High-Throughput DNA Analysis for Red Blood Cell Antigens Facilitates the Transfusion Support with Antigen-Matched Blood in Sickle Cell Disease Patients.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 555-555
Author(s):  
Lilian Castilho ◽  
Ghazala Hashmi ◽  
Marion E. Reid ◽  
Tasmia Shariff ◽  
Michael Seul ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Blood Group ◽  
Sickle Cell ◽  
High Throughput ◽  
Dna Analysis ◽  
Blood Type ◽  
Blood Group Antigens ◽  
Nucleotide Polymorphisms ◽  
Cell Disease ◽  
Fast Procedure

Abstract Background: Transfusion dependent patients as those with Sickle Cell Disease (SCD) patients become alloimmunized and have the potential to form additional antibodies with such frequency that antigen-negative blood is preferred to prevent further alloimmunization. Blood group genotyping is playing a supporting role in the routine blood banks, especially for provision of antigen-matched blood for these patients. However, current techniques for genomic typing are all labor-intensive and require manual set up and analysis by gel electrophoresis. As a result, DNA microarrays are being developed for the single nucleotide polymorphisms (SNPs) detection in the blood group genes to provide a fast procedure and an automated analysis of numerous blood group polymorphisms. We evaluated the usefulness of DNA microarray to provide a means to precisely match donor blood to the antigen-negative type of SCD patients. Method: A total of 12 DNA samples from patients with SCD (homozygous for HbS) and 84 DNA samples from blood donors, were analyzed by the HEA Beadchip (Hashmi et al, 2005) containing a total of 18 SNPs (FYA/B, FY-GATA, FY265, DOA/B (nt 378, 624, 793), COA/B, LWA/B, DIA/B, SC1/SC2, M/N, S/s, LUA/B, KEL1/2, JKA/B, DO323, DO350, HgbS) in a single reaction. Results: A genotype result was obtained for all SNPs tested on 96 samples within 4 hours of the start of testing. Results obtained by Beadchip analysis in donors were used to provide antigen-matched blood for FYA/B, FY-GATA, FY265, DOA/B, M/N, S/s KEL1/2, JKA/B, for all 12 SCD patients. This technology provided a fast procedure and facilitated the transfusion support with antigen-matched blood in SCD patients allowing the reduction of alloimunization to blood group antigens. Conclusion: This high-throughput DNA analysis has the potential not only to increase the inventory of antigen-negative blood but also to facilitate the matching of RBC component to the recipient’s blood type. It also contributes to the management of transfusions in SCD patients by allowing a more accurate selection of donor units. The application of microarray technology in transfusion medicine may have a tremendous impact on further improvement of the safety of blood transfusion.

scholarly journals Genes Associated with Alloimmunization to Blood Group Antigens in Sickle Cell Disease

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 762-762 ◽  
Author(s):  
Jacqueline N. Milton ◽  
Allison E. Ashley-Koch ◽  
Melanie E. Garrett ◽  
Karen L. Soldano ◽  
Eugene P. Orringer ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Missense Mutation ◽  
Blood Group ◽  
Sickle Cell ◽  
Candidate Gene Approach ◽  
Data Sets ◽  
Blood Group Antigens ◽  
Missense Mutations ◽  
Cell Disease ◽  
Data Set

