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Introduction: New tools have been developed to distinguish the COVID‐19 diagnosis from other viral infections presenting similar symptomatology and mitigate the lack of sensitivity of molecular testing. We previously identified a specific "sandglass" aspect on the white blood cells (WBC) scattergram of COVID‐19 patients, as a highly reliable COVID‐19 screening test (sensitivity: 85.9%, specificity: 83.5% and positive predictive value: 94.3%). We then decided to validate our previous data in a multicentric study. Methods: This retrospective study involved 817 patients with flu‐like illness, among 20 centers, using the same CBC instrument (XN analyzer, SYSMEX, Japan). After training, one specialist per center independently evaluated, under the same conditions, the presence of the "sandglass" aspect of the WDF scattergram, likely representing plasmacytoid lymphocytes. Results: Overall, this approach showed sensitivity: 59.0%, specificity: 72.9% and positive predictive value: 77.7%. Sensitivity improved with subgroup analysis, including in patients with lymphopenia (65.2%), patients presenting symptoms for more than 5 days (72.3%) and in patients with ARDS (70.1%). COVID‐19 patients with larger plasmacytoid lymphocyte cluster (>15 cells) more often have severe outcomes (70% vs. 15% in the control group). Conclusion: Our findings confirm that the WBC scattergram analysis could be added to a diagnostic algorithm for screening and quickly categorizing symptomatic patients as either COVID‐19 probable or improbable, especially during COVID‐19 resurgence and overlapping with future influenza epidemics. The observed large size of the plasmacytoid lymphocytes cluster appears to be a hallmark of COVID‐19 patients and was indicative of a severe outcome. Furthers studies are ongoing to evaluate the value of the new hematological parameters in combination with WDF analysis. [ABSTRACT FROM AUTHOR]

Because one-third of patients deteriorate after their admission to the emergency department, assessing the prognosis of COVID-19 patients is of great importance. However, to date, only lymphopenia and the partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2) ratio have been reported as partly predictive of COVID-19–related further deterioration, and their association has not been evaluated. We asked whether other key biomarkers of SARS-CoV-2 immunologic defects—increase in circulating immature granulocytes, loss of monocyte HLA-DR (mHLA-DR) expression, and monocyte differentiation blockade—could also predict further COVID-19 deterioration. A series of 284 consecutive COVID-19 patients, with the sole inclusion criterion of being an adult, were prospectively enrolled at emergency department admission (day 0) of 2 different hospitals: 1 for the exploratory cohort (180 patients) and 1 for the confirmatory cohort (104 patients). Deterioration was assessed over the next 7 days. Neither increased immature granulocyte levels nor monocyte differentiation blockade predicted patient worsening. Among more than 30 clinical, biological, and radiological parameters, the value of decreased P/F ratio and lymphopenia for prediction of further COVID-19 deterioration was strongly confirmed, and the loss of mHLA-DR was the only additional independent marker. Combined together in a simple OxyLymphoMono score, the 3 variables perfectly predicted patients who did not worsen and correctly predicted worsening in 59% of cases. By highlighting lymphocyte and monocyte defects as preceding COVID-19 deterioration, these results point on early immunosuppression in COVID-19 deterioration. Combining P/F ratio, lymphopenia, and loss of mHLA-DR together in a simple and robust score could offer a pragmatic method for COVID-19 patient stratification. [ABSTRACT FROM AUTHOR]

Author(s): Lee S. Nguyen [sup.1] [sup.2], Zakaria Ait Hamou [sup.1] [sup.5], Nabil Gastli [sup.3], Nicolas Chapuis [sup.4] [sup.5], Frédéric Pène [sup.1] [sup.5] Author Affiliations: (1) grid.50550.35, 0000 0001 2175 4109, [...]

