PEDIATRIC-TYPE FOLLICULAR LYMPHOMA - A NEW PARADIGM IN DIAGNOSIS?

Background: Recognized as an entity in the 2016 WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, Pediatric-Type Follicular Lymphoma (PTFL) is a rare nodular follicular lymphoma that affects primarily children and young adults. The clinical presentation is characterized by the sudden appearance of an isolated lymphadenopathy, with a predilection for the head and neck region, without systemic symptoms. The incidence is higher in men. It has an excellent prognosis with the excision of the affected ganglion. By definition, diagnosis is histological, immunocytochemical and molecular. There are no known risk factors or any described association with immunodeficiency or viral infections. Aims: We report two clinical cases. Methods: Case 1 - a previously healthy 18-year-old boy with an isolated, non-painful, cervical lymphadenopathy of approximately 20 mm, which was incidentally found. Case 2 - a 13-year-old boy without relevant personal history, who, after the second dose of vaccination against COVID-19, developed multiple adenomegalies that spontaneously regressed. However, one month later, a right submandibular adenomegaly appeared. It was analysed by ultrasound and was described as suspicious. In both cases, a fine-needle lymph node biopsy was performed for cytological diagnosis and material was sent for immunophenotyping by flow cytometry and molecular cytogenetics by FISH. Results: Immunophenotyping suggested a large-cell B-lymphoma with a phenotype compatible with Burkitt's Lymphoma (BL). In the cytology of both cases, the population observed was more consistent with diffuse large B cell lymphoma (DLBCL) or possibly high-grade follicular lymphoma (FL). In the FISH study, no rearrangements in the MYC, BCL2, BCL6 or IRF4 genes were detected in the samples of the two cases. The lymphadenopathies were excised with a probable diagnosis of PTFL or DLBCL. Histological examination confirmed the PTFL diagnosis. Summary/Conclusion: We did not find in the literature any reference to clear causal relationship between vaccination against COVID-19 and the onset of lymphoproliferative diseases. The cytological/immunophenotypic/molecular approach of this entity in both cases seems to define a characteristic pattern, which may eventually allow, in a first approach, to suspect this diagnosis. More extensive studies will be needed to establish the role of these methodologies in the diagnosis of this pathology.

A diminished immune response underlies age-related SARS-CoV-2 pathologies.

Morbidity and mortality in response to SARS-CoV-2 infection are significantly elevated in people of advanced age. To understand the underlying biology of this phenotype, we utilize the golden hamster model to compare how the innate and adaptive immune responses to SARS-CoV-2 infection differed between younger and older animals. We find that while both hamster cohorts showed similar virus kinetics in the lungs, the host response in older animals was dampened, with diminished tissue repair in the respiratory tract post-infection. Characterization of the adaptive immune response also revealed age-related differences, including fewer germinal center B cells in older hamsters, resulting in reduced potency of neutralizing antibodies. Moreover, older animals demonstrate elevated suppressor T cells and neutrophils in the respiratory tract, correlating with an increase in TGF-ß and IL-17 induction. Together, these data support that diminished immunity is one of the underlying causes of age-related morbidity.

