Type-2 Phosphatidylserine (PS)-Positive Erythrocytes and Their Association with Markers of Hemolysis and Hemostatic Activation in Children with Sickle Cell Disease (SCD)

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 943-943
Author(s):  
Yamaja B. Setty ◽  
Suhita Gayennebetal ◽  
Nigel S. Key ◽  
Marie Stuart
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Red Cells ◽  
Red Cell ◽  
Cell Disease ◽  
Activation Markers ◽  
D Dimer

Abstract Introduction: Type-2 phosphatidylserine (PS)-positive red cells are a subpopulation of erythrocytes that are highly positive for PS, contain low levels of fetal hemoglobin, are specific for sickle cell disease (SCD) and have been identified in the dense red cell fraction. Studies have implicated PS-positive red cells in enhancing anemia due to phagocytosis and hemolysis. Shielding of red cell PS by diannexin, a synthetic homodimer of human annexin-V, has been demonstrated to provide protection against hemolysis and prevent activation of prothrombinase. Methods: Using flow cytometry, we measured the levels of type-1 (red cells with low PS positivity) and type-2 PS-positive red cells in 50 children with SCD (31 with HbSS and 19 with HbSC), and assessed their association with various markers of hemolysis and hemostatic activation. Markers of hemolysis evaluated included plasma lactate dehydrogenase (LDH), reticulocyte count, and hemoglobin. Whole blood tissue factor (WBTF), pro-thrombin fragment F1+2, and D-dimer were evaluated as markers of hemostatic activation. Results: We demonstrate that the levels of type-2 PS-positive red cells are significantly increased in HbSS patients (1.37 ± 0.97%, p<0.01) compared to children with HbSC disease (0.32 ± 0.21%) and age- and race-matched controls (0.15 ± 0.15%, n=19). WBTF and D-dimer showed significant associations with both type-1 and -2 red cells with no significant differences in the strength of their association. However, significantly greater correlations were noted between type-2 PS red cells and hemolytic markers compared to those noted with type-1 (Steiger's Z=3.05 to 4.59, p<0.01). In addition our in vitro studies demonstrate increased osmotic fragility of these red cells. Table 1. Association of PS-positive RBCs with markers of hemolysis and hemostatic activation Biomarker Type-1 PS-positive RBCs Type-2 PS-positive RBCs Markers of Hemolysis LDH r = 0.44, p<0.002 r = 0.63, p<0.00001 % Reticulocyte r = 0.43, p=0.002 r = 0.66, p<0.00001 Hemoglobin r =-0.35, p=0.014 r =-0.63, p<0.00001 Markers of Hemostatic Activation WBTF r = 0.41, p=0.008 r = 0.56, p<0.0002 F1+2 r = 0.26, p=0.07 r = 0.31, p<0.03 D-dimer r = 0.46, p<0.001 r = 0.56, p<0.0005 Conclusions: Type-2 PS-positive red cells are elevated in SCD and the number of these cells correlates significantly with both markers of hemolysis and hemostasis. These findings provide a patho-physiologic link between the intravascular hemolytic milieu of SCD and the hemostatic perturbations previously noted in this disease. Disclosures No relevant conflicts of interest to declare.

scholarly journals American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support

2020 ◽  
Vol 4 (2) ◽  
pp. 327-355 ◽  
Author(s):  
Stella T. Chou ◽  
Mouaz Alsawas ◽  
Ross M. Fasano ◽  
Joshua J. Field ◽  
Jeanne E. Hendrickson ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Iron Overload ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Guideline Development ◽  
Practice Research ◽  
Evidence Based ◽  
Red Cell ◽  
Cell Disease ◽  
American Society

Background: Red cell transfusions remain a mainstay of therapy for patients with sickle cell disease (SCD), but pose significant clinical challenges. Guidance for specific indications and administration of transfusion, as well as screening, prevention, and management of alloimmunization, delayed hemolytic transfusion reactions (DHTRs), and iron overload may improve outcomes. Objective: Our objective was to develop evidence-based guidelines to support patients, clinicians, and other healthcare professionals in their decisions about transfusion support for SCD and the management of transfusion-related complications. Methods: The American Society of Hematology formed a multidisciplinary panel that was balanced to minimize bias from conflicts of interest and that included a patient representative. The panel prioritized clinical questions and outcomes. The Mayo Clinic Evidence-Based Practice Research Program supported the guideline development process. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to form recommendations, which were subject to public comment. Results: The panel developed 10 recommendations focused on red cell antigen typing and matching, indications, and mode of administration (simple vs red cell exchange), as well as screening, prevention, and management of alloimmunization, DHTRs, and iron overload. Conclusions: The majority of panel recommendations were conditional due to the paucity of direct, high-certainty evidence for outcomes of interest. Research priorities were identified, including prospective studies to understand the role of serologic vs genotypic red cell matching, the mechanism of HTRs resulting from specific alloantigens to inform therapy, the role and timing of regular transfusions during pregnancy for women, and the optimal treatment of transfusional iron overload in SCD.

