Whole Blood Tissue Factor Procoagulant Activity Is Elevated in Patients With Sickle Cell Disease

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4216-4223 ◽  
Author(s):  
Nigel S. Key ◽  
Arne Slungaard ◽  
Luke Dandelet ◽  
Stephen C. Nelson ◽  
Christopher Moertel ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Tissue Factor ◽  
Mononuclear Cell ◽  
Sickle Cell ◽  
Whole Blood ◽  
Procoagulant Activity ◽  
Cell Disease ◽  
Blood Samples ◽  
Significant Difference ◽  
Whole Blood Samples

Abstract We developed a simple assay for the measurement of tissue factor procoagulant activity (TF PCA) in whole blood samples that avoids the need for mononuclear cell isolation. This method combines convenience of sample collection and processing with a high degree of sensitivity and specificity for TF. Using this method, we have determined that TF PCA is detectable in whole blood samples from normal individuals, which is itself a novel observation. Essentially all PCA could be shown to be localized in the mononuclear cell fraction of blood. Compared with controls, whole blood TF levels were significantly (P < .000001) elevated in patients with sickle cell disease (SCD), regardless of the subtype of hemoglobinopathy (SS or SC disease). No significant difference in TF PCA was observed between patients in pain crisis compared with those in steady-state disease. Because TF functions as cofactor in the proteolytic conversion of FVII to FVIIa in vitro, it was expected that an increase in circulating TF PCA would lead to an increased in vivo generation of FVIIa. On the contrary, FVIIa levels were actually decreased in the plasma of patients with SCD. Plasma TF pathway inhibitor (TFPI) antigen levels were normal in SCD patients, suggesting that accelerated clearance of FVIIa by the TFPI pathway was not responsible for the reduced FVIIa levels. We propose that elevated levels of circulating TF PCA may play an important role in triggering the activation of coagulation known to occur in patients with SCD. Because TF is the principal cellular ligand for FVIIa, it is possible that increased binding to TF accounts for the diminished plasma FVIIa levels.

Whole Blood Tissue Factor Procoagulant Activity Is Elevated in Patients With Sickle Cell Disease

Blood ◽  
1998 ◽  
Vol 91 (11) ◽  
pp. 4216-4223 ◽  
Author(s):  
Nigel S. Key ◽  
Arne Slungaard ◽  
Luke Dandelet ◽  
Stephen C. Nelson ◽  
Christopher Moertel ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Tissue Factor ◽  
Mononuclear Cell ◽  
Sickle Cell ◽  
Whole Blood ◽  
Procoagulant Activity ◽  
Cell Disease ◽  
Blood Samples ◽  
Significant Difference ◽  
Whole Blood Samples

We developed a simple assay for the measurement of tissue factor procoagulant activity (TF PCA) in whole blood samples that avoids the need for mononuclear cell isolation. This method combines convenience of sample collection and processing with a high degree of sensitivity and specificity for TF. Using this method, we have determined that TF PCA is detectable in whole blood samples from normal individuals, which is itself a novel observation. Essentially all PCA could be shown to be localized in the mononuclear cell fraction of blood. Compared with controls, whole blood TF levels were significantly (P < .000001) elevated in patients with sickle cell disease (SCD), regardless of the subtype of hemoglobinopathy (SS or SC disease). No significant difference in TF PCA was observed between patients in pain crisis compared with those in steady-state disease. Because TF functions as cofactor in the proteolytic conversion of FVII to FVIIa in vitro, it was expected that an increase in circulating TF PCA would lead to an increased in vivo generation of FVIIa. On the contrary, FVIIa levels were actually decreased in the plasma of patients with SCD. Plasma TF pathway inhibitor (TFPI) antigen levels were normal in SCD patients, suggesting that accelerated clearance of FVIIa by the TFPI pathway was not responsible for the reduced FVIIa levels. We propose that elevated levels of circulating TF PCA may play an important role in triggering the activation of coagulation known to occur in patients with SCD. Because TF is the principal cellular ligand for FVIIa, it is possible that increased binding to TF accounts for the diminished plasma FVIIa levels.

