The NCCN Guidelines for Cancer-Associated Venous Thromboembolic Disease provide strategies for the prevention, diagnosis, and treatment of venous thromboembolism (VTE) in adult patients with cancer. VTE is a common and life-threatening condition in patients with cancer, and its management often requires multidisciplinary efforts. The NCCN panel is comprised of specialists spanning various fields, including cardiology, hematology, medical oncology, internal medicine, interventional radiology, and pharmacology. The content featured in this issue specifically addresses the evaluation and recommended treatment options outlined in the NCCN Guidelines for the diverse subtypes of cancer-associated VTE.

Distinguishing DIC from the coagulaopathy of liver disease represents a common clinical challenge. Here, we evaluated the clinical utility of two diagnostic tools frequently used to differentiate between these conditions: factor VIII (FVIII) levels and the ISTH DIC score.

INTRODUCTION:Distinguishing disseminated intravascular coagulation (DIC) from the coagulopathy of liver disease represents a common clinical challenge. Here, we evaluated the utility of two diagnostic tools frequently used to differentiate between these conditions: factor VIII (FVIII) levels and the International Society on Thrombosis and Hemostasis (ISTH) DIC score. METHODS:To this end, we conducted a retrospective chart review of patients with DIC, liver disease, or both. Multiple logistic regression was performed, and receiver operating characteristic curves were generated to calculate the area under curve (AUC) for distinguishing DIC in the setting of liver disease. RESULTS:Among 123 patients with DIC, liver disease, or liver disease plus DIC, FVIII levels did not differ significantly. ISTH scores were lower in patients with DIC than in liver disease with or without DIC. Addition of several laboratory parameters to the ISTH score, including mean platelet volume, FV, FVIII, international normalized ratio, and activated partial thromboplastin time, improved AUC for distinguishing DIC in liver disease from liver disease alone (AUC = 0.76; p < 0.0001). CONCLUSION:We conclude that FVIII levels do not distinguish DIC from liver disease, and ISTH DIC scores are not predictive of DIC in patients with liver disease. Inclusion of additional lab variables within the ISTH DIC score may aid in identifying DIC in patients with liver disease.

The NCCN Guidelines for Cancer-Associated Venous Thromboembolic Disease provide strategies for the prevention, diagnosis, and treatment of venous thromboembolism (VTE) in adult patients with cancer. VTE is a common and life-threatening condition in patients with cancer, and its management often requires multidisciplinary efforts. The NCCN panel is comprised of specialists spanning various fields, including cardiology, hematology, medical oncology, internal medicine, interventional radiology, and pharmacology. The content featured in this issue specifically addresses the evaluation and recommended treatment options outlined in the NCCN Guidelines for the diverse subtypes of cancer-associated VTE.

Introduction. In response to a growing and increasingly older population with complex medical needs, the hematology and oncology (HO) care system has integrated the hospitalist model into inpatient systems alongside HO trainees and faculty. The inclusive workforce is comprised of hospitalists and advanced practice providers (APPs) who co-manage patients with specialists or form separate non-trainee (NT) teams. Despite multiple advantages of the hospitalist model, the optimal care team structure and the impact on HO fellowship training have not been previously explored. We aimed to survey HO fellowship programs in the United States to identify the structure of inpatient HO staffing models implemented at their institution, and collect data on perceptions of the NT model within the fellowship programs. Methods. We constructed and distributed two national web-based surveys targeting all adult HO fellowship program directors (PDs) and fellows from Accreditation Council for Graduate Medical Education (ACGME)-accredited programs. The surveys were designed to assess various aspects of HO inpatient services, including team compositions, individual responsibilities, and availability of NT services. We also assessed the PDs' and fellows' perception on the impact of NT teams on their training and education. The surveys were emailed weekly between 6/20/23-7/29/23. Results.We identified 147 HO training programs.A total of 35 PDs and 101 fellows responded our survey (Table 1). The majority of PDs (83%) were from university training programs in the Midwest (43%) and Northeast (33%), with fellow class sizes of 6-12 (47%). Most (67%) programs had both trainee (T) and NT teams included in their inpatient medicine models (Figure 1). The most commonly reported NT team was the bone marrow transplant and cellular therapy service (BMT) (57%), supported primarily by APPs (55%). Only 33% of respondents reported a dedicated sickle cell disease (SCD) inpatient team within their institution. Hospitalists were included in the care model of the inpatient oncology (27%), inpatient malignant hematology (23%) and SCD (13%) teams. Most PDs agreed that the fellows are primarily responsible for most inpatient tasks and over 50% agreed that APPs are responsible for direct patient care, admissions and discharge planning. 83% of PDs reported that their program had an appropriate balance between inpatient and outpatient care. Half (50%) of PDs reported that fellows had a positive perception of NT teams at their institution, and 35% were neutral. The fellows who responded were predominantly second-year fellows (43%) in Northeastern (43%) university hospitals (92%) from programs with 6-12 fellows (63%). Most (71%) respondents had both T and NT teams included in their inpatient model. Inpatient malignant hematology (53%) and inpatient solid oncology (53%) teams were the most commonly reported NT teams, followed by BMT (40%) (Figure 1). Fellows reported their primary responsibilities to include procedures and tumor board discussions (94%), communication with outpatient teams (91%) and resident education and supervision (89%). APPs were primarily responsible for discharge planning (63%), admissions (59%) and direct patient care (58%). Most (85%) fellows agreed that their program had an appropriate balance between inpatient and outpatient care. Most fellows (69%) reported the impact of NT teams on fellows' inpatient and training experience to be neutral. Fellows from institutions without NT teams responded that the addition on NT team would have a positive impact in their training experience (69%). Most PDs and fellow respondents perceived a financial barrier to the implementation of NT teams at their institutions. Conclusions.Our findings highlight the existing heterogeneity in the distribution and composition of services among HO programs nationwide. PD respondents and fellows without NT teams perceived these teams as a beneficial addition to the program, in contrast to fellows in programs with existing NT teams who reported a neutral impact. Further investigation of the reasons for this discrepancy is essential to identify areas of improvement. Additional insights from the ongoing survey will be presented during the meeting.

