Abstract Thromboembolic complication is common in severe coronavirus disease 2019 (COVID-19), leading to an investigation into the presence of prothrombotic antibodies akin to those found in heparin-induced thrombocytopenia (HIT). In a study of samples from 130 hospitalized patients, collected 3.6 days after COVID-19 diagnosis, 80% had immunoglobulin G (IgG) antibodies recognizing complexes of heparin and platelet factor 4 (PF4; PF4/H), and 41% had antibodies inducing PF4-dependent P-selectin expression in CpG oligodeoxynucleotide–treated normal platelets. Unlike HIT, both PF4/H-reactive and platelet-activating antibodies were found in patients with COVID-19 regardless of recent heparin exposure. Notably, PF4/H-reactive IgG antibodies correlated with those targeting the receptor-binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 spike protein. Moreover, introducing exogenous RBD to or removing RBD-reactive IgG from COVID-19 plasma or IgG purified from COVID-19 plasma significantly reduced their ability to activate platelets. RBD-specific antibodies capable of platelet activation were cloned from peripheral blood B cells of patients with COVID-19. These antibodies possessed sequence motifs in the heavy-chain complementarity-determining region 3 (HCDR3), resembling those identified in pathogenic HIT antibodies. Furthermore, IgG+ B cells having these HCDR3 signatures were markedly expanded in patients with severe COVID-19. Importantly, platelet-activating antibodies present in patients with COVID-19 were associated with a specific elevation of platelet α-granule proteins in the plasma and showed a positive correlation with markers for inflammation and tissue damage, suggesting a functionality of these antibodies in patients. The demonstration of functional and structural similarities between certain RBD-specific antibodies in patients with COVID-19 and pathogenic antibodies typical of HIT suggests a novel mechanism by which RBD-specific antibodies might contribute to thrombosis in COVID-19.
LTBK-01. PHASE 3 STELLAR STUDY SHOWS EFLORNITHINE IMPROVES OVERALL SURVIVAL (OS) AND PROGRESSION FREE SURVIVAL (PFS) IN PATIENTS WITH RECURRENT 2021 WHO ASTROCYTOMA, IDH-MUTANT GRADE 3
Abstract BACKGROUND Recurrent anaplastic astrocytoma (AA), a grade 3 brain cancer, remains an unmet medical need. STELLAR was a phase III randomized, open-label trial of eflornithine (ornithine decarboxylase inhibitor) with lomustine versus lomustine alone, originally for patients with recurrent AA. However, as the WHO definition of AA evolved during trial conduct (e.g., excluding IDH wild-type disease), we determined results in both the original ITT population and by revised molecularly defined WHO 2021 diagnoses in pre-planned analyses. METHOD Key eligibility: age ≥ 18, AA (2016 WHO criteria), first recurrence ≥ 6 months after radiation and temozolomide, KPS ≥ 70, no imaging findings consistent with grade 4 glioblastoma. Stratification: IDH, age, resection extent, and geography. Patients were randomized to Arm A: eflornithine (2.8 g/m2 TID Q 2/3 weeks) with lomustine (90 mg/m2 Q 6 weeks) or Arm B: lomustine (110 mg/m2 Q 6 weeks). Primary endpoint was OS. The pre-specified hazard ratio (HR) goal was 0.667 based on projected median OS (mOS) increase to 18 months from 12 months. RESULTS 343 pts (172/171 Arms A/B) were randomized (105 sites, 8 countries). ITT analysis found no difference between arms (mOS 23.4 vs. 20.3 months, HR = 0.94). However, a pre-specified subset analysis in IDH mutant, 2021 WHO-defined grade 3 astrocytoma (n=194), showed significant improvement with eflornithine (mOS 34.9 vs. 23.5 months, HR = 0.64, log rank p = 0.016) and PFS (15.8 vs. 7.2 months, HR = 0.58, log rank p = 0.015). No difference was observed in the IDH wild-type subset. AEs were consistent with historic data. CONCLUSION There was no difference in OS between arms in the ITT analysis. However, medically meaningful and statistically significant OS and PFS benefits were observed with eflornithine in the pre-planned analysis of patients with molecularly defined 2021 WHO CNS grade 3 astrocytoma.
