scholarly journals Procoagulant Profile in Patients with Immune Thrombocytopaenia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1062-1062
Author(s):  
Nora Butta ◽  
Ihosvany Fernandez Bello ◽  
María Teresa Álvarez Román ◽  
María Isabel Rivas Pollmar ◽  
Miguel Canales ◽  
...  
Keyword(s):  
Platelet Count ◽  
Plasma Concentration ◽  
Thrombin Generation ◽  
Alpha Angle ◽  
Bleeding Risk ◽  
Endothelial Damage ◽  
Healthy Controls ◽  
Platelet Counts ◽  
Spearman Test ◽  
Pai 1

Abstract Background: Patients with platelet counts less than 20 or 30 x 109/L have an increased risk of bleeding. Nevertheless, some patients with immune thrombocytopenia (ITP) have fewer bleeding symptoms than expected. In a previous communication (ASH 2014) we reported that these patients presented high microparticles (MP)-associated procoagulant activity to compensate bleeding risk and that cellular origin of these MPs were platelets and red cells. However, other mechanisms might be involved. Objective: The aim of this work was to analyse the involvement of other factors to compensate bleeding risk in thrombocytopenic ITP patients. Moreover, the feasibility of using the coagulation global assays thromboelastrometry (ROTEM) and Calibrated Automated Thrombogram (CAT) to test haemostasis in these patients was evaluated. Methods: Fifty patients with chronic ITP with platelet count less than 50 x 109/L and twenty-five healthy controls were included. Platelet counts were determined with a Coulter Ac. T Diff cell counter (Beckman Coulter, Madrid, Spain). Citrated blood was centrifuged at 152 g 10 min at 23°C for obtaining platelet rich plasma (PRP) and at 1,500 g for 15 min at 23°C for platelet-poor plasma (PPP) and aliquots were stored at -70ºC until analysis. To assess the kinetics of clot formation, non-activated ROTEM was performed on PRP adjusted to a platelet count of 25 x 109/L. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds], alpha angle, which reflects the rate of fibrin polymerisation (tangent to the curve at 2-mm amplitude [in degrees]), maximum clot firmness,which reflects the maximum tensile strength of the thrombus (MCF, [in mm]) and LI60, which describes the percentage of maximum clot strength present at 60 min (in %), were recorded. Plasma thrombin generation was measured in PPP using the Calibrated Automated Thrombogram (CAT) test at a final concentration of 1 pM tissue factor and 4 mM phospholipids (PPP-Reagent LOW, Thrombinoscope BV, Maastricht, The Netherlands). We evaluated the endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced); and the time to the peak. Fibrinolytic proteins and E-selectin was tested in PPP using commercialized kits. Results were expressed as mean±SD. Comparisons of quantitative variables were made with Mann-Whitney test and correlations with Spearman test. Values of p≤0.05 were considered statistically significant. Results: PRP from ITP patients showed a prolonged CT (control: 550+ 95 sec, ITP: 890+165 sec, p<0.01), diminished alpha angle (control: 62.8+4.3, ITP: 53.5+7.5, p<0.05), and increased MCF (control: 46.7+3.1mm, ITP: 52.4+6.1 mm, p<0.05) and LI60 (control: 90.6+3.0% , ITP: 95.5+3.4, p<0.05) when compared with controls. In order to evaluate whether increased LI60 values were due to an imbalance in fibrinolysis related proteins, tPA, uPA, TAFI and PAI-1 plasma levels were measured. No differences were observed between patients and healthy controls except for PAI-1 which level was increased in ITP patients (control: 14.7 ng/ml+11.7 ng/ml, ITP: 30.4+17.5, p<0.05). Since plasma PAI-1 might be increased as consequence of endothelial damage, plasma concentration of E-selectin, marker of endothelial injury, was determined. E-selectin was increased in samples from ITP patients (control: 10.5 ng/ml+3.9 ng/ml, ITP: 31.6+14.0, p<0.05). Moreover, MCF and LI60 ROTEM parameters correlated to E-selectin plasma concentration (Spearman r values 0.6643, p<0.001 for MCF; 0.6053, p<0.001 for LI60). Thrombin generation in PPP was also measured and a shorter time to peak (control: 9.3+1.2 sec, ITP: 8.3+1.7 sec,p<0.05) and increased ETP (control: 1223.8+257.7 nMxmin, ITP: 1696.4+524 nMxmin,p<0.05) and peak (control: 225.7+82.8.1 nM, ITP: 330.4+106.1 nM,p<0.05) were observed in ITP patients. Conclusions: We demonstrated that ITP patients presented a hypercoagulable profile that might be related, at least in part, to a reduced fibrinolysis mainly caused by an increase in PAI-1 level that seemed to be related to endothelial damage. Moreover ROTEM and CAT appeared to be useful tools for evaluating coagulant profile in ITP patients. Disclosures No relevant conflicts of interest to declare.

Haemostasis in Immune Trombocytopenia Patients Responders to Agonists of Thrombopoietin Receptor

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3743-3743
Author(s):  
Nora Butta ◽  
Ihosvany Fernandez Bello ◽  
María Teresa Álvarez Román ◽  
Monica Martín Salces ◽  
Raul Justo Sanz ◽  
...  
Keyword(s):  
Platelet Count ◽  
Thrombin Generation ◽  
Conflicts Of Interest ◽  
Platelet Rich Plasma ◽  
Alpha Angle ◽  
Bleeding Risk ◽  
Healthy Controls ◽  
Pharmacologic Agent ◽  
Thrombopoietin Receptor ◽  
Pai 1

