Platelet C3G: a key player in vesicle exocytosis, spreading and clot retraction

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.

Key Genes of the Immune System and Predisposition to Acquired Hemophilia A: Evidence from a Spanish Cohort of 49 Patients Using Next-Generation Sequencing

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 × 103, 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 (nallele = 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.

Inherited Thrombocytopenia Caused by Variants in Crucial Genes for Glycosylation

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.

Novel variants in GALE cause syndromic macrothrombocytopenia by disrupting glycosylation and thrombopoiesis

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.

The Limitations and Unmet Needs of the Five Cornerstones to Guarantee Lifelong Optimization of Prophylaxis in Hemophilia Patients

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.

Functional Alterations Involved in Increased Bleeding in Hereditary Hemorrhagic Telangiectasia Mouse Models

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.

C-Reactive protein and SOFA scale: A simple score as early predictor of critical care requirement in patients with COVID-19 pneumonia in Spain

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.

Characterization of the Platelet Phenotype Caused by a Germline RUNX1 Variant in a CRISPR/Cas9-Generated Murine Model

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 (RUNX1WT/WT, RUNX1WT/L43S, and RUNX1L43S/L43S). Platelet phenotype was assessed by flow cytometry and confocal microscopy. On average, RUNX1L43S/L43S and RUNX1WT/L43S mice had a significantly longer tail-bleeding time than RUNX1WT/WT mice, indicating the variant's involvement in hemostasis. However, only homozygous mice displayed mild thrombocytopenia. RUNX1L43S/L43S and RUNX1WT/L43S displayed impaired agonist-induced spreading and α-granule release, with no differences in δ-granule secretion. Levels of integrin αIIbβ3 activation, fibrinogen binding, and aggregation were significantly lower in platelets from RUNX1L43S/L43S and RUNX1WT/L43S using phorbol 12-myristate 13-acetate (PMA), adenosine diphosphate (ADP), and high thrombin doses. Lower levels of PKC phosphorylation in RUNX1L43S/L43S and RUNX1WT/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 αIIbβ3 activation, aggregation, α-granule secretion, and platelet spreading, mimicking the phenotype associated with RUNX1 variants in the clinical setting.

Abdominal aortic aneurysm and acute appendicitis: a case report and review of the literature

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.

C-Reactive protein and SOFA scale: A simple score as early predictor of critical care requirement in patients with COVID-19 pneumonia in Spain

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=.0043) and higher Sequential Organ Failure Assessment (SOFA) score (1.968 [1.389-2.590]; P<.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<.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 ≥9,1mg/mL could be at high risk to require critical care.

Cost-per-responder analysis for eltrombopag and rituximab in the treatment of primary immune thrombocytopenia in Spain

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.

Acquired Haemophilia A in Association with Influenza A and Urinary Tract Infection

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.

C3G contributes to platelet activation and aggregation by regulating major signaling pathways

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-TXA2 activities. However, it inhibits the synthesis of TXA2 through cPLA2 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.

Transcriptomic analysis of patients with immune thrombocytopenia treated with eltrombopag

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 × 10⁹/L (range, 2-68 × 10⁹/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.

Thrombopoietin Receptor Agonists for Severe Thrombocytopenia after Allogeneic Stem Cell Transplantation: Experience of the Spanish Group of Hematopoietic Stem Cell Transplant

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.

Molecular Diagnosis of Inherited Coagulation and Bleeding Disorders

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.

Cancer-Associated Thrombosis: Beyond Clinical Practice Guidelines-A Multidisciplinary (SEMI-SEOM-SETH) Expert Consensus

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.

C3G promotes a selective release of angiogenic factors from activated mouse platelets to regulate angiogenesis and tumor metastasis

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.

Two novel variants of the ABCG5 gene cause xanthelasmas and macrothrombocytopenia: a brief review of hematologic abnormalities of sitosterolemia

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.

Identification of two novel mutations in RASGRP2 affecting platelet CalDAG-GEFI expression and function in patients with bleeding diathesis

The RASGRP2 gene encodes the Ca²⁺ 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 Mn²⁺-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.

[Clinical perspectives on the management of bleeding in patients on oral anticoagulants: the DECOVER Study (DElphi Consensus on oral COagulation and therapy action reVERsal)]

OBJECTIVES

To evaluate the level of agreement between hematologists and emergency medicine physicians regarding the best clinical practices for managing bleeding and anticoagulant reversal.

