The impact of hematology electronic consultations on the management of iron deficiency.

OBJECTIVES: Delays in the evaluation and treatment of iron deficiency can lead to increased disease-related morbidity and mortality. Electronic consultation (e-consult) is a referral modality that allows providers quicker access to recommendations from a specialist based on electronic chart review. While the use of e-consult is expanding in classical hematology, gaps exist in the understanding of patient outcomes related to its use for iron deficiency. METHODS: We randomly selected 200 e-consults and 200 traditional referrals from 3,336 hematology referrals for iron deficiency at a single center. The primary outcomes of the retrospective analysis were: time to completion of the referral, and time to treatment with intravenous iron. Secondary outcomes included recurrence of iron deficiency, need for repeat e-consult, conversion to in-person evaluation, and assessment of whether the etiology of iron deficiency was addressed. RESULTS: E-consults significantly reduced the time from referral to intravenous iron repletion (e-consult, 33 days; traditional referral, 68 days; p < .05). Assessment of the underlying etiology occurred in 70.7% of the e-consult encounters compared to 92.5% of traditional referrals (p < .05). CONCLUSIONS: These findings highlight advantages of e-consults in improving care delivery in iron deficiency, and identifying gaps that can be improved through practice standardization to ensure equitable, high-value care.

Factor XI Inhibition for the Prevention of Catheter-Associated Thrombosis in Patients With Cancer Undergoing Central Line Placement: A Phase 2 Clinical Trial.

BACKGROUND: Despite the ubiquitous utilization of central venous catheters in clinical practice, their use commonly provokes thromboembolism. No prophylactic strategy has shown sufficient efficacy to justify routine use. Coagulation factors FXI (factor XI) and FXII (factor XII) represent novel targets for device-associated thrombosis, which may mitigate bleeding risk. Our objective was to evaluate the safety and efficacy of an anti-FXI mAb (monoclonal antibody), gruticibart (AB023), in a prospective, single-arm study of patients with cancer receiving central line placement. METHODS: We enrolled ambulatory cancer patients undergoing central line placement to receive a single dose of gruticibart (2 mg/kg) administered through the venous catheter within 24 hours of placement and a follow-up surveillance ultrasound at day 14 for evaluation of catheter thrombosis. A parallel, noninterventional study was used as a comparator. RESULTS: In total, 22 subjects (n=11 per study) were enrolled. The overall incidence of catheter-associated thrombosis was 12.5% in the interventional study and 40.0% in the control study. The anti-FXI mAb, gruticibart, significantly prolonged the activated partial thromboplastin time in all subjects on day 14 compared with baseline (P<0.001). Gruticibart was well tolerated and without infusion reactions, drug-related adverse events, or clinically relevant bleeding. Platelet flow cytometry demonstrated no difference in platelet activation following administration of gruticibart. T (thrombin)-AT (antithrombin) and activated FXI-AT complexes increased following central line placement in the control study, which was not demonstrated in our intervention study. CRP (C-reactive protein) did not significantly increase on day 14 in those who received gruticibart, but it did significantly increase in the noninterventional study. CONCLUSIONS: FXI inhibition with gruticibart was well tolerated without any significant adverse or bleeding-related events and resulted in a lower incidence of catheter-associated thrombosis on surveillance ultrasound compared with the published literature and our internal control study. These findings suggest that targeting FXI could represent a safe intervention to prevent catheter thrombosis. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT04465760.

Platelet reactivity and platelet count in women with iron deficiency treated with intravenous iron.

Background: Iron deficiency anemia (IDA) and heavy menstrual bleeding are prevalent, interrelated issues impacting over 300 million premenopausal women worldwide. IDA is generally associated with increased platelet counts; however, the effects of IDA and its correction on platelet function in premenopausal women remain unknown. Objectives: We sought to determine how IDA and intravenous iron affect platelet count and platelet function in premenopausal women. Methods: Hematologic indices were assessed in a multicenter, retrospective cohort of 231 women repleted with intravenous iron. Pre- and postinfusion blood samples were then obtained from a prospective cohort of 13 women to analyze the effect of intravenous iron on hematologic parameters as well as platelet function with flow cytometry and platelet aggregation assays under physiologic shear. Results: Following iron replacement, anemia improved, and mean platelet counts decreased by 26.5 and 16.0 K/mm3 in the retrospective and prospective cohorts, respectively. Replacement reduced baseline platelet surface P-selectin levels while enhancing platelet secretory responses to agonists, including collagen-related peptide and ADP. Platelet adhesion and aggregation on collagen under physiologic shear also significantly increased following repletion. Conclusion: We find that intravenous iron improves anemia while restoring platelet counts and platelet secretory responses in premenopausal women with iron deficiency. Our results suggest that iron deficiency as well as iron replacement can have a range of effects on platelet production and function. Consequently, platelet reactivity profiles should be further examined in women and other groups with IDA where replacement offers a promising means to improve anemia as well as quality of life.

Factor XII plays a pathogenic role in organ failure and death in baboons challenged with Staphylococcus aureus.

