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C3G is a Rap1 GEF that plays a pivotal role in platelet-mediated processes such as angiogenesis, tumor growth, and metastasis by modulating the platelet secretome. Here, we explore the mechanisms through which C3G governs platelet secretion. For this, we utilized animal models featuring either overexpression or deletion of C3G in platelets, as well as PC12 cell clones expressing C3G mutants. We found that C3G specifically regulates α-granule secretion via PKCδ, but it does not affect δ-granules or lysosomes. C3G activated RalA through a GEF-dependent mechanism, facilitating vesicle docking, while interfering with the formation of the trans-SNARE complex, thereby restricting vesicle fusion. Furthermore, C3G promotes the formation of lamellipodia during platelet spreading on specific substrates by enhancing actin polymerization via Src and Rac1-Arp2/3 pathways, but not Rap1. Consequently, C3G deletion in platelets favored kiss-and-run exocytosis. C3G also controlled granule secretion in PC12 cells, including pore formation. Additionally, C3G-deficient platelets exhibited reduced phosphatidylserine exposure, resulting in decreased thrombin generation, which along with defective actin polymerization and spreading, led to impaired clot retraction. In summary, platelet C3G plays a dual role by facilitating platelet spreading and clot retraction through the promotion of outside-in signaling while concurrently downregulating α-granule secretion by restricting granule fusion., (© 2024. The Author(s).)

Acquired hemophilia A (AHA) is a rare bleeding disorder caused by the presence of autoantibodies against factor VIII (FVIII). As with other autoimmune diseases, its etiology is complex and its genetic basis is unknown. The aim of this study was to identify the immunogenetic background that predisposes individuals to AHA. HLA and KIR gene clusters, as well as KLRK1 , were sequenced using next-generation sequencing in 49 AHA patients. Associations between candidate genes involved in innate and adaptive immune responses and AHA were addressed by comparing the alleles, genotypes, haplotypes, and gene frequencies in the AHA cohort with those in the donors' samples or Spanish population cohort. Two genes of the HLA cluster, as well as rs1049174 in KLRK1 , which tags the natural killer (NK) cytotoxic activity haplotype, were found to be linked to AHA. Specifically, A*03:01 ( p = 0.024; odds ratio (OR) = 0.26[0.06-0.85]) and DRB1*13:03 ( p = 6.8 × 10 3 , OR = 7.56[1.64-51.40]), as well as rs1049174 ( p = 0.012), were significantly associated with AHA. In addition, two AHA patients were found to carry one copy each of the low-frequency allele DQB1*03:09 ( n allele = 2, 2.04%), which was completely absent in the donors. To the best of our knowledge, this is the first time that the involvement of these specific alleles in the predisposition to AHA has been proposed. Further molecular and functional studies will be needed to unravel their specific contributions. We believe our findings expand the current knowledge on the genetic factors involved in susceptibility to AHA, which will contribute to improving the diagnosis and prognosis of AHA patients.

Protein glycosylation, including sialylation, involves complex and frequent post-translational modifications, which play a critical role in different biological processes. The conjugation of carbohydrate residues to specific molecules and receptors is critical for normal hematopoiesis, as it favors the proliferation and clearance of hematopoietic precursors. Through this mechanism, the circulating platelet count is controlled by the appropriate platelet production by megakaryocytes, and the kinetics of platelet clearance. Platelets have a half-life in blood ranging from 8 to 11 days, after which they lose the final sialic acid and are recognized by receptors in the liver and eliminated from the bloodstream. This favors the transduction of thrombopoietin, which induces megakaryopoiesis to produce new platelets. More than two hundred enzymes are responsible for proper glycosylation and sialylation. In recent years, novel disorders of glycosylation caused by molecular variants in multiple genes have been described. The phenotype of the patients with genetic alterations in GNE, SLC35A1, GALE and B4GALT is consistent with syndromic manifestations, severe inherited thrombocytopenia, and hemorrhagic complications.

Glycosylation is recognized as a key process for proper megakaryopoiesis and platelet formation. The enzyme uridine diphosphate (UDP)-galactose-4-epimerase, encoded by GALE, is involved in galactose metabolism and protein glycosylation. Here, we studied 3 patients from 2 unrelated families who showed lifelong severe thrombocytopenia, bleeding diathesis, mental retardation, mitral valve prolapse, and jaundice. Whole-exome sequencing revealed 4 variants that affect GALE, 3 of those previously unreported (Pedigree A, p.Lys78ValfsX32 and p.Thr150Met; Pedigree B, p.Val128Met; and p.Leu223Pro). Platelet phenotype analysis showed giant and/or grey platelets, impaired platelet aggregation, and severely reduced alpha and dense granule secretion. Enzymatic activity of the UDP-galactose-4-epimerase enzyme was severely decreased in all patients. Immunoblotting of platelet lysates revealed reduced GALE protein levels, a significant decrease in N-acetyl-lactosamine (LacNAc), showing a hypoglycosylation pattern, reduced surface expression of gylcoprotein Ibα-IX-V (GPIbα-IX-V) complex and mature β1 integrin, and increased apoptosis. In vitro studies performed with patients-derived megakaryocytes showed normal ploidy and maturation but decreased proplatelet formation because of the impaired glycosylation of the GPIbα and β1 integrin, and reduced externalization to megakaryocyte and platelet membranes. Altered distribution of filamin A and actin and delocalization of the von Willebrand factor were also shown. Overall, this study expands our knowledge of GALE-related thrombocytopenia and emphasizes the critical role of GALE in the physiological glycosylation of key proteins involved in platelet production and function., (© 2023 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Prophylaxis to prevent bleeding is highly recommended for hemophilia patients. The development of new drugs and tools for modeling personalized prophylaxis provides the means for people with hemophilia to lead active lives with a quality of life comparable to that of nonhemophilic individuals. The choice of regimens must be made on a highly individual basis. Unfortunately, reference guides neither always concur in their recommendations nor provide directions to cover all possible scenarios. In this review, a group of experts identify the significant limitations and unmet needs of prophylaxis, taking advantage of their clinical experience in the disease, and supported by a rigorous literature update. To perform a more systematic and comprehensive search for gaps, the main cornerstones that influence decisions regarding prophylactic patterns were first identified. Bleeding phenotype, joint status, physical activity, pharmacokinetics/medication properties, and adherence to treatment were considered as the primary mainstays that should allow physicians guiding prophylaxis to secure the best outcomes. Several challenges identified within each of these topics require urgent attention and agreement. The scores to assess severity of bleeding are not reliable, and lead to no consensus definition of severe bleeding phenotype. The joint status is to be redefined in light of new, more efficient treatments with an agreement to establish one scale as the unique reference for joint health. Further discussion is needed to establish the appropriateness of high-intensity physical activities according to patient profiles, especially because sustaining trough factor levels within the safe range is not always warranted for long periods. Importantly, many physicians do not benefit from the advantages provided by the programs based on population pharmacokinetic models to guide individualized prophylaxis through more efficient and cost-saving strategies. Finally, ensuring correct adherence to long-term treatments may be time-consuming for practitioners, who often have to encourage patients and review complex questionnaires. In summary, we identify five cornerstones that influence prophylaxis and discuss the main conflicting concerns that challenge the proper long-term management of hemophilia. A consensus exercise is warranted to provide reliable guidelines and maximize benefit from recently developed tools that should notably improve patients' quality of life., Competing Interests: Conflict of Interest None declared., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. ( https://creativecommons.org/licenses/by-nc-nd/4.0/ ).)

