Two Independant Assays Demonstrate High Phospholipid Procoagulant Activity In Poor Platelet Plasma of Sickle Cell Disease Children.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1630-1630
Author(s):  
Alina Ferster ◽  
Denis fondjie Noubouossie ◽  
Anne C Demulder ◽  
Francis V. Corazza ◽  
Phu-Quoc Le
Keyword(s):  
Steady State ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Specific Treatment ◽  
Positive Control ◽  
Procoagulant Activity ◽  
Hypercoagulable State ◽  
Clinical State ◽  
Cell Disease ◽  
Normal Controls

Abstract Abstract 1630 Sickle cell disease (SCD) is considered as a hypercoagulable state through still a mechanism poorly understood. Our hypothesis is that poor platelet plasma (PPP) from SCD children may contain a high phospholipids procoagulant activity. This study aimed 1° at using and comparing two different assays to detect the procoagulant activity of endogenous phospholipids (ePL) in the PPP of SCD children in steady state compared to normal controls, 2° at assessing the influence of the clinical state and treatment on this procoagulant activity. Patients: A group of 30 SCD children aged between 2 – 20 years (median=9, 16 males, 14 females) were studied: 12/30 didn't receive any specific treatment, 6/30 were chronically transfused (TRX) and 12/30 were treated by hydroxyurea (HU). 11/30 were previously admitted because of a vaso-occlusive crisis (VOC). 24 SCD patients were HbSS, 4 HbSC, and 2 HbSβ. Controls: 18 remaining samples from children aged between 3 – 20 years (median=9, 11 males, 7 females) undergoing minor elective surgery, with no history of coagulation disorder, normal routine coagulation tests, normal CRP, liver and kidney functions tests. The controls were not matched for the age neither sex. Venous blood was collected into 0,109M citrated tubes using a 23G butterfly needle. PPP was obtained after 2 steps of centrifugation (3200g for 15 min and 16000g for 2 min) within 2 hours following venipuncture, and stored at -80°C. Procoagulant activity of ePL was assessed using two independent assays: a commercial fully automated factor Xa-based clotting time assay (XACT: sec) as described by Exner et al (ProcoagPPL® Stago, Asnières sur Seine, France), and a thrombin generation assay (TGA) using calibrated automated thrombinography (CAT) as described by Hemker et al (Thrombinoscope®, Maastricht, The Netherland). TGA was triggered with 10pM tissue factor (TF) alone and with a combination of 10pM TF and 4μM synthetic PL (positive control). Four TGA parameters were analysed: lag time (LT), Peak, Velocity Index (VI) and Endogenous Thrombin Potential (ETP). For each parameter, the result was also expressed as a % of the positive control, to minimize the influence of age. Correlations were assessed between XACT and TGA parameters using the Spearman's coefficient. Group comparison was assessed using non parametric tests. Significant correlations were found between XACT and Peak (r= -0,76, p<0,0001), VI (r= -0,73, p<0,0001), ETP (r= -0,47, p<0,0001) measured without addition of PL, and also between XACT and % Peak (r= -0,73, p<0,0001), %VI (r= -0,63, p<0,0001) and % ETP (r= -0,60, p<0,0001). No correlation was found between XACT and LT (r= 0,20, p = 0,096). The table shows median and range values obtained from SCD patients in steady state as compared to those of normal controls, using both methods. The TGA values are those obtained with 10pM alone, and are also expressed as a percentage of positive control. Concerning the clinical state and treatment, XACT and all CAT parameters failed to show significant differences between subgroups of SCD (steady vs. CVO, n=11), and their treatment (TRX vs. HU vs. No specific treatment). For the patients undergoing chronic exchange transfusion, no significant difference was observed between the samples collected before and few hours after transfusion exchange. In SCD children in steady state, XACT is significantly shortened compared to normal controls. Velocity index and Peak thrombin are significantly increased when using a high TF concentration alone as trigger. Each test showed similar performance to detect a higher procoagulant activity of ePL in SCD patients, which could contribute to the hypercoagulable state observed in those patients. In our study, ePL procoagulant activity was not influenced by the clinical state, neither the type of treatment, but this could be due to the relatively small number of patients included till now. We are currently studying more patients to confirm our results in a larger group and in particular to analyze the effects of treatment. Disclosures: Noubouossie: Belgian Kid's Fund: Grant's recipient of the Belgian Kid's Funds.