TK and SM are Co-first authors INTRODUCTION Treatment with chimeric antigen receptor (CAR) T-cells significantly improved outcomes in relapsed/refractory non-Hodgkin lymphoma (NHL) and multiple myeloma (MM). CAR-T activation and anti-tumor cytotoxicity are associated with bystander inflammatory reactions resulting in CRS and/or ICANS. Due to complex cytokine profiles, disease heterogeneity, and variability between commercial CAR-T products, identification of risk factors associated with CRS and/or ICANS has been challenging. In this study, we used plasma proteomic profiling at different timepoints to identify possible inflammatory mediators associated with CRS and ICANS METHODS We prospectively collected plasma samples from patients who received CAR-T cells therapy between 9/2021 to 12/2022 at several time points - before lymphodepletion chemotherapy on day -5 (relative to CAR-T cell infusion), prior to CAR T-cell infusion on day 0, and post CAR T-cell therapy on days 1, 2, 3, and 7. Protein profiling analyses were conducted at Eve Technologies (Calgary, Alberta, Canada) using an assay measuring 71 total cytokines and chemokines. Proteins levels were compared across different time points used Wilcoxon rank test, while features associated with CRS/ICANS were identified using logistic regression. Receiver operating characteristic (ROC) analysis used to identify variables predictive for CRS. Area under the curve (AUC) of at least 0.8 was used and best cutoffs were determined according to Youden index. P-values <0.05 were considered statistically significant. This study was supported in part by The Frederick A. Deluca Foundation. RESULTS Overall, 56 patients with available cytokine assays at all time points were included. The median age was 65 years (IQR: 57-74) and 70% were men. Of all patients, 26 (46%) had diffuse large B-cell lymphoma (DLBCL), 23 (41%) MM, 4 (7%) mantle cell lymphoma, and 3 (6) follicular lymphoma. Ide-cel (39%), liso-cel (36%), and axi-cel (17%) were the most used CAR-T cell products. All patients received lymphodepleting chemotherapy with fludarabine/cyclophosphamide. In total, 35 (63%) patients developed CRS (grade 1, 89%; grade 2, 8%; grade 3, 3%) and 18 (32%) patients developed ICANS (grade 1, 72%; grade 2, 22%; grade 3, 6%). Compared to patients who did not develop CRS, patients with CRS had lower median absolute lymphocyte counts at day -5 (0.02 x10 9/L vs. 0.05, p=0.0146), higher baseline CRP (13 vs. 4 mg/L, p=0.0005), and higher ferritin (914 vs. 442 mg/L, p=0.048). No differences in the type of CAR-T products (p=0.090), percentages of DLBCL or MM (p=0.270) were observed between CRS and no CRS cohorts ( Panel-A). First, we investigated the proteomic profiles at baseline for CRS odds. Hemoglobin (odd ratio [OR]: 0.6, 95%CI: 0.4-0.8) was associated with lower odds for CRS while IL6 (2.0, 1.2-3.3) and stem cell factor (scf 2.2, 1.2-4.2) were associated with higher odds of CRS. We then analyzed the differences in cytokine levels between day 0 and day 3 to select cytokines with significant changes for further analysis ( Panel-B). At day 3, groa (1.9, 1.1-3.3), IL3 (1.6, 1.2-2.1), IL5 (1.5, 1.2-1.9), IL6 (1.7, 1.3-2.3), IL10 (2.0, 1.3-3.0), TNFα (2.0, 1.1-3.6), and mcp2 (2.5, 1.2-5.3) were all associated with higher odds for CRS. Based on ROC analysis at day 3, best cutoff points to estimate CRS (value, sensitivity/specificity) for IL3 (3, 80%/90%), IL5 (197, 74%/85%), IL6 (11, 70%/85%), and IL10 (53, 74%/85%) were identified. Based on that, elevated IL3 (OR:24, 95%CI: 6-105), IL5 (11, 3-40), IL6 (21, 5-95), and IL10 (12, 3-46) were associated with higher odds for CRS. For ICANS, day 3 IL3 (1.5, 1.2-1.9), IL6 (1.2, 1.1-1.5), IL8 (2.1, 1.4-3.3), and IL10 (1.7, 1.3-2.4) were associated with higher odds for ICANS. Best cutoff points to estimate ICANS at day 3 (value, sensitivity/specificity) for IL3 (5, 78%/76%), IL6 (115, 78%/78%), IL10 (130, 81%/80%), and IL8 (21, 83%/81%) were identified. Based on that, elevated IL3 (OR:10, 95%CI: 3-37), IL6 (11, 3-43), IL10 (13, 3-51), and IL8 (19, 4-81) were associated with higher odds for ICANS. CONCLUSIONS In our comprehensive plasma proteomic profiles analysis, we identified cutoffs for IL3, IL6, IL5 and IL10 that may be predictive for CRS and ICANS regardless of CAR-T cell product. Our results are clinically applicable and may be used to recognize patients at risk for CRS and/or ICANS who may be eligible for prophylactic therapies.