LINFOMA PRIMÁRIO DE SISTEMA NERVOSO CENTRAL EM PACIENTE PEDIÁTRICO HIV POSITIVO: RELATO DE CASO

Relato: Paciente de 6 anos, HIV+, iniciou quadro com crise de ausência em jan/2021. Recebeu tratamento para encefalite com melhora clínica temporária. Evoluiu com cefaleia frontal de forma progressiva, desenvolvendo ataxia, afasia, vômitos em jato e novo episódio convulsivo após 1 mês da alta. RNM de crânio evidenciou lesão expansiva em hemisfério cerebral direito com compressão do 4° ventrículo e pequenas imagens nodulares difusas com edema cerebral. Realizou cirurgia para derivação ventricular externa e biópsia das lesões. Descartadas causas infecciosas, foi diagnosticado em mar/2021 com linfoma de células B de alto grau através de exame histopatológico. Estadiamento não evidenciou doença em outros sítios. Iniciou tratamento em mar/2021 com o protocolo NHL BFM 2012 associado a rituximabe. Após o bloco AAZ1 apresentou mucosite grau IV. Após BBZ1, evoluiu com mucosite grau III precoce, íleo paralítico, tiflite e infecção leve pelo SARS-CoV-2. RNM após 2 blocos de tratamento apresentando expressiva redução das lesões previamente identificadas. Após CCZ1 apresentou íleo paralítico e pneumonia, evoluindo com quadro de insuficiência respiratória grave e óbito. Discussão: Linfoma primário do SNC (LPSNC) é um tipo raro e agressivo de LNH, mais comum em pacientes imunodeficientes, que corresponde a 0,5–2% dos tumores primários de SNC e 0,7–0,8% de todos os linfomas. A incidência desse tipo de neoplasia na população pediátrica é desconhecida devido a raridade de casos reportados. Seu subtipo mais frequente é o linfoma difuso de grandes células B. O paciente em questão foi diagnosticado com Linfoma de células B de alto grau estádio IV, duplo expressor (myc e bcl2) através do histopatológico e imuno-histoquímica com Ki67 >95%, padrão menos comum em crianças. A co-expressão das proteínas MYC e BCL2 está associada a um pior prognóstico. Pacientes duplo-expressores têm idade média de 71 anos, apresentam pior performance-status, doença mais avançada e maior índice de proliferação Ki-67. O cenário ideal seria o rastreio de MYC, BCL2 e BCL6 em todos os pacientes com linfoma de alto grau no diagnóstico e, se positivo, a complementação por FISH para avaliação de double-hit, que já confere novas abordagens prognósticas e terapêuticas em adultos. Os principais fatores prognósticos do LPSNC são idade e performance status. O tratamento de primeira linha em crianças é baseado em quimioterapia (QT) com HD-MTX. O papel da radioterapia (RT) nesses pacientes é questionável. O estudo com maior número de casos pediátricos (29) mostrou sobrevida de 82% em 3 anos, apresentando melhores taxas que dos adultos (20–40% em 5 anos) e a maioria dos casos não fez RT. A adição do anticorpo monoclonal anti-CD20, Rituximabe, ao tratamento, foi baseada em estudos recentes realizados com crianças e adolescentes com LNH de células B maduras de alto grau. Houve remissão em 95% dos pacientes que usaram a terapia combinada (rituximabe e QT) com uma maior taxa de sobrevida livre de eventos em 3 anos quando comparado àqueles que receberam somente QT (95,1% vs. 87,3%). Devido a agressividade da doença, a intensificação do tratamento se faz necessária. O uso combinado do rituximabe com a poliquimioterapia, gera maior risco de toxicidade, principalmente mielotoxicidade. O paciente em questão teve boa resposta parcial ao tratamento, porém apresentou intercorrências graves durante os 3 períodos de aplasia pós QT, o que levou ao seu óbito.

