Citations

AbstractThe World Health Organization (WHO) classification system categorizes advanced systemic mastocytosis (SM‐Adv) into aggressive SM (ASM), mast cell leukemia (MCL), and SM with associated hematological neoplasm (SM‐AHN). By contrast, the International Consensus Classification (ICC) requires “immature” MC cytomorphology for the diagnosis of MCL and limits SM‐AHN to myeloid neoplasms (SM‐AMN). The current study includes 329 patients with SM‐Adv (median age 65 years, range 18–88; males 58%): WHO subcategories SM‐AHN (N = 212; 64%), ASM (N = 99; 30%), and MCL (N = 18; 6%); ICC subcategories SM‐AMN (N = 190; 64%), ASM (N = 99; 33%), and MCL (N = 9; 3%); WHO‐defined MCL with “mature” MC cytomorphology and SM‐AHN associated with lymphoid neoplasms were operationally labeled as “MCL‐mature” (N = 9) and SM‐ALN (N = 22), respectively, and distinguished from ICC‐defined MCL and SM‐AMN. Multivariable analysis that included the Mayo alliance risk factors for survival in SM (age >60 years, anemia, thrombocytopenia, increased alkaline phosphatase) revealed more accurate survival prediction with the ICC versus WHO classification order: (i) survival was significantly worse with MCL‐immature versus MCL‐mature (hazard ratio [HR] 15; p < .01), (ii) prognostic distinction between MCL and SM‐AHN/AMN was confirmed in the context of ICC (HR 9.3; p < .01) but not WHO classification order (p = .99), (iii) survival was similar between MCL‐mature and SM‐AMN (p = .18), and (iv) SM‐AMN (HR 1.7; p < .01) but not SM‐ALN (p = .37) was prognostically distinct from ASM. The current study provides evidence for the independent prognostic contribution of both the ICC system for SM‐Adv and the Mayo alliance risk factors for survival in SM.

Abstract Multiple myeloma (MM) is a malignancy that is often driven by MYC and that is sustained by IRF4, which are upregulated by super-enhancers. IKZF1 and IKZF3 bind to super-enhancers and can be degraded using immunomodulatory imide drugs (IMiD). Successful IMiD responses downregulate MYC and IRF4; however, this fails in IMiD-resistant cells. MYC and IRF4 downregulation can also be achieved in IMiD-resistant tumors using inhibitors of BET and EP300 transcriptional coactivator proteins; however, in vivo these drugs have a narrow therapeutic window. By combining IMiDs with EP300 inhibition, we demonstrate greater downregulation of MYC and IRF4, synergistic killing of myeloma in vitro and in vivo, and an increased therapeutic window. Interestingly, this potent combination failed where MYC and IRF4 expression was maintained by high levels of the AP-1 factor BATF. Our results identify an effective drug combination and a previously unrecognized mechanism of IMiD resistance. Significance: These results highlight the dependence of MM on IKZF1-bound super-enhancers, which can be effectively targeted by a potent therapeutic combination pairing IMiD-mediated degradation of IKZF1 and IKZF3 with EP300 inhibition. They also identify AP-1 factors as an unrecognized mechanism of IMiD resistance in MM. See related article by Neri, Barwick, et al., p. 56. See related commentary by Yun and Cleveland, p. 5. This article is featured in Selected Articles from This Issue, p. 4

Background. When a partial liver graft is unable to meet the demands of the recipient, a clinical phenomenon, small-for-size syndrome (SFSS), may ensue. Clear definition, diagnosis, and management are needed to optimize transplant outcomes. Methods. A Consensus Scientific committee (106 members from 21 countries) performed an extensive literature review on specific aspects of SFSS, recommendations underwent blinded review by an independent panel, and discussion/voting on the recommendations occurred at the Consensus Conference. Results. The ideal graft-to-recipient weight ratio of ≥0.8% (or graft volume standard liver volume ratio of ≥40%) is recommended. It is also recommended to measure portal pressure or portal blood flow during living donor liver transplantation and maintain a postreperfusion portal pressure of <15 mm Hg and/or portal blood flow of <250 mL/min/100 g graft weight to optimize outcomes. The typical time point to diagnose SFSS is the postoperative day 7 to facilitate treatment and intervention. An objective 3-grade stratification of severity for protocolized management of SFSS is proposed. Conclusions. The proposed grading system based on clinical and biochemical factors will help clinicians in the early identification of patients at risk of developing SFSS and institute timely therapeutic measures. The validity of this newly created grading system should be evaluated in future prospective studies.