MATERIAL AND METHODS

Nationwide Spanish multicenter Delphi method study with a panel of experts on anticoagulation and the management of bleeding. Two survey rounds were carried out between April and September 2015. Consensus was reached when more than 75% of the panelists scored items in the same tertile.

RESULTS

Fifteen hematologists and 17 emergency medicine specialists from 14 Spanish autonomous communities participated. Consensus was reached on the use of both hemodialysis and an activated prothrombin complex concentrate (PCC) to antagonize significant/major bleeding in patients taking dabigatran. Use of an activated PCC was considered sufficient for patients on rivaroxaban or apixaban. The panel did not consider any PCC to be both effective and safe. Tests for activated partial thromboplastin, thrombin, diluted thrombin, and ecarin clotting times were considered useful in patients treated with dabigatran. A specific anti-Xa activity assay was suggested for patients who developed bleeds while treated with rivaroxaban or apixaban. Specific antidotes for direct-acting oral anticoagulants would be useful when severe bleeding occurs according to 97% of the panelists. Such antidotes would substantially change current treatment algorithms.

CONCLUSION

The points of consensus were generally in line with clinical practice guidelines, but the Delphi process revealed that there are aspects of the clinical management of bleeding that require unified criteria. The need for specific antidotes for direct-acting oral anticoagulants was emphasized.

Novel approaches for diagnosing inherited platelet disorders

Inherited platelet disorders diagnosis is based on the clinical history and bleeding assessment tools. The laboratory functional assays as well as the molecular test to identify the pathogenic genetic variant are essential to confirm the accurate diagnosis of these disorders. Nowadays, the main challenges to developing a new diagnostic system are involved in reducing the samples' volume, and faster and more helpful analysis. Moreover, there are no widely available and standardised global tests. High throughput genetic testing such as next-generation sequencing has revolutionised DNA sequencing technologies as it allows the simultaneous and faster investigation of multiple genes at a manageable cost. This technology has improved the molecular characterisation of inherited platelet disorders and has been implemented in the research studies and the clinical routine practice.

Hsp70 protects from stroke in atrial fibrillation patients by preventing thrombosis without increased bleeding risk

AIMS

Atrial fibrillation (AF) is a major risk factor for cardio-embolic stroke. Anticoagulant drugs are effective in preventing AF-related stroke. However, the high frequency of anticoagulant-associated major bleeding is a major concern. This study sought to identify new targets to develop safer antithrombotic therapies.

METHODS AND RESULTS

Here, microarray analysis in peripheral blood cells in eight patients with AF and stroke and eight AF subjects without stroke brought to light a stroke-related gene expression pattern. HSPA1B, which encodes for heat-shock protein 70 kDa (Hsp70), was the most differentially expressed gene. This gene was down-regulated in stroke subjects, a finding confirmed further in an independent AF cohort of 200 individuals. Hsp70 knock-out mice subjected to different thrombotic challenges developed thrombosis significantly earlier than their wild-type (WT) counterparts. Remarkably, the tail bleeding time was unchanged. Accordingly, both TRC051384 and tubastatin A, i.e. two Hsp70 inducers via different pathways, delayed thrombus formation in WT mice, the tail bleeding time still being unaltered. Most interestingly, Hsp70 inducers did not increase the bleeding risk even when aspirin was concomitantly administered. Hsp70 induction was associated with an increased vascular thrombomodulin expression and higher circulating levels of activated protein C upon thrombotic stimulus.

CONCLUSIONS

Hsp70 induction is a novel approach to delay thrombus formation with minimal bleeding risk, and is especially promising for treating AF patients and in other situations where there is also a major bleeding hazard.

Eltrombopag safety and efficacy for primary chronic immune thrombocytopenia in clinical practice

BACKGROUND

Eltrombopag is effective and safe in chronic immune thrombocytopenia (ITP). However, clinical trials may not accurately reflect what happens in clinical practice. We evaluated the efficacy and safety of eltrombopag in primary chronic ITP in a real-world setting.

METHODS

A total of 164 primary patients with chronic ITP from 40 Spanish centers, who had been treated with eltrombopag, were retrospectively evaluated.

