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.

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 Molecular Screening of Hemoglobin S Variant in Anemia Patients of Eastern UP Population

2019 ◽  
Author(s):  
Vandana Rai ◽  
Upendra Yadav ◽  
Pradeep Kumar
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Inherited Disease ◽  
Cell Disease ◽  
Major Health Problem ◽  
Major Health ◽  
Hemoglobin S ◽  
Pcr Rflp ◽  
Clinically Significant ◽  
Β Chain

AbstractHemoglobinopathies are the most common type of inherited disease in human. in India the most frequent and clinically significant hemoglobin structural variants are HbS, HbD and HbE. The HbS mutation, in which a glutamic acid at position 6 in the β chain is substituted for valine Sickle cell disease is a major health problem in some parts of India. 2 ml blood sample was collected from 350 anemia patient and PCR-RFLP method was used for hemoglobin S analysis. Out of 350 samples, in four individuals, HbS mutation was found in homozygous (β 6/β 6) condition. All four individuals are Sickle cell cases. In conclusion, the percentage of Sickle cell disease was observed as 1.14% in Eastern UP anemic patients.

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.

Lead Neuropathy and Sickle Cell Disease

PEDIATRICS ◽  
1974 ◽  
Vol 54 (4) ◽  
pp. 438-441
Author(s):  
Gerald Erenberg ◽  
Steven S. Rinsler ◽  
Bernard G. Fish
Keyword(s):  
Case Report ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Lead Poisoning ◽  
Cell Disease ◽  
Hemoglobin S ◽  
Increased Risk ◽  
Rare Manifestation ◽  
Poisoning In Children

Four cases of lead neuropathy in children with hemoglobin S-S or S-C disease are reported. Neuropathy is a rare manifestation of lead poisoning in children, and only ten other cases have been well documented in the pediatric literature. The last previous case report of lead neuropathy was also in a child with hemoglobin S-S disease. The neuropathy seen in the children with sickle cell disease was clinically similar to that seen in the previously reported cases in nonsicklers, but differed in both groups from that usually seen in adult cases. It is, therefore, postulated that children with sickle cell disease have an increased risk of developing neuropathy with exposure to lead. The exact mechanism for this association remains unknown, but in children with sickle cell disease presenting with symptoms or signs of peripheral weakness, the possibility of lead poisoning must be considered.

scholarly journals Sickle Retinopathy in a Person with Hemoglobin S/New York Disease

2012 ◽  
Vol 2012 ◽  
pp. 1-3 ◽  
Author(s):  
Donovan Calder ◽  
Maryse Etienne-Julan ◽  
Marc Romana ◽  
Naomi Watkins ◽  
Jennifer M. Knight-Madden
Keyword(s):  
New York ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Sickle Cell Trait ◽  
Laboratory Diagnosis ◽  
Compound Heterozygote ◽  
Cell Disease ◽  
Hemoglobin S

A patient who presented with sickle retinopathy and hemoglobin electrophoresis results compatible with sickle cell trait was found, on further investigation, to be a compound heterozygote with hemoglobin S and hemoglobin New York disease. This recently reported form of sickle cell disease was not previously known to cause retinopathy and surprisingly was observed in a non-Asian individual. The ophthalmological findings, the laboratory diagnosis, and possible pathophysiology of this disorder are discussed. Persons diagnosed with sickle cell trait who present with symptoms of sickle cell disease may benefit from specific screening for this variant.

scholarly journals Case Report: Acute Stroke in Young Adult Patient with Moyamoya Syndrome Secondary to Sickle Cell Disease

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 13-13
Author(s):  
Oladipo Cole ◽  
Asia Filatov ◽  
Javed Khanni ◽  
Patricio Espinosa
Keyword(s):  
Case Report ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Moyamoya Disease ◽  
Conflicts Of Interest ◽  
Acute Chest Syndrome ◽  
African American Female ◽  
Moyamoya Syndrome ◽  
Cell Disease ◽  
Radiographic Findings

