Limb ischemia due to spontaneous heparin-induced thrombocytopenia as the primary presentation of acute COVID-19 infection.

Heparin-induced thrombocytopenia (HIT) occurs with the development of IgG antibodies that bind complexes of heparin and platelet factor 4 (PF4), which activate platelets and result in a profoundly prothrombotic condition. In rare instances, this syndrome develops in the absence of proximate heparin administration, referred to as spontaneous HIT, for which less than three dozen cases have been reported. Spontaneous HIT is considered a subtype of "autoimmune HIT" (aHIT), characterized by platelet activation in the serotonin release assay (SRA) without the addition of exogenous heparin. Here, we report spontaneous HIT as the presenting feature in a patient with 2019 coronavirus disease infection (COVID-19).A 66-year-old male presented with progressive leg pain and was found to have a platelet count of 39 × 109/L and multiple lower extremity arterial thromboses requiring fasciotomy and thrombectomy. He had no recent hospitalization, heparin exposure, vaccinations, or known thrombophilia. He had a strongly positive IgG-specific enzyme-linked immunosorbent assay for heparin-PF4 antibodies, and the SRA was strongly positive both with and without the addition of heparin. He was treated successfully with bivalirudin, intravenous immunoglobulin, and apixaban.

Empiric Therapy with BRAF and MEK Inhibitors in Metastatic Melanoma.

BRAF and MEK inhibitors are highly active in the setting of BRAF V600 mutant melanoma. Rarely, patients without previous testing present with fulminant progression necessitating emergent treatment prior to BRAF testing results. The safety and efficacy of empiric treatment in this setting is unclear. Herein, we present two patients treated with empiric BRAF and MEK inhibitors, resulting in dramatic clinical improvement in one patient later found to have a BRAF mutation, and lack of improvement (but no accelerated progression) in a patient lacking this mutation. Empiric BRAF and MEK inhibitor treatment should not be routinely pursued but may be given safely in rare, emergent situations.

Systematic review of infectious events with the Bruton tyrosine kinase inhibitor ibrutinib in the treatment of hematologic malignancies.

OBJECTIVE: Ibrutinib is an irreversible inhibitor of Bruton tyrosine kinase (BTK) in B lymphocytes as well as other kinases including interleukin-2-inducible T-cell kinase (ITK) in CD4+ Th2 regulatory T cells. Increased infections have been observed in patients taking ibrutinib. The overall incidence has not been systematically evaluated. METHODS: The published literature and conference abstracts of prospective clinical trials using ibrutinib in hematologic malignancies were identified and reviewed using PubMed, Google Scholar, and HemOnc.org per PRISMA guidelines. Infectious events with a focus on pneumonia were collated per the Common Terminology Criteria for Adverse Events Version 4.03 grading. RESULTS: Infectious complications are common, occurring in 56% of patients taking single-agent ibrutinib and 52% of those on combination therapy. Approximately one in 5 patients developed pneumonia, which was the major contributor to a 2% rate of death from infections. Many of the cases of pneumonia were due to opportunistic pathogens. CONCLUSIONS: Ibrutinib use requires prudent consideration of the impacts on host immunity. We identified a high rate of serious adverse infectious events within prospective clinical trials. Data suggest a role of both BTK and ITK inhibition for the increased events. There was considerable variability in the reporting of adverse events between trials, journals, and conference reports.

Idiopathic Multicentric Castleman Disease With Thrombocytopenia, Anasarca, Fever, Reticulin Fibrosis/Renal Insufficiency, and Organomegaly (TAFRO) Syndrome in a Liver Transplant Recipient.

Idiopathic multicentric Castleman disease is a rare lymphoproliferative disorder that can be potentially fatal without timely diagnosis and treatment. We describe the first-ever reported occurrence of idiopathic multicentric Castleman disease with thrombocytopenia, anasarca, fever, reticulin fibrosis/renal insufficiency, and organomegaly syndrome in a liver transplant recipient. The diagnosis was challenging as the clinical presentation closely mimicked decompensated cirrhosis, and the profound thrombocytopenia limited tissue diagnosis. However, we were able to establish the diagnosis and treat it effectively. This case report signifies that a high index of suspicion and aggressive treatment can be lifesaving in liver transplant recipients presenting with this rare disorder.

A real-time prognostic model for venous thromboembolic events among hospitalized adults.

