Patients with myeloproliferative neoplasms and COVID-19 have increased rates of arterial thrombosis.

Background: Both coronavirus disease-2019 (COVID-19) and myeloproliferative neoplasms (MPNs) are associated with systemic inflammation and risk of thrombosis. Risk of thrombosis in patients with COVID with and without MPNs has not been extensively studied. Methods: Retrospective cohort study of 44 patients with MPNs and 1114 patients without MPNs positive for SARS-COV-2. Outcomes were arterial thrombosis (AT), venous thromboembolism (VTE), bleeding, and death. Time-to-event analysis was performed using competing risk regression model and Cox proportional hazards. Results: AT occurred more frequently in patients with MPN (7% vs. 1%, p = 0.03). Rates of VTE (7% vs. 5%, p = 0.73), bleeding (7% vs. 2%, p = 0.06), and death (9% vs. 6%, p = 0.32) were similar. MPN patients were older and had more cardiovascular comorbidities. After time-to-event competing-risk regression adjusting for age, MPN patients had higher risk of AT (subdivision hazards ratio 3.95, 95% CI 1.09-14.39) but not VTE, bleeding, or death. Conclusions: Among patients with COVID-19, MPN patients had higher risk of arterial thrombosis but not VTE, bleeding, and death compared with non-MPN patients. Larger studies are needed to confirm our findings given the limited sample size.

Association of Thrombosis With Hypereosinophilic Syndrome in Patients With Genetic Alterations.

Importance: Hypereosinophilic syndromes (HESs) are a rare group of disorders that result in overproduction of eosinophils, leading to tissue damage. Thrombotic complications in HES and associated risk factors in this patient population have not been extensively studied. Objective: To investigate the rates of and risk factors associated with thrombotic events in patients with HES, including markers of clonal hematopoiesis as evidenced by molecular aberrations on next-generation sequencing. Design, Setting, and Participants: This retrospective cohort study evaluated patients seen at Brigham and Women's Hospital and Harvard Medical School in Boston, Massachusetts, from January 1, 2015, to January 1, 2020. Patients who had hypereosinophilia with an absolute eosinophil count of 1500 cells/µL or greater on 2 separate occasions at least 1 month apart and who underwent genetic or molecular testing as part of their work-up were included. Patients with secondary eosinophilia were excluded. Main Outcomes and Measures: Symptomatic and asymptomatic arterial and venous thrombotic events after the diagnosis of HES and all-cause death. Results: A total of 71 patients (median age, 58 years [interquartile range (IQR), 43-67 years]; 36 women [51%]; 57 White patients [80%]) were included. Patients had a median follow-up time of 29 months (IQR, 19-49 months). Seventeen patients (24%) had 1 or more thrombotic events, including 11 venous thromboembolic events and 11 arterial thrombotic events (8 patients had ≥1 event and 3 patients had recurrent events). Patients with 1 or more thrombotic events had a higher median Eastern Cooperative Oncology Group performance status (median, 1 [IQR, 1-2] vs 0 [IQR, 0-1]; P = .002), had more frequent cardiac involvement (7 of 17 events [41%] vs 6 of 54 events [11%]; P = .01), more frequently received treatment (17 of 17 events [100%] vs 40 of 54 events [74%]; P = .02), and had more molecular aberrations on next-generation sequencing (12 of 17 [71%] vs 12 of 54 [26%]; P = .003) vs patients without thrombosis. After multivariable analysis, the presence of molecular aberration was associated with increased odds of thrombosis (adjusted odds ratio, 5.4; 95% CI, 1.1-27.7). Death occurred more frequently in patients with thrombotic events compared with those without (6 of 17 [35%] vs 2 of 54 [4%]; P = .002) and in patients with molecular aberrations compared with those without (6 of 24 [25%] vs 1 of 40 [3%]; P = .009), although only thrombotic events were significantly associated with increased odds of death after multivariable analysis. Conclusions and Relevance: In this cohort study, thrombosis was common in patients with HES and was significantly associated with increased risk of death.

COVID-19 and coagulation: bleeding and thrombotic manifestations of SARS-CoV-2 infection.

