Factor V
Recently Published Documents





2021 ◽  
Vol 16 (1) ◽  
Francesca Di Candia ◽  
Valeria Marchetti ◽  
Ferdinando Cirillo ◽  
Alessandro Di Minno ◽  
Carmen Rosano ◽  

Abstract Background Bleeding anomalies have been reported in patients affected by Noonan syndrome. No study has been performed in patients with molecularly confirmed RASopathy. We aimed to characterize the frequency and types of bleeding disorders in patients with RASopathies and evaluate any significant association with laboratory findings. Patients and methods Forty-nine individuals (PTPN11, n = 27; SOS1, n = 7; RIT1, n = 3; SPRED1, n = 1; LZTR1, N = 3; RAF1, n = 2; BRAF, n = 4; MEK1, n = 1; MEK2, n = 1), and 49 age- and sex-matched controls were enrolled. The “Paediatric Bleeding Questionnaire Scoring Key” was administered to patients and families. Laboratory screening tests including clotting factors dosing, platelet count, Prothrombin Time and Partial Thromboplastin Time, were employed both in patients and controls to characterize the bleeding diathesis. A subgroup of 29/49 patients and 29/49 controls was also tested for platelet function. Results Regardless of the gene involved, pathological paediatric bleeding scores were recorded in 14/49 (28.5%) patients. Indeed, 7 were mutated in PTPN11, 3 in SOS1, 2 in RIT1, 1 in BRAF, and 1 in MEK1. Compared to patients with normal bleeding scores, those with pathologic bleeding score showed higher prevalence of splenomegaly (p = 0.006), prolonged aPTT (p = 0.04), lower levels of coagulation factor V (FV, p = 0.001), FVII (p = 0.003), FX (p = 0.0008) and FXIII (p = 0.002), higher vWAg (p = 0.04), and lower platelet sensitivity to Ristocetin (p = 0.001), arachidonic acid (AA) (p = 0.009) and collagen (p = 0.01). The presence of hematomas inversely correlated with factor V (p = 0.002), factor VII (p = 0.003), factor X (p = 0.002) and factor XIII (p = 0.004) levels, and directly correlated with platelet response to collagen (p = 0.02) and AA (p = 0.01). The presence of splenomegaly directly correlated with the presence of hematoma (p = 0.006), platelet response to Ristocetin (p = 0.04) and AA (p = 0.04), and inversely correlated with factor V levels (p = 0.03). Conclusions Patients with RASopathies and a bleeding tendency exhibit multiple laboratory abnormalities, including platelet-related disorders. Splenomegaly is frequently detected and might be a suggestive sign for qualitative platelet dysfunction. A comprehensive clinical assessment should be carried out at diagnosis, during the follow-up and before any surgical procedures. Since there is currently no consensus on management of bleeding complications, it is important that physicians closely monitor these patients.

Julie A. Peterson ◽  
Sweta Gupta ◽  
Nicholas D. Martinez ◽  
Brandon Hardesty ◽  
Susan A. Maroney ◽  

Healthcare ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1656
Petra Riedlova ◽  
Dagmar Kramna ◽  
Silvie Ostrizkova ◽  
Hana Tomaskova ◽  
Vitezslav Jirik

Background: Thrombophilic mutations in genes for factor V Leiden and factor II prothrombin are among the most important risk factors for developing the thromboembolic disease (TED), along with the use of oral contraceptives (OCs) or smoking. Aim: This study aimed to investigate the occurrence of risk factors in young women using droplet digital PCR (ddPCR) and, based on the results of this investigation, to perform a cost–benefit analysis of ddPCR-based screening in young women starting to take OCs compared to the treatment costs of patients who develop preventable TED in the Czech Republic. Methods: In this cross-sectional study, female university students filled in a questionnaire and provided a blood sample for DNA isolation and ddPCR analysis of both aforementioned genetic risk factors. The results, along with data from literature and web search, were used for cost–benefit analysis valid for the Czech Republic. Results: Out of 148 participants, 30 (20%) were smokers and 49 (33%) took OCs. A mutation was confirmed in 6 women (4.1%) in the factor V gene and in 3 women (2%) in the factor II gene, respectively. A model calculation on a cohort of 50,000 women starting to use contraceptives in the Czech Republic every year showed that at maximum compliance, (i.e., non-use of OC and smoking cessation), screening could prevent 68 cases of TED over the course of the mean period of OC use (5.7 years). Economically, the costs of testing in this cohort (2.25 mil. USD) would be significantly lower than prevented treatment costs (16 mil. USD at maximum compliance); the cost–benefit break-even point would be at 14.1% compliance. Conclusion: The cost–benefit analysis based on our results indicates that screening for factor V Leiden and factor II prothrombin in young women before starting to use OCs would, in the conditions of the Czech Republic, likely be highly economically effective.

