Citations

Abstract Aims Type 2 myocardial infarction due to myocardial oxygen supply–demand imbalance is associated with poor outcomes. There are no guidelines to inform care for these patients. The consensus on the assessment and management of type 2 myocardial infarction is gained. Methods and results An international e-Delphi study including experts in type 2 myocardial infarction identified through systematic review was conducted. Participants were asked to describe their approach to (i) definition and diagnosis, (ii) risk stratification, (iii) assessment of coronary artery disease and cardiac function, (iv) specialty management, (v) treatment and secondary prevention, and (vi) communication and rehabilitation. Statements generated in round one were circulated, with consensus defined a priori as ≥70% agreement on a 5-point Likert scale. Where no consensus was reached, statements were amended and recirculated for a final round. The response rate was 56% (38/68), 54% (37/68), and 72% (49/68) in the first, second, and third rounds, respectively. Following the first round, 67 unique statements were generated across six domains. Overall, consensus was achieved on 64% (43/67) of statements. Consensus was achieved for 42% (5/12) of statements on the diagnosis of type 2 myocardial infarction, 75% (3/4) on risk stratification, 50% (9/18) on the assessment of coronary artery disease and cardiac function, 60% (6/10), on specialty management, 100% (9/9) on treatment and secondary prevention, and 79% (11/15) on communication and rehabilitation. Conclusion Consensus was obtained across a number of domains for the assessment and management of patients with type 2 myocardial infarction. However, there was limited agreement amongst experts on the diagnostic criteria, which may benefit from refinement.

Abstract Molecular characterization of high-grade B-cell lymphoma, not otherwise specified (HGBCL-NOS), is hindered by its rarity, evolving definition, and poor diagnostic reproducibility. To address this challenge, we analyzed 92 HGBCL-NOS tumors collected across Lymphoma/Leukemia Molecular Profiling Project sites. Leveraging comparison cohorts of diffuse large B-cell lymphoma, NOS (DLBCL-NOS) and Burkitt lymphoma (BL), and molecular frameworks described in these entities, our analysis revealed a heterogenous molecular landscape, reminiscent of DLBCL-NOS but with an enrichment of BL features. By cell-of-origin classification, 59% were germinal center B-cell–like (GCB), and 25% were activated B-cell–like (ABC). LymphGen, a genetic classifier for DLBCL-NOS, assigned a genetic subtype to 34% of HGBCL-NOS. Although classification rate was lower than in DLBCL-NOS (66%), assigned subtypes spanned the spectrum of LymphGen classes, including 31% of ABCs classified as MCD. Features differentiating HGBCL-NOS from DLBCL-NOS included MYC rearrangement (47% vs 6%); dark zone signature (DZsig) expression (45% vs 7%); and more frequent mutation of ID3, MYC, CCND3, and TP53, all common to BL. A genetic classifier that differentiates DLBCL-NOS from BL classified 53% of DZsig+ tumors as BL-like, and those classified as DLBCL-like were frequently BCL2-rearranged. Among DZsig− GCB tumors, 95% were DLBCL-like. Centralized pathology review reclassified almost half of tumors as DLBCL-NOS but did not identify a more homogenous HGBCL-NOS population, with no difference in features between confirmed and reclassified tumors. In conclusion, molecular testing enables a subset of HGBCL-NOS to be assigned to established categories. Based on rarity and diagnostic challenges, broader inclusion of HGBCL-NOS should be considered in biomarker-driven DLBCL trials.

Abstract New technologies enabling access to high-sensitivity cardiac troponin (hs-cTn) assays at the point of care (POC) are available for routine use. POC technology can accelerate cardiac troponin testing within the hospital setting and support testing in other healthcare environments. Pre-analytical and analytical issues unique to POC testing are discussed. The opportunities and the evidence needed to support the routine use of hs-cTn POC assays in clinical care are outlined. Based on recent developments, the potential impact of hs-cTn at the POC in multiple clinical settings is described, and a roadmap of the steps required for successful implementation is provided.