LTBK-02. EVALUATION OF PAXALISIB IN GBM AGILE PHASE 3 REGISTRATION PLATFORM TRIAL FOR NEWLY DIAGNOSED AND RECURRENT GLIOBLASTOMA
Abstract GBM AGILE(NCT03970447) is a phase 2/3 Bayesian adaptive registration platform trial testing multiple therapies against a common control. Paxalisib, a PI3K/mTOR inhibitor, is the 3rd arm in the trial to conclude evaluation. METHODS Paxalisib was open to patients with newly diagnosed unmethylated (NDU) and recurrent (RD) glioblastoma, with three possible signatures: NDU, RD, and All(NDU+RD). Arm enrollment occurred Dec2020 through May2022. Control patients were enrolled from study initiation (July2019) and were treated with temozolomide(NDU) or lomustine(RD). GBM AGILE investigational arms have 1 or 2 stages, with adaptive randomization in stage 1 and fixed randomization if arms continue to stage 2. Efficacy is based on OS hazard ratio(HR) of Arm/Control. Efficacy goal is final Bayesian probability ≥ 98% for HR<1.00 in combined Stages. An Arm continues to Stage 2 if Bayesian predictive power (PP) ≥ 0.8. An Arm stops accruing in Stage 1 if it reaches maximal sample size(N) or does not meet a minimum efficacy threshold (PP<0.25 for all signatures when N>50). Clinical cut-off is 12 months after accrual stops. The maximum N for paxalisib was approximately 150(Stage 1) and 50(Stage 2). RESULTS After paxalisib reached >150 patients in Stage 1, accrual stopped [Paxalisib/control N 54/75(NDU), 100/188(RD)]. Neither PP thresholds for moving to Stage 2 nor stopping for minimum efficacy were met. Following an unplanned public disclosure that the arm did not continue to stage 2, clinical cut-off for final analysis (planned May2023) was updated to public disclosure date (August2022). At final analysis mean HRs were 0.89(NDU), 1.25(RD), 1.05(All), probabilities of HR<1.00 of 0.72(NDU), 0.076(RD), 0.398(All). Model estimated median OS paxalisib/control (months) were 14.77/13.84(NDU) and 8.58/10.06(RD). CONCLUSION Paxalisib did not show survival benefit over cumulative control in final primary analysis; additional secondary analyses are being considered. GBM AGILE continues to rapidly and efficiently assess therapies in ND and RD glioblastoma.
An Annual Review of Important Apheresis Articles From the American Society for Apheresis Attending Physician Subcommittee
ABSTRACTIn this first annual review article, the American Society for Apheresis (ASFA) Attending Physician Subcommittee (APSc) of the Physicians' Committee (PC) curated key apheresis literature in 2023 and presented their choices for the 10 most seminal apheresis articles. PubMed and OVID search engines were used to identify manuscripts from four topic areas: donor apheresis, therapeutic apheresis, education, and cellular therapy. To further identify seminal criteria, they had to present at least one of the following: novel findings, practice‐altering outcomes, international scope, randomized controlled trial, relevant to current clinical practice, and/or provide evidence for category III or IV indications based on the ASFA ninth special issue of the Guidelines on the Use of Therapeutic Apheresis in Clinical Practice‐Evidence‐Based Approach. Inclusion criteria included: full‐length, peer‐reviewed, English language, and human subjects. Case reports, review articles, and meta‐analyses were excluded.