Activation of coagulation factor (F) XI promotes multiorgan failure in rodent models of sepsis and in a baboon model of lethal systemic inflammation induced by infusion of heat-inactivated Staphylococcus aureus. Here we used the anticoagulant FXII-neutralizing antibody 5C12 to verify the mechanistic role of FXII in this baboon model. Compared with untreated control animals, repeated 5C12 administration before and at 8 and 24 hours after bacterial challenge prevented the dramatic increase in circulating complexes of contact system enzymes FXIIa, FXIa, and kallikrein with antithrombin or C1 inhibitor, and prevented cleavage and consumption of high-molecular-weight kininogen. Activation of several coagulation factors and fibrinolytic enzymes was also prevented. D-dimer levels exhibited a profound increase in the untreated animals but not in the treated animals. The antibody also blocked the increase in plasma biomarkers of inflammation and cell damage, including tumor necrosis factor, interleukin (IL)-1ß, IL-6, IL-8, IL-10, granulocyte-macrophage colony-stimulating factor, nucleosomes, and myeloperoxidase. Based on clinical presentation and circulating biomarkers, inhibition of FXII prevented fever, terminal hypotension, respiratory distress, and multiorgan failure. All animals receiving 5C12 had milder and transient clinical symptoms and were asymptomatic at day 7, whereas untreated control animals suffered irreversible multiorgan failure and had to be euthanized within 2 days after the bacterial challenge. This study confirms and extends our previous finding that at least 2 enzymes of the contact activation complex, FXIa and FXIIa, play critical roles in the development of an acute and terminal inflammatory response in baboons challenged with heat-inactivated S aureus.

Diagnosis and management of hereditary haemochromatosis.

Hereditary haemochromatosis, one of the most common genetic disorders in the United States, can produce systemic iron deposition leading to end-organ failure and death if untreated. The diagnosis of this condition can be challenging as elevated serum ferritin may be seen in a variety of conditions, including acute and chronic liver disease, a range of systemic inflammatory states, and both primary and secondary iron overload syndromes. Appropriate and timely diagnosis of haemochromatosis is paramount as simple interventions, such as phlebotomy, can prevent or reverse organ damage from iron overload. The recognition of other aetiologies of elevated ferritin is also vital to ensure that appropriate intervention is provided and phlebotomy only utilized in patients who require it. In this review, we summarize the existing data on the work up and management of hereditary haemochromatosis and present a practical algorithm for the diagnosis and management of this disease.

Chronic liver disease, thrombocytopenia and procedural bleeding risk; are novel thrombopoietin mimetics the solution?

Chronic liver disease (CLD) alters normal hemostatic and thrombotic systems via multiple mechanisms including reduced platelet function and number, leading to challenging peri-operative planning. Hepatic thrombopoietin (TPO) synthesis is reduced in CLD, leading to several recent randomized, placebo-controlled trials examining the utility of TPO-mimetics to increase platelet counts prior to surgery. While these trials do suggest that TPO-mimetics are efficacious at increasing platelet counts in patients with CLD and have led to several recent drug approvals in this space by the U.S. Food & Drug Administration, it remains unclear whether these results translate to the relevant clinical endpoint of reduced perioperative bleeding rate and severity. In this article, we review several recently-published, phase 3 trials on the TPO-mimetics eltrombopag, avatrombopag and lusutrombopag, and discuss the clinical significance of their results.

When to Stop Eculizumab in Complement-Mediated Thrombotic Microangiopathies.

The terminal complement-inhibitor eculizumab has dramatically changed the management of patients with atypical hemolytic uremic syndrome (aHUS), and has also shown promise for treating certain forms of secondary HUS (sHUS), including that caused by drugs and solid-organ/hematopoietic stem cell transplant. While effective, eculizumab is costly and inconvenient. In this review, we evaluate the literature on eculizumab cessation in these diseases to better inform clinicians who consider stopping therapy. Reported relapse rates in aHUS after stopping eculizumab are as high as 30%, suggesting indefinite therapy is reasonable and that patients who choose to stop should be closely monitored. In sHUS, relapse is rare, justifying short courses of eculizumab.

Management of Anticoagulation in Patients With Prostate Cancer Receiving Enzalutamide.

Enzalutamide, a novel, oral androgen receptor antagonist used for the treatment of metastatic, castration-resistant prostate cancer, has been shown to improve overall and progression-free survival, prolong time to initiation of chemotherapy, reduce skeletal-related events, and carry a favorable adverse effect profile. Metastatic prostate cancer is a disease of older men, a population with an increased incidence of medical comorbidities warranting anticoagulation. Prostate cancer itself, along with some of its therapies, is also prothrombotic. Enzalutamide interacts with several anticoagulants through various mechanisms, making their concurrent use clinically challenging. As such, complex decisions about anticoagulation in these patients are frequently encountered by treating physicians. In this review, we describe the potential interactions between enzalutamide and various anticoagulants, and suggest management paradigms based on the current body of knowledge for patients with atrial fibrillation, venous thromboembolism, and mechanical heart valves.