SÍNDROME DE RICHTER: RELATO DE CASO DE TRANSFORMAÇÃO DE LLC A LCMB

A Síndrome de Richter (SR) é uma condição rara caracterizada pela transformação da leucemia linfocítica crônica (LLC) mais frequentemente em linfoma difuso de grandes células B (LDCBG);todavia, menos comumente podendo se transformar em linfoma das células do manto blastoides (LCMB). A etiologia da SR é desconhecida até o momento;ainda não foram identificadas predisposições genéticas ou uma única alteração responsável por essa transformação da LLC em LCMB. Sua incidência é rara, ocorrendo transformação de LLC em 2% a 6% dos casos, e, destes, acredita-se que ocorra em < 3% dos casos por falta de evidências na literatura. O diagnóstico é realizado pela biópsia de medula óssea, por biópsia de linfonodos alterados e pelos marcadores imunohistoquímicos. O tratamento é baseado na quimioterapia e pode-se incluir o transplante de células-tronco. Esse estudo objetiva relatar e discutir a transformação da LCC em LCMB. Visto que, apesar de sua rara incidência, possui curso agressivo e de alto grau, o diagnóstico precoce se faz necessário para melhor prognóstico do paciente. Relata-se caso de paciente masculino, 63 anos, ex-tabagista pesado, ex-etilista pesado, com diagnóstico de LLC em 2011 em tratamento. Iniciada quimioterapia com 1 ciclo de rituximab em 2017, não respondendo à terapêutica. Tentou-se terapia de resgate em 2018 com rituximab + dexametasona + ciclofosfamida, sem sucesso. Iniciado em 2019 clorambucil, com resposta por 7 ciclos. Na admissão em 2020, para acompanhamento com o serviço de hematologia em hospital geral para sequência de tratamento de LLC, paciente mostra-se refratário. À ectoscopia massa bulky em região cervical à esquerda. Exames laboratoriais mostraram anemia macrocítica, leucopenia e plaquetopenia. Exames de imagem e biópsia de medula óssea revelaram esplenomegalia, linfonodomegalia paraesofágica, retrocural, mesentérica e os seguintes marcadores bioquímicos: CD20+;PAX-5+;CD5+;ciclina+;BCL2+;Ki67+;CD43+;CD3+;SOX-11+;MUM-1+;CD23-;CD10-;BCL6-;Tdt-. Conclui-se diagnóstico de síndrome de Richter com transformação LLC para LCMB, uma rara condição potencialmente relacionada à imunossupressão provocada pela doença linfoproliferativa crônica de etiologia ainda desconhecida. A evolução do paciente à nova terapêutica, o protocolo quimioterápico R-CHOP, mostrou melhora do quadro clínico no primeiro ciclo. No ínterim até o segundo ciclo, paciente contrai SARS-CoV-2 e evolui a óbito devido à infecção.

SARS-COV-2 INDUCED REMISSION OF DIFFUSE LARGE B-CELL LYMPHOMA: A CASE REPORT

Introduction: Diffuse Large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma, which accounts for approximately 30% of all non-Hodgkin lymphoma cases. Spontaneous remission of DLBCL is exceedingly rare, with only a handful of case reports that describe the phenomenon present in the literature. Specialists are investigating similar cases to find out whether the SARS-CoV-2 infection triggered an antitumor immune response, as has been described with other infections in the context of high-grade non-Hodgkin lymphoma. We report one case of an elderly woman with EBV positive DLBCL diagnosed with PCR-positive SARS-CoV-2 pneumonia in the course of the disease and their outcomes. Case report: A 81 years-old woman, was referred to the consult ambulatory of intern medicine with progressive cervical, axillary and inguinal lymphadenopathy with local pain, fever and weight loss. The biopsy of an axillary lymph node demonstrated diffuse atypical lymphoid infiltrate. Immunohistochemistry stains showed positive CD20, CD30, Bcl-2 and MUM-1. It was negative for CD3, CD10, Bcl-6, c-Myc and CMV. The Ki-67 proliferation index was 80%. Epstein-Barr virus (EBV) stain were positive. These findings were consistent with DLBCL, EBV positive, clinical Stage IIIB and R-IPI 4 (poor prognosis and high risk). Since PET-CT was unavailable, thorax and abdomen computed tomographies were performed and revealed enlarged lymph node on pulmonary hilum, pathological lymph node enlargement in the axillary and supraclavicular chains bilaterally and peri aortocaval adenomegaly, extending along the bilateral femoral iliac vessels (larger lymph nodes of 2.5cm). She was treated with 4 cycles of R-CVP (rituximab with cyclophosphamide, vincristine and prednisone). When an interim PET-CT was performed, disease progression was revealed (Lugano score 5). Therefore, considering patient age and clinical status, treatment scheme was changed to R-mini-CHOP (rituximab with reduced doses of cyclophosphamide, doxorubicin, vincristine and prednisone), achieving partial response after 4 cycles (Lugano score 4). A month after this evaluation, she was admitted to the Emergency Department with diarrhea, fever and was diagnosed with PCR-positive SARS-CoV-2 pneumonia. After 6-days hospitalization with no significant ventilatory impairment, she was discharged. No corticosteroid or immunochemotherapy was administered. Two months later, she had no palpable lymphadenopathy and a PET/CT scan revealed widespread resolution of the lymphadenopathy and reduced metabolic uptake throughout (Lugano score 1). After a 7-months follow-up, the patient still has no clinical relapse. Discussion: The putative mechanisms of action include cross-reactivity of pathogen-specic T cells with tumour antigens and natural killer cell activation by inammatory cytokines produced in response to infection. It is important to consider that the more cases of SARS-CoV-2 infection in patients with non-Hodgkin lymphoma, the more likely it is to analyze lymphoma remissions and demonstrate the exact mechanism of pathogen-specific T cells with tumor antigens. Conclusion: Because spontaneous remission of DLBCL associated with SARS-CoV-2 infection is a new event, careful investigation of these cases is important, because the information gained may lead to new therapeutic targets or treatment strategies for future patients.