Protective Effect of Fetal Hemoglobin On Inflammation-Induced Expression of Hypoxia-Inducible Factor-1α (HIF-1α) in Sickle Mice: Microvascular Implications

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3250-3250
Author(s):  
Dhananjay K. Kaul ◽  
Mary E. Fabry ◽  
Sandra M Suzuka ◽  
Janki Shah
Keyword(s):  
Oxidative Stress ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Hypoxia Inducible Factor ◽  
Heme Oxygenase 1 ◽  
No Production ◽  
Cell Disease ◽  
Activation Markers ◽  
No Bioavailability

Abstract Abstract 3250 Chronic inflammation is a salient feature of human sickle cell disease (SCD) and transgenic-knockout sickle (BERK) mouse model. Although tissue ischemia is the primary instigator of hypoxia-inducible factor (HIF) activation, a number of inflammatory factors/pathways and oxidative stress can potentially induce expression of HIF-1α. Increased oxidative stress and inflammation are implicated in the activation of HIF-1α under normoxic conditions. HIF can trigger transcription of genes for vasoactive molecules such as vascular endothelial growth factor (VEGF), heme oxygenase-1 (HO-1) and endothelin, which are implicated in the pathophysiology of SCD. We hypothesize that, in SCD, inflammation coupled with nitric oxide (NO) depletion will induce expression of HIF-1α. To this end, we have examined the expression of HIF-1α in normoxic BERK mice expressing exclusively human α- and βS- globins, and evaluated the effect of HbF in BERK mice (i.e., <1.0%, 20% and 40% HbF). We have previously shown that HbF exerts anti-sickling and anti-inflammatory effects (Kaul et al. J Clin Invest, 2004; Dasgupta et al. Am J Physiol, 2010). Here, we show that HIF-1α is expressed in BERK mice under normoxic conditions (i.e., normal hemoglobin oxygen saturation levels). In BERK mice expressing HbF, HIF-1α expression decreased concomitantly with increasing HbF, commensurately with increased NO bioavailability, and showed a strong inverse correlation with plasma NO metabolites (NOx) levels. Reduced HIF-1α expression in BERK mice expressing HbF was associated with decreased HO-1 and VEGF expression, and reduced serum endothelin-1 (ET-1) levels, which are among the target vasoactive molecules of HIF-1α. Furthermore, the commensurate decrease in HIF-1α expression with increase in HbF levels in BERK mice was accompanied by a distinct decrease in soluble (s) forms of endothelial activation markers such as sP-selectin and vascular cell adhesion molecule-1 (sVCAM-1). Notably, arteriolar dilation, enhanced volumetric blood flow and low blood pressure in normoxic BERK mice all showed a trend toward normalization with the introduction of HbF. Also, arginine treatment reduced HIF-1α expression as well as ET-1 levels in normoxic BERK mice, supporting a role of decreased NO bioavailability in HIF-1α activation. The present in vivo studies show that reduced inflammation and increased NO production in normoxic BERK mice (expressing HbF or treated with arginine) are distinctly associated with suppression of HIF-1α activation and inhibition of vasodilators, resulting in improved microvascular and hemodynamic parameters in the BERK model of sickle cell disease. The unique feature of inflammation in SCD is that it can be ameliorated by increased HbF, thereby coupling HbS polymerization/sickling to NO depletion, HIF-1α expression and inflammation in this disease. Disclosures: No relevant conflicts of interest to declare.

Microparticles As Biomarkers Of Osteonecrosis Of The Hip In Sickle Cell Disease

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2226-2226
Author(s):  
Anne M Marsh ◽  
Raymond Schiffelers ◽  
Ginny Gildengorin ◽  
Frans A Kuypers ◽  
Carolyn Hoppe
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Vascular Occlusion ◽  
Predictive Biomarker ◽  
Acute Chest Syndrome ◽  
Mobility Limitations ◽  
Cell Disease ◽  
The Past ◽  
D Dimer