Primary immune thrombocytopenia (ITP) is an autoimmune disorder that causes low platelet counts and subsequent bleeding risk. Although current corticosteroid-based ITP therapies are able to improve platelet counts, up to 70% of subjects with an ITP diagnosis do not achieve a sustained clinical response in the absence of treatment, thus requiring a second-line therapy option as well as additional care to prevent bleeding. Less than 40% of patients treated with thrombopoietin analogs, 60% of those treated with splenectomy, and 20% or fewer of those treated with rituximab or fostamatinib reach sustained remission in the absence of treatment. Therefore, optimizing therapeutic options for ITP management is mandatory. The pathophysiology of ITP is complex and involves several mechanisms that are apparently unrelated. These include the clearance of autoantibody-coated platelets by splenic macrophages or by the complement system, hepatic desialylated platelet destruction, and the inhibition of platelet production from megakaryocytes. The number of pathways involved may challenge treatment, but, at the same time, offer the possibility of unveiling a variety of new targets as the knowledge of the involved mechanisms progresses. The aim of this work, after revising the limitations of the current treatments, is to perform a thorough review of the mechanisms of action, pharmacokinetics/pharmacodynamics, efficacy, safety, and development stage of the novel ITP therapies under investigation. Hopefully, several of the options included herein may allow us to personalize ITP management according to the needs of each patient in the near future.

Purpose: To assess whether subjects with Philadelphia negative myeloproliferative neoplasms (Ph-MPNs) show differences in the presence of vascular, cardiac or renal target organ damage (TOD) and other vascular function parameters as compared to individuals without this condition., Methods: An observational study was conducted. Fifty-seven subjects diagnosed with Ph-MPNs used as cases and 114 subjects without Ph-MPNs as controls. We matched the subjects with and without Ph-MPNs using the propensity scores in a 1:2 ratio using the variables gender, type 2 diabetes mellitus, high blood pressure, hyperlipidaemia and smoking. Vascular, cardiac and renal TOD were established according to the criteria of the European Society of Hypertension and Cardiology guidelines. Arterial stiffness was also assessed using the cardio-ankle vascular index (CAVI)., Results: Mean age was 63.50±11.70 and 62.90±8.32 years in subjects with and without Ph-MPNs, 32 females (56%) in the first group and 62 (54%) in the second. Subjects with Ph-MPNs have a higher percentage of carotid injury than subjects without Ph-MPNs (35.1% vs. 21.1%) and higher albumin/creatinine ratio. In the logistic regression analysis, subjects with Ph-MPNs had an OR=2.382 (IC95% 1.066-5.323) for carotid injury versus those without haematological disease., Conclusions: Subjects with Ph-MPNs have twice the risk of by carotid injury than those without haematological disease., (Copyright © 2021 Elsevier España, S.L.U. All rights reserved.)

Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal-dominant genetic disorder involving defects in two predominant genes known as endoglin ( ENG ; HHT-1) and activin receptor-like kinase 1 ( ACVRL1/ALK1 ; HHT-2). It is characterized by mucocutaneous telangiectases that, due to their fragility, frequently break causing recurrent epistaxis and gastrointestinal bleeding. Because of the severity of hemorrhages, the study of the hemostasis involved in these vascular ruptures is critical to find therapies for this disease. Our results demonstrate that HHT patients with high bleeding, as determined by a high Epistaxis Severity Score (ESS), do not have prolonged clotting times or alterations in clotting factors. Considering that coagulation is only one of the processes involved in hemostasis, the main objective of this study was to investigate the overall mechanisms of hemostasis in HHT-1 ( Eng +/- ) and HHT-2 ( Alk1 +/- ) mouse models, which do not show HHT vascular phenotypes in the meaning of spontaneous bleeding. In Eng +/- mice, the results of in vivo and in vitro assays suggest deficient platelet-endothelium interactions that impair a robust and stable thrombus formation. Consequently, the thrombus could be torn off and dragged by the mechanical force exerted by the bloodstream, leading to the reappearance of hemorrhages. In Alk1 +/- mice, an overactivation of the fibrinolysis system was observed. These results support the idea that endoglin and Alk1 haploinsufficiency leads to a common phenotype of impaired hemostasis, but through different mechanisms. This contribution opens new therapeutic approaches to HHT patients' epistaxis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Egido-Turrión, Rossi, Ollauri-Ibáñez, Pérez-García, Sevilla, Bastida, González-Porras, Rodríguez-Barbero, Bernabeu, Lopez-Novoa and Pericacho.)

Background: Rare inherited thrombocytopenias are caused by alterations in genes involved in megakaryopoiesis, thrombopoiesis and/or platelet release. Diagnosis is challenging due to poor specificity of platelet laboratory assays, large numbers of culprit genes, and difficult assessment of the pathogenicity of novel variants., Objectives: To characterize the clinical and laboratory phenotype, and identifying the underlying molecular alteration, in a pedigree with thrombocytopenia of uncertain etiology., Patients/methods: Index case was enrolled in our Spanish multicentric project of inherited platelet disorders due to lifelong thrombocytopenia and bleeding. Bleeding score was recorded by ISTH-BAT. Laboratory phenotyping consisted of blood cells count, blood film, platelet aggregation and flow cytometric analysis. Genotyping was made by whole-exome sequencing (WES). Cytoskeleton proteins were analyzed in resting/spreading platelets by immunofluorescence and immunoblotting., Results: Five family members displayed lifelong mild thrombocytopenia with a high number of enlarged platelets in blood film, and mild bleeding tendency. Patient's platelets showed normal aggregation and granule secretion response to several agonists. WES revealed a novel nonsense variant (c.322C>T; p.Gln108*) in TPM4 (NM_003290.3), the gene encoding for tropomyosin-4 (TPM4). This variant led to impairment of platelet spreading capacity after stimulation with TRAP-6 and CRP, delocalization of TPM4 in activated platelets, and significantly reduced TPM4 levels in platelet lysates. Moreover, the index case displayed up-regulation of TPM2 and TPM3 mRNA levels., Conclusions: This study identifies a novel TPM4 nonsense variant segregating with macrothrombocytopenia and impaired platelet cytoskeletal remodeling and spreading. These findings support the relevant role of TPM4 in thrombopoiesis and further expand our knowledge of TPM4-related thrombocytopenia., (© 2022 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis.)