LINFOMA GÁSTRICO DOUBLE HIT: RELATO DE CASO

Introdução: O linfoma não-Hodgkin (LNH) é a neoplasia hematológica mais comum, mais frequente em homens e em países subdesenvolvidos. De acordo com estudo do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), o LNH corresponde à 80% dos linfomas, destes 50% linfoma difuso de grandes células B (LDGCB), com idade média de 59,6 anos, 33% de acometimento extranodal, 62% de doença avançada, IPI (Índice Internacional de Prognóstico) intermediário alto de 24% e alto de 19% para portadores de LDGCB. Objetivos: Relatar caso de paciente diagnosticada com LNHDGCB double hit gástrico durante investigação ambulatorial de síndrome dispéptica e sua abordagem. Materiais e métodos: Levantamento de prontuário, descrição e discussão de relato de caso clínico, por meio de uma revisão integrativa utilizando bases de dados PUBMED, MEDLINE, BVS e SCIELO. Relato de caso: Feminina, 47 anos, sem comorbidades, com queixa de epigastralgia pós-prandial há 9 meses e perda ponderal de 15 kg no período, sem outros sinais e sintomas. Há 2 meses, em investigação com gastroenterologista foi realizada EDA com biópsia de lesão gástrica associada a painel imuno-histoquímico (BCL6, CD20, CD30, MYC e Ki-67 positivos) compatíveis com LNHDGCB gástrico com alto índice proliferativo, além de tomografia de abdome total com contraste, evidenciando infiltração em lobo hepático esquerdo e hilo esplênico (estádio IV), sendo encaminhada ao serviço de hematologia há aproximadamente 15 dias. Atualmente, paciente segue em programação de quimioterapia com R-da-EPOCH após término de isolamento contactante Covid. Discussão: O linfoma double-hit (LDH) é uma neoplasia de alto grau e agressiva, que integra o subgrupo de LDGCB e se traduz na translocação do gene MYC combinada à translocação gênica adicional de BCL2, BCL3, BCL6 ou CCND1. Nesses casos, há maior tendência de infiltração de medula óssea e sistema nervoso central, além de prognóstico reservado associado ao alto índice de proliferação celular, elevação de DHL sérica, acometimento acima de 70 anos, apresentação clínica em estádio avançado e má resposta terapêutica. O diagnóstico é realizado por meio de biópsia excisional do local suspeito, estudo imuno-histoquímico, e, preferencialmente, acrescido da pesquisa FISH (hibridação in situ por Fluorescência) para MYC, BCL2 e BCL6. O estadiamento obedece a classificação Lugano, baseada no antigo sistema Ann Arbor: envolvimento de região linfonodal única (I);duas ou mais regiões linfonodais do mesmo lado do diafragma (II);regiões linfonodais em ambos lados do diafragma (III);sítio extranodal fora do sistema linfático (IV). O tratamento quimioterápico envolve ciclos de R-da-EPOCH (rituximabe, dose ajustada de etoposídeo, prednisona, doxorrubicina, ciclofosfamida e vincristina) a cada 21 dias. A Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular (ABHH) considera R-da-EPOCH o tratamento padrão-ouro, porém, durante a pandemia Covid, diante da indisponibilidade de leitos e/ou bombas de infusão portáteis para tratamento ambulatorial, orienta levar em consideração a terapia com R-CHOP, seguido de estratégias de consolidação, que incluem TCTH, a fim de não atrasar o tratamento. Conclusão: O LNHDGCB double hit pode acometer jovens, em sítio extranodal e exige abordagem diferenciada por sua agressividade e alto grau associados a prognóstico reservado. Apesar disso, com as novas terapêuticas e estadiamento clínico precoce é uma neoplasia potencialmente tratável e curável, cujo tratamento pode se beneficiar do uso de técnicas citogenéticas para pesquisa de translocações gênicas.