Abstract BACKGROUND: Alloimmunization to minor blood group antigens is more common in sickle cell disease (SCD) than in the general population. Causes include the high frequency of transfusion as well as phenotypic differences between the largely African-American SCD population and mostly Caucasian blood donors. Alloimmunization, as well as the risk of alloimmunization, results in higher costs as well as reduced availability of and delays in obtaining antigen-matched blood to meet clinical needs. We used a candidate gene approach to determine if specific genetic signatures were associated with alloimmunization and thus could identify patients at high risk for alloimmunization and therefore requiring prospective antigen matching for transfusion. METHODS: Patient data were previously collected through a multicenter study to identify genetic factors associated with SCD complications (Duke and UNC; DU) and through the Cooperative Study of SCD (CSSCD). All subjects were adults with HbSS genotype (DU mean yrs 34.9 ± 12.1, CSSCD mean yrs 29.1 ± 9.5, p < .0001). The DU data set was 43.7% male while the CSSCD data set was 37.1% male (p = .18). A genome-wide association study (GWAS) was conducted with the Illumina 610 BeadChips for ­­­390 individuals (215 DU, 175 CSSCD). Quality control processing of these data was published previously (Solovieff et al, 2010). Additionally, imputation of the DU data set was conducted using IMPUTE2 (Howie et al, 2009) and a global reference panel from 1000 Genomes in order to have consistent genotypes across both studies. Based on previous literature, we studied 255 SNPs in the HLA locus as well as 684 SNPs in 53 genes previously associated with immune responses, totaling 939 SNPs. Additive logistic regression was performed separately for the DU and CSSCD data sets with PLINK (Purcell et al, 2008), controlling for age at enrollment. Results from the two data sets were combined by meta-analysis, using the invariance weight method in METAL (Willer et al, 2010). False discovery rate (FDR) q-values were generated using PROC MULTTEST in SAS v9.4 (SAS Systems). Contingency tables were produced using SAS and association between candidate SNPs and specific antibodies was tested using PLINK. RESULTS: Alloimmunization rates were different in the DU and CSSCD cohorts (30.7% vs. 18.9%, respectively; p = .0075) but were not associated with age or number of transfusions > 0 in either cohort. The most significant genetic associations with alloimmunization (FDR q = .28) occurred for 46 SNPs in the HLA locus and 10 other genes (Table 1). Two of these SNPs were missense mutations in GZMB (granzyme B (granzyme 2, cytotoxic T-lymphocyte-associated serine esterase 1)), one of which (rs8192917) has previously been associated with acute kidney transplant rejection and acute GVHD after stem cell transplant. A missense mutation in TRIM31 (E3 ubiquitin-protein ligase) was also associated with alloimmunization (p = .01). TRIM31 regulates Src-induced anchorage-independent cell growth and has been implicated in antiretroviral defense, cancer and ADHD. Within the DU cohort, we conducted a sub-analysis among only antigen-negative individuals, in whom immunization rates were 15.8%, 14%, 4.5%, 10.2%, 11%, and 8.3% to E, C, K, S, Jkb and Fya, respectively. Regression analysis of all 939 SNPs identified nominally significant associations predicting specific antibody alloimmunization. A missense mutation in PRKCQ (rs2236379) was associated with both anti-E and –C alloimmunization. Additional missense mutations were identified as follows: in TGFBR3 and GZMB with anti-C; in CFH, andTLR6 with anti-K, and in TLR10 with anti-Jkb. CONCLUSIONS: We have identified several immune response genes that are also associated with increased risk of alloimmunization in SCD (nominal p ≤ .006, FDR q = .28). Some associations may arise from the prevalence of alloimmunization to specific antigens. For example, PRKCQ was associated with development of alloantibodies to both E and C antigens, which reside on the same nonglycosylated RH protein. Expanded studies may identify those patients who would benefit from intensive or specific antigen-matching transfusion protocols. TableGenes Associated with AlloimmunizationGene or Locus (ordered by descending p value)SNPs with FDR q = 0.28 SNPs with p ≤ .006GZMB3 (2 missense)3TGFBR242TLR311HLA locus262TGFBR332PRKCQ3CD801VAV21TRIM312 (1 missense)RNF391ZNRD11 Disclosures No relevant conflicts of interest to declare.

Potential Benefits of Extended Genotype Matching to Chronically Transfused Patients with Sickle Cell Disease

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2144-2144 ◽  
Author(s):  
Ricardo Helman ◽  
Rodolfo Cancado ◽  
Mariza A Mota ◽  
Marcia R Dezan ◽  
Jose Mauro Kutner ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Blood Group ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Blood Group Antigens ◽  
Cell Disease ◽  
True Blood ◽  
Erythrocyte Antigen ◽  
Antibody Specificities