A Novel Connection Between Stress Erythropoiesis and Coagulation Activation in Sickle Cell Disease.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 905-905
Author(s):  
Julia E. Brittain ◽  
David Manly ◽  
Leslie V. Parise ◽  
Nigel Mackman ◽  
Kenneth I. Ataga
Keyword(s):  
Flow Cytometry ◽  
Sickle Cell Disease ◽  
Tissue Factor ◽  
Sickle Cell ◽  
Whole Blood ◽  
Conflicts Of Interest ◽  
Cell Disease ◽  
Coagulation Activation ◽  
Monocytic Cells ◽  
Stress Erythropoiesis

Abstract Abstract 905 Introduction: Sickle cell disease (SCD) is associated with a hypercoagulable state. Multiple studies show that plasma from these patients exhibit: 1) increased thrombin generation; 2) decreased levels of natural anticoagulant proteins; and 3) a defect in the activation of fibrinolysis. The mechanism of coagulation activation in SCD is presumed to be multi-factorial, with contributions from abnormal erythrocyte phospholipid asymmetry and induction of tissue factor (TF) following hemolysis. In addition, hemolysis in SCD leads to elevated levels of erythropoietin (EPO) in patients, increased reticulocyte counts and the presence of stress (or shift) reticulocytes in circulating blood. These stress reticulocytes retain expression of the α4b1 integrin and are demonstrably adhesive to vascular factors in SCD. We have previously reported that these stress reticulocytes bind to blood monocytes in SCD patients via the α4b1 integrin, but the effect of this interaction on either cell remained unknown in SCD. Objective: With the increasing evidence that hemolysis and subsequent stress erythropoiesis associates with coagulation activation, we sought to evaluate the role of erythropoietin and the effect of stress reticulocyte adhesion to monocytes on coagulation activation in SCD patients. Methods: Coagulation activation in plasma samples was examined by evaluating TF activity on microparticles derived from patients with SCD. Stress reticulocytes were visualized and enumerated from these same patients using Wright Giemsa stained blood smears counter stained with new methylene blue to detect reticulocytes. Reticulocytes were scored as a stress reticulocytes based on the amount of punctuate reticular material, cell size, and presence of nuclear material. Stress reticulocyte induction of monocyte tissue factor expression was measured by flow cytometry after incubation of THP-1 monocytic cells with purified SS RBCs or control RBCs. To determine if induced THP-1 TF expression was due stress reticulocyte binding, THP-1 TF expression was examined in the presence or absence of known inhibitors of the monocyte/stress reticulocyte interaction. TF expression on CD14+ monocytes was examined in whole blood from SCD patients using flow cytometry. Plasma erythropoietin levels were quantified by ELISA. Results: We found that direct binding of the stress reticulocyte increased THP-1 TF expression 2.5 fold. This increase in TF expression was completely ablated by function blocking antibodies against the α4 integrin, but not by an isotype-matched control IgG. In whole blood samples, we also found increased TF expression on CD14+ monocytes with stress reticulocytes directly bound, compared to those monocytes in the same patient without stress reticulocytes bound (p = 0.002, n =3).We noted a strong correlation between stress reticulocyte count and TF activity on plasma microparticles in SCD (rspearman = 0.8656, CI = 0.5382 – 0.9660, p = 0.0006, n=11). Furthermore, we found that EPO induced α4b1 activation on the stress reticulocyte. This activation may promote both adhesion to the monocyte and an increase in TF expression. Consequently, we noted a strong trend towards an association of EPO with microparticle TF activity in SCD (rspearman = 0.5740, CI=-0.06 – 0.8780, p=0.068, n= 11) suggesting that EPO, by promoting the interaction between the stress reticulocyte and the monocyte, may contribute to TF activity in SCD. Conclusion: Taken together, we find that stress reticulocyte adhesion to monocytes and monocytic cells induces TF expression and may promote TF activity in patients. These data suggest a novel connection between stress erythropoiesis and coagulation activation in SCD. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Visualizing Sickle Cell Disease Whole Blood Flow and Viscosity through Modifications to Hemoglobin Levels from a Simple Blood Transfusion