RESULTS

The median age of our cohort (72% women) was 63 yr (interquartile range, IQR, 45-75 yr). The median time with ITP diagnosis was 81 months (IQR, 30-192 months). The median number of therapies prior to eltrombopag was 3 (IQR, 2-4). At the time of eltrombopag start, 45 patients (30%) were receiving concomitant treatment for ITP. Forty-six patients (30%) had bleeding signs/symptoms the month before the treatment started. The median platelet count at eltrombopag initiation was 22 × 10(9) /L (IQR, 8-39 × 10(9) /L). A total of 135 patients (88.8%) achieved a platelet response. The median time to platelet response was 12 d (95% CI, 9-13 d). Maintained platelet response rate during the 15-month period under examination was 75.2%. Twenty-eight patients (18.4%) experienced adverse events, mainly grades 1-2.

CONCLUSION

Eltrombopag is highly effective and well tolerated in unselected patients with primary chronic ITP.

Short Leukocyte Telomere Length Is Associated With Cardioembolic Stroke Risk in Patients With Atrial Fibrillation

BACKGROUND AND PURPOSE

The risk of cardioembolic stroke in patients with atrial fibrillation (AF) cannot be accurately assessed and novel tools are needed to improve prediction. We hypothesize that telomere shortening constitutes a novel risk factor for cardioembolic stroke in patients with AF.

METHODS

The peripheral blood leukocyte telomere length (LTL) was determined by real-time polymerase chain reaction in 187 patients with AF, 93 of them without stroke history and 94 of them having suffered 1 cardioembolic stroke. Percentiles were calculated according to LTL values in the nonstroke group to estimate the cardioembolic stroke risk associated with LTL using logistic regression models.

RESULTS

Short LTL values were independently and dose-dependently associated with an increased risk of cardioembolic stroke, with an odds ratio (95% confidence interval) of 2.93 (1.24-6.94) and 6.26 (2.01-19.52), respectively, for sex, hypertension, diabetes mellitus, heart failure, and age-adjusted models using the LTL 10th and 5th percentile cut-offs, respectively.

CONCLUSIONS

Telomere shortening is associated with cardioembolic stroke risk in patients with AF. Prospective studies are encouraged to establish the value of LTL to improve prediction tools to categorize cardioembolic stroke risk in AF.

Self-administered versus interview-based questionnaires among patients with intermittent claudication: Do they give different results? A cross-sectional study

CONTEXT AND OBJECTIVE

Many clinical investigations use generic and/or specific questionnaires to obtain information about participants and patients. There is disagreement about whether the administration method can affect the results. The aim here was to determine whether, among patients with intermittent claudication (IC), there are differences in the Walking Impairment Questionnaire (WIQ) and European Quality of Life-5 Dimension (EQ-5D) scores with regard to: 1) the questionnaire administration method (self-administration versus face-to-face interview); and 2) the type of interviewer (vascular surgeon, VS, versus general practitioner, GP).

DESIGN AND SETTING

Cross-sectional observational multicenter epidemiological study carried out within the Spanish National Health Service.

METHODS

1,641 evaluable patients with IC firstly completed the WIQ and EQ-5D questionnaires and then were interviewed by their doctor on the same day. Pearson correlations and Chi-square tests were used.

RESULTS

There was a strong correlation (r > 0.800; P < 0.001) between the two methods of administering the WIQ and EQ-5D questionnaires, and between the VS and GP groups. Likewise, there was a high level of concordance (P > 0.05) between the different dimensions of the WIQ-distance and EQ-5D (self-administration versus face-to-face) in the VS and GP groups.

CONCLUSION

There was no difference between the different methods of administering the WIQ and EQ-5D questionnaires, among the patients with IC. Similarly, the two types of interviewers (VS or GP) were equally valid. Therefore, it seems unnecessary to expend effort to administer these questionnaires by interview, in studies on IC.