Background: Open surgical repair (OSR) and endovascular aneurysm repair (EVAR) surgery are alternative treatments for infrarenal abdominal aortic aneurysm (IRAAA)., Objectives: To compare OSR and EVAR for the treatment of IRAAA., Methods: 119 patients with IRAAA were electively operated by the same surgeon between January 1, 2006 and December 31, 2015, following selection for OSR or EVAR according to surgical risk. Complications, reinterventions, failures, and early and late mortality were analyzed., Results: 63 OSR and 56 EVAR patients were analyzed. They were similar in terms of age (70 years), gender (92% men), and average diameter of IRAAA (6.5 cm), but with different comorbidities, surgical risk, and anatomy. EVAR was better than OSR regarding time in the operating theatre (177.5 vs. 233.3 minutes), need for transfusion (25 vs. 73%), and length of stay in ICU (1.3 vs. 3.3 days) and hospital (8.1 vs. 11.1 days). OSR allowed more associated procedures to be conducted simultaneously (19.0 vs. 1.8%). There were no significant differences between the groups with respect to complications (25.4 vs. 25.1%), reinterventions (3.2 vs. 5.2%), or early mortality (1.6 vs. 0%). During follow-up, OSR was associated with fewer revisions (3.13 vs. 4.21), angio-CTs (0.22 vs. 3.23), complications (6.4 vs. 37.5%), reinterventions (3.2 vs. 23.2%), and failures (1.6 vs. 10.7%), and had better survival (78.2 vs. 63.2%)., Conclusions: Correct selection of patients achieves excellent results because it avoids OSR in patients at high risk and avoids EVAR in patients with high anatomical complexity, achieving similar results in the perioperative period, but better results for OSR over the course of follow-up., Competing Interests: Conflicts of interest: No conflicts of interest declared concerning the publication of this article., (Copyright© 2021 The authors.)

Objective: To identify potential markers at admission predicting the need for critical care in patients with COVID-19 pneumonia., Material and Methods: An approved, observational, retrospective study was conducted between March 15 to April 15, 2020. 150 adult patients aged less than 75 with Charlson comorbidity index ≤6 diagnosed with COVID-19 pneumonia were included. Seventy-five patients were randomly selected from those admitted to the critical care units (critical care group [CG]) and seventy-five hospitalized patients who did not require critical care (non-critical care group [nCG]) represent the control group. One additional cohort of hospitalized patients with COVID-19 were used to validate the score., Measurements and Main Results: Multivariable regression showed increasing odds of in-hospital critical care associated with increased C-reactive protein (CRP) (odds ratio 1.052 [1.009-1.101]; P = 0.0043) and higher Sequential Organ Failure Assessment (SOFA) score (1.968 [1.389-2.590]; P < 0.0001), both at the time of hospital admission. The AUC-ROC for the combined model was 0.83 (0.76-0.90) (vs AUC-ROC SOFA P < 0.05). The AUC-ROC for the validation cohort was 0.89 (0.82-0.95) (P > 0.05 vs AUC-ROC development)., Conclusion: Patients COVID-19 presenting at admission SOFA score ≥ 2 combined with CRP ≥ 9.1 mg/mL could be at high risk to require critical care., (Copyright © 2021 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.)

RUNX1 -related disorder ( RUNX1 -RD) is caused by germline variants affecting the RUNX1 gene. This rare, heterogeneous disorder has no specific clinical or laboratory phenotype, making genetic diagnosis necessary. Although international recommendations have been established to classify the pathogenicity of variants, identifying the causative alteration remains a challenge in RUNX1 -RD. Murine models may be useful not only for definitively settling the controversy about the pathogenicity of certain RUNX1 variants, but also for elucidating the mechanisms of molecular pathogenesis. Therefore, we developed a knock-in murine model, using the CRISPR/Cas9 system, carrying the RUNX1 p.Leu43Ser variant (mimicking human p.Leu56Ser) to study its pathogenic potential and mechanisms of platelet dysfunction. A total number of 75 mice were generated; 25 per genotype (RUNX1 WT/WT , RUNX1 WT/L43S , and RUNX1 L43S/L43S ). Platelet phenotype was assessed by flow cytometry and confocal microscopy. On average, RUNX1 L43S/L43S and RUNX1 WT/L43S mice had a significantly longer tail-bleeding time than RUNX1 WT/WT mice, indicating the variant's involvement in hemostasis. However, only homozygous mice displayed mild thrombocytopenia. RUNX1 L43S/L43S and RUNX1 WT/L43S displayed impaired agonist-induced spreading and α-granule release, with no differences in δ-granule secretion. Levels of integrin α IIb β 3 activation, fibrinogen binding, and aggregation were significantly lower in platelets from RUNX1 L43S/L43S and RUNX1 WT/L43S using phorbol 12-myristate 13-acetate (PMA), adenosine diphosphate (ADP), and high thrombin doses. Lower levels of PKC phosphorylation in RUNX1 L43S/L43S and RUNX1 WT/L43S suggested that the PKC-signaling pathway was impaired. Overall, we demonstrated the deleterious effect of the RUNX1 p.Leu56Ser variant in mice via the impairment of integrin α IIb β 3 activation, aggregation, α-granule secretion, and platelet spreading, mimicking the phenotype associated with RUNX1 variants in the clinical setting., Competing Interests: None declared., (Thieme. All rights reserved.)

Eltrombopag is a thrombopoietin receptor (MPL) agonist approved for the treatment of primary immune thrombocytopenia (ITP). Recent evidence shows that some patients may sustain platelet counts following eltrombopag discontinuation. The systemic immunomodulatory response that resolves ITP in some patients could result from an increase in platelet mass, caused either by the direct action of eltrombopag on megakaryocytes through MPL stimulation, or potential MPL-independent actions on other cell types. To uncover the possible mechanisms of action of eltrombopag, in silico analyses were performed, including a systems biology-based approach, a therapeutic performance mapping system, and structural analyses. Through manual curation of the available bibliography, 56 key proteins were identified and integrated into the ITP interactome analysis. Mathematical models (94.92% mean accuracy) were obtained to elucidate potential MPL-dependent pathways in non-megakaryocytic cell subtypes. In addition to the effects on megakaryocytes and platelet numbers, the results were consistent with MPL-mediated effects on other cells, which could involve interferon-gamma, transforming growth factor-beta, peroxisome proliferator-activated receptor-gamma, and forkhead box protein P3 pathways. Structural analyses indicated that effects on three apoptosis-related proteins (BCL2L1, BCL2, BAX) from the Bcl-2 family may be off-target effects of eltrombopag. In conclusion, this study proposes new hypotheses regarding the immunomodulatory functions of eltrombopag in patients with ITP.

