Targeting a higher plasma VWF level at time of delivery in pregnant individuals with von Willebrand disease: Outcomes at a single-institution cohort study.

INTRODUCTION: Guidelines on the management of pregnant individuals with von Willebrand disease (VWD) at the time of delivery recommend that von Willebrand factor (VWF) and factor VIII:C (FVIII:C) levels be ≥50% to prevent postpartum haemorrhage (PPH). Yet, high PPH rates persist despite these levels or with prophylactic factor replacement therapy to achieve these levels. AIMS: The current practice at our centre has been to target peak plasma VWF and FVIII:C levels of ≥100 IU/dL at time of delivery. The objective of this study was to describe obstetric outcomes in pregnant individuals with VWD who were managed at our centre. METHODS: Demographics and outcomes on pregnant individuals with VWD who delivered between January 2015 and April 2023 were collected. RESULTS: Forty-seven singleton deliveries (among 41 individuals) resulting in 46 live births and one foetal death were included. Twenty-one individuals had at least one prior birth by the start date of this study, of which 11 (52.4%) self-reported a history of PPH. Early PPH occurred in 12.8% (6/47) of deliveries. Two individuals required blood transfusion, of which one also had an unplanned hysterectomy and transfer to ICU. There were no thrombotic events reported. CONCLUSION: The strategy of targeting higher peak plasma VWF and FVIII:C levels (≥100 IU/dL) at the time of delivery may be effective in reducing the risk of delivery-associated bleeding complications in VWD patients. Yet, the rate of early PPH remains unsatisfactory compared to the non-VWD population.

How I treat cancer-associated anemia.

Despite increasing use of targeted therapies to treat cancer, anemia remains a common complication of cancer therapy. Physician concerns about the safety of intravenous (IV) iron products and erythropoiesis-stimulating agents (ESAs) have resulted in many patients with cancer receiving no or suboptimal anemia therapy. In this article, we present 4 patient cases that illustrate both common and complex clinical scenarios. We first present a review of erythropoiesis and then describe our approach to cancer-associated anemia by identifying the contributing causes before selecting specific treatments. We summarize clinical trial data affirming the safety and efficacy of currently available IV iron products used to treat cancer-associated anemia and illustrate how we use commonly available laboratory tests to assess iron status during routine patient management. We compare adverse event rates associated with IV iron vs red cell transfusion and discuss using first-line IV iron monotherapy to treat anemic patients with cancer, which decreases the need for ESAs. A possible mechanism behind ESA-induced tumor progression is discussed. Finally, we review the potential of novel therapies such as ascorbic acid, prolyl hydroxylase inhibitors, activin traps, hepcidin, and bone morphogenetic protein antagonists in treating cancer-associated anemia.

ALPK1 missense pathogenic variant in five families leads to ROSAH syndrome, an ocular multisystem autosomal dominant disorder.

PURPOSE: To identify the molecular cause in five unrelated families with a distinct autosomal dominant ocular systemic disorder we called ROSAH syndrome due to clinical features of retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and migraine headache. METHODS: Independent discovery exome and genome sequencing in families 1, 2, and 3, and confirmation in families 4 and 5. Expression of wild-type messenger RNA and protein in human and mouse tissues and cell lines. Ciliary assays in fibroblasts from affected and unaffected family members. RESULTS: We found the heterozygous missense variant in the ɑ-kinase gene, ALPK1, (c.710C>T, [p.Thr237Met]), segregated with disease in all five families. All patients shared the ROSAH phenotype with additional low-grade ocular inflammation, pancytopenia, recurrent infections, and mild renal impairment in some. ALPK1 was notably expressed in retina, retinal pigment epithelium, and optic nerve, with immunofluorescence indicating localization to the basal body of the connecting cilium of the photoreceptors, and presence in the sweat glands. Immunocytofluorescence revealed expression at the centrioles and spindle poles during metaphase, and at the base of the primary cilium. Affected family member fibroblasts demonstrated defective ciliogenesis. CONCLUSION: Heterozygosity for ALPK1, p.Thr237Met leads to ROSAH syndrome, an autosomal dominant ocular systemic disorder.