Successful discontinuation of eltrombopag after complete remission in patients with primary immune thrombocytopenia

Eltrombopag is effective and safe in immune thrombocytopenia (ITP). Some patients may sustain their platelet response when treatment is withdrawn but the frequency of this phenomenon is unknown. We retrospectively evaluated 260 adult primary ITP patients (165 women and 95 men; median age, 62 years) treated with eltrombopag after a median time from diagnosis of 24 months. Among the 201 patients who achieved a complete remission (platelet count >100 × 10(9) /l), eltrombopag was discontinued in 80 patients. Reasons for eltrombopag discontinuation were: persistent response despite a reduction in dose over time (n = 33), platelet count >400 × 10(9) /l (n = 29), patient's request (n = 5), elevated aspartate aminotransferase (n = 3), diarrhea (n = 3), thrombosis (n = 3), and other reasons (n = 4). Of the 49 evaluable patients, 26 patients showed sustained response after discontinuing eltrombopag without additional ITP therapy, with a median follow-up of 9 (range, 6-25) months. These patients were characterized by a median time since ITP diagnosis of 46.5 months, with 4/26 having ITP < 1 year. Eleven patients were male and their median age was 59 years. They received a median of 4 previous treatment lines and 42% were splenectomized. No predictive factors of sustained response after eltrombopag withdrawal were identified. Platelet response following eltrombopag cessation may be sustained in an important percentage of adult primary ITP patients who achieved CR with eltrombopag. However, reliable markers for predicting which patients will have this response are needed.

Use of eltrombopag after romiplostim in primary immune thrombocytopenia

The thrombopoietin receptor agonists (THPO-RAs), romiplostim and eltrombopag, are effective and safe in immune thrombocytopenia (ITP). However, the value of their sequential use when no response is achieved or when adverse events occur with one THPO-RA has not been clearly established. Here we retrospectively evaluated 51 primary ITP adult patients treated with romiplostim followed by eltrombopag. The median age of our cohort was 49 (range, 18-83) years. There were 32 women and 19 men. The median duration of romiplostim use before switching to eltrombopag was 12 (interquartile range 5-21) months. The reasons for switching were: lack of efficacy (n = 25), patient preference (n = 16), platelet-count fluctuation (n = 6) and side-effects (n = 4). The response rate to eltrombopag was 80% (41/51), including 67% (n = 35) complete responses. After a median follow-up of 14 months, 31 patients maintained their response. Efficacy was maintained after switching in all patients in the patient preference, platelet-count fluctuation and side-effect groups. 33% of patients experienced one or more adverse events during treatment with eltrombopag. We consider the use of eltrombopag after romiplostim for treating ITP to be effective and safe. Response to eltrombopag was related to the cause of romiplostim discontinuation.

Relative value of the Ankle-Brachial Index of intermittent claudication

INTRODUCTION

The Ankle-Brachial Index (ABI) makes it possible to identify patients with peripheral artery disease (PAD). Intermittent claudication (IC) is the first major symptom of PAD, although many patients with an ABI ≤ 0.9 do not exhibit IC, and the range of ABI among those who do have IC is very variable. This study evaluates the correlation between ABI and the perception (symptomatology) of claudicant patients.

MATERIAL AND METHODS

An observational, cross-sectional and multicentre, study of 920 patients with IC. Clinical history, ABI, Walking Impairment Questionnaire (WIQ) and European Quality of Life Questionnaire (EQ-5D) were recorded. Associations were analysed using Spearman's correlation coefficient.

RESULTS

The mean ABI of the series was 0.63 (SD = 0.19). The mean WIQ-distance was 34.07 (SD = 26.77), values being smaller for lower ABI values (r = 0.343, p < 0.001). The mean EQ-5D score of the series was 0.58 (SD = 0.21), also showing lower values as the ABI decreased (r = 0.278, p < 0.001). The correlations of WIQ and EQ-5D with ABI were statistically significant in both cases, but always less than 0.400 (between 0.278 and 0.343).

CONCLUSIONS

The correlations of ABI with the questionnaires of walking capacity and quality of life are weak. For this reason, although in clinical practice the ABI of CI patients is commonly measured, decisions should not be taken during the development of IC exclusively on the basis of the ABI.