Ozlem Oz ◽  
Ataman Gonel

Background: Alterations in erythrocyte morphology parameters have been identified and associated with hematological disorders and other chronic and cardiovascular diseases. Erythrocytes are abundant in thrombus content. Their hemoglobin density and differences in the ratio of macrocytic and microcytic cells may be associated with hypercoagulopathy in those with a history of thrombosis. Objective: This cross-sectional study aimed to investigate the relationship between hemogram parameters and thrombophilia genetic parameters. Method: A total of 55 patients whose thrombophilia panel was reviewed due to the diagnosis of thrombosis were included in the study. %MIC, %MAC, %HPO, %HPR and all hemogram parameters were measured using Abbott Alinity HQ. Prothrombin G20210A, MTHFR C677T, MTHFR A1298C, Factor V Leiden G169A and PAI-1 4G/5G mutations were studied using Real Time-PCR. Results: The MTHFR C677T mutation was detected in 58.2% of the patients. The Factor V Leiden mutation was detected in 5.5% of the patients. The MTHFR A1298C mutation was detected in 58.2%, The PAI mutation was detected in 74.5%, and the Factor 13 mutation was detected in 29% of the patients. Prothrombin G20210A mutation was not detected in any of the patients. Red blood cell (RBC) and Hct values were higher in Factor 13 mutant group; the Hgb and Htc values were higher in the MTHFR C677T mutant group. Conclusion: The MTHFR C677T and Factor 13 mutations may be associated with high Hct and RBC, Hgb, and Htc values, respectively and coagulation tendency in patients with a history of thrombosis.

Anja Maag ◽  
Nienke van Rein ◽  
Tim J. Schuijt ◽  
Wil F. Kopatz ◽  
Danielle Kruijswijk ◽  

Haemophilia ◽  
2021 ◽  
Hsuan‐Yu Lin ◽  
Jen‐Shiou Lin ◽  
Woei Tsay ◽  
Po‐Te Lin ◽  
Ying‐Chih Huang ◽  

Diagnostics ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2071
Ivan E. Wang ◽  
Grant Cooper ◽  
Shaker A. Mousa

With almost 4 million deaths worldwide from the COVID-19 pandemic, the efficient and accurate diagnosis and identification of COVID-19-related complications are more important than ever. Scales such as the pneumonia severity index, or CURB-65, help doctors determine who should be admitted to the hospital or the intensive care unit. To properly treat and manage admitted patients, standardized sampling protocols and methods are required for COVID-19 patients. Using PubMed, relevant articles since March 2020 on COVID-19 diagnosis and its complications were analyzed. Patients with COVID-19 had elevated D-dimer, thrombomodulin, and initial factor V elevation followed by decreased factor V and factor VII and elevated IL-6, lactate dehydrogenase, and c-reactive protein, which indicated coagulopathy and possible cytokine storm. Patients with hypertension, newly diagnosed diabetes, obesity, or advanced age were at increased risk for mortality. Elevated BUN, AST, and ALT in severe COVID-19 patients was associated with acute kidney injury or other organ damage. The gold standard for screening COVID-19 is reverse transcriptase polymerase chain reaction (RT-PCR) using sputum, oropharyngeal, or nasopharyngeal routes. However, due to the low turnover rate and limited testing capacity of RT-PCR, alternative diagnostic tools such as CT-scan and serological testing (IgM and IgG) can be considered in conjunction with symptom monitoring. Advancements in CRISPR technology have also allowed the use of alternative COVID-19 testing, but unfortunately, these technologies are still under FDA review and cannot be used in patients. Nonetheless, increased turnover rates and testing capacity allow for a bright future in COVID-19 diagnosis.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1028-1028
Sergey Zaytsev ◽  
Hyunsook Ahn ◽  
Victoria Stepanova ◽  
M. Anna Kowalska ◽  
Khalil Bdeir ◽  