Platelets play a major role in hemostasis as ppwell as in many other physiological and pathological processes. Accordingly, production of about 10 11 platelet per day as well as appropriate survival and functions are life essential events. Inherited platelet disorders (IPDs), affecting either platelet count or platelet functions, comprise a heterogenous group of about sixty rare diseases caused by molecular anomalies in many culprit genes. Their clinical relevance is highly variable according to the specific disease and even within the same type, ranging from almost negligible to life-threatening. Mucocutaneous bleeding diathesis (epistaxis, gum bleeding, purpura, menorrhagia), but also multisystemic disorders and/or malignancy comprise the clinical spectrum of IPDs. The early and accurate diagnosis of IPDs and a close patient medical follow-up is of great importance. A genotype-phenotype relationship in many IPDs makes a molecular diagnosis especially relevant to proper clinical management. Genetic diagnosis of IPDs has been greatly facilitated by the introduction of high throughput sequencing (HTS) techniques into mainstream investigation practice in these diseases. However, there are still unsolved ethical concerns on general genetic investigations. Patients should be informed and comprehend the potential implications of their genetic analysis. Unlike the progress in diagnosis, there have been no major advances in the clinical management of IPDs. Educational and preventive measures, few hemostatic drugs, platelet transfusions, thrombopoietin receptor agonists, and in life-threatening IPDs, allogeneic hematopoietic stem cell transplantation are therapeutic possibilities. Gene therapy may be a future option. Regular follow-up by a specialized hematology service with multidisciplinary support especially for syndromic IPDs is mandatory.

Background: Abdominal aortic aneurysm and acute appendicitis occur relatively frequently in elderly patients. However, the co-occurrence of the two pathologies is very rare and serious., Case Presentation: We present the case of an elderly Caucasian patient who was aware of having an abdominal aortic aneurysm but refused treatment and was subsequently admitted to the hospital's emergency department with acute abdominal symptoms. A computed tomography scan raised the possibility of complication due to the characteristics of the aneurysm. The patient then agreed to emergency surgery. Laparotomy revealed the existence of an acute perforated appendicitis with a significant abscess in the right iliac fossa and an uncomplicated aneurysm. Appendectomy was performed and the abscess drained. The postoperative period passed without complications, and the patient again refused surgery for the aneurysm, which due to its anatomical characteristics was not a candidate for standard endovascular treatment., Conclusions: In light of this experience, we review the literature about the relationship between abdominal aortic aneurysm and acute appendicitis.

Background: Carotid paragangliomas are rare tumors. They are usually unique, non-secreting, resectable, and benign. However, additional rare cases of complex tumors (bilateral, secretory, nonresectable, or malignant) complicate the management and final outcomes., Methods: Records of paragangliomas from our hospital are reviewed. Criteria defining complex paragangliomas have been previously defined. These are compared with those of the simple group., Results: Fifty patients, two groups: simple (n = 39) and complex (n = 11). The patients in the complex group were significantly younger (47.7 vs 63.8 years). Postoperative nerve complications (45.4% vs 6.3%) and mortality during follow-up (27.3% vs 0%) were significantly more common in the complex group. Vascular complications (0% vs 3.1%) and early mortality (0%) were similarly in both groups., Conclusions: Patients with complex carotid paragangliomas are heterogeneous. The former are younger, exhibit a high degree of diagnostic and therapeutic complexity, and have poorer morbidity and mortality. Surgical experience and interdisciplinary collaboration are essential., (© 2020 Wiley Periodicals LLC.)

In the last years, the use of thrombopoietin receptor agonists (TPO-RA), eltrombopag and romiplostim, has improved the management of immune thrombocytopenia (ITP). Moreover, eltrombopag is also active in patients with aplastic anemia and myelodysplastic syndrome. However, their mechanisms of action and signaling pathways still remain controversial. In order to gain insight into the mechanisms underlying eltrombopag therapy, a gene expression profile (GEP) analysis in patients treated with this drug was carried out. Fourteen patients with chronic ITP were studied by means of microarrays before and during eltrombopag treatment. Median age was 78 years (range, 35-87 years); median baseline platelet count was 14 × 10 9 /L (range, 2-68 × 10 9 /L). Ten patients responded to the therapy, two cases relapsed after an initial response and the remaining two were refractory to the therapy. Eltrombopag induced relevant changes in the hematopoiesis, platelet activation and degranulation, as well as in megakaryocyte differentiation, with overexpression of some transcription factors and the genes PPBP, ITGB3, ITGA2B, F13A1, F13A1, MYL9 and ITGA2B . In addition, GP1BA, PF4, ITGA2B, MYL9, HIST1H4H and HIST1H2BH , genes regulated by RUNX1 were also significantly enriched after eltrombopag therapy. Furthermore, in non-responder patients, an overexpression of Bcl-X gene and genes involved in erythropoiesis, such as SLC4A1 and SLC25A39 , was also observed. To conclude, overexpression in genes involved in megakaryopoiesis, platelet adhesion, degranulation and aggregation was observed in patients treated with eltrombopag. Moreover, an important role regarding heme metabolism was also present in non-responder patients.

Objective: Splenectomy, thrombopoietin receptor agonists and rituximab are  the second-line treatments for steroid-resistant adult primary immune  thrombocytopenia. The last two are becoming the most widely used treatments  to avoid splenectomy adverse effects and inconveniences. However, the choice  between rituximab and thrombopoietin receptor agonists is unclear. Therefore,  the treatment cost may be of particular interest to prioritize the therapy option.  Our aim is to determine the cost per responding-patient after 6 months of use of rituximab compared to thrombopoietin receptor agonists eltrombopag in the  treatment of chronic primary immune thrombocytopenia in the Spanish National  Health Service., Method: A 26-week decision tree model was developed to assess the cost of  treatment response of adult patients with chronic-refractory primary immune  thrombocytopenia to eltrombopag and rituximab from the perspective of the  Spanish National Health System. Effectiveness was obtained from the literature,  and cost was obtained from the official rates. Costs were expressed in € (2018).  Due to the short period of assessment, no discount rate was applied., Results: The average cost per patient after 6 months of treatment was slightly  higher for eltrombopag (€13,089.40) than for rituximab (€11,852.60). However, the greater response rate of eltrombopag decreases the bleeding costs, resulting in a 29% higher cost per responding-patient with rituximab (€18,964.15) than  for eltrombopag (€14,732.65). This result is consistent with the results of the 15 sensitivity analyses carried out where eltrombopag always represents a lower  cost per responding patient, except in the sensitivity analysis in which treatment with eltrombopag is performed at its maximum dose (75mg). Only in this case,  the cost per responder of eltrombopag is €48 more expensive than that of  rituximab. Likewise, the greatest difference in favor of eltrombopag occurs in the scenario that uses the minimum dose of this drug -25mg- (eltrombopag  €7,622.14 compared to €18,964.15 for rituximab). Thus, the cost per  responding patient is lower in eltrombopag even if a second cycle of retreatment with rituximab is not performed (€14,732.65 versus €15,298.61)., Conclusions: The treatment cost of rituximab, including monitoring and bleeding costs, is higher than eltrombopag, favoring the latter over  rituximab treatment., (Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.)