Abstract Introduction: The goal of treatment of patients with immune thrombocytopaenia (ITP) is to raise platelet count to a level that will minimize or stop bleeding. One of the therapeutic strategies employed is to augment platelet production with agonists of the thrombopoietin receptor (TPOR-A). Clinical trials for TPOR-A comparing their effects with placebo showed a reduction in proportion of patients reporting bleeding (Tarantino et al, Blood Coag Fibrinolysis, 2013, 24:284-296). This effect might rely on the increase in platelet count, but other factors known to compensate bleeding risk in thrombocytopenic ITP patients might be regulated by TPOR-A. Objective: We aimed to compare haemostasis in ITP patients untreated with any pharmacologic agent (UT-ITPp) and treated with TPOR-A (TPOA-Rp) using the coagulation global assays thromboelastrometry (ROTEM®) and Calibrated Automated Thrombogram (CAT). Methods: Thirty chronic UT-ITPp [platelet count: (86±60)x109 platelets/L], twenty six responders to TPOR-A [16 with Romiplostim® and 10 with Revolade®, platelet count: (132±46)x109 platelets/L] and fifty healthy controls were included. Citrated blood was centrifuged at 152 g 10 min at 23°C for obtaining platelet rich plasma (PRP) and at 1,500 g for 15 min at 23°C for platelet-poor plasma (PPP). Aliquots were stored at -80ºC until analysis. Non-activated ROTEM was performed on PRP adjusted to a platelet count of 25 x 109/L. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds], alpha angle, which reflects the rate of fibrin polymerisation (tangent to the curve at 2-mm amplitude [in degrees]), maximum clot firmness, which reflects the maximum tensile strength of the thrombus (MCF, [in mm]) and LI60, which describes the percentage of maximum clot strength present at 60 min (in %), were recorded. Plasma thrombin generation was measured in PPP using the CAT test at a final concentration of 1 pM tissue factor and 4 microM phospholipids. We evaluated the endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced); and the time to the peak. Platelet activation was determined by flow cytometry through PAC1-FITC binding after stimulation with 100 micromol/L thrombin receptor-activating peptide 6 (TRAP). Fibrinolytic proteins were tested in PPP using commercialized kits. Comparisons of quantitative variables were made with SPSS.22 software. Values of p≤0.05 were considered statistically significant. Results: Platelets from all patients with ITP had a defect in their ability to be activated, as shown by the lower PAC1 binding (p<0.001). No differences were observed among groups for thrombin generation except for an increase in ETP in both groups of ITP patients [control: 1240±320 nMxmin, UT-ITPp: 1464±443 nMxmin (p<0.05), TPOA-Rp: 1533±390 nMxmin (p<0.05)]. In ROTEM experiments, PRP from UT-ITPp and TPOA-Rp showed a prolonged CT [control: 550± 95 sec, UT-ITPp: 1090±75 sec (p<0.05), TPOA-Rp: 859±209 sec (p<0.05)]. Only UT-ITPp presented a diminished alpha angle [control: 60.3±7.5, UT-ITPp: 49.3±7.3 (p<0.05), TPOA-Rp: 55.8±5.58]. On the other hand, TPOA-Rp had an increased MCF (control: 46.5±2.1 mm, UT-ITPp: 50.2±5.6 mm, TPOA-Rp: 57.9±4.4 mm, p<0.05) and LI60 (control: 91.8±3.1 %, UT-ITPp: 94.1±3.1 %, TPOA-Rp: 97.6±1.1 %, p<0.05). To evaluate whether increased LI60 values were due to an imbalance in fibrinolysis related proteins, tPA, uPA, TAFI and PAI-1 plasma levels were measured. No differences were observed among the two groups of patients and healthy controls except for PAI-1 which level was increased in TPOA-Rp (control: 12.9±12.3 ng/ml, UT-ITPp: 17.3±12.5 ng/ml, TPOA-Rp: 46.8±20.8, ng/ml p<0.05). Conclusions: As we previously described, TPOR-A treatment increased platelet count but did not ameliorate their function (Álvarez Román et al, Thromb Haemost. 2014, 112:65-72). Nevertheless, ITP patients responders to TPOR-A showed a haemostasis unbalanced on a hypercoagulable profile due, at least in part, to a hipofibrinolytic pattern mainly caused by an increase in PAI-1 plasma level. This fact, together with the increment in platelet count caused by TPOR-A, might help to protect these patients from bleeding. This work was supported by a grant from the FIS-FEDER PI15/01457 Disclosures No relevant conflicts of interest to declare.

Thromboelastometry Shows a Prothrombotic State in Systemic Lupus Erythematosus Related to Diminished Fibrinolysis and Microparticle-Derived Tissue Factor

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2317-2317
Author(s):  
Ihosvany Fernandez Bello ◽  
Francisco Javier López Longo ◽  
Victor Jiménez Yuste ◽  
Miguel Canales ◽  
Juan Ovalles ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Tissue Factor ◽  
Lupus Erythematosus ◽  
Thrombin Generation ◽  
Alpha Angle ◽  
Endothelial Damage ◽  
Hypercoagulable State ◽  
Prothrombotic State ◽  
Systemic Lupus ◽  
Pai 1