Abstract Alpha granules in megakaryocytes contain a mixture of endogenously expressed proteins as well as proteins taken up from the intramedullar fluid. Both pools are thought to be found in all alpha granules in the megakaryocytes and released platelets. We have been studying the ectopic expression of urokinase (uPA) in platelets as a targeting strategy for fibrinolysis of nascent thrombi without causing fibrinolysis of established thrombi. These studies also demonstrated that there are two distinct pools of alpha granules, an endogenous cargo pool of granules and an exogenous uptake cargo pool of granules. Using in vitro grown megakaryocytes from two sources (1) CD34+-hematopoietic progenitor cells and (2) induced-pluripotent stem cell derived line imMKCL kindly provided by Dr. Koji Eto at Kyoto University, we demonstrated that urokinase can be localized within alpha granules in the megakaryocytes by either adding urokinase to the media or by ectopically expressing the protein using a lentiviral strategy. We observed that both a human single-chain uPA (scuPA) or a plasmin-insensitive but thrombin-activatable truncated human uPA mutant (uPA-T) in the media were internalized into granules distinct from granules containing ectopically expressed mouse scuPA following lentiviral transduction. Endocytosed uPA showed no co-localization with endogenous von Willebrand Factor (vWF), but significant colocalization with endocytosed Factor V or plasminogen (PLG) on confocal immunofluorescent microscopy. Further, Factor V competed with both uPA variants for uptake from the media. Uptake of these proteins was inhibited by the LRP1 antagonist receptor-associated protein (RAP) and by anti-LRP1 antibodies. This suggests that both proteins use the same endocytic receptor pathway and share this pathway with other proteins taken up from the media, including Factor V. We found that in vitro-generated CD34+ megakaryocytes pre-loaded with exogenously added PLG and co-incubated thereafter with recombinant scuPA and FV significantly degraded FV; however, no vWF degradation was observed in CD34+-derived megakaryocytes that had endocytosed or ectopically expressed scuPA with exogenously added PLG, suggesting that only the proteins which are endocytosed by in vitro-generated megakaryocytes are degraded by uPA-generated plasmin, whereas endogenous alpha-granular proteins remain intact. We then asked whether uPA localized in these two distinct pools can be released at sites of nascent thrombus formation and be effective in preventing nascent thrombus growth. We infused CD34+-derived MKs into NOD-scid IL2rγnull (NSG) mice homozygous for VWF R1326H (a mutation switching binding VWF specificity from mouse to human GPIb/IX). NSG/VWF R1326H mice have impaired clotting after vascular injury compared to NSG mice unless infused with human platelets or MKs . Significantly less post-injury clotting was seen upon infusion of either endogenous or exogenous scuPA-containing MK infusion. Further studies to define relative efficacy at the same levels of scuPA are being pursued. These studies show that there are two sets of alpha granules that remain separate during megakaryopoiesis in vitro: granules with endogenously expressed cargo and granules with endocytosed cargo with limited mixing between the two pools by confocal microscopy studies and following PLG uptake studies. The extent of mixing that occurs subsequently in released platelets was not studied nor has these finding been done with primary MKs not grown in culture; however, we believe that these studies extend our understanding of the nature of alpha granules and offer new insights into how to manipulate their cargo. Disclosures Cines: Dova: Consultancy; Rigel: Consultancy; Treeline: Consultancy; Arch Oncol: Consultancy; Jannsen: Consultancy; Taventa: Consultancy; Principia: Other: Data Safety Monitoring Board.

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3637-3637
Amro Elshoury ◽  
Han Yu ◽  
Wenyan Ji ◽  
James E. Thompson ◽  
Elizabeth A. Griffiths ◽  