Acquired haemophilia A (AHA) is a rare autoimmune disorder caused by an autoantibody against any circulating coagulation factor, especially factor VIII (FVIII). The lack of awareness of this condition suggests that diagnosis is a challenge and usually delayed, which leads to suboptimal treatment. Consequently, early diagnosis is mandatory to prevent potentially life-threatening bleeding complications. We present the case of an 85-year-old woman admitted to hospital with symptoms of respiratory infection who 12 hours later developed haematuria which required transfusion. Laboratory assays showed an isolated prolonged aPTT, a moderately reduced FVIII and a high inhibitor titre. Influenza A and Escherichia coli were also identified. Antivirals, antibiotics, immunosuppressive drugs and haemostatic agents were started. Two weeks later, the inhibitor was not detected, and bleeding and symptoms of infection had resolved. Immunosuppressive drugs were stopped on day 45 and there has been no recurrence since then. To date, no FVIII inhibitors have been reported in concomitant infection with influenza A and urinary E. coli. The identification of conditions potentially associated with AHA is essential to achieve complete remission., Learning Points: The lack of awareness of and experience with acquired haemophilia (AHA) suggests that diagnosis is frequently delayed, resulting in suboptimal treatment.AHA should be suspected in recent-onset abnormal bleeding in patients not receiving anticoagulant treatment, and in the presence of isolated prolonged activated partial thromboplastin time (aPTT).Treatment is based on eradication of the inhibitor, control of the bleeding and identification of underlying conditions., Competing Interests: Conflicts of Interests: The Authors declare that there are no competing interests., (© EFIM 2020.)

Background: Splenic artery aneurysms are rare, potentially serious, and usually asymptomatic. Several methods are currently available to treat them, each with their own advantages and drawbacks. Therefore, its therapeutic paradigm has changed., Methods: We review our database of splenic aneurysms (2009-2019) and undertake an exhaustive literature review. Demographic, clinical, diagnostic, therapeutic, early and follow-up outcome data were examined. Our experience comprised: 15 patients with 19 splenic aneurysms. 11 women (average age, 59.4 years) and 4 men (average age, 61.7 years). All asymptomatic., Results: At diagnosis, aneurysms had a mean cross-sectional diameter of 3.4 cm (3.2 and 3.9 for women and men, respectively), the largest measuring 8.5 cm. Two independent aneurysms were detected in four patients. Diagnoses were always incidental to a CT scan. Treatments consisted of open surgery (2 patients), endovascular surgery (10 patients: 7 embolizations, 3 covered stent) and observation/follow-up (3 patients). The cases of open surgery (with splenectomy) were carried out without postoperative morbidity. One embolization failed (requiring subsequent open surgery) and two suffered localized splenic infarction, but without further complications. In patients treated with a covered stent, the aneurysm was always excluded, without complications. There was no 30-day or follow-up (average 26.2 months) mortality. Splenic aneurysms are diagnosed more frequently and earlier (in the asymptomatic phase), albeit incidentally, than in the past., Conclusions: The correct indication (identifying patients at risk) and individualization of treatment, in which endovascular techniques are the first-line option, have significantly improved morbidity and mortality outcomes in our hospital.

We report on the case of spontaneous rupture of an On-X-pure pyrolytic carbon mechanical valve prosthesis implanted seven years earlier, in a mitral position, at our hospital. The patient was admitted with valvular dysfunction and acute pulmonary edema requiring emergency surgery (prosthesis replacement); the absence of a leaflet was confirmed intraoperatively. The patient presented severe respiratory failure, which prolonged the postoperative period. A CT scan showed that the migrated leaflet was located in the aortic bifurcation with no apparent arterial lesion. Four months later, once the patient had recovered, laparotomy and aortotomy were performed in order to retrieve the leaflet, which was found to have become included (neoendothelized) in the aortic wall without compromising the latter's integrity or obstructing the blood flow. A subsequent CT scan confirmed the persistence of the leaflet in its initial position. The literature review highlights two singular facts: 1) this is the second published case of the escape of a leaflet from an On-X prosthesis (the first patient died); 2) this is the first case in which a laparotomy was performed to retrieve the leaflet but finally a decision was made to leave it in situ. Seven months later, the patient remained asymptomatic.

C3G is a GEF (guanine nucleotide exchange factor) for Rap GTPases, among which the isoform Rap1b is an essential protein in platelet biology. Using transgenic mouse models with platelet-specific overexpression of C3G or mutant C3GΔCat, we have unveiled a new function of C3G in regulating the hemostatic function of platelets through its participation in the thrombin-PKC-Rap1b pathway. C3G also plays important roles in angiogenesis, tumor growth, and metastasis through its regulation of the platelet secretome. In addition, C3G contributes to megakaryopoiesis and thrombopoiesis. Here, we used a platelet-specific C3G-KO mouse model to further support the role of C3G in hemostasis. C3G-KO platelets showed a significant delay in platelet activation and aggregation as a consequence of the defective activation of Rap1, which resulted in decreased thrombus formation in vivo. Additionally, we explored the contribution of C3G-Rap1b to platelet signaling pathways triggered by thrombin, PMA or ADP, in the referenced transgenic mouse model, through the use of a battery of specific inhibitors. We found that platelet C3G is phosphorylated at Tyr504 by a mechanism involving PKC-Src. This phosphorylation was shown to be positively regulated by ERKs through their inhibition of the tyrosine phosphatase Shp2. Moreover, C3G participates in the ADP-P2Y12-PI3K-Rap1b pathway and is a mediator of thrombin-TXA 2 activities. However, it inhibits the synthesis of TXA 2 through cPLA 2 regulation. Taken together, our data reveal the critical role of C3G in the main pathways leading to platelet activation and aggregation through the regulation of Rap1b.

Very few data exist on when a particular thrombopoietin-receptor agonist (TPO-RA) is favored in clinical practice for the treatment of patients with immune thrombocytopenia (ITP), about novel risk factors for vascular events (VE) with these drugs, nor about predictive factors for therapy free responses (TFR). We conducted an observational, retrospective, long-term follow-up multicenter study from November 2016 to January 2018 of 121 adult ITP patients initiating TPO-RA between January 2012 to December 2014. Data reflected that a platelet count ≤25 × 10 9 /l at the time when the TPO-RA was initiated was associated with a 2.8 higher probability of receiving romiplostim vs. eltrombopag (P = 0.010). VE on TPO-RA was related to previous neoplasia in patients over 65 years (50% vs. 2.2%, P < 0.001), and to previous splenectomy in younger patients (100% vs. 33%, P = 0.001). Receiving romiplostim as first TPO-RA with no subsequent TPO-RA switching was associated with a 50% likelihood of TFR after 2.9 years of therapy (3.3 years in chronic ITP patients). These real-world data help deciphering some areas of uncertainty, and offer insight into some of the most relevant challenges of ITP which may help clinicians make appropriate treatment decisions in the management of adult ITP patients with TPO-RA.