Sustained response after discontinuation of short-and medium-term treatment with eltrombopag in patients with immune thrombocytopenia

Eltrombopag is effective and safe in chronic immune thrombocytopenia (ITP) patients not responding to previous therapy. However, when eltrombopag is discontinued, platelet counts usually return to baseline within 2 weeks. Here, we describe the clinical characteristics of the, to the best of our knowledge, largest case series of patients with ITP, who presented sustained responses after discontinuing eltrombopag (n = 12). The median time from diagnosis to eltrombopag initiation was 24 months (range, 1-480). The median number of prior therapies was 5 (range, 1-7), and the median duration of eltrombopag treatment was 5 months (range, 1-13). Three patients received eltrombopag for only 1 month. The treatment was well-tolerated. The median (range) follow-up of this case series was of 7 months (6-20), during which all patients maintained a safe platelet count without the need for anti-ITP treatment. The communication of such cases may support the conduction of new studies to investigate which predictive factors could identify ITP patients with sustained responses after discontinuing eltrombopag without additional therapy. The need of long-term use of eltrombopag should be re-examined.

Quality of life in patients with chronic venous disease: influence of the socio-demographical and clinical factors

AIM

Chronic venous disease (CVD) is a well-defined and known disorder which impact on related-health quality of life (QoL). However, individuals factors which determinate quality of life on CVD are not well defined. The purposes of this study were to describe the QoL in patients with CVD and examine socio-demographical and clinical factors which influence QoL METHODS: One thousand five hundred sixty patients with CVD were evaluated. We calculated for each patient two disease-specific severity scores: The "C" grade (clinical) of the CEAP classification and the Venous Clinical Severity Score (VCSS). Additionally, two QoL questionnaires were recorded: Short-Form Health Survey (SF-12) and Chronic Lower Limb Venous Insufficiency Questionnaire (CIVIQ-20). Two multivariate logistic regression analyses (SF-12 and CIVIQ-20 model) were conducted to determine whether demographic and clinical variables were independently associated with QoL.

RESULTS

Both QoL questionnaires indicated that the QoL decreased significantly (P<0.05) as the C grade of CEAP increased. Each increase of 0.10 in VCSS score represented 2% worsening in QoL as measured by CIVIQ-20. Three factors were strongly associated with poor QoL on SF-12: increasing age, prior superficial venous thrombosis (SVT) or prior deep venous thrombosis. In the specific disease CIVIQ-20 questionnaire three factors (higher age, prior SVT and higher weight) were strongly associated with decrease QoL.

CONCLUSION

Increasing disease severity by VCSS is associated with reductions in QoL. Subgroup analysis indicates that there are several significant individual determinants of worsening QoL.

Venous leg ulcer in the context of chronic venous disease

Objectives

Chronic venous disease (CVD) is a frequent disorder with a high socioeconomic impact. Little is known about the possible differences between healed ulcer (C5 group) and active ulcer (C6 group) in terms of disease severity and quality of life (QoL). Our aim was to determine the possible differences in severity disease and QoL between the C5–C6 and C1 (control) group.

Methods

Data from a national, multicentre, observational and cross-sectional study ( n = 1598) were used to compare three groups of CVD: C1 ( n = 243), C5 ( n = 136) and C6 ( n = 70). CVD severity was assessed with the Venous Clinical Severity Score (VCSS) and QoL with the Short Form 12 Health Survey (SF-12) and Chronic Lower Limb Venous Insufficiency Questionnaire (CIVIQ-20).

Results

Patients with active ulcers had a higher mean total VCSS than patients with healed ulcers ( P < 0.05). Both SF-12 and CIVIQ-20 QoL questionnaires indicated a poorer QoL in patients with ulcers than in those with C1 ( P < 0.05). Compared with the C5 group, patients with active ulcers (C6) had lower QoL scores, but the differences were not statistically significant.

Conclusions

Patients with venous leg ulcers (C5–C6) are associated with high severity and poor QoL. However, the healing of a leg ulcer did not contribute to improvement of QoL.

Negative impact of deep venous thrombosis on chronic venous disease

INTRODUCTION

There are several conditions that may cause chronic venous disease (CVD). It is not known whether the aetiology of CVD can predict disease severity and quality of life (QoL). Our objective is that the severity and QoL of patients with CVD secondary to DVT is different from those without prior DVT.

MATERIAL AND METHODS

We compare patients with CVD caused by DVT (n=125) and patients with non-DVT CVD (n=1435) with respect to disease severity (CEAP and Venous Clinical Severity Score-VCSS) and quality of life (Health Survey Short-Form-SF12 y Chronic Lower Limb Venous Insufficiency Questionnaire-CIVIQ20).

