Cell Cutoff Research Articles

Optimal component sizing and performance of Fuel Cell – Battery powered vehicle over world harmonized and new european driving cycles

Optimal component sizing and hybridization play vital task in reducing fuel utilization, increasing fuel cell system longevity and fuel economy of fuel cell electric vehicles. This paper proposes a fuel cell-battery powered vehicle is modeled and analyzed in MATLAB/Simulink tool known as Advanced Vehicle Simulator (ADVISOR). In addition to the optimal component sizing of power source components, the new World harmonized Light Vehicle Test Cycle (WLTC) is introduced and embedded into the ADVISOR software to estimate the driving behavior of the proposed fuel cell electric vehicle (FCEV). Approximately 10.5 % more gradeability performance achieved for the proposed powertrain against benchmark fuel cell powered vehicle Moreover, the world light-duty test cycle exhibit 18.5 % more fuel cell cut–off time and 29 % less run on time when compared with new european driving cycle (NEDC) cycle. The results of this study showed better fuel cell energy efficiency in terms of Wh/mile, fuel cell on–off strategy, cold start ability, acceleration and gradeability performance over the world light-duty test cycle drive cycle against new european driving cycle.

PRAME Expression in Mucosal Melanoma of the Head and Neck Region.

PRAME (PReferentially expressed Antigen in MElanoma), a cancer-testis antigen expressed in normal and neoplastic tissues with several functions, proved to be a useful diagnostic tool in the differential diagnosis between benign and malignant melanocytic lesions. The current study aims to perform PRAME stain on a retrospective case series of mucosal melanocytic tumors of the head and neck region to compare 3 different scores and evaluate the most reliable one in this diagnostic set. Immunohistochemical analysis for PRAME was performed in 54 benign and malignant mucosal melanocytic tumors of the head and neck region collected from 41 patients. The best-performing cutoff of PRAME-positive cells (nuclear stain) to differentiate benign and malignant mucosal melanocytic tumors of the head and neck region is that proposed by Raghavan and colleagues (<60%/≥60% of PRAME-positive cells), with 100% and 77.8% of benign lesions and malignant tumors respectively correctly identified. Applying this score, PRAME stain showed the best results (sensitivity, specificity, accuracy, and positive and negative predictive values) for the diagnosis of head and neck melanocytic tumors. However, a subset of PRAME-negative malignant tumors was identified, especially located in the palatal area (hard and soft palate). Finally, high PRAME expression (≥60%) was associated with specific sites (nasal cavity/nasal septum/turbinates nasopharynx, and the maxillary sinus), nodular histotype, and female sex.

Correlation of Pyuria and Bacteriuria in Acute Care

BackgroundPyuria is often used as an import marker in the diagnosis of urinary tract infection. The interpretation of pyuria may be especially important in patients with nonspecific complaints. There is a paucity of data to demonstrate the utility of pyuria alone in the diagnosis of bacteriuria or urinary tract infection. This study aims to further define the relationship of pyuria and positive bacterial growth in urine culture, as well as the diagnostic utility of different urine white blood cell cutoff points. MethodA total of 46,127 patients older than the age of 18 were selected from the inpatient population of HCA Healthcare System Capital Division. Urine microscopy results were stratified by white blood cell count and correlated with positivity of urine culture bacterial growth. The optimal urine white blood cell cutoff was derived based on the receiver operating characteristic curve plot. ResultsUrine microscopy finding of white blood cell 0-5 cell/hpf, 5-10 cell/hpf, 10-25 cell/hpf, and higher than 25 cell/hpf was associated with 25.4%, 28.2%, 33%, and 53.8% rates of bacteriuria, respectively. The receiver operating characteristic curve plot demonstrated that pyuria alone did not provide adequate diagnostic accuracy to predict bacteriuria. The optimal cutoff point for the best combination of sensitivity and specificity was found to be 25 cell/hpf. ConclusionPyuria alone provides inadequate diagnostic accuracy for predicting bacteriuria. Urine white blood cell count greater than 25 cell/hpf was found to be the optimal cutoff to detect bacteriuria. The result of this study supports the current guideline recommendation against antibiotic treatment based on urine analysis alone. It also informs future design of randomized controlled trial that investigates interventional strategies for patients with pyuria and nonspecific complaints.

Evaluation of NKp46 expression and cytokine production of decidual NK cells in women with recurrent pregnancy loss.

PurposeNKp46, a receptor on NK cells, is involved in cytotoxicity and cytokine production. The authors aimed to evaluate the effect of NKp46 on decidual NK (dNK) cells during pregnancy and whether it can be a marker for immunological abnormalities in women with recurrent pregnancy loss (RPL).MethodsFlow‐cytometric analysis was made to assess NKp46 expression and intracellular cytokine production of dNK cells. The proportion of NKp46+ dNK cells was analyzed among RPL patients who aborted karyotypically normal pregnancies and those who either aborted karyotypically abnormal pregnancies or without genetic studies, and controls who were going through the induced abortion.ResultsThe %NKp46+ and %NKp46bright dNK cells were significantly lower in the RPL women who aborted karyotypically normal pregnancies than in the control group. The %NKp46bright dNK cells were significantly correlated with the NK1/NK2 ratio of dNK cells. The %NKp46+ dNK cell cutoff for RPL with immunological abnormalities was determined by the ROC curve analysis. In women with the low %NKp46+ dNK, NK1/NK2 ratios were significantly higher than those with the high.ConclusionRPL patients with an immunological abnormality have decreased NKp46 expression and NK1 shift in dNK cells. NKp46 expression could be a marker for RPL of immunological abnormalities.

Value of Autoantibody Expression During Long-Term Follow-Up in Paediatric ALL Patients After Allogeneic Haematopoietic Stem Cell Transplantation.