Diagnosis of inherited bleeding disorders (IBDs) remains challenging, especially in the case of inherited platelet disorders, due to the heterogeneity of the clinical and laboratory phenotype, the limited specificity of platelet function tests, and the large number of potential culprit genes. Unraveling the underlying molecular defect provides the definitive diagnosis of IBDs, facilitating prognosis and clinical care, which are especially important for severe clinical syndromes and those that may be associated with an increased risk of malignancy. Until recently, Sanger sequencing of candidate genes has been the only method of molecular diagnosis, but this approach is time-consuming and costly and requires phenotype-based identification of any obvious candidate gene(s). Nowadays, high-throughput sequencing (HTS) allows the simultaneous and rapid investigation of multiple genes at a manageable cost. This HTS technology that includes targeted sequencing of prespecified genes, whole-exome sequencing, or whole-genome sequencing, is revolutionizing the genetic diagnosis of human diseases. Through its extensive implementation in research and clinical practice, HTS is rapidly improving the molecular characterization of IBDs. However, despite the availability of this powerful approach, many patients still do not receive a diagnosis. As IBDs are complex and rare diseases, development of more advanced laboratory assays, improvements in bioinformatic pipelines, and the formation of multidisciplinary teams are encouraged to advance our understanding of IBDs., Competing Interests: None., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Persistent thrombocytopenia is a common complication after allogeneic hematopoietic stem cell transplantation (allo-SCT). Romiplostim and eltrombopag are the currently available thrombopoietin receptor agonists (TPO-RAs), and some studies with very small numbers of cases have reported their potential efficacy in the allo-SCT setting. The present retrospective study evaluated the safety and efficacy of TPO-RAs in 86 patients with persistent thrombocytopenia after allo-HSCT. Sixteen patients (19%) had isolated thrombocytopenia (PT), and 71 (82%) had secondary failure of platelet recovery (SFPR). TPO-RA therapy was started at a median of 127 days (range, 27 to 1177 days) after allo-SCT. The median initial and maximum administered doses were 50 mg/day (range, 25 to 150 mg/day) and 75 mg/day (range, 25 to 150 mg/day), respectively, for eltrombopag and 1 µg/kg (range, 1 to 7 µg/kg) and 5 µg/kg (range, 1 to 10 µg/kg), respectively, for romiplostin. The median platelet count before initiation of TPO-RA therapy was 14,000/µL (range, 1000 to 57,000/µL). Platelet recovery to ≥50,000/µL without transfusion support was achieved in 72% of patients at a median time of 66 days (range, 2 to 247 days). Eighty-one percent of the patients had a decreased number of megakaryocytes before treatment, showing a slower response to therapy (P = .011). The median duration of treatment was 62 days (range, 7 to 700 days). Grade 3-4 adverse events (hepatic and asthenia) were observed in only 2% of the patients. At last follow-up, 81% of patients had discontinued TPO-RAs and maintained response, and 71% were alive. To our knowledge, this is the largest series analyzing the use of TPO-RAs after allo-SCT reported to date. Our results support the efficacy and safety in this new setting. Further prospective trials are needed to increase the level of evidence and to identify predictors of response., (Copyright © 2019 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc. All rights reserved.)

Presently, no data on the molecular basis of hereditary protein C (PC) deficiency in Spain is available. We analyzed the PC gene ( PROC ) in 109 patients with symptomatic PC deficiency and in 342 relatives by sequencing the 9 PROC exons and their flanking intron regions. In 93 probands, we found 58 different mutations (26 novel). Thirty-seven consisted of a nucleotide change, mainly missense mutations, 1 was a 6-nucleotide insertion causing the duplication of 2 amino acids, and 4 were deletions of 1, 3, 4, and 16 nucleotides. Nine mutations caused type II deficiencies, with the presence of normal antigen levels but reduced anticoagulant activity. Using a PC level of 70% as lowest normal limit, we found no mutations in 16 probands and 25 relatives with PC levels ≤ 70%. On the contrary, 4 probands and 12 relatives with PC levels > 70% carried the mutation identified in the proband. The spectrum of recurrent mutations in Spain is different from that found in the Netherlands, where the most frequent mutations were p.Gln174* and p.Arg272Cys, and is more similar to that found in France, where the most frequent were p.Arg220Gln and p.Pro210Leu. In our study, p.Val339Met (9 families), p.Tyr166Cys (7), p.Arg220Gln (6), and p.Glu58Lys (5) were the most prevalent. This study confirms the considerable heterogeneity of the genetic abnormality in PC deficiencies, and allowed genetic counseling to those individuals whose PC levels were close to the lower limit of the normal reference range., Competing Interests: F.E. reports grants from Spanish Society of Thrombosis and Haemostasis, during the conduct of the study; P.M. reports grants from Spanish Society of Thrombosis and Haemostasis, during the conduct of the study; S.N. reports grants from Spanish Society of Thrombosis and Haemostasis, during the conduct of the study. Other authors report no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

Primary immune thrombocytopenia (ITP) is a bleeding disorder that conventionally has been treated with steroids or other immunosuppressive treatments. The introduction of thrombopoietin receptor agonists (TPO-RAs), which increase platelet production, dramatically changed the treatment landscape for ITP by providing patients with well-tolerated, long-term treatment options. Two TPO-RAs, eltrombopag and romiplostim, have been approved in the United States and European Union for the treatment of ITP. Some patients do not benefit from the first TPO-RA they receive, so it is assumed that the alternate TPO-RA would have the same outcome. However, eltrombopag and romiplostim have distinct pharmacodynamic and pharmacokinetic properties and may have different tolerability and efficacy in individual patients with ITP. Published retrospective studies showed that >75% of patients who switched to the alternate TPO-RA maintained or achieved a response with the new treatment. Notably, most patients who switched due to lack of efficacy with the first TPO-RA responded to the alternate TPO-RA, which demonstrates an absence of cross-resistance between the two drugs. Therefore, switching to the alternate TPO-RA if the first TPO-RA fails to demonstrate a response should be considered before the use of a less-preferable option., Competing Interests: Conflict of interest statement: Dr. González-Porras and Dr. Carpenedo have nothing to disclose. Dr. Godeau reports grants and personal fees from Amgen, personal fees from Novartis, personal fees from LFB, grants and personal fees from Roche, and personal fees from Argenx, outside the submitted work.