Abstract Introduction Sickle cell disease (SCD) is the most common cause of osteonecrosis of the femoral head (ONFH) in children. ONFH is a debilitating condition that is associated with mobility limitations, chronic pain, and an impaired quality of life. While the mechanisms that cause ONFH remain unknown, ischemia from recurrent microvascular occlusion is likely to play a role. Vascular occlusion may result directly from obstruction by sickled cells, or indirectly via complex interdependent pathways characterized by sustained endothelial activation, chronic inflammation, and coagulation. Microparticles (MP) are small, cell membrane-derived vesicles generated in response to cellular activation, injury or apoptosis. MPs have emerged as potential modulators of inflammation and thrombosis and have been found to be elevated in patients with ONFH in the general population. Objective This pilot study examined whether microparticle levels in patients with SCD who have ONFH differ from SCD patients without ONFH, as well as healthy African American (AA) controls. Methods Subjects were recruited at their baseline status and were excluded if they had been transfused within the past 30 days, hospitalized for a vaso-occlusive pain episode, acute chest syndrome, fever or surgery within the past 30 days, or had bony lesions of the femur or hip due to causes unrelated to SCD. For MP analysis, whole blood was collected in sodium citrate tubes and centrifuged for 15 minutes at 1500 x g at 20° C to generate platelet poor plasma. Aliquots of the plasma were immediately frozen and stored at -80° C until the time of MP analysis. 300 μl samples were diluted in PBS and centrifuged at 10000 x g for 1hr and the supernatant was centrifuged at 100,000 x g for 2 hr. The pellet was re-suspended in 1 mL of PBS and subjected to nanoparticle-tracking analysis to determine concentration and size. Additional laboratory biomarkers of inflammation and coagulation, including highly-sensitive C-reactive protein (hs-CRP), von Willebrand factor antigen (vWF Ag), tissue factor (TF), and D-dimer were analyzed for differences between groups. Analysis of variance was used to compare MP and biomarker levels between the three groups. The institutional review board at Children's Hospital & Research Center Oakland approved the study protocol and written informed consent was obtained from all participants. Results Characteristics of the 30 subjects enrolled are shown in Table I. Total microparticle levels in ONFH(+) patients were 2.3-fold higher than in ONFH(-) patients, and 2.5-fold higher than in AA controls (Figure 1). Mean MP levels for ONFH(+) patients, ONFH(-) patients, and AA controls were 4.55 x 1010, 1.99 x 1010, and 1.85 x 1010, respectively. Microparticle levels in ONFH(-) SCD patients did not differ from AA controls. There were no statistically significant differences in hsCRP, vWF Ag, TF, or D-dimer levels between the ONFH(-) and ONFH(+) groups. Conclusions The results of this study demonstrate significantly elevated MP levels in individuals with SCD who have ONFH. Additional studies are needed to better understand the mechanistic effects of MPs on the development of ONFH and to determine whether MP levels may be useful as a predictive biomarker for early disease detection. This publication was supported by NIH/NCRR UCSF-CTSI Grant Number UL1 RR024131. Disclosures: No relevant conflicts of interest to declare.

High Percentage of Evanescent Red Cell Antibodies in Patients with Sickle Cell Disease Highlights the Need for a National Antibody Database

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3572-3572
Author(s):  
Marisa B Marques ◽  
Robinna G Lorenz ◽  
Lance A Williams
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Low Frequency ◽  
Red Cell ◽  
Cell Disease ◽  
Positive Antibody ◽  
Clinically Significant ◽  
Antibody Screen ◽  
Transfusion Reactions