Patients with coronavirus disease 2019 (COVID-19) have elevated D-dimer levels. Early reports describe high venous thromboembolism (VTE) and disseminated intravascular coagulation (DIC) rates, but data are limited. This multicenter retrospective study describes the rate and severity of hemostatic and thrombotic complications of 400 hospital-admitted COVID-19 patients (144 critically ill) primarily receiving standard-dose prophylactic anticoagulation. Coagulation and inflammatory parameters were compared between patients with and without coagulation-associated complications. Multivariable logistic models examined the utility of these markers in predicting coagulation-associated complications, critical illness, and death. The radiographically confirmed VTE rate was 4.8% (95% confidence interval [CI], 2.9-7.3), and the overall thrombotic complication rate was 9.5% (95% CI, 6.8-12.8). The overall and major bleeding rates were 4.8% (95% CI, 2.9-7.3) and 2.3% (95% CI, 1.0-4.2), respectively. In the critically ill, radiographically confirmed VTE and major bleeding rates were 7.6% (95% CI, 3.9-13.3) and 5.6% (95% CI, 2.4-10.7), respectively. Elevated D-dimer at initial presentation was predictive of coagulation-associated complications during hospitalization (D-dimer >2500 ng/mL, adjusted odds ratio [OR] for thrombosis, 6.79 [95% CI, 2.39-19.30]; adjusted OR for bleeding, 3.56 [95% CI, 1.01-12.66]), critical illness, and death. Additional markers at initial presentation predictive of thrombosis during hospitalization included platelet count >450 × 109/L (adjusted OR, 3.56 [95% CI, 1.27-9.97]), C-reactive protein (CRP) >100 mg/L (adjusted OR, 2.71 [95% CI, 1.26-5.86]), and erythrocyte sedimentation rate (ESR) >40 mm/h (adjusted OR, 2.64 [95% CI, 1.07-6.51]). ESR, CRP, fibrinogen, ferritin, and procalcitonin were higher in patients with thrombotic complications than in those without. DIC, clinically relevant thrombocytopenia, and reduced fibrinogen were rare and were associated with significant bleeding manifestations. Given the observed bleeding rates, randomized trials are needed to determine any potential benefit of intensified anticoagulant prophylaxis in COVID-19 patients.

Differentiation of Patients with Symptomatic Low von Willebrand Factor from Those with Asymptomatic Low von Willebrand Factor.

BACKGROUND: Accurate diagnosis of symptomatic low von Willebrand factor (VWF) remains a major challenge in von Willebrand disease (VWD). However, present tests do not adequately take into account flow forces that, at very high shear rates, reveal a weakness in the VWF-platelet glycoprotein glycoprotein Ib bond in normal subjects. The degree of this weakness is greater in symptomatic, but not asymptomatic, low VWF. OBJECTIVE: The aim of this study is to distinguish patients with symptomatic low VWF (levels in the 30-50 IU/dL range) from those with asymptomatic low VWF and normal subjects. METHODS: We measured platelet adhesion (PA)/aggregation in our novel microfluidic flow system that permits real-time assessment of PA (surface coverage) and PA/aggregation (V, aggregate volume) using epifluorescence digital videomicroscopy in flowing noncitrated whole blood at 4,000 second-1. Blood samples from 24 low VWF patients and 15 normal subjects were collected into plastic tubes containing 4 U/mL enoxaparin. MetaMorph software was used to quantify rates of PA and V increase. RESULTS: Rates of PA increase showed a bimodal distribution, with values for 16/24 patients (Group I) all below the 2.5th percentile of normal, and values for 8/24 patients (Group II) similar to controls. Bleeding scores (mean ± standard error) were 5.50 ± 0.45 versus 2.75 ± 0.45 (p = 0.00077), and 10 clinically significant bleeding events were observed in seven versus zero (p = 0.0295) Group I and Group II subjects, respectively. CONCLUSION: The present approach may offer a definitive means to distinguish symptomatic low VWF from either asymptomatic low VWF or normal controls.

Identification and characterization of novel mutations implicated in congenital fibrinogen disorders.

INTRODUCTION: Fibrinogen is a complex molecule comprised of two sets of Aα, Bß, and γ chains. Fibrinogen deficiencies can lead to the development of bleeding or thromboembolic events. The objective of this study was to perform DNA sequence analysis of patients with clinical fibrinogen abnormalities, and to perform genotype-phenotype correlations. MATERIALS AND METHODS: DNA from 31 patients was sequenced to evaluate disease-causing mutations in the three fibrinogen genes: FGA,FGB, and FGG. Clinical data were extracted from medical records or from consultation with referring hematologists. Fibrinogen antigen and functional (Clauss method) assays, as well as reptilase time (RT) and thrombin time (TT) were obtained for each patient. Molecular modeling was used to simulate the functional impact of specific missense variants on the overall protein structure. RESULTS: Seventeen mutations, including six novel mutations, were identified in the three fibrinogen genes. There was little correlation between genotype and phenotype. Molecular modeling predicted a substantial conformational change for a novel variant, FGG p.Ala289Asp, leading to a more rigid molecule in a region critical for polymerization and alignment of the fibrin monomers. This mutation is associated with both bleeding and clotting in the two affected individuals. CONCLUSIONS: Robust genotype-phenotype correlations are difficult to establish for fibrinogen disorders. Molecular modeling might represent a valuable tool for understanding the function of certain missense fibrinogen mutations but those should be followed by functional studies. It is likely that genetic and environmental modifiers account for the incomplete penetrance and variable expressivity that characterize fibrinogen disorders.

Effects of red-cell storage duration on patients undergoing cardiac surgery.