: We hypothesized that inhibitor specificity may predict the outcome of antifactor VIII autoantibodies eradication treatment in acquired hemophilia A. Our objective was to analyze the association between factor VIII domains recognized by inhibitors and outcome of the immunosuppressive therapies (ISTs) in a prospective, observational study. 16 patients were recruited. Inhibitor specificities were assessed at diagnosis and throughout the study. Their association with IST outcome was addressed. First-line IST succeeded in 56% of patients. Inhibitors reacted mainly with light chain domains (69%) and/or the A2 domain (44%). 31% inhibitors recognized more than one domain. Significantly, the number of patients whose inhibitors recognized the light chain was significantly higher in the group of those who did not reach complete remission after first line IST when compared with those who did [6/7 (85.7%) vs. 4/9 (44.4%), P < 0.05]. Therefore, inhibitor specificity could predict the success of IST in acquired hemophilia A.

Background: Hermansky-Pudlak syndrome (HPS) is a rare inherited platelet disorder characterized by bleeding diathesis, oculocutaneous albinism (OCA) and a myriad of often-serious clinical complications. Methods: We established the clinical and laboratory phenotype and genotype of six unrelated pedigrees comprising ten patients with clinical suspicion of HPS; including platelet aggregation, flow cytometry, platelet dense granule content, electron microscopy and high-throughput sequencing (HTS). Results: The clinical presentation showed significant heterogeneity and no clear phenotype-genotype correlations. HTS revealed two known and three novel disease-causing variants. The Spanish patients carried a homozygous p.Pro685Leufs17* deletion ( n  = 2) in HPS4 , or the novel p.Arg822* homozygous variant ( n  = 1) in HPS3 . In the case of two Turkish sisters, a novel missense homozygous HPS4 variant (p.Leu91Pro) was found. In two Portuguese families, genetic studies confirmed a previously reported nonsense variant (p.Gln103*) in DTNBP1 in three patients and a novel duplication (p.Leu22Argfs*33) in HPS6 in two unrelated patients. Conclusions: Our findings expand the mutational spectrum of HPS, which may help in investigating phenotype-genotype relationships and assist genetic counselling for affected individuals. This approach is a proof of principle that HTS can be considered and used in the first-line diagnosis of patients with biological and clinical manifestations suggestive of HPS. Key messages We established the relationships between the clinical and laboratory phenotype and genotype of six unrelated pedigrees comprising ten patients with clinical suspicion of HPS. Molecular analysis is useful in confirming the diagnosis and may offer some prognostic information that will aid in optimizing monitoring and surveillance for early detection of end-organ damage. This approach is a proof of principle that HTS can be considered and used in the first-line diagnosis of patients with biological and clinical manifestations suggestive of HPS.

Sitosterolemia is a recessive inherited metabolic disorder of unknown prevalence, characterized by increased levels of plasma plant sterols. It is caused by 28 and 31 variants in ABCG5 and ABCG8 genes, respectively, and is characterized by a predisposition to hyperabsorption and accumulation of toxic levels of plant sterols in plasma. Its clinical picture is extremely heterogeneous. The main clinical features are tendinous and cutaneous xanthomas, arthritis or arthralgia, premature cardiovascular disease and atherosclerosis. These characteristics are shared with familial hypercholesterolemia (FH), making it possible for sitosterolemia to be misdiagnosed as homozygous FH, especially in pediatric patients. In such cases, a specific chromatography-based laboratory method is essential to differentiate sitosterol and cholesterol. Hematological abnormalities (hemolytic anemia and macrothrombocytopenia) may be present in 25-35% of patients, in whom it is usually associated with the main clinical features, as occurs in the 70% of the cases. In this context, the peripheral blood smear is essential and reveals giant platelets and stomatocytes. Only 21 causative variants in ABCG5/ABCG8 are associated with macrothrombocytopenia. Most physicians still do not recognize these hematological abnormalities or relate them to sitosterolemia. Patients may suffer long-term misdiagnosis of immune thrombocytopenia and be at high risk of receiving harmful therapies or of not benefitting from a low-cholesterol diet and/or from the gold standard treatment with ezetimibe. This drug reduces the levels of plasma plant sterols, provokes regression of xanthomas, and can alleviate hematological abnormalities. Finally, to identify genetic defects, recent advances in high-throughput sequencing, especially in the use of targeted sequencing of pre-specified genes, have begun to be incorporated in the first-line approach in the field of genetic disorders., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Despite the growing interest and improved knowledge about venous thromboembolism in cancer patients in the last years, there are still many unsolved issues. Due to the limitations of the available literature, evidence-based clinical practice guidelines are not able to give solid recommendations for challenging scenarios often present in the setting of cancer-associated thrombosis (CAT). A multidisciplinary expert panel from three scientific societies-Spanish Society of Internal Medicine (SEMI), Spanish Society of Medical Oncology (SEOM), and Spanish Society Thrombosis and Haemostasis (SETH)-agreed on 12 controversial questions regarding prevention and management of CAT, which were thoroughly reviewed to provide further guidance. The suggestions presented herein may facilitate clinical decisions in specific complex circumstances, until these can be made leaning on reliable scientific evidence.

The RASGRP2 gene encodes the Ca 2+ and DAG-regulated guanine nucleotide exchange factor I (CalDAG-GEFI), which plays a key role in integrin activation in platelets and neutrophils. We here report two new RASGRP2 variants associated with platelet dysfunction and bleeding in patients. The homozygous patients had normal platelet and neutrophil counts and morphology. Platelet phenotyping showed: prolonged PFA-100 closure times; normal expression of major glycoprotein receptors; severely reduced platelet aggregation response to ADP and collagen (both patients); aggregation response to PAR1 and arachidonic acid markedly impaired in one patient; PMA-induced aggregation unaffected; platelet secretion, clot retraction, and spreading minimally affected. Genetic analysis identified two new homozygous variants in RASGRP2: c.706C>T (p.Q236X) and c.887G>A (p.C296Y). In both patients, CalDAG-GEFI protein was not detectable in platelet lysates, and platelet αIIbβ3 activation, as assessed by fibrinogen binding, was greatly impaired in response to all agonists except PMA. Patient neutrophils showed normal integrin expression, but impaired Mn 2+ -induced fibrinogen binding. In summary, we have identified two new RASGRP2 mutations that can be added to this rapidly growing form of inherited platelet function disorder.