Background: Hospital-acquired venous thromboembolism (HA-VTE) is a leading cause of morbidity and mortality among hospitalized adults. Guidelines recommend use of a risk-prediction model to estimate HA-VTE risk for individual patients. Extant models do not perform well for broad patient populations and are not conducive to automation in clinical practice. Objectives: To develop an automated, real-time prognostic model for venous thromboembolism during hospitalization among all adult inpatients using readily available data from the electronic health record. Methods: The derivation cohort included inpatient hospitalizations ("encounters") for patients ≥16 years old at Vanderbilt University Medical Center between 2018 and 2020 (n = 132,330). HA-VTE events were identified using International Classification of Diseases, 10th Revision, codes. The prognostic model was developed using least absolute shrinkage and selection operator regression. Temporal external validation was performed in a validation cohort of encounters between 2021 and 2022 (n = 62,546). Prediction performance was assessed by discrimination accuracy (C statistic) and calibration (integrated calibration index). Results: There were 1187 HA-VTEs in the derivation cohort (9.0 per 1000 encounters) and 864 in the validation cohort (13.8 per 1000 encounters). The prognostic model included 25 variables, with placement of a central line among the most important predictors. Prediction performance of the model was excellent (C statistic, 0.891; 95% CI, 0.882-0.900; integrated calibration index, 0.001). The model performed similarly well across subgroups of patients defined by age, sex, race, and type of admission. Conclusion: This fully automated prognostic model uses readily available data from the electronic health record, exhibits superior prediction performance compared with existing models, and generates granular risk stratification in the form of a predicted probability of HA-VTE for each patient.

Chromogenic and Clot-Based Bivalirudin Assays for Monitoring Anticoagulation.

BACKGROUND: Direct thrombin inhibitors (DTIs) are usually monitored with the activated partial thromboplastin time (aPTT) or activated clotting time (ACT). Both are complex assays with multiple enzymatic steps, and performance may be influenced by physiologic and pathologic factors unrelated to the DTI. Simpler systems, such as clot-based dilute thrombin time (dTT) and chromogenic anti-factor IIa assays, have been developed for monitoring DTIs, but there is limited data on their performance in clinical settings. METHODS: Medical records of patients who received bivalirudin between March 2020 and April 2022 at a single institution were reviewed for demographic data and adverse outcomes. Plasma samples drawn for aPTT testing were analyzed with chromogenic anti-IIa and dTT bivalirudin assays. Results were compared to bivalirudin dosing. RESULTS: Results of aPTT assays from 32 patients were compared with the chromogenic (n = 136) and dTT (n = 120) bivalirudin assays. Correlations between the aPTT and the chromogenic and dTT assays were poor (Spearman coefficients 0.55 and 0.62, respectively). There was a stronger correlation when results of the chromogenic and dTT assays were compared to each other (Spearman coefficient 0.92). When assay results were compared to bivalirudin dose, there were stronger correlations with the chromogenic and dTT assays than with the aPTT (Spearman coefficients 0.51, 0.63 and 0.22, respectively). CONCLUSIONS: There was considerable variation between results of specific bivalirudin assays and the aPTT. While bivalirudin assay results correlated better with administered drug dose, suggesting improving reliability, more studies are needed to determine if there is correlation between testing and clinical outcomes.

Effects of Specialist Palliative Care for Patients Undergoing Major Abdominal Surgery for Cancer: A Randomized Clinical Trial.