Abstract Abstract 2144 Background: Management of RBC alloimmunization in Sickle Cell Disease (SCD) patients has been the subject of much debate, and currently there is no standard approach. Many programs transfuse SCD patients with RBCs that are phenotype-matched for D, C, c, E, e and K. Although these approaches reduce the incidence of alloantibody production, patients still become alloimmunized. Based on this we aimed to identify the rates of alloimmunization in chronically transfused SCD patients and compare the phenotyping with genotyping methods to find a better way to match RBC units to those patients. Methods: We selected 45 SCD patients (homozygous for hemoglobin S) with multiple transfusions, previously phenotyped for ABO, Rh (D, C, c, E, e) and K1. Phenotypes were determined by hemagglutination using gel cards (Diamed® ). Genotypes were determined by a DNA array using the Human Erythrocyte Antigen BeadChip (“HEA”) from Bioarray Solutions. All SCD patients included in this study were in chronical transfusion program; receiving multiple transfusions. The median age was 24y; there were 28(62%) females and 17(37.8%) males. The median of transfusions were 53 (5–78) and 40 (88.9%) patients received more than 20 phenotype-matched units for Rh (D, C, c, E, e) and K1. Results: Of the 45 SCD patients selected, 11 (24.4%) had alloantibodies. The antibody specificities found in these patients were anti-D, -C, -CW, -E, -Jka, -Jkb, -Fya, -Dia, -s. Although the patients were receiving Rh and K phenotype-matched units 8 (17%) of them became alloimmunized to Rh antigens and on those patients we found discrepancies between the previous phenotype and genotype-derived phenotype. Our results showed that the risk of immunization increases in patients over 40 years old (p= 0.05) and with the number of transfusion events. Patients with more than 20 RBC transfusions have a tendency for alloimmunization (p=0.65). We also observed that genotyping was more effective than hemagglutination in determining patient's correct phenotype. Conclusion: Our data show that even with the implementation of Rh and K phenotype-matching in chronically transfused patients with SCD, they still become alloimmunized to other antigens with high immunization risk and also to Rh antigens due to the limitations of the hemagglutination. The relevance of genotype determination of blood groups for the management of multiple transfused patients with SCD has been demonstrated by allowing the determination of the true blood group genotype, by assisting in the identification of suspected alloantibodies and in the selection of antigen-negative. As donor genotyping for the most clinically relevant blood group antigens by automated DNA techniques are becoming available, extended genotype matching should be considered in this group of patients. 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.

Alloantibody Formation in Sickle Cell Disease Patients Receiving Multiple Transfusions.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3795-3795
Author(s):  
Vishwas S. Sakhalkar ◽  
Diana M. Veillon ◽  
James D. Cotelingam ◽  
Gloria C. Caldito ◽  
Deborah M. McCaskill ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Blood Type ◽  
Blood Group Antigens ◽  
Adult Males ◽  
Cell Disease ◽  
Chi Square ◽  
Exact Test ◽  
Number Of Patients ◽  
Patient Groups

