Prothrombin Time and International Normalized Ratio as Predictors of Factor VII Coagulation Activity in Pediatric Patients.

BACKGROUND: Factor VII (FVII) deficiency is characterized by normal activated partial thromboplastin time (aPTT) and prolonged prothrombin time (PT) values. It is diagnosed by determining protein level and coagulation activity (FVII:C). FVII:C measurements are expensive and time consuming. OBJECTIVES: To analyze correlations between PT, international normalized ratio (INR), and FVII:C in pediatric patients before otolaryngology surgery and to establish alternative methods for identifying FVII deficiency. METHODS: FVII:C data were collected from 96 patients with normal aPTT and prolonged PT values during preoperative otolaryngology surgery coagulation workup between 2016 and 2020. We compared demographic and clinical parameters using Spearman correlation coefficient and receiver operating characteristic (ROC) curve analysis to determine the accuracy of PT and INR values to predict FVII deficiency. RESULTS: The median values of PT, INR and FVII:C were 13.5 seconds, 1.14, and 67.5%, respectively. In total, 65 participants (67.7%) displayed normal FVII:C compared to 31 (32.3%) with decreased FVII:C. A statistically significant negative correlation was observed between FVII:C and PT values and between FVII:C and INR. Despite statistically significant ROC of 0.653 for PT (P-value = 0.017, 95% confidence interval [95%CI] 0.529-0.776) and 0.669 for INR (P-value = 0.08, 95%CI 0.551-0.788), we were unable to determine an optimal cutoff point to predict FVII:C deficiency with high sensitivity and high specificity. CONCLUSIONS: We could not identify a PT or INR threshold to best predict clinically relevant FVII:C levels. When PT is abnormal, determining FVII:C protein levels is needed for diagnosing FVII deficiency and considering surgical prophylactic treatment.

Improved outcomes in patients with chronic lymphocytic leukaemia infected during the omicron BA.5 subvariant surge.

Patients with chronic lymphocytic leukaemia (CLL) infected with SARS-CoV-2 are at increased risk of severe COVID-19 and death. The outcomes of CLL patients with COVID-19 during the omicron subvariants and in particular with BA.5 are not fully elucidated. Here, we report the outcomes of 128 CLL patients diagnosed with COVID-19 from December 2021 through November 2022. The hospitalization and 30-day mortality rates were 26.6% (n = 34) and 4.7% (n = 6), respectively. Both hospitalizations and mortality were lower during the outbreaks of the BA.2 and BA.5 subvariants (17.2%, 0% vs. 15.2%, 0%, respectively) compared with the period dominated by the BA.1 subvariant (41.5%, 11.3%).

Spatial organization and early signaling of the B-cell receptor in CLL.

Most chronic lymphocytic leukemia (CLL) clones express B-cell receptors (BcR) of both IgM/IgD isotypes; however, 5%-10% of CLL cases express isotype-switched immunoglobulin G (IgG). The early signaling and spatial patterning of the various BcRs at steady state and after activation are still fully unresolved. Herein, we show higher expression of the BcR signalosome elements and a more robust constitutive cell-intrinsic proximal BcR signaling in CLL with unmutated IGHV expressing IgM isotype (IgM U-CLL), compared with IGHV-mutated CLL (M-CLL) expressing either IgM or IgG isotypes. IgM in U-CLL is frequently located in the membrane plane in polarized patches, occasionally in caps, and sometimes inside the cells. Among M-CLL, IgM is scattered laterally in the membrane plane in a similar pattern as seen in normal B cells, whereas IgG is dispersed around the cell membrane in smaller clusters than in IgM U-CLL. Upon BcR engagement, both IgG and IgM expressing M-CLL showed attenuated signaling and only slight spatial reorganization dynamics of BcR microclusters and internalization, compared with the extensive reorganization and internalization of the BcR in IgM expressing U-CLL. The global gene signature of IgG M-CLL was closely related to that of IgM M-CLL rather than IgM U-CLL. Overall, we report fundamental differences in the basal composition, biochemical status, and spatial organization of the BcR in the three examined immunogenetic CLL subtypes that correlate with their clinical behavior. On the basis of our findings, IgG class-switched M-CLL likely represents the same disease as IgM M-CLL rather than a different biological and/or clinical entity.

REGEN-COV antibody combination in patients with lymphoproliferative malignancies and SARS-CoV-2 infection.

Patients with lymphoproliferative diseases are at high risk for SARS-CoV-2-related complications and mortality. The role of casirivimab and imdevimab (REGEN-COV), a neutralizing antibody cocktail, to treat immunocompromised hemato-oncological patients with SARS-CoV-2 disease 2019 (Covid-19) remains unknown. Here, we present our clinical experience on the outcome of 15 hematological patients treated with REGEN-COV for SARS-CoV-2 infection. Most patients failed to respond or achieved low antibody titer after 2-3 doses of BNT162b2 mRNA vaccine. All patients experienced clinical improvement with no mortality within a median follow-up of 70 days. In conclusion, early administration of REGEN-COV to high-risk hematological patients may prevent clinical deterioration and mortality from SARS-CoV-2 infection. The effectiveness of neutralizing antibodies may vary depending on the virus variants and in particular with the omicron variant (B.1.1.529).

