engineering of the N-glycosylation capacities in mammalian cell lines to express IgG1 and FcγRIIIa with different N-glycan structures to more generally explore the role of N-glycosylation in IgG1:FcγRIIIa binding interactions. We included FcγRIIIa variants of both the 158F and 158V allotypes and investigated the key N-glycan features that affected binding affinity. Our study confirms that afucosylated IgG1 has the highest binding affinity to oligomannose FcγRIIIa, a glycan structure commonly found on Asn162 on FcγRIIIa expressed by NK cells but not monocytes or recombinantly expressed FcγRIIIa.

Parallel detection of SARS-CoV-2 epitopes reveals dynamic immunodominance profiles of CD8+ T memory cells in convalescent COVID-19 donors.

Objectives: High-magnitude CD8+ T cell responses are associated with mild COVID-19 disease; however, the underlying characteristics that define CD8+ T cell-mediated protection are not well understood. The antigenic breadth and the immunodominance hierarchies of epitope-specific CD8+ T cells remain largely unexplored and are essential for the development of next-generation broad-protective vaccines. This study identified a broad spectrum of conserved SARS-CoV-2 CD8+ T cell epitopes and defined their respective immunodominance and phenotypic profiles following SARS-CoV-2 infection. Methods: CD8+ T cells from 51 convalescent COVID-19 donors were analysed for their ability to recognise 133 predicted and previously described SARS-CoV-2-derived peptides restricted by 11 common HLA class I allotypes using heterotetramer combinatorial coding, which combined with phenotypic markers allowed in-depth ex vivo profiling of CD8+ T cell responses at quantitative and phenotypic levels. Results: A comprehensive panel of 49 mostly conserved SARS-CoV-2-specific CD8+ T cell epitopes, including five newly identified low-magnitude epitopes, was established. We confirmed the immunodominance of HLA-A*01:01/ORF1ab1637-1646 and B*07:02/N105-113 and identified B*35:01/N325-333 as a third epitope with immunodominant features. The magnitude of subdominant epitope responses, including A*03:01/N361-369 and A*02:01/S269-277, depended on the donors' HLA-I context. All epitopes expressed prevalent memory phenotypes, with the highest memory frequencies in severe COVID-19 donors. Conclusion: SARS-CoV-2 infection induces a predominant CD8+ T memory response directed against a broad spectrum of conserved SARS-CoV-2 epitopes, which likely contributes to long-term protection against severe disease. The observed immunodominance hierarchy emphasises the importance of T cell epitopes derived from nonspike proteins to the overall protective and cross-reactive immune response, which could aid future vaccine strategies.

Altered Fc glycosylation of anti-HLA alloantibodies in hemato-oncological patients receiving platelet transfusions.

BACKGROUND: The formation of alloantibodies directed against class I human leukocyte antigens (HLA) continues to be a clinically challenging complication after platelet transfusions, which can lead to platelet refractoriness (PR) and occurs in approximately 5%-15% of patients with chronic platelet support. Interestingly, anti-HLA IgG levels in alloimmunized patients do not seem to predict PR, suggesting functional or qualitative differences among anti-HLA IgG. The binding of these alloantibodies to donor platelets can result in rapid clearance after transfusion, presumably via FcγR-mediated phagocytosis and/or complement activation, which both are affected by the IgG-Fc glycosylation. OBJECTIVES: To characterize the Fc glycosylation profile of anti-HLA class I antibodies formed after platelet transfusion and to investigate its effect on clinical outcome. PATIENTS/METHODS: We screened and captured anti-HLA class I antibodies (anti-HLA A2, anti-HLA A24, and anti-HLA B7) developed after platelet transfusions in hemato-oncology patients, who were included in the PREPAReS Trial. Using liquid chromatography-mass spectrometry, we analyzed the glycosylation profiles of total and anti-HLA IgG1 developed over time. Subsequently, the glycosylation data was linked to the patients' clinical information and posttransfusion increments. RESULTS: The glycosylation profile of anti-HLA antibodies was highly variable between patients. In general, Fc galactosylation and sialylation levels were elevated compared to total plasma IgG, which correlated negatively with the platelet count increment. Furthermore, high levels of afucosylation were observed for two patients. CONCLUSIONS: These differences in composition of anti-HLA Fc-glycosylation profiles could potentially explain the variation in clinical severity between patients.