Inherited platelet disorders are a heterogeneous group of rare diseases, caused by inherited defects in platelet production and/or function. Their genetic diagnosis would benefit clinical care, prognosis and preventative treatments. Until recently, this diagnosis has usually been performed via Sanger sequencing of a limited number of candidate genes. High-throughput sequencing is revolutionizing the genetic diagnosis of diseases, including bleeding disorders. We have designed a novel high-throughput sequencing platform to investigate the unknown molecular pathology in a cohort of 82 patients with inherited platelet disorders. Thirty-four (41.5%) patients presented with a phenotype strongly indicative of a particular type of platelet disorder. The other patients had clinical bleeding indicative of platelet dysfunction, but with no identifiable features. The high-throughput sequencing test enabled a molecular diagnosis in 70% of these patients. This sensitivity increased to 90% among patients suspected of having a defined platelet disorder. We found 57 different candidate variants in 28 genes, of which 70% had not previously been described. Following consensus guidelines, we qualified 68.4% and 26.3% of the candidate variants as being pathogenic and likely pathogenic, respectively. In addition to establishing definitive diagnoses of well-known inherited platelet disorders, high-throughput sequencing also identified rarer disorders such as sitosterolemia, filamin and actinin deficiencies, and G protein-coupled receptor defects. This included disease-causing variants in DIAPH1 (n=2) and RASGRP2 (n=3). Our study reinforces the feasibility of introducing high-throughput sequencing technology into the mainstream laboratory for the genetic diagnostic practice in inherited platelet disorders., (Copyright© 2018 Ferrata Storti Foundation.)

Previous observations indicated that C3G (RAPGEF1) promotes α-granule release, evidenced by the increase in P-selectin exposure on the platelet surface following its activation. The goal of the present study is to further characterize the potential function of C3G as a modulator of the platelet releasate and its implication in the regulation of angiogenesis. Proteomic analysis revealed a decreased secretion of anti-angiogenic factors from activated transgenic C3G and C3G∆Cat platelets. Accordingly, the secretome from both transgenic platelets had an overall pro-angiogenic effect as evidenced by an in vitro capillary-tube formation assay with HUVECs (human umbilical vein endothelial cells) and by two in vivo models of heterotopic tumor growth. In addition, transgenic C3G expression in platelets greatly increased mouse melanoma cells metastasis. Moreover, immunofluorescence microscopy showed that the pro-angiogenic factors VEGF and bFGF were partially retained into α-granules in thrombin- and ADP-activated mouse platelets from both, C3G and C3GΔCat transgenic mice. The observed interaction between C3G and Vesicle-associated membrane protein (Vamp)-7 could explain these results. Concomitantly, increased platelet spreading in both transgenic platelets upon thrombin activation supports this novel function of C3G in α-granule exocytosis. Collectively, our data point out to the co-existence of Rap1GEF-dependent and independent mechanisms mediating C3G effects on platelet secretion, which regulates pathological angiogenesis in tumors and other contexts. The results herein support an important role for platelet C3G in angiogenesis and metastasis., Competing Interests: CONFLICTS OF INTEREST The authors declare no competing financial interests.

Background: Acquired hemophilia A (AHA) is a rare bleeding disease caused by autoantibodies against factor VIII. Spontaneous bleeding symptoms usually affect the skin and muscle, while pericardial effusion is an extremely rare manifestation. In the elderly, anticoagulant treatment is frequent and bleeding symptoms are usually associated with this., Clinical Findings: We report a hemorrhagic pericardial effusion as the AHA debut in a patient with untreated chronic lymphocytic leukemia and anticoagulated with apixaban for atrial fibrillation and chronic arterial ischemia. The patient was treated with recombinant activated factor VII to control the active bleeding and corticosteroids and cyclophosphamide to eradicate the inhibitor. In addition, a briefly review of hematological malignancies associated to acquired hemophilia was performed. PARTICULARITIES:: a) anticoagulant treatment may confuse the suspicion of AHA and its diagnosis; b) hemorrhagic pericardial effusion is an extremely rare presentation; c) bypassing agents raise the risk of thromboembolism; d) hematological malignancies rarely cause AHA (<20% of cases)., Conclusion: A multidisciplinary team is needed to diagnose and manage AHA effectively. The use of anticoagulants may lead to the misdiagnosis of clinical symptoms. Chronic lymphocytic leukemia is one of the main causes of hematological malignancies associated. The specific treatment of CLL is still recommended in the event of active disease., (Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Eltrombopag is safe and effective in primary chronic ITP. However, lack of clinical trials avoids a clear demonstration of its utility in newly diagnosed and persistent ITP. Our aim here is to report Spanish results for this type of patients. We retrospectively evaluated 220 adult primary ITP patients. According to standard definition, patients were allocated to newly diagnosed (n = 30), persistent (n = 30), and chronic (n = 160) ITP. Groups were homogenous regarding most relevant parameters. 180 (90%) of 220 patients achieved a platelet response (R) with 167 (75.9%) complete responses (CR) after a 15-month follow-up. No statistical significant differences among groups but a trend towards a greater efficacy in newly diagnosed ITP were observed (93.3% of responses with 86.7% of CR). Efficacy in persistent ITP (83.3% of responses with 80.0% of CR) and chronic ITP (79.4% of responses with 73.1% of CR) was similar. 70 patients (31.8%) experienced adverse events. 15 of them were grade 3-4. Most common adverse effects were headache and hepatobiliary laboratory abnormalities (HBLAs). One persistent ITP had a venous thrombosis and one chronic ITP had grade II myelofibrosis. We consider Eltrombopag use for the early stage ITP as effective and safe as it is in chronic ITP.

Essentials Diagnosis of sitosterolemia, a rare recessive or syndromic disorder, is usually delayed. Peripheral blood smear is extremely useful for establishing the suspicion of sitosterolemia. High-throughput sequencing technology enables the molecular diagnosis of inherited thrombocytopenias. Accurate characterization of sitosterolemia helps us determine appropriate management., Summary: Background Sitosterolemia (STSL) is a recessive inherited disorder caused by pathogenic variants in the ABCG5 and ABCG8 genes. Increased levels of plasma plant sterols (PSs) usually result in xanthomas and premature coronary atherosclerosis, although hematologic abnormalities may occasionally be present. This clinical picture is unfamiliar to many physicians, and patients may be at high risk of misdiagnosis. Objectives To report two novel ABCG5 variants causing STSL in a Spanish patient, and review the clinical and mutational landscape of STSL. Patient/Methods A 46-year-old female was referred to us with lifelong macrothrombocytopenia. She showed familial hypercholesterolemia-related xanthomas. Molecular analysis was performed with high-throughput sequencing. Plasma PS levels were evaluated with gas-liquid chromatography. The STSL landscape was reviewed with respect to specific online databases and all reports published since 1974. Results A blood smear revealed giant platelets and stomatocytes. Novel compound heterozygous variants were detected in exons 7 (c.914C>G) and 13 (c.1890delT) of ABCG5. The patient showed an increased plasma level of sitosterol. These findings support the diagnosis of STSL. In our review, we identified only 25 unrelated STLS patients who presented with hematologic abnormalities including macrothrombocytopenia. It remains unknown why only some patients develop hematologic abnormalities. Conclusions This is the first Spanish STSL patient to be reported and molecularly characterized. The early diagnosis of STLS is strongly supported by the presence of stomatocytes in blood smears. The definitive diagnosis of STSL by measurement of serum PS levels and molecular analyses prompted the use of ezetimibe therapy., (© 2017 International Society on Thrombosis and Haemostasis.)