Abstract Background: Bleeding and thrombosis are prevalent across all myeloproliferative neoplasm (MPN) subtypes and have significant impact on morbidity and mortality. Although risk factors for thrombosis are well established, bleeding risk factors in these patients are poorly characterized. Identifying MPN patients at higher risk for bleeding could guide the duration of anticoagulation for patients with MPN associated thrombosis (balancing the risk between bleeding and thrombosis), select individuals at higher risk for bleeding during prophylactic anticoagulation, and predict for bleeding complications with surgical procedures. Methods: We performed a retrospective analysis of bleeding risk factors among consecutive adult MPN patients treated at Roswell Park Comprehensive Cancer Center. Bleeding events were classified as minor or major events as defined by the International Society of Thrombosis and Hemostasis (ISTH). The primary outcome of interest was time to initial bleeding after MPN diagnosis. Patient characteristics were summarized as range and medians (for continuous variables) and counts with percentages (for categorical variables) (Table 1). Cox regression was used to examine the associations between candidate risk factors with identified bleeding events in univariate and multivariable analyses. Variables with p<0.1 in univariate analyses were selected for multi-variate analysis. A time-dependent variable of thrombosis status was included in the model. A stepwise feature selection based on Akaike Information Criterion was used for model selection. Continuous variables were dichotomized at median for the regression analyses. Results: A total of 170-consecutive adult MPN patients were identified between 2005 and 2021. Median follow-up was 43.5 months (range 0.66-485.72). The rate of bleeding (major and minor) was 4.9/100 patient-years and rate of thrombosis was 5.4/100 patient-years (5.4/100 patient-years for arterial thrombosis and 2.9/100 patient-years for venous thrombosis). In univariable analysis, predictors of bleeding included age > 60 years (HR 2.8; 95% CI 1.47-5.34; p=0.001), diagnoses of primary myelofibrosis (PMF) (HR 2.98; 95% CI 1.29-6.9; p=0.01) and myelodysplastic syndrome/myeloproliferative neoplasm (MDS-MPN) overlap syndrome (HR 4.56, 95% CI1.91-10.88; p=0.0004), prior history of thrombosis (HR 3.3, 95% CI 1.27-8.8; p=0.01) and presence of ASXL1 (HR 4.13, 95% CI 2.13-8.04; p=0.0001), JAK2 V617F (HR 0.58; 95% CI 0.31-1.08; p=0.08) and TET2 mutations (HR 3.46; 95% CI 1.5-7.9; p=0.003). In multivariate analysis, the presence of JAK2 V617F (HR 4.8; 95% CI 1-21.5; p=0.03) and ASXL1 (HR 12.7, 95% CI 1.7-93; p=0.01) mutations were associated with increased risk of bleeding (Figure 2). Patients with polycythemia vera were at lower risk of bleeding (HR -3.5, 95% CI 0-0.8; p=0.03). Since ASXL1 mutation was associated with a higher risk of bleeding, we studied the association between ASXL1 mutation and other clinical variables. Patients with ASXL1 mutations were more likely to have a diagnosis of PMF and MDS-MPN overlap syndrome (p=0.0001), age > 60 years (p=0.0001), risk for thrombosis (p=0.04), lower hematocrit (p=0.009) and platelets (p=0.0003) but higher white blood cell count (WBC) (p= 0.04) (Figure 3). We then studied the correlation between ASXL1 mutation and factor VIII/Von Willebrand complex and factor V, the two most described abnormal coagulation factors in MPN. ASXL1 mutation was not associated with a statistically significant lower VWF Ag (p=0.07) or factor V (p=0.1) that could potentially explain the higher risk of bleeding seen with this mutation (figure 4). Conclusion: ASXL1 mutations are associated with a significantly higher risk of bleeding in adult MPN patients. The risk of bleeding with ASXL1 mutations was independent of prior thrombosis and was not associated with abnormalities in VWF profile or factor V. Confirmation of these findings in additional patients and studies of underlying platelet function to identify the possible mechanism of ASXL1 associated bleeding in these patients are ongoing. Figure 1 Figure 1. Disclosures Elshoury: Bristol Meyers Squibb: Other: advisory board. Thompson: Novartis/ Bristol-Myers Squibb: Research Funding. Griffiths: Takeda Oncology: Consultancy, Honoraria; Abbvie: Consultancy, Honoraria; Boston Biomedical: Consultancy; Celgene/Bristol-Myers Squibb: Consultancy, Honoraria, Research Funding; Alexion Pharmaceuticals: Consultancy, Research Funding; Novartis: Honoraria; Astex Pharmaceuticals: Honoraria, Research Funding; Taiho Oncology: Consultancy, Honoraria; Apellis Pharmaceuticals: Research Funding; Genentech: Research Funding. Wang: Stemline Therapeutics: Consultancy, Honoraria, Other: Advisory board, Speakers Bureau; Mana Therapeutics: Consultancy, Honoraria; AbbVie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Honoraria, Other: Advisory Board, Speakers Bureau; Novartis: Consultancy, Honoraria, Other: Advisory Board; Kura Oncology: Consultancy, Honoraria, Other: Advisory board, steering committee, Speakers Bureau; Takeda: Consultancy, Honoraria, Other: Advisory board; Jazz Pharmaceuticals: Consultancy, Honoraria, Other: Advisory Board; Kite Pharmaceuticals: Consultancy, Honoraria, Other: Advisory Board; Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; BMS/Celgene: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Consultancy, Honoraria, Other: Advisory Board; DAVA Oncology: Consultancy, Speakers Bureau; Rafael Pharmaceuticals: Other: Data safety monitoring committee; Gilead: Consultancy, Honoraria, Other: Advisory board; Daiichi Sankyo: Consultancy, Honoraria, Other: Advisory board; PTC Therapeutics: Consultancy, Honoraria, Other: Advisory board; Genentech: Consultancy; MacroGenics: Consultancy.

Sign in / Sign up

Export Citation Format

Share Document