Optimization of laboratory diagnosis of heparin-induced thrombocytopenia using HemosIL-AcuStar-HIT-IgG assay.

OBJECTIVE: The aim of this study was to determine an optimal cutoff value for the newly available HemosIL-AcuStar-HIT-IgG assay (AcuStar) for the diagnosis of heparin-induced thrombocytopenia (HIT). METHOD: We evaluated the performance of AcuStar using serotonin release assay (SRA) as the gold standard and incorporated 4T score calculation in a cohort of suspected HIT cases. Statistical analysis was performed to determine optimal cutoff value for the diagnosis of HIT. RESULT: A diagnosis of HIT can be excluded with a platelet factor 4 (PF4) value of <0.4 U/mL by AcuStar and 4T score in the low-risk category (≤3). All other cases will require confirmation with a functional test. CONCLUSION: Our study resulted in the implementation of a diagnostic algorithm for laboratory diagnosis of HIT, which incorporates pretest calculation of 4T score and AcuStar as a screening test, with reflex confirmation by SRA. This new algorithm resulted in extended hours of test availability and a more rapid turnaround time in reporting PF4 results.

Low value of inherited thrombophilia testing among patients with stroke or transient ischemic attack: A three-year retrospective study.

BACKGROUND/PURPOSE: Inherited thrombophilia testing in the acute inpatient setting is controversial and expensive, and rarely changes clinical management. We evaluated ordering patterns and results of inpatient inherited thrombophilia testing for patients who presented with an isolated acute ischemic stroke or transient ischemic attack (TIA) without concurrent venous thromboembolism. METHODS: We retrospectively analyzed patients admitted for acute ischemic stroke or TIA between January 1st, 2019 and December 31st, 2021 at Thomas Jefferson University Hospitals in Philadelphia, PA and who underwent inherited thrombophilia testing during the hospital admission. Charts were reviewed to determine stroke risk factors, test results, and clinical management. RESULTS: Among 2108 patients admitted for acute ischemic stroke or TIA (including branch and central retinal artery occlusions) during the study period, the study included 249 patients (median age 49.0 years, 50.2% female) who underwent inpatient testing for factor V Leiden, prothrombin G20210A variant, hyperhomocysteinemia, PAI-1 elevation, and deficiencies of protein C and S and antithrombin. 42.2% of patients had at least one abnormal test, and among the 1035 tests ordered, 14.3% resulted abnormal. However, 28% of abnormal tests were borderline positive antigen or activity assays that likely represented false positives. There was no significant difference in the likelihood of a positive test among patients without stroke risk factors vs those with risk factors (47.1% vs 40.9%, P = .428), nor any significant difference between those under vs over age 50 years (45.7% vs 38.3%, P = .237). No patients with an abnormal result had their clinical management changed as a result. Charges for the tests totaled $468,588 USD. CONCLUSIONS: Inherited thrombophilia testing in the hospital immediately following isolated acute arterial ischemic stroke or TIA was associated with high rates of likely false positive results and was expensive. Positive results did not change clinical management in a single case.

Perioperative Outcomes of Patients with Bleeding Disorders Undergoing Major Surgery at an Academic Hemophilia Treatment Center.

Persons with bleeding disorders (PwBD) are at high risk for bleeding with invasive procedures. However, the risk of bleeding in PwBD undergoing major surgery and outcomes of patients managed perioperatively at a hemophilia treatment center (HTC) are not well described. We performed a retrospective review of surgical outcomes among PwBD undergoing major surgery between January 1st, 2017 and December 31st, 2019 at the Cardeza Foundation Hemophilia and Thrombosis Center in Philadelphia, PA. The primary outcome was postoperative bleeding, assessed according to the ISTH-SSC's 2010 definition. Secondary outcomes included use of unplanned postoperative hemostatic therapy, LOS, and 30-day readmission rate. Results were compared to non-PwBD population from a surgical database, matched for surgery, age, and sex. During the study period, 50 PwBD underwent 63 major surgeries. The most common diagnoses were VWD (64%) and hemophilia A (20.0%). The most common surgical procedure category was orthopedic (33.3%), predominantly arthroplasties. Postoperatively,4.8% of procedures were complicated by major bleeding and 1.6% by non-major bleeding. The mean LOS was 1.65 days, and 30-day readmission rate was 1.6%. In comparison to matched, non-PwBD patients in a national surgical database undergoing the same procedures, study patients had a similar rate of bleeding complications per procedure (5.0% vs 1.04% P = .071, Fisher's exact test). PwBD undergoing major surgeries have low rates of major bleeding when receiving comprehensive care at an HTC. Bleeding and hospital readmission rates were similar to non-PwBD baseline in a large database.

Case series: coronavirus disease 2019 infection as a precipitant of atypical hemolytic uremic syndrome: two case reports.

