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.

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.

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.

Variant RH in Patients with Sickle Cell Disease Is Associated with Clinically Significant Alloimmunization

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3239-3239
Author(s):  
Stella T Chou ◽  
Tannoa Jackson ◽  
Sunitha Vege ◽  
David Friedman ◽  
Connie M Westhoff
Keyword(s):  
Sickle Cell Disease ◽  
Clinical Significance ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Antibody Detection ◽  
Cell Disease ◽  
Hemoglobin S ◽  
Variant Alleles ◽  
Clinically Significant ◽  
Rbc Transfusion

Abstract Abstract 3239 Red blood cell (RBC) transfusion is a key treatment for patients with sickle cell disease (SCD), but remains complicated by the high incidence of RBC immunization. Despite provision of phenotypic Rh D, C, and E antigen-matched donor RBCs, patients continue to develop Rh antibodies. In many cases, these antibodies are considered autoantibodies with specificities for D, C, and e antigens because the patient's own RBCs type serologically positive for the corresponding antigen. Recent evidence is emerging that Rh alloimmunization within populations of African origin is complicated by the genetic diversity of this locus. Individuals of African ancestry often carry RH alleles that differ from those defined as conventional alleles that are common in Europeans and other ethnic groups. These “variant” alleles encode Rh proteins, often with multiple amino acid changes, that either lack common epitopes or produce novel immunogenic epitopes. The clinical significance of Rh alloimmunization in patients with SCD with variant RH genes is largely unknown. In the present study, we performed RH genotyping in 212 patients with SCD to determine prevalence of RH variants, the association with Rh alloimmunization, and the clinical significance measured by changes in hematologic parameters at time of antibody detection. RH genotyping was performed by polymerase chain reaction (PCR) amplification using RHD-specific and RHCE-specific primers designed in the flanking intronic regions and analyzed by direct sequencing of exons, and/or a combination of multiple PCR-restriction fragment length polymorphism (RFLP) assays and by RHD and RHCE BeadChip arrays. We identified variant RH alleles in 88.7% (188/212) of patients with SCD. Twelve different RHD and 13 RHCE alleles encoding variant Rh D, C, and e antigens were represented in this cohort of patients. In 172 patients with >1 RBC transfusion (median 125 units), 55 antibodies were identified with Rh specificity despite antigen-positive status (28 anti-D, 16 anti-e, 9 anti-C, and 2 anti-E). RH genotypes revealed 47.3% of these antibodies developed in patients who lacked the corresponding conventional RH allele, and would be considered Rh alloantibodies. In 43.6%, RH genotypes predicted expression of the conventional antigen to which the antibody was directed, suggesting these were potentially autoantibodies. However, these patients had at least one other RH allele that was altered. This may suggest that the presence of one variant protein potentially changes the Rh complex in the membrane, and carrying at least one conventional RH allele is not necessarily protective against production of Rh specific antibodies. In the remaining 9.1%, we detected no variant RHD or RHCE alleles, and complete gene sequencing is in progress to confirm the absence of novel mutations. Importantly, to determine clinical significance, we evaluated whether Rh antibodies in patients carrying variant alleles caused decreased transfused RBC survival by comparing the patient's hematologic parameters at the time of antibody detection with the baseline pre-transfusion parameters. In all but 4 cases, Rh antibodies in antigen-positive patients occurred in chronically transfused patients. Therefore, baseline values were determined from the average pre-transfusion hemoglobin, hematocrit and % hemoglobin S level for the 6–12 months preceding antibody detection. Compromised transfused RBC survival was determined by a lower hemoglobin/hematocrit or higher % hemoglobin S level at time of antibody formation compared to the patient's baseline. Forty percent of antibodies were associated with delayed hemolytic transfusion reactions or decreased transfused RBC survival. Our data suggest that the high prevalence of variant RH alleles in patients with SCD is associated with clinically significant immunization. Discrimination of allo- versus auto- antibodies in this chronically transfused patient population presents a significant technical challenge and suggests a role for RH genotyping in the clinical evaluation of Rh antibodies and to improve RBC matching. Importantly, in this study Rh antibodies in patients with variant RH often compromised transfused RBC survival and, therefore, were clinically significant and may be targets for prevention strategies analogous to standard phenotype matching for C, E, and K. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Alloimmunization in Patients with Sickle Cell Disease in French Guiana

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Narcisse Elenga ◽  
Loic Niel
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Medical Records ◽  
French Guiana ◽  
Red Cell ◽  
Cell Disease ◽  
Hemolytic Transfusion Reaction ◽  
Delayed Hemolytic Transfusion Reaction ◽  
Clinically Significant ◽  
Transfusion History

This study in French Guiana assessed the frequency of alloimmunization to red cell antigens in sickle cell disease patients over 1995–2011 and identified the most common antibodies. A retrospective analysis of the transfusion history and medical records of 302 patients showed that 29/178 transfused patients had developed alloantibodies (16%). The most frequent alloantibodies were anti-LE1, anti-MNS1, anti-LE2, and anti-FY1 and were developed after transfusion of standard red cell units. The frequency of the clinically significant antibodies in this population of SCD patients was 11% (19/178). The antibodies found on those patients who had delayed hemolytic transfusion reaction were anti-K1, anti-FY1, and anti-MNS3. The strategies used to decrease alloimmunization in French Guiana are discussed.