Although anti‐severe acute respiratory syndrome‐coronavirus 2 antibody kinetics have been described in large populations of vaccinated individuals, we still poorly understand how they evolve during a natural infection and how this impacts viral clearance. For that purpose, we analyzed the kinetics of both viral load and neutralizing antibody levels in a prospective cohort of individuals during acute infection with alpha variant. Using a mathematical model, we show that the progressive increase in neutralizing antibodies leads to a shortening of the half‐life of both infected cells and infectious viral particles. We estimated that the neutralizing activity reached 90% of its maximal level within 11 days after symptom onset and could reduce the half‐life of both infected cells and circulating virus by a 6‐fold factor, thus playing a key role to achieve rapid viral clearance. Using this model, we conducted a simulation study to predict in a more general context the protection conferred by pre‐existing neutralization titers, due to either vaccination or prior infection. We predicted that a neutralizing activity, as measured by 50% effective dose > 103, could reduce by 46% the risk of having viral load detectable by standard polymerase chain reaction assays and by 98% the risk of having viral load above the threshold of infectiousness. Our model shows that neutralizing activity could be used to define correlates of protection against infection and transmission. [ABSTRACT FROM AUTHOR]

(1) Background: Endocan is a marker of endothelial dysfunction that may be associated with thrombotic events. The aim of the study was to investigate the performance of endocan as a marker of thrombotic events in COVID-19 patients. (2) Methods: We measured endocan in plasma from 79 documented COVID-19 patients classified according to disease severity (from mild to critical). Thrombotic events were recorded. (3) Results: Endocan concentrations at admission were significantly increased according to COVID-19 severity. Levels of endocan were significantly increased in patients experiencing thrombotic events in comparison with those without (16.2 (5.5–26.7) vs. 1.81 (0.71–10.5) ng/mL, p < 0.001). However, endocan concentrations were not different between pulmonary embolism and other thrombotic events. The Receiver Operating Characteristic (ROC) analysis for the identification of thrombotic events showed an area under the ROC curve (AUC) of 0.776 with an optimal threshold at 2.83 ng/mL (93.8% sensitivity and 54.7% specificity). When combining an endocan measurement with D-dimers, the AUC increased to 0.853. When considering both biomarkers, the Kaplan–Meier survival curves showed that the combination of endocan and D-dimers better discriminated patients with thrombotic events than those without. The combination of D-dimers and endocan was independently associated with thrombotic events. (4) Conclusions: Endocan might be a useful and informative biomarker to better identify thrombotic events in COVID-19 patients. [ABSTRACT FROM AUTHOR]

Myelodysplastic syndromes (MDS) constitute a very heterogeneous group of diseases with a high prevalence in elderly patients and a propensity for progression to acute myeloid leukemia. The complexity of these hematopoietic malignancies is revealed by the multiple recurrent somatic mutations involved in MDS pathogenesis and the paradoxical common phenotype observed in these patients characterized by ineffective hematopoiesis and cytopenia. In the context of population aging, the incidence of MDS will strongly increase in the future. Thus, precise diagnosis and evaluation of the progression risk of these diseases are imperative to adapt the treatment. Dysregulations of both innate and adaptive immune systems are frequently detected in MDS patients, and their critical role in MDS pathogenesis is now commonly accepted. However, different immune dysregulations and/or dysfunctions can be dynamically observed during the course of the disease. Monitoring the immune system therefore represents a new attractive tool for a more precise characterization of MDS at diagnosis and for identifying patients who may benefit from immunotherapy. We review here the current knowledge of the critical role of immune dysfunctions in both MDS and MDS precursor conditions and discuss the opportunities offered by the detection of these dysregulations for patient stratification. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is presenting as a systemic disease associated with vascular inflammation and endothelial injury. Severe forms of SARS-CoV-2 infection induce acute respiratory distress syndrome (ARDS) and there is still an ongoing debate on whether COVID-19 ARDS and its perfusion defect differs from ARDS induced by other causes. Beside pro-inflammatory cytokines (such as interleukin-1 β [IL-1β] or IL-6), several main pathological phenomena have been seen because of endothelial cell (EC) dysfunction: hypercoagulation reflected by fibrin degradation products called D-dimers, micro- and macrothrombosis and pathological angiogenesis. Direct endothelial infection by SARS-CoV-2 is not likely to occur and ACE-2 expression by EC is a matter of debate. Indeed, endothelial damage reported in severely ill patients with COVID-19 could be more likely secondary to infection of neighboring cells and/or a consequence of inflammation. Endotheliopathy could give rise to hypercoagulation by alteration in the levels of different factors such as von Willebrand factor. Other than thrombotic events, pathological angiogenesis is among the recent findings. Overexpression of different proangiogenic factors such as vascular endothelial growth factor (VEGF), basic fibroblast growth factor (FGF-2) or placental growth factors (PlGF) have been found in plasma or lung biopsies of COVID-19 patients. Finally, SARS-CoV-2 infection induces an emergency myelopoiesis associated to deregulated immunity and mobilization of endothelial progenitor cells, leading to features of acquired hematological malignancies or cardiovascular disease, which are discussed in this review. Altogether, this review will try to elucidate the pathophysiology of thrombotic complications, pathological angiogenesis and EC dysfunction, allowing better insight in new targets and antithrombotic protocols to better address vascular system dysfunction. Since treating SARS-CoV-2 infection and its potential long-term effects involves targeting the vascular compartment and/or mobilization of immature immune cells, we propose to define COVID-19 and its complications as a systemic vascular acquired hemopathy. [ABSTRACT FROM AUTHOR]