Abstract Background: Systemic Lupus Erythematosus (SLE) is an autoimmune disorder of unknown origin with a high mortality pattern due to the development of a premature cardiovascular disease. The presence in these patients of a dysfunctional endothelium together with a hypercoagulable milieu may contribute to an increased incidence of thrombotic events. Increased thrombin generation, elevated levels of circulating microparticles and plasmatic levels of PAI-1 may contribute to the prothrombotic phenotype of the disease but data are scarce. Objectives: 1-To characterize the prothrombotic state in SLE by rotational thromboelastometry (ROTEM) and thrombin generation linked to tissue factor bearing microparticles. 2- To evaluate endothelial damage in patients with SLE and its relationship with the prothrombotic state of the disease. 3- To evaluate the influence of PAI-1 in the prothrombotic state of SLE. Material and methods: 39 patients with SLE and 25 sex and age matched healthy subjects were included. Whole blood was drawn in standard BD sodium citrate tubes (3.2%). ROTEM was performed in naTEM condition. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds], alpha angle, which reflects the rate of fibrin polymerisation (tangent to the curve at 2-mm amplitude [in degrees]), maximum clot firmness, which reflects the maximum tensile strength of the thrombus (MCF, [in mm]), the time that clot takes to increase from 2mm above baseline to 20mm above baseline (CFT) and A5, amplitude at 5 min, were recorded. To evaluate the presence of tissue factor bearing microparticles, thrombin generation was determined by Calibrated Automated Thrombogram (CAT) in presence of 4 mM phospholipid (MP-Reagent, Diagnostica Stago, Spain). The endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced); and the time to the peak were evaluated. Antigenic levels of E-selectin and PAI-1 were determined by ELISA (R&D Systems, MN, USA and Affymetrix eBioscience, Vienna, Austria) respectively. Results: ROTEM parameters showed a hypercoagulable profile in LES patients. CT and CFT were shorter (p<0.001 in both cases), and MCF, alpha angle and A5 were higher (p<0.001, p<0.02 and p<0.001 respectively) when compared to healthy controls. On the other hand, CAT parameters did not show differences between both groups. Nevertheless, in LES patients but not in controls, CAT parameters significantly correlated with ROTEM ones (Table 1). Table 1.Correlations in the LES patients group between CAT and ROTEM parameters. Analyses were performed with Spearman test. N: number of determinations; p* denotes significance.CTCFTMCFMCF-talphaA5A10ETP(MP)r-,301-,375*,369*-,368*,378*,364*,393*p,0840,028*0,031*0,032*0,027*0,034*0,021*N34343434343434Peak(MP)r-,353*-,396*,372*-,345*,396*,393*,402*p0,040*0,020*0,030*0,045*0,020*0,021*0,018*N34343434343434ttPeak(MP)r,240,222-,242,217-,223-,209-,210p,171,207,168,217,205,236,232N34343434343434 In order to evaluate endothelial damage, plasma E-selectin and PAI-1 were determined. No differences were found in E-selectin level whereas increased PAI-1 levels were seen in LES group (p<0.006). PAI-1 did not correlate to ROTEM parameters. Conclusions: ROTEM can detect a hypercoagulable state in patients with SLE. The hypercoagulable state may be linked to increased tissue factor bearing microparticles and increased PAI-1 plasma levels. Disclosures No relevant conflicts of interest to declare.

scholarly journals Haemostasis Impairment in Patients with Myelodysplastic Syndromes with Normal Platelet Counts

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 5225-5225
Author(s):  
Nora Butta ◽  
Monica Martín Salces ◽  
Raquel De Paz ◽  
Ihosvany Fernandez Bello ◽  
María Teresa Álvarez Román ◽  
...  
Keyword(s):  
Platelet Count ◽  
Myelodysplastic Syndromes ◽  
Thrombin Generation ◽  
Alpha Angle ◽  
Clot Formation ◽  
Bleeding Complications ◽  
Control Group ◽  
Healthy Controls ◽  
Normal Platelet Count ◽  
Normal Platelet

Abstract Background: Bleeding complications can have serious outcomes in patients with myelodysplastic syndromes (MDS) and are usually related to thrombocytopaenia. In a recent work we demonstrated that platelets from MDS have impaired capacity to respond to agonist stimulation and exposed more phosphatidylserine (PS) than those from healthy controls whichever their platelet count was (Martin et al, Thromb Haemost., 2013;109:909-19). The exposure of PS in the outer layer of cell membranes supports coagulation through enhanced formation of the tenase (factors IXa, VIIIa and X) and prothrombinase (factors Xa, Va and prothrombin) complexes and thrombin generation. So, the possibility exists that these processes are increased in these patients. Objectives: The aim of this work was to study whether thrombus formation and thrombin generation is impaired in MDS patients with normal platelet count employing global coagulation tests thromboelastrometry (ROTEM) and Calibrated Automated Thrombogram (CAT). Methods: Thirty-one MDS patients with normal platelet count and twenty healthy controls were included. Citrated blood was centrifuged at 152 g 10 min at 23°C for obtaining platelet rich plasma (PRP) and at 1,500 g for 15 min at 23°C for platelet-poor plasma (PPP). For ROTEM and CAT experiments, PRP was adjusted to a platelet count of 25 x 109/L. Aliquots for ROTEM assay were tested within the two hours after obtaining blood samples. For CAT experiments, adjusted PRP and PPP aliquots were stored at -70ºC until analysis. Kinetics of clot formation, non-activated ROTEM was performed on adjusted PRP. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds], alpha angle, which reflects the rate of fibrin polymerisation (tangent to the curve at 2-mm amplitude [in degrees]), and maximum clot firmness, which reflects the maximum tensile strength of the thrombus (MCF, [in mm]), were recorded. Thrombin generation was measured in adjusted PRP without any trigger and in PPP with 1 pM tissue factor and 4 µM phospholipids (PPP-Reagent LOW, Thrombinoscope BV, Maastricht, The Netherlands) as trigger. Endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced); and the time to the peak were evaluated. Platelet activation was determined by PAC1 (BD, Madrid, Spain) binding after stimulation with 100 μM thrombin receptor-activating peptide 6 (TRAP, Bachem, Switzerland) and surface PS through Annexin-V binding and flow cytometry analyses. Results: Platelets from MDS patients had a reduced response to TRAP stimulation (control= 12016+6384 arbitrary units; MDS= 5829+3704 arbitrary units) and exposed more PS than controls (control= 362.1+80.5 MF; MDS= 378.5+173.5 MF). ROTEM experiments showed kinetic parameters corresponding to a hipocoagulable profile (CT: control= 550+95 sec, MDS= 922+216 sec, p<0.01; alpha angle control= 62.8+4.3, MDS= 47.5+6.0, p<0.05; A5: control= 29.8+3.2, MDS= 24.2+5.8, p<0.05 whereas MCF was similar to controls (control= 46.7+3.1mm, MDS= 47.5+4.3 mm). In order to evaluate whether the impaired clot formation was due to a reduction in plasma-associated thrombin generation, CAT experiments were performed in PPP samples. No differences were found between MDS patients and control group (ETP: control=1223.4+257.8 nMxmin, MDS= 1224.4+344 .1 nMxmin; peak: control= 279.5+54.7nM, MDS= 265.9+64.1 nM). On the other hand, when thrombin generation experiments were performed in adjusted PRP, ETP and peak values were lower than in control group (ETP: control=1574.8+430.5 nMxmin, MDS= 1167.4+354 nMxmin,p<0.05; peak: control= 225.6+82.9 nM, MDS= 266.9+92.2 nM, p<0.05). Conclusions: Platelet dysfunction might be resposible of bleeding complications observed in patients with MDS with normal platelet counts. Increment in PS exposure on platelet surface did not seem to compensate impairment in platelet function. Disclosures No relevant conflicts of interest to declare.