The D-dimer assay.

D-dimer is an indirect marker of fibrinolysis and fibrin turnover; this molecule exhibits unique properties as a biological marker of hemostatic abnormalities as well as an indicator of intravascular thrombosis. D-dimer is a soluble fibrin degradation product that results from the systematic degradation of vascular thrombi through the fibrinolytic mechanism. Because of this, the D-dimer serves as a valuable marker of activation of coagulation and fibrinolysis in a number of clinical scenarios. Most commonly, D-dimer has been extensively investigated for excluding the diagnosis of venous thromboembolism (VTE) and is used routinely for this indication. In addition, D-dimer has been evaluated for determining the optimal duration of anticoagulation in VTE patients, for diagnosing and monitoring disseminated intravascular coagulation, and for monitoring other conditions in which the patient is at high risk of bleeding or thrombosis. Limitations of the assay include D-dimer elevation in a constellation of clinical scenarios (age, pregnancy, and cancer) and lack of clinical standardization.

The Role of Intravenous Iron in the Treatment of Anemia Associated with Cancer and Chemotherapy.

Cancer-related anemia (CRA) is a commonly occurring problem for patients with cancer regardless of whether they are receiving treatment with chemotherapy or immunotherapy. It may result from one or more processes (decreased production, increased destruction, or increased loss of red blood cells, RBC). Perturbations in iron availability form the primary basis for anemia in many patients with cancer-related anemia. Functional iron deficiency (FID) anemia is a condition in which the patient has adequate or increased iron stores, but this iron pool is not available for erythropoiesis. Erythropoiesis-stimulating agents (ESAs) were the original treatment for FID; over time, however, if the supply of iron cannot keep pace with increased RBC synthesis driven by ESAs, FID may eventually lead to the lack or loss of ESA responsiveness. Subsequent clinical trials reported that intravenous (IV) iron could enhance the erythropoietic response to ESAs. This chapter reviews the pathogenesis of FID and summarizes the literature on the treatment of cancer- and chemotherapy-induced anemia. Clinical trials using IV iron with or without ESAs are reviewed in addition to the currently available IV iron products. The consensus conclusions from these trials, as well as guideline recommendations, support the use of IV iron in these patients to enhance ESA responsiveness, decrease ESA dosage, and reduce RBC transfusions. Little data have been published on the long-term safety of IV iron or its impact on tumor growth. This paper also briefly explores novel approaches for the treatment of FID anemia, which has relevance in treating not only cancer patients but also patients with benign inflammatory disorders.

Dynamic dosing of romiplostim in patients with immune thrombocytopenia purpura: Two case reports.

Romiplostim is a thrombopoietin receptor agonist approved for the treatment of immune thrombocytopenia purpura. When following FDA-approved romiplostim prescribing recommendations to withhold treatment for platelet counts above 400k/µL, some patients exhibit a precipitous decline in their platelet count potentially causing patient harm. We present two cases where stable platelet counts were achieved only through persistent weekly dosing of romiplostim despite platelet counts above 400k/µL on the day of administration. Therefore, continuous weekly dosing of romiplostim despite platelet count being above 400k/µL combined with twice weekly vigilant monitoring is an alternative method of romiplostim dosing that mitigates severe fluctuations in platelets. We also discuss important details, postulated mechanisms, and evidence-based mitigation strategies.

siRNA-knockdown of ADAMTS-13 modulates endothelial cell angiogenesis.