Abstract Introduction: From 20 to 50% of patients with sickle cell disease are alloimmunized to red cell antigens from transfusions and/or pregnancies. Pre-transfusion testing (e.g. antibody screening) is essential to avoid hemolytic transfusion reactions from clinically significant antibodies, such as those to Rh, Kell, Duffy and Kidd antigens, among others. Unfortunately, alloantibodies may evanesce over time, becoming undetectable or even leading to a negative antibody screen. Furthermore, antibodies to low frequency antigens in the donor pool, mostly from Caucasians, may not be detected because they are not typically expressed on standard reagent red cells used for testing. Both of these facts contribute to the risk of hemolytic transfusion reactions despite negative pre-transfusion screening. To mitigate this risk, individual transfusion services maintain antibody histories of all patients indefinitely, and must refer to them prior to issuing every unit for transfusion. Patients and Methods: We analyzed data collected from the electronic medical records of every adult (19 and older) patient with sickle cell disease who had one or more positive antibody screen in our institution during a 2-year period from 2013-2015 to determine: 1. antibody specificities; 2. percentage of patients with at least one non-reacting alloantibody; 3. specificities of evanescent antibodies; and 4. number (percentage) of patients with antibodies to low frequency antigens. Results: We identified 71 patients, of which 5 were excluded because they only had a cold-reacting anti-M (n=2), anti-Lewis, a warm autoantibody (WAA), or a High Titer Low Avidity (HTLA) antibody (n=1 each). Thus, 66 patients were included in the analysis (62% females). The age range of the study-group was 19-59 years old (mean ± SD, 33 ± 11 years), similar between males and females (p = 0.43). Males tended to have an antibody screen ordered more often during the study-period, with a trend toward statistical significance (9.4 versus 5.0 times; p = 0.06). The total number of clinically significant alloantibodies was 218 with mean and median number per patient of 3.3 and 3.0, respectively. In addition, 16 patients also had a WAA. Anti-E was the most common alloantibody, followed by anti-C and anti-K; the table shows the antibodies identified at least once in 10% or more of the patients, as well as how often they were not reacting. Of 9 patients with anti-D, 7 were Rh positive, consistent with the propensity of African-Americans to express a D variant. Of note, 30 patients (45%) had antibodies to one or more low frequency antigen such as Cw, V, Vs, Goa, Jsa, Kpa, Lutheran b, Wra, and Ytb; 6 patients (9%) only had alloantibody(ies) to these antigens. Only 12 patients had a positive antibody screen every time they were tested. However, they had significantly fewer tests (average and median of 2, range of 1-6) compared with 54 patients with at least one antibody screen completely negative (average and median of 5 tests, range of 1-30) (p < 0.0001). Table 1.Rh systemKellDuffyKiddMNSsOtherAntibody specificityDCEVGoaKJsaFyaFybJkbSAUSNumber of patients93040147201518912177Percentage of total antibodies4%14%18%6%3%9%7%8%4%5%8%3%Times not reacting516218312121078123Percent evanescent56%53%53%57%43%60%80%56%78%67%71%43%AUS-antibody of unknown specificity; Fya-Duffy a; Fyb-Duffy b; Jkb-Kidd b; Conclusions: Our results demonstrate that 81% of patients with sickle cell disease with a history of red cell alloantibodies had at least one test in which the antibody was not detectable. Delayed hemolytic transfusion reactions are the major risk of evanescent alloantibodies not known to the transfusion service preparing the units. Such reactions may even be fatal, especially if not promptly recognized, since they may be confused with a pain crisis. In addition, we noticed that almost half of the patients had antibodies to low frequency antigens that could have been missed during pre-transfusion testing. Considering that patients with sickle cell disease often suffer from lack of continuity of care, unawareness of their antibody history may lead to life-threatening transfusion reactions. We suggest that a national, or even regional, database of red cell alloimmunization in this patient population is warranted for increased transfusion safety. Disclosures No relevant conflicts of interest to declare.

Phenotype Matching of Donor Red Blood Cell Units for Nonalloimmunized Sickle Cell Disease Patients: A Survey of 1182 North American Laboratories

2005 ◽  
Vol 129 (2) ◽  
pp. 190-193 ◽  
Author(s):  
Melanie Osby ◽  
Ira A. Shulman
Keyword(s):  
Sickle Cell Disease ◽  
Blood Cell ◽  
Sickle Cell ◽  
North American ◽  
Red Cells ◽  
Red Cell ◽  
Cell Disease ◽  
Cell Antigen ◽  
Red Cell Antigens ◽  
Matched Donor

Abstract Context.—The transfusion of donor red blood cell units (RBCs) that lack certain red cell antigens (such as C, E, and K) when the corresponding antigens are absent from the recipient's red cells has been shown to reduce the risk of red cell alloimmunization in sickle cell disease patients. However, data are limited regarding the extent to which transfusion services routinely perform red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients, and then use that information to select donor RBCs lacking 1 or more of the red cell antigens that the patient's red cells do not express. Objective.—To determine the extent to which transfusion services routinely perform red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients, and then use that information to select donor RBCs lacking 1 or more of the red cell antigens that the patient's red cells do not express. Design.—An educational subsection of a College of American Pathologists Proficiency Testing Survey (J-C 2003) assessed transfusion service practices regarding performance of red cell antigen phenotype testing of nonalloimmunized sickle cell disease patients and how transfusion services use this information for the selection of donor RBCs. The data analysis of the survey included 1182 North American laboratories. Results.—Data from 1182 laboratories were included in the survey analysis, of which the majority (n = 743) reported that they did not routinely perform phenotype testing of sickle cell disease patients for antigens other than ABO and D. The other 439 laboratories reported that they did routinely perform phenotype testing of sickle cell disease patients for antigens in addition to ABO and D. The majority of these 439 laboratories (three fourths; n = 330) reported that they used these patient data for prophylactic matching with donor RBCs when sickle cell disease patients required transfusion. When phenotype-matched donor RBCs were used, the antigens most commonly matched (85% of the time) were C, E, and K. Conclusions.—The majority of North American hospital transfusion service laboratories do not determine the red cell antigen phenotype of nonalloimmunized sickle cell disease patients beyond ABO and D. Those laboratories that do determine the red cell phenotype of nonalloimmunized sickle cell disease patients beyond ABO and D most commonly match for C, E, and K antigens when phenotype-matched donor RBCs are used.