Constitutive Activation of Hemostasis in Children with Sickle Cell Disease.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1216-1216
Author(s):  
MacGregor Steele ◽  
Suzan Williams ◽  
Fred Pluthero ◽  
K.W. Annie Bang ◽  
Ran Goldman ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Steady State ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Whole Blood ◽  
Surface Expression ◽  
Hypercoagulable State ◽  
Cell Disease ◽  
Normal Children

Abstract Recent studies of sickle cell disease (SCD) suggest that hemostatic activation is a key aspect of pathophysiology, leading to clinical consequences such as vaso-occlusive crises and stroke. In many of these studies a SCD-associated hypercoagulable state has been inferred from markers suggestive of increased hemostatic activity, such as elevated levels of plasma thrombin-antithrombin complexes and tissue factor-containing microparticles. As part of a study using a broad-spectrum approach to explore the relationships among various aspects of normal and abnormal hemostasis in SCD we used a whole-blood coagulation assay (thromboelastography, TEG) to directly assess global hemostatic activation in children with SCD defined by genotype (SS and SC), together with a group of unaffected children. We also assessed platelet activation and procoagulant surface expression in platelets and red blood cells (RBCs) using flow cytometry. Eligible SCD subjects included:patients with painful crisis assessed at two time points: hospital admission (crisis group) and clinic follow-up appointment (follow-up group);patients not in crisis attending a regular clinic appointment (steady-state group). Patients were ineligible if they had received a recent blood transfusion, hydroxyurea, anticoagulants or aspirin. The results of TEG assays with citrated whole blood showed that compared to SC patients (n = 16) and normal children (n = 16), SS patients (n = 45) had significantly (p&lt;0.001) earlier clotting onset (mean R times were 4.5, 6.5 and 7.6 minutes for SS, SC and normals respectively) and significantly (p&lt;0.001) higher rates of clotting (mean maximum clotting rates were 16.8, 12.6 and 10.9 mm/min for SS, SC and normals respectively). TEG clotting onset and maximum clotting rates were not significantly different among steady-state, crisis and follow-up groups of children with SCD (both SS and SC genotypes), nor between sexes within each study group. Whole blood flow cytometry revealed that platelet GPIIb/IIIa activation (PAC-1 binding) was significantly elevated (p&lt;0.05) in SCD patients relative to normal children. In addition, markers of RBC procoagulant surface expression (RBC annexin A5 binding) and RBC-platelet aggregates were elevated in SCD patients compared to normal children. These results indicate that children with the SS genotype have an activated hemostatic system relative to normal and SC genotype children, and that this hypercoagulable state is maintained during sickle cell crisis as well as during steady state. It remains to be determined whether pharmacological interventions and/or RBC transfusions which improve clinical outcomes in SCD patients modify their constitutively hypercoagulable state.

Increased Procoagulant Activity of Red Blood Cells from Patients with Homozygous Sickle Cell Disease and β-Thalassemia

1996 ◽  
Vol 76 (03) ◽  
pp. 322-327 ◽  
Author(s):  
Dominique Helley ◽  
Amiram Eldor ◽  
Robert Girot ◽  
Rolande Ducrocq ◽  
Marie-Claude Guillin ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Red Blood Cells ◽  
Sickle Cell ◽  
Blood Cells ◽  
Annexin V ◽  
Mean Value ◽  
Procoagulant Activity ◽  
Dependent Manner ◽  
Cell Disease ◽  
Homozygous Sickle Cell Disease