ADAMTS-13, a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13, is a zinc-containing metalloprotease that cleaves von Willebrand factor (vWf). Previous publications by our laboratory have shown that ADAMTS-13 may also be involved in angiogenesis. For this study, we report the successful transient knockdown of endogenous ADAMTS-13 in human umbilical vein endothelial cells (HUVEC) via siRNA and the effects of reduced endogenous ADAMTS-13 on HUVEC angiogenesis functions. 15nM of ADAMTS-13 siRNA reduced HUVEC ADAMTS-13 protein levels by 90% after 24h incubation, whereas control siRNA did not affect endogenous ADAMTS-13 levels. Furthermore, this transfection did not affect the HUVEC endogenous protein level of ADAMTS-1, a related family member of ADAMTS-13 indicating the specificity of the siRNA. Transfection of HUVEC with 15nM of ADAMTS-13 siRNA resulted in a 21% decrease in proliferation after 24h incubation. The effects of ADAMTS-13 knockdown on migration of HUVEC across a scratch wound were also evaluated. 24h after transfection with control siRNA, there was increased cell migration across the scratch wound. This dramatic migration did not occur with ADAMTS-13 knockdown cells. Decreased protein levels of endogenous ADAMTS-13 also affected angiogenesis as measured by endothelial cell tube formation using a Matrigel matrix method. The tube lengths, sizes and junction numbers of the ADAMTS-13 knockdown cells were all significantly lower compared to control cells by about 40%. The protein level of vascular endothelial growth factor (VEGF), a well-known regulator of angiogenesis, was significantly decreased by 45% upon knockdown of ADAMTS-13. Moreover, activity of the AKT pathway, one of the VEGF angiogenesis downstream signaling pathways was down-regulated by ADAMTS-13 siRNA. These data indicate that in cultured endothelial cells, one role of endogenous ADAMTS-13 is regulation of angiogenesis, mediated through VEGF and AKT signaling pathway. Overall, our data suggest an additional model of endogenous ADAMTS-13 functionality, beyond that of cleaving von Willebrand factor.

ADAMTS13 and its variants promote angiogenesis via upregulation of VEGF and VEGFR2.

Severe plasma ADAMTS13 deficiency results in the clinical disorder thrombotic thrombocytopenic purpura. However, other potential pathophysiological roles of ADAMTS13 in endothelial cell biology remain unexplored. The goals of this study were to understand the angiogenic pathways ADAMTS13 activates and to identify the important structural components of ADAMTS13 that stimulate angiogenesis. Incubation of human umbilical vein endothelial cells (HUVEC) with 150 ng/mL (1 nM) of recombinant human ADAMTS13 induced VEGF expression by 53 % and increased VEGF mRNA by over sixfold, both within 10 min; the measured VEGF levels steadily decreased over 2 h, as shown by Western blot and ELISA. Phosphorylation of VEGFR2 was significantly enhanced in HUVEC after incubation with ADAMTS13 (1 nM). Structure-function analysis showed that an ADAMTS13 variant containing thrombospondin type 1 (TSP1) 2-8 repeats (TSP1 2-8), TSP1 2-8 plus CUB domains (TSP1 2-8 plus CUB), or TSP1 5-8 repeats plus CUB domains (TSP1 5-8 plus CUB) increased HUVEC proliferation by 41-54 % as compared to the EBM-2 controls. Chemotaxis assays further demonstrated that the TSP1 domains of ADAMTS13 increased HUVEC migration by 2.65-fold. Incubation of HUVEC with both ADAMTS13 variants containing TSP1 repeats and anti-VEGF IgG abrogated the enhanced effect of ADAMTS13 on proliferation, migration, and VEGFR2 phosphorylation. In conclusion, ADAMTS13-induced endothelial cell angiogenesis occurs via the upregulation of VEGF and phosphorylation of VEGFR2. This angiogenic activity depends on the C-terminal TSP1 repeats of ADAMTS13.

Treatment strategies for myeloid growth factors and intravenous iron: when, what, and how?