Objectives: Chronic graft-versus-host disease (cGvHD) following haematopoietic stem cell transplantation (HSCT) shares many similarities with de novo autoimmune disorders, being associated with the presence of autoantibodies. However, data on the implication of autoantibodies in paediatric HSCT recipients are scarce. In this single-centre study of paediatric patients with acute lymphoblastic leukaemia (ALL) surviving longer than 3 months, our objectives were to evaluate autoantibody expression and investigate the correlation with cGvHD and immune reconstitution using serially monitored parameters.Methods: We investigated circulating autoantibodies together with cellular and humoral parameters [including major T- and B-cell subsets, natural killer (NK) cells, and immunoglobulin levels] in 440 samples from 74 patients (median age 10.9 years, range 2.7–22.2 years) serially during long-term follow-up of median 8 years (range 0.4–19.3 years). Evaluations comprised of patient and transplant characteristics, precisely reviewed details of National Institute of Health (NIH)-defined cGvHD, and outcome data such as relapse, overall survival (OS) and mortality. Analysis of these clinical parameters was performed to identify possible associations.Results: Autoantibodies were detected in 65% (48/74) of patients. Anti-nuclear antibodies were the most common, occurring in 75% (36/48) of patients with autoantibodies. When comparing demographic data and transplant characteristics, there were no significant differences between patients with and without autoantibody expression; 5-year OS was excellent, at 96.4 and 95.8%, respectively. Neither the expression of autoantibodies nor the occurrence of cGvHD correlated with significantly worse OS or relapse rate. Furthermore, there was no significant association between autoantibody profiles and the incidence, overall severity or organ involvement of cGvHD. Patients with autoantibodies showed significantly better immune reconstitution, with overall higher numbers of T cells, B cells, and serum immunoglobulins. In autoantibody-positive patients with cGvHD, autoantibody production positively correlated with the expansion of CD56+ NK cells (236.1 vs. 165.6 × 103 cells/mL, respectively; p = 0.023) and with signs of B-cell perturbation, such as higher CD21low B cells (23.8 vs. 11.8 × 103 cells/mL, respectively; p = 0.044) and a higher ratio of CD21low B cells/CD27+ memory B cells (1.7 vs. 0.4, respectively; p = 0.006) in comparison to autoantibody-positive patients without cGvHD. Furthermore, when assessing the correlation between autoantibody positivity and the activity of cGvHD at time of analysis, indicators of aberrant B-cell homeostasis were substantiated by a lower proportion of CD27+ memory B cells (9.1 vs. 14.9%, respectively; p = 0.028), a higher ratio of class-switched CD27+IgD−/CD27+ memory B cells (3.5 vs. 5.1%, respectively; p = 0.013), significantly elevated numbers of CD21low B cells (36.8 vs. 11.8 × 103 cells/mL, respectively; p = 0.013) and a higher ratio of CD21lowB cells/CD27+ memory B cells (2.4 vs. 0.4, respectively; p = 0.034) in the active vs. the no cGvHD group. We then assessed the potential role of autoantibody expression in the context of elevated CD19+CD21low B cells (cutoff >7%), a well-known marker of cGvHD. Surprisingly we found a significant higher proportion of those cases where elevated CD21low B cells correlated with active cGvHD in samples from the autoantibody-negative group vs. the antibody-positive group (82 vs. 47%, respectively; p = 0.0053).When comparing immune parameters of the large proportion of survivors (89%) with the small proportion of non-survivors (11%), data revealed normalisation within the B-cell compartment of survivors: there were increased numbers of CD27+ memory B cells (54.9 vs. 30.6 × 103 cells/mL, respectively; p = 0.05), class-switched CD27+IgD− B cells (21.2 vs. 5.0 × 103 cells/mL, respectively; p < 0.0001), and immunoglobulin G4 (40.9 vs. 19.4 mg/dL, respectively; p < 0.0001). Overall mortality was significantly associated with an elevated proportion of CD21low B cells (13.4 vs. 8.8%, respectively; p = 0.039) and CD56+ NK cells (238.8 vs. 314.1 × 103 cells/mL, respectively; p = 0.019). In multivariate analysis, better OS was significantly associated with lower numbers of CD56+ NK cells [hazard ratio (HR) 0.98, p = 0.041] and higher numbers of CD27+ memory B cells [(HR) 1.62, p = 0.014].Conclusion: Our data shows that autoantibody profiles are not suitable biomarkers for diagnosing cGvHD in children or for predicting cGvHD severity, disease course and outcome. We identified a number of indicators of aberrant immune homeostasis associated with active cGvHD in paediatric ALL patients after HSCT. These findings confirm published results and suggest that candidate B cell subpopulations may serve as a surrogate measure for characterisation of cGvHD in paediatric HSCT for malignant diseases, and warrants confirmation in larger, multicentre studies.

Perfecting CAR Engraftment to a Tee (Cell) through Characterization of Single Cell Transcriptome Product and Understanding Neurotoxicity