BACKGROUND: Some observational studies have reported that transfusion of red-cell units that have been stored for more than 2 to 3 weeks is associated with serious, even fatal, adverse events. Patients undergoing cardiac surgery may be especially vulnerable to the adverse effects of transfusion. METHODS: We conducted a randomized trial at multiple sites from 2010 to 2014. Participants 12 years of age or older who were undergoing complex cardiac surgery and were likely to undergo transfusion of red cells were randomly assigned to receive leukocyte-reduced red cells stored for 10 days or less (shorter-term storage group) or for 21 days or more (longer-term storage group) for all intraoperative and postoperative transfusions. The primary outcome was the change in Multiple Organ Dysfunction Score (MODS; range, 0 to 24, with higher scores indicating more severe organ dysfunction) from the preoperative score to the highest composite score through day 7 or the time of death or discharge. RESULTS: The median storage time of red-cell units provided to the 1098 participants who received red-cell transfusion was 7 days in the shorter-term storage group and 28 days in the longer-term storage group. The mean change in MODS was an increase of 8.5 and 8.7 points, respectively (95% confidence interval for the difference, -0.6 to 0.3; P=0.44). The 7-day mortality was 2.8% in the shorter-term storage group and 2.0% in the longer-term storage group (P=0.43); 28-day mortality was 4.4% and 5.3%, respectively (P=0.57). Adverse events did not differ significantly between groups except that hyperbilirubinemia was more common in the longer-term storage group. CONCLUSIONS: The duration of red-cell storage was not associated with significant differences in the change in MODS. We did not find that the transfusion of red cells stored for 10 days or less was superior to the transfusion of red cells stored for 21 days or more among patients 12 years of age or older who were undergoing complex cardiac surgery. (Funded by the National Heart, Lung, and Blood Institute; RECESS ClinicalTrials.gov number, NCT00991341.).

A confirmed case of agranulocytosis after use of cocaine contaminated with levamisole.

More than 2 million Americans use cocaine each month (National Survey on Drug Use and Health, Department of Health and Human Services: Substance Abuse and Mental Health Services Administration (SAMHSA) & Office of Applied Studies (OAS), Rockville, MD 2007). Starting in early 2003, South American cocaine cartels began to add levamisole, a pharmaceutical agent, to bulk cocaine prior to shipment to the USA (Valentino and Fuentecilla 2005). A dramatic increase in the prevalence of levamisole in cocaine was noted in early 2008. By October, 30% of cocaine bricks analyzed by the United States Drug Enforcement Administration contained levamisole (Casale et al. 2008). Exposure to levamisole can cause agranulocytosis (Amery and Bruynseels 1992). We report the first confirmed case of agranulocytosis associated with consumption of levamisole-contaminated cocaine in the USA. A previously healthy adult male presented to the emergency department with 5 days of mouth pain. He admitted to chronic active ethanol and crack cocaine abuse. Laboratory studies revealed severe neutropenia, with an absolute neutrophil count of 19 cells/mm³ (normal = 1,500-8,000 cells/mm³). A urine screen for drugs of abuse was positive for cocaine metabolites and opiates. Evaluation of a peripheral blood smear showed leukopenia with severe absolute neutropenia. A bone marrow biopsy revealed recently injured bone marrow showing early recovery. While in the hospital, the patient had little spontaneous bone marrow recovery. He received granulocyte colony-stimulating factor with improvement in peripheral white blood cell counts. The residue in the patient's crack pipe contained 10% levamisole. Subsequently, levamisole was detected in the patient's urine. Levamisole-associated agranulocytosis should be considered in the diagnosis of patients who present with neutropenia and a history or evidence of cocaine use.

A disease management protocol for outpatient perioperative bridge therapy with enoxaparin in patients requiring temporary interruption of long-term oral anticoagulation.

STUDY OBJECTIVE: Traditional perioperative bridge therapy for patients receiving long-term oral anticoagulation involves weight-adjusted intravenous unfractionated heparin (UFH) in the perioperative period during temporary discontinuation of the oral anticoagulant. We sought to determine whether an alternate strategy of outpatient-based perioperative disease management with low-molecular-weight heparin (LMWH) as bridge therapy provides the potential for cost savings. DESIGN: Retrospective review of all clinic notes from an anticoagulation clinic. SETTING: An integrated, staff-model health maintenance organization. PATIENTS: Patients receiving long-term warfarin therapy from January 1998-March 2002 who received perioperative bridge therapy with the LMWH enoxaparin 1 mg/kg twice/day subcutaneously MEASUREMENTS AND MAIN RESULTS: A total of 126 bridge therapy encounters in 84 patients receiving LMWH as perioperative bridge therapy were identified, with 48 of those encounters involving patients with at least one mechanical heart valve. A total of 1108 hospital bed days were saved. Based on 1996 cost estimates, the total approximate cost savings for the 4.25 years of the outpatient bridge therapy program was dollars 903,020. No thrombotic events were reported. Three major hemorrhagic events that required discontinuation of LMWH were reported. CONCLUSION: Outpatient-based disease management protocols and the LMWH enoxaparin as bridge therapy during temporary discontinuation of warfarin for an elective surgical procedure resulted in cost savings of approximately dollars 212,475/year in an integrated health maintenance organization. In addition, this strategy appears both safe and effective.