FIRST ADULT PULMONARY CASE OF PRIOR INFECTION OF POLYPORE MUSHROOM IRPEX LACTEUS

TYPE: Case Report TOPIC: Chest Infections INTRODUCTION: Irpex lacteus is a basidiomycete found on decaying wood. Known uses include the saccharification of wheat for ethanol production;decolorization of textile effluent wastewater;and detoxification of effluents from the debittering process of olives. Rarely found to cause a human mycosis, and ours is the first adult pulmonary case that is reported. CASE PRESENTATION: 61 yr old male with Stage 4ae B cell lymphoma and bcl6 amplification s/p RCHOP, presented with recurrent right effusions. The patient yielded 500mL of transudative effusion. No prior COVID infections and he was fully vaccinated. He worked by cutting down wood in the forests. No complaints of hemoptysis, night sweats, or weight loss. PET scan revealed anterior mediastinal calcifications, a large right effusion, and a LLL nodule. The LLL nodule was biopsied, and pathology revealed necrotizing granulomas. Bronchoscopy with EBUS did not reveal granulomas within the mediastinal lymph nodes. BAL from the LLL revealed a fungal culture positive for I. lacteus. The patient did not undergo further treatment for the positive fungal culture. Follow up PET scan did not reveal progression of his lymphoma. DISCUSSION: The two documented cases of I. lacteus were within a 9 yr old with ALL and pulmonary abscess;and a 73 yr old with sarcoidosis and fungal meningitis. Due to his clinical stability, he did not require amphotericin B, as was needed in the two prior cases. CONCLUSIONS: I.lacteus is a rare cause of a human mycosis. Further investigation would be warranted in terms of treatment, as there are so few cases. DISCLOSURE: Nothing to declare. KEYWORD: fungal

Primary Analysis of ZUMA-12: A Phase 2 Study of Axicabtagene Ciloleucel (Axi-Cel) As First-Line Therapy in Patients with High-Risk Large B-Cell Lymphoma (LBCL)

