Normal B cells express ZAP70 in chronic lymphocytic leukemia: A link between autoimmunity and lymphoproliferation?

ZAP70 has a prognostic value in chronic lymphocytic leukemia (CLL), through altered B-cell receptor signaling, which is important in CLL pathogenesis. A good correlation between ZAP70 expression in CLL cells and the occurrence of autoimmune phenomena has been reported. Yet, the great majority of CLL-associated autoimmune cytopenia is due to polyclonal immunoglobulin (Ig) G synthesized by nonmalignant B cells, and this phenomenon is poorly understood. Here, we show, using flow cytometry, that a substantial percentage of CD5- nonmalignant B cells from CLL patients expresses ZAP70 compared with CD5- B cells from healthy subjects. This ZAP70 expression in normal B cells from CLL patients was also evidenced by the detection of ZAP70 mRNA at single-cell level with polyclonal Ig heavy- and light-chain gene transcripts. ZAP70+ normal B cells belong to various B-cell subsets and their presence in the naïve B-cell subset suggests that ZAP70 expression may occur during early B-cell development in CLL patients and potentially before malignant transformation. The presence of ZAP70+ normal B cells is associated with autoimmune cytopenia in CLL patients in our cohort of patients, and recombinant antibodies produced from these ZAP70+ nonmalignant B cells were frequently autoreactive including anti-platelet reactivity. These results provide a better understanding of the implication of ZAP70 in CLL leukemogenesis and the mechanisms of autoimmune complications of CLL.

Challenges for quality and utilization of real-world data for diffuse large B-cell lymphoma in REALYSA, a LYSA cohort.

ABSTRACT: Real-world data (RWD) are essential to complement clinical trial (CT) data, but major challenges remain, such as data quality. REal world dAta in LYmphoma and Survival in Adults (REALYSA) is a prospective noninterventional multicentric cohort started in 2018 that included patients newly diagnosed with lymphoma in France. Herein is a proof-of-concept analysis on patients with first-line diffuse large B-cell lymphoma (DLBCL) to (1) evaluate the capacity of the cohort to provide robust data through a multistep validation process; (2) assess the consistency of the results; and (3) conduct an exploratory transportability assessment of 2 recent phase 3 CTs (POLARIX and SENIOR). The analysis population comprised 645 patients with DLBCL included before 31 March 2021 who received immunochemotherapy and for whom 3589 queries were generated, resulting in high data completeness (<4% missing data). Median age was 66 years, with mostly advanced-stage disease and high international prognostic index (IPI) score. Treatments were mostly rituximab, cyclophosphamide, doxorubicin hydrochloride, vincristine, and prednisone (R-CHOP 75%) and reduced dose R-CHOP (13%). Estimated 1-year event-free survival (EFS) and overall survival rates were 77.9% and 90.0%, respectively (median follow-up, 9.9 months). Regarding transportability, when applying the CT's main inclusion criteria (age, performance status, and IPI), outcomes seemed comparable between patients in REALYSA and standard arms of POLARIX (1-year progression-free survival 79.8% vs 79.8%) and SENIOR (1-year EFS, 64.5% vs 60.0%). With its rigorous data validation process, REALYSA provides high-quality RWD, thus constituting a platform for numerous scientific purposes. The REALYSA study was registered at www.clinicaltrials.gov as #NCT03869619.

Stem Cell Responsiveness to Imatinib in Chronic Myeloid Leukemia.