Background. Antiphospholipid syndrome (APS) is an autoimmune disease with thrombotic and obstetric complications arising via a model of immunothrombosis. Patients may present with a spectrum of phenotypes, including thrombotic (tAPS), obstetric (oAPS), or catastrophic/microvascular APS (C/MAPS), while others may have antiphospholipid antibodies (aPL) without disease manifestations. The mechanisms underlying the development of these diverse phenotypes remain uncertain. Proteomic profiling was used in other thrombotic and microvascular disorders to highlight potential mechanisms of disease pathogenesis and may have a role in understanding the pathophysiology of APS. We performed multiplex plasma proteomic profiling in aPL-positive patients with different clinical phenotypes to gain a greater understanding of potential immunothrombotic mechanisms in the pathogenesis of APS. Methods. We utilized samples from APS ACTION Registry. The inclusion criteria were positive aPL per Updated Sapporo Classification Criteria tested within one year prior to the enrollment. Multiplex proteomic profiling measuring approximately 7,000 unique proteins (SomaLogic; Boulder, CO, USA) was performed on 40 primary aPL-positive patient plasma samples (10 each of tAPS with/without oAPS, oAPS only, C/MAPS, and positive aPL without APS classification), and 10 of healthy controls. Differentially abundant proteins among all phenotypic groups and in pairwise comparisons were determined by applying ANOVA and t-tests to log-normalized data, respectively, with p-values <0.05 considered statistically significant (Qlucore Omics Explorer, Lund, Sweden). Tests were adjusted for false discovery (q<0.1) to minimize the likelihood of false positives. Pathway enrichment analysis was performed using Metascape (https://metascape.org) and Ingenuity IPA (Qiagen, Venlo, Netherlands) platforms. Results. The median age of patients was 48 years; 30% were men, 70% had triple aPL-positivity, and no one had a concurrent diagnosis of lupus. A set of concordant and differentially abundant proteins clustered patients with 4 APS clinical phenotypes and controls (Figure A) with a high statistical significance (p<0.0007) and a high false discovery confidence (q<0.05). Proteins in the identified set belonged to several highly enriched pathways such as neutrophil degranulation (p<10 -10), humoral immune response (p<10 -9), coagulation (p<10 -6), and alternative complement (p<10 -5) [data not shown]. Pathway enrichment analysis of protein sets identified in pairwise comparisons of APS phenotypes (aPL vs C/MAPS, aPL vs tAPS, tAPS vs C/MAPS) revealed involvement of several common pathways associated with inflammation, collagen and fibroblast signaling, cellular and cytoskeletal activation, humoral immune response, myeloid and effector cell differentiation and recruitment, and immunothrombosis such as Pathogen-Induced Cytokine Storm, Neutrophil Extracellular Trap (NET), and collagen-induced platelet-activating GP6 signaling (Figure B). For several pathways, the measure of activation related to increased or predicted to be increased proteins annotated within a particular pathway positively correlated with the clinical “distance” between APS subtypes, from the most clinically related C/MAPS vs tAPS to the most distant aPL vs C/MAPS suggesting an “evolution” from one phenotype to a more severe in terms of activation of specific pathways. Specifically notable is the higher activation of the NET signaling pathway in the aPL than in C/MAPS phenotype suggesting that the presence of aPL antibodies activates this immunothrombotic pathway. Conclusions. Plasma proteome of APS subtypes is characterized by alteration in several cellular processes, particularly receptor signaling, signal transduction, regulation of cellular differentiation, neutrophil, complement, coagulation and cytokine activation notable in all individuals with aPL-positivity. Pathways activated in the non-thrombotic (aPL) phenotype and escalating activation of several pathways from non-thrombotic to the most thrombotic (C/MAPS) phenotype provide important data for the understanding of APS pathogenesis and informing the model of APS-related immunothrombosis.

