scholarly journals A Novel Next-Generation Sequencing Based Assay for Non-Invasive Prenatal Testing of Sickle Cell Disease without Paternal DNA

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2369-2369
Author(s):  
Nelda Itzep ◽  
Celeste K Kanne ◽  
David Tsao ◽  
Oguzhan Atay ◽  
Vivien A Sheehan
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Prenatal Testing ◽  
Maternal Blood ◽  
Beta Thalassemia ◽  
Cell Disease ◽  
Advisory Committees ◽  
Non Invasive ◽  
The Us ◽  
Allele Fraction

Abstract Introduction: Over 300,000 infants are born with sickle cell disease (SCD) every year worldwide, including at least 1,000 in the US. Prenatal diagnosis by amniocentesis or chorionic villus sampling is available; but high cost, invasiveness, and risk of miscarriage limit their use. Recently, non-invasive prenatal testing (NIPT) has become commonplace for aneuploidies, including Trisomy 21. These non-invasive tests operate by genetic analysis of the cell-free fetal DNA (cffDNA) present in maternal blood. The safety and accuracy of NIPT have been key drivers for its rapid and widespread adoption. Yet, no NIPT for SCD or other hemoglobinopathies have been commercialized to date, despite the large numbers of patients affected in the US and worldwide. While de novo mutations can only be of fetal origin and can be identified by available next-generation sequencing (NGS) methods, NIPT for recessively inherited disorders is more challenging. This is because a mother who is a carrier for a recessive disorder contributes a high level of background pathogenic DNA molecules. Therefore, a key technical challenge of NIPT for recessive disorders is developing an assay sensitive enough to detect <5% deviation from 50% allele fraction. To overcome this challenge, we have developed and optimized an NIPT for SCD by assessing the relative mutation dosage of fetal SCD and beta-thalassemia DNA through a novel molecular counting strategy using NGS. Objectives: The primary objective of this study is to evaluate the performance of a novel NIPT for sickle cell disease. Methods: The SCD NIPT assay and associated custom bioinformatics analysis were performed on cfDNA obtained from a training cohort of non-pregnant compound heterozygotes for SCD. The SCD NIPT assay was then performed on a validation cohort of pregnant women with either SCD or sickle cell trait (SCT). The accuracy of the SCD NIPT was evaluated by comparison with newborn screening results. Results: Non-pregnant individuals with genotype HbSE, HbSC, or HbS/beta-thalassemia were included as a training cohort to establish the precision and accuracy of the assay for measuring HbS allele fraction from cfDNA. As expected, the HbS allele fraction in these individuals was 0.500 (standard deviation = 0.011, n = 26), and there was no detectable fetal fraction in these samples. Both training and validation cohort results matched the theoretical limit of detection set by the number of cell-free HBB DNA molecules in plasma. The precision and accuracy of the HBB assay on cfDNA were then used in conjunction with >1000 pre-clinical samples (mixtures of sheared SCT and SCD genomic DNA) to determine analytical sensitivity >98% and specificity >99%, even in the absence of paternal DNA. Conclusion: We have developed an assay for non-invasive prenatal testing of sickle cell disease. The results obtained to date indicate that the assay reliably detects fetal SCD when the fetal fraction is as low as 5%, the same limit as aneuploidy NIPT. A fetus with SCD has already been identified, and follow-up is ongoing with >20 pregnancies. Since the HBB NIPT is highly targeted, sequencing cost is <$30 per sample. The ability to ascertain fetal SCD status based only on maternal blood will be valuable in clinical settings where the father is unavailable or sample collection would be inconvenient or time-consuming. Several Phase I/II and Phase III trials for curing SCD or beta-thalassemia using autologous gene-editing of stem cells are currently in progress. SCD NIPT could be particularly useful for deciding to bank umbilical cord blood as a source of stem cells for future gene-editing cures. Disclosures Tsao: BillionToOne: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties. Atay:BillionToOne: Employment, Equity Ownership, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties.