Background: High-risk LBCL is associated with poor prognosis after first-line anti-CD20 mAb-containing regimens, highlighting the need for novel treatments. Axi-cel, an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy, is approved for treatment of relapsed/refractory (R/R) LBCL after ≥2 lines of systemic therapy. Here we report the primary analysis of ZUMA-12, a Phase 2, multicenter, single-arm study of axi-cel as part of first-line therapy in patients with high-risk LBCL. Methods: Eligible adults had high-risk LBCL, defined by histology (double- or triple-hit status [MYC and BCL2 and/or BCL6 translocations] per investigator) or an IPI score ≥3, plus a positive interim PET per Lugano Classification (Deauville score [DS] 4/5) after 2 cycles of an anti-CD20 mAb and anthracycline-containing regimen. Patients underwent leukapheresis and received conditioning chemotherapy (cyclophosphamide and fludarabine) followed by a single axi-cel infusion at 2×10 6 CAR T cells/kg. Non-chemotherapy bridging could be administered before conditioning per investigator discretion. The primary endpoint was investigator-assessed complete response (CR) rate per Lugano. Secondary endpoints included objective response rate (ORR;CR + partial response), duration of response (DOR), event-free survival (EFS), progression-free survival (PFS), overall survival (OS), incidence of adverse events (AEs), and levels of CAR T cells in blood and cytokines in serum. The primary analysis occurred after all treated patients had ≥6 months of follow-up. Results: As of May 17, 2021, 42 patients were enrolled and 40 were treated with axi-cel. Median age was 61 years (range, 23-86);68% of patients were male, 63% had ECOG 1, 95% had stage III/IV disease, 48% had DS4, 53% had DS5, 25% had double- or triple-hit status per central assessment, and 78% had IPI score ≥3. A total of 37 patients had centrally confirmed double- or triple-hit histology or an IPI score ≥3 and were evaluable for response, with 15.9 months of median follow-up (range, 6.0-26.7). The CR rate was 78% (n=29;95% CI, 62-90);89% of patients had an objective response, and median time to initial response was 1 month. Among all 40 treated patients, 90% had an objective response (80% CR rate). At data cutoff, 73% of response-evaluable patients had ongoing responses. Medians for DOR, EFS, and PFS were not reached;12-month estimates were 81%, 73%, and 75%, respectively. The estimated OS at 12 months was 91%. All 40 treated patients had AEs of any grade;85% of patients had Grade ≥3 AEs, most commonly cytopenias (68%). Grade ≥3 cytokine release syndrome (CRS) and neurologic events (NEs) occurred in 3 patients (8%) and 9 patients (23%), respectively. Median times to onset of CRS and NEs were 4 days (range, 1-10) and 9 days (range, 2-44), with median durations of 6 days and 7 days, respectively. All CRS and most NEs (28/29) of any grade resolved by data cutoff (1 ongoing Grade 1 tremor);39/40 CRS events resolved by 14 days post-infusion and 19/29 NEs resolved by 21 days post-infusion. Tocilizumab was administered to 63% and 3% of patients for management of CRS or NEs, respectively;corticosteroids were administered to 35% and 33% of patients for CRS and NE management. One Grade 5 event of COVID-19 occurred (Day 350). Median peak CAR T-cell level in all treated patients was 36 cells/µL (range, 7-560), and median expansion by AUC 0-28 was 495 cells/µL × days (range, 74-4288). CAR T-cell levels peaked at a median of 8 days post-infusion (range, 8-37). Higher frequency of CCR7+CD45RA+ T cells in axi-cel product, previously associated with greater expansion of CAR T cells (Locke et al. Blood Adv. 2020), was observed in ZUMA-12, compared with the ZUMA-1 study in R/R LBCL (Neelapu et al. New Engl J Med. 2017). Conclusion: In the primary analysis of ZUMA-12, axi-cel demonstrated a high rate of rapid and complete responses in patients with high-risk LBCL, a population with high unmet need. With 15.9 months of median follow-up, responses were durable as medians for DOR, EFS, nd PFS were not yet reached and over 70% of patients remained in response at data cutoff. No new safety signals were reported with axi-cel in an earlier line. Overall, axi-cel may benefit patients exposed to fewer prior therapies, and further trials in first-line high-risk LBCL are warranted to assess axi-cel in this setting. [Formula presented] Disclosures: Neelapu: Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene, Kuur, Incyte, Precision BioSciences, Legend, Adicet Bio, Calibr, and Unum Therapeutics: Other: personal fees;Kite, a Gilead Company, Bristol Myers Squibb, Merck, Poseida, Cellectis, Celgene, Karus Therapeutics, Unum Therapeutics (Cogent Biosciences), Allogene, Precision BioSciences, Acerta and Adicet Bio: Research Funding;Takeda Pharmaceuticals and related to cell therapy: Patents & Royalties;Kite, a Gilead Company, Merck, Bristol Myers