SummaryIt has recently been proved that, in vitro, red blood cells (RBCs) from patients with homozygous β-thalassemia behave as procoagulant cells. The procoagulant activity of β-thalassemia RBCs might be the result of an increased exposure of procoagulant phospholipids (i. e. phosphatidylserine) in the outer leaflet of the membrane. In order to test this hypothesis, we compared the catalytic properties of RBCs of patients with β-thalassemia and homozygous sickle cell disease (SS-RBCs) with that of controls. The catalytic parameters (Km, kcat) of prothrombin activation by factor Xa were determined both in the absence and in the presence of RBCs. The turn-over number (kcat) of the reaction was not modified by normal, SS- or (3-thalassemia RBCs. The Km was lower in the presence of normal RBCs (mean value: 9.1 µM) than in the absence of cells (26 µM). The Km measured in the presence of either SS-RBCs (mean value: 1.6 µM) or β-thalassemia RBCs (mean value: 1.5 pM) was significantly lower compared to normal RBCs (p <0.001). No significant difference was observed between SS-RBCs and p-thalassemia RBCs. Annexin V, a protein with high affinity and specificity for anionic phospholipids, inhibited the procoagulant activity of both SS-RBCs and (3-thalassemia RBCs, in a dose-dependent manner. More than 95% inhibition was achieved at nanomolar concentrations of annexin V. These results indicate that the procoagulant activity of both β-thalassemia RBCs and SS-RBCs may be fully ascribed to an abnormal exposure of phosphatidylserine at the outer surface of the red cells.

scholarly journals Neutrophil gelatinase–associated lipocalin as a biomarker of nephropathy in sickle cell disease

2021 ◽  
Author(s):  
Rajaa Marouf ◽  
Adekunle D. Adekile ◽  
Hadeel El-Muzaini ◽  
Rasha Abdulla ◽  
Olusegun A. Mojiminiyi
Keyword(s):  
Steady State ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Roc Curve ◽  
Screening Tests ◽  
Cell Disease ◽  
Urine Ngal ◽  
Neutrophil Gelatinase Associated Lipocalin ◽  
Plasma Ngal ◽  
Neutrophil Gelatinase

AbstractSickle cell nephropathy (SCN) develops via altered hemodynamics and acute kidney injury, but conventional screening tests remain normal until advanced stages. Early diagnostic biomarkers are needed so that preventive measures can be taken. This study evaluates the role of neutrophil gelatinase–associated lipocalin (NGAL) as a biomarker of SCN in steady state and vaso-occlusive crisis (VOC). In this case-control study, 74 sickle cell disease (SCD) patients (37 in steady state and 37 in VOC) and 53 control subjects had hematological and biochemical measurements including plasma and urine NGAL. Univariate and logistic regression analyses were used to find the associations between variables. The receiver operating characteristic (ROC) curve was used to determine the diagnostic performance characteristics of plasma and urine NGAL for detection of VOC. Plasma and urine NGAL, urine microalbumin:creatinine ratio, and urine protein:creatinine ratio were significantly higher in VOC. Microalbuminuria was present in 17.1% steady state and 32.0% VOC patients. Microalbuminuria showed significant correlations with age, plasma NGAL, WBC, and hemolytic parameters. Area under the ROC curve for plasma NGAL was 0.69 (95%CI = 0.567–0.813; p = 0.006) and 0.86 (95%CI = 0.756–0.954; p < 0.001) for urine NGAL. Urine NGAL cut-off value of 12.0 ng/mL had 95% sensitivity and 65% specificity. These results confirm the presence of nephropathy during VOC and suggest that plasma and urine NGAL would be useful in the identification of SCN. Urine NGAL should be used as the screening biomarker, and patients with VOC and urine NGAL > 12.0 ng/mL should be selected for aggressive management to prevent progression of renal damage.

scholarly journals Effects of Genotypes and Treatment on Oxygenscan Parameters in Sickle Cell Disease