BACKGROUND: Atypical hemolytic uremic syndrome is an exceedingly rare thrombotic microangiopathy caused by accelerated activation of the alternative complement pathway. CASE PRESENTATION: Here, we report two cases of patients presenting with suspected atypical hemolytic uremic syndrome precipitated by coronavirus disease 2019 infection. The first patient, a 25-year-old Hispanic male, had one prior episode of thrombotic microangiopathy presumed to be atypical hemolytic uremic syndrome precipitated by influenza A, and re-presented with thrombocytopenia, microangiopathic hemolytic anemia, nonoliguric renal failure, and normal ADAMTS13 activity, with confirmed coronavirus disease 2019 positivity. The second patient, a 31-year-old Caucasian female, had no personal history of thrombotic microangiopathy, though reported a family history of suspected atypical hemolytic uremic syndrome. She presented with similar laboratory derangements, oliguric renal failure requiring hemodialysis, and confirmed coronavirus disease 2019 positivity. Both patients were treated with eculizumab with complete resolution of their hematologic and renal complications. CONCLUSION: To our knowledge, this represents the largest case series of atypical hemolytic uremic syndrome precipitated by coronavirus disease 2019 in adults.

COVID-19 and thrombosis: searching for evidence.

Early in the pandemic, COVID-19-related increases in rates of venous and arterial thromboembolism were seen. Many observational studies suggested a benefit of prophylactic anticoagulation for hospitalized patients using various dosing strategies. Randomized trials were initiated to compare the efficacy of these different options in acutely ill and critically ill inpatients as the concept of immune-mediated inflammatory microthrombosis emerged. We present a case-based review of how we approach thromboembolic prophylaxis in COVID-19 and briefly discuss the epidemiology, the pathophysiology, and the rare occurrence of vaccine-induced thrombotic thrombocytopenia.

Secondary stroke prevention in patients with patent foramen ovale.

PURPOSE OF REVIEW: Although a patent foramen ovale (PFO) is an established risk factor for cryptogenic ischemic stroke, strategies for secondary prevention remain controversial. Increasing evidence over the past decade from well designed clinical trials supports transcatheter PFO closure for selected patients whose stroke was likely attributable to the PFO. However, patient selection using imaging findings, clinical scoring systems, and in some cases, thrombophilia testing, is crucial for determining patients most likely to benefit from closure, anticoagulation, or antiplatelet therapy. RECENT FINDINGS: Recent studies have found that patients with a high Risk of Paradoxical Embolism (RoPE) score and those with a thrombophilia benefit more from closure than medical therapy (including antiplatelet or anticoagulant therapy) alone. Meta-analyses have demonstrated an increased short-term risk of atrial fibrillation in closure patients, and that residual shunt after closure predicts stroke recurrence. Last, recent data have been inconclusive as to whether patients receiving medical therapy only benefit more from anticoagulation or antiplatelet therapy, so this remains an area of controversy. SUMMARY: Transcatheter PFO closure is an evidence-based, guideline-supported therapy for secondary stroke prevention in patients with a PFO and cryptogenic stroke. However, proper patient selection is critical to achieve benefit, and recent studies have helped clarify those patients most likely to benefit from closure.

Primary central nervous system plasmablastic lymphoma in an HIV-positive patient.

Plasmablastic lymphoma (PBL) is a rare subtype of diffuse large B-cell lymphoma, highly associated with HIV and Epstein-Barr virus (EBV) infections. It commonly presents in extranodal sites, often an oral mass, but reports of primary central nervous system PBL (PCNSPBL) are exceedingly rare. Here, we report on a 33-year-old man with newly diagnosed HIV infection who presented with acute-onset unilateral visual disturbance and was found to have biopsy-proven PCNSPBL. The neoplastic cells displayed a plasmacytoid appearance, with the expression of CD38 and CD138, and were positive for EBV by in situ hybridisation for EBV-encoded RNA. Systemic workup revealed the presence of Kaposi sarcoma, but no evidence of lymphoma. He is currently being treated with high-dose methotrexate, as well as antiretroviral therapy for his HIV infection, and has achieved a complete response.

The Role of B Cell Targeting in Chronic Graft-Versus-Host Disease.

Chronic graft-versus-host disease (cGVHD) is a leading cause of late morbidity and mortality following allogeneic stem cell transplantation. Current therapies, including corticosteroids and calcineurin inhibitors, are only effective in roughly 50% of cases; therefore, new treatment strategies are under investigation. What was previously felt to be a T cell disease has more recently been shown to involve activation of both T and B cells, as well as a number of cytokines. With a better understanding of its pathophysiology have come more expansive preclinical and clinical trials, many focused on B cell signaling. This report briefly reviews our current understanding of cGVHD pathophysiology and reviews clinical and preclinical trials with B cell-targeted agents.