Background: This study aimed to assess the diagnostic relevance of CD4/CD8 ratio in cerebrospinal fluid (CSF) for the etiological diagnosis work-up of uveitis.Methods: We consecutively included patients who were referred to our department for the diagnostic workup of intermediate and/or posterior uveitis. Etiological diagnoses were established in a blind manner regarding CD4/CD8 ratio.Results: Fifty-two patients were included. A diagnosis of ocular sarcoidosis was made in 15 (29%) patients, 21% had another determined diagnosis while 50% remained of undetermined origin. Median CD4/CD8 ratio in CSF was 4.57 (IQR 3.39-5.47) in ocular sarcoidosis, 1.74 (1.60-3.18) in uveitis due to other determined cause (P = .008), and 2.83 (2.34-3.54) in those with uveitis of undetermined origin (P = .007). CD4/CD8 ratio >3.23 was associated with a diagnosis of ocular sarcoidosis.Conclusion: Determination of CD4/CD8 ratio in CSF can be useful for diagnosis work-up since a CD4/CD8 ratio >3.23 in CSF is associated with ocular sarcoidosis. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Despite its crucial importance in numerous physiological processes, iron also causes oxidative stress and damage which can promote the growth and proliferation of leukemic cells. Iron metabolism is strictly regulated and the related therapeutic approaches to date have been to restrict iron availability to tumor cells. However, since a new form of iron-catalyzed cell death has been described, termed ferroptosis, and subsequently better understood, iron excess is thought to represent an opportunity to selectively kill leukemic cells and spare normal hematopoietic cells, based on their differential iron needs. This review summarizes the physiology of iron metabolism and its deregulation in leukemia, the known ferrotoposis pathways, and therapeutic strategies to target the altered iron metabolism in leukemia for the purposes of initiating ferroptosis in these cancer cells. [ABSTRACT FROM AUTHOR]

Paraneoplastic leukemoid reaction is a challenging differential diagnosis when it presents at the time of diagnosis of cancer. Severe hyperleukocytosis with elevation of blood neutrophils and monocytes counts can evoke myeloid hematologic malignancies. We report the case of a patient who presented with blood and bone marrow features highly suggestive of chronic myelomonocytic leukemia. The diagnosis of primary lung sarcomatoid carcinoma was performed. Surgical removal of this tumor which will always remain the priority led to full normalization of blood cell count. [ABSTRACT FROM AUTHOR]

Metabolic reprogramming is a common cancer cell phenotype as it sustains growth and proliferation. Targeting metabolic activities offers a wide range of therapeutic possibilities which are applicable to acute myeloid leukemia (AML). Indeed, in addition to the IDH1/2-mutated AML model which established the proof-of-concept for specifically targeting metabolic adaptations in AML, several recent reports have expanded the scope of such strategies in these diseases. This review highlights recent findings on metabolic deregulation in AML and summarizes their implications in leukemogenesis. [ABSTRACT FROM AUTHOR]