Abstract 4140462: Effects of Right Ventricular vs. Conduction System Pacing on Left Ventricular Systolic and Diastolic Function Reserve and Pulmonary Gas Exchange During Exercise Stress in Pacemaker Dependent Patients with Normal Left Ventricular Ejection
Background: Right ventricular pacing (RVP) can have adverse cardiac effects and cause pacing induced cardiomyopathy (PiCM). His bundle pacing (HBP)&Left Bundle Branch area pacing (LBBAP) mimic physiologic conduction (PhysioP) and maintain biventricular synchrony. Hypothesis and Aims: Reduced left ventricular (LV) systolic function reserve in the presence of normal baseline LV ejection fraction (EF) could precede development of RV PiCM. Our aim was to compare the effects of RVP vs. PhysioP on bicycle exercise cardiopulmonary performance in patients with normal LVEF who required pacing for bradyarrhythmias. Methods: Patients with sinus rhythm and RVP or PhysioP&ventricular pacing burden of >70% who completed cardiopulmonary exercise test and simultaneous stress echocardiography (SE) were included. Pulmonary gas exchange was calculated using Ventilation/CO2 production at rest and during exercise. Changes in LV size, EF, longitudinal strain and diastolic function and gas exchange parameters were compared post and pre exercise in the 2 groups. Results: 25 of 29 patients completed the study [68 ± 23 yrs, 48% M; LVEF 56±5%, 11 RVP, 14 PhysioP]. There was no difference in baseline demographic&clinical variables, exercise duration, rest and peak heart rate and blood pressure between 2 groups. Pacing duration was 2.61±1.48 yrs in RVP vs. 0.84±0.67 yrs (p=0.003) in the Physio group. Resting echocardiographic parameters ( Table 1A) were comparable. Compared to RVP, reduction in LV end-diastolic volume (EDV) 3.4±14.1 ml vs. -23.1±18.1ml, p=0.006)&LV end-systolic volume (ESV -5.7±11.6 ml vs. -18.0±9.5ml, p=0.01) was more pronounced in the PhysioP group. Changes in LVEF, LV strain&diastolic function were not different between the 2 groups ( Table 1B ). There were no significant differences in changes in pulmonary gas exchange parameters in the 2 groups. Conclusions: In patients with normal LVEF and pacemaker dependent, RVP is associated with impaired but PhysioP with preserved LV systolic function reserve, which can be detected by exercise SE. SE may help identify patients at risk for RV PiCM. Benefit of PhysioP needs to be determined by larger studies with longer follow-up.
Identification of genomic biomarkers of disease progression and survival in primary CNS lymphoma
Abstract The determination of the genetic subtypes of primary central nervous system lymphoma (PCNSL) and their relationship to differential chemoimmunotherapeutic response has not been established. There is a particular need for genomic biomarkers that identify patients with newly diagnosed PCNSL at high risk of early progression and death. We applied targeted next-generation sequencing for detection of recurrent single-nucleotide variants, copy number alterations, and zygosity abnormalities in diagnostic specimens from 78 patients with PCNSL treated with a standard methotrexate-based regimen, to identify prognostically significant molecular subgroups. All patients received induction immunochemotherapy, and 44 proceeded to dose-intensive consolidation. Genomic aberrations at 4 loci were associated with 91% of lymphoma progression events and all 15 deaths: (1) chromosome 6p copy-neutral loss of heterozygosity (CN-LOH) or focal homozygous deletion (HD) at 6p21.3, and mutations of tumor suppressor genes (2) BTG1, (3) ETV6, and (4) TP53. Cox regression multivariate analysis demonstrated a high risk of progression in patients with aberrations at these loci. Genomic aberrations at these loci were also associated with significantly shorter survival. Lower expression of HLA-DR was associated with 6p CN-LOH/6p21.3 HD and inferior prognosis. These genomic aberrations identify a high-risk molecular subgroup that may inform risk stratification in PCNSL. Further elucidation of the mechanisms of therapeutic resistance associated with the high-risk genetic phenotype is requisite to facilitate precision medicine and progress in therapy.