Topic: 24. Gene therapy, cellular immunotherapy and vaccination - Biology & Translational Research Background: Chimeric antigen receptor (CAR) T-cells has improved responses in refractory diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). Most CAR-T recipients experience cytokine release syndrome (CRS) related to T-cell activation and expansion of multiple cytokines. Differences in tumor biology between MM and DLBCL and how they contribute to varying rates of CRS are not well understood. Aims: We used multiplex proteomic profiling to evaluate differences in cytokine signatures between three CAR-T cell products. Methods: Between April – December 2022, 27 patients received CAR T-cell therapy and consented to the Yale School of Medicine hematologic disease tissue bank (HIC#1401013259). Three longitudinal cohorts were prospectively enrolled: patients who received (1) axicabtagene cileucel (axi-cel) for DLBCL refractory to 1-2 lines of therapy, (2) lisocabtagene maraleucel (liso-cel) for DLBCL refractory after two lines of therapy, and (3) idecabtagene vicleucel (ide-cel) for MM refractory after 4 lines of therapy. For each patient, the first sample was collected prior to lymphodepleting chemotherapy on day -5 with subsequent samples collected on days 0 (prior to CAR T-cell infusion) and 1, 2, 3, and 7 (after CAR T-cell infusion). Proteomic profiling was performed at Eve Technologies (Calgary, Alberta, Canada). The Human 71-Plex Discovery Assay measuring 71 total cytokines and chemokines was used to interrogate each sample time point. Statistical analysis was performed in GraphPad Prism (GraphPad Software, San Diego, CA) and R (R Core Team). Levels of individual proteins were compared using Wilcoxon tests. P-values <0.05 were statistically significant. Results: Among 12 patients with DLBCL, 7 received axi-cel, 5 received liso-cel, median age was 68 years (range 45-84), 9 (75%) were men, 6 (50%) had clinically bulky disease, and 9 (75%) required bridging chemotherapy. Six patients (50%) had any grade CRS, one patient receiving liso-cel had maximum grade 2 CRS, one patient receiving axi-cel had maximum grade 4 CRS, and 5 (42%) patients received IL-6 inhibition. Three patients (25%) had any grade ICANS, with 2 of those patients receiving axi-cel and having grade ≥ 3 ICANS. By 3 months of follow-up, the objective response rate was 83% (10/12). Among 15 patients with MM, the median age was 62 years (48-71), 8 (53%) were men, 4 (27%) had extramedullary disease, and 11 patients (73%) received systemic bridging therapy. Ten patients (67%) had any grade CRS with no patients having grade ≥ 3 CRS; 10 (67%) had grade 1 ICANS with two patients (13%) having grade ≥ 3 ICANS. Nine patients (60%) received IL-6 inhibition. All patients received growth factor support on day 7 prior to discharge. At 3 months of follow-up, the objective response rate was 67% (10/15). In a longitudinal analysis for all 3 CAR constructs, ide-cel was characterized by significantly higher levels of I-309, 6CKine, Fractaline, IFN-g, IL-10, IL-12p40, IL-13, IL-18, IL-9, M-CSF, MCP-2, MCP-4, MIP-1α, MIP-1β, MIP-1δ at ≥ 2 timepoints, compared to axi-cel and liso-cel (figure). In addition, stem cell factor (SCF) and TPO were significantly elevated in patients with MM at ≥ 5 timepoints both before and after ide-cel infusion. Summary/Conclusion This study provides pre-clinical evidence for a monocytic predominant inflammatory cytokine signature for patients receiving BCMA-CART invoking contribution by disease biology which may warrant alternative toxicity management. Baseline monocytic elevations may explain higher risk of Hemophagocytic lymphohistiocytosis (HLH) or Macrophage Activation Syndrome (MAS) among patients with MM. Further studies with larger cohorts of patients are needed to validate these findings.Keywords: Cellular therapy, Multiple myeloma, Diffuse large B cell lymphoma, CAR-T

Patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) often receive antibacterial prophylaxis. Antibacterial agents can cause elevations in the prothrombin time and international normalized ratio (INR). The impact of prophylactic antibacterials on the coagulation profiles and bleeding risk in patients with AML/MDS is unknown. We evaluated patients with AML or MDS who were being admitted to the hospital. The cohort was divided into two groups of patients: (1) those receiving and (2) those not receiving prophylactic antibacterials, at the time of admission. We conducted a retrospective cohort study of adult patients with AML/MDS admitted to Yale-New Haven Hospital between 2015-2019. The study was approved by the Yale Institutional Review Board. Inclusion criteria included patients >18 years old with a diagnosis of AML or MDS admitted to the hospital. We identified 150 individual patient encounters with active AML/MDS admitted to Yale-New Haven of which 32 occurred while on and 118 while off antibacterial prophylaxis. Median duration of pre-admission antibacterial exposure was 2 (range: 0.07-24) months. Patients on antibacterial prophylaxis had higher INR (median 1.14 vs. 1.03, p = 0.0002), and higher partial thromboplastin time prolongation (median 26.5 vs. 24.3, p < 0.0014), than patients without antibacterial prophylaxis. Patients without antibacterial prophylaxis had higher rates of bleeding using the ISTH-defined criteria (24.6% vs. 6.3%, p = 0.043), including higher rates of ISTH major (2 vs. 0) and clinically relevant bleeding (9 vs. 0). Patients with AML/MDS on antibacterial prophylaxis were more likely to have an abnormal coagulation profile when compared with their counterparts not on prophylaxis. Conversely, rates of bleeding were higher in patients not on prophylaxis. These data suggest that prophylactic antibacterials do not increase bleeding risk in patients with AML/MDS.