Chronic myeloid leukemia (CML) is a clonal myeloproliferative disease characterized by the presence of the BCR-ABL fusion gene, which results from the Philadelphia chromosome. Since the introduction of tyrosine kinase inhibitors (TKI) such as imatinib mesylate (IM), the clinical outcomes for patients with CML have improved significantly. However, IM resistance remains the major clinical challenge for many patients, underlining the need to develop new drugs for the treatment of CML. The basis of CML cell resistance to this drug is unclear, but the appearance of additional genetic alterations in leukemic stem cells (LSCs) is the most common cause of patient relapse. However, several groups have identified a rare subpopulation of CD34+ stem cells in adult patients that is present mainly in the bone marrow and is more immature and pluripotent; these cells are also known as very small embryonic-like stem cells (VSELs). The uncontrolled proliferation and a compromised differentiation possibly initiate their transformation to leukemic VSELs (LVSELs). Their nature and possible involvement in carcinogenesis suggest that they cannot be completely eradicated with IM treatment. In this study, we demonstrated that cells from CML patients with the VSELs phenotype (LVSELs) similarly harbor the fusion protein BCR-ABL and are less sensitive to apoptosis than leukemic HSCs after IM treatment. Thus, IM induces apoptosis and reduces the proliferation and mRNA expression of Ki67 more efficiently in LHSCs than in leukemic LVSELs. Finally, we found that the expression levels of some miRNAs are affected in LVSELs. In addition to the tumor suppressor miR-451, both miR-126 and miR-21, known to be responsible for LSC leukemia-initiating capacity, quiescence, and growth, appear to be involved in IM insensitivity of LVSELs CML cell population. Targeting IM-resistant CML leukemic stem cells by acting via the miRNA pathways may represent a promising therapeutic option.

Deciphering the Cardiovascular Potential of Human CD34+ Stem Cells.

Ex vivo monitored human CD34+ stem cells (SCs) injected into myocardium scar tissue have shown real benefits for the recovery of patients with myocardial infarctions. They have been used previously in clinical trials with hopeful results and are expected to be promising for cardiac regenerative medicine following severe acute myocardial infarctions. However, some debates on their potential efficacy in cardiac regenerative therapies remain to be clarified. To elucidate the levels of CD34+ SC implication and contribution in cardiac regeneration, better identification of the main regulators, pathways, and genes involved in their potential cardiovascular differentiation and paracrine secretion needs to be determined. We first developed a protocol thought to commit human CD34+ SCs purified from cord blood toward an early cardiovascular lineage. Then, by using a microarray-based approach, we followed their gene expression during differentiation. We compared the transcriptome of undifferentiated CD34+ cells to those induced at two stages of differentiation (i.e., day three and day fourteen), with human cardiomyocyte progenitor cells (CMPCs), as well as cardiomyocytes as controls. Interestingly, in the treated cells, we observed an increase in the expressions of the main regulators usually present in cardiovascular cells. We identified cell surface markers of the cardiac mesoderm, such as kinase insert domain receptor (KDR) and the cardiogenic surface receptor Frizzled 4 (FZD4), induced in the differentiated cells in comparison to undifferentiated CD34+ cells. The Wnt and TGF-ß pathways appeared to be involved in this activation. This study underlined the real capacity of effectively stimulated CD34+ SCs to express cardiac markers and, once induced, allowed the identification of markers that are known to be involved in vascular and early cardiogenesis, demonstrating their potential priming towards cardiovascular cells. These findings could complement their paracrine positive effects known in cell therapy for heart disease and may help improve the efficacy and safety of using ex vivo expanded CD34+ SCs.

Hairy cell leukemia: a specific 17-gene expression signature points to new targets for therapy.

BACKGROUND: Hairy cell leukemia (HCL) is a rare chronic B cell malignancy, characterized by infiltration of bone marrow, blood and spleen by typical "hairy cells" that bear the BRAFV600E mutation. However, in addition to the intrinsic activation of the MAP kinase pathway as a consequence of the BRAFV600E mutation, the potential participation of other signaling pathways to the pathophysiology of the disease remains unclear as the precise origin of the malignant hairy B cells. MATERIALS AND METHODS: Using mRNA gene expression profiling based on the Nanostring technology and the analysis of 290 genes with crucial roles in B cell lymphomas, we defined a 17 gene expression signature specific for HCL. RESULTS: Separate analysis of samples from classical and variant forms of hairy cell leukemia showed almost similar mRNA expression profiles apart from overexpression in vHCL of the immune checkpoints CD274 and PDCD1LG2 and underexpression of FAS. Our results point to a post-germinal memory B cell origin and in some samples to the activation of the non-canonical NF-κB pathway. CONCLUSIONS: This study provides a better understanding of the pathogenesis of HCL and describes new and potential targets for treatment approaches and guidance for studies in the molecular mechanisms of HCL.

Acquired Thrombotic Thrombocytopenic Purpura After BNT162b2 COVID-19 Vaccine: Case Report and Literature Review.

Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy that is deadly if not treated promptly. The treatment of choice in patients presenting with TTP is plasma exchanges. However, immunosuppressive therapy and caplacizumab have significantly improved outcomes in TTP. This microangiopathy is classically divided into 2 entities: hereditary and acquired TTP (aTTP), caused by an autoantibody against ADAMTS 13. We present a case study of a patient wth TTP occurring after a second dose of the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine along with a review of the literature. A 55-year-old patient presented with gastrointestinal symptoms, anemia, and severe thrombocytopenia. The blood film revealed the presence of schistocytes. A diagnosis of aTTP was established because the patient had severe ADAMTS 13 deficiency and autoantibodies against ADAMTS 13 were positive. This episode occurred 10 days after the patient received the COVID-19 vaccine. The patient received plasma exchanges, prednisone, rituximab, and caplacizumab and achieved complete remission. Ten patients with aTTP induced by the COVID-19 vaccine have been reported in the literature. Most of these situations occurred after the second dose of COVID-19 vaccine, and 7 patients were noted to have received the BNT162b2 vaccine. Caplacizumab was used in 6 patients, and complete remission was achieved in 8 patients.

Disentangling molecular and clinical stratification patterns in beta-galactosidase deficiency.

INTRODUCTION: This study aims to define the phenotypic and molecular spectrum of the two clinical forms of ß-galactosidase (ß-GAL) deficiency, GM1-gangliosidosis and mucopolysaccharidosis IVB (Morquio disease type B, MPSIVB). METHODS: Clinical and genetic data of 52 probands, 47 patients with GM1-gangliosidosis and 5 patients with MPSIVB were analysed. RESULTS: The clinical presentations in patients with GM1-gangliosidosis are consistent with a phenotypic continuum ranging from a severe antenatal form with hydrops fetalis to an adult form with an extrapyramidal syndrome. Molecular studies evidenced 47 variants located throughout the sequence of the GLB1 gene, in all exons except 7, 11 and 12. Eighteen novel variants (15 substitutions and 3 deletions) were identified. Several variants were linked specifically to early-onset GM1-gangliosidosis, late-onset GM1-gangliosidosis or MPSIVB phenotypes. This integrative molecular and clinical stratification suggests a variant-driven patient assignment to a given clinical and severity group. CONCLUSION: This study reports one of the largest series of b-GAL deficiency with an integrative patient stratification combining molecular and clinical features. This work contributes to expand the community knowledge regarding the molecular and clinical landscapes of b-GAL deficiency for a better patient management.

Identification of driver genes for critical forms of COVID-19 in a deeply phenotyped young patient cohort.

The drivers of critical coronavirus disease 2019 (COVID-19) remain unknown. Given major confounding factors such as age and comorbidities, true mediators of this condition have remained elusive. We used a multi-omics analysis combined with artificial intelligence in a young patient cohort where major comorbidities were excluded at the onset. The cohort included 47 "critical" (in the intensive care unit under mechanical ventilation) and 25 "non-critical" (in a non-critical care ward) patients with COVID-19 and 22 healthy individuals. The analyses included whole-genome sequencing, whole-blood RNA sequencing, plasma and blood mononuclear cell proteomics, cytokine profiling, and high-throughput immunophenotyping. An ensemble of machine learning, deep learning, quantum annealing, and structural causal modeling were used. Patients with critical COVID-19 were characterized by exacerbated inflammation, perturbed lymphoid and myeloid compartments, increased coagulation, and viral cell biology. Among differentially expressed genes, we observed up-regulation of the metalloprotease ADAM9. This gene signature was validated in a second independent cohort of 81 critical and 73 recovered patients with COVID-19 and was further confirmed at the transcriptional and protein level and by proteolytic activity. Ex vivo ADAM9 inhibition decreased severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) uptake and replication in human lung epithelial cells. In conclusion, within a young, otherwise healthy, cohort of individuals with COVID-19, we provide the landscape of biological perturbations in vivo where a unique gene signature differentiated critical from non-critical patients. We further identified ADAM9 as a driver of disease severity and a candidate therapeutic target.

A simple clinical score to promote and enhance ferroportin disease screening.