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3244-3244
Author(s):  
Kirby S. Fibben ◽  
Wilbur A. Lam ◽  
Dan Y. Zhang ◽  
Melissa L. Kemp ◽  
David K. Wood ◽  
...  
Keyword(s):  
Blood Flow ◽  
Sickle Cell Disease ◽  
Velocity Profile ◽  
Sickle Cell ◽  
Whole Blood ◽  
Red Cells ◽  
Patient Specific ◽  
Red Cell ◽  
Cell Disease ◽  
Blood Samples

Abstract Red cell transfusions are an effective part of a clinical care regiment in the treatment of chronic sickle cell disease; however, the understanding of the target hemoglobin levels has not been investigated past the standard hematocrit/hemoglobin (HgB) of 10 g/dL. A simple transfusion of packed red cells can be a beneficial clinical treatment of acute pain crisis or even stroke. Along with other transfusion-based complications, when performing a simple transfusion, the changes in blood velocity as a result of increased blood viscosity from the additional red cells can lead to complications of their own. Because of this, clinical treatment has hesitated to transfuse sickle patients above a HgB of 10 g/dL. The complications of sickle cell disease tend to be more pronounced on the microvascular scale than then macrovascular. Along with this, the overall slower blood flow caused by the increase in viscosity from a simple blood transfusion is more probable to lead to complications on the microvascular level. Our device allows us to target the changes in whole blood on multiple scales including down to arteriole sizes. Here, we have begun to investigate how transfusion could be more patient-specific by identifying the velocity profile of whole blood flowing through a "microvasculature-on-a-chip" device that mimics the microvascular geometry (Figure 1A). The devices were microfabricated using polydimethylsiloxane (PDMS) and then coated with 0.1% bovine serum albumin (BSA) to help prevent red cell adhesion to channel walls. To simulate various HgB levels, healthy whole blood samples were centrifuged to separate red cells. To simulate a simple clinical transfusion of a sickle patient, isolated red cells were added to sickle whole blood samples. Similar to a clinical setting, sickle samples were only transfused up to higher HgB levels. HgB levels were then confirmed on a differential hematology analyzer (Sysmex XN 330). 3.2mm CA+ was added to various HgB samples to defeat the citrate anticoagulant. Samples were loaded into syringes then perfused into the BSA coated devices (Figure 1B). During perfusion, a 450 frame video of flow was captured at 40x resolution and 163 fps. Following capture, videos parameters such as frame rate and pixel distance were defined in a custom MATLAB (Mathworks, Natick, MA) script. The script segmented videos into cropped frames of the desired regions of interest then a Kanade-Lucas-Tomasi (KLT) tracking algorithm detected red cell features in each frame across 4 frames (Figure 1 B&C). 12 equal spaced bins were created across the width of the channel in the direction of flow; Tracked velocities were assigned to their corresponding bin and averaged to create a velocity profile of function as the distance from the center of the channel (Figure 1 D&E). To create a case study, two patient samples were received with the same starting HgB of 6.8 g/dL and were transfused upwards incrementally to a HgB of 12 g/dL. One patient is currently on a hydroxyurea regiment and the other patient is not. At each HgB level, the perfused whole blood was tracked through several different arteriole-sized vessels (30, 40 & 60 um) at two appropriate flow rates. To quantify the differences in the flow, the average cell velocity (um/s) through the channel and the peak velocity (um/s) through channels were charted against the various HgB levels (Figure 2). Continuing this series of experiments, 2 additional sickle whole blood on hydroxyurea samples were transfused upwards from their respective starting hemoglobin (9.7 & 10 g/dL). The flow was tracked and averages were quantified across the channel through its distance from the center of the channel. As transfused sickle HgB levels were increased, the bluntness of the velocity profile, or the difference between the average flow velocity in the center of the channel and at the walls of the channel, became less dramatic. This could be primarily attributed to the increase in the viscosity from the addition of the red cells (Figure 3). Our data shows that viscosity plays an important factor in whole blood flow. HgB of 10 g/dL is an important target for sickle transfusions; however, this target HgB may be more patient-specific than previously stated. Understanding patient viscosity may prove to be more important than hemoglobin levels. As patient blood increases in viscosity, blood slows down on the microvascular level the most. This may be critical in understanding the appropriate transfusion. Figure 1 Figure 1. Disclosures Lam: Sanguina, Inc.: Current holder of individual stocks in a privately-held company. Kemp: Parthenon Therapeutics: Membership on an entity's Board of Directors or advisory committees.