scholarly journals Analysis of complete blood counts in rotaviral gastroenteritis with special emphasis on platelet indices

2019 ◽  
Vol 6 (4) ◽  
pp. 1567
Author(s):  
Mahesh B. Maralihalli ◽  
Kavan R. Deshpande ◽  
Pallavi K Deshpande
Keyword(s):  
Platelet Count ◽  
Acute Phase ◽  
Acute Phase Reactant ◽  
Healthy Controls ◽  
Distribution Width ◽  
Platelet Counts ◽  
Rotavirus Gastroenteritis ◽  
Phase Reactant ◽  
Significant Difference ◽  
Complete Blood Counts

Background: The objectives of this study was to analyze complete blood counts in rotaviral gastroenteritis with special emphasis on platelet indices.Methods: Children diagnosed as rotavirus gastroenteritis and healthy controls were enrolled in this study. Severity of acute gastroenteritis was classified into mild, moderate and severe grades using Vesikari score. Rotavirus was determined in fresh stool samples using rapid diagnostic rotavirus antigen test. Hemoglobin, leukocyte, neutrophil to lymphocyte percentage ratio, platelet counts, mean platelet volume (MPV), platelet distribution width (PDW) and platelet crit (PCT) levels were assessed for all children. It’s a case control study conducted at Pediatric Speciality Hospital.Results: There were 30 cases with mean age 1.58 years. Healthy controls were 30 with mean age 2.10 years. Mean Hb was lower in cases. Mean of platelet counts was higher in cases. Mean MPV levels was lower in cases. Mean PCT value was higher in cases. Mean MPV to platelet ratio value was lower in cases. All parameters values showed no significant difference among mild, moderate and severe groups of rotaviral gastroenteritis cases. Platelet count was negatively correlated with Hb, MPVP and positively correlated with TLC and PCT. MPV was positively correlated with MPVP and PDW. PCT was negatively correlated with Hb, MPVP and positively correlated with TLC and platelet count.Conclusions: MPV can be used as negative acute phase reactant in rotavirus gastroenteritis and so is the MPV to platelet ratio. Platelet count is acute phase reactant in rotavirus gastroenteritis and so is the platelet crit value.

Procoagulant Status In Patients With Immune Thrombocytopenia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3528-3528 ◽  
Author(s):  
Ihosvany Fernández Bello ◽  
Mayte Álvarez Román ◽  
Elena G. Arias Salgado ◽  
Monica Martin Salces ◽  
Miguel Canales ◽  
...  
Keyword(s):  
The Netherlands ◽  
Tissue Factor ◽  
Protein C ◽  
Thrombin Generation ◽  
Red Cells ◽  
Procoagulant Activity ◽  
Platelet Counts ◽  
Significant Difference ◽  
The Mean ◽  
Spearman Test

Abstract Introduction Immune thrombocytopaenia (ITP) is an acquired immune-mediated disorder characterized by mild to severe thrombocytopaenia caused by autoantibodies against platelet proteins. Bleeding risk in patients with ITP is increased with platelet counts less than 20 or 30 x 109/L. However, patients with ITP often have few bleeding symptoms despite very low platelet counts suggesting the existence of compensatory mechanisms. Moreover, an increased risk for thrombosis in patients with ITP has been described (Nørgaard M, 2012). It has been recently reported that increased production of platelet- and red cells-derived microparticles (MP) might be one of the causes of increased thrombotic risk in ITP patients (Sewify, 2013). Objective The aim of this study was to evaluate the microparticle-associated and plasma procoagulant activities in ITP patients with thrombocytopaenia. Methods Sixty-eight patients with chronic ITP and platelet count less than 50 x 109/L and twenty-two healthy controls were included. Platelet counts were determined with a Coulter Ac. T Diff cell counter (Beckman Coulter, Madrid, Spain). Citrated blood was centrifuged at 1,500 g for 15 min at 23°C. Platelet-poor plasma obtained was additionally centrifuged twice at 23°C (15 min at 1,500 g, and 2 min at 13,000 g) and aliquots were stored at -70ºC until analysis. Phosphatidylserine-MP (Ph-MP) and tissue factor-MP (TF-MP) dependent procoagulant activities were determined with the ZYMUPHEN kits (Hyphen BioMed, Neuville sur Oise, France) following the manufacturer’s instructions. Plasma thrombin generation was measured using the Calibrated Automated Thrombogram (CAT) test as described by Hemker et al (2000) at a final concentration of 1 pM tissue factor and 4 μM phospholipids (PPP-Reagent LOW, Thrombinoscope BV, Maastricht, The Netherlands). We evaluated the endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced); and the time to the peak. To test resistance to protein C, CAT experiments were performed without and with the addition of thrombomodulin (TM) (PPP and PPP with thrombomodulin reagents, Thrombinoscope BV, Maastricht, The Netherlands). Results were expressed as the ratio [(ETP with TM)/(ETP without ETP)]x100. Results were expressed as mean±SD. Comparisons of quantitative variables were made with Mann-Whitney test and correlations with Spearman test. Values of p≤0.05 were considered statistically significant. Results Ph-MP associated procoagulant capacity in ITP patients was higher than in controls (p<0.05) whereas MP-TF associated procoagulant activity was practically negligible in both groups. Plasma procoagulant activity was higher in ITP patients than in controls (ETP: 1604±616 nM x min in ITP patients and 1302±416, p=0.012 in controls; Peak: 328±123 nM in ITP patients and 203±74 nM in controls, p<0.001). We tested whether the higher procoagulant activity of plasma from ITP patients was due to a resistance to protein C. We observed that the mean Ratio value in ITP patients was slightly higher than the mean Ratio of controls (60±18 and 50±13 respectively, p=0.034). Despite this significant difference in the Ratio, no correlation was found between this value and the CAT parameters. Conclusion ITP patients with thrombocytopaenia had a higher Ph-MP associated and plasma procoagulant activity than controls. The fact that the increased MP-procoagulant activity was not accompanied by a higher TF-MP associated procoagulant activity brings further support to the previous observation that MPs in ITP patients are from platelets and red cells, as both cells express very low levels of TF (Sewify, 2013). Regarding the increased plasma procoagulant capacity observed in ITP patients, our results suggest that resistance to protein C does not seem to be the main mechanism involved. References • Nørgaard M. Thromb Res. 2012;130 Suppl 1:S74-75. • Sewify EM, et al. Thromb Res. 2013;131:e59-63. Hemker HC, et al. Thromb Haemost 2000;83:589-9. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Safety of Lumbar Punctures in Adult Oncology Patients with Thrombocytopenia

