Advances in antibacterial treatment of adults with high-risk febrile neutropenia.

BACKGROUND: High-risk febrile neutropenia (HR-FN) is a life-threatening complication in patients with haematological malignancies or receiving myelosuppressive chemotherapy. Since the last international guidelines were published over 10 years ago, there have been major advances in the understanding and management of HR-FN, including on antibiotic pharmacokinetics and discontinuation/de-escalation strategies. OBJECTIVES: Summarizing major advances in the field of antibacterial therapy in patients with HR-FN: empirical therapy, pharmacokinetics of antibiotics and antibiotic stewardship. SOURCES: Narrative review based on literature review from PubMed. We focused on studies published between 2010 and 2023 about the pharmacokinetics of antimicrobials, management of antimicrobial administration, and discontinuation/de-escalation strategies. We did not address antimicrobial prophylaxis, viral or fungal infections. CONTENT: Several high-quality publications have highlighted important modifications of antibiotic pharmacokinetics in HR-FN, with standard dosages exposing patients to underdosing. These recent clinical and population pharmacokinetics studies help improve management protocols with optimized initial dosing and infusion rules for ß-lactams, vancomycin, daptomycin and amikacin; they highlight the potential benefits of therapeutic drug monitoring. A growing body of evidence also shows that antibiotic discontinuation/de-escalation strategies are beneficial for bacterial ecology and patients' outcome. We further discuss methods and limitations for implementation of such protocols in haematology. IMPLICATIONS: We highlight recent information about the management of antibacterial therapy in HR-FN that might be considered in updated guidelines for HR-FN management.

Hematopoietic differentiation is characterized by a transient peak of entropy at a single-cell level.

BACKGROUND: Mature blood cells arise from hematopoietic stem cells in the bone marrow by a process of differentiation along one of several different lineage trajectories. This is often represented as a series of discrete steps of increasing progenitor cell commitment to a given lineage, but as for differentiation in general, whether the process is instructive or stochastic remains controversial. Here, we examine this question by analyzing single-cell transcriptomic data from human bone marrow cells, assessing cell-to-cell variability along the trajectories of hematopoietic differentiation into four different types of mature blood cells. The instructive model predicts that cells will be following the same sequence of instructions and that there will be minimal variability of gene expression between them throughout the process, while the stochastic model predicts a role for cell-to-cell variability when lineage commitments are being made. RESULTS: Applying Shannon entropy to measure cell-to-cell variability among human hematopoietic bone marrow cells at the same stage of differentiation, we observed a transient peak of gene expression variability occurring at characteristic points in all hematopoietic differentiation pathways. Strikingly, the genes whose cell-to-cell variation of expression fluctuated the most over the course of a given differentiation trajectory are pathway-specific genes, whereas genes which showed the greatest variation of mean expression are common to all pathways. Finally, we showed that the level of cell-to-cell variation is increased in the most immature compartment of hematopoiesis in myelodysplastic syndromes. CONCLUSIONS: These data suggest that human hematopoietic differentiation could be better conceptualized as a dynamical stochastic process with a transient stage of cellular indetermination, and strongly support the stochastic view of differentiation. They also highlight the need to consider the role of stochastic gene expression in complex physiological processes and pathologies such as cancers, paving the way for possible noise-based therapies through epigenetic regulation.

Azacitidine for patients with Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome (VEXAS) and myelodysplastic syndrome: data from the French VEXAS registry.

Azacitidine can be effective in myelodysplastic syndromes (MDS) associated with inflammatory/autoimmune diseases. Vacuoles, E1 Enzyme, X-linked, Autoinflammatory, Somatic syndrome (VEXAS) is a new monogenic autoinflammatory syndrome caused by somatic ubiquitin-like modifier-activating enzyme 1 (UBA1) mutation, often associated with MDS, whose treatment is difficult and not yet codified. Based on a French nationwide registry of 116 patients with VEXAS, we report the efficacy and safety of azacitidine treatment in 11 patients with VEXAS with MDS. Clinical response of VEXAS to azacitidine was achieved in five patients (46%), during 6, 8+, 12, 21, 27+ months respectively, suggesting that azacitidine can be effective in selected patients with VEXAS and associated MDS.

APR-246 induces early cell death by ferroptosis in acute myeloid leukemia.