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.

Use of Genomics for Transfusion Therapy Management in Patients with Sickle Cell Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2324-2324
Author(s):  
Connie M Westhoff ◽  
Stella T Chou ◽  
Kim Smith-Whitley ◽  
David Friedman
Keyword(s):  
Sickle Cell Disease ◽  
Blood Group ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Hla Typing ◽  
Blood Group Antigens ◽  
Dna Testing ◽  
Cell Disease ◽  
Transfusion Therapy ◽  
Clinically Significant

Abstract Abstract 2324 A genomic approach to blood group typing is now possible and high-throughput automated platforms have been developed to test for numerous blood group antigens in a single assay. These methods are reproducible and highly correlated with RBC serologic phenotype. We routinely perform a complete RBC phenotype for clinically significant minor red cell antigens on pre-transfusion samples from patients with sickle cell disease, and we antigen match patients for C, E, and K for transfusion. In this study we compared the historic serologic typing with that predicted from DNA testing for clinically significant antigens in 114 samples from chronically transfused patients with SCD to determine concordance and to evaluate the clinical utility of genotyping for the management of transfusion therapy. Serologic typing was performed by standard methods with licensed commercial reagents. DNA was isolated from WBCs, and minor antigen genotyping was performed with HEA (human erythrocyte antigen) BeadChip (BioArray, Inc). RH genotyping was by a combination of methods including PCR-RFLP, AS-PCR, exon-specific amplification and sequencing, and, for some, Rh-cDNA amplification and sequencing. Comparison of serologic typing with DNA-based testing for thirteen blood group antigens, CcEe, Fya/b, K, Jka/b, MN and Ss, in 114 samples found 8 discrepancies in 1,482 antigens analyzed, for 99.5 % concordance. Discrepancies were in several systems (C, Fy, Ss, and M), and at least one has been confirmed to be a serologic recording error. All are under investigation. DNA-based testing for RH found 54 of 114 patients inherited variant RHD alleles; many also had conventional RHD in trans. Sixteen patients had made anti-D, despite typing as D+. Ten of 35 patients (∼30%) whose RBCs typed as C+ had a hybrid allele encoding variant C antigen. Five had made anti-C, which prompted us to change our protocol so patients with variant C by DNA testing are transfused on a C- protocol. DNA testing found a large amount of diversity in ce-alleles in this population. Seventy-two of 114 patients carried at least one of nine different variant ce-alleles. Ten patients had made anti-e, despite typing as e+, and were homozygous for variant ce-alleles. In total, 49/114 patients with SCD were homozygous for variant RH alleles and were not truly Rh matched for D, C and e antigens by serology. Similar to the way in which HLA typing by DNA has revolutionized bone marrow transplantation by providing a superior alternative to serological testing, we find that minor blood group antigen typing by DNA improves efficiency, reduces cost, and expands antigen matching, especially in the Rh system. Continuing studies are needed to identify more precisely which variant alleles are associated with clinically significant antibody production to improve antigen matching for patients with sickle cell disease. Disclosures: No relevant conflicts of interest to declare.

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 Alloimmunisation in sickle cell patients of western Odisha: A tertiary care centre study

2021 ◽  
Vol 11 (2) ◽  
pp. 280-283
Author(s):  
Yespal Sharma ◽  
Chitta Ranjan Prasad ◽  
Susmita Behera
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Tertiary Care ◽  
Red Cell ◽  
Care Centre ◽  
Cell Disease ◽  
Tertiary Care Centre ◽  
Naturally Occurring ◽  
Patient Load ◽  
Clinically Significant

RBC carries numerous protein and carbohydrate antigens on their surface. Out of 347 red cell antigens recognized by international society of blood Transfusion, 308 antigens are clustered in 36 blood Group systems. Except naturally occurring anti-A and anti-B antibodies all others are unexpected. Out of these some like Duffy, Kell, Kidd, MNS, P and certain Rh types are considered clinically significant. Only few studies for prevalence of irregular red cell alloantibody have been done. Those studies were done either in general population or in thalassemia patients. Few studies were done on sickle cell disease patients but all are outside India and those are significant. But no studies have been done till now on prevalence of alloantibody in sickle cell disease patients in India. Again the western part of Odisha is with high patient load of sickle cell disease. This study is very useful for this part of Odisha as complication due to the alloantibody can be managed properly. Both the patients and the clinician will be benefited by this study.

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