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 Tissue factor promotes activation of coagulation and inflammation in a mouse model of sickle cell disease

Blood ◽  
2012 ◽  
Vol 120 (3) ◽  
pp. 636-646 ◽  
Author(s):  
Pichika Chantrathammachart ◽  
Nigel Mackman ◽  
Erica Sparkenbaugh ◽  
Jian-Guo Wang ◽  
Leslie V. Parise ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Sickle Cell Disease ◽  
Tissue Factor ◽  
Sickle Cell ◽  
Plasma Levels ◽  
Cell Injury ◽  
Vascular Inflammation ◽  
Cell Disease ◽  
Endothelial Cell Injury ◽  
Cell Adhesion Molecule 1

Abstract Sickle cell disease (SCD) is associated with a complex vascular pathophysiology that includes activation of coagulation and inflammation. However, the crosstalk between these 2 systems in SCD has not been investigated. Here, we examined the role of tissue factor (TF) in the activation of coagulation and inflammation in 2 different mouse models of SCD (BERK and Townes). Leukocytes isolated from BERK mice expressed TF protein and had increased TF activity compared with control mice. We found that an inhibitory anti-TF antibody abrogated the activation of coagulation but had no effect on hemolysis or anemia. Importantly, inhibition of TF also attenuated inflammation and endothelial cell injury as demonstrated by reduced plasma levels of IL-6, serum amyloid P, and soluble vascular cell adhesion molecule-1. In addition, we found decreased levels of the chemokines MCP-1 and KC, as well as myeloperoxidase in the lungs of sickle cell mice treated with the anti-TF antibody. Finally, we found that endothelial cell-specific deletion of TF had no effect on coagulation but selectively attenuated plasma levels of IL-6. Our data indicate that different cellular sources of TF contribute to activation of coagulation, vascular inflammation, and endothelial cell injury. Furthermore, it appears that TF contributes to these processes without affecting intravascular hemolysis.

scholarly journals Identifying Potential Drug Targets for Sickle Cell Disease through Gene Expression and Pathway Analysis of GEO Data

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 15-16
Author(s):  
Sharjeel Syed ◽  
Jihad Aljabban ◽  
Jonathan Trujillo ◽  
Saad Syed ◽  
Robert Cameron ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Drug Targets ◽  
Meta Analysis ◽  
Cell Disease ◽  
Blood Samples ◽  
Disease Modifying Therapies ◽  
Disease Modifying