Squibb, Novartis, Celgene, Pfizer, Allogene Therapeutics, Cell Medica/Kuur, Incyte, Precision Biosciences, Legend Biotech, Adicet Bio, Calibr, Unum Therapeutics and Bluebird Bio: Honoraria. Dickinson: Janssen: Consultancy, Honoraria;Takeda: Research Funding;Novartis: Consultancy, Honoraria, Research Funding, Speakers Bureau;Amgen: Honoraria;Celgene: Research Funding;Bristol-Myers Squibb: Consultancy, Honoraria;MSD: Consultancy, Honoraria, Research Funding, Speakers Bureau;Roche: Consultancy, Honoraria, Other: travel, accommodation, expenses, Research Funding, Speakers Bureau;Gilead Sciences: Consultancy, Honoraria, Speakers Bureau. Munoz: Kite, a Gilead Company, Kyowa, Bayer, Pharmacyclics/Janssen, Seagen, Acrotech/Aurobindo, Beigene, Verastem, AstraZeneca, Celgene/BMS, Genentech/Roche.: Speakers Bureau;Bayer, Gilead/Kite Pharma, Celgene, Merck, Portola, Incyte, Genentech, Pharmacyclics, Seattle Genetics, Janssen, and Millennium: Research Funding;Pharmacyclics/Abbvie, Bayer, Kite, a Gilead Company, Pfizer, Janssen, Juno/Celgene, Bristol Myers Squibb, Kyowa Kirin, Alexion, Fosun Kite, Innovent, Seagen, BeiGene, Debiopharm, Epizyme, Karyopharm, ADC Therapeutics, Servier, and Genmab: Consultancy, Other: advisory role;Alexion, AstraZeneca Rare Disease: Other: Study investigator;Targeted Oncology, OncView, Kyowa Kirin, Physicians' Education Resource, and Seagen: Honoraria. Thieblemont: Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses;Gilead Sciences: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses;Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees;Kyte: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses;Bristol Myers Squibb/Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses;Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees;Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses, Research Funding;Incyte: Honoraria, Membership on an entity's Board of Directors or advisory committees;Abbvie: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses;Cellectis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses;Hospira: Research Funding;Bayer: Honoraria;Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: Travel, Accommodations, Expenses. Oluwole: Pfizer: Consultancy;Curio Science: Consultancy;Janssen: Consultancy;Kite, a Gilead Company: Consultancy, Research Funding. Herrera: Takeda: Consultancy;Genentech: Consultancy, Research Funding;Merck: Consultancy, Research Funding;Seagen: Consultancy, Research Fundi g;AstraZeneca: Consultancy, Research Funding;Kite, a Gilead Company: Research Funding;Gilead Sciences: Research Funding;Tubulis: Consultancy;ADC Therapeutics: Consultancy, Research Funding;Bristol Myers Squibb: Consultancy, Research Funding;Karyopharm: Consultancy. Ujjani: Loxo: Research Funding;AstraZeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding;Epizyme: Consultancy, Membership on an entity's Board of Directors or advisory committees;Janssen: Consultancy;TG Therapeutics: Honoraria;Gilead: Honoraria;ACDT: Honoraria;Kite, a Gilead Company: Honoraria;Adaptive Biotechnologies: Research Funding;Atara Bio: Consultancy;AbbVie: Consultancy, Research Funding;Pharmacyclics: Consultancy, Research Funding. Lin: Sorrento: Consultancy;Legend: Consultancy;Novartis: Consultancy;Bluebird Bio: Consultancy, Research Funding;Gamida Cell: Consultancy;Janssen: Consultancy, Research Funding;Celgene: Consultancy, Research Funding;Juno: Consultancy;Vineti: Consultancy;Takeda: Research Funding;Merck: Research Funding;Kite, a Gilead Company: Consultancy, Research Funding. Riedell: Bayer: Honoraria;Karyopharm Therapeutics: Consultancy, Honoraria;Morphosys: Research Funding;Celgene/Bristol-Myers Squibb Company: Consultancy, Honoraria, Research Funding;Verastem Oncology: Honoraria;Kite, a Gilead Company: Honoraria, Research Funding, Speakers Bureau;Novartis: Consultancy, Honoraria, Research Funding;Takeda: Consultancy;BeiGene: Consultancy;Calibr: Research Funding;Xencor: Research Funding;Tessa Therapeutics: Research Funding. Kekre: Gilead: Consultancy, Honoraria;Novartis: Consultancy, Honoraria;Celgene: Consultancy, Honoraria. Lui: Gilead Sciences: Other: stock or other ownership;Kite, a Gilead Company: Current Employment, Other: travel support. Milletti: Kite, aGilead company: Current Employment;Gilead Sciences: Other: stock or other ownership. Dong: Kite, a Gilead Company: Current Employment;Gilead Sciences: Other: stock or other ownership;GliaCure/Tufts: Consultancy, Other: advisory role, Patents & Royalties. Xu: Kite, A Gilead Company: Current Employment;Gilead Sciences: Other: stock or other ownership. Chavez: MorphoSys, Bayer, Karyopharm, Kite, a Gilead Company, Novartis, Janssen, AbbVie, TeneoBio, and Pfizer: Consultancy;ADC Therapeutics: Consultancy, Research Funding;Merk: Research Funding;AstraZeneca: Research Funding;MorphoSys, AstraZeneca, BeiGene, Genentech, Kite, a Gilead Company, and Epizyme: Speakers Bureau;BMS: Speakers Bureau.