Abstract Aim: To study allosensitization in our sickle cell disease (SCD) patients before and after instituting the practice of transfusing C, E, K blood type negative (CEKneg) packed red blood cell (pRBC) units. Material and Methods: We retrospectively reviewed blood bank records of all SCD patients that were transfused pRBCs since 1990 to date. Statistical analysis was performed using the Chi square test and Fischer’s exact test. Results: See table 1. Table I: General data of various patient groups Major patient groups Total pt # (%) Sex (m/f) Pt age in yrs, Median (range) Total pRBC units Median Tn #/pt(range) 121 (31.3%, 56m, 65f) developed alloantibodies (alloABs). Grand total of all patients 500 240/260 22 (0.7–79) 16617 14 (1–524) CEK (& ABO) matched tn pts 113 62/51 8 (0.5–35) 2354 10 (1–143) Regular (ABORh) matched Tn pts 387 (100) 178/209 26 (0.7–79) 14263 18 (1–524) AlloAB forming patients 121 (31.3) 56/65 29 (5–70) 7338 26 (1–500) Non-alloAB forming pts 266 (68.7) 122/144 25 (0.7–79) 6925 12 (1–524) Table II: Transfusion characteristics of patients forming alloantibodies Data on pts forming alloantibodies CEK matched patients CEK unmatched pRBC Transfusion (Tn) patients(387) >0 ABs >1 ABs >2 ABs >3 ABs >4 ABs Number of patients 6/113 121/387(31%) 57/121 (47%) 29/57 (51%) 16/29 (55%) 11/29 # of Transfusions before AB formation 9.5 (0–106) 7 (0–270) 2 (0–106) 0 (0–89) 0 (0–180) 0 (0–16) # of pts with > 5 Tn before alloAB formed 4/6(67%) 68/121(56%) 21/57(37%) 5/29(17%) 4/16(25%) 1/11(9%) # of pts with >30 Tn before AB formed 1 12 4 2 1 0 There were 33 patients with anti-C, 74 with anti-E, and 57 with anti-K ABs (a total of 164, incidence of 2.235 CEK alloABs/100 transfusions{Tn}). 266 patients (6925 Tn, 68%) did not develop any alloABs. 21 patients developed multiple alloABs simultaneously after a single transfusion. pRBC Tn was 1½ times more likely to lead to alloAB formation in adult females (p=0.006) and children (p=0.011) over adult males. >13% patients transfused with CEK unmatched units developed ABs to C, E, K and other antigens. 2/3 patients never developed ABs. Once allosensitized, there was an sustained ↑ chance of developing a 2nd (& later) AB (50% Vs 31% for first timers) with fewer Tn (usually <5). A small number of patients developed alloABs later (>30 pRBCs). Patients receiving CEK matched pRBCs developed non-CEK ABs at 2½ times lower frequency than the corresponding group of patients. It was found that the technologist required 30 more minutes and $153 extra in reagent costs for this extended CEK match. Most Rh negative pRBC units were also CEKneg. 90% of our donors are Caucasian. Conclusions: This study showed that utilizing CEK negative pRBCs dramatically ↓ alloAB(p<0.01) formation in our SCD patients, including C, E, and K and other minor blood group antigens. Patients transfused without C, E, K antigen match developed ABs to C, E, K, and other antigens. In some patients, allosensitization possibly activates the immune system into a hyperactive state leading to further, earlier, multiple and simultaneous alloAB and autoAB formation. Though unlikely, Rh negative and CEKneg pRBCs may also be negative for other minor antigens. Extended antigen matching made it easier to find proper blood units due to less formation of alloABs. However, it resulted in overuse of Rh negative pRBCs and effort to find CEKneg pRBCs for every transfusion.

Donor Availability for Extended Phenotype Matching for Transfusion in Thalassemia and Sickle Cell Disease.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2287-2287 ◽  
Author(s):  
Connie M Westhoff ◽  
Marek Simm ◽  
Carl Myers ◽  
Stella T Chou ◽  
Adonis Stassinopoulos ◽  
...  
Keyword(s):  
African American ◽  
Sickle Cell Disease ◽  
Inventory Management ◽  
Sickle Cell ◽  
High Throughput ◽  
Large Scale ◽  
Blood Group Antigens ◽  
Cell Disease ◽  
Donor Pool ◽  
Donor Recruitment