Moyamoya disease, well described in literature, is a chronic cerebrovascular occlusive disorder. It is characterized by progressive stenosis/occlusion of the terminal portions of the internal carotid arteries (ICA) and the proximal portions of the middle cerebral arteries (MCA). Less frequently described is Moyamoya syndrome, the name given to radiographic findings consistent with Moyamoya disease, but with an identifiable cause. The diseases associated with Moyamoya Syndrome include Sickle Cell Disease (SCD), Thalassemias, and Down's Syndrome to name a few. Common complications of Moyamoya include both ischemic and hemorrhagic strokes. Upon literature review, Moyamoya syndrome caused by SCD is not well described. When it is, the discussion is centered around the pediatric patient population and surgical management. Our case report describes a 22-year-old African American female with SCD who initially presented with Acute Chest Syndrome. Her hospital course was complicated by development of overt debilitating neurologic deficits. Subsequently, she was found to have Moyamoya Syndrome on neuroimaging. She was successfully treated with medical management without any surgical intervention. This case highlights the necessity of thorough examination, differential diagnosis, imaging findings, and consideration of predisposing syndromes in the work-up for Moyamoya syndrome; especially individuals with Sickle Cell Disease. Disclosures No relevant conflicts of interest to declare.

scholarly journals Utility of Procalcitonin in Differentiating Acute Chest Syndrome from Vaso-Occlusive Crisis in Sickle Cell Disease

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 10-11
Author(s):  
Satish Maharaj ◽  
Simone Chang ◽  
Karan Seegobin ◽  
Marwan Shaikh ◽  
Kamila I. Cisak
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Complete Blood Count ◽  
Conflicts Of Interest ◽  
Statistical Significance ◽  
Acute Chest Syndrome ◽  
Adult Males ◽  
Cell Disease ◽  
Unequal Variances ◽  
Recorded Data

Background: Acute chest syndrome (ACS) frequently complicates sickle cell disease (SCD) and is a leading cause of hospitalization and mortality. Many factors have been implicated in ACS, including infections, thrombosis, fat and pulmonary emboli. However, a clear etiology is not defined in 50% of the cases and ACS is considered a clinical endpoint for different pathogenic processes (Vichinsky et al 2000). The non-specific nature of ACS makes diagnostic tests challenging, and there are no serum tests clinical used to aid diagnosis. Procalcitonin (PCT) is a prohormone of calcitonin and serum PCT rises within hours of an inflammatory stimulus. PCT has clinical utility as a marker of severe systemic inflammation, infection, and sepsis (Becker et al. 2008). Few studies have evaluated PCT as a biomarker for ACS in patients presenting with vaso-occlusive crises (VOC). Two studies have reported no difference in PCT (Biemond et al. 2018 and Stankovic et al 2011), while one study reported higher PCT between ACS and VOC (Patel et al 2014). Methods: We retrospectively reviewed 106 patients with SCD who presented to the emergency department with fever and painful crises during 2015-2019. The patients were divided into two categories based on discharge diagnoses - patients with VOC only (n=88) and patients with ACS (n=18). Inclusion criteria for both groups were patients with SCD, 17 years and older and PCT measurement on presentation. Exclusion criteria were defined as patients who had received empiric antibiotics prior to PCT testing. Data collected on presentation included genotype, age, gender, complete blood count, PCT, creatinine, total bilirubin and hydroxyurea use. Length of stay was recorded. Data was analyzed between the two groups using descriptive statistics and accounting for unequal variances, withp-value set at 0.05 for significance. Results: Demographics and clinical characteristics are summarized in Table 1 (Figure). The sample included primarily adult males (77%), with about two-thirds on hydroxyurea. Genotype HbSS (73.6%) was most prevalent followed by HbSC (22.6%) and HbSβ (3.8%). The ACS group had a higher percentage of HbSS, lower use of hydroxyurea and higher mean bilirubin. Mean PCT for the ACS group was 0.52 ng/mL (range, 0.05-2.04), compared to 0.31 ng/mL (range, 0.02-6.82) in the VOC group; withp=0.084. ROC analysis showed a PCT&gt;0.5ng/mL had 39% sensitivity and 85% specificity for ACS in this sample. Conclusion: In this sample, PCT on presentation was higher in those with ACS compared to VOC, but this difference did not achieve statistical significance. Further study in a larger population would be useful to evaluate this finding. Disclosures No relevant conflicts of interest to declare.