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1141-1141 ◽  
Author(s):  
Shuoyan Ning ◽  
Brent Kerbel ◽  
Jeannie Callum ◽  
Yulia Lin
Keyword(s):  
Risk Factors ◽  
Platelet Count ◽  
Platelet Transfusion ◽  
Conflicts Of Interest ◽  
Tertiary Care ◽  
Bleeding Risk ◽  
Von Willebrand Disease ◽  
Oncology Patients ◽  
Platelet Counts ◽  
Hemorrhagic Complications

Abstract Introduction: Lumbar puncture (LP) is a frequently performed diagnostic and therapeutic intervention in adult oncology patients. While thrombocytopenia is common in this patient population, the minimum "safe" platelet count required for LPs is unknown. Recent guidelines from the AABB (American Association of Blood Banks) recommend a pre-procedure platelet count of 50 x 109/L. However this recommendation is largely based on expert opinion, and there remains a paucity of studies in the adult oncology literature to address this important question. Methods: We retrospectively reviewed all oncology patients ≥18 years who underwent 1 or more LPs over a 2 year period at a single tertiary care institution to determine 1) the range of platelet counts at which LPs are performed; 2) the rate of traumatic taps; and 3) the rate of hemorrhagic complications. Laboratory, clinical, and transfusion information were extracted through the Laboratory Information System, chart review, and blood bank database, respectively. Thrombocytopenia was defined as a platelet count of < 150 x 109/L. Pre-LP platelet counts were those collected ≤24 hours from, and closest to the time of the LP. The following bleeding risk factors were documented: end stage renal disease; platelet dysfunction; von Willebrand disease; hemophilia. Anticoagulation, anti-platelet, and non-steroidal inflammatory use was also recorded, with accuracy limited by the study's retrospective nature. All patients with coagulopathy were excluded (INR ≥ 1.5, aPTT ≥ 40, fibrinogen ≤ 1.0). Traumatic tap was defined as 500 or more red blood cells per high-power field in the cerebrospinal fluid. A follow up of 1 week after LP was used to capture any hemorrhagic complications. Results: From January 2013 to December 2014, 135 oncology patients underwent 369 LPs; 64 (47.4%) patients were female, and the mean age was 59 years (range 20-87). 119 (88.1%) patients had a primary hematological diagnosis. 113 (30.6%) LPs were performed in thrombocytopenic patients. 28 (7.6%) procedures had a pre-procedure platelet count of ≤ 50 x 109/L, with 18 receiving a single platelet transfusion on the day of the LP. Of these 18 transfusions, only 1 had a post-transfusion platelet count available prior to LP with no improvement in platelet count (33 x 109/L). 15 transfusions had post-LP platelet counts within 24 hours of the transfusion (8 below 50 x 109/L with lowest 14 x 109/L), 1 had post-LP platelet count within 24-48 hours (54 x 109/L) and 1 did not have a post-transfusion platelet count. Traumatic taps occurred in 17 (15.0%) LPs in patient with thrombocytopenia, compared to 26 (11.0%) LPs in patients with a normal platelet count (fisher's exact test P=0.39). There was 1 traumatic tap in a patient with a pre-LP platelet count of ≤ 50 x 109/L; however, this patient received a pre-LP platelet transfusion for a platelet count of 42 x 109/L and had a post-LP platelet count of 66 x 109/L. Presence of bleeding risk factors did not increase the risk of a traumatic tap (present in 48.8% of traumatic taps vs. 88.3% of non-traumatic taps). There were no hemorrhagic complications. Conclusion: Among this cohort of adult oncology patients undergoing diagnostic and therapeutic LPs, there were no hemorrhagic complications. There was no significant increase in traumatic taps in patients with thrombocytopenia or bleeding risk factors. While platelet transfusions were frequently administered for patients with a platelet count of ≤ 50 x 109/L, post-transfusion platelet counts were infrequently assessed prior to the procedure. Our findings question whether a platelet transfusion threshold of 50 x 109/L is necessary for lumbar puncture.Table 1.Platelet Count Pre-LP(x109/L)Number of LPsNumber of Traumatic TapsNumber of Hemorrhagic Complications0-90N/AN/A10-2030021-5070051-1003380101-1495270> 150242270Unknown1400< 50 x 109/L and received platelet transfusion on day of LP181*0Total369430*There was one traumatic tap in a patient with a platelet count of 42 x 109/L who received a platelet transfusion pre-LP. The post transfusion platelet count was 66 x 109/L. Disclosures No relevant conflicts of interest to declare.

scholarly journals Prothrombotic State, Platelet Activation and Netosis in Systemic Lupus Erythematosus

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1141-1141
Author(s):  
Elena Monzón Manzano ◽  
Ihosvany Fernandez-Bello ◽  
Raul Justo Sanz ◽  
Larissa Valor ◽  
Francisco Javier López-Longo ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Platelet Activation ◽  
Lupus Erythematosus ◽  
Research Funding ◽  
Thrombin Generation ◽  
Hypercoagulable State ◽  
Healthy Controls ◽  
Prothrombotic State ◽  
Systemic Lupus ◽  
Pai 1