APR-246 is a promising new therapeutic agent that targets p53 mutated proteins in myelodysplastic syndromes and in acute myeloid leukemia (AML). APR-246 reactivates the transcriptional activity of p53 mutants by facilitating their binding to DNA target sites. Recent studies in solid cancers have found that APR-246 can also induce p53-independent cell death. In this study, we demonstrate that AML cell death occurring early after APR-246 exposure is suppressed by iron chelators, lipophilic antioxidants and inhibitors of lipid peroxidation, and correlates with the accumulation of markers of lipid peroxidation, thus fulfilling the definition of ferroptosis, a recently described cell death process. The capacity of AML cells to detoxify lipid peroxides by increasing their cystine uptake to maintain major antioxidant molecule glutathione biosynthesis after exposure to APR-246 may be a key determinant of sensitivity to this compound. The association of APR-246 with induction of ferroptosis (either by pharmacological compounds, or genetic inactivation of SLC7A11 or GPX4) had a synergistic effect on the promotion of cell death, both in vivo and ex vivo.

The epigenetic regulator RINF (CXXC5) maintains SMAD7 expression in human immature erythroid cells and sustains red blood cells expansion.

The gene CXXC5, encoding a Retinoid-Inducible Nuclear Factor (RINF), is located within a region at 5q31.2 commonly deleted in myelodysplastic syndrome (MDS) and adult acute myeloid leukemia (AML). RINF may act as an epigenetic regulator and has been proposed as a tumor suppressor in hematopoietic malignancies. However, functional studies in normal hematopoiesis are lacking, and its mechanism of action is unknow. Here, we evaluated the consequences of RINF silencing on cytokineinduced erythroid differentiation of human primary CD34+ progenitors. We found that RINF is expressed in immature erythroid cells and that RINF-knockdown accelerated erythropoietin-driven maturation, leading to a significant reduction (~45%) in the number of red blood cells (RBCs), without affecting cell viability. The phenotype induced by RINF-silencing was TGFß-dependent and mediated by SMAD7, a TGFß- signaling inhibitor. RINF upregulates SMAD7 expression by direct binding to its promoter and we found a close correlation between RINF and SMAD7 mRNA levels both in CD34+ cells isolated from bone marrow of healthy donors and MDS patients with del(5q). Importantly, RINF knockdown attenuated SMAD7 expression in primary cells and ectopic SMAD7 expression was sufficient to prevent the RINF knockdowndependent erythroid phenotype. Finally, RINF silencing affects 5'-hydroxymethylation of human erythroblasts, in agreement with its recently described role as a Tet2- anchoring platform in mouse. Altogether, our data bring insight into how the epigenetic factor RINF, as a transcriptional regulator of SMAD7, may fine-tune cell sensitivity to TGFß superfamily cytokines and thus play an important role in both normal and pathological erythropoiesis.

Accuracy and safety of 101 consecutives neurosurgical procedures for newly diagnosed central nervous system lymphomas: a single-institution experience.

INTRODUCTION: Brain surgery is required to ascertain the diagnosis of central nervous system lymphoma. We assessed the diagnostic yield and safety of the surgical procedures, the predictors of postoperative morbidity, and of overall survival. METHODS: Observational single-institution retrospective cohort study (1992-2020) of 101 consecutive adult patients who underwent stereotactic biopsy, open biopsy, or resection for a newly diagnosed central nervous system lymphoma. RESULTS: The diagnostic yield was 100% despite preoperative steroid administration in 48/101 cases (47.5%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.006) was an independent predictor of a new postoperative focal neurological deficit (7/101 cases, 6.9%). A previous history of hematological malignancy (p = 0.049), age 65 years or more (p = 0.031), and new postoperative neurological deficit (p < 0.001) were independent predictors of a Karnofsky Performance Status score decrease 20 points or more postoperatively (13/101 cases, 12.9%). A previous history of hematological malignancy (p = 0.034), and preoperative Karnofsky Performance Status score less than 70 (p = 0.024) were independent predictors of postoperative hemorrhage (13/101 cases, 12.9%). A preoperative Karnofsky Performance Status score less than 70 (p = 0.019), and a previous history of hematological malignancy (p = 0.014) were independent predictors of death during hospital stay (8/101 cases, 7.9%). In the 82 immunocompetent patients harboring a primary central nervous system lymphoma, age 65 years or more (p = 0.044), and time to hematological treatment more than 21 days (p = 0.008), were independent predictors of a shorter overall survival. A dedicated hematological treatment (p < 0.001) was an independent predictor of a longer overall survival. CONCLUSION: Brain biopsy is feasible with low morbidity for central nervous system lymphomas. Postoperatively, patients should be promptly referred for hematological treatment initiation.