Abstract A030: Rapid extraction and detection of extracellular vesicle-derived PD-L1 in a microfluidic platform
Abstract Background. Extracellular vesicles (EV) are emerging as new biomarkers for cancer diagnostics and therapeutic monitoring1. For example, in patients that receive PD1/PD-L1 immune checkpoint inhibitors (a key pillar of cancer immunotherapy), circulating EV-derived PD-L1 is gaining attention as a non-invasive biomarker for therapeutic efficacy. Standard methodologies to measure EV-derived PD-L1 requires ultracentrifugation to first separate EVs and then quantify those that express PD-L1 using nano flow cytometry. These are tedious processes that require trained technologists in centralized facilities, which is a key barrier to frequently monitoring EV-based biomarkers. Yet, frequent monitoring is crucial to quickly identify and stop an ineffective therapy while more fruitful options are still available. Method. To bridge the gap, we develop a proof-of-concept digital microfluidic (DMF) device that can separate EVs directly from biofluids and quantify PD-L1+ EVs automatedly. Briefly, DMF device supports automatedly droplet handling, including droplet transport, splitting and mixing, based on electrowetting principles2. Immunomagnetic beads were used to capture EVs from biofluids, and EVs were then detected by electrochemical sensors inserted into the device. These tips of the electrochemical sensors were modified with gold nanoparticle self-assembled layers to enhance target binding, and CD9 antibodies were immobilized on the tips to bind to EVs. We then used anti-PD-L1 as secondary antibodies for target detection. Differential Pulse Voltammetry (DPV)3 were performed to obtain the results. Results. We used the DMF device to extract 109- 1011 #/mL EVs secreted by a human breast cancer cell line (MDA-MB-231). Briefly, 10 mL of cell culture media was loaded into the DMF device, and the sample was mixed and incubated with a 10 mL droplet of immunomagnetic beads to capture EVs. After 5 min, EVs were eluted in 20 mL of elution buffer, and the beads were discarded. We estimated the number of EVs using Nanoparticle Tracking Analysis; the number of EVs extracted on-chip was comparable with those that were extracted using standard in-tube method. We also verified the purity of the EVs extracted on-chip using Western Blot. Our results showed that the electrochemical sensors can detect as low as 104 #/mL PD-L1+ EVs, with a linear range of 104 – 107 #/mL (R2=0.9701). The entire process can be completed within 1 hour. Conclusion. We integrated automated EV extraction and their surface marker detection in a single DMF device. Our next step is to extract and detect EV-based biomarkers from plasma samples. This platform holds promise for the regular monitoring of EV-based biomarkers that are indicators of therapeutic responses in patients that receive cancer immunotherapies. References1. F. Lucien, D. Gustafson, M. Lenassi et al, Journal of extracellular vesicles 12 (12), 12385 (2023). 2. Y. Zhang and Y. Liu, Sensors & Diagnostics (2022). 3. Y. Zhang, J. Liu, T.-W. Lo et al, Biosensors and Bioelectronics: X, 100490 (2024). Citation Format: Ting-Wen Lo, Yuqian Zhang, Jing Liu, Yohan Kim, Haidong Dong, Fabrice Lucien, Yuguang Liu. Rapid extraction and detection of extracellular vesicle-derived PD-L1 in a microfluidic platform [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr A030.
Nomenclature for human and animal fungal pathogens and diseases: a proposal for standardized terminology
ABSTRACT Medically important pathogenic fungi invade vertebrate tissue and are considered primary when part of their nature life cycle is associated with an animal host and are usually able to infect immunocompetent hosts. Opportunistic fungal pathogens complete their life cycle in environmental habitats or occur as commensals within or on the vertebrate body, but under certain conditions can thrive upon infecting humans. The extent of host damage in opportunistic infections largely depends on the portal and modality of entry as well as on the host’s immune and metabolic status. Diseases caused by primary pathogens and common opportunists, causing the top approximately 80% of fungal diseases [D. W. Denning, Lancet Infect Dis, 24:e428–e438, 2024, https://doi.org/10.1016/S1473-3099(23)00692-8 ], tend to follow a predictive pattern, while those by occasional opportunists are more variable. For this reason, it is recommended that diseases caused by primary pathogens and the common opportunists are named after the etiologic agent, for example, histoplasmosis and aspergillosis, while this should not be done for occasional opportunists that should be named as [causative fungus] [clinical syndrome], for example, Alternaria alternata cutaneous infection. The addition of a descriptor that identifies the location or clinical type of infection is required, as the general name alone may cover widely different clinical syndromes, for example, “rhinocerebral mucormycosis.” A list of major recommended human and animal disease entities (nomenclature) is provided in alignment with their causative agents. Fungal disease names may encompass several genera of etiologic agents, consequently being less susceptible to taxonomic changes of the causative species, for example, mucormycosis covers numerous mucormycetous molds.