Prevalence of Sickle Cell Anemia In Eastern India

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 4822-4822
Author(s):  
Abhijit Chakraborty ◽  
Jayasri Basak ◽  
Deboshree Majumdar ◽  
Soma Mukhopadhyay ◽  
Sagnik Chakraborty ◽  
...  
Keyword(s):  
Risk Factor ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Sickle Cell Anemia ◽  
West Bengal ◽  
Conflicts Of Interest ◽  
Acute Chest Syndrome ◽  
Red Cell ◽  
Cell Disease ◽  
Cell Counts

Abstract Abstract 4822 Background: Sickle cell disease is an inherited disorder of hemoglobin synthesis. This is due to replacement of Valine for Glutamic Acid in position six of the Beta globin chain of hemoglobin. This genetic alteration yields unstable RBC which lasts for 10–20 days. In stressful conditions the cells become sickle shaped and get lysed. There are about 20 million people with sickle cell disease in India. During January 2009- May2010 camps were held in various parts of West Bengal, Jharkhand, Chattisgarh. Along with various mutations of thalassemia, we also observed sickle cell anemia among them. This triggered our interest to study the spectrum of the sickle mutation co-inheritant with different mutations such as Homozygous Sickle Cell, Sickle Cell-Beta0 Thalassemia, Sickle Cell-Beta+ Thalassemia, Severe β+ thalassemia genes, Moderate β+ thalassemia genes, Mild β+ thalassemia genes Sickle cell-HbE Thalassaemia, Sickle cell-HPFH Thalassaemia, in said part of India. Since Indian patients with SS disease had higher hemoglobin, red cell counts and higher HbF levels and lower HbA2, MCHC, MCV, and reticulocyte counts, hence a high hemoglobin is a risk factor for painful crises and may also be a risk factor for avascular necrosis of the femoral head, proliferative sickle retinopathy, and acute chest syndrome. Methods: We have screened 332 individuals in eastern part of India during the period January 2009- May 2010. 3ml of peripheral blood was collected in EDTA vial from each individual. NESTROFT (Naked Eye Single Tube Red Cell Osmotic Fragility Test) was performed on spot. Then Complete Blood Count was done within 24 hours of collection. HPLC (High Performance Liquid Chromatography) was performed to identify the samples for confirmation. In our observation in case of sickle cell anaemia HbF (Fetal haemoglobin), Hb (haemoglobin), MCV (mean corpuscular volume) values ranges between 0–10 %, ≤7-10g/dl, 65–90fl respectively. ARMS (Amplification Refractory Mutation System) PCR (polymerase chain reaction) was done to confirm the mutation. Result: Conclusion: Of the total samples collected in the camps held at various places of Jharkand, Chattisgarh & West Bengal 87 of them was carriers of sickle cell anemia. There was 7 homozygous (SS), 14 sickle beta, 12 double heterozygous for HPFH (High Persistance of Fetal Hemoglobin) & sickle cell anemia. In conclusion, the manifestations of sickle cell disease are influenced by a variety of other genetic and environmental factors. The occurrence of the disease against different genetic and environmental backgrounds provides experimental models that contribute to understanding the variability in clinical and hematological expression of the disease. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Assessment of Average Hematocrit of Red Cell Units for Erythrocytapheresis Procedure in Sickle Cell Disease

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4285-4285
Author(s):  
Veronica Cook ◽  
Teresa Munson ◽  
Elpidio Pena ◽  
Ashok Raj
Keyword(s):  
Sickle Cell Disease ◽  
Blood Cell ◽  
Sickle Cell ◽  
Red Blood Cell ◽  
Small Sample ◽  
Red Cells ◽  
Red Cell ◽  
Limited Data ◽  
Cell Disease ◽  
Consensus Report