Pharmaceutical cancer care for haematology patients on oral anticancer drugs: Findings from an economic, clinical and organisational analysis.

OBJECTIVE: The clinical benefit of pharmaceutical cares in improving the quality-of-care outcomes is well demonstrated. Clinical pharmacy services are not systematically deployed in cancer units in the absence of economic data. The aim of this prospective, observational 1-year study was to evaluate the clinical, economic and organisational impacts of pharmaceutical care into a multidisciplinary day hospital for patients treated with oral cancer drugs. METHODS: All pharmacists' interventions (PI) were documented and their impact and the probability of adverse drug events were assessed using the clinical, economic and organisational tool. RESULTS: Among 360 admissions, an average of 1.81 PI per admission was accepted. Among 452 PI leading to a clinical benefit on the patient, 16.9% had a major impact, and 1.9% had an impact on survival. The large majority of PIs (87%) increased the quality-of-care organisation. The budget impact model showed a total cost savings and cost avoidance of €539,047 per year and a cost-benefit ratio of 7.07:1. The direct cost-benefit was €201,741, and the cost avoidance was €337,306. CONCLUSION: Multidisciplinary care and pharmaceutical care are key elements to improve cancer patients' outcomes and avoid evitable healthcare costs.

Hidden in the Eyes-Recurrence of Systemic Hemopathies Reportedly "In Remission": Six Cases and Review of Literature.

Background and Objectives: Secondary ocular localizations of hematological malignancies are blinding conditions with a poor prognosis, and often result in a delay in the diagnosis. Materials and Methods: We describe a series of rare cases of ocular involvement in six patients with hematological malignancies, reportedly in remission, who presented secondary ocular localizations, challenging to diagnose. Two patients had an acute lymphoblastic leukemia (ALL) and developed either a posterior scleritis or a pseudo-panuveitis with ciliary process infiltration. One patient had iris plasmacytoma and developed an anterior uveitis as a secondary presentation. Two patients had a current systemic diffuse large B-cell lymphoma (DLBCL) and were referred either for intermediate uveitis or for papilledema and vitritis with secondary retinitis. Finally, one patient with an acute myeloid leukemia (AML) presented a conjunctival localization of a myeloid sarcoma. We herein summarize the current knowledge of ophthalmologic manifestations of extramedullary hematopathies. Results: Inflammatory signs were associated with symptomatic infiltrative lesions well displayed in either the iris, the retina, the choroid, or the cavernous sinus, from the admission of the patients in the ophthalmological department. These findings suggest that patients with ALL, AML, systemic DLBCL, and myeloma can present with ophthalmic involvement, even after having been reported as in remission following an effective systemic treatment and/or allograft. Conclusions: Early detection of hidden recurrence in the eyes may permit effective treatment. Furthermore, oncologists and ophthalmologists should be aware of those rare ocular malignant locations when monitoring patient's progression after initial treatment, and close ophthalmologic examinations should be recommended when detecting patient's ocular symptoms after treatment.

Successful nelarabine and venetoclax treatment of a relapsed/refractory mediastinal myeloid sarcoma with clonal TCR rearrangement.

Myeloid sarcomas represent a heterogeneous group of diseases with a tumoral presentation of acute myeloid leukemia. The clinical presentation of these hematologic cancers is typically aggressive and thus rapidly fatal in the absence of treatment, which relies on intensive chemotherapy that is sometimes followed by allogeneic hematopoietic stem-cell transplant (AHSCT). However, the global treatment strategy for these lesions is currently not well established. We report the case of a patient presenting with a highly refractory mediastinal myeloid sarcoma with uncommon morphologic and phenotypic characteristics and a clonal TCR rearrangement. The patient's disease was progressive despite multiple courses of intensive chemotherapy and a combination of nelarabine and venetoclax finally led to a complete metabolic response consolidated by an AHSCT. This treatment regimen, which has never been reported before, was very well tolerated especially on the neurologic and hematologic levels. This case underlines the clinical, histologic and molecular heterogeneity of what is called myeloid sarcoma and the importance of next-generation sequencing analysis of the tumor mass with both myeloid and lymphoid panels to better classify this rare entity and identify therapeutic targets.