Importance: Specialist palliative care benefits patients undergoing medical treatment of cancer; however, data are lacking on whether patients undergoing surgery for cancer similarly benefit from specialist palliative care. Objective: To determine the effect of a specialist palliative care intervention on patients undergoing surgery for cure or durable control of cancer. Design, Setting, and Participants: This was a single-center randomized clinical trial conducted from March 1, 2018, to October 28, 2021. Patients scheduled for specified intra-abdominal cancer operations were recruited from an academic urban referral center in the Southeastern US. Intervention: Preoperative consultation with palliative care specialists and postoperative inpatient and outpatient palliative care follow-up for 90 days. Main Outcomes and Measures: The prespecified primary end point was physical and functional quality of life (QoL) at postoperative day (POD) 90, measured by the Functional Assessment of Cancer Therapy-General (FACT-G) Trial Outcome Index (TOI), which is scored on a range of 0 to 56 with higher scores representing higher physical and functional QoL. Prespecified secondary end points included overall QoL at POD 90 measured by FACT-G, days alive at home until POD 90, and 1-year overall survival. Multivariable proportional odds logistic regression and Cox proportional hazards regression models were used to test the hypothesis that the intervention improved each of these end points relative to usual care in an intention-to-treat analysis. Results: A total of 235 eligible patients (median [IQR] age, 65.0 [56.8-71.1] years; 141 male [60.0%]) were randomly assigned to the intervention or usual care group in a 1:1 ratio. Specialist palliative care was received by 114 patients (97%) in the intervention group and 1 patient (1%) in the usual care group. Adjusted median scores on the FACT-G TOI measure of physical and functional QoL did not differ between groups (intervention score, 46.77; 95% CI, 44.18-49.04; usual care score, 46.23; 95% CI, 43.08-48.14; P = .46). Intervention vs usual care group odds ratio (OR) was 1.17 (95% CI, 0.77-1.80). Palliative care did not improve overall QoL measured by the FACT-G score (intervention vs usual care OR, 1.09; 95% CI, 0.75-1.58), days alive at home (OR, 0.87; 95% CI, 0.69-1.11), or 1-year overall survival (hazard ratio, 0.97; 95% CI, 0.50-1.88). Conclusions and Relevance: This randomized clinical trial showed no evidence that early specialist palliative care improves the QoL of patients undergoing nonpalliative cancer operations. Trial Registration: ClinicalTrials.gov Identifier: NCT03436290.

Serial Thromboelastography and the Development of Venous Thromboembolism in Critically Ill Patients With COVID-19.

To test the hypothesis that relatively lower clot strength on thromboelastography maximum amplitude (MA) is associated with development of venous thromboembolism (VTE) in critically ill patients with COVID-19. DESIGN: Prospective, observational cohort study. SETTING: Tertiary care, academic medical center in Nashville, TN. PATIENTS: Patients with acute respiratory failure from COVID-19 pneumonia admitted to the adult medical ICU without known VTE at enrollment. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Ninety-eight consecutive critically ill adults with laboratory-confirmed COVID-19 were enrolled. Thromboelastography parameters and conventional coagulation parameters were measured on days 0 (within 48 hr of ICU admission), 3, 5, and 7 after enrollment. The primary outcome was diagnosis of VTE with confirmed deep venous thrombosis and/or pulmonary embolism by clinical imaging or autopsy. Twenty-six patients developed a VTE. Multivariable regression controlling for antiplatelet exposure and anticoagulation dose with death as a competing risk found that lower MA was associated with increased risk of VTE. Each 1 mm increase in enrollment and peak MA was associated with an 8% and 14% decrease in the risk of VTE, respectively (enrollment MA: subdistribution hazard ratio [SHR], 0.92; 95% CI, 0.87-0.97; p = 0.003 and peak MA: SHR, 0.86; 95% CI, 0.81-0.91; p < 0.001). Lower enrollment platelet counts and fibrinogen levels were also associated with increased risk of VTE (p = 0.002 and p = 0.01, respectively). Platelet count and fibrinogen level were positively associated with MA (multivariable model: adjusted R 2 = 0.51; p < 0.001). CONCLUSIONS: When controlling for the competing risk of death, lower enrollment and peak MA were associated with increased risk of VTE. Lower platelet counts and fibrinogen levels at enrollment were associated with increased risk of VTE. The association of diminished MA, platelet counts, and fibrinogen with VTE may suggest a relative consumptive coagulopathy in critically ill patients with COVID-19.

Thromboelastography Parameters and Platelet Count on Admission to the ICU and the Development of Venous Thromboembolism in Patients With Coronavirus Disease 2019.