BACKGROUND & AIMS: Ferroportin disease is a rare genetic iron overload disorder which may be underdiagnosed, with recent data suggesting it occurs at a higher prevalence than suspected. Costs and the lack of defined criteria to prompt genetic testing preclude large-scale molecular screening. Hence, we aimed to develop a readily available scoring system to promote and enhance ferroportin disease screening. METHODS: Our derivation cohort included probands tested for ferroportin disease from 2008 to 2016 in our rare disease network. Data were prospectively recorded. Univariate and multivariate logistic regression were used to determine significant criteria, and odds ratios were used to build a weighted score. A cut-off value was defined using a ROC curve with a predefined aim of 90% sensitivity. An independent cohort was used for cross validation. RESULTS: Our derivation cohort included 1,306 patients. Mean age was 55±14 years, ferritin 1,351±1,357 µg/L, and liver iron concentration (LIC) 166±77 µmol/g. Pathogenic variants (n = 32) were identified in 71 patients. In multivariate analysis: female sex, younger age, higher ferritin, higher LIC and the absence of hypertension or diabetes were significantly associated with the diagnosis of ferroportin disease (AUROC in whole derivation cohort 0.83 [0.78-0.88]). The weighted score was based on sex, age, the presence of hypertension or diabetes, ferritin level and LIC. An AUROC of 0.83 (0.77-0.88) was obtained in the derivation cohort without missing values. Using 9.5 as a cut-off, sensitivity was 93.6 (91.7-98.3) %, specificity 49.5 (45.5-53.6) %, positive likelihood ratio 1.8 (1.6-2.0) and negative likelihood ratio 0.17 (0.04-0.37). CONCLUSION: We describe a readily available score with simple criteria and good diagnostic performance that could be used to screen patients for ferroportin disease in routine clinical practice. LAY SUMMARY: Increased iron burden associated with metabolic syndrome is a very common condition. Ferroportin disease is a dominant genetic iron overload disorder whose prevalence is higher than initially thought. They can be difficult to distinguish from each other, but the limited availability of genetic testing and the lack of definitive guidelines prevent adequate screening. We herein describe a simple and definitive clinical score to help clinicians decide whether to perform genetic testing.

Humoral response to mRNA anti-COVID-19 vaccines BNT162b2 and mRNA-1273 in patients with chronic lymphocytic leukemia.

Immunocompromised individuals such as patients with chronic lymphocytic leukemia (CLL) are at risk of impaired immune responses to vaccination. The objective of our study was to evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody responses in patients with CLL after the first, second, and third doses of the BNT162b2 or mRNA-1273 vaccines and after a single dose for patients with confirmed previous COVID-19. In all, 530 patients were included in the study. Patients received 2 doses at a 4-week interval and a third dose if they were seronegative after the second dose. Response rate was 27% after dose 1 and 52% after dose 2. Post-dose 2 treatment-naïve patients had the highest response rate (72%) followed by patients previously treated by chemoimmunotherapy (60%). Among patients receiving therapy, those receiving Bruton tyrosine kinase inhibitor alone (22%) or in combination with anti-CD20 monoclonal antibodies or venetoclax (0%) had the poorer response rate whereas patients who received venetoclax monotherapy achieved a significantly higher response rate (52%). A multivariable analysis identified age older than 65 years, ongoing CLL treatment, and gamma globulin ≤6 g/L as independent predictors of the absence of seroconversion. Post-dose 2 seronegative patients had a global response rate of 35% after dose 3. This study provides an argument for the use of a third dose and for prophylactic SARS-CoV-2 neutralizing monoclonal antibodies.

Differential Expression of the Tetraspanin CD9 in Normal and Leukemic Stem Cells.