Abstract Background: Erythrocytapheresis, or red blood cell exchange (RCE) is a non-invasive procedure in which a patient's erythrocytes are removed from the bloodstream while being replaced with erythrocytes from blood donors. RCE is commonly used as a transfusion technique in patients with sickle cell disease (SCD) to help treat and prevent complications associated with sickling of erythrocytes and iron overload. The AABB consensus report (1) outlines the procedural guidelines for RCE including appropriate indications and ideal forms of vascular access. However, the guidelines make no recommendation for determining the hematocrit (Hct) of the red cell bags for the procedure. Institutions take several different approaches to determine how many red cell units to exchange. The number of units needed depends on the volume and Hct of the individual units as well as the patient's pre-procedure Hct and HbS levels, height, weight, and the desired HbS and Hct targets. Red cell units are routinely labeled with volume, but are not generally labeled with Hct. The AABB consensus report (1) states that some institutions use an estimated Hct of 56% to 57% for each unit. The report rationalizes the use of an estimated Hct for input for the RCE, by citing the approximated Hct of bags of red cells (55% to 60%) with additive solution produced from whole blood donation, based on limited data. The goal of our study was to determine the average Hct on the red cell units used for RCE. Methods: This study used a retrospective chart review to investigate the Hct of red cell units during a RCE in a calendar year. Our institution uses pre-storage leuko-reduced red blood cells units in citrate phosphate dextrose adenine (CPDA-1) and adsol preservative (AS-1), which are 21 days old or less for RCE. The average Hct of the bags of red cells infused during the procedure was determined by accessing each bag for a small sample of blood to determine the Hct. Data was excluded if the patient did not meet standard weight requirements (&gt; 30 kg) or required additional treatment protocols including the use of washed cells or machine priming. Results: A total of 297 encounters were recorded for 30 different patients. A total of 1953 bags (approximately 517 liters of red cell units in volume) were administered. Data from the encounters were used to calculate measures of central tendency. The average calculated Hct for each encounter was 63.3%, with a median and mode Hct being 63% and 62%. The range of Hct from the bags was 54.6% to 72.9%. The average Hct of the bags ranged from 60.6% (in March) to 64.8 % (in July). Conclusions: Our study suggests a higher average Hct of transfused red cell units than stated in the AABB consensus report (1), which was based on limited data. Our findings indicate that a standardized average of 63.3%, would be appropriate for our institution. Conversely, our findings also signify that the standardized average Hct must be determined in each institution prior to their application for RCE. However, our data also reveals that it is possible to subject patients to estimates as far as 9.7% above and 9.6 % below the true average Hct of the red cell bags used. The process of determination of Hct for each of the red cell units increases the time of pre-service activities, laboratory costs, and the overall infusion center time for the patients leading to higher costs per infusion. Consequently, using a standardized average of the Hct would result in cost savings. We have therefore adopted the practice of using the standardized average of Hct of 63.3% for RCE in our patients. Reference: 1. Biller E, Zhao Y, Berg M, Boggio L, Capocelli KE, Fang DC, Koepsell S, Music-Aplenc L, Pham HP, Treml A, Weiss J, Wool G, Baron BW. Red blood cell exchange in patients with sickle cell disease-indications and management: a review and consensus report by the therapeutic apheresis subsection of the AABB. 2018 Aug;58(8):1965-1972. doi: 10.1111/trf.14806 Disclosures Munson: Terumo Medical Corporation: Consultancy, Honoraria, Speakers Bureau. Raj: Terumo Medical Corporation: Honoraria, Speakers Bureau; Global biotherapeutics: Speakers Bureau; Forma therapeutics: Consultancy.

Characteristics of Sickle Cell Disease Children Having Elevated Thrombin Potential

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4762-4762
Author(s):  
Denis F Noubouossie ◽  
Phu-Quoc Le ◽  
Laurence Rozen ◽  
Dominique Willems ◽  
Mahadeb Bhavna ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Cell Disease ◽  
Normal Children ◽  
Clotting System ◽  
Younger Age ◽  
The Mean ◽  
D Dimer ◽  
Age Category

Abstract Abstract 4762 Introduction: Abnormalities of the clotting system are often observed in sickle cell disease (SCD). In addition to activation of coagulation, increased thrombin generation (TG) has recently been demonstrated in SCD children Aim of the study: To characterize the group of SCD children with increased TG in terms of clinical and biological parameters. Material and methods: TG was performed in the platelet-poor plasma of 97 SCD children at steady-state and 80 controls aged between 2 and 20 years. TG was triggered using 1 pM tissue factor and 4μM synthetic phospholipids with thrombomodulin to activate the protein C/protein S anticoagulant pathway. The Endogenous Thrombin Potential (ETP) and the peak height were analyzed. As these parameters increase with age in normal children, controls were distributed in 4 categories of age: [2–5], [6–10], [11–15] and [16–20] years. The mean ETP and the mean peak were calculated for each age category. A ratio for ETP (r ETP) and a ratio for the peak (r Peak) were defined for each control and patient as follows: individual ETP/ mean ETP and individual peak/ mean peak according to age category. Overall mean of r ETP and r Peak was then calculated such as to eliminate bias due to age. This calculated mean was 1.00 (0.39 – 1.61) for r ETP and 0.99 (0.28 – 1.81) for r Peak in controls. TG was considered abnormal if r ETP or r Peak value was above the mean + 2SD of controls (r ETP≥ 1.62 and r Peak≥ 1.82). Clinical and laboratory parameters were compared between SCD children having normal or increased ratios using the Mann Whitney test for numbers or the Fisher's exact test for proportions. P < 0.05 was considered significant. Results and Discussion: Overall 48 (49.4 %) patients showed either high r ETP or high r Peak whereas both parameters were increased in 31 (31.9 %) patients. As shown in Tables I and II, SCD children with elevated ratios were characterized by a younger age, shorter duration of hydroxyurea (HU) treatment, lower total hemoglobin level, higher reticulocyte and monocyte counts, higher LDH and D-dimer levels and a trend to increased procoagulant microparticle level (PMP) as compared with those having normal ratios. The higher D-dimer level in the group with abnormal ratios indicates that these children also manifest a higher degree of coagulation activation than those with normal ratios. Differences observed with markers of hemolysis are consistent with other reports suggesting a link between hypercoagulability and high hemolytic rate in SCD. The borderline significance of PMP is probably due to the use of exogenous phospholipids in TG which reduces the sensitivity of the test to endogenous phospholipids at the surface of PMPs. Conclusion: According to our study, Elevated Thrombin Potential is more frequently encountered in SCD children of younger age, with a shorter duration of HU treatment and with increased rate of hemolysis. These observations together with elevated D-dimer level seem to characterize SCD children with a hypercoagulable state. Disclosures: No relevant conflicts of interest to declare.

