Humoral serological response to the BNT162b2 vaccine is abrogated in lymphoma patients within the first 12 months following treatment with anti-CD2O antibodies.

Patients with lymphoma, especially those treated with anti-CD20 monoclonal antibodies, suffer high COVID-19-associated morbidity and mortality. The goal of this study was to assess the ability of lymphoma patients to generate a sufficient humoral response after two injections of BNT162b2 Pfizer vaccine and to identify factors influencing the response. Antibody titers were measured with the SARS-CoV-2 IgG II Quant (Abbott ) assay in blood samples drawn from lymphoma patients 4 2 weeks after the second dose of vaccine. The cutoff for a positive response was set at 50 AU/mL. Positive serological responses were observed in 51% of the 162 patients enrolled in this cross-sectional study. In a multivariate analysis, an interval of <12 months between the last anti-CD20 monoclonal antibody dose and the second vaccine dose (odds ratio=31.3 [95% confidence interval: 8.4-116.9], P<0.001) and presence of active lymphoma (odds ratio=4.2 (95% confidence interval: 2.1- 8.2), P=0.006) were identified as negative response predictors. The rate of seropositivity increased from 3% in patients vaccinated within 45 days after the last monoclonal antibody administration to 80% in patients vaccinated >1 year after this therapy. The latter percentage was equal to that of patients never exposed to monoclonal antibodies. In conclusion, lymphoma patients, especially those recently treated with anti- CD20 monoclonal antibodies, fail to develop sufficient humoral response to BNT162b2 vaccine. While a serological response is not the only predictor of immunity, its low level could make this population more vulnerable to COVID-19, which implies the need for a different vaccination schedule for such patients.

Venetoclax combinations induce high response rates in newly diagnosed acute myeloid leukemia patients ineligible for intensive chemotherapy in routine practice.

Combinations of the BCL-2 inhibitor, venetoclax, with either hypomethylating agents (HMA) or low dose cytarabine (LDAC), have shown promising results in clinical trials of AML patients unfit for intensive therapy. We report on the efficacy and safety of venetoclax combinations in AML patients treated outside of clinical trials. Complete remission (CR) + CR with incomplete count recovery (CRi) were achieved in 61% of patients, with similar CR+CRi rates in with secondary AML, and in patients who were previously treated with HMA (61% and 43%, respectively). Relapse occurred in 25% of patients, with a median event-free survival (EFS) of 11.7 months (95% CI, 10.09-13.35) in responding patients. At a median follow up of 8.7 months, the median overall survival (OS) was 9.8 months (95% CI 6.42-13.3) in the entire cohort. In multivariate analysis adverse karyotype was the only negative predictor of CR/CRi (p = .03), while both ECOG performance status (PS) and adverse karyotype were significantly associated with shorter OS (p = .023 and .038, respectively). Median OS was higher in patients achieving CR/CRi and in patients proceeding to allogeneic stem cell transplantation (allo-SCT). Treatment was well tolerated, with side effects similar to those described in the randomized clinical trials. Tumor lysis syndrome (TLS) occurred in 12% of patients. Our data support the efficacy and safety of venetoclax combinations in newly diagnosed AML patients not eligible for intensive therapy. According to our data, secondary AML patients could benefit from venetoclax combinations similarly to de-novo AML patients, and allo-SCT could be offered to selected patients achieving CR/CRi.

Neutrophil Extracellular Traps Are Increased in Chronic Myeloid Leukemia and Are Differentially Affected by Tyrosine Kinase Inhibitors.

Cardiovascular complications are increasingly reported with the use of certain tyrosine kinase inhibitors (TKIs) to treat chronic myeloid leukemia (CML). We studied neutrophil extracellular trap (NET) formation in CML and evaluated the effect of TKIs on NET formation. Neutrophils isolated from treatment-naïve patients with CML showed a significant increase in NET formation compared to matched controls at baseline and after stimulation with ionomycin (IO) and phorbol 12-myristate 13-acetate (PMA). Expression of citrullinated histone H3 (H3cit), peptidyl arginine deiminase 4 (PAD4) and reactive oxygen species (ROS) was significantly higher in CML samples compared to controls. Pre-treatment of neutrophils with TKIs was associated with a differential effect on NET formation, and ponatinib significantly augmented NET-associated elastase and ROS levels as compared to controls and other TKIs. BCR-ABL1 retroviral transduced HoxB8-immortalized mouse hematopoietic progenitors, which differentiate into neutrophils in-vitro, demonstrated increased H3cit & myeloperoxidase (MPO) expression consistent with excess NET formation. This was inhibited by Cl-amidine, a PAD4 inhibitor, but not by the NADPH inhibitor diphenyleneiodonium (DPI). Ponatinib pre-exposure significantly increased H3cit expression in HoxB8-BCR-ABL1 cells after stimulation with IO. In summary, CML is associated with increased NET formation, which is augmented by ponatinib, suggesting a possible role for NETs in promoting vascular toxicity in CML.