Molecular classification and prognosis in younger adults with acute myeloid leukemia and intermediate-risk cytogenetics treated or not by gemtuzumab ozogamycin: Final results of the GOELAMS/FILO acute myeloid leukemia 2006-intermediate-risk trial.

In this randomized phase 3 study, the FILO group tested whether the addition of 6 mg/m2 of gemtuzumab ozogamycin (GO) to standard chemotherapy could improve outcome of younger patients with de novo acute myeloid leukemia (AML) and intermediate-risk cytogenetics. GO arm was prematurely closed after 254 inclusions because of toxicity. A similar complete remission rate was observed in both arms. Neither event-free survival nor overall survival were improved by GO in younger AML patients (<60 years) ineligible for allogeneic stem-cell transplantation. (P = .086; P = .149, respectively). Using unsupervised hierarchical clustering based on mutational analysis of seven genes (NPM1, FLT3-ITD, CEBPA, DNMT3A, IDH1, IDH2, and ASXL1), six clusters of patients with significant different outcome were identified. Five clusters were based on FLT3-ITD, NPM1, and CEBPA mutations as well as epigenetic modifiers (DNMT3A, IDH1/2, ASXL1), whereas the last cluster, representing 25% of patients, had no mutation and intermediate risk. One cluster isolated FLT3-ITD mutations with higher allelic ratio and a very poor outcome. The addition of GO had no impact in these molecular clusters. Although not conclusive for GO impact in AML patients <60 years, this study provides a molecular classification that distinguishes six AML clusters influencing prognosis in younger AML patients with intermediate-risk cytogenetic.

Acute and fatal cephalosporin-induced autoimmune haemolytic anaemia.

We report the case of an 82-year old male patient admitted in our medical intensive care unit for diffuse skin lesions, 3 days after the onset of ceftriaxone for bilateral pneumonia without microbiological documentation. The patient concomitantly exhibited diffuse skin lesions compatible with livedo and neurological and haemodynamic failure. Biological analysis revealed acute haemolytic anaemia. Warming of patient, red blood-cells transfusion and high-doses corticosteroids were initiated and ceftriaxone was stopped. Despite these therapeutics, the patient exhibited multiple organ failure and died. The main suspected triggering factor of this acute and fatal haemolytic anaemia was ceftriaxone administration considering: (i) the delay between cephalosporin administration and symptoms; (ii) the worsening of livedo and acrocyanosis a few hours after meningeal ceftriaxone doses; and (iii) fatal evolution. Cephalosporin-induced autoimmune haemolytic anaemia is a rare and serious cause of livedo that should be suspected in patients exhibiting livedo and acute haemolytic anaemia within hours/days following cephalosporin administration.

Mastocytosis onset in a patient with treated hairy cell leukemia: Just a coincidence?

Mastocytosis is a mast cell disease caused by functionally defective infiltrating mast cells and CD34+ mast cell precursors. The heterogeneous group of mast cell disorders is categorized into five variants in the updated 2017 World Health Organization (WHO) classification among those systemic mastocytosis with an associated neoplasm (SM-AHN). Except for myeloid neoplasia, lymphoproliferative disorders associated to SM-AHN are more scarce. Here, we report the second case ever described of associated mastocytosis and hairy-cell disease. A 38-year-old female patient without any specific medical history was diagnosed a hairy cell leukemia and BRAFV600E mutation was found in hairy cells. Since purine-analogs were avoided to prevent prolonged myelosuppression, she was treated with vemurafenib and rituximab. Despite early discontinuation due to vemurafenib-induced agranulocytosis, a partial response was observed. Strikingly, bone marrow biopsy performed one month after vemurafenib discontinuation revealed a nodular infiltration by 30% tumoral mastocytes. Along with elevated tryptase level, KITD816V mutation on mastocytes and clinical exam, the patient was diagnosed with systemic mastocytosis with an associated hematological neoplasm (SM-AHN). No BRAFV600E mutation was found on mastocytes. The physiopathology of this association is not known and might be only a coincidence or a common genetic driver mutation enhancing mast and hairy cells.