Abstract Abstract 2287 High throughput genomic testing for blood groups allows large scale antigen typing and assessment of donor pool compatibility with chronic transfusion dependent populations, particularly thalassemia or sickle cell disease (SCD) patients, in order to decrease RBC alloimmunization. Thus, it is crucial to determine if the quantity and antigen diversity of the donor pool meets the demands to sustain these patients on phenotype/genotype extended matched chronic transfusion protocols. We calculated the most common extended RBC predicted phenotypes for the 12 major clinically significant blood group antigens, D, CcEe, K, Jka/b, Fya/b, and Ss, in patients undergoing chronic transfusion for sickle cell disease (n=203) or thalassemia (n=98). The most common phenotypes in each diagnostic group were used to determine the prevalence of these phenotypes in a single day donor inventory (n=5,000) and stratified by ethnic group (70% Caucasian, 10% African-American, 13% Hispanic, 5% Asian, and 2% Other). All patient samples were tested for the presence of the GATA mutation which disrupts erythroid expression of Fy(b), and if present deemed not at risk for Fy(b) alloimmunization. The majority of patients with SCD and thalassemia are RhD positive (97% and 90% respectively), but differ in extended Rh phenotype, with Ro (Dce) prevalent in SCD pa tients (61%), and R1 (DCe) in thalassemia patients (79%). For patients with SCD, the most prevalent antigen-negative phenotypes were 17% C-E-K-,Fy(a-),Jk(b-), S-; 9% C-E-K-, Fy(a-),S-; 5% E-K-,Fy(a-),S-; and 4% C-K-,Fy(a-), Jk(b-), S-. In patients with thalassemia, no minor antigen profile exceeded 5% of individuals. The most prevalent antigen-negative profiles were 5% E-c-K-, Fy(b-),Jk(b-),S-, and 4% E-K-. Comparison of the most prevalent antigen-negative phenotype in patients with SCD with the donors revealed only 0.06% Caucasian (n=2), but 20% of the African-American donors (n=90) were antigen-negative matches. For the second most prevalent phenotype, 0.08% Caucasian (n=3) and 33% of African-American (n=167), 2% of Hispanic (n=13), and 5% other (n=5) were antigen-negative matches. For the third and fourth prevalent phenotypes, 47% of African-American (n=233) and 23% (n=115) respectively, were antigen-negative matches, while only 0.14% (n=5) and 0.06% (n=2) of Caucasians, but 5% (n=31) and 2% (n=13) of Hispanic donors were appropriate matches, respectively. For the thalassemia patients, antigen matches for the most common phenotype were found most often in Asian (13%) and donors identifying as “other” (6%). Matches were present in only 2% of the Caucasians, 2% of Hispanics, and 1.8% of African-American donors for thalassemia patients. These results confirmed the importance and impact of African-American donors for extended antigen-matching for patients with SCD. Less than 1% of our Caucasian donors could serve as extended matching for SCD. Nearly 20% of patients with SCD are negative for a common group of antigens, which allows future donor recruitment efforts focused on extended antigen profiles of the donor. Patients with thalassemia do not have a common antigen-negative profile, but extended matching for these patients can be improved by increase recruitment of Asian donors. High throughput genotyping enables typing of large numbers of donors, and potentially the majority of the donor inventory. Analysis of antigen-negative phenotypes in the donor pool with analysis of patient groups is important for inventory management, focused donor recruitment, and improved transfusion practice by avoiding alloimmunization. Disclosures: Stassinopoulos: Cerus: Employment, Equity Ownership, Patents & Royalties.

scholarly journals Characterization and statistical modeling of glycosylation changes in sickle cell disease

2021 ◽  
Vol 5 (5) ◽  
pp. 1463-1473
Author(s):  
Heather E. Ashwood ◽  
Christopher Ashwood ◽  
Anna P. Schmidt ◽  
Rebekah L. Gundry ◽  
Karin M. Hoffmeister ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Sickle Cell Disease ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Blood Group ◽  
Sickle Cell ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Blood Group Antigens ◽  
Cell Disease

AbstractSickle cell disease is an inherited genetic disorder that causes anemia, pain crises, organ infarction, and infections in 13 million people worldwide. Previous studies have revealed changes in sialic acid levels associated with red blood cell sickling and showed that stressed red blood cells bare surface-exposed clustered terminal mannose structures mediating hemolysis, but detailed glycan structures and anti-glycan antibodies in sickle cell disease remain understudied. Here, we compiled results obtained through lectin arrays, glycan arrays, and mass spectrometry to interrogate red blood cell glycoproteins and glycan-binding proteins found in the plasma of healthy individuals and patients with sickle cell disease and sickle cell trait. Lectin arrays and mass spectrometry revealed an increase in α2,6 sialylation and a decrease in α2,3 sialylation and blood group antigens displayed on red blood cells. Increased binding of proteins to immunogenic asialo and sialyl core 1, Lewis A, and Lewis Y structures was observed in plasma from patients with sickle cell disease, suggesting a heightened anti-glycan immune response. Data modeling affirmed glycan expression and plasma protein binding changes in sickle cell disease but additionally revealed further changes in ABO blood group expression. Our data provide detailed insights into glycan changes associated with sickle cell disease and refer glycans as potential therapeutic targets.