Introduction: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease of unknown origin characterized by a hypercoagulable state and a high mortality rate. Mechanisms that cause the accelerated deterioration of cardiovascular health in SLE are unknown. Objectives: to characterize the prothrombotic state in SLE patients by global coagulation assays and the contribution of platelets, endothelial damage, microparticles and neutrophil extracellular traps (NETs) in their prothombotic profile. Material and methods: 72 patients and 90 healthy controls were recruited. Patients were classified according to clinical characteristics in: 32 with lupus (SLE group), 29 with SLE and antiphospholipid antibodies (aFL, SLE+aFL group) and 12 who met the criteria for SLE and antiphospholipid syndrome (APS, SLE+APS group). Experimental protocol was approved by La Paz University Hospital Ethics Committee. Venous blood collected in BD sodium citrate tubes (3.2%) was centrifuged at 150 g for 20 min at 23ºC to obtain platelet-rich plasma (PRP). PPP was obtained by centrifugation at 1500 g for 15 min at 23ºC. To obtain neutrophils, whole blood was centrifuged to 1600 rpm 25 min using a Ficoll gradient and red cells were lysed. Rotational thromboelastometry (ROTEM®) was performed in naTEM condition. Clotting time (CT, time from start of measurement until initiation of clotting [in seconds]); alpha angle (tangent to the curve at 2-mm amplitude [in degrees]), Ax (clot firmness at time x, [in mm]) and maximum clot firmness (MCF, [in mm]) were recorded. Procoagulant activity associated to microparticle's content of tissue factor was determined in PPP by Calibrated Automated Thrombogram (CAT) using MP-reagent (4 mM phospholipids, Diagnostica Stago, Spain). We evaluated the endogenous thrombin potential (ETP, the total amount of thrombin generated over time); the lag time (the time to the beginning of the explosive burst of thrombin generation); the peak height of the curve (the maximum thrombin concentration produced) and the time to the peak. Thrombin generation associated to NETs was also measured by CAT. Neutrophils from healthy controls or from LES patients were stimulated with 100 nM PMA in RPMI medium during 45 min at 37º and then cocultivated with PRP adjusted to 105 platelets/µL. NETs formation was verified by fluorescent microscopy performed with DAPI and an anti-myeloperoxidase antibody. Plasma levels of LDL-ox, E-Selectin and PAI-1 were determined by Elisa (R&D Systems, MN, USA and Affymetrix eBioscience, Vienna, Austria, respectively). Platelet activation was analysed by flow cytometry (FCM, FACScan, BD Biosciences). Fibrinogen receptor activation was evaluated through PAC1-FITC binding and release of granule's content was assessed with monoclonal antibodies (mAbs) anti-CD63 and anti P-selectin in quiescent and 100 µM TRAP and 10 µM ADP stimulated platelets. Data were analysed with Graphpad prism and p ≤0.05 was stablished as statistical significance. Results: PAI-1 plasma level was increased in all patient's groups, whereas LDL-ox and E-selectin showed no differences with control cohort (Fig.1). ROTEM demonstrated a procoagulant profile in SLE and SLE+aPL but not in SLE+APS group (Fig. 2). PAI-1 levels correlated with several ROTEM parameters (Table 1). SLE patients and SLE+aFL showed a basal platelet activation. Moreover, SLE group exposed more P-selectin and CD63 than controls (Fig.3). Regarding thrombin generation associated to tissue-factor content of microparticles, no differences were observed between SLE patients and healthy controls. On the other hand, SLE patients had an increased peak of thrombin generation related to NETs formation (control group: 170.3± 58.0, SLE patients: 230.6±39.3, p=0.019). Conclusions: ROTEM® detected a hypercoagulable state in SLE and SLE+aPL patients. The hypercoagulable state might be linked to increased PAI-1 plasma levels and basal platelet activation in SLE and SLE+aPL groups. Moreover, neutrophils from SLE patients seemed to present a basal activation that induced a NETs-related procoagulant state in these patients. SLE+APS patients did not show a hypercoagulable state perhaps because of the presence of lupus anticoagulant and/or to therapeutic treatment of these patients. This work was supported by grants from the FIS-FONDOS FEDER (PI15/01457, NB). NVB holds a Miguel Servet tenure track grant from FIS-FONDOS FEDER (CP14/00024). Disclosures Fernandez-Bello: Novartis, Pfizer, ROCHE, Stago: Speakers Bureau. Robles:ABBVIE, SANDOZ FARMACEUTICA: Speakers Bureau. Álvarez Roman:Sobi: Consultancy, Speakers Bureau; CSL Behring: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; Pfizer: Consultancy, Speakers Bureau; Bayer: Consultancy, Speakers Bureau; Novartis: Consultancy, Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Takeda: Research Funding; NovoNordisk: Consultancy, Speakers Bureau. Canales:Celgene: Honoraria; Gilead: Honoraria; Novartis: Honoraria; Janssen: Honoraria, Speakers Bureau; Sandoz: Honoraria; iQone: Honoraria; Takeda: Speakers Bureau; SOBI: Research Funding; Karyopharm: Honoraria; F. Hoffmann-La Roche Ltd: Honoraria, Speakers Bureau. Jimenez-Yuste:Bayer, CSL Behring, Grifols, Novo Nordisk, Octapharma, Pfizer, Roche, Sobi, Shire: Consultancy, Honoraria, Other: reimbursement for attending symposia/congresses , Research Funding, Speakers Bureau. Butta:Novartis: Consultancy; Roche, Pfizer: Speakers Bureau.