Partial response in hairy cell leukemia with vemurafenib despite early discontinuation due to agranulocytosis.

Vemurafenib is an oral BRAF kinase inhibitor approved since 2012 for the treatment of patients with unresectable or metastatic melanoma with BRAF mutations. Vemurafenib also demonstrated efficacy for patients with hairy cell leukemia genetically characterized by BRAF mutation. Here, we report the case of a 38-year-old female patient without any previous medical history who experienced agranulocytosis associated with erythrodermia after vemurafenib initiation for the treatment of hairy cell leukemia. Agranulocytosis was confirmed with bone marrow examination. Vemurafenib was considered the most probable drug responsible for this agranulocytosis and was thus stopped. We observed a full neutrophils recovery 10 days after vemurafenib cessation without any haematopoietic growth factors. A bone marrow biopsy performed 1 month after aplasia ending showed a good partial response with less than 5% of hairy cells remaining. To our knowledge, this is the first case ever described by vemurafenib-induced agranulocytosis. Thus, physicians should be warned about this risk given the growing number of patients treated with vemurafenib.

Pairing MCL-1 inhibition with venetoclax improves therapeutic efficiency of BH3-mimetics in AML.

OBJECTIVES: Venetoclax combined with hypomethylating agents is a new therapeutic strategy frequently used for treating AML patients who are not eligible for conventional chemotherapy. However, high response rates are heterogeneous due to different mechanisms mediating resistance to venetoclax such as up-regulation of MCL-1 expression. We thus tested the anti-leukemic activity of S63845, a specific MCL-1 inhibitor. METHODS: Apoptosis induces by S63845 with or without venetoclax was evaluated in primary AML samples and in AML cell lines co-cultured or not with bone marrow (BM) mesenchymal stromal cells. Sensitivity of leukemic cells to S63845 was correlated to the expression level of BCL-2, MCL-1, and BCL-XL determined by Western Blot and mass spectrometry-based proteomics. RESULTS: We observed that even if MCL-1 expression is weak compared to BCL-2, S63845 induces apoptosis of AML cells and strongly synergizes with venetoclax. Furthermore, AML cells resistant to venetoclax are highly sensitive to S63845. Interestingly, the synergistic effect of S63845 toward venetoclax-mediated apoptosis of AML cells is still observed in a context of interaction with the BM microenvironment that intrinsically mediates resistance to BCL2 inhibition. CONCLUSION: These results are therefore of great relevance for clinicians as they provide the rational for combining BCL-2 and MCL-1 inhibition in AML.

A colonic mass revealing a disseminated crystal storing histiocytosis secondary to indolent multiple myeloma: a case report with literature review.

BACKGROUND: Crystal storing histiocytosis is a rare disorder associated with monoclonal gammopathy. In this disease, monoclonal heavy and light chains accumulate in the lysosome of macrophages, leading to histiocytic reaction in different organs. It is secondary to the presence of a small B-cell clone, responsible for monoclonal immunoglobulin production. Histological diagnosis is a challenge and differential diagnoses include fibroblastic and histiocytic neoplasm. Clinical manifestations depend on the involved organs, rarely including peritoneum or digestive tract. CASE PRESENTATION: We present a case of a 75-year-old with a medical history of colonic carcinoma. She presented with abdominal pain and inflammatory syndrome revealing a colonic mass. Hemicolectomy was performed. Initial diagnosis was fibroblastic tumour. The patient worsened, and diagnosis of a diffuse crystal storing histiocytosis was finally done. Haematological exploration found an indolent IgG-kappa multiple myeloma. The initial treatment with conventional chemotherapy did not permit an improvement of the patient condition. Immunotherapy with anti-CD38 monoclonal antibody (daratumumab) was proposed with a clinical and biological response. CONCLUSION: This case report emphasizes the histopathological challenge of histiocytic tumours which may involve digestive track. It focuses on the concept of monoclonal gammopathy of clinical significance, which can have a large spectrum of manifestations.

Impact of genotype in relapsed and refractory acute myeloid leukaemia patients treated with clofarabine and cytarabine: a retrospective study.