10512 Background: Polygenic risk scores (PRSs) combine information from single-nucleotide polymorphisms (SNPs) across the genome to explain substantial genetic breast cancer (BC) susceptibility. Previous studies have demonstrated that a multiple-ancestry PRS (MA-385) based on 56 ancestry-informative and 329 BC-associated SNPs is accurate for diverse populations and ranks among the most important known factors affecting the risk of BC development. However, medical guidelines call for more evidence before endorsing the clinical use of PRS, including studies to evaluate possible interactions of SNPs with environmental and hormonal risk factors. Here, we use longitudinal outcomes from the UK Biobank (UKB) to explore interactions of MA-385 and the five most informative individual BC-associated SNPs with the widely used Tyrer-Cuzick (TC) risk model and individual TC risk factors. Methods: The study cohort included 197,509 female UKB participants with no history of cancer at the time of study enrollment. We used Cox proportional hazards models to test associations of MA-385, individual BC SNPs, TC, and individual TC risk factors with BC outcomes. Effect modification of MA-385 and individual SNPs by clinical risk factors was evaluated by including interaction terms in the models. All models were adjusted for age at UKB enrollment and 10 principal components. Hazard ratios (HRs) and 95% confidence intervals (CIs) are reported per standard deviation, and significance tests were performed using two-sided p-values based on likelihood-ratio test statistics. Results: After a median follow-up of 11.8 years, 7,419 (3.8%) participants were diagnosed with BC.In a model including both MA-385 and TC, MA-385 was a significantly better predictor of BC development (HR = 1.56; 95% CI 1.53-1.60, p = 3.2 x 10 -329 ) over the TC model (HR = 1.21; 95% CI 1.18-1.23; p = 5.4 x 10 -69 ). We found no evidence of interaction between MA-385 and TC ( p = 0.31) , nor between individual SNPs and TC. After Bonferroni adjustment for multiple testing (102 tests), we found no evidence of interaction between MA-385 or individual SNPs with clinical TC factors. The strongest evidence for interaction was found between a BC SNP on chromosome 2 (rs13387042) and age at UKB enrollment (unadjusted p = 0.002; Bonferroni adjusted p = 0.23). Conclusions: In a longitudinal analysis of UKB, MA-385 was a highly significant predictor of BC risk and substantially improved prediction over TC. In contrast, interactions of MA-385, and individual BC SNPs, with TC and individual clinical factors in the TC model were not statistically significant. Clinical TC factors have minimal, if any, impact on the strength of the association between MA-385 and BC. These results may help to alleviate concerns expressed in guidelines that SNPs interact with environmental or hormonal risk factors.

ABSTRACT LYRM7‐associated mitochondrial complex III deficiency has classically been described in the literature as a childhood‐onset episodic leukoencephalopathy with neuroimaging findings of cavitating periventricular and subcortical white matter loss. We describe the heterogeneous clinical and neuroimaging profile of six individuals from south India with the specific homozygous pathogenic variant in the LYRM7 gene (c.2T>C, (p.Met1?)). This is a retrospective case series featuring six cases (four pediatric, one adult, and one adolescent‐onset) with the pathogenic start loss LYRM7 variant. The spectrum of neurologic manifestations and brain imaging findings documented over multiple clinic visits was analyzed and described. Vision loss and lactic acidosis were seen in all but one individual. A novel phenotype with adult‐onset isolated bilateral simultaneous optic neuropathy was noted. Characteristic cavitating leukoencephalopathy in supratentorial white matter was seen in the brain MRI of three out of six individuals. A comprehensive description of our cases along with the previously published cases is provided in the table highlighting the clinical and imaging variability and the disease course. The phenotype of adult‐onset isolated acute optic neuropathy can be a manifestation of LYRM7‐related mitochondrial disorder. LYRM7‐associated Mitochondrial Complex III deficiency should be considered in the differential diagnosis of para‐ and post‐infectious demyelinating/inflammatory disorders, especially if there is a background of variable developmental delay, recurrence of the episodes, family history, cystic changes in cerebral white matter on imaging, or poor response to immunomodulation. The case series also exemplifies the intra‐and inter‐familial variability seen with this rare disorder.