Background: Autologous chimeric antigen receptor T (CAR-T) cell therapies show significant clinical activity against hematologic malignancies including multiple myeloma (MM). Numerous factors influence the effectiveness of this therapeutic approach. The fitness of a CAR-T cell product is an important factor affecting T cell engraftment and persistence, a pre-requisite for effective CAR-T cell therapy. In an effort to deconstruct the cellular heterogeneity of CAR-T cell products and explore relationships between T cell states within the cellular product, gene expression and CAR-T cell engraftment following adoptive transfer, we performed single cell RNA-sequencing (scRNA-seq) on CAR-T cell products from a phase I trial of BCMA-specific CAR-T cells in relapsed/refractory MM patients that included cohorts receiving a similar CAR-T cell dose with and without preconditioning with cyclophosphamide (NCT02546167, Cohen et al, J Clin Invest 2019).Method: scRNA-seq was performed on 25 unique products with an average of 8823 cells captured per product at an average depth of 40779 reads per cell. Batch effects were controlled by integration using established metrics for quality control. The linked inference of genomic experimental relationships (LIGER) method exhibited the most effective integration of 228,752 single cells across the 25 products. Annotation was completed by comparing transcriptomes of cells to the Blueprint/ENCODE references of pure immune cells. Differential gene expression (DGE) analysis was conducted by both Wilcoxon rank sum test testing and negative binomial distribution. Gene enrichment analysis was performed by comparing DGE with the Molecular Signatures Database v7.4. Cell to cell communication utilized the KEGG signaling pathway maps and curated lists of interactions from the literature. The intercellular communication probability was estimated on the DE genes before statistically significant intercellular communications were calculated by a permutation test, with dominant senders, receivers, mediators, and influencers identified using graph theory. Patients were grouped based upon “good” or “poor” engraftment using a peak blood vector copies per cell cutoff of 10,000. Association of transcriptional variation with neurotoxicity was explored for all patients.Results: The CD4:CD8 ratio of 2.51 single cells in the data was comparable to the observed average CD4:CD8 ratio of total T cells in the product based upon flow cytometric analysis of the products at harvest. Cell annotation showed significant heterogeneity of CD4+ and CD8+ T cells with cells exhibiting a CD4 Tcm transcriptional profile comprising the largest subset of T cells within the product. DGE analysis found 205 genes that were up or down regulated between the “good” vs “poor” engraftment phenotypes with 75 genes being detected using both mathematical approaches. CAR-BCMA expression was increased in “good” engraftment groups which has not previously been shown in CAR sorted cells. Within both CD4+ and CD8+ T cell subsets, transcriptional pathways associated with the RXF5/RFXAP/RFXANK transcriptional activator complex and the IL-2/STAT5 signaling were identified as upregulated in the “good” engrafted products. Cell to cell communication analysis for both secreted signaling and cell to cell contact revealed similar ligand-receptor interaction differences between the engraftment groups. Within the neurotoxicity groups CAR-BCMA expression was not associated with either neurotoxicity or with high and low neurotoxicity effects in the product. High vs low neurotoxicity showed a shift with interferon gamma and cytokine-cytokine interactions. We also detected IL-6/JAK/STAT3 signaling activation increases in this group.Conclusion: The RFX5/RFXAP/RFXANK pathway associated with MHC class II expression and IL-2/STAT5 signaling show a significant association with engraftment of BCMA-specific CAR-T cells. Although IL-2 signaling is well known to be critical to T cell survival and a potential key driver for long-term persistence, the role of the RFX5 transcriptional activator complex in T cells, outside of its important role in regulating MHC expression, is largely unknown. Both pathways deserve further investigation. Cell to cell communication between engraftment groups suggests CD4/CD8 interactions that might be beneficial to engraftment at the product manufacturing stage. [Display omitted] DisclosuresGarfall: Amgen: Honoraria; CRISPR Therapeutics: Research Funding; GlaxoSmithKline: Honoraria; Janssen: Honoraria, Research Funding; Novartis: Research Funding; Tmunity: Research Funding. Bu: Novartis: Current Employment, Patents & Royalties: Co-inventor on patent applications. Orlando: Novartis: Current Employment. Brogdon: Novartis Institutes for Biomedical Research: Current Employment. Pruteanu-Malinici: Novartis: Current Employment. Cohen: Janssen: Consultancy; Oncopeptides: Consultancy; Genentech/Roche: Consultancy; BMS/Celgene: Consultancy; AstraZeneca: Consultancy; Novartis: Research Funding; Takeda: Consultancy; GlaxoSmithKline: Consultancy, Research Funding.

Microparticles and PD1 interplay added a prognostic impact in treatment outcomes of patients with multiple myeloma

Although multiple myeloma (MM) is still considered as an incurable disease by current standards, the development of several combination therapies, and immunotherapy approaches has raised the hope towards transforming MM into an indolent, chronic disease, and possibly achieving a cure. We tried to shed light on the expression of PD1 and different Microparticles (MPs) in MM and their interplay as a mechanism of resistance to standardized treatments, in addition, find their associations with prognostic factors of symptomatic MM. Thirty patients with newly diagnosed and chemotherapy naïve active MM, along with 19 healthy participants of comparable age and sex were recruited, after diagnosis of MM; blood samples were collected from both patients and controls for flow cytometric detection of CD4+, CD8+, CD4+PD1+, and CD8+PD1+T cells, total MPs, CD138+ MPs, and platelet MPs. MM patients had statistically significant higher levels of TMPs, CD138+ MPs compared to their controls, while PMPs exhibited no significant difference between both groups. Statistically significant higher percentages of CD8+, PD1CD8+, PD1CD4+T cells were detected in patients compared to controls, while the latter group had a significantly higher percentage of CD4+T cells than MM patients, patients who did not achieve complete response, had significantly higher percentages of PMPs, CD138+MPs, PD1+CD8+, PD1+CD4+, and CD8+T cells (cutoff values = 61, 10.6, 13.5, 11.3 and 20.1 respectively), (p-values = 0.002, 0.003, 0.017, 0.001 and 0.008 respectively). Microparticles and PD1 expressions were associated with proliferative potential and resistance to Bortezomib-based treatments, our results suggested that they played a crucial role in myeloma progression.