Introduction : Venous thromboembolism (VTE), encompassing deep venous thrombosis (DVT) and pulmonary embolism (PE), is a major public health hazard, with up to 30-50% of patients with unprovoked VTE experiencing a recurrent VTE event. These recurrent VTE events are associated with significant morbidity and mortality. However, transition strategies to second-line anticoagulation regimens following the first recurrence on anticoagulation have not been well studied. We sought to examine whether rates of the second VTE recurrence were different in those patients who changed their anticoagulation regimen from those who did not . Methods: With an IRB approval for the study, we created a database of all patients 18 years and older diagnosed with the first recurrent VTE at a large tertiary academic hospital between January 1, 2010, and December 31, 2019. The collected data was de-identified and compiled in a secure, standardized institutional database. We assessed the anticoagulation status at the time of and immediately following the first VTE recurrence, and identified patients who were switched to a different anticoagulant regimen. We used Fisher's exact test to evaluate proportions. Statistical significance was set at p<0.05. Results:We identified 138 patients with the first VTE recurrence. Of these patients, 114 (83%) developed DVT, 7 (5%) PE, and 17 (12%) both DVT and PE. Mean age was 63 years at the time of first VTE; 70 (51%) were female. Racial/ethnic representation was 84 (61%) White, 46 (33%) Black, and 133 (96%) non-Hispanic. The majority of patients had cardiovascular risk factors, including hypertension 80 (58%), hyperlipidemia 44 (32%), ordiabetes 40 (29%). Among 138 patients, 32 (23%) had active cancer, May-Thurner syndrome or inferior vena cava (IVC) atresia were reported in 13 (9%) of cases, and 21 (17%) underwent IVC filter placement at the time of the first VTE recurrence. The median follow-up time after diagnosis of a second VTE was 5 years. Following the first VTE recurrence, 19 (14%) of patients switched to a different anticoagulant agent, 7 (5%) had the dose of the anticoagulant adjusted, 1 (0.7%) was given a different INR target, and one had a change in the frequency of administration. The second VTE occurred in 49 (46%) patients who remained on the same anticoagulation regimen and in 3 (16%) who had the agent changed, in 5 who had dose of anticoagulant changed, in 1 (100%) each who had frequency or INR target changed. The association between unprovoked first VTE and the development of the second VTE was not significant (p= 0.85, Fisher's exact test). 49 (36%) of patients had at least one bleeding episode requiring the interruption of anticoagulation or hospitalization. Of those, 43 (88%) occurred while on an anticoagulant. Conclusion: The choice of an anticoagulant regimen after the first VTE recurrence does not impact the rate of the second recurrence.

Introduction: Localized intravascular coagulopathy (LIC) is a well-recognized, though poorly characterized complication of venous malformations (VM) that can lead to bleeding, thrombosis, and phlebolith formation. While LIC has classically been characterized by elevations in D-dimer and reductions in fibrinogen, no comprehensive studies of coagulation parameters in VM have been performed to date. Since 2021, all patients with VM undergoing evaluation for LIC in the Yale Vascular Malformations Program (VaMP) and the Yale Classical Hematology clinic have been subjected to an extensive set of coagulation tests to fully analyze LIC. Our aim was to use these laboratory test results to comprehensively characterize LIC in this population. Methods: We conducted a retrospective chart review of all VM patients presenting to the Yale VaMP and the Yale Classical Hematology clinic for assessment of LIC from 2021 to 2023. All included patients were evaluated for LIC using the following coagulation parameters: von Willebrand Factor (VWF) antigen, VWF activity, factor VIII (FVIII), alpha-2 antiplasmin (A2AP), plasminogen activator inhibitor-1 (PAI-1), thrombin-antithrombin complex (TAT), D-dimer (DD), fibrinogen, prothrombin time (PT), international normalized ratio (INR), and partial thromboplastin time (PTT). Measurements of VWF antigen, VWF activity, FVIII and A2AP were performed using an ACL TOP system (Instrumentation Laboratory; Bedford, MA, USA), while D-dimer and fibrinogen were measured using a BCS XP System (Siemens; Malvern, PA, USA) at our institution's clinical laboratory. PAI-1 and TAT were processed at national Clinical Laboratory Improvement Amendment-certified reference laboratories using ELISA-based assays. Baseline patient characteristics and coagulation test results were extracted via manual chart review. Data analysis was done using IBM SPSS statistics software and GraphPad Prism 9 software. Categorical variables were described using frequency and percentages, while quantitative variables were described using central tendency and dispersion measures. We performed univariate analysis using the Chi-square test. We also analyzed the coagulation tests using a correlation matrix. Statistical significance was set at p<0.05. This project was approved by our Institutional Review Board. Results: A total of 23 patients with VM were included in the analysis (Table 1). The mean age was 38 ± 16 years; the majority (82.6%) were female. The most common anatomic location was the head and neck (52.2%), while the most frequent extent of tissue involvement was muscle (54.5%), with most patients having a single lesion (59.1%) rather than multiple ones. No patients had venous thromboembolism. Normal DD and high TAT levels were observed in most patients (68.2% and 69.6%, respectively). VWF activity, VWF antigen, FVIII, PAI-1, and fibrinogen all were positively correlated (Figure 1). TAT was positively correlated with PAI-1 and inverselycorrelated withPT and INR. DD was positively correlated only with vWF activity. TAT and DD had a poor correlation; among patients with a normal TAT (n=7), 85.7% had a normal DD, while among patients with a normal DD (n=15), only 40% had a normal TAT. Three out of 4 (75%) patients with skin involvement had a high TAT with normal DD, while 2 out of 3 (66.7%) patients with visceral involvement had both high TAT and DD, although these patternswere not statistically significant (P=0.42 and 0.31, respectively). Among patients with muscle involvement (n=11), 45.5% had a high TAT and normal DD while 36.3% had both high TAT and DD. Conclusions: In this first comprehensive hematologic study of VM, we demonstrate that VM-related LIC is characterized by derangements of multiple coagulation parameters. Due to this, measurements of DD and fibrinogen alone may be inadequate for assessing LIC, and the addition of TAT and multiple other coagulation tests may yield a more complete picture of hemostatic derangements in LIC. A lack of correlation between DD and TAT is unexpected and merits further study. Differences in the depth of the VM tissue involvement and TAT/DD correlation may indicate a progression of coagulopathy related to the extent of VM but require further investigation in a larger study.