OBJECTIVES: Determine if thromboelastography parameters and platelet count on the day of ICU admission are associated with the development of venous thromboembolism in patients with coronavirus disease 2019. DESIGN: Prospective, observational cohort study. SETTING: Tertiary-care, academic medical center in Nashville, TN. PATIENTS: Patients with coronavirus disease 2019 pneumonia and acute respiratory failure admitted to the adult ICU without venous thromboembolism at the time of ICU admission. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was development of venous thromboembolism during the index hospitalization. Venous thromboembolism was defined by clinical imaging or autopsy, demonstrating deep vein thrombosis or pulmonary embolism. Forty consecutive critically ill adults with laboratory-confirmed coronavirus disease 2019 were enrolled; 37 (92.5%) were hypercoagulable by at least one thromboelastography parameter at the time of ICU admission and 12 (30%) met the primary outcome of venous thromboembolism during the index hospitalization. Patients who developed venous thromboembolism had decreased measures of clotting (maximum amplitude, alpha angle, shear elastic modulus parameter, and clotting index) on ICU admission thromboelastography compared with patients who did not develop venous thromboembolism (p < 0.05 for all measures). For each individual thromboelastography parameter used to dichotomize patients as hypercoagulable, the rate of venous thromboembolism was not higher in those identified as hypercoagulable; in fact, the venous thromboembolism rate was higher in patients who were not hypercoagulable by thromboelastography for maximum amplitude (p = 0.04) and alpha angle (p = 0.001). Platelet count was positively correlated with maximum amplitude, alpha angle, G parameter, and clotting index, and significantly lower in patients who developed venous thromboembolism than those who did not (median 186 vs 278 103/µL, p = 0.046). Venous thromboembolism was associated with inhospital mortality (odds ratio, 6.3; 95% CI, 1.4-29; p = 0.02). CONCLUSIONS: Our data do not support the use of thromboelastography to risk stratify critically ill adults with coronavirus disease 2019 for the development of venous thromboembolism or to guide decisions about anticoagulation. Lower platelet count on ICU admission, which may reflect platelet aggregation, was associated with venous thromboembolism.

Seven decades of chemotherapy clinical trials: a pan-cancer social network analysis.

Clinical trials establish the standard of cancer care, yet the evolution and characteristics of the social dynamics between the people conducting this work remain understudied. We performed a social network analysis of authors publishing chemotherapy-based prospective trials from 1946 to 2018 to understand how social influences, including the role of gender, have influenced the growth and development of this network, which has expanded exponentially from fewer than 50 authors in 1946 to 29,197 in 2018. While 99.4% of authors were directly or indirectly connected by 2018, our results indicate a tendency to predominantly connect with others in the same or similar fields, as well as an increasing disparity in author impact and number of connections. Scale-free effects were evident, with small numbers of individuals having disproportionate impact. Women were under-represented and likelier to have lower impact, shorter productive periods (P < 0.001 for both comparisons), less centrality, and a greater proportion of co-authors in their same subspecialty. The past 30 years were characterized by a trend towards increased authorship by women, with new author parity anticipated in 2032. The network of cancer clinical trialists is best characterized as strategic or mixed-motive, with cooperative and competitive elements influencing its appearance. Network effects such as low centrality, which may limit access to high-profile individuals, likely contribute to the observed disparities.

Plasma contact factors as therapeutic targets.

Direct oral anticoagulants (DOACs) are small molecule inhibitors of the coagulation proteases thrombin and factor Xa that demonstrate comparable efficacy to warfarin for several common indications, while causing less serious bleeding. However, because their targets are required for the normal host-response to bleeding (hemostasis), DOACs are associated with therapy-induced bleeding that limits their use in certain patient populations and clinical situations. The plasma contact factors (factor XII, factor XI, and prekallikrein) initiate blood coagulation in the activated partial thromboplastin time assay. While serving limited roles in hemostasis, pre-clinical and epidemiologic data indicate that these proteins contribute to pathologic coagulation. It is anticipated that drugs targeting the contact factors will reduce risk of thrombosis with minimal impact on hemostasis. Here, we discuss the biochemistry of contact activation, the contributions of contact factors in thrombosis, and novel antithrombotic agents targeting contact factors that are undergoing pre-clinical and early clinical testing.

Effects of Plasma Exchange and Heparin Concentration on the Serotonin Release Assay in Heparin-Induced Thrombocytopenia.

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is a hypercoagulable state caused by a transient antibody to heparin-bound platelet factor 4 (PF4). Treatment involves discontinuing heparin and administering a nonheparin anticoagulant. Procedures requiring heparin, such as cardiopulmonary bypass, are preferably delayed until the offending antibody is no longer detectable. For patients with a high-titer anti-PF4-heparin antibody and who require exposure to heparin, therapeutic plasma exchange (TPE) has been used to remove the antibody. Recent work indicates that a functional assay for detecting platelet-activating antibodies in HIT patients, the serotonin release assay (SRA), is preferable to ELISAs for anti-PF4-heparin antibodies for following the effectiveness of plasma exchange. METHODS: Two cases of acute heparin-induced thrombocytopenia managed with plasma exchange before emergent cardiac surgery were evaluated with SRAs using a range of heparin concentrations that included those used in cardiopulmonary bypass. RESULTS: We observed that a single round of plasma exchange led to greater reduction in platelet reactivity at heparin concentrations between 1 and 3 U/mL than at lower concentrations, consistent with the impression that heparin-PF4-antibody complexes form optimally within a limited heparin concentration range. CONCLUSIONS: The findings suggest there may be a range of heparin concentration in which cardiac surgery may be safely performed in HIT patients, and that a single TPE in an emergent setting may lower antibody concentration sufficiently to lower platelet reactivity in the presence of heparin.