RESULTS

Regarding to non-thrombotic CVD, patients with CVD due to DVT showed more severe disease [C6 grade (14.4% vs 3.6%) (p<0.05); score VCSS (1,33±0,65 vs 0,84±0,49) (p<0.05)] and poorer QoL [global score CIVIQ-20 (57,84±15,57 vs 65,75±14,07) (p<0.05); global score SF-12 (45,98±18,79 vs 57,79±19,64) (p<0.05).]. These differences remained statistical significant in all parameters - attributed measured at each severity score and QoL questionnaires.

CONCLUSION

A history of DVT leads to worse clinical severity and quality of life in CVD patients. These data support even more the need to implement programs to prevent DVT and/or its evolutionary consequences.

Risk of placenta-mediated pregnancy complications or pregnancy-related VTE in VTE-asymptomatic families of probands with VTE and heterozygosity for factor V Leiden or G20210 prothrombin mutation

BACKGROUND

Few studies have evaluated the risk of pregnancy-related adverse events in asymptomatic relatives of probands for VTE and factor V Leiden or the G20210A variant. The antepartum management of this population ranges from antepartum anticoagulation therapy to clinical surveillance.

OBJECTIVE

To evaluate the risk of placenta-mediated pregnancy complications and pregnancy-related VTE in VTE-asymptomatic families of probands with VTE and who are heterozygous carriers of either factor V Leiden or PT-G20210A mutation.

METHODS

One hundred and fifty-eight relatives, who had 415 pregnancies, were retrospectively evaluated. Odds ratios and 95% confidence intervals were calculated to compare pregnancy outcomes between women with and without thrombophilia.

RESULTS

In the factor V Leiden group, 22 placenta-mediated pregnancy events of 152 pregnancies (14.4%) were reported, compared with 25 adverse events of 172 pregnancies in the G20210A prothrombin group (14.5%) and 13 adverse events of 91 pregnancies in the non-carrier group (14.2%). Carriers of factor V Leiden or G20210A prothrombin were not associated with a higher risk of pregnancy-adverse outcomes compared with non-carriers: OR 1.02 (95% CI, 0.40-2.25) and 1.25 (95% CI, 0.48-3.24), respectively. Four episodes of pregnancy-associated VTE of 415 pregnancies (0.96%) were recorded. Two episodes of VTE in the G20210A group, one in the factor V Leiden group, and one episode in the non-carrier group were noted.

CONCLUSIONS

In VTE-asymptomatic relatives of probands with VTE, the presence of factor V Leiden or the G20210A prothrombin mutation in heterozygosis should not lead to a decision to instigate antepartum prophylaxis.

Darbepoetin alfa for anemia in patients with low or intermediate-1 risk myelodysplastic syndromes and positive predictive factors of response

BACKGROUND

Current guidelines support the use of erythropoiesis-stimulating agents for the treatment of anemia associated with low-risk myelodysplastic syndromes (MDS).

DESIGN AND METHODS

Single-arm, open-label, multi-center, phase 2 trial that evaluated the efficacy and safety of darbepoetin alfa (DA) in patients with low or intermediate-risk MDS, hemoglobin <100 g/L, erythropoietin (EPO) levels <500 IU/L and transfusion requirements <2 units/month over the preceding 2 months. Erythroid response (major [MaR] or minor [MiR]) and fatigue (Functional Assessment of Cancer Therapy-Fatigue [FACT-F]) were evaluated at 8, 16 and 24 weeks. DA was initiated at 300 μg weekly. For patients who did not achieve MaR by 8 weeks, filgrastim 300 μg weekly was added.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT01039350.

RESULTS

Forty-four patients (72.7% transfusion independent) were included. Median age was 76.0 years (range 41.3-92.4), 54.5% were male, and 90.9% presented ECOG Status (0-1). Eighteen patients received filgrastim. An erythroid response was achieved by 31 of 44 patients (70.5%) at week 8 (47.7% MaR, 22.7% MiR), 31 of 44 patients (70.5%) at week 16 (61.4% MaR, 9.1% MiR), and 32 of 44 patients (72.7%) at week 24 (61.3% MaR, 11.4% MiR). Mean (95% CI) change in FACT-F at week 24 was 3.61 (0.72 to 6.51). Baseline EPO levels <100 IU/L were a predictive factor of response. DA was well tolerated. Four mild (two iron deficiencies, flu syndrome and headache) and one fatal (thromboembolic event) adverse events were considered related to darbepoetin alfa.