CD9 plays a crucial role in cellular growth, mobility, and signal transduction, as well as in hematological malignancy. In myeloid neoplasms, CD9 is involved in the altered interactions between leukemic and stromal cells. However, apart from its role in CD34+ progenitors and myeloid and megakaryocytic differentiation, its function in normal and leukemic pluripotent cells has not yet been determined. Very small embryonic-like stem cells (VSELs) are promising pluripotent stem cells found in adult tissues that can be developed for safe and efficient regenerative medicine. VSELs express different surface receptors of the highest importance in cell functioning, including CD9, and can be effectively mobilized after organ injury or in leukemic patients. In the present study, we observed that CD9 is among the most expressed receptors in VSELs under steady-state conditions; however, once the VSELs are expanded, CD9+ VSELs decrease and are more apoptotic. CD9- VSELs had no proliferative improvement in vitro compared to those that were CD9+. Interestingly, the addition of SDF-1 induced CD9 expression on the surface of VSELs, as observed by flow cytometry, and improved their migration. In addition, we observed, in the phenotypically identical VSELs present in the peripheral blood of patients with myeloproliferative neoplasms, compared to healthy subjects, a significantly higher number of CD9+ cells. However, in their hematopoietic stem cell (HSC) counterparts, the expression remained comparable. These results indicate that, likewise, in progenitors and mature cells, CD9 may play an important function in normal and malignant VSELs. This could explain the refractoriness observed by some groups of expanded stem cells to repairing efficiently damaged tissue when used as a source in cell therapies. Understanding the function of the CD9 receptor in normal and malignant CD34+ and VSELs, along with its relationship with the CXCR4/SDF-1 pathway, will enable advances in the field of adult pluripotent cell usage in regenerative medicine and in their role in leukemia.

Prolonged in-hospital stay and higher mortality after Covid-19 among patients with non-Hodgkin lymphoma treated with B-cell depleting immunotherapy.

Prolonged Covid-19 is an emerging issue for patients with lymphoma or immune deficiency. We aimed to examine prolonged length of in-hospital stay (LOS) due to Covid-19 among patients with lymphoma and assess its determinants and outcomes. Adult patients with lymphoma admitted for Covid-19 to 16 French hospitals in March and April, 2020 were included. Length of in-hospital stay was analyzed as a competitor vs death. The study included 111 patients. The median age was 65 years (range, 19-92). Ninety-four patients (85%) had B-cell non-Hodgkin lymphoma. Within the 12 months prior to hospitalization for Covid-19, 79 patients (71%) were treated for their lymphoma. Among them, 63 (57%) received an anti-CD20 therapy. Fourteen patients (12%) had relapsed/refractory disease. The median LOS was 14 days (range, 1-235). After a median follow-up of 191 days (3-260), the 6-month overall survival was 69%. In multivariable analyses, recent administration of anti-CD20 therapy was associated with prolonged LOS (subdistribution hazard ratio 2.26, 95% confidence interval 1.42-3.6, p < 0.001) and higher risk of death (hazard ratio 2.17, 95% confidence interval 1.04-4.52, p = 0.039). An age ≥ 70 years and relapsed/refractory lymphoma were also associated with prolonged LOS and decreased overall survival. In conclusion, an age ≥ 70 years, a relapsed/refractory lymphoma and recent administration of anti-CD20 therapy are risk factors for prolonged LOS and death for lymphoma patients hospitalized for Covid-19. These findings may contribute to guide the management of lymphoma during the pandemic, support evaluating specific therapeutic approaches, and raise questions on the efficacy and timing of vaccination of this particular population.

Multicentric MFI30 study: Standardization of flow cytometry analysis of CD30 expression in non-Hodgkin lymphoma.

CD30 transmembrane receptor, a member of the tumor necrosis factor receptor family, is expressed in different lymphomas. Brentuximab vedotin (BV), a CD30 monoclonal antibody (Ab)-drug conjugate, is effective in CD30-positive lymphomas. However, the response to BV is not always correlated to CD30 expression detected by immunohistochemistry (IHC). The objectives of this study were to standardize and evaluate CD30 intensity by flow cytometry (FCM) in non-Hodgkin's lymphomas. Twelve centers analyzed 161 cases on standardized cytometers using normalized median fluorescence intensity (nMFI30) of three different Abs, of which one clone can recognize the same epitope as BV. FCM distinguished four groups of cases: negative group (n = 110) which showed no expression with the three clones; high positive group (n = 13) which gave nMFI30 > 5% with all tested clones; dim positive group (n = 17) which showed nMFI30 > 1% with all tested clones and <5% for at least one; discordant group (n = 21) with positive and negative expression of the different clones. In consistency with the literature, CD30 was positive in all anaplastic large cell lymphomas, in some diffuse large B-cell lymphomas (DLBCL), and in other rare lymphomas. FCM results were concordant with those of IHC in 77% of cases. Discrepancies could be explained by clones-related differences, microenvironment, or intracytoplasmic staining. Interestingly, FCM was more sensitive than IHC in 11% of cases, especially in DLBCL. Multicenter standardized FCM of specific CD30 could improve case detection and extend the treatment of BV to various CD30-positive lymphomas.