Abstract 568: Biomarkers of Hemostasis and Thrombosis in Hemophilia A and B Patients

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Zhu Chen ◽  
Weizhen Wu ◽  
Lan Ge ◽  
Marina Ichetovkin ◽  
Kunal Desai ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Thrombin Generation ◽  
Hemophilia A ◽  
Platelet Reactivity ◽  
Statistical Significance ◽  
Vascular Inflammation ◽  
Bleeding Risk ◽  
Strong Positive Correlation ◽  
Pai 1

The defective hemostatic process in hemophiliacs overlaps with the underlying physiology contributing to bleeding risk in anticoagulated patients. Hemophiliacs may also develop compensatory changes in fibrinolysis, platelet reactivity, vascular inflammation, and remodeling secondarily. We therefore explored markers for these processes in hemophilia A and B as part of our larger effort to develop translational biomarkers to guide antithrombotic therapy and minimize bleeding risk. Plasmas from hemophilia A patients (11 severe; 1 moderate) and hemophilia B patients (3 severe; 3 mild or moderate), sampled after a treatment washout period, and 7 normal subjects were procured. Markers/assays pursued include: coagulation (F1+2, FPA, TAT, D-dimer), fibrinolysis (PAP, PAI-1, tPA), platelet activation (soluble P-selectin (sP-sel)), vascular inflammation (MCP-1), angiogenesis (VEGF), PT, aPTT, and thrombin generation assay (TGA). Consistent with aPTT prolongation and changes in TGA, both hemophilia groups displayed numerically lower than normal levels of all 4 coagulation markers, with hemophilia A reaching statistical significance for F1+2 and TAT. Hemophilia A also exhibited a significant decrease in PAP and a numerical increase in PAI-1 compared to normal. VEGF and MCP-1 exhibited no appreciable difference. In the combined analysis for hemophilia A and B (“A+B”), PAP displayed a strong positive correlation with F1+2 and a strong negative correlation with PAI-1; A+B exhibited a statistically significant reduction in F1+2, FPA, and TAT, and a non-significant increase in sP-sel and non-significant decrease in PAP, compared to normal. In conclusion, hemophilia A and B plasma samples had significantly reduced markers of in vivo thrombin generation, thrombin activity, and coagulation, and trends evidencing increased platelet activation and decreased fibrinolysis, possibly as compensation. Lack of signal in vascular inflammation or angiogenesis could be due to the (near optimal) hemostatic therapies. Our results illustrate the potential value of biomarkers of in vivo coagulation, fibrinolysis, and platelet activation in translational research on antithrombotic therapies for both their efficacy and bleeding risk.

scholarly journals Platelet Apoptosis and PAI-1 Content Are Involved in the Procoagulant Profile of Immune Thrombocytopenia Patients Responders to Agonists of Thrombopoietin Receptor.

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3738-3738
Author(s):  
Raul Justo Sanz ◽  
Elena Monzón Manzano ◽  
Ihosvany Fernandez-Bello ◽  
Teresa Álvarez-Roman ◽  
Mónica Martín ◽  
...  
Keyword(s):  
Research Funding ◽  
Immune Thrombocytopenia ◽  
Alpha Angle ◽  
Clot Formation ◽  
Clot Lysis ◽  
Control Group ◽  
Healthy Controls ◽  
Prothrombinase Complex ◽  
Thrombopoietin Receptor ◽  
Pai 1

Abstract Background: The treatment goal for patients with immune thrombocytopenia (ITP) is to raise platelet counts to levels that minimize or stop bleeding. Thrombopoietin receptor agonists (TPO-RAs) have been successfully and extensively employed as second-line therapy for ITP. TPO-RAs, however, have a small but significant increase in the risk of thrombosis. Aim: The aim of this study was to elucidate the mechanisms involved in the procoagulant effect of TPO-RAs. Methods: This is a prospective, observational and transversal study. Eighty-two patients with chronic primary ITP, 40 without treatment for at least six months (UT-ITP) and 42 responders to TPO-RA therapy (64.3% with eltrombopag and 35.7 % with romiplostim) were recruited. One hundred and twelve healthy participants were also included. ROTEM® (naTEM test: only recalcification) was performed on platelet rich plasma adjusted to a platelet count of 25 x 109/L. Clotting time (CT, time from start of measurement until 2 mm of amplitude [in seconds], alpha angle, which reflects the rate of fibrin polymerisation (tangent to the curve at 2 mm amplitude [in degrees]), maximum clot firmness, which reflects the maximum tensile strength of the thrombus (MCF, [in mm]) and LI60, which describes the percentage of maximum clot strength present at 60 min (in %), were recorded. Surface exposure of phosphatidylserine (PS), active caspase-3, -8 or -9 and prothrombinase complex binding to platelets were assessed by flow cytometry. Plasma and platelet levels of PAI-1 were determined by ELISA (eBioscience Ltd., Hatfield, United Kingdom). The effect of TPO and romiplostim on PAI-1 content of MEG-01 cells was evaluated by Western blot. Three MEG-01 cell cultures were initiated simultaneously: control without drugs and treated with either TPO (100 ng/mL) or romiplostim (53 μg/mL). Samples were collected at the start and after 24, 48 and 72 hours to determine the PAI-1 content. The statistical analysis was performed using SPSS 9.0 software (SPSS Inc., Chicago, Illinois, USA). Results: The ROTEM® studies showed significant differences in the dynamics of clot formation when comparing the control with ITP samples. There was a delay in clot formation in the UT-ITP group, as observed by a prolonged CT [expressed as median (p25-p75): control: 516 (490- 633) s; UT-ITP: 938 (914-1348) s, p<0.001], and a diminished alpha angle (mean±SD; control: 61.7±5.6 degrees; UT-ITP: 49.2±7.3 degrees, p<0.05). Nevertheless, samples from patients with UT-ITP reached the same MCF as those from healthy controls (control: 45.3±2.4 mm; UT-ITP: 46.9±3.7 mm). On the other hand, patients with ITP undergoing TPO-RA therapy presented an initial clot formation similar to that of the control group [expressed as median (p25-p75): CT, 672 (598-928) s; alpha angle, 55.8±5.8 degrees] but achieved a higher MCF (53.1±4.5 mm, p<0.05) and a reduced clot lysis after 60 min (control: 91.8±4.0%; UT-ITP: 93.7±4.0%, TPO-RA ITP: 97.6±1.7, p<0.05). Higher values of MCF observed with platelets from ITP patients treated with TPO-RAs might be a consequence of their augmented apoptosis signs: platelets from this group exposed more PS than controls and this situation was accompanied by an increased activity of caspases-3,7, -8 and -9 (Figure 1 A and B). Moreover, platelets from ITP patients on treatment with TPO-RAs bound more prothrombinase complex than platelets from UT-ITP patients and healthy controls (Figure 1 C). Reduced clot lysis observed in ITP patients treated with TPO-RA was due, at least in part, to increased plasma and platelet levels of PAI-1 (Table 1). Increase in platelet content of PAI-1 might be the result of the effect of TPO-RAs during megakaryopoiesis since treatments of MEG-01 cells with TPO or romiplostim induced a 3-fold increase in their endogenous PAI-1 content after an incubation period of 48 hs. Conclusion: The patients with ITP undergoing TPO-RAs therapy presented a procoagulant profile due to the formation of a more fibrinolysis-resistant clot because of increased platelet and plasma PAI-1 levels. Moreover, platelets from this group of patients showed more signs of apoptosis that causes a higher exposure of PS and, consequently, a larger surface for the binding of the prothrombinase complex. Work supported by grant from FIS-FEDER PI15/01457. NB holds a Miguel Servet II (FIS-FEDER CP14/00024). Disclosures Álvarez-Roman: SOBI: Consultancy; NovoNordisk: Consultancy; Shire: Consultancy. Jimenez-Yuste:Grifols: Consultancy, Research Funding; Octapharma: Consultancy, Research Funding; CSL Behring: Consultancy; Bayer: Consultancy, Research Funding; Roche: Consultancy, Research Funding; Shire: Consultancy, Research Funding; Sobi: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; NovoNordisk: Consultancy, Research Funding. Butta:FIS-Fondos FEDER: Research Funding.