CONCLUSIONS

A fixed dose of 300 μg of darbepoetin alfa weekly (with or without filgrastim) seems to be an effective and safe treatment for anemic patients with low or intermediate-risk MDS, low transfusion burden and EPO levels <500 IU/L. Results may not be extrapolable to unselected MDS patients.

CD34?+ cell dose and outcome of patients undergoing reduced-intensity-conditioning allogeneic peripheral blood stem cell transplantation

While in bone marrow allogeneic transplantation the infusion of high doses of progenitor stem cells has a favourable impact on outcome, due to a faster hematopoietic and immune recovery, in the peripheral blood allo-setting the infusion of a high number of CD34 cells increases the risk of extensive chronic graft vs. host disease (cGVHD). This higher incidence of extensive cGVHD has an adverse impact on outcome due to a higher transplant related mortality, specially among patients receiving T-cell depleted allogeneic transplantation with myeloablative conditioning. By contrast, patients undergoing reduced intensity conditioning regimen may benefit from increasing higher CD34 + cell doses, especially those categorized as high risk according to disease status at transplant. Thus, the source of progenitors cells, type of conditioning and GVHD prophylaxis, among other factors, may influence the effect of the progenitor cell dose on outcome after allogeneic transplant.

Peripheral endothelial progenitor cells (CD133 +) for therapeutic vasculogenesis in a patient with critical limb ischemia. One year follow-up

We present a patient with critical limb ischemia who was successfully treated with the injection of autologous peripheral blood (PB) CD133+ purified stem cells (SC) into the gastrocnemius muscle. No serious adverse events related to G-CSF administration, mononuclear cells harvest or CD133+ SC administration was observed. After 17 months of follow-up, our patient has experienced limb salvage, symptomatic relief and functional improvement. Moreover, we have observed the appearance of flow in the right posterior tibial artery that was absent before the procedure. To our knowledge, this is the first case of critical limb ischemia treated with PB CD133+ SC.

Risk of recurrent venous thrombosis in patients with G20210A mutation in the prothrombin gene or factor V Leiden mutation

The impact of the G20210A prothrombin mutation, factor V Leiden and 677T mutation of methylene tetrahydrofalate reductase (MTHFR) in recurrent deep venous thrombosis (DVT) is not so clear. We have prospectively monitored 259 patients following a first episode of DVT in order to determine which factors influence the development of a recurrent event. Several clinical and biological factors together with the genetic polymorphisms of factor V Leiden, G20210A prothrombin and 677T MTHFR were assessed. During a median follow-up of 786 patient-years, 27 patients (14%) developed one objective episode of recurrent venous thrombosis. The carriers of a double defect, homozygous or double heterozygous for factor V Leiden and G20210A, had an increased risk after a first episode of DVT, while patients who were isolated heterozygous for factor V Leiden or G20210 had a risk of recurrent DVT similar to patients who had neither mutation (annual incidence of 12.1, 3.1, 2.9 and 2.8%). The 677T MTHFR mutation alone or combined with hyperhomocysteinemia was not associated with an increased risk of recurrent events. The development of proximal DVT (P=0.01) and the presence of a double defect (P=0.01) were the only two risk factors independently associated with a high recurrence ratio in the multivariate analysis. Thus, the annual incidence of DVT recurrence in patients without any of these two risk factors was only 0.6% (95% confidence interval, 0.2-0.9). We have identified a group of patients with DVT but at very low risk of re-thrombosis in whom an extended secondary thromboprophylaxis should be carefully considered.

Homocysteine and outcome in young patients with acute coronary syndromes

BACKGROUND

Despite the well-known pro-thrombotic and pro-inflammatory plasma homocysteine effects, it remains uncertain whether these effects can be associated with an adverse cardiac outcome in young patients admitted with acute coronary syndromes.

METHODS

Homocysteine levels were determined within 24 h after admission in 244 consecutive patients aged less than 56 years who presented with an acute coronary syndrome. We evaluated the relationship between homocysteine and both short-term (death, myocardial [re]infarction), and long-term prognosis (death, recurrent acute coronary syndrome and/or ischemic stroke), after 3.4+/-1.7 years of follow-up.