Cerebral Amyloid Angiopathy Presenting with Synchronous Bilateral Intracerebral Macrohemorrhages.

Cerebral amyloid angiopathy (CAA) is the deposition of amyloid proteins in the cerebrovasculature, which can lead to intracerebral hemorrhage. Intracerebral hemorrhage in CAA often presents with microhemorrhages and, less frequently, with more devastating macrohemorrhages. We present a case of CAA-related synchronous bilateral intracerebral macrohemorrhage which, to our knowledge, has yet to be reported in the literature, and postulate its relationship to antiplatelet therapy and transient elevations in blood pressure.

The immunophenotype of pre-TALL/LBL revisited.

Flow cytometric analysis of cluster of differentiation (CD) markers in abnormal lymphocyte populations is crucial in the diagnosis of precursor T cell acute lymphoblastic leukemia (T-ALL)/lymphoblastic lymphoma (LBL). The World Health Organization (WHO) suggested immunophenotype for pre-T ALL/LBL typically includes the expression of TdT, cCD3, and CD7, while CD2, CD3, CD4, CD5, CD8, and CD10 are variably expressed. The myeloid antigens CD13 and CD33 are usually positive, whereas CD117 and cCD79a are infrequently expressed. Furthermore, there is frequent dual expression of CD4 and CD8. In the present investigation, 19 cases of pre-TALL/LBL were analyzed for selected CD marker expression. Fifteen of 19 cases studied were evaluated for TdT, cCD3, and cCD79a expression. Eleven (73.3%) positively expressed TdT, 15 (100%) positively expressed cCD3, and 9 (60%) positively expressed cCD79a. Of the 17 cases analyzed for CD7, CD5, and CD10 expression, CD7 and CD5 were positive in all 17 (100%) cases, whereas CD10 was positive in 8 (47.1%) cases. Of the 18 cases evaluated for CD2, CD3, CD4, CD8, and dual expression of CD4 and CD8, CD2 was expressed in 14 (77.8%), while CD3 was expressed in 7 (38.9%) cases. CD4 was positive in 11 (61.1%), and CD8 was expressed in 9 (50%). Dual expression of CD4 and CD8 occurred in only 4 (22.2%) of the cases. Of the 16 analyzed for CD13, CD33, and CD117, only 1 case (6.3%) expressed CD13, while 2 (12.5%) cases expressed CD33 and CD117. Thus, these data point to the need for a more extensive study to reevaluate the current WHO defined immunophenotype used in the diagnosis of pre-TALL/LBL.

Antigenic transformation in plasma cell dyscrasia.

The WHO immunophenotype for plasma cell myeloma is deletion of CD19 and CD20, usual expression of CD38, CD138, and CD56, and occasional expression of CD10. Of the 39 cases of plasma cell dyscrasia in our study, the mean fluorescence intensities (MFI) of CD38, CD138, CD56, and CD19 were quantified in 30 cases. CD19 was absent in 38 of the cases (97.4%), whereas CD138 and CD38 were expressed in all 39 cases (100%). Most cases expressed CD38 and CD138 brightly with MFI values greater than 501, whereas all other marker expression was moderate with MFI greater than 301. Whereas CD38/CD56 dual expression was observed in 25 cases (64.1%), 14 failed to express CD56 (35.9%). CD56 expression was bright in 16 cases (53.3%), moderate in 2 cases (6.7%), and negative in the remaining 12 cases (40%) with MFI values of 200 or less. CD117 expression was positive in 9 of 24 cases (37.5%). In 32 of 39 cases, 27 were negative for CD20 (84.4%) and 28 were negative for CD10 (87.5%). Our results point to the value of quantitative fluorescence intensity in the flow cytometric evaluation of CD molecular expression or deletion in the diagnosis of hematopathologic disorders, such as plasma cell dyscrasia.