scholarly journals RH genotyping in a sickle cell disease patient contributing to hematopoietic stem cell transplantation donor selection and management

Blood ◽  
2010 ◽  
Vol 116 (15) ◽  
pp. 2836-2838 ◽  
Author(s):  
Ross M. Fasano ◽  
Alessandro Monaco ◽  
Emily Riehm Meier ◽  
Philippe Pary ◽  
A. Hallie Lee-Stroka ◽  
...  
Keyword(s):  
Stem Cell ◽  
Sickle Cell Disease ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Blood Group ◽  
Sickle Cell ◽  
Disease Patient ◽  
Nucleotide Sequencing ◽  
Cell Disease ◽  
Hematopoietic Stem

Abstract African individuals harbor molecular RH variants, which permit alloantibody formation to high-prevalence Rh antigens after transfusions. Genotyping identifies such RH variants, which are often missed by serologic blood group typing. Comprehensive molecular blood group analysis using 3 genotyping platforms, nucleotide sequencing, and serologic evaluation was performed on a 7-year-old African male with sickle cell disease who developed an “e-like” antibody shortly after initiating monthly red blood cell (RBC) transfusions for silent stroke. Genotyping of the RH variant predicted a severe shortage of compatible RBCs for long-term transfusion support, which contributed to the decision for hematopoetic stem cell transplantation. RH genotyping confirmed the RH variant in the human leukocyte antigen–matched sibling donor. The patient's (C)ces type 1 haplotype occurs in up to 11% of African American sickle cell disease patients; however, haplotype-matched RBCs were serologically incompatible. This case documents that blood unit selection should be based on genotype rather than one matching haplotype.

RH Gene Polymorphisms Are Risk Factor for Alloimmunization in Patients with Sickle Cell Disease.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 455-455 ◽  
Author(s):  
Connie M. Westhoff ◽  
Sunitha Vege
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Cost Effective ◽  
Blood Group Antigens ◽  
Cell Disease ◽  
Negative Effects ◽  
Transfusion Therapy ◽  
Risk Patients ◽  
Patient Groups ◽  
Red Cell Transfusion

Abstract Transfusion therapy for treatment of sickle cell disease (SCD) is predicted to increase, following the significant benefit of chronic red cell transfusion demonstrated by the stroke prevention trial (STOP). Despite progress in mitigating negative effects of transfusion therapy with the use of iron chelating agents, alloimmunization remains a significant problem. Patients with SCD have a higher incidence of antibody production compared to other patient groups undergoing chronic transfusion. To limit alloimmunization, many programs transfuse SCD patients with RBCs that are phenotype-matched for the most immunogenic blood groups, Rh and K, and some programs also supply RBCs from African-American (AA) donors. Although this approach reduces the incidence of alloantibody production, it is resource- and cost-prohibitive for many programs, and, importantly, some patients (∼5%) still become alloimmunized. The development of high-throughput genotyping for blood group antigens will make antigen-matching cost effective; therefore, it is important to determine why some patients become alloimmunized despite antigen-matching. We investigated the antibody specificity and sequenced the RH genes in 46 SCD patients who were alloimmunized, despite having received Rh and K matched units. The antibodies identified included anti-D, or -C, or -e, and/or antibodies to high-prevalence antigens. None had anti-E. RH gene sequencing revealed that 20 patients had a RHD-CE(3–7)-D hybrid gene in which RHD exons 3 through 7 are replaced with reciprocal exons from RHCE. The resulting Rh protein encodes an altered C antigen. This D-CE-D gene was also linked to an RHce allele encoding altered e antigen. These patients had anti-C and/or anti-e in their serum (i.e.-hrB). We screened healthy AA donors and found that the prevalence of the hybrid RHD-CE(3–7)-D gene in this population is 5–8%. The remaining 26 patients were homozygous for mutations in RHce and had produced anti-e, and some also had mutations in RHD and had produced anti-D. These results suggest that inheritance of a RHD-CE-D gene or altered RHce, with or without altered RHD, underlies Rh alloimmunization in SCD. The altered Rh proteins are not distinguished with current serologic typing reagents. Therefore, these patients are not truly Rh antigen matched. The development of RH genotyping platforms offers a potential solution to prevent alloimmunization by identifying SCD patients who are homozygous for variant alleles and at risk for production of alloantibodies to Rh antigens. The 5–8% of donor units with the same RH genotype could be directed to these high risk patients.