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 811
Author(s):  
Camille Boisson ◽  
Minke A. E. Rab ◽  
Elie Nader ◽  
Céline Renoux ◽  
Celeste Kanne ◽  
...  
Keyword(s):  
Steady State ◽  
Sickle Cell Disease ◽  
Blood Cell ◽  
Sickle Cell ◽  
Red Blood Cell ◽  
Cell Disease ◽  
Oxygen Gradient ◽  
Acute Complication ◽  
Adults And Children ◽  
The Difference

(1) Background: The aim of the present study was to compare oxygen gradient ektacytometry parameters between sickle cell patients of different genotypes (SS, SC, and S/β+) or under different treatments (hydroxyurea or chronic red blood cell exchange). (2) Methods: Oxygen gradient ektacytometry was performed in 167 adults and children at steady state. In addition, five SS patients had oxygenscan measurements at steady state and during an acute complication requiring hospitalization. (3) Results: Red blood cell (RBC) deformability upon deoxygenation (EImin) and in normoxia (EImax) was increased, and the susceptibility of RBC to sickle upon deoxygenation was decreased in SC patients when compared to untreated SS patients older than 5 years old. SS patients under chronic red blood cell exchange had higher EImin and EImax and lower susceptibility of RBC to sickle upon deoxygenation compared to untreated SS patients, SS patients younger than 5 years old, and hydroxyurea-treated SS and SC patients. The susceptibility of RBC to sickle upon deoxygenation was increased in the five SS patients during acute complication compared to steady state, although the difference between steady state and acute complication was variable from one patient to another. (4) Conclusions: The present study demonstrates that oxygen gradient ektacytometry parameters are affected by sickle cell disease (SCD) genotype and treatment.

scholarly journals Is there a role for selective vasodilation in the management of sickle cell disease?

Blood ◽  
1988 ◽  
Vol 71 (3) ◽  
pp. 597-602 ◽  
Author(s):  
GP Rodgers ◽  
MS Roy ◽  
CT Noguchi ◽  
AN Schechter
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
Microvascular Obstruction ◽  
Controlled Study ◽  
Control Group ◽  
Cell Disease ◽  
Retinal Arteriolar

Abstract To test the hypothesis that microvascular obstruction to blood flow at the level of the arteriole may be significant in individuals with sickle cell anemia, the ophthalmologic effects of orally administered nifedipine were monitored in 11 steady-state patients. Three patients with evidence of acute peripheral retinal arteriolar occlusion displayed a prompt reperfusion of the involved segment. Two other patients showed fading of retroequatorial red retinal lesions. Color vision performance was improved in six of the nine patients tested. The majority of patients also demonstrated a significant decrease in the amount of blanching of the conjunctiva which reflects improved blood flow to this frequently involved area. Such improvements were not observable in a control group of untreated stable sickle cell subjects. These findings support the hypothesis that inappropriate vasoconstriction or frank vasospasm may be a significant factor in the pathogenesis of the microvascular lesions of sickle cell disease and, further, that selective microvascular entrapment inhibition may offer an additional strategy to the management of this disorder. We believe a larger, placebo-controlled study with nifedipine and similar agents is warranted.

Acute phase proteins and interleukins in steady state sickle cell disease

2009 ◽  
Vol 61 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Konstantinos L. Bourantas ◽  
Georgios N. Dalekos ◽  
Alexandres Makis ◽  
Aristidis Chaidos ◽  
Stavroula Tsiara ◽  
...  
Keyword(s):  
Steady State ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Acute Phase ◽  
Acute Phase Proteins ◽  
Cell Disease

scholarly journals Normal Non-HDL Cholesterol, Low Total Cholesterol, and HDL Cholesterol Levels in Sickle Cell Disease Patients in the Steady State: A Case-Control Study of Tema Metropolis

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Richard K. D. Ephraim ◽  
Patrick Adu ◽  
Edem Ake ◽  
Hope Agbodzakey ◽  
Prince Adoba ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Steady State ◽  
Sickle Cell Disease ◽  
Total Cholesterol ◽  
Sickle Cell ◽  
Density Lipoprotein ◽  
Hdl Cholesterol ◽  
Lipoprotein Cholesterol ◽  
Cell Disease ◽  
Cross Sectional