Abstract LB034: Analysis of PD-L1 IHC tests using NIST SRM 1934-traceable reference materials: A new paradigm for development of predictive IHC biomarkers

Abstract BACKGROUND. The challenges in accurate patient stratification for immune checkpoint inhibitors have been compounded by the fact that the FDA-cleared PD-L1 IHC tests are analytic ‘black boxes'. Relatively basic analytic parameters such as lower limit of detection and analytic dynamic range are unknown to both developers of assays as well as end users. The recent development of standardized PD-L1 immunohistochemistry (IHC) reference materials enables quantitative test characterizations that were not previously possible. METHODS. We surveyed 41 PD-L1 testing laboratories in North America and Europe, quantitatively defining each of the PD-L1 tests' analytic performance in terms of lower limit of detection and dynamic range. All four commercial PD-L1 kits were assessed by multiple laboratories. A variety of laboratory-developed tests (LDTs) we also assessed. The reference materials incorporated defined concentrations of PD-L1 peptide (intracellular domain) or recombinant extracellular domain protein, traceable to NIST Standard Reference Material 1934. Each laboratory received a slide with 10 separate PD-L1 calibrator concentrations: 2,200 - 600,000 molecules of PD-L1 extracellular domain or 34,000 - 2,200,000 molecules of PD-L1 intracellular domain. The calibrator concentrations ranged from those that are below the lower limit of detection to others that yield maximal staining. RESULTS. The data obtained with the four PD-L1 kits (VENTANA PD-L1 (SP263) Assay, VENTANA PD-L1 (SP142) Assay, DAKO PD-L1 IHC 28-8 pharmDx and DAKO PD-L1 IHC 22C3 pharmDx assays) revealed that the lower limits of detection (PD-L1 molecules per cell equivalent) are approximately: 50,000 - 180,000 (SP263), 800,000 - 1,200,000 (SP142), 220,000 - 360,000 (28-8), and 200,000 - 400,000 (22C3). The dynamic ranges for all of these tests are generally narrow, spanning less than a log concentration of PD-L1. The SP263 and SP142 assays showed no overlap of their analytic response curves. This means that a maximal stain intensity with SP263 kit can be associated with zero staining with the SP142 kit. Consequently, it is not possible to compensate for the variability in analytic sensitivity between these two tests by adjusting the percent positive cell cutoff. The 28-8 was more sensitive than, but statistically indistinguishable from the 22C3 assay. Laboratory-developed tests (LDTs) using these and other primary antibodies have their own unique analytic performance characteristics. CONCLUSIONS. The PD-L1 reference materials enable precise definitions of analytic test performance and linking them with clinical management thresholds. Therefore, this tool finds its most important implementation at the stage of development of new IHC predictive biomarkers in clinical trials as well as at the stage of methodology transfer to clinical IHC laboratories. Furthermore, our results also help define more precisely the possibility for assay interchangeability and to what degree the assays may be harmonized. Citation Format: Emina E. Torlakovic, Seshi Sompuram, Kodela Vani, Steve Bogen. Analysis of PD-L1 IHC tests using NIST SRM 1934-traceable reference materials: A new paradigm for development of predictive IHC biomarkers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB034.

Optimal Synovial Fluid Leukocyte Count Cutoff for Diagnosing Native Joint Septic Arthritis After Antibiotics: A Receiver Operating Characteristic Analysis of Accuracy.

Urgent treatment of septic arthritis is key in preventing devastating morbidity or mortality. Accurate diagnosis is critical, and the standard diagnostic cutoff of 50,000 synovial leukocytes may be altered by previous administration of antibiotics. Our objective was to identify and compare a cutoff synovial leukocyte count with a high sensitivity and specificity for diagnosis of septic arthritis in patients who received antibiotics and those who had not. A receiver operating characteristic (ROC) curve was used to provide a discriminate cutoff value for diagnosing septic arthritis. A retrospective chart review of 383 patients was done over a 13-year period including those who had arthrocentesis of any joint. Two groups were created, those who had not been given antibiotics within 2 weeks (control) and those who received intravenous or oral antibiotics within 2 weeks before arthrocentesis. Relevant data included synovial leukocyte count and differential cell count. Additional metrics included temperature, erythrocyte sedimentation rate, and C-reactive protein. A ROC curve determined the optimal synovial white blood cell cutoff for diagnosing septic arthritis in native joints for each group. The ROC curve determined that patients who received antibiotics had an optimal cutoff of >16,000 cells (sensitivity = 82%, specificity = 76%), and a neutrophil percentage cutoff of >90% (sensitivity = 73%, specificity = 74%). The control group had an optimal synovial leukocyte cutoff of >33,000 cells (sensitivity = 96%, specificity = 95%). The optimal neutrophil percentage cutoff in the control group was >83% neutrophils (sensitivity = 89%, specificity = 79%). When a patient is given antibiotics before arthrocentesis, a diagnostic value of >16,000 synovial leukocytes should be used to guide treatment of septic arthritis. A diagnostic value of >33,000 synovial leukocytes yields the highest accuracy for diagnosis of septic arthritis in patients who have not been given antibiotics before arthrocentesis. III.

Pyuria and Urine Concentration for Identifying Urinary Tract Infection in Young Children.

Accuracy of pyuria for urinary tract infection (UTI) varies with urine concentration. Our objective of this study was to determine the optimal white blood cell (WBC) cutoff for UTI in young children at different urine concentrations as measured by urine specific gravity. Retrospective cross-sectional study of children <24 months of age evaluated in the emergency department for suspected UTI with paired urinalysis and urine culture during a 6-year period. The primary outcome was positive urine culture result as described in the American Academy of Pediatrics clinical practice guideline culture thresholds. Test characteristics for microscopic pyuria cut points and positive leukocyte esterase (LE) were calculated across 3 urine specific gravity groups: low <1.011, moderate 1.011 to 1.020, and high >1.020. Of the total 24 171 patients analyzed, urine culture result was positive in 2003 (8.3%). Urine was obtained by transurethral in-and-out catheterization in 97.9%. Optimal WBC cutoffs per high-power field (HPF) were 3 (positive likelihood ratio [LR+] 10.5; negative likelihood ratio [LR-] 0.12) at low, 6 (LR+ 12; LR- 0.14) at moderate, and 8 (LR+ 11.1; LR- 0.35) at high urine concentrations. Likelihood ratios for small positive LE from low to high urine concentrations (LR+ 25.2, LR- 0.12; LR+ 33.1, LR- 0.15; LR+ 37.6, LR- 0.41) remained excellent. Optimal pyuria cut point in predicting positive urine culture results changes with urine concentration in young children. Pyuria thresholds of 3 WBCs per HPF at low urine concentrations whereas 8 WBCs per HPF at high urine concentrations have optimal predictive value for UTI. Positive LE is a strong predictor of UTI regardless of urine concentration.