ABSTRACT Hypoxic stress responses are essential for cellular and organismal survival and drive gene regulation across diverse biological pathways, including cell cycle progression and energy metabolism. Here, we show that topoisomerase IIβ (TOP2B) regulates DNA topology and transcription of hypoxia-inducible genes (HIGs) in a DNA-dependent protein kinase (DNA-PK)-dependent manner. Integrated cellular, biochemical, and genomic analyses reveal an antagonistic yet correlated relationship between TOP2B and DNA-PK activities. Under normoxic conditions, TOP2B associates with HIGs and represses transcription by suppressing DNA negative supercoiling formation and accessibility. Under hypoxic exposure, TOP2B dissociates from HIGs, while DNA-PK and HIF1α are recruited to activate HIGs. Notably, DNA-PK is required for the repressive function of TOP2B, as DNA-PK knockout abrogates TOP2B release and activity, resulting in elevated expression of a number of HIGs. Mechanistically, DNA-PK phosphorylates TOP2B at T1403, stimulating its catalytic activity to restrain DNA unwinding and accessibility, thereby suppressing HIG transcription. Collectively, these findings identify a novel role for TOP2B and DNA-PK-mediated regulation of TOP2B as key transcriptional regulators of HIG expression. We propose that phosphorylation-dependent modulation of TOP2B activity is coordinated with transcriptional states and determines DNA topology to regulate Pol II transcription.

Introduction Plasmablastic lymphoma (PBL) is a rare aggressive subtype of lymphoma. It is more common in HIV positive patients, and is often associated with Epstein-Barr virus (EBV) and MYC rearrangements. PBL is characterized by markers of plasmacytic differentiation including CD138 and MUM1/IRF4, and loss of B-cell markers such as CD20, which suggests a cell of origin similar to that of multiple myeloma (MM) or activated B-cell-like (ABC) diffuse large B-cell lymphoma (DLBCL). The standard of care for PBL is CHOP-based chemotherapy but this is frequently not curative. Other than EBV-negative status, which defines a high-risk group, no other biological features have been discovered that are associated with outcomes. Methods Here, we provide a comprehensive analysis of the genomic and transcriptomic landscape of PBL using a collection of 176 exomes and genomes (n=55 new, contributed by Lymphoma/Leukemia Molecular Profiling Project [LLMPP] sites and centrally reviewed by the LLMPP pathology panel [WHO 2016]; n=121 previously published [PMID: 33225311, 33951889, 34465776, 34714908]), 65 transcriptomes (n=44 new; n=21 published) and 37 in situ single cell transcriptomic profiles (CosMx Spatial Molecular Imager) from archival diagnostic tissue biopsies. Somatic mutations (SNVs/Indels) were identified using an ensemble of four variant callers (Strelka2, Lofreq, Mutect2, SAGE). Salmon and DESeq2 were used to identify differentially expressed genes. This multi-omics dataset was compared to other known B-cell malignancies including 92 MM, 238 Burkitt lymphomas (BL), and 208 DLBCLs. Cell segmentation of the CosMx data was performed using Baysor and downstream analyses were conducted using the Seurat workflow. For functional validation, cell viability assays (CellTiter-Glo Luminescent Assay) were conducted in the PBL cell line, PBL-1, and 4 control DLBCL cell lines. Results Within the cohort, 63% (106/169) of primary PBL cases were EBV-positive (EBV+) and 57% (82/144) harbored MYC rearrangements (MYC+). When stratifying patients by EBV and MYC rearrangement status, mutations in different genes were enriched in each group: STAT3 occurred in 55% (29/53) of EBV+/MYC+ PBLs; NOTCH1 in 19% (7/36) of EBV+/MYC-; MYC in 24% (6/25) and TP53 in 40% (10/25) of EBV-/MYC+ tumors; TET2 was mutated in 38% (9/24) and KRAS in 25% (6/24) of EBV-/MYC- PBLs. EBV-/MYC+ tumors represented a subgroup of patients with dismal outcomes. The 2-year overall survival (OS) of these patients was 22% compared to 61%, 78%, and 54% of EBV+/MYC+, EBV+/MYC-, and EBV-/MYC- PBL patients, respectively (log-rank test p-adj. < 0.05). Consistent with previous studies, we observed recurrent mutations affecting JAK-STAT (STAT3, SOCS1, SOCS3, DUSP2) in 41% of cases and RAS-RAF (NRAS, KRAS, BRAF) signaling in 38% of all PBLs. In contrast to ABC-DLBCL, very few mutations occurred in the NF-κB signalling pathway. Accordingly, PBL showed marked downregulation of genes involved in B-cell receptor and NF-κB signaling. Consistent with the lack of reliance on these pathways, functional analyses in PBL-1 showed resistance to treatment to ibrutinib as well as PI3K- and MALT1-inhibitors. Moreover, constitutive expression of the IκBα super-repressor did not affect viability of PBL-1 cells. In situ single cell transcriptomic data analyses showed a sparse tumor microenvironment (TME) in PBL, with the primary non-malignant cell types being, on average, 10% macrophages, 7% NK/T cells, and 4% stromal cells of all represented cell types. EBV+/MYC+ tumors displayed a more abundant immune cell population with higher levels of macrophages (median 12%) and NK/T cells (median 9%), whereas EBV-/MYC- tumors were composed of the lowest levels of immune cells (median 4% macrophages and 1% NK/T cells). With respect to malignant cell phenotypes, we noted a novel population of SPP1-expressing cells that were enriched in EBV+/MYC+ tumors and a population of CD44-expressing cells that were enriched in EBV+/MYC- tumors. Conclusion Here we present novel subgroups of PBL with unique biology and clinical outcomes. We show that PBL does not rely on B-cell receptor signaling, instead relying on potentially targetable vulnerabilities in JAK-STAT, NOTCH, and RAS-RAF signaling according to EBV positivity and MYC rearrangement status. Lastly, we provide insight into the TME of PBL and demonstrate a novel population of SPP1 and CD44 expressing malignant cells in EBV+ tumors.