RESULTS

Homocysteine levels were similar in patients both with and without in-hospital event: 8.65 (5.36-10.48) vs. 8.98 (7.38-11.13) micromol/l, p=NS. However, patients who presented with the combined event during follow-up had higher homocysteine levels than those free of the event: 10.54 (7.90-11.76) micromol/l vs. 8.52 (7.11-10.23) micromol/l, p=0.001. Patients who either died (13.78 vs. 8.87 micromol/l, p=0.012) or had a myocardial infarction (10.75 vs. 8.76 micromol/l, p=0.006) or unstable angina (10.46 vs. 8.76, p=0.006) during follow-up had higher homocysteine levels. According to the Cox regression analysis: age [hazard ratio 1.05, CI 95%, 0.99-1.10], left ventricular ejection fraction < or =40% [hazard ratio 1.93, CI 95%, 0.98-3.79], and homocysteine tertile 3 [hazard ratio 2.05, CI 95%, 1.13-3.71] were the significant determinants of the combined adverse event during follow-up. Although 41 (18%) of patients presented the TT genotype of the methylen-tetrahydrofolate-reductase thermolabile variant mutation, its occurrence had a neutral effect on morbid-mortality.

CONCLUSIONS

High homocysteine levels at admission strongly predict late cardiac events in young patients with acute coronary syndromes.

Medium-term results of percutaneous vertebroplasty in multiple myeloma

Vertebral compression fractures (VCFs) are common in multiple myeloma (MM). Percutaneous vertebroplasty (PVP) is used to stabilize vertebral collapse and treat the pain. Few studies have been carried out on PVP in MM and follow-up has tended to be short. We have prospectively evaluated the safety and efficacy of PVP in the VCFs resulting from MM or plasmacytomas. Nineteen PVP were performed in 12 consecutive patients. We monitored their pain and functional status using visual analog (VAS) and Eastern Cooperative Oncology Group (ECOG) scale, respectively. For a subjective assessment, every patient was asked about his/her degree of satisfaction. The mean age of the participants was 66 yr. Significant improvement occurred 1 d after PVP according to the VAS score (7.5 pre-PVP to 3.7, P < 0.0001) and ECOG assessment (3.1 to 2.5, P = 0.002). This significant improvement was maintained after 3.2 yr of follow-up. Sixty-three percent of patients were highly satisfied with the result of the PVP and 37% were satisfied. The peri-operative mortality was 0%. Leakage of the cement outside of the vertebral body was noted in 16 of 19 injected vertebrae (84%) but none of the patients developed any clinical or neurological symptoms. At the last follow-up, no further collapse in the treated or neighboring vertebrae was noted. VCFs caused by MM or plasmacytomas can be effectively treated by vertebroplasty. PVP is associated with early clinical improvement of pain and function and can be maintained after a long follow-up without major procedure-related complications.

Quality of life assessment in patients undergoing reduced intensity conditioning allogeneic as compared to autologous transplantation: results of a prospective study

The aim was to analyze quality-of-life (QOL) during the first year post transplant in 47 patients undergoing reduced-intensity conditioning (RIC) allotransplantation, and to compare these with a similar subgroup of patients receiving autologous stem cell transplantation (ASCT). We used self-reported questionnaires. Each answer scored from 0 (not at all) to 4 (very much), with higher scores indicating worse functioning. Mean value of physical categories among RIC transplants ranged between 1.23 and 0.77 indicating that patients scored very low for physical symptoms. Patients undergoing ASCT had higher scores in questionnaires performed early after transplant and then gradually improved (P < 0.001). Overall, when we compared physical functioning scores, allo-RIC did significantly better (P = 0.049). Nevertheless, while allo-RIC scores were significantly better for the first three questionnaires, ASCT patients did better in the last two questionnaires. These findings are in accordance with the toxicities observed in both subgroups which are lower in the RIC group early after transplant. No significant differences were observed between either subgroup for any of the functional, social/ family, psychological distress and satisfaction with doctor/nurse relationship items. We have observed similar QOL among patients undergoing RIC-allo as compared to ASCT although GVHD remains an important 'event' in QOL.