Programmed Death Ligand 1 Immunohistochemistry in Triple-Negative Breast Cancer: Evaluation of Inter-Pathologist Concordance and Inter-Assay Variability.

PurposeThe programmed death ligand 1 (PD-L1) SP142 assay with a 1% immune cell (IC) cutoff is approved for the selection of advanced triple-negative breast cancer (TNBC) patients for atezolizumab treatment. We aimed to evaluate the interobserver concordance of PD-L1 scoring and inter-assay variability of various PD-L1 assays in TNBC.MethodsThirty patients with primary TNBC were selected, and SP142, SP263, 22C3, and E1L3N assays were performed. PD-L1 staining in ICs and tumor cells (TCs) was scored by 10 pathologists who were blinded to the assay. The interobserver concordance among pathologists and the inter-assay variability of the four PD-L1 assays were analyzed. For SP142, the intraobserver concordance among the six pathologists was analyzed after training.ResultsThe adjusted means of PD-L1 IC scoring ranged from 6.2% to 12.9% for the four assays; the intraclass correlations showed moderate (0.584–0.649) reader concordance. The PD-L1 IC scoring with a 1% cutoff resulted in identical scoring in 40.0%–66.7% of cases and a poor to moderate agreement (Fleiss κ statistic [FKS] = 0.345–0.534) for the four assays. The SP142 assay had the widest range of positive rate (56.5%–100.0%), lowest number of cases with identical scoring, and lowest FKS at 1% cutoff. Pairwise comparison of adjusted means showed significantly decreased PD-L1 staining in SP142 compared with the other assays in both ICs and TCs. As for the intraobserver concordance in the SP142 assay, the overall percent agreement was 87.8% with a 1% IC cutoff. After training, the proportion of cases with identical scoring at a 1% IC cutoff increased to 70.0%; the FKS also increased to 0.610.ConclusionThe concordance of PD-L1 IC scoring among pathologists was low, at the 1% cutoff for the SP142 assay without training. SP142 showed the lowest PD-L1 expression in both IC and TC.

Operando Electrochemical Dilatometry of Si-Based Electrodes for Lithium-Ion Cells

Silicon is a promising next-generation anode material for Li-ion batteries, given its high specific capacity, abundance and low working potential. However, its application in commercial cells has been hindered by the large volumetric changes that occur during the Li (de)alloying process. While theoretical calculations predict that the full lithiation of a silicon particle would lead to ~300% expansion,1 experiments suggest that the material can undergo even larger dimensional variations due to morphological changes during repeated cycling.2 Most of the degradation mechanisms associated with Si-based electrodes, which are responsible for the poor cycling stability and rapid capacity decay, derive from the cyclic swelling/contraction effect. Understanding how the particle-level expansion projects into the electrode scale is hence a very relevant topic, specifically considering that composite electrodes are a complex combination of pores and both active and inactive materials.In this study, we use operando electrochemical dilatometry to quantify the thickness variation of Si-based electrodes during cycling. An example plot from a 70 wt% Si electrode is shown in Figure 1. The electrode expands to 300% of its initial thickness upon full lithiation. However, the swelling shows a nonlinear behavior being much slower during the initial 1000 mAh/g. At this point, the thickness change is only 17% although ~40% of the electrode capacity is utilized. During this regime, porosity and particle rearrangement within the anode may be able to partially accommodate the particles expansion. Past this stage, however, there is a steep increase in electrode dilation, which often results in coating delamination, as confirmed by post-mortem inspections.Such quantitative analyses provide important insights into the relationship between electrode capacity and expansion. More importantly, these results can be applied to inform cell design, provide guidelines for selection of cell cutoff voltages, and estimate the effect of anode utilization on cell performance. Obtaining reliable dilatometry information is challenging: hence, strategies for designing experiments that yield reproducible results will also be discussed during the presentation. REFERENCES 1. Kim et al., Journal of Physical Chemistry C, 115, 2514 (2011). 2. Wetjen et al., Journal of The Electrochemical Society, 165, A1503 (2018).Acknowledgement: We are grateful for support from B. Cunningham at the U.S. DOE Office of Vehicle Technology. This document has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357. Figure 1

Improved Multiple-Mixing-Cell Method for Accelerating Minimum Miscibility Pressure Calculations

Summary An improved algorithm for accelerating minimum miscibility pressure (MMP) computation using the multiple-mixing-cell (MMC) methods is presented. The MMC method is widely used to accurately calculate the MMP. In this study, we proposed an acceleration algorithm toward original MMC method to directly locate the shortest key tie-line (TL) after a certain amount of contacts through the adjustment of the gas/oil mixing ratio during the calculation process. The algorithm contains the following key components: (1) mixing cell cutoff strategy to avoid unnecessary flash calculations; (2) gas/oil mixing ratio adjustment to prevent lost information on the shortest key TL during the cell cutoff process; (3) a search algorithm for pressure to improve the next step pressure estimate; (4) the fast and reliable two-phase flash implementation by combining full Newton method with recently proposed iteration variables and conventional successive substitution method. The improved MMC model is shown to be faster than the original MMC method in computing MMP.