The applications of spinal cord stimulation in diseases with motor disorders, pain, and cognitive disturbance
Spinal cord stimulation (SCS), first used for pain relief in 1967, serves as an invasive neuromodulation with the targeted delivery of stimulations and the alertness of neural activities. Based on the gate-controlled theory of pain and multiple research studies, the application of SCS to motor recovery, pain relief, and sensory and cognitive restoration has been shown to be significant. Considering that movement disorders and pain are complications of various diseases, the categories, applications, and technical operation of SCS are coming of age. In terms of its impact on the immune system, SCS alters the trajectory of neurological diseases by modulating local immune responses through immunomodulatory mechanisms that vary depending on the different patterns of SCS. In addition to existing targets, the combinations of SCS and emerging techniques deepen the research at the molecular level, contributing to the exploration of potential targets and novel treatments. However, to secure a place in the future trend of non-invasive and precise treatment, it is necessary to improve SCS in terms of mechanism research, cost reduction, and application to more diseases.
A cohort study examining predictors of stroke and bleeding among people with congenital heart disease and atrial fibrillation
Abstract Background Congenital Heart Disease (CHD) is associated with development of atrial fibrillation (AF) at an early age. With increased survival of this cohort into adulthood, the prevalence of concurrent CHD and AF is expected to increase over the next several decades. Little is known about the utility of clinical risk factors or prediction models in determining bleeding or stroke rates in adults with CHD and AF. Purpose This study aims to measure the performance of the CHADSVASC and HASBLED scores in a cohort of people with CHD. The association between traditional stroke and bleeding risk factors, as well as CHD-specific factors, will be quantified. Methods Patients age 18 or older attending one of three centers in the USA were included in this study if they had a history of AF on ECG, holter monitor or device interrogation, in addition to a diagnosis of Tetralogy of Fallot (TOF), Double Outlet Right Ventricle (DORV), or Pulmonary Atresia with Intact Ventricular Septum (PA-IVS). Outcomes were major bleeding event, and stroke rate. Analysis was conducted using cox univariable regression controlling for current age. Receiver operator curve and c-statistics were produced for the CHADSVASC and HASBLED scores respectively. Results 326 people were included in this study, of whom 161 (49.5%) had TOF secondary to Pulmonic Stenosis, 126 (38.8%) had TOF secondary to Pulmonary Atresia, 25 (7.7%) had DORV, and 155 (47.7%) had PA-IVS. 227 people used warfarin (79.4%), 28 (9.8%) used apixaban, 9 (3.1%) used Rivaroxaban, 3 (1%) used Edoxaban, and 5 (1.7%) used Enoxaparin for a period of at least 30 days during the study. 13 (4.5%) people didn’t receive anticoagulation during the study. 26 people had a stroke (8.8%) while 85 people (28.6%) had a major bleeding event. Only the CHADSVASC score was significantly associated with stroke rates (HR 2.103, 95% CI 1.555 to 2.844, p<0.001). Clinical variables, such as subtype of CHD, prior conduit placement or unifocalization were not associated with stroke or major bleeding events. C-statistic for the CHADSVASC score in predicting stroke events was 0.755 (Figure 1). C-statistic for the HASBLED score in predicting major bleeding was 0.442 (Figure 2). Conclusions Among people with CHD and AF, the CHADSVASC score can robustly predict stroke events. Other clinical variables are less valuable in predicting either bleeding or strokes. The HASBLED score likely doesn’t have a role in predicting major bleeding episodes in this cohort.