Background: The pathogenesis of sickle cell disease (SCD) and its complications have been well characterized down to the molecular level. However, there remains a relative dearth of disease modifying therapies that reduce the frequency and number of vas-occlusive crises, hospitalizations, and deaths. Recent advancements in utilizing hydroxyurea and L-glutamine, which both impact unique disease pathways, should pave way for the identification of other molecular pathways as ideal drug targets. In this regard, our meta-analysis serves to identify key genes and associated pathways that are differentially expressed in SC patients. Methods: We employed our STARGEO platform to tag samples from the NCBI Gene Expression Omnibus and performed meta-analysis to compare SC and healthy control transcriptomes. For the meta-analysis, we tagged 285 peripheral blood samples from SC patients and 86 samples from healthy subjects as a control. We then analyzed the signature in Ingenuity Pathway Analysis to elucidate top disease functions from our analysis. Results: From our meta-analysis, we identified iron homeostasis signaling, NRF2-mediated oxidative stress response, cell senescence, and pyrimidine interconversion/biosynthesis as top canonical pathways that were upregulated in the peripheral blood samples from SC patients. Top upstream regulators included membrane associated protein and transporter ABCB6, non-coding RNY3, and erythroid maturation transcription factors GATA1, KLF1, and HIPK2 (with predicted activation). The most upregulated genes included inflammatory modulators RNF182 and IFI27, the latter of which has been shown to inhibit vascular endothelial growth and repair. Several membrane-associated protein coding genes such as GYPA, RAP1GAP, and PAQR9 were also upregulated in the SC samples. RAP1GAP is known to modulate neutrophil cell adhesion and homing while PAQR9 has roles in regulating protein quality control: a role also seen in similarly upregulated YOD1, a deubiquitinating enzyme involved in trafficking of misfolded proteins. Expectedly, also upregulated were HBBP1 and SOX6, which regulate globin genes and have been shown to silence γ-globin expression. Lastly, SLC6A19, the neutral amino acid transporter mutated in Hartnup disease, was also upregulated. Of the downregulated genes, WASF3, a member of the Wiskott-Aldrich syndrome protein family, has been linked to poor survival in many malignancies, including AML and CMML, but has not previously been linked to SCD pathogenesis. ENKUR was also downregulated and has been annotated as a tethering protein to cation channels as well as linked to pathways involving vascular leakage. SIGLEC10, which binds to vascular adhesion proteins, is a key suppressor of inflammatory responses to damage; it's downregulation along with ELAPOR1, a transmembrane protein involved in cellular response to stress, was also observed. Finally, based off the focus genes in our analysis we identified several networks with most being involved in amino acid metabolism, cellular assembly, function, and maintenance, hematological disease, and organismal injury. The top pathway is illustrated in Figure 1. Conclusions: Our study illustrates differentially expressed gene activity in SCD consistent with known pathophysiology such as immune response, endothelial damage and adherence, heme metabolism, and globin regulation. We also showed evidence of genes not previously studied in SCD, which may have novel roles such as those part of the ubiquitin-proteasome system like YOD1 and RNF182. Additionally, while some genes in our analysis like EKLF and GAT1 have been shown to enhance δ-globin expression, paving way for possible drug therapies for B-hemoglobinopathies, others like IFI27, PAQR9, RAP1GAP, ENKUR, SIGLEC10, WASF3, and SOX9 have yet to be studied as mediators of disease pathogenesis in SCD. A target to SOX9, a known suppressor of γ-globin, or ABCB6, a known modulator of erythroid cell shape and hydration, have particularly promising potential as disease modifying therapies. Finally, HIPK2, HBBP1, and SLC6A19 have previously been shown to have intriguing effects on hydroxyurea dosing and responsivity in SC patients and may also be candidate target molecules to enhance existing therapies. These data identify potential candidate pathways for mechanistic studies seeking to confirm a causative role in the pathogenesis of sickle cell disease. Disclosures No relevant conflicts of interest to declare.

scholarly journals Pregnancies and Neonatal Outcomes in Patients with Sickle Cell Disease (SCD): Still a (High-)Risk Constellation?