Summary: The diagnosis of Waldenström Macroglobulinaemia (WM)/lymphoplasmacytic lymphoma (LPL) remains one of exclusion because other B‐cell lymphoproliferative disorders (B‐LPD), such as marginal zone lymphoma (MZL), can fulfil similar criteria, including MYD88 L265P mutation. It has been suggested that expression of the myeloid marker CD13 (also termed ANPEP) is more frequent in LPL than in other B‐LPD and has also been described on normal and malignant plasma cells. Here, CD13 expression was tested in a cohort of 1037 B‐LPD patients from 3 centres by flow cytometry. The percentage of CD13‐expressing cells was found to be variable among B‐LPD but significantly higher in WM/LPL (median 31% vs. 0% in non‐WM/LPL, P < 0·001). In multivariate linear regression, CD13 expression remained significantly associated with a diagnosis of WM/LPL (P < 0·001). A cut‐off value of 2% of CD19+ cells co‐expressing CD13 yielded the best diagnostic performance for WM/LPL assertion. This was further improved by association with the presence or absence of IgM paraprotein. Finally, given that previously published transcriptomic data revealed no difference in CD13 (also termed ANPEP) mRNA between normal and pathological B‐cells, the hypothesis of some post‐transcriptional regulation must be favoured. These results suggest that testing for CD13 expression in routine flow cytometry panels could help to discriminate WM/LPL from other B‐LPD. [ABSTRACT FROM AUTHOR]

Background: In this study, we primarily sought to assess the ability of flow cytometry to predict early clinical deterioration and overall survival in patients with sepsis admitted in the ED and ICU.Methods: Patients admitted for community-acquired acute sepsis from 11 hospital centers were eligible. Early (day 7) and late (day 28) deaths were notified. Levels of CD64pos granulocytes, CD16pos monocytes, CD16dim immature granulocytes (IGs), and T and B lymphocytes were assessed by flow cytometry using an identical, cross-validated, robust, and simple consensus standardized protocol in each center.Results: Among 1,062 patients screened, 781 patients with confirmed sepsis were studied (age, 67 ± 48 years; Simplified Acute Physiology Score II, 36 ± 17; Sequential Organ Failure Assessment, 5 ± 4). Patients were divided into three groups (sepsis, severe sepsis, and septic shock) on day 0 and on day 2. On day 0, patients with sepsis exhibited increased levels of CD64pos granulocytes, CD16pos monocytes, and IGs with T-cell lymphopenia. Clinical severity was associated with higher percentages of IGs and deeper T-cell lymphopenia. IG percentages tended to be higher in patients whose clinical status worsened on day 2 (35.1 ± 35.6 vs 43.5 ± 35.2, P = .07). Increased IG percentages were also related to occurrence of new organ failures on day 2. Increased IG percentages, especially when associated with T-cell lymphopenia, were independently associated with early (P < .01) and late (P < .01) death.Conclusions: Increased circulating IGs at the acute phase of sepsis are linked to clinical worsening, especially when associated with T-cell lymphopenia. Early flow cytometry could help clinicians to target patients at high risk of clinical deterioration.Trial Registry: ClinicalTrials.gov; No.: NCT01995448; URL: www.clinicaltrials.gov. [ABSTRACT FROM AUTHOR]

The mammalian target of rapamycin (mTOR) and the phosphoinositide 3-kinase (PI3K) signaling pathways are commonly deregulated in cancers and promote cellular growth, proliferation, and survival. mTOR is part of two complexes, mTORC1 and mTORC2, with different biochemical structures and substrates specificity. PI3K/AKT activation may result from genetic hits affecting different components of the pathway, whereas the mechanisms leading to constitutive mTORC1 activation remain globally unknown. The connections between the PI3K and mTOR kinases are multiple and complex, including common substrates, negative feedback loops, or direct activation mechanisms. First-generation allosteric mTOR inhibitors (eg, rapamycin) are mainly active on mTORC1 and mostly display cytostatic anti-tumor activity. Recently, second-generation catalytic mTOR inhibitors targeting both mTOR complexes 1 and 2 have been developed. Some of them also inhibit class IA PI3K. Here, we highlight recent data generated with these new inhibitors against cancer cells and their potential as anti-cancer drugs. [ABSTRACT FROM AUTHOR]