Non-invasive prenatal diagnosis of beta-thalassemia and sickle-cell disease using pyrophosphorolysis-activated polymerization and melting curve analysis

2012 ◽  
Vol 32 (6) ◽  
pp. 578-587 ◽  
Author(s):  
Marion Phylipsen ◽  
Supawadee Yamsri ◽  
Emmely E. Treffers ◽  
Diahann T. S. L. Jansen ◽  
Warsha A. Kanhai ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Melting Curve ◽  
Curve Analysis ◽  
Beta Thalassemia ◽  
Melting Curve Analysis ◽  
Cell Disease ◽  
Non Invasive

scholarly journals Interest of a New Method for Free Plasma Heme Related Species Dosages in Sickle Cell Disease and Beta Thalassemia

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3381-3381
Author(s):  
Laurent Kiger ◽  
Sandia Adypagavane ◽  
Laura Bencheikh ◽  
Nicolas Hebert ◽  
Stephane Moutereau ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Healthy Volunteers ◽  
Board Of Directors ◽  
Sickle Cell ◽  
Categorical Variables ◽  
Beta Thalassemia ◽  
Plasma Samples ◽  
Cell Disease ◽  
Advisory Committees ◽  
Spearman Test

Introduction: Hemolytic anemia combines 3 components to various extents: extravascular hemolysis, intravascular hemolysis and dyserythropoiesis. Global hemolysis in excess to defense lines induces oxidative and inflammatory syndromes and vascular damages in various organs. Therefore, accurate hemolysis biomarkers are required for a better evaluation of hemolytic disorders, such as sickle cell disease (SCD) or thalassemia syndromes and to evaluate the efficacy of various therapies. Accordingly, we have developed a new spectrophotometric method to measure and calculate several hemolysis biomarkers in plasma or serum including Hemoglobin in various forms (HbO2, HbCO, MetHb), Heme or Hemin bound to albumin or to hemopexin, total bilirubin and total hemopexin. Patients and Method : Blood samples were collected at steady-state for 77 SCD adults (mean age 39.8 ± 10.2 yrs, M/F ratio 0.64) and 23 beta thalassemia patients (mean age 42.7 ± 16 yrs, M/F ratio 0.91); SCD patients (SS or Sb0-Thalassemia) were either treated with Hydroxycarbamide (HU: 27) or not (NT: 50). For comparison, plasma samples from healthy volunteers (HV) were also analyzed. Continuous variables were expressed as means ± SD or medians [interquartile range], depending on their normal or asymmetric distributions. Categorical variables were expressed as numbers (%). Univariate analyses were done using Student's t-test or Mann-Whitney non-parametric test, depending on the distribution. Correlation were analyzed using a spearman test. The dosage methodology is based on the light absorption spectrophotometry of plasma samples using an appropriate mathematical conversion of the signal, reference spectra of the different species and some chemical modifications of the iron redox and ligation states. Results: The levels of plasma Hb were statistically higher in homozygous SCD patients compared to beta-thalassemia patients (p=0.001) and healthy volunteers, with median of 6.3 [3.4-11], 2.6 [1-5.4] and 1.7 [0.5-3] µM respectively (Table 1). Interestingly levels of plasma heme were higher in beta thalassemia patient compared to SCD patients (p=0.0001) and HV, with a mean of 1.05 [0.05-3], 10.5 [3.5-24] and ≤ 0.2 µM level of detection respectively (Table 1). A significant negative correlation was found between heme and hemopexin levels in both diseases (p<0.0001; r=0.85). Among 77 SS or Sb0-Thalassemia patients, 29 were treated by HU without any difference for plasma Hb, plasma Heme and Hemopexin values compared to non-treated patients. Discussion and Conclusions: plasma Hb is a more accurate dosage for intra vascular hemolysis than other biomarkers which are not specific of intra vascular hemolysis and could be biased by other pathological conditions: LDH or ASAT can be increased in hepatic or muscular cytolysis, bilirubin is dependent on the heme oxygenase and glycuronyl transferase activities, and reticulocytes are dependent on erythropoiesis. Our results showed that the intra-vascular hemolysis is more pronounced in SCD compared to beta-thalassemia based on the plasma Hb levels. The elevated plasma heme concentration in beta thalassemia is a new finding that should be investigated in more details. It could reflect the ineffective erythropoiesis or heme export from erythroblasts or macrophages involving hemopexin scavenging. Disclosures Bencheikh: Hemanext: Research Funding. Bartolucci:HEMANEXT: Membership on an entity's Board of Directors or advisory committees; AddMedica: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Novartis: Membership on an entity's Board of Directors or advisory committees.