Topic: 24. Gene therapy, cellular immunotherapy and vaccination - Biology & Translational Research Background: Multiple Chimeric antigen receptor T-cell (CAR-T) products have been approved for the treatment of relapsed/refractory diffuse large B-cell lymphoma. These products have varying rates of toxicity including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Predictive biomarkers and targeted treatment strategies are limited for ICANS. Aims: We compared longitudinal cytokine profiles during the development of ICANS in patients receiving two different CD19-directed CAR T-cell therapies. Methods: Between April – December 2022, 12 patients received CD19-CAR T-cell therapy and consented to the Yale School of Medicine hematologic disease tissue bank (HIC#1401013259). Two longitudinal cohorts were prospectively enrolled: patients who received (1) axicabtagene cileucel (axi-cel) for DLBCL refractory to 1-2 lines of therapy and (2) lisocabtagene maraleucel (liso-cel) for DLBCL refractory after two lines of therapy. For each patient, the first sample was collected prior to lymphodepleting chemotherapy on day -5 with subsequent samples collected on days 0 (prior to CAR T-cell infusion) and 1, 2, 3, and 7 (after CAR T-cell infusion). Proteomic profiling was performed at each timepoint using Eve Technologies (Calgary, Alberta, Canada) using the Human 71-Plex Discovery Assay measuring 71 total cytokines and chemokines. Statistical analysis was performed in GraphPad Prism (GraphPad Software, San Diego, CA) and R (R Core Team). Protein levels were compared between patients who those who did or did not develop ICANS, as well as between the two CAR-T cell products using Wilcoxon tests. P-values <0.05 were statistically significant. Results: Among 12 patients with DLBCL, 7 received axi-cel, 5 received liso-cel, median age was 68 years (range 45-84), 9 (75%), 11 (92%) were considered double-expressor, 3 (25%) had double or triple hit pathology, 6 (50%) had clinically bulky disease, and 9 (75%) required bridging chemotherapy. Six patients (50%) had any grade CRS with one patient from the liso-cel cohort having maximum grade 2 CRS, one patient from the axi-cel cohort having maximum grade 4 CRS, and 5 (42%) patients requiring tocilizumab treatment. Three patients (25%) had any grade ICANS: two out the 7 patients who received axi-cel (28%) developed grade 3-4 ICANS, and one out of the 5 patients who received liso-cel (20%) developed grade 1 ICANS. By 3 months of follow-up, the objective response rate was 83% (10/12). Among patients who had developed ICANS, the levels of Eotaxin-2 were significantly decreased on timepoints of days 1, 2 and 7. The levels of interleukin (IL)-15, IL-27, and IL-6 were similar between patients who developed ICANS compared to those who did not. Overall, the levels of cytokines at multiple timepoints were similar between patients who received axicabtagene ciloleucel compared to those who received lisocabtagene maraleucel. Summary/Conclusion: Our results suggest that between patients who received lisocabtagene maraleucel or axicabtagene ciloleucel and between patients who did or did not develop ICANS, cytokine signatures were similar. This is despite lisocabtagene maraleucel and axicabtagene ciloleucel having historically different toxicity profiles yet similar clinical outcomes. ICANs may involve multifactorial etiologies independent of any single serum cytokine. Further studies with larger cohorts of patients are needed to further elucidate the pathophysiology of ICANS. Figure: Cytokine Levels of Eotaxin-2, IL-6, IL-15, and IL-27 Across Days -5 to Day 7 after receiving axi-cel or liso-cel for patients with no ICANS (0) or any ICANS (1)Keywords: Cytokine, Diffuse large B cell lymphoma, CAR-T, Cellular therapy