Prevalence of Thrombophilia In Patients with Sickle Cell Disease and Osteonecrosis

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3184-3184
Author(s):  
Murtadha K. Al-Khabori ◽  
Anil Pathare ◽  
Khalil Al Farsi ◽  
Mohammed Al Huneini ◽  
Salam Alkindi
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Protein C ◽  
Dna Analysis ◽  
White Cell Count ◽  
Protein S ◽  
Cell Disease ◽  
High Prevalence ◽  
Low Levels

Abstract Abstract 3184 Background: Osteonecrosis (ON) of the femoral and humeral heads is frequently seen in patients with sickle cell disease (SCD). Earlier studies reported a high prevalence of thrombophilia in patients with ON. Aims: To study the prevalence of thrombophilia in patients of SCD with ON. Methods: Case records of SCD patients with ON were retrospectively reviewed for protein S, protein C, and anti-thrombin deficiency, along with activated protein C resistance (APCR). Results: A total of sixty-three patients were identified, 35 of whom were males, with a median age of 21 years (range 15to 46). Median haemoglobin, total white cell count and platelet counts were 10 g/dL (range 7.7to 13.3), 7.5 ×109/L (range 3.4 to 16.7) and 302 ×109/L (range 72 to 1101) respectively. Twenty-eight patients were on hydroxyurea. Thrombophilia testing showed that 29% (95% confidence interval: 17–40), 47% (95% CI: 29–64) and 79% (95% CI: 65–93) of the patients had low levels of functional (<60 unit/dl), total antigenic (<70 unit/dl) and free antigenic (<70 unit/dl) protein S respectively, while 21% (95% CI: 10–31) and 67% (95% CI: 46–87) had low levels of functional (<70 unit/dl) and antigenic (<70 unit/dl) protein C respectively. In addition, 14% (95% CI: 5–23) and 22% (95% CI: 0–56) of the patients had low levels of functional (<80 unit/dl) and antigenic (<80 unit/dl) anti-thrombin levels respectively. Only 2% (95% CI: 0–5) of these patients had an abnormally low APCR (APCR ratio ≤2.3). Summary/Conclusions: Patients with SCD and ON have a high prevalence of thrombophilia. These results indicate that a prospective study with more detailed thrombophilia work-up, along with confirmatory DNA analysis, as well as a study of the role of prophylactic anticoagulation in such patients is highly warranted. Disclosures: Pathare: Sultan Qaboos University: Employment, Research Funding. Alkindi:Sultan Qaboos University: Employment, Research Funding.

Sickle Cell Trait: A Benign State?

2016 ◽  
Vol 136 (3) ◽  
pp. 147-151 ◽  
Author(s):  
Taiwo R. Kotila
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Dna Analysis ◽  
Sickle Cell Trait ◽  
Beta Thalassemia ◽  
Compound Heterozygous ◽  
Cell Disease ◽  
Benign Condition ◽  
Red Cell Indices ◽  
Heterozygous Form

Background: Sickle cell trait (SCT) is the heterozygous form of sickle cell disease and expectedly should be a benign state with no complications ascribed to it. There are numerous reports challenging its being a benign condition, though this is controversial. Methods and Results: A review of the results of the accompanying investigations done on some of the patients show that beta thalassemia may be responsible for many of the ascribed symptoms and complications. These patients may therefore have sickle cell beta thalassemia, a compound heterozygous form of sickle cell disease. Conclusion: It is important to screen for beta thalassemia using red cell indices and quantitation of the different hemoglobin fractions before attributing any symptoms to SCT. DNA analysis, though useful in ascertaining the presence of the sickle cell gene, is not sufficient. There is the need to exclude the presence of mutations for beta thalassemia, which often is geographical region-specific.

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