scholarly journals Clinical validity of single-gene non-invasive prenatal testing for sickle cell disease and beta thalassemia

2021 ◽  
Author(s):  
Erik R. Westin ◽  
David S. Tsao ◽  
Oguzhan Atay ◽  
Brian P. Landry ◽  
Patrick P. Ye ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Newborn Screening ◽  
Cord Blood ◽  
Sickle Cell ◽  
Single Gene ◽  
Beta Thalassemia ◽  
Carrier Status ◽  
Cell Disease ◽  
Non Invasive ◽  
Prenatal Detection

AbstractBackgroundSickle cell disease (SCD) and beta thalassemia (β-thalassemia) are among the most common and severe genetically inherited disorders in the world. Although the maternal carrier status of these beta hemoglobinopathies is screened as a part of routine prenatal care in the US, the paternal carrier status is usually unavailable. Under this current screening paradigm, identification of the majority of SCD and beta thalassemia cases could therefore be delayed until newborn screening results are available. An effective reflex, non-invasive prenatal test (NIPT) that uses only maternal blood would permit prenatal detection of sickle cell disease and beta thalassemia by screening for these disorders without the need for paternal DNA. This screening would enable patients and healthcare providers to make informed decisions about diagnostic testing, and it could expand gene therapy treatment options by requesting cord blood banking at delivery. We have previously developed a single-gene NIPT platform (UNITY™) for SCD and beta thalassemia with extensive analytic validation and initial clinical validation in our prior studies.ObjectivesThe objective of this study is to further assess the clinical validity of single-gene NIPT for SCD and beta thalassemia in a larger pregnancy population.Study DesignPregnant women who screened positive for at least one allele of a beta hemoglobinopathy were enrolled at two academic medical centers for this retrospective cohort study. Single-gene NIPT for SCD and beta thalassemia was performed in blinded fashion on maternal blood samples to determine the fetal genotype and disease status. Single-gene NIPT findings were compared with either newborn screen results or genotyping of umbilical cord blood.ResultsSingle-gene NIPT detection of fetuses that are affected versus unaffected with SCD and beta thalassemia was 100% concordant with newborn screening follow-up data, even in challenging samples that contained a low fetal fraction (<5%) or at earlier gestational ages. Additionally, we obtained 98.5% concordance with newborn genotypes, including differentiating healthy fetal sickle cell carriers from homozygous healthy fetuses. The sensitivity of detecting fetal carrier status of beta hemoglobinopathies was 100% (90.8% to 100% CI), and the specificity was 96.4% (81.7% to 99.9 % CI).ConclusionsSingle-gene NIPT is a highly accurate screen for prenatal detection of SCD and beta thalassemia. The results further suggest that the maternal carrier screen with reflex single-gene NIPT workflow can significantly improve the detection rates of at-risk pregnancies from <50% to >98%.AJOG at a GlanceA.Why was this study conducted?Effective non-invasive prenatal testing (NIPT) is needed to permit safe in utero diagnosis of sickle cell disease (SCD) and beta thalassemia (β-thalassemia), and permit collection and banking of cord blood for future cell therapy. We have previously developed a single-gene NIPT method for SCD and β-thalassemia, with extensive analytic validation and initial clinical validation in our prior studies.B.What are the key findings?Our single-gene NIPT detection of SCD and β-thalassemia disease was 100% concordant with newborn screening follow-up data in 79 pregnancies at risk for beta hemoglobinopathies. Furthermore, a more stringent requirement, the detection of exact fetal genotype, was concordant in 67 out of 68 (98.5%) of pregnancies.C.What does this study add to what is already known?Our results validated that single-gene NIPT is an accurate and significantly improved screen for prenatal detection of SCD and β-thalassemia compared to current carrier screen workflow.