Effects Of Thrombopoietin Receptor Agonists On APRIL Plasma Levels In Patients With Immune Thrombocytopenia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1083-1083
Author(s):  
Nora V. Butta ◽  
Mayte Álvarez Román ◽  
Ihosvany Fernández Bello ◽  
Elena G. Arias Salgado ◽  
Isabel Rivas Pollmar ◽  
...  
Keyword(s):  
Platelet Count ◽  
T Cell ◽  
Regulatory T Cell ◽  
Plasma Levels ◽  
Immune Thrombocytopenia ◽  
Cell Activity ◽  
Healthy Controls ◽  
Platelet Counts ◽  
Chronic Itp ◽  
Thrombopoietin Receptor

Abstract Introduction Immune thrombocytopenia (ITP) is an example of an autoimmune disease in which B-lymphocytes produce autoantibodies against platelets. Antibody-mediated platelet destruction and suboptimal platelet production leads to a decrease in platelet count. ITP patients with thrombocytopaenia have increased plasma levels of a proliferation-inducing ligand (APRIL), a factor that can promote B-cell maturation and survival. Two new compounds that bind to the thrombopoietin receptor (TPO-R) and activate the megakaryopoiesis have been recently approved for the treatment of chronic ITP as second-line treatment. Objective It has been recently reported an improved regulatory T-cell activity in patients with chronic ITP treated with TPO-R agonists (TPO-RA) (Bao et al, 2010). So we aimed to evaluate the effect of TPO-RA treatment on APRIL plasma levels in ITP patients before (ITP-1) and after responding (ITP-2) to the treatment. Methods This was an observational and prospective study. Thirteen patients with chronic ITP in whom treatment with a TPO-RA was indicated, and thirty-three healthy controls were included. ITP patients were studied at two times: at inclusion (ITP-1), when platelet count was less than 30x109/L for patients without concomitant medication or less than 65x109/L for patients receiving corticosteroids or intravenous immunoglobulin; and after a response to TPO-RA therapy was elicited (ITP-2). The response to TPO-RA was defined as a platelet count >30x109/L in patients without additional treatment or >65x109/L for those with concomitant treatments. EDTA-anticoagulated whole blood was centrifuged at 1,500 g for 15 min at 23°C to obtain platelet poor plasma which was then centrifuged at 10,000 g for 15 min at room temperature. Supernatant plasma was stored at –70°C until analysis. Plasma TPO and APRIL concentrations were determined using a commercially available enzyme-linked immunosorbent assay (ELISA, Duoset-R&D, Minneapolis, Mn, USA). Platelet counts were determined with a Coulter Ac. T Diff cell counter (Beckman Coulter, Madrid, Spain). Comparisons of quantitative variables were made with ANOVA and Dunn test. Results were expressed as mean±SD. Correlations were calculated with Spearman test. Values of p≤0.05 were considered statistically significant. Results Platelet count in the ITP-1 group ((23±17)x109/L) increased after responding to TPO-RA to values similar to controls (controls: (233±77)x109/L and ITP-2: (140±36)x109/L). TPO plasma level was higher in ITP-1 patients (30.05±26.81 pg/ml, p<0.005) than in healthy controls (7.36±11.74 pg/ml) but not significantly different when compared with the values of the ITP-2 group (26.81±17.62 pg/ml). ITP-1 patients showed significantly higher APRIL plasma levels (37.60+28.73 ng/ml, p<0.0001) than controls (2.20±3.11 ng/ml) and ITP-2 patients (4.92+4.68 ng/ml), indicating that TPO-RA treatment caused a diminution in APRIL plasma levels. When looking into the relationship between APRIL plasma levels and platelet count, a significant correlation was only found in the ITP-1 group (r=-0.5919, p<0.05). This supports the potential role of APRIL in the reduction of platelet counts in ITP patients. Conclusion ITP patients with thrombocytopaenia that responded to TPO-RA treatment increased their platelet count reducing plasma APRIL levels and without changing the moderately high levels of plasma TPO. Reductions in APRIL levels caused by TPO-RA treatment could be an additional mechanism that contributes to an increased platelet count in ITP patients treated with these agents. Bao W, Bussel JB, Heck S, et al. Improved regulatory T-cell activity in patients with chronic immune thrombocytopenia treated with thrombopoietic agents. Blood. 2010 Nov 25;116(22):4639-4645 Disclosures: No relevant conflicts of interest to declare.

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