Myeloid growth factors can reduce the risk of chemotherapy-induced neutropenia (CIN) and thus impact the survival of patients with cancer. Patients should be assessed for risk, taking into consideration patient-related risk factors and chemotherapy regimens. Patients stratified as having at least a 20% risk for CIN should be considered for prophylactic growth factors. The NCCN Guidelines for Myeloid Growth Factors provide category 1 recommendations for the daily use of filgrastim, tbo-filgrastim, and pegfilgrastim. Cancer-related anemia can be treated with erythropoiesis-stimulating agents, red blood cell transfusion, or intravenous iron.

Diagnosis and treatment of cancer-related anemia.

Cancer-related anemia (CRA) is due to multiple etiologies, including chemotherapy-induced myelosuppression, blood loss, functional iron deficiency, erythropoietin deficiency due to renal disease, marrow involvement with tumor as well as other factors. The most common treatment options for CRA include iron therapy, erythropoietic-stimulating agents (ESAs), and red cell transfusion. Safety concerns as well as restrictions and reimbursement issues surrounding ESA therapy for CRA have resulted in suboptimal treatment. Similarly, many clinicians are not familiar or comfortable using intravenous iron products to treat functional iron deficiency associated with CRA. This article summarizes our approach to treating CRA and discusses commonly encountered clinical scenarios for which current clinical guidelines do not apply.

Update on iron supplementation in patients with cancer-related anemia.

INTRODUCTION: Numerous clinical trials affirm the efficacy and safety of IV iron to treat cancer-related anemia (CRA). Nonetheless, evaluation and treatment of CRA remains suboptimal. AREAS COVERED: This review summarizes CRA therapy with a focus on iron deficiency and its treatment. The literature search was conducted using the National Library of Medicine (PubMed) database from 2004 to 2024. Topics reviewed include CRA pathophysiology, laboratory diagnosis of iron deficiency, a summary of clinical trial results using IV iron to treat CRA, and safety aspects. EXPERT OPINION: Despite overwhelming positive efficacy and safety data, IV iron remains underutilized to treat CRA. This is likely due to persistent (unfounded) concerns about IV iron safety and lack of physician awareness of newer clinical trial data. This leads to poor patient quality of life and patient exposure to anemia treatments that have greater safety risks than IV iron. Solutions to this problem include increased educational efforts and considering alternative treatment models in which other providers separately manage CRA. The recent availability of new oral iron therapy products that are effective in treating anemia of inflammation has the potential to dramatically simplify the treatment of CRA.

How I manage patients with acquired haemophilia A.

Acquired haemophilia A (AHA) is a potentially life-threatening bleeding disorder occurring in patients without a previous personal or family history of bleeding. Development of immune-mediated autoantibodies against coagulation factor VIII is associated with a wide range of clinical disorders including pregnancy, autoimmune disorders, malignancy, or with no apparent disease. There exists great potential for morbidity and mortality related to acute and recurrent bleeding episodes, making prompt diagnosis and treatment necessary. The two primary goals of treatment focus on cessation of bleeding and eradication of the acquired factor VIII inhibitor. No randomized clinical trials have been conducted regarding treatment, so expert clinical opinion guides therapeutic intervention. This current report provides a profile of patient characteristics, an algorithm for diagnosis, and outlines treatment recommendations based upon current guidelines and clinical experience. As first-line interventions for acute bleeding and inhibitor eradication are generally accepted, we will emphasize discussion of second-line therapeutic options.

Antithrombin Therapy: Current State and Future Outlook.

Antithrombin (AT) is a natural anticoagulant pivotal in inactivating serine protease enzymes in the coagulation cascade, making it a potent inhibitor of blood clot formation. AT also possesses anti-inflammatory properties by influencing anticoagulation and directly interacting with endothelial cells. Hereditary AT deficiency is one of the most severe inherited thrombophilias, with up to 85% lifetime risk of venous thromboembolism. Acquired AT deficiency arises during heparin therapy or states of hypercoagulability like sepsis and premature infancy. Optimization of AT levels in individuals with AT deficiency is an important treatment consideration, particularly during high-risk situations such as surgery, trauma, pregnancy, and postpartum. Here, we integrate the existing evidence surrounding the approved uses of AT therapy, as well as potential additional patient populations where AT therapy has been considered by the medical community, including any available consensus statements and guidelines. We also describe current knowledge regarding cost-effectiveness of AT concentrate in different contexts. Future work should seek to identify specific patient populations for whom targeted AT therapy is likely to provide the strongest clinical benefit.