Plasmacytoid dendritic cells proliferation associated with acute myeloid leukemia: phenotype profile and mutation landscape

Neoplasms involving plasmacytoid Dendritic Cells (pDCs) include Blastic pDC Neoplasms (BPDCN) and other pDC proliferations, where pDCs are associated with myeloid malignancies: most frequently Chronic MyeloMonocytic Leukemia (CMML) but also Acute Myeloid Leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDCs in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DCs (cDCs) associated in the same sample, by phenotypic and molecular analyses (targeted NGS, 70 genes). We compared 15 pDC-AML at diagnosis with 21 BPDCN and 11 normal pDCs from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDCs (4-36%), monocytes in 14 cases (1-10%) and cDCs (2 cases, 4.8-19%). pDCs in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56- in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a pre-pDC stage. In all cases, pDCs, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.

Prognostic value of high-sensitivity measurable residual disease assessment after front-line chemoimmunotherapy in chronic lymphocytic leukemia.

Measurable residual disease (MRD) status is widely adopted in clinical trials in patients with chronic lymphocytic leukemia (CLL). Findings from FILO group trials (CLL2007FMP, CLL2007SA, CLL2010FMP) enabled investigation of the prognostic value of high-sensitivity (0.7 × 10-5) MRD assessment using flow cytometry, in blood (N = 401) and bone marrow (N = 339), after fludarabine, cyclophosphamide, and rituximab (FCR)-based chemoimmunotherapy in a homogeneous population with long follow-up (median 49.5 months). Addition of low-level positive MRD < 0.01% to MRD ≥ 0.01% increased the proportion of cases with positive MRD in blood by 39% and in bone marrow by 27%. Compared to low-level positive MRD < 0.01%, undetectable MRD was associated with significantly longer progression-free survival (PFS) when using blood (72.2 versus 42.7 months; hazard ratio 0.40, p = 0.0003), but not when using bone marrow. Upon further stratification, positive blood MRD at any level, compared to undetectable blood MRD, was associated with shorter PFS irrespective of clinical complete or partial remission, and a lower 5-year PFS rate irrespective of IGHV-mutated or -unmutated status (all p < 0.05). In conclusion, high-sensitivity (0.0007%) MRD assessment in blood yielded additional prognostic information beyond the current standard sensitivity (0.01%). Our approach provides a model for future determination of the optimal MRD investigative strategy for any regimen.

Determinants of outcome in Covid-19 hospitalized patients with lymphoma: A retrospective multicentric cohort study.

BACKGROUND: Patients with lymphoma are immunocompromised because of the disease per se and its treatments. We aimed to describe the characteristics of patients with lymphoma hospitalized for Coronavirus Disease 2019 (Covid-19) and to analyze pre-Covid-19 determinants of mortality. METHODS: This retrospective multicentric cohort study used the Programme de Médicalisation des Systèmes d'Information database to identify all adult patients with lymphoma, hospitalized for Covid-19 in March and April 2020, in 12 hospitals of three French regions with pandemic outbreaks. The characteristics of lymphoma and Covid-19 were collected from medical charts. FINDINGS: Eighty-nine patients were included. The median age was 67 years (range, 19-92), 66% were male and 72% had a comorbidity. Most patients had B-cell non-Hodgkin lymphoma (86%) and had received a lymphoma treatment within one year (70%). With a median follow-up of 33 days from admission, 30-day overall survival was 71%, (95% confidence interval, 62-81%). In multivariable analysis, having an age ≥ 70 years (hazard ratio 2·87, 1·20-6·85, p = 0·02) and relapsed/refractory lymphoma (hazard ratio 2·54, 1·14-5·66, p = 0·02) were associated with mortality. Recent bendamustine treatment (n = 9) was also pejorative (hazard ratio 3·20, 1·33-7·72, p = 0·01), but was strongly associated with relapsed/refractory lymphoma. Remarkably, 30-day overall survival for patients < 70 years of age without relapsed/refractory lymphoma was 88% (78% - 99%). INTERPRETATION: Thirty-day mortality was associated with being older and relapsed/refractory lymphoma. Survival of patients younger than 70 years without relapsed/refractory lymphoma was comparable to that of the general population. FUNDING: There have been no specific funds to run this study.