scholarly journals Interferon Induction By HbS, SERINC5 Upregulation and Reduction of HIV-1 Nef and AP2 Contribute to HIV-1 Restriction in Sickle Cell Disease

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 5-6
Author(s):  
Namita Kumari ◽  
Marina Jerebtsova ◽  
Songping Wang ◽  
Sharmin Diaz ◽  
Sergei Nekhai
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Interferon Response ◽  
Cell Disease ◽  
Restriction Factors ◽  
Peripheral Blood Mononuclear ◽  
Hiv 1

Concerted action of numerous positively acting cellular factors is essential for Human immunodeficiency virus type 1 (HIV-1) replication but in turn is challenged by anti-viral restriction factors. Previously we showed that ex vivo one round HIV-1 replication and replication of fully competent T-tropic HIV-1(IIIB) is significantly reduced in peripheral blood mononuclear cells (PBMCs) obtained from patients with Sickle Cell Disease (SCD). Further, we identified and confirmed CDKN1A (p21) and CH25H as host restriction factors expressed in SCD PBMCs that may contribute to the HIV-1 inhibition, in addition to the previously reported SAMHD1 and IKBα. Since CH25H is an interferon stimulated gene (ISG), we analyzed IRFs and interferon expression in SCD PBMCs. Higher levels of IRF7 and IFNβ mRNA were observed in SCD PBMCs compared to controls. We probed further to ascertain if hemin or sickle Hb was responsible for interferon response. We found upregulation of IFNβ in THP-1 - derived macrophages treated with lysates of HbSS RBCs or purified HbS as compared to untreated or HbA treated controls. HbSS RBCs lysates and purified HbS inhibited HIV-1 gag mRNA expression in monocyte-derived macrophages infected with HIV-1(Ba-L). Recent clinical study showed increased levels of CD4 in HIV-1 infected SCD patients in Africa. Thus we analyzed CD4 levels in HIV-1 IIIB infected SCD PBMCs, and found them to be higher compared to controls. Levels of HIV-1 nef mRNA, that controls CD4 expression was lower in HIV-1 IIIB infected SCD PBMCs. As Nef counteracts SERINC3/5 restriction factor, we analyzed its expression as well as the expression of AP2 clathrin adaptor that is required for Nef mediated internalization of CD4. AP2 expression was lower and SERINC5 expression was higher in SCD PBMCs. CONCLUSIONS: SCD PBMCs could resist HIV-1 infection because of the increased IFNβ production by macrophages exposed to HbSS or sickle cell RBCs. SCD PBMC have increased levels of SERNIC5 and lower levels of HIV-1 Nef and host AP2 expression that, culumlatively, can increased CD4 levels and lead to the overall improved immunological health of SCD patients. ACKNOWLEDGMENTS: This work was supported by NIH Research Grants (1P50HL118006, 1R01HL125005, 1SC1HL150685, 5U54MD007597, 1UM1AI26617 and P30AI087714). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Disclosures No relevant conflicts of interest to declare.

WHY DO SICKLE SCREENING IN CHILDREN?

PEDIATRICS ◽  
1973 ◽  
Vol 51 (4) ◽  
pp. 742-745
Author(s):  
Norman Fost ◽  
Michael M. Kaback
Keyword(s):  
Genetic Counseling ◽  
Sickle Cell Disease ◽  
Clinical Significance ◽  
Sickle Cell ◽  
Early Identification ◽  
Cell Disease ◽  
Pilot Studies ◽  
Population Groups ◽  
Screening Programs

An approximate desire to "do something" about sickle cell disease has produced a plethora of sickle screening programs. While the advantages of early identification of individuals with sickle cell disease is apparent, the purpose of identifying children with sickle trait is less clear. There is uncertainty about the clinical significance of sickle trait, and there are ethical and legal hazards in being so identified. The demonstrated failure of genetic counseling to successfully transmit information in other population groups also dictates a reexamination of the presumed benefits of sickle screening programs. Screening programs should be initiated after pilot studies have resolved these issues, not before.

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