2021 ◽  
Vol 11 (9) ◽  
pp. 870
Author(s):  
Pia Proske ◽  
Laura Distelmaier ◽  
Carmen Aramayo-Singelmann ◽  
Nikolaos Koliastas ◽  
Antonella Iannaccone ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Neonatal Outcomes ◽  
University Hospital ◽  
High Rate ◽  
Successful Outcome ◽  
Acute Chest Syndrome ◽  
Cell Disease ◽  
Significant Difference ◽  
Tract Infections

Background: This monocentric study conducted at the University Hospital of Essen aims to describe maternal and fetal/neonatal outcomes in sickle cell disease (SCD) documented between 1996 to 2021 (N = 53), reflecting the largest monocentric analysis carried out in Germany. Methods/Results: 46 pregnancies in 22 patients were followed. None of the patients died. In total, 35% (11/31) of pregnancies were preterm. 15 pregnancies in eight patients were conceived on hydroxycarbamide (HC), of which nine had a successful outcome and three were terminated prematurely. There was no difference regarding the rate of spontaneous abortions in patients receiving HC compared to HC-naive patients prior to conception. In patients other than HbS/C disease, pregnancies were complicated by vaso-occlusive crises (VOCs)/acute pain crises (APCs) (96%, 23/24); acute chest syndrome (ACS) (13%, 3/24), transfusion demand (79%, 19/24), urinary tract infections (UTIs) (42%, 10/24) and thromboembolic events (8%, 2/24). In HbS/C patients complications included: VOCs/APCs (43%, 3/7; ACS: 14%, 1/7), transfusion demand (14%, 1/7), and UTIs (14%, 1/7). Independent of preterm deliveries, a significant difference with respect to neonatal growth in favor of neonates from HbS/C mothers was observed. Conclusion: Our data support the results of previous studies, highlighting the high rate of maternal and fetal/neonatal complications in pregnant SCD patients.

scholarly journals Whole Blood Adhesion to VCAM-1 and P-Selectin and RBC Mechanical Fragility Can be Compromised in Long COVID-19 Patients with Sickle Cell Disease

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 959-959
Author(s):  
Michael Tarasev ◽  
Marta Ferranti ◽  
Cidney Allen ◽  
Xiufeng Gao ◽  
Kayla Topping ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Blood Cell ◽  
Sickle Cell ◽  
Whole Blood ◽  
Stock Options ◽  
Membrane Stability ◽  
Cell Disease ◽  
Adhesive Properties ◽  
Rbc Membrane ◽  
Privately Held