Association of a Third Dose of BNT162b2 Vaccine With Incidence of SARS-CoV-2 Infection Among Health Care Workers in Israel.

Importance: Administration of a BNT162b2 booster dose (Pfizer-BioNTech) to fully vaccinated individuals aged 60 years and older was significantly associated with lower risk of SARS-CoV-2 infection and severe illness. Data are lacking on the effectiveness of booster doses for younger individuals and health care workers. Objective: To estimate the association of a BNT162b2 booster dose with SARS-CoV-2 infections among health care workers who were previously vaccinated with a 2-dose series of BNT162b2. Design, Setting, and Participants: This was a prospective cohort study conducted at a tertiary medical center in Tel Aviv, Israel. The study cohort included 1928 immunocompetent health care workers who were previously vaccinated with a 2-dose series of BNT162b2, and had enrolled between August 8 and 19, 2021, with final follow-up reported through September 20, 2021. Screening for SARS-CoV-2 infection was performed every 14 days. Anti-spike protein receptor binding domain IgG titers were determined at baseline and 1 month after enrollment. Cox regression with time-dependent analysis was used to estimate hazard ratios of SARS-CoV-2 infection between booster-immunized status and 2-dose vaccinated (booster-nonimmunized) status. Exposures: Vaccination with a booster dose of BNT162b2 vaccine. Main Outcomes and Measures: The primary outcome was SARS-CoV-2 infection, as confirmed by reverse transcriptase-polymerase chain reaction. Results: Among 1928 participants, the median age was 44 years (IQR, 36-52 years) and 1381 were women (71.6%). Participants completed the 2-dose vaccination series a median of 210 days (IQR, 205-213 days) before study enrollment. A total of 1650 participants (85.6%) received the booster dose. During a median follow-up of 39 days (IQR, 35-41 days), SARS-CoV-2 infection occurred in 44 participants (incidence rate, 60.2 per 100 000 person-days); 31 (70.5%) were symptomatic. Five SARS-CoV-2 infections occurred in booster-immunized participants and 39 in booster-nonimmunized participants (incidence rate, 12.8 vs 116 per 100 000 person-days, respectively). In a time-dependent Cox regression analysis, the adjusted hazard ratio of SARS-CoV-2 infection for booster-immunized vs booster-nonimmunized participants was 0.07 (95% CI, 0.02-0.20). Conclusions and Relevance: Among health care workers at a single center in Israel who were previously vaccinated with a 2-dose series of BNT162b2, administration of a booster dose compared with not receiving one was associated with a significantly lower rate of SARS-CoV-2 infection over a median of 39 days of follow-up. Ongoing surveillance is required to assess durability of the findings.

Evolution of spike mutations following antibody treatment in two immunocompromised patients with persistent COVID-19 infection.

Immunocompromised patients have an increased risk of persistent COVID-19 disease. We report here the clinical course of two patients with hematologic malignancies hospitalized due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In both patients, viral evolution including new spike gene mutations that occurred following treatment with anti-SARS-CoV-2 antibodies preparations, including convalescent plasma and bamlanivimab. These cases demonstrate the possibility of antibody-resistant SARS-CoV-2 infections evolution in immunocompromised patients.

Proteolysis Targeting Chimeras for BTK Efficiently Inhibit B-Cell Receptor Signaling and Can Overcome Ibrutinib Resistance in CLL Cells.

Proteolysis targeting chimeras (PROTACs) are small molecules that form ternary complexes between their target and E3 ligase, resulting in ubiquitination and proteasomal degradation of the target protein. Using our own designed Bruton's tyrosine kinase (BTK) PROTAC compounds, we show herein efficient BTK degradation in chronic lymphocytic leukemia (CLL) cells. The reversible non-covalent compound (NC-1) was the most potent and therefore we focused on this PROTAC to investigate its subsequent effects on the BCR pathway. NC-1 decreased baseline BTK phosphorylation as well as activation of BTK and other signaling molecules downstream of the BCR pathway, following IgM engagement. These effects were also obtained in samples from CLL patients with clinical resistance to ibrutinib and mutations at C481. NC-1 treatment further decreased baseline CD69 surface levels, completely abrogated its upregulation following IgM activation, decreased CLL cells migration toward SDF-1 and overcame stromal anti-apoptotic protection. In conclusion, our results indicate that targeting BTK using the PROTAC strategy could be a potential novel therapeutic approach for CLL.

Efficacy of the BNT162b2 mRNA COVID-19 vaccine in patients with chronic lymphocytic leukemia.