The treatment of relapsed/refractory (R/R) acute myeloid leukaemia (AML) remains a challenge. Among salvage chemotherapy regimens, the clofarabine and cytarabine (CLARA) combination has been widely evaluated and has a favourable safety/efficacy balance. Predictive factors of efficacy in patients with R/R AML are unclear, particularly the impact of AML-related gene mutations. We report our single-centre experience on 34 R/R AML patients treated with CLARA, with a focus on the genetic characterization of our cohort. CLARA yielded a 47% response rate among this poor-prognosis AML population, while two patients (5·8%) died due to treatment-related toxicity. The two-year progression-free survival and overall survival rates were 29·4% and 35·3%, respectively. Nine patients (26%) had long-term response with a median follow-up of 39·5 months among the responders, of whom six underwent haematopoietic stem cell transplantation. Adverse karyotype did not correlate with response or survival, and secondary AML were more frequent among responders to CLARA, suggesting that this combination may successfully salvage R/R AML patients regardless of adverse prognostic markers. We also observed that a low mutational burden and absence of splice mutations correlated with prolonged survival after CLARA, suggesting that extensive genotyping may have prognostic implications in R/R AML.

Architectural and functional heterogeneity of hematopoietic stem/progenitor cells in non-del(5q) myelodysplastic syndromes.

Myelodysplastic syndromes (MDSs) are hematopoietic stem cell disorders in which recurrent mutations define clonal hematopoiesis. The origin of the phenotypic diversity of non-del(5q) MDS remains unclear. Here, we investigated the clonal architecture of the CD34+CD38- hematopoietic stem/progenitor cell (HSPC) compartment and interrogated dominant clones for MDS-initiating cells. We found that clones mainly accumulate mutations in a linear succession with retention of a dominant subclone. The clone detected in the long-term culture-initiating cell compartment that reconstitutes short-term human hematopoiesis in xenotransplantation models is usually the dominant clone, which gives rise to the myeloid and to a lesser extent to the lymphoid lineage. The pattern of mutations may differ between common myeloid progenitors (CMPs), granulomonocytic progenitors (GMPs), and megakaryocytic-erythroid progenitors (MEPs). Rare STAG2 mutations can amplify at the level of GMPs, from which it may drive the transformation to acute myeloid leukemia. We report that major truncating BCOR gene mutation affecting HSPC and CMP was beneath the threshold of detection in GMP or MEP. Consistently, BCOR knock-down (KD) in normal CD34+ progenitors modifies their granulocytic and erythroid differentiation. Clonal architecture of the HSPC compartment and mutations selected during differentiation contribute to the phenotypic heterogeneity of MDS. Defining the hierarchy of driver mutations provides insights into the process of transformation and may guide the search for novel therapeutic strategies.

Aplastic anemia in the elderly: a nationwide survey on behalf of the French Reference Center for Aplastic Anemia.

Aplastic anemia is a rare but potentially life-threatening disease that may affect older patients. Data regarding the treatment of aplastic anemia in this ageing population remains scarce. We conducted a retrospective nationwide multicenter study in France to examine current treatments for aplastic anemia patients over 60 years old. Our aims were to evaluate efficacy and tolerance, and to analyze predictive factors for response and survival. Over the course of a decade, 88 patients (median age 68.5 years) were identified in 19 centers, with a median follow up of 2.7 years; 21% had very severe and 36% severe aplastic anemia. We analyzed 184 treatment lines, mostly involving the standard combination of anti-thymocyte globulin and cyclosporine-A (33%), which was also the most frequent first-line treatment (50%). After first-line therapy, 32% of patients achieved a complete response, and 15% a partial response. Responses were significantly better in first line and in patients with good performance status, as well as in those that had followed an anti-thymocyte globulin and cyclosporine-A regimen (overall response rate of 70% after first-line treatment). All treatments were well tolerated by patients, including over the age of 70. Three-year survival was 74.7% (median 7.36 years). Age, Charlson comorbidity index and very severe aplastic anemia were independently associated with mortality. Age, per se, is not a limiting factor to aplastic anemia treatment with anti-thymocyte globulin and cyclosporine-A; this regimen should be used as a first-line treatment in elderly patients if they have a good performance status and low comorbidity index score.