Abstract Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause severe vascular complications associated with endothelial dysfunction and systemic inflammation. COVID19-specific IgG are detectable within a week of infection. Long COVID-19 has been described in patients continuing to exhibit symptoms after the virus is no longer detectable in the respiratory secretions, including fatigue, dyspnea, headache, and brain fog. The recent FAIR Health study reviewed a total of 1,959,982 COVID-19 patients for the prevalence of long COVID symptoms and reported that 23.2% had at least one post-COVID symptom [1]. The underlying biologic mechanisms of long COVID remain unclear, thus treatments are limited to symptomatic relief and supportive care. Many long COVID symptoms are consistent with systemic inflammation and impaired oxygen delivery observed in individuals with sickle cell disease (SCD), in turn associated with elevated blood cell adhesion and decreased red blood cell (RBC) stability. The aim of this study was to determine if deleterious changes in in blood cell properties related to adhesion and membrane stability under stress can be associated with the symptoms of long COVID-19. In this work we evaluated 7 SCD patients that were diagnosed with SARS-Cov-2 and tracked their recovery using semiquantitative IgG and blood cell function assays. Methods: Blood samples were collected by the Foundation for Sickle Cell Disease (SCD) Research from SCD (homozygous SS, n=6) patients coming for regular or urgent clinic visit with SARS-CoV-2 serological and blood cell functions tests performed per the standard of care. Semiquantitative IgG assay was performed using DXi-80 (Beckman Coulter). Flow adhesion of whole blood to VCAM-1 (FA-WB-VCAM)and P-Selectin (FA-WB-Psel) substrates were determined by counting the cells that remain adherent in a microfluidics channel after perfusion with whole blood 1:1 diluted with HBSS buffer and washed by reversed flow at 1 dyne/cm 2. Red blood cell mechanical fragility (RBC MF) was measured as hemolysis induced by an oscillating cylindrical magnet with periodic non-invasive probing of cell-free hemoglobin fraction. Six individuals with SCD recovering from SARS-Cov-2 with biomarker data available both before and for more than 3 months after the infection (179±62 days) were included in the study. Results: IgG levels varied from less than 0.1 to 37, with positive values being defined as IgG &gt; 1. The median estimated half-life of IgG decline was 53 days ranging from 25 to 90 days (the last, for the hospitalized patient). Averaged for IgG positive (IgG+) and IgG negative (IgG-) conditions, combining pre- and post-infection IgG- conditions, values of patient hemoglobin (Hb), FA-WB-VCAM, FA-WB-Psel, and RBC MF cell properties lacked statistical significance (under both a paired t-test and population statistics). Hb levels remained essentially unchanged regardless of the time from infection or IgG status. However, FA-WB-VCAM, FA-WB-Psel, and RBC MF were all significantly elevated after SARS-Cov-2 seroconversion and remained elevated despite declining IgG levels (e.g., Fig. 1). These increases in biomarker values were statistically significant for both FA-WB-VCAM and RBC MF, and were approaching significance for FA-WB-Psel (p&lt;0065). These increases were highly patient-specific with potential return to pe-infection values observed in some cases at about 5-6 months after the infection. A qualitative review of the medical records indicated a new subjective report of fatigue in 5 of 6 patients. Longer observations are required to determine if abnormal blood cell adhesive properties and RBC membrane instability are mechanisms of long-COVID-19 pathophysiology. Conclusions: Whole blood adhesion to both p-selectin and VCAM-1 as well as RBC membrane stability can be significantly impaired in convalescent SARS-Cov-2 patients suggesting an association with long COVID-19. New and emerging treatments that modify whole blood adhesive properties and RBC membrane stability should be investigated for their potential to accelerated recovery from long COVID-19. Health F. A Detailed Study of Patients with Long-Haul COVID: An Analysis of Private Healthcare Claims; White Paper. June 15, 2021 Disclosures Tarasev: Functional Fluidics: Current holder of stock options in a privately-held company. Ferranti: Functional Fluidics: Current holder of stock options in a privately-held company. Allen: Functional Fluidics: Current Employment. Gao: Functional Fluidics: Current Employment. Topping: Functional Fluidics: Current Employment. Ferranti: Functional Fluidics: Current Employment. Makinde-Odesola: Functional Fluidics: Other: conduct research for academic program. Hines: Functional Fluidics: Current holder of stock options in a privately-held company.

scholarly journals Featured Article: Depletion of HDL3 high density lipoprotein and altered functionality of HDL2 in blood from sickle cell patients

2017 ◽  
Vol 242 (12) ◽  
pp. 1244-1253 ◽  
Author(s):  
Eric Soupene ◽  
Sandra K Larkin ◽  
Frans A Kuypers
Keyword(s):  
Sickle Cell Disease ◽  
High Density Lipoprotein ◽  
Sickle Cell ◽  
Acute Phase ◽  
Whole Blood ◽  
Density Lipoprotein ◽  
High Density ◽  
High Density Lipoproteins ◽  
Mrna Levels ◽  
Cell Disease