Abstract Microglia-mediated neuroinflammation contributes to acute demyelination in neuromyelitis optica spectrum disorders (NMOSD). Soluble triggering receptor expressed on myeloid cells 2 (sTREM2) in the CSF has been associated with microglial activation in several neurodegenerative diseases. However, the basis for this immune-mediated attack and the pathophysiological role of sTREM2 in NMOSD remain to be elucidated. Here, we performed Mendelian randomization analysis and identified a genetic association between increased CSF sTREM2 and NMOSD risk. CSF sTREM2 was elevated in patients with NMOSD and was positively correlated with neural injury and other neuroinflammation markers. Single-cell RNA sequencing of human macrophage/microglia-like cells in CSF, a proxy for microglia, showed that increased CSF sTREM2 was positively associated with microglial dysfunction in patients with NMOSD. Furthermore, we demonstrated that sTREM2 is a reliable biomarker of microglial activation in a mouse model of NMOSD. Using unbiased transcriptomic and lipidomic screens, we identified that excessive activation, overwhelmed phagocytosis of myelin debris, suppressed lipid metabolism and enhanced glycolysis underlie sTREM2-mediated microglial dysfunction, possibly through the nuclear factor kappa B (NF-κB) signalling pathway. These molecular and cellular findings provide a mechanistic explanation for the genetic association between CSF sTREM2 and NMOSD risk and indicate that sTREM2 could be a potential biomarker of NMOSD progression and a therapeutic target for microglia-mediated neuroinflammation.

Abstract BACKGROUND Few methods exist via which to assess treatment response with high fidelity in gliomas. Cell-free DNA (cfDNA) is of growing interest as a liquid biomarker in plasma and CSF and has been used in other cancer types to optimize therapeutic regimens for individual patients. While CSF has previously been used as a source of cfDNA for gliomas, it remains unknown how cfDNA abundance and sequencing change throughout treatment and inevitable recurrence. To that end, we leveraged our growing biobank of longitudinal CSF specimens, acquired via CSF access devices, to determine the potential utility of CSF cfDNA as a monitoring tool for treatment response in patients with gliomas. MATERIAL AND METHODS Longitudinal CSF specimens were acquired via Ommaya reservoirs (NCT04692337) or ventriculoperitoneal shunts (NCT04692324) in patients with brain tumors, including gliomas. cfDNA was extracted from 1-5 mL of CSF based on available sample volumes and quantified via Qubit. Next-Generation sequencing (PredicineCARE) or low-pass whole genome sequencing (LPWGS) was performed by Predicine, Inc based on the amount of cfDNA available. RESULTS CSF acquired prior to versus after resection demonstrated an increase in quantified cfDNA (2.97x, range: 1.58-5.26x), consistent with the impact of increased parenchymal disruption and closer contact with CSF. Thereafter, CSF cfDNA continued to decrease throughout chemoradiation and adjuvant treatment and increased at recurrence, including in patients co-enrolled in immunotherapy trials for IL-7 agonists and pembrolizumab. Interestingly, copy number burden (CNB) increased by the time of recurrence in three patients with known disease progression, and continued to decrease throughout immunotherapy treatment in one patient despite concerns of pseudoprogression. In one patient with a hypermutated glioblastoma, CSF cfDNA revealed over 59 genomic alterations, including MAP2K1, KIT, and PDGFRA, and over 100 more variants of unknown significance, each of which had been detected in sequencing of the tissue acquired at resection and subsequently decreased with chemoradiation. In another patient with a known progressing EGFR-amplified GBM, over 200 new variants were identified by the patient’s final sample and EGFR copy number increased from 2 to over 30. CONCLUSION Analysis of cfDNA over a patient’s disease course, including resection and treatment with standard-of-care and experimental therapies, may be of use for disease monitoring and treatment response. Further work is needed to evaluate these findings in a larger cohort of patients and to determine the sensitivity of changes in mutations, CNB, and cfDNA quantity for glioma disease burden.