Cytokine Release Ensuing Interaction Between Human Peripheral Blood Mononuclears and Epstein-Barr Virus Transformed B-CLL Cell Line.

Introduction: B-cell chronic lymphocytic leukemia (B-CLL) is a common form of leukemia affecting mostly elderly individuals. The course of the disease is usually unremarkable, but because it may proceed with impaired immune defense, B-CLL might be complicated with infections and even death. The leukemic microenvironment containing a number of immune cells, mainly lymphocytes and macrophages capable to produce various molecules including inflammatory cytokines, plays an important role in the development and outcome of the disease. We studied the capacity of Epstein-Barr virus (EBV)-transformed B-cell chronic lymphocytic leukemia (B-CLL) cell line (EHEB) cells, an EBV-transformed line established from a B-CLL patient, to affect the production of inflammatory cytokines by human peripheral blood mononuclear cells (PBMC). Methods: PBMC isolated from peripheral blood of healthy donors were incubated either with EHEB cells or with their supernatants and the production of the following cytokines: tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, interferon (IFN)-γ, IL-1ra, and IL-10 were detected using the enzyme-linked immunosorbent assay method. Results: Direct contact of PBMC incubated with EHEB cells induced a marked increase of TNFα, IL-1ß, IL-6, IFNγ, and IL-10 release by the immune cells. Yet, incubation of PBMC with EHEB cells' supernatant resulted in a mild production of the same cytokines. Conclusions: The noticeable increased production of inflammatory cytokines by PBMC following direct contact with EHEB cells and to a lesser degree with their supernatants implies the existence of an immune dialogue between these two types of cells. The results support the concept that not only leukemic cells, but also peripheral blood mononuclears could serve as a therapeutic target for B-CLL.

Yield of workup for patients with idiopathic presentation of the syndrome of inappropriate antidiuretic hormone secretion.

PURPOSE: To determine the proportion of patients for whom the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the presenting symptom of an underlying disorder, to describe the yield of different diagnostic modalities for patients with SIADH and an unknown etiology, and to define patients for whom such a workup is indicated. METHODS: A single center retrospective study including all patients diagnosed with SIADH without an apparent etiology in a large community hospital and tertiary center between 1.1.07 and 1.1.13. Two physicians reviewed every patient's medical file for predetermined relevant clinical data. RESULTS: Eleven of the 99 patients without an apparent etiology for SIADH at presentation were found to have an underlying cause on workup. Yield of performed workup was low, with a pathology demonstrated on 0%-30.8% of tests according to the different modalities used. Patients with presumed idiopathic SIADH at presentation who were later found to have a specific etiology were younger than patients with true idiopathic SIADH, had a significantly shorter duration of hyponatremia prior to SIADH diagnosis, had higher urine osmolality and a clinical presentation suggestive of an undiagnosed disorder. CONCLUSIONS: Our findings support a clinically-based approach to patients with idiopathic SIADH, rather than an extensive routine workup for all patients.

The syndrome of inappropriate antidiuretic hormone secretion: Distribution and characterization according to etiologies.

PURPOSE: To determine the distribution of etiologies for the syndrome of inappropriate antidiuretic hormone secretion (SIADH) in hospitalized patients and to characterize patients according to the different etiologies. METHODS: A single-center retrospective study including all patients diagnosed with SIADH in a large community hospital and tertiary center between 1.1.2007 and 1.1.2013. Two physicians reviewed every patient's medical file for predetermined relevant clinical data. RESULTS: The study cohort included 555 patients. The most common etiologies were malignancies and medication-induced SIADH, followed by idiopathic SIADH, pulmonary infections, pain and nausea, and central nervous system (CNS) disorders. Subgroup analysis according to etiology showed that CNS disorders were associated with more severe episodes of SIADH. Patients with idiopathic SIADH were older than patients with a specific diagnosis, had a lower urine osmolality, and required less treatment with hypertonic saline. Long-term survival was determined primarily by SIADH etiology rather than hyponatremia severity, with hazard ratios for death of up to 7.31 (95% CI 4.93-10.82, p<0.001) for patients with malignancy-associated SIADH as compared to patients with idiopathic SIADH. Hyponatremia grade at short-term follow-up was also predictive for long-term survival (HR 1.42 per grade, 95% CI 1.21-1.66, p<0.001). CONCLUSIONS: Patients with SIADH have different characteristics and a different prognosis according to SIADH etiology. Serum sodium concentration at short-term follow-up is predictive of long-term survival. These findings might have diagnostic and treatment-related implications.