Prolonged Exposure to Caplacizumab as Rescue Therapy in Refractory Immune Thrombotic Thrombocytopenic Purpura.

We describe a case of refractory thrombotic thrombocytopenic purpura (7 lines of therapy) in which caplacizumab was used over a 6-month period as rescue therapy. Caplacizumab maintained the patient in clinical remission until successful immunosuppression was achieved resulting in normal ADAMTS13 levels. This case illustrates the utility of caplacizumab therapy in treating refractory TTP.

ADAMTS13 promotes angiogenesis and modulates VEGF-induced angiogenesis.

Plasma ADAMTS13 deficiency results in the clinical disorder thrombotic thrombocytopenic purpura. However, other potential pathophysiological roles of ADAMTS13 in endothelial cell biology remain unexplored. To assess the possible role of ADAMTS13 and its interactions with VEGF-mediated angiogenesis, the effects of ADAMTS13 on human umbilical vein endothelial cell (HUVEC) were studied in Matrigel tube formation, proliferation, cell migration, and scratch wound assays. Treatment of endothelial cells with exogenous recombinant full-length ADAMTS13 alone promoted angiogenesis in a dose-dependent manner. HUVEC incubated with 200 ng/mL ADAMTS13 (1.4 nM) resulted in a 65% increase in cell tube formation when compared to the EBM-2 control. HUVEC treated with 30 ng/mL ADAMTS13 (204.1 pM) resulted in an 83% increase in proliferation in a visual counting assay, whereas HUVEC treated with 10 ng/mL ADAMTS13 (68.0 pM) yielded a 295% increase in EC migration in a Boyden chamber assay. In contrast, ADAMTS13 inhibited VEGF-induced angiogenesis in a dose-dependent manner, with 200ng/mL inhibiting tube formation by 35%. HUVEC co-incubated with ADAMTS13 and an antibody to the ADAMTS13 thrombospondin domains 5-7 reversed the inhibition of tube formation. HUVEC treated with 30 ng/mL ADAMTS13 and 6.2 ng/mL (323.0 pM) VEGF proliferated 40% slower than the VEGF control after 24 h of incubation as measured by visual counting assay. Treatment of HUVEC with 6.2 ng/mL VEGF and 10 ng/mL ADAMTS13 inhibited cell migration by 48%, compared to the VEGF control. Substitution of ADAMTS13 with truncated ADAMTS13 (deletion of C-terminal TSP1 domain) did not significantly increase angiogenesis or suppress VEGF-induced angiogenesis, suggesting that the TSP1 domain is involved in ADAMTS13 angiogenic activities. Co-immunoprecipitation experiments provided further evidence that ADAMTS13 binds to VEGF via its TSP1 domain.

An inherited disorder with splenomegaly, cytopenias, and vision loss.

We describe a novel inherited disorder consisting of idiopathic massive splenomegaly, cytopenias, anhidrosis, chronic optic nerve edema, and vision loss. This disorder involves three affected patients in a single non-consanguineous Caucasian family, a mother and two daughters, who are half-sisters. All three patients have had splenectomies; histopathology revealed congestion of the red pulp, but otherwise no abnormalities. Electron microscopic studies of splenic tissue showed no evidence for a storage disorder or other ultrastructural abnormality. Two of the three patients had bone marrow examinations that were non-diagnostic. All three patients developed progressive vision loss such that the two oldest patients are now blind, possibly due to a cone-rod dystrophy. Characteristics of vision loss in this family include early chronic optic nerve edema, and progressive vision loss, particularly central and color vision. Despite numerous medical and ophthalmic evaluations, no diagnosis has been discovered.