Prognostic Significance of CD45dimCD117+ Cells in Patients with Acute Myeloid Leukemia after Complete Remission

To investigate the predictive value of CD45dimCD117+ phenotype-abnormal cells (hereinafter referred to as "abnormal cells") for relapse and prognosis in adult patients with acute myeloid leukemia (AML) within 2 weeks after the first complete remission (CR1). The clinical data of patients with newly diagnosed AML (non-acute promyelocytic leukemia) admitted in our department from July 1, 2014 to June 30, 2017 were analyzed retrospectively, and the relationship between clinical features at the initial diagnosis and the abnormal phenotype cells of CD45dimCD117+ within 2 weeks after CR1 with the prognosis were analyzed. A total of 91 patients with CD45dimCD117+ abnormal cells were detected. The median age was 51 years old, the median WBC count was 11.60×109/L, and the median ratio of bone marrow blast cells was 0.35 at initial diagnosis. According to the FAB classification, 1 (1.1%), 7 (7.7%), 38 (41.7%), 20 (22.0%), 21 (23.1%) and 4 (4.4%) patients were classifice as M0, M1, M2, M4, M5, and M6, respectively. According to the NCCN risk stratification, 30 (33.0%), 51 (56.0%), and 10 (11.0%) patients were determined as good, moderate, and poor prognosis, respectively. The median ratio of abnormal cells within 2 weeks after CR1 was 1.8500 (0.0236-8.0000)%. The median time from initiation of induction therapy to the acquisition of CR was 46 days, median recurrence-free survival time was 319 days, and median overall survival time was 352 days. A total of 45 patients relapsed, of which 14 died; 46 patients did not relapse, of which 3 died. The cutoff of abnormal cells by receiver operating characteristic curve (ROC) analysis was 2.055% (Se=0.733，Sp=0.761). The abnormal cell ratio was＞2.055% in 44 patients, the median ratio of abnormal cells was 3.075%, among which 33 patients relapsed and 12 patients died; the abnormal cell ratio was ＜2.055% in 47 patients, the median ratio of abnormal cells was 1.150%, 12 patients relapsed and 5 patients died. Regression analysis showed that WBC count＞50×109/L and abnormal cell ratio＞2.055% were independent risk factors for recurrence. The abnormal cell ratio＞2.055% group had a 2-year RFS rate of 54.3% and a 2-year OS rate of 52.8%. The abnormal cell ratio＜2.055% group had a 2-year RFS rate of 86.6% (P=0.018), and a 2-year OS rate of 85.3% (P＜0.05). For adult AML patients, CD45dimCD117+ phenotypical abnormal cells ratio＞2.055% within 2 weeks after CR1 is an independent risk factor for recurrence, which also is an dverse factor for RFS and OS.

An Approach for Pre-Lithiation of Li1+xNi0.5Mn1.5O4 Cathodes Mitigating Active Lithium Loss

A major challenge for longer life lithium ion batteries is the irreversible loss of active lithium during the first charge/discharge cycles, which consequently reduces the practical energy density in cells without lithium ion excess. This degradation mechanism is especially detrimental for high-capacity anodes with low first cycle Coulombic efficiency. The present study aims for overcoming this challenge by pre-lithiating the high-voltage spinel LiNi0.5Mn1.5O4 (LNMO) positive electrode material with a simple and easily scalable chemical process via stirring LNMO particles with Li metal in boiling pentanol. The subsequent structural and electrochemical analysis proves the electrochemical accessibility of the “extra” lithium and long-term cycling stability. Charging/discharging the material in LNMO || graphite (C) and LNMO || silicon/carbon (Si/C) cells demonstrates positive effects on discharge capacity, energy and capacity retention. Furthermore, the additional active lithium is used to increase the specific capacity of the cells by including the lower potential region of LNMO through application of a lower cell cutoff voltage of 2.4 V. Comparing “standard” LNMO || C with pre-lithiated LNMO || Si/C cells (both charged/discharged at standard cutoff voltages of 3.0 and 4.95 V), improvements in specific energy of >21% can be identified.

Avelumab in patients with previously treated metastatic adrenocortical carcinoma: phase 1b results from the JAVELIN solid tumor trial

BackgroundWe assessed the efficacy and safety of avelumab, an anti-programmed death ligand 1 (PD-L1) antibody, in patients with previously treated metastatic adrenocortical carcinoma (mACC).MethodsIn this phase 1b expansion cohort, patients with mACC and prior platinum-based therapy received avelumab at 10 mg/kg intravenously every 2 weeks. Continuation of mitotane was permitted; however, mitotane levels during the study were not recorded. Tumor response was assessed by Response Evaluation Criteria In Solid Tumors v1.1.ResultsFifty patients received avelumab and were followed for a median of 16.5 months. Prior treatment included ≥2 lines in 74.0%; mitotane was continued in 50.0%. The objective response rate (ORR) was 6.0% (95% CI, 1.3% to 16.5%; partial response in 3 patients). Twenty-one patients (42.0%) had stable disease as best response (disease control rate, 48.0%). Median progression-free survival was 2.6 months (95% CI, 1.4 to 4.0), median overall survival (OS) was 10.6 months (95% CI, 7.4 to 15.0), and the 1-year OS rate was 43.4% (95% CI, 27.9% to 57.9%). In evaluable patients with PD-L1+ (n = 12) or PD-L1− (n = 30) tumors (≥5% tumor cell cutoff), ORR was 16.7% vs 3.3% (P = .192). Treatment-related adverse events (TRAEs) occurred in 82.0%; the most common were nausea (20.0%), fatigue (18.0%), hypothyroidism (14.0%), and pyrexia (14.0%). Grade 3 TRAEs occurred in 16.0%; no grade 4 to 5 TRAEs occurred. Twelve patients (24.0%) had an immune-related TRAE of any grade, which were grade 3 in 2 patients (4.0%): adrenal insufficiency (n = 1), and pneumonitis (n = 1).ConclusionsAvelumab showed clinical activity and a manageable safety profile in patients with platinum-treated mACC.Trial registrationClinicaltrials.gov NCT01772004; registered January 21, 2013.