Objectives We sought to determine risk factors for iv iron infusion-related reactions (IRR), and identify strategies for iron repletion after IRR. Methods We conducted a retrospective chart review of patients treated in the classical hematology clinic at Yale Cancer Center (n = 330 consecutive patients) from 2016 to 2021, who received iv ferumoxytol (60.3%), iron sucrose (14.8%), or iron dextran (10.9%). Results The iv iron IRR was noted in 58 (17.6%) patients, 62.1% of whom had previously tolerated iv iron. The severity of IRR was mild in 22, moderate in 23, and severe in 11 patients. Most (72.4%) patients who experienced IRR tolerated a subsequent iv iron infusion. On multivariable analysis, a history of non-medication allergies was associated with greater odds of IRR (odds ratio [OR] 2.12, 95% confidence interval (CI): 1.16-3.87, p = .01). No patients with type AB blood, and few with type A blood (n = 6), had IRR; compared to type A or AB together, patients with type B (OR 5.00, 95% CI: 1.56-16.06, p = .007) or type O (OR 3.71, 95% CI: 1.44-9.55, p = .007) blood had greater odds of IRR. Conclusions This study highlights a possible association of blood type with iv iron IRR; prospective studies with larger patient numbers are warranted to explore this association.

INTRODUCTION Cirrhosis related coagulation derangements result in altered hemostasis. Endothelial markers such as von Willebrand factor (VWF) antigen and the factor VIII-to-protein C ratio (FVIII/PC) have prognostic significance in patients with cirrhosis. Additional endothelial markers have not been well described in patients with alcohol-associated cirrhosis. We performed plasma proteomic profiling in patients with alcohol-associated cirrhosis to gain insight into the potential roles of endothelial and hemostatic proteins associated with severity of cirrhosis. METHODS Two independent cohorts of patients with Child-Pugh class A (CPA) and C (CPC) alcohol-associated cirrhosis were recruited. Controls were patients without underlying liver disease. For plasma proteomic profiling, plasma supernatant was frozen, then sent to Eve Technologies (Calgary, Alberta, Canada). Linear discrimination analysis (LDA) was applied to the first cohort to identify a set of proteins that clustered patients based on the severity of liver disease (CPA vs CPC) and controls. Identified proteins were then validated using a second independent cohort of patients with alcohol-associated cirrhosis to determine if the protein signature was replicable. Boruta feature selection was performed on cohort 2 to identify candidate proteins to explain the differences in FVIII/PC ratio. A p-value of < 0.05 was considered statistically significant. RESULTS Cohort 1 included 13 patients: 4 CPA, 9 CPC (median age was 57; 4 women; 9 had dyslipidemia, 2 diabetes mellitus, 2 hypertension, and 2 chronic kidney disease). Cohort 2 included 12 patients: 7 CPA, 5 CPC (median age 50; 5 women; 7 had dyslipidemia, 1 diabetes mellitus, 1 hypertension and 0 chronic kidney disease). For cohort 1 LDA clustered patients based on CPA vs CPC with an endothelial, inflammatory and complement signature (fig.1). The proteins set that achieved robust LDA clustering of CPA, CPC, and control patients in cohort 1 included: sVCAM-1 and PAI-1 (endothelial markers); C3, C4, and CFH (complement cascade factors); IL-8 (inflammatory chemokine), NCAM (neural adhesion maker) and BDNF (neurotrophin); MPO (marker of neutrophilic activation); Eotaxin (eosinophil associated chemokine); MIP-1d (activator of T-cells and monocytes). The same protein profile applied to the validation cohort 2 was also able to cluster CPA, CPC, and control patients (fig. 2). Boruta feature selection for proteins of importance for the FVIII/PC ratio included sVCAM-1; CFI, C4b, C4, C5, CFB (complement factors); IL-6 (inflammatory cytokine), and VWF. CONCLUSIONS Using plasma proteomic profiling we describe a signature of endothelial, complement, hemostatic, and inflammatory activation that distinguishes the severity of liver disease in patients with alcohol-associated cirrhosis. Exploratory analyses suggest that endothelial and complement proteins may also contribute to the differences in the FVIII/PC ratio which has prognostic significance in patients with cirrhosis. Future work should continue to highlight the role of endothelium in the progression of liver disease and describe alternative prognostic markers to help guide clinicians. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Introduction: Adoptive cell therapy with chimeric antigen receptor (CAR) T-cells has improved responses in refractory diffuse large B-cell lymphoma (DLBCL) and multiple myeloma (MM). Most CAR-T recipients experience cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) - similar yet clinically distinct inflammatory syndromes related to T-cell activation and expansion of multiple cytokines. Differences in tumor biology between MM and DLBCL and how they contribute to differences in cytokine expression is not well understood. Given different CAR T-cell constructs have varying levels of activation and toxicity, cytokine profiles between products and between different disease entities may inform management. In this study, we used multiplex proteomic profiling to evaluate differences in plasma cytokine signatures between two CAR T-cell products and diseases. Methods: Between September 2021 and March 2022, 20 patients received CAR T-cell therapy and consented to the Yale School of Medicine hematologic disease tissue bank (HIC#1401013259). Two longitudinal cohorts were prospectively enrolled: (1) patients who received lisocabtagene maraleucel (liso-cel) for DLBCL refractory after two lines of therapy, and (2) those who received idecabtagene vicleucel (ide-cel) for MM refractory after 4 lines of therapy. For each patient, the first sample was collected prior to lymphodepleting chemotherapy on day -5 with subsequent samples collected on days 0 (prior to CAR T-cell infusion) and 1, 2, 3, and 7 (after CAR T-cell infusion). Plasma samples were processed and frozen within 1 hour of collection. Proteomic profiling was performed at Eve Technologies (Calgary, Alberta, Canada). The Human 71-Plex Discovery Assay measuring 71 total cytokines and chemokines was used to interrogate each sample time point. Statistical analysis was performed in GraphPad Prism (GraphPad Software, San Diego, CA) and R (R Core Team). Levels of individual proteins were compared using Wilcoxon tests. P-values <0.05 were considered statistically significant. Results: Among 13 patients who received liso-cel for DLBCL (including 2 with transformed follicular lymphoma and 3 with double/triple hit pathology), the median age was 66 years (44-82), 7 (54%) were males, 8 (62%) had KPS ≥ 90, 8 (62%) had bulky disease, median lines of therapy were 4 (2-10), and 11 (85%) received systemic bridging therapy. Seven patients (54%) had any grade CRS, with one patient having grade 3 CRS; 2 (15%) had grade 1 and 2 ICANS. Four patients (31%) received an IL-6 inhibitor. At 3 months of follow-up, the objective response rate was 77% (10/13), of whom two patients had a complete response and 60% (6/10) had any grade CRS. Among 7 patients who received ide-cel for MM, with R-ISS score of 1, 2, and 3 in 4 (57%), 1 (14%), and 2 (29%) patients, respectively, the median age was 61 years (54-79), 5 (71%) were males, 4 (57%) had KPS ≥ 90, 3 (43%) had extramedullary disease, median lines of therapy were 7 (4-13), and 5 patients (71%) received systemic bridging therapy. Six patients (86%) had any grade CRS with no patients having grade ≥ 3 CRS; 3 (43%) had grade 1 ICANS. Four patients (57%) received an IL-6 inhibitor. Five patients (63%) received growth factor support on day 7. At 3 months of follow-up, the objective response rate was 86% (6/7) of whom two patients had a complete response and 83% (5/6) had any grade CRS. In a longitudinal analysis, significantly higher levels of IL-3, IL-5, IL-6, IL-10, IL-15, IL-309, and TNFα were noted during CRS (panel 1). In a comparison between CAR constructs, ide-cel was characterized by significantly higher levels of Eotaxin-2, FLT-3L, IL-5, IL-6, IL-15, I-309, MCP-1, and MCP-4 compared to liso-cel (panel 2). Many of these elevated cytokine proteins are implicated as chemoattractants for other leukocyte subtypes including but not limited to neutrophils, monocytes, eosinophils which may contribute to inflammation and may modulate response, toxicity, or relapse. Conclusions: Ide-cel is associated with a distinct cytokine and chemokine signature compared to liso-cel. This study provides pre-clinical evidence for the role of IL-5 inhibitors to treat or prevent CRS following MM-directed CAR T-cell therapy. Further studies with larger cohorts of patients are needed to validate these findings. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