scholarly journals The Benefits Trial of PB-04 to Evaluate Safety, PK, and Preliminary Efficacy in Inducing Fetal Globin Expression in Beta Thalassemia Intermedia and Sickle Cell Disease

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 4159-4159
Author(s):  
Kevin H.M. Kuo ◽  
Sylvia Singer ◽  
Sujit Sheth ◽  
Hanny Al-Samkari ◽  
Gershwin Blyden ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Globin Gene ◽  
Beta Thalassemia ◽  
Beta Globin ◽  
Cell Disease ◽  
Advisory Committees ◽  
F Cells

Abstract Increased expression of fetal globin (HBG) has been shown to reduce clinical severity of beta-globin disorders and increase survival in sickle cell disease (SCD), through improved globin chain balance in beta thalassemia and reduced HbS polymerization. Pharmacologic approaches are considered most feasible for a majority of patients. Both proportions of F-cells and quantity of hemoglobin F (HbF)/cell are important for therapeutic effects. PB-04 was identified in a high-throughput screen of US and EU-approved drugs to activate HBG gene transcription, without cytotoxicity, to induce fetal globin expression (gamma globin mRNA, F-cells, HbF/cell, HbF), and to suppress or displace 4 repressors of the fetal globin gene promoter (BCL11A, LSD-1, KLF-1, and HDAC-3) in hemoglobinopathy patients' erythroid progenitors. PB-04 enhanced HbF in progenitors from hydroxyurea (HU)-treated patients with sickle cell disease. In in vivo studies, PB-04 induced fetal globin expression &gt;20-fold with oral dosing in anemic baboons, and by 3.5-fold in mice transgenic for 2 copies of the human β-globin gene locus. This agent has been approved and in broad use for Parkinson's Disease treatment for 5 decades in Europe and Canada, to enhance the PK of an active Parkinson's agent, solely in a combination formulation. Because of its safety with chronic dosing up to 1300 mg/day, PB-04 is therefore of interest for repurposing in the treatment of thalassemia and SCD. This Ph1b trial (NCT004432623) will evaluate safety, tolerability, PK, and preliminary efficacy (fetal globin expression) with at least 3 escalating dose cohorts in up to 24 beta thalassemia intermedia (BTI) patients and 12 patients with sickle cell disease, &gt; 18 years, both genders, with 12 weeks of treatment and 4 weeks of follow-up. Doses to be explored were selected from safe and active human equivalent doses in preclinical toxicology and efficacy studies in 2 species. Primary inclusion criteria include clinical diagnosis of BTI, including HbE beta thalassemia, with at least one beta globin gene mutation, or diagnosis of HbSS or HbSb thalassemia (after dose selection); total Hb levels 6-10 gm/dL. Exclusion criteria include red blood cell (RBC) transfusion within 2 months prior to administration of study medication, receiving regular transfusions, and hepatic or renal function &gt; 3 x institutional ULN. Primary endpoints include occurrence, severity, and duration of adverse events by CTCAE v5.0 criteria and PK parameters. Secondary endpoints include change from baseline in assays of HbF expression, total Hb, markers of hemolysis . Exploratory endpoints include select polymorphisms associated with basal fetal globin expression and in vitro responses to the study drug. Statistical analysis will assess the rate of adverse events, PK parameters by dose, and changes in F-cells, F-reticulocytes, HbF/cell, HbF (% and total), compared to 2 averaged baseline values using the Wilcoxon signed rank test. Changes will be analyzed by mixed effect models during the 12-week dosing and 4-week follow-up period. Currently 3 dose cohorts with BTI are enrolled. This study, if successful, will provide a rational basis for definitive trials of an established safe oral therapeutic, with no overlapping toxicities with other experimental or approved agents, for combined use with HU and other therapeutics which enhance red cell viability in the globin disorders. The expertise and contributions of Jim Cradock of NCATS TRND to this work before his passing are gratefully acknowledged. Disclosures Kuo: Agios: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bioverativ: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Apellis: Consultancy; Bluebird Bio: Consultancy; Pfizer: Consultancy, Research Funding; Novartis: Consultancy, Honoraria; Alexion: Consultancy, Honoraria. Sheth: CRISPR: Consultancy; Bluebird bio: Consultancy; Bristol Myers Squibb: Consultancy, Research Funding; Chiesi: Consultancy; Imara: Research Funding; Agios: Consultancy; Dispersol: Research Funding. Al-Samkari: Moderna: Consultancy; Amgen: Research Funding; Rigel: Consultancy; Argenx: Consultancy; Novartis: Consultancy; Dova/Sobi: Consultancy, Research Funding; Agios: Consultancy, Research Funding. Pace: Imara Inc.: Consultancy. Kuypers: Forma Therapeutics, Inc.: Research Funding. Nouraie: Phoenicia BioScience Inc.: Consultancy. Perrine: Agios Pharmaceuticals: Consultancy; Emmaus Medical: Consultancy.