Red Cell Alloimmunization in Sickle Cell Disease: Benefit of Extended Crossmatching in Adults

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4761-4761 ◽  
Author(s):  
Dianne Pulte ◽  
Julie Kay ◽  
Mary Harach ◽  
Nguyet Le ◽  
Jay H. Herman
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Antibody Formation ◽  
Exchange Transfusion ◽  
Conflicts Of Interest ◽  
High Rate ◽  
Red Cell ◽  
Cell Disease ◽  
Phenotype Matching ◽  
Positive Screen

Abstract Abstract 4761 Background: Patients with sickle cell disease (SCD) receive frequent transfusions and have been observed to have a high rate of transfusion reactions and alloantibody formation after transfusion. Alloimmunization to antigens of the Rh system, Kell, Duffy, MNSs, and Kidd are most common. It has become accepted practice at most sickle cell centers to match for C, E, and Kell antigens in order to prevent alloimmunization. Most studies of the effectiveness of red cell (RBC) phenotype matching have been in pediatric patients and have shown a decrease in alloimmunization beyond those specific antigens that are pre-emptively matched. Leukoreduction (LR) of blood products is known to decrease HLA alloimmunization and may also reduce the risk of RBC antibody formation. It is also unclear whether there is value in continuing phenotype matching beyond the pediatric age and whether new RBC antibodies may be prevented by LR, independent of phenotype matching. Patients with SCD at our institution are routinely matched for C, E, and Kell antigens and given leukoreduced blood. Here, we study our past experience in reducing the frequency of new alloantibody formation. Methods: We reviewed charts of patients with SCD, including sickle cell anemia, sickle/thalassemia, and SC disease, who were transfused at Thomas Jefferson University (TJU) and had documentation of presence or absence of alloantibodies on presentation to our center. Data extracted from chart included patient's age, disease type, known antibodies, and time of first documentation of antibody. Antibodies were considered to be definitely unrelated to transfusion at TJU if they were present before first transfusion at TJU or if a previous screen not showing the antibody in question had been performed and no transfusions given between that screening and the development of the relevant antibody. LR was used routinely at TJU starting in 2003 and was used in selected cases, including many sickle patients, earlier. In 1996, TJU began crossmatching for C, E, and Kell antigens. Results: 68 charts of patients with SCD transfused at least once at TJU were reviewed, including 8 patients undergoing routine exchange transfusion for stroke prevention. Of these, 33 (48.5%) had no alloantibodies detected at any time. Of the remaining 35, 16 had 1 antibody, 8 had 2 antibodies, and 11 had 3 or more antibodies, including 3 patients with 8–10 each. A total of 92 antibodies were identified among these 35 patients, 60 of which were not related to transfusion at TJU. Of the remaining 32 antibodies, the most common antibodies identified were C (5 instances) and E (6 instances). Antibodies to Kell, Fya, and Jkb developed in 3 patients apiece. Two instances each of C, E, and Kell antibodies developed after the initiation of crossmatching for these antigens, but in all but one case, the records suggested that the antibody was most likely developed by transfusion at an outside institution not practicing phenotype matching, but this could not be confirmed (i.e. the patient was not transfused at TJU for >1 year prior to the positive screen appearing, but there were no screens in between to identify whether the antibody became evident ). One instance of C developed after emergency transfusion without extended crossmatch and thus the antibody likely developed from transfusion at TJU. Patients who developed antibodies had a higher number of transfusions than non-immunized patients (median 117 vs 74 units, respectively) and were older (38 vs 35 years, respectively), but neither was statistically significant (p>0.1 in each). Of 8 patients undergoing chronic RBC exchange transfusion, 3 have no alloantibodies, 3 had antibodies that developed from transfusion elsewhere, 1 had a new alloantibody but had prior alloimmunization and 1 developed new alloantibodies at TJU. Conclusions: Our results confirm that C, E, and Kell continue to be the most common antigens leading to alloimmunization in transfused adult SCD patients. A combination of LR and extended phenotype matching appears to be effective in reducing antibody formation compared to historical reports. Our retrospective study has limitations, notably the possibility that patients may have been transfused at other institutions, which may not use phenotype matching or leukoreduced products. Further prospective studies are indicated to aid in determining whether phenotype matching is justified in adult sickle cell patients in the face of growing global LR. Disclosures: No relevant conflicts of interest to declare.