Abstract CT111: Avelumab (anti-PD-L1) as first-line maintenance (1L mn) or second-line (2L) therapy in patients with advanced gastric or gastroesophageal junction cancer (GC/GEJC): updated phase Ib results from the JAVELIN Solid Tumor trial

Abstract Background: Patients (pts) with advanced GC/GEJC have a poor prognosis and standard chemotherapy options provide limited efficacy with significant toxicity. Avelumab, a human anti–PD-L1 IgG1 monoclonal antibody, has shown durable efficacy and acceptable safety in various tumor types. Here, we report updated data from JAVELIN Solid Tumor (NCT01772004) for avelumab treatment in pts with previously treated GC/GEJC. Methods: Pts with advanced GC/GEJC without or with disease progression after first-line combination chemotherapy in the metastatic setting (1L mn and 2L subgroups, respectively) received avelumab 10 mg/kg IV Q2W until confirmed progression, unacceptable toxicity, or withdrawal. Best overall response and progression-free survival (PFS) per RECIST v1.1 and overall survival (OS) were evaluated from the start of avelumab treatment. Time-to-event endpoints were estimated using the Kaplan–Meier method. Results: As of Sep 30, 2017, pts in the 1L mn subgroup (n=90) and 2L subgroup (n=60) had a median (range) follow-up of 36.0 mo (27–42) and 33.7 mo (25–42), respectively. In the 1L mn subgroup, best response on prior chemotherapy was partial response in 27.8%, stable disease in 65.6%, and not evaluable in 6.7%. Confirmed objective response rate (ORR) during avelumab 1L mn therapy (additional effect after end of chemotherapy) was 6.7% (95% CI 2.5–13.9), including complete response in 2.2%. Median duration of response was 21.4 months (95% CI 4.0–not estimable) and responses to avelumab lasted ≥12 mo in an estimated 50.0% of responders (95% CI 11.1–80.4). In evaluable pts with PD-L1+ (n=26) and PD-L1− (n=51) tumors (≥1% tumor cell cutoff; Dako PD-L1 IHC 73-10 pharmDx assay), ORR was 7.7% (95% CI 0.9–25.1) vs 3.9% (95% CI 0.5–13.5). The disease control rate (DCR) was 56.7% and median PFS was 2.8 mo (95% CI 2.3–4.1); median OS was 11.1 mo (95% CI 8.9–13.7) when measured from the start of avelumab therapy (12-mo rate 46.2%; 95% CI 35.6–56.1), and 18.7 mo (95% CI 15.4–20.6) when measured from start of 1L chemotherapy. In the 2L subgroup, confirmed ORR was 6.7% (95% CI 1.8–16.2), DCR was 28.3%, median PFS was 1.4 mo (95% CI 1.3–1.5), and median OS was 6.8 mo (95% CI 5.4–9.5). Across both subgroups, 56.7% had a treatment-related adverse event (TRAE) of any grade, most commonly (&amp;gt;10%) infusion-related reaction (12.7%) and fatigue (10.0%). 8.7% had a grade ≥3 TRAE, with 1 treatment-related death (hepatic failure/autoimmune hepatitis). 15.3% had an immune-related AE (grade ≥3 in 2.0%). Conclusion: Avelumab showed promising clinical activity and an acceptable safety profile in pts with advanced GC/GEJC with prior chemotherapy. A phase 3 trial of avelumab as 1L mn therapy vs continuation of 1L chemotherapy in pts with advanced GC/GEJC is ongoing (NCT02625610). Citation Format: Hyun Cheol Chung, Hendrik-Tobias Arkenau, Jeeyun Lee, Sun Young Rha, Do-Youn Oh, Lucjan Wyrwicz, Yoon-Koo Kang, Keun-Wook Lee, Todd M. Bauer, Sung Sook Lee, Margaret Kemeny, Ulrich Keilholz, Bohuslav Melichar, Alain Mita, Ruth Plummer, Denis Smith, Arnold B. Gelb, Huiling Xiong, Janet Hong, Vikram Chand, Howard Safran. Avelumab (anti-PD-L1) as first-line maintenance (1L mn) or second-line (2L) therapy in patients with advanced gastric or gastroesophageal junction cancer (GC/GEJC): updated phase Ib results from the JAVELIN Solid Tumor trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT111.

Abstract 4517: Characterization of a standardized immunohistochemical assay for detecting PD-L1 expression in non-small cell lung cancer using anti-PD-L1 clone 73-10

Abstract Background: Recent data have demonstrated the clinical efficacy of anti-PD-1/PD-L1 checkpoint inhibitors in non-small cell lung cancer (NSCLC), and approvals by regulatory authorities in first-line and second-line settings have followed. In selected treatment scenarios, expression of PD-L1 by immunohistochemistry (IHC) is considered predictive of patient outcome. A recent comparative study using the rabbit anti-PD-L1 monoclonal antibody clone 73-10 and other commercialized IHC assays demonstrated strong intra-assay reliability in NSCLC tumor cell scoring and inter-assay differences in the number of tumor cells detected by each assay (Blueprint 2 data presented at IASLC 2017). Here we report precision around a ≥ 1% tumor cell cutoff and PD-L1 expression in 428 procured NSCLC tissues using an immunohistochemical assay developed with this antibody clone. Methods: PD-L1 expression was assessed using a standardized PD-L1 IHC assay. Scoring of tumor specimens was performed on a 0 - 3+ intensity scale, with membrane staining in ≥ 1% of tumor cells at ≥ 1+ intensity defining PD-L1 positivity. Assay precision around this cutoff was assessed in 28 specimens. PD-L1 expression was evaluated in 428 Stage IIIA, IIIB, and IV procured NSCLC tissues. Assay specificity was examined in 30 normal tissues. Results: The PD-L1 IHC 73-10 assay showed &amp;gt; 95% negative, positive, and overall agreement in inter-day, inter-operator, intra-run, inter-instrument, and inter-lot conditions around the ≥ 1% tumor cell cutoff. The lower bound of the 95% confidence interval was &amp;gt; 90% for all agreement types and precision conditions. PD-L1 protein localization in normal tissues was consistent with known patterns. The 428 procured NSCLC samples had primarily squamous cell (39.5%), adenocarcinoma (43.7%) and a mixture of other less common (16.8%) histologic subtypes; 397 (92.8%) of samples were from primary and 31 (7.2%) were from metastatic tumors. Crisp membrane staining was observed in tumor cells. Other labeled cell types included macrophages, lymphocytes, endothelial cells, and fibroblasts that exhibited membrane and/or cytoplasmic staining. Of the 428 procured specimens, 270 (63.0%) were PD-L1-positive based on the ≥ 1% cutoff. Tissues of each NSCLC stage expressed PD-L1 in the full dynamic range from 0% - 100% positive. Conclusions: These data provide insight into the prevalence of PD-L1 expression in procured NSCLC specimens when stained with PD-L1 IHC 73-10, and demonstrate that this assay is precise around a ≥ 1% tumor cell cutoff while exhibiting expected antigen specificity. PD-L1 positivity in the tumor stages examined using this assay is greater than in the literature, where prevalence using different antibodies has been reported at less than 50% in various stages. Citation Format: Darlene Krohn, Mai Nguyen, Marko Srdanov, Christina Samathanam, Peng Duan, Monika Vilardo, Alexander Prenta, Sharika Vasudevan, Landry Nicholson-Legg, Debra Hanks, Aaron R. Ellison. Characterization of a standardized immunohistochemical assay for detecting PD-L1 expression in non-small cell lung cancer using anti-PD-L1 clone 73-10 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4517.