In sickle cell disease (SCD), alterations of cholesterol metabolism is in part related to abnormal levels and activity of plasma proteins such as lecithin cholesterol acyltransferase (LCAT), and apolipoprotein A-I (ApoA-I). In addition, the size distribution of ApoA-I high density lipoproteins (HDL) differs from normal blood. The ratio of the amount of HDL2 particle relative to the smaller higher density pre-β HDL (HDL3) particle was shifted toward HDL2. This lipoprotein imbalance is exacerbated during acute vaso-occlusive episodes (VOE) as the relative levels of HDL3 decrease. HDL3 deficiency in SCD plasma was found to relate to a slower ApoA-I exchange rate, which suggests an impaired ABCA1-mediated cholesterol efflux in SCD. HDL2 isolated from SCD plasma displayed an antioxidant capacity normally associated with HDL3, providing evidence for a change in function of HDL2 in SCD as compared to HDL2 in normal plasma. Although SCD plasma is depleted in HDL3, this altered capacity of HDL2 could account for the lack of difference in pro-inflammatory HDL levels in SCD as compared to normal. Exposure of human umbilical vein endothelial cells to HDL2 isolated from SCD plasma resulted in higher mRNA levels of the acute phase protein long pentraxin 3 (PTX3) as compared to incubation with HDL2 from control plasma. Addition of the heme-scavenger hemopexin protein prevented increased expression of PTX3 in sickle HDL2-treated cells. These findings suggest that ApoA-I lipoprotein composition and functions are altered in SCD plasma, and that whole blood transfusion may be considered as a blood replacement therapy in SCD. Impact statement Our study adds to the growing evidence that the dysfunctional red blood cell (RBC) in sickle cell disease (SCD) affects the plasma environment, which contributes significantly in the vasculopathy that defines the disease. Remodeling of anti-inflammatory high density lipoprotein (HDL) to pro-inflammatory entities can occur during the acute phase response. SCD plasma is depleted of the pre-β particle (HDL3), which is essential for stimulation of reverse cholesterol from macrophages, and the function of the larger HDL2 particle is altered. These dysfunctions are exacerbated during vaso-occlusive episodes. Interaction of lipoproteins with endothelium increases formation of inflammatory mediators, a process counteracted by the heme-scavenger hemopexin. This links hemolysis to lipoprotein-mediated inflammation in SCD, and hemopexin treatment could be considered. The use of RBC concentrates in transfusion therapy of SCD patients underestimates the importance of the dysfunctional plasma compartment, and transfusion of whole blood or plasma may be warranted.

scholarly journals Whole blood as an alternative to peripheral blood mononuclear cell for detection of total HIV-1 DNA

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ling Lin ◽  
Yong-Song Yue ◽  
Ni-Dan Wang ◽  
Lei-Yan Wei ◽  
Yang Han ◽  
...  
Keyword(s):  
Peripheral Blood Mononuclear Cell ◽  
Mononuclear Cell ◽  
Whole Blood ◽  
Peripheral Blood ◽  
Antiviral Treatment ◽  
Quantitative Detection ◽  
Peripheral Blood Mononuclear ◽  
Blood Samples ◽  
Whole Blood Samples ◽  
Hiv 1

Abstract Background A more time saving, convenient, reproducible, and scalable method is needed to assess total HIV-1 DNA levels. Methods Frozen whole blood and peripheral blood mononuclear cell (PBMC) samples both 200 μl at the same point were used to detect total HIV-1 DNA. Automatic extraction of total HIV-1 DNA was used to ensure the consistency of sample extraction efficiency. The detection reagent was HIV-1 DNA quantitative detection kit and real-time quantitative PCR was utilized. Results Of the 44 included patients, 42 were male and 2 were female, with a median age of 33 years. Thirty-three cases were collected after receiving antiviral treatment, with a median duration of treatment of 3 months, and the other 11 cases were collected before antiviral treatment. The median viral load was 1.83 log10 copies/mL, the median CD4 and CD8 count were 94 and 680 cells/μL, and the median CD4/CD8 ratio was 0.18. The results of the two samples were 3.02 ± 0.39 log10 copies/106 PBMCs in PBMC samples and 3.05 ± 0.40 log10 copies/106 PBMCs in whole blood samples. The detection results of the two methods were highly correlated and consistent by using paired t test (P = 0.370), pearson correlation (r = 0.887, P < 0.0001) and intra-group correlation coefficient (ICC = 0.887, P < 0.0001) and bland-altman [4.55% points were outside the 95% limits of agreement (− 0.340 ~ 0.390)]. Conclusions The results of the whole blood sample test for total HIV-1 DNA are consistent with those of PBMC samples. In a clinical setting it is recommended to use whole blood samples directly for the evaluation of the HIV reservoir.

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