Patients with chronic lymphocytic leukemia (CLL) have an increased risk for severe COVID-19 disease and mortality. The goal of this study was to determine the efficacy of COVID-19 vaccine in patients with CLL. We evaluated humoral immune responses to the BNT162b2 messenger RNA (mRNA) COVID-19 vaccine in patients with CLL and compared responses with those obtained in age-matched healthy control subjects. Patients received 2 vaccine doses, 21 days apart, and antibody titers were measured by using the Elecsys Anti-SARS-CoV-2 S assay after administration of the second dose. In a total of 167 patients with CLL, the antibody response rate was 39.5%. A comparison between 52 patients with CLL and 52 sex- and aged-matched healthy control subjects revealed a significantly reduced response rate among patients (52% vs 100%, respectively; adjusted odds ratio, 0.010; 95% confidence interval, 0.001-0.162; P < .001). The response rate was highest in patients who obtained clinical remission after treatment (79.2%), followed by 55.2% in treatment-naive patients and 16.0% in patients under treatment at the time of vaccination. In patients treated with either Bruton's tyrosine kinase inhibitors or venetoclax ± anti-CD20 antibody, response rates were considerably low (16.0% and 13.6%). None of the patients exposed to anti-CD20 antibodies <12 months before vaccination responded. In a multivariate analysis, the independent predictors of response were younger age, female sex, lack of currently active treatment, immunoglobulin G levels ≥550 mg/dL, and immunoglobulin M levels ≥40 mg/dL. In conclusion, antibody-mediated response to the BNT162b2 mRNA COVID-19 vaccine in patients with CLL is markedly impaired and affected by disease activity and treatment. This trial was registered at www.clinicaltrials.gov as #NCT04746092.

Characteristics and Outcomes of Patients Infected with SARS-CoV-2 in Israel: Correlation between Laboratory Findings on Admission to Emergency Department and Subsequent Respiratory Failure.

BACKGROUND: There is limited clinical information on coronavirus disease-19 (COVID-19) patients in Israel. OBJECTIVES: To describe the characteristics, outcomes, and potential associations of hospitalized COVID-19 patients in Israel. METHODS: We conducted a single-center, retrospective study of 58 consecutive laboratory-confirmed COVID-19 patients admitted to Laniado Hospital, Israel, between 14 March 2020 and 14 May 2020. Demographic, clinical, and laboratory data on admission were collected and analyzed, and the association to subsequent respiratory failure was assessed. RESULTS: Mean age of patients was 70.7 ± 16.9 years (53% males, 47% females.); 74% had at least one co-morbidity. Most patients were of Jewish Ashkenazi descent. During hospitalization 15 patients (mean age 78.18 ± 10.35 years); 80% male, 73% Sephardi descent developed respiratory failure rates of 60% occurring on average 10.6 days following intubation. Laboratory tests at admission displayed a significant increase in C-reactive protein (CRP) and creatine kinase (CK) and a decrease in absolute lymphocyte count (ALC) in patients who eventually developed respiratory failure (163.97 mg/L, 340.87 IU/L, 0.886 K/µl vs. 50.01 mg/L and 123.56 IU/L, 1.28 K/µl, respectively). Multivariate logistic analysis revealed an integrated parameter of CRP, CK, and ALC highly correlated with respiratory failure. Receiver operating characteristic curve revealed the area under the curve of CRP, CK, and ALC and the integrated parameter to be 0.910, 0.784, and 0.754, respectively. CRP was the strongest predictor to correlate with respiratory failure. CONCLUSIONS: CRP, CK, and ALC levels on admission could possibly be used to detect high-risk patients prone to develop respiratory failure.

Hemato-oncology Tourism in Israel: A Retrospective Review.

PURPOSE: Despite the significant increase in medical tourism worldwide, data on medical tourist (MT) clinical characteristics and treatment outcomes are lacking. Many MTs who choose Israel to receive medical services are individuals diagnosed with hematologic malignancies. The purpose of this study was to describe hemato-oncology MTs and to compare their disease characteristics and treatment outcomes to a control group of local (Israeli) hemato-oncology patients. MATERIALS AND METHODS: In this retrospective review, we analyzed hospital records of all hemato-oncology tourists and Israeli patients diagnosed and/or treated at the Institute of Hematology, Assuta Medical Center, between 2014 and 2016. MT and local patient demographics, clinical characteristics, and treatment outcomes were compared. MT data were also analyzed according to their commitment to treatment in Israel. RESULTS: Data on 110 MTs (median age, 51.0 years; 53.6% women) and 122 local patients (median age, 65.0 years; 41.8% women) diagnosed with non-Hodgkin lymphoma (NHL), Hodgkin lymphoma, and multiple myeloma were analyzed. The most common hematologic malignancy in both MTs and local patients was NHL (54.5% and 73.0%, respectively). Among MTs, 32.7% were fully committed to treatment in Israel, 32.7% were partially committed, and 34.6% were not committed. In 25.9% of MTs, a review of their biopsy resulted in a more definitive or different diagnosis. The percentage of patients who achieved complete response to treatment was similar among MTs and local patients. CONCLUSION: MTs often require a pathologic review of their initial diagnosis and are more likely to present with advanced stages of disease. Treatment of MTs according to the appropriate clinical parameters is expected to yield similar outcomes to those of local patients.