BACKGROUND. COVID-19 is a prothrombotic disease, characterized by endotheliopathy, hypercoagulability, and thromboembolic complications. We hypothesized that the pathogenesis of thromboembolism associated with COVID-19 might differ from thromboembolism in patients without COVID-19. In this study, we sought to evaluate the proteomic signatures of plasma from patients with venous thromboembolism with and without COVID-19.

Challenges in using cytokine data are limiting Coronavirus Disease 2019 (COVID-19) patient management and comparison among different disease contexts. We suggest mitigation strategies to improve the accuracy of cytokine data, as we learn from experience gained during the COVID-19 pandemic.

Pathologic immune hyperactivation is emerging as a key feature of critical illness in COVID-19, but the mechanisms involved remain poorly understood. We carried out proteomic profiling of plasma from cross-sectional and longitudinal cohorts of hospitalized patients with COVID-19 and analyzed clinical data from our health system database of over 3,300 patients. Using a machine learning algorithm, we identified a prominent signature of neutrophil activation, including resistin, lipocalin-2, HGF, IL-8, and G-CSF, as the strongest predictors of critical illness. Neutrophil activation was present on the first day of hospitalization in patients who would only later require transfer to the intensive care unit, thus preceding the onset of critical illness and predicting increased mortality. In the health system database, early elevations in developing and mature neutrophil counts also predicted higher mortality rates. Altogether, we define an essential role for neutrophil activation in the pathogenesis of severe COVID-19 and identify molecular neutrophil markers that distinguish patients at risk of future clinical decompensation.