Renal Disease in Sickle Cell: Clinically Varied and Associated with Increased Mortality

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 90-90
Author(s):  
Sabarish Ayyappan ◽  
Paul Drawz ◽  
Mehdi Nouraie ◽  
Mariana E Hildesheim ◽  
Yingze Zhang ◽  
...  
Keyword(s):  
Renal Function ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Multivariate Analyses ◽  
Conflicts Of Interest ◽  
Laboratory Data ◽  
Red Cell ◽  
Cell Disease ◽  
Cell Destruction ◽  
Increased Risk

Abstract Abstract 90 The Walk-Phasst Study of sickle cell disease (SCD) affords a unique opportunity to examine renal function in a large number of adults with SCD. Extensive clinical and laboratory data were obtained on 463 adults with HbSS and 127 adults with HbSC. Where possible, correlates for estimated glomerular filtration rate (eGFR, calculated by the 4-value MDRD equation) and albuminuria/proteinuria were also evaluated in historical data, from SS adults in the CSCCD cohort and the Multicenter Study of Hydroxyurea (MSH) in sickle cell disease. Adjusted decline in eGFR was more rapid in SS compared with SC, at −2.6 and −0.92 ml/min/1.73 m2/year, respectively (p<0.001). In SS, similar declines in cross-sectional eGFR with age were seen in adults in the CSCCD (n=705) and MSH (n=298) cohorts, at −2.9 and −1.9 ml/min/year (BSA corrected), respectively. Multivariate analysis of the SS cohort in of Walk-Phasst revealed that depressed eGFR values were associated with an elevated estimated pulmonary arterial systolic pressure (as reflected in a higher tricuspid regurgitant jet velocity, measured by echocardiogram, p=0.007) and with evidence for inflammation (an elevated white blood cell count, p=0.018). In SC adults, in contrast, lower eGFRs were primarily associated with a diminished erythroid reserve (depressed absolute reticulocyte counts, P=0.005). Albuminuria (≥30 mg albumin/gm creatinine) was detectable in 66 and 41 % of adults with HbSS and HbSC in Walk-Phasst (185/287 evaluable SS and 25/61 evaluable SC, p=0.001). In Walk-Phasst, albuminuria in SS was associated with evidence of increased red cell destruction (lower total hemoglobin (P=0.07), higher LDH (P<0.001), and higher reticulocyte count (P=0.017)). In SC, albuminuria was associated with a higher LDH (P=0.01). 159/657 (24%) of adult SS subjects in the CSCCD cohort had trace to 4+ proteinuria, using a method (urine dipstick analysis) that is less sensitive and less quantitative than the albumin-to-creatinine ratio used in Walk-Phasst. Multivariate analyses again suggested a strong association between a depressed Hgb and proteinuria (P<0.001) in CSCCD, and LDH was also associated with proteinuria, in univariate analyses (P<0.001). In Walk-Phasst the absence of albuminuria in all subjects with SCD was associated with lesser mortality in multivariate analyses (Hazard ratio 0.62 (0.4–0.9, P=0.02). No similar association was seen between eGFR and mortality. Subjects with SS in Walk-Phasst had depressed serum bicarbonate levels, of 23.8±3.4 compared with 24.7±3.2mEq/dL in SC (p<0.005) and 24.8±3.3 mEq/dL in the non-CKD general population (Shah et al, 2009). In multivariate analyses, acidemia was associated with both increased destruction and decreased production of red cells, e.g. higher EPO (P=0.003) and total bilirubin levels (P<0.001), but lower reticulocyte counts (P=0.06). Impaired physiologic functioning in acidemic subjects with HbSS, manifest as a depressed 6MWD (P<0.001) and a lower eGFR (P<0.001), was seen. No effect of bicarbonate level on mortality in SCD patients was evident in Walk-Phasst. In conclusion, renal function is perturbed in sickle cell syndromes in several ways, including more rapid decrement in eGFR, highly prevalent albuminuria, and, in SS, marked abnormalities in acid-base balance. Albuminuria is associated with anemia in two large cohorts of sickle cell disease patients and, in Walk-Phasst, with evidence for enhanced red cell destruction. Importantly, albuminuria correlated with an increased risk for mortality in sickle cell disease. (We acknowledge the many contributions made by the Walk-PHASST Investigators: Badesch DB, Barst RJ, Castro OL, Girgis RE, Gibbs JS, Goldsmith JC, Hannoush H, Hassell KL, Kato GJ, Krishnamurti L, Lanzkron S, Machado RF, Morris CR, Novelli EM, Rosenzweig EB, Sachdev V, Schraufnagel DE, Taylor JG 6th.) Disclosures: No relevant conflicts of interest to declare.

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