Avelumab in patients with previously treated mesothelioma: Updated phase 1b results from the JAVELIN Solid Tumor trial.

166 Background: Avelumab, a human anti-PD-L1 IgG1 monoclonal antibody, is approved for treatment of metastatic Merkel cell carcinoma (US and EU) and advanced urothelial carcinoma progressed on platinum therapy (US). Here, we report updated phase 1b data for avelumab in patients (pts) with previously treated mesothelioma. Methods: Pts with unresectable pleural or peritoneal mesothelioma whose disease had progressed after platinum and pemetrexed therapy received avelumab 10 mg/kg IV Q2W until progression, unacceptable toxicity, or withdrawal. Tumors were assessed every 6 wks (RECIST 1.1). Endpoints included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs; NCI CTCAE v4.0). Results: As of Dec 31, 2016, 53 pts were treated and followed for a median of 24.8 mos (range 16.8–27.8). Median age was 67 y (range 32–84). Pts had received a median of 2 prior lines of therapy (range 1–8). Confirmed ORR was 9.4% (95% CI 3.1–20.7; complete response in 1.9%, partial response in 7.5%). In pts with 1 (n = 18), 2 (n = 15) or ≥3 (n = 20) prior lines of therapy, ORR was 5.6%, 13.3% and 10.0% respectively. Median duration of response was 15.2 mos (95% CI 11.1–not estimable). 26 pts (49.1%) had stable disease as best response and the disease control rate was 58.5%. Median PFS was 4.1 mos (95% CI 1.4–6.2) and the 6-mo PFS rate was 38.0% (95% CI 24.2–51.7). Median OS was 10.9 mos (95% CI 7.5–21.0) and the 12-mo OS rate was 45.9% (95% CI 31.9–58.8). In evaluable pts with PD-L1+ (n = 16) and PD-L1− (n = 27) tumors (≥5% tumor cell cutoff), ORR was 18.8% (95% CI 4.0–45.6) and 7.4% (95% CI 0.9–24.3), and the 6-mo PFS rate was 37.5% (95% CI 14.1–61.2) and 42.0% (95% CI 23.1–59.8). 43 pts (81.1%) had a treatment-related (TR)AE, most commonly ( &gt; 10%) infusion-related reaction (35.8%; all grade 1/2), chills (15.1%), fatigue (15.1%) and pyrexia (11.3%). 5 pts (9.4%) had a grade ≥3 TRAE. 14 pts (26.4%) had an immune-related AE, which was grade ≥3 in 3 pts (5.7%; pneumonitis, colitis, and type 1 diabetes mellitus). No treatment-related deaths occurred. Conclusions: Avelumab showed clinical activity and acceptable safety in pts with previously treated mesothelioma. Clinical trial information: NCT01772004.

Systematic Review and Meta-Analysis of Individual Patient Data to Assess the Sensitivity of Cervical Cytology for Diagnosis of Cervical Cancer in Low- and Middle-Income Countries.

PurposeTo assess the sensitivity of cervical cytology to cancer by pooling individual patient cytology results from cancers diagnosed in studies that assessed cervical screening in low- and middle-income countries.MethodsTwo authors reviewed studies identified through PubMed and Embase databases. We included studies that reported cervical cytology in which at least one woman was diagnosed with cervical cancer and in which abnormal cytology results were investigated at colposcopy and through a histologic sample (if appropriate). When cytology results were not reported in the manuscript, authors were contacted. Stratified analyses and meta-regression were performed to assess sources of heterogeneity between studies.ResultsWe included 717 cancers from 23 studies. The pooled sensitivity of cytology to cancer at a cutoff of a high-grade squamous intraepithelial lesion (HSIL) or worse was 79.4% (95% CI, 67.7% to 86.0%). Results from stratified analyses did not differ significantly, except among studies that recruited symptomatic women or women referred because of abnormal cytology, when the sensitivity of cytology was much higher (95.9%; 95% CI, 86.5% to 99.9%). The cutoff of an HSIL or worse detected 85% of the cancers that would have been detected at a cutoff of atypical squamous cells of undetermined significance or worse (relative sensitivity, 85.2%; 95% CI, 80.7% to 89.7%).ConclusionCytology at a high cutoff could be an excellent tool for targeted screening of populations at high risk of cervical cancer with a view to diagnose cancer at an earlier stage.