Elevated Central Carbon Metabolism - a Hallmark for Senescent Cells in Aging Human Hematopoietic Stem Cell Compartment

Comprehensive proteomic studies of HSC derived from bone marrow of healthy human subjects (n = 59) in different age groups (range: 20 - 72 years) showed that aging HSCs are characterized not only by myeloid lineage skewing, senescence associated secretory phenotype (SASP), accumulation of reactive oxygen species (ROS), anti-apoptosis, but prominently by elevated glycolysis, glucose uptake, and accumulation of glycogen. This is caused by a subset of HSC that has become more glycolytic than others and not on a per cell basis. Subsequent comparative transcriptome studies of HSCs from human subjects >60 years versus those from <30 years have confirmed this association of elevated glycolysis with aging transcriptome signature. Provided with this background and based on glucose metabolism levels, we have developed a method to isolate human HSCs (CD34+ cells) from bone marrow into three distinct subsets with high, intermediate, and low glucose uptake (GU) capacity (GU high, GU inter, GU low). For human subjects >60 years old (n=9), the proportions of these subsets are: GU high= 5.4+3.5 %, GU inter= 66.4+22.5 %, GU low= 28.2+21.7 %. For subjects <30 years (n=5), the proportions are GU high= 1.7+1.5 %, GU inter= 66.5+36.9 %, GU low= 31.8+36.7. Single-cell RNA-sequencing (scRNA-seq) studies and gene ontology analysis of biological processes revealed that, compared to the GU inter and GU low subsets, the GU high cells showed a significantly higher expression of genes involved in myeloid development, inflammation response (AIF1, CASP2, ANXA1, ZFP36), anti-apoptosis (GSTP1, NME1, BCL2, DMNT1, BAX), cell cycle checkpoint (MCL1, CDK1, CDK4, EIF5A), histone regulation (BCL6, EGR1, KDM1A, MLLT3), b-galactosidase, and significantly lower expressions of genes involved in lymphoid development, and of MDM4, MDM2, FOXP1, SOX4, RB1. Functional studies indicated that the glycolytic enzymes were elevated in elderly HSCs, and the GU low subset corresponded to primitive and more pluripotent HSCs than the GU interand GU high subsets. Pathway analyses have then demonstrated that the GU high subset is associated with up-regulated p53 as well as JAK/STAT signaling pathways, characteristic of senescent HSCs observed in murine models. Applying Gene Set Enrichment Analysis (GSEA) algorithms, we have compared the scRNA-seq data of CD34+ cells derived from young (<30 years) versus older (>60 years) subjects, as well as the scRNA-seq data from GU high subset versus GU inter and GU lowsubsets from each individual subject (n = 6). The results are shown in Figure 1. In analogy to the comparison between old (>60 years) versus young (<30 years) HSCs (CD34+ cells), GSEA of the GU high versus GU inter and GU low subsets shows the same pattern of changes - significant upregulation of gene-set expressions for (a) inflammatory response (b) G2M checkpoint, (c) MTORC1, (d) ROS, (Fig. 1B), (e) allograft rejection;and down-regulation of gene-set expressions for (f) pluripotency, (g) androgen response, (h) UV response (Fig. 1C) as well as (i) interferon-a induction during SARS-CoV2-infection (data not shown in Fig. 1). Thus, our novel findings of elevated glycolysis coupled with significant activation of MTORC1 in the senescent cells of the HSC compartment have provided evidence for the important role of calorie restriction (CR) for healthy aging of HSCs. In numerous animal models, aging has been shown to be driven by the nutrient-sensing MTORC1 network. In animal models of aging, CR has been reported to deactivate the MTOR pathway, thus slowing aging and delaying diseases of aging. Conclusion: In a series of multi-omics studies, we have demonstrated that the GU high subset is identical to the senescent cells (SCs) in human HSC compartment. Studies in animal models have shown that SCs in murine bone marrow are responsible for driving the aging process, and elimination of this subset by inhibitors of anti-apoptotic factors is able to rejuvenate hematopoiesis in mice. Our present results have provided cellular and molecular evidence that SCs in human HSC compartment re also dependent on anti-apoptotic factors, elevated MTORC1 as well as increased glycolysis for survival. Inhibition of MTORC1 or glycolysis, either by specific inhibitors or by CR, may eliminate senescent HSCs and promote rejuvenation of human hematopoiesis. [Formula presented] Disclosures: No relevant conflicts of interest to declare.