Abstract Current standard of care for IDH-wildtype glioblastoma (GBM) includes maximal safe resection, adjuvant radiation, and chemotherapy with the alkylating agent temozolomide. A subset of gliomas treated with temozolomide develop somatic hypermutation with a predominance of C>T transitions due to the alkylation effects on DNA. However, the frequency of occurrence, clinical ramifications, and predictive biomarkers for developing temozolomide-induced hypermutation (TMZ-HM) in GBM are unknown. Here we performed comprehensive histopathologic, genomic, and epigenomic evaluation of paired initial and recurrent GBM from 106 patients. Seven patients (7%) developed hypermutation at time of first recurrence, while an additional five patients (5%) developed hypermutation at a subsequent recurrence. Patients who developed TMZ-HM had a significantly longer interval between initial surgery and first recurrence (27.8 vs. 9.9 months, p<0.001). In contrast to IDH-mutant gliomas where TMZ-HM is associated with poor prognosis, those patients with IDH-wildtype GBM who developed TMZ-HM had significantly longer overall survival from both initial surgery (67.9 vs. 20.3 months, p<0.001) and from time of recurrence after development of hypermutation (30.9 vs. 9.5 months, p=0.001). There was no difference in oncogenic alteration frequency in initial GBM that subsequently developed TMZ-HM. However, 4 specific CpG sites out of 12 total interrogated sites in the promoter region of MGMT (a DNA repair enzyme) and 5 specific CpG sites in the promoter region of KCNQ1DN (a negative regulator of c-Myc) were significantly more hypermethylated in those GBM that developed TMZ-HM. We then generated a weighted risk score across these CpG sites that can be used to prospectively identify GBM likely to develop TMZ-HM associated with favorable survival. In summary, patients with GBM that develop TMZ-HM follow a more favorable clinical course, and specific MGMT and KCNQ1DN promoter hypermethylation patterns could serve as a biomarker to identify these patients who may potentially benefit from extended alkylating chemotherapy treatment.