Payer formulary exclusions of apixaban: how patients respond and potential implications.

In recent years, US payers have increased usage of formulary exclusions as a means to help manage costs. Earlier this year, one of the largest pharmacy benefit managers in the country added Eliquis (apixaban), the most widely used anticoagulant, to its list of excluded medicines from its formulary, raising concerns by physicians and patients. In this commentary, we examine the potential impacts of formulary exclusion of a drug like apixaban-a treatment for patients with atrial fibrillation and venous thromboembolism to help prevent stroke and clotting events and which has been demonstrated to have a strong efficacy and safety profile. We discuss the effect of formulary exclusions on patients' ability to access the most clinically appropriate treatment for their health needs, along with possible effects on their health and well-being. We also report descriptive results on apixaban-treated patients with traditional Medicare coverage who faced a formulary exclusion of apixaban in 2017, and these patients' observed behaviors. We found that the majority of these patients remained on apixaban either through pre-emptively switching to a different Part D drug plan with apixaban coverage or applying for formulary exception. Our findings suggest that formulary exclusion did not help to achieve the goal of switching patients to less costly medications but created additional hurdles for patients to access their preferred treatment and increased patient burden. Alternative ways to manage payer costs may be needed to help avoid poor outcomes and reduce the burden placed on patients in their efforts to access life-saving medications.

Risk of stroke/systemic embolism, major bleeding, and associated costs in non-valvular atrial fibrillation patients who initiated apixaban, dabigatran, or rivaroxaban compared with warfarin in the United States medicare population: updated analysis.

OBJECTIVE: To provide an updated comparison of the risk and cost of stroke/systemic embolism (SE) and major bleeding between direct oral anticoagulants (DOAC: apixaban, rivaroxaban, dabigatran) and warfarin among non-valvular atrial fibrillation (NVAF) patients. METHODS: Adults (≥65 years) initiating warfarin or DOACs between 1 January 2013 and 31 December 2014 were selected from the Medicare database and propensity scores matched 1:1 to balance baseline characteristics. Cox proportional hazards models were used to estimate the risks of stroke/SE and major bleeding of each DOAC vs. warfarin. Two-part models were used to compare the stroke/SE- and major bleeding-related medical costs in each matched cohort. RESULTS: Of the 264,479 eligible patients, 38,740 apixaban-warfarin pairs, 76,677 rivaroxaban-warfarin pairs, and 20,955 dabigatran-warfarin pairs were matched. Apixaban (Hazard Ratio [HR] = 0.46; 95% Confidence Interval [CI] 0.38-0.56) and rivaroxaban (HR = 0.71; 95% CI 0.63-0.80) were associated with a significantly lower risk of stroke/SE compared to warfarin. Apixaban (HR = 0.57; 95% CI 0.51-0.63) and dabigatran (HR = 0.80; 95% CI 0.70-0.90) were associated with a significantly lower risk of major bleeding; rivaroxaban (HR = 1.14; 95% CI 1.07-1.21) was associated with a significantly higher risk of major bleeding compared to warfarin. Compared to warfarin, apixaban and rivaroxaban had significantly lower stroke/SE-related medical costs; and apixaban and dabigatran had significantly lower major bleeding-related medical costs. CONCLUSIONS: This real-world analysis showed DOACs to be associated with a lower risk of stroke/SE and major bleeding, and lower medical costs compared to warfarin. Among them, only apixaban appears to be associated with a significantly lower risk of all three outcomes collectively: stroke/SE, major bleeding, and lower related medical costs compared to warfarin.