Background.Abnormal lipid homeostasis in sickle cell disease (SCD) is characterized by defects in plasma and erythrocyte lipids and may increase the risk of cardiovascular disease. This study assessed the lipid profile and non-HDL cholesterol level of SCD patients.Methods.A hospital-based cross-sectional study was conducted in 50 SCD patients, in the steady state, aged 8–28 years, attending the SCD clinic, and 50 healthy volunteers between the ages of 8–38 years. Serum lipids were determined by enzymatic methods and non-HDL cholesterol calculated by this formula: non-HDL-C = TC-HDL-C.Results.Total cholesterol (TC) (p=0.001) and high-density lipoprotein cholesterol (HDL-C) (p<0.0001) were significantly decreased in cases compared to controls. The levels of non-HDL-C, low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were similar among the participants. The levels of decrease in TC and HDL were associated with whether a patient was SCD-SS or SCD-SC. Systolic blood pressure and diastolic blood pressure were each significantly associated with increased VLDL [SBP,p=0.01, OR: 0.74 (CI: 0.6–0.93); DBP,p=0.023, OR: 1.45 (CI: 1.05–2.0)].Conclusion.Dyslipidemia is common among participants in this study. It was more pronounced in the SCD-SS than in SCD-SC. This dyslipidemia was associated with high VLDL as well as increased SBP and DBP.

scholarly journals Hematological and Biochemical Reference Ranges for the Population with Sickle Cell Disease at Steady State in Tanzania

Hemato ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 82-97
Author(s):  
Anna Daniel Fome ◽  
Raphael Z. Sangeda ◽  
Emmanuel Balandya ◽  
Josephine Mgaya ◽  
Deogratius Soka ◽  
...  
Keyword(s):  
Steady State ◽  
Sickle Cell Disease ◽  
General Population ◽  
Sickle Cell ◽  
Age Groups ◽  
Mean Corpuscular Hemoglobin ◽  
Reference Ranges ◽  
Cell Disease ◽  
Laboratory Reference ◽  
Males And Females

Hematological and biochemical reference values in sickle cell disease (SCD) are crucial for patient management and the evaluation of interventions. This study was conducted at Muhimbili National Hospital (MNH) in Dar es Salaam, Tanzania, to establish laboratory reference ranges among children and adults with SCD at steady state. Patients were grouped into five age groups and according to their sex. Aggregate functions were used to handle repeated measurements within the individual level in each age group. A nonparametric approach was used to smooth the curves, and a parametric approach was used to determine SCD normal ranges. Comparison between males and females and against the general population was documented. Data from 4422 patients collected from 2004–2015 were analyzed. The majority of the patients (35.41%) were children aged between 5–11 years. There were no significant differences (p ≥ 0.05) in mean corpuscular hemoglobin concentration (MCHC), lymphocytes, basophils, and direct bilirubin observed between males and females. Significant differences (p < 0.05) were observed in all selected parameters across age groups except with neutrophils and MCHC in adults, as well as platelets and alkaline phosphatase in infants when the SCD estimates were compared to the general population. The laboratory reference ranges in SCD at steady state were different from those of the general population and varied with sex and age. The established reference ranges for SCD at steady state will be helpful in the management and monitoring of the progress of SCD.

scholarly journals Decreased Hepcidin Levels Are Associated with Low Steady-state Hemoglobin in Children With Sickle Cell Disease in Tanzania

EBioMedicine ◽  
2018 ◽  
Vol 34 ◽  
pp. 158-164 ◽  
Author(s):  
Nathaniel Lee ◽  
Julie Makani ◽  
Furahini Tluway ◽  
Abel Makubi ◽  
Andrew E. Armitage ◽  
...  
Keyword(s):  
Steady State ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Cell Disease
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