scholarly journals Children in the United States with Sickle Cell Disease Experience Greater Educational Burden Than Those Living in Low/Middle Income and Other High-Income Countries

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3106-3106
Author(s):  
Fuad El Rassi ◽  
John James ◽  
Biree Andemariam ◽  
Beverley Francis-Gibson ◽  
Caterina P Minniti ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Board Of Directors ◽  
Sickle Cell ◽  
Research Funding ◽  
Cell Disease ◽  
Advisory Committees ◽  
Middle Income ◽  
Global Impact ◽  
The Us

Abstract Introduction: The Sickle Cell World Assessment Survey (SWAY) was a cross-sectional survey to assess the global impact and treatment of sickle cell disease (SCD). Complications of SCD can lead to significant negative effects on patient (pt) quality of life. Recurrent vaso-occlusive crises (VOCs) are one of the most common SCD complications and can lead to poor quality of life and chronic organ damage. SCD manifestations can start as early as the first year of life. The implications of SCD on a child's life can be far reaching and may affect education, the global impact of which has not been well described. Here, we assess data from SWAY to better understand the impact of SCD on education among pediatric pts in the US vs other high-income countries (HIC) and low/middle-income countries (LMIC). Methods: SWAY included individuals aged ≥6 years with a diagnosis of SCD. The survey was completed by proxy (parent/caregiver/guardian) for pts aged 6-11 years and could be optionally self-completed by pts aged ≥12 years. The survey consisted of 7 ratings-based (Likert scale) questions focused on education, where a score of 5, 6, or 7 indicated increasing levels of agreement. Pediatric pts were defined as those aged &lt;18 years. Per the World Bank definition, HIC were defined as having a gross national income per capita of ≥US$12,536; LMIC represented all remaining countries. SWAY was not designed to assess treatment outcomes; all analyses are descriptive. Age groups were not matched, and pts were not followed up over time. Results: Among the 769 pediatric pts participating in SWAY, there were 77 US respondents to the educational survey (mean age, 12 y), 200 HIC respondents (mean age, 13 y), and 492 LMIC respondents (mean age, 12 y, [one respondent did not provide an age]). Pediatric pts in all groups reported that SCD adversely impacted their education. Of the US respondents, 51%, 45%, and 52% agreed that SCD negatively impacted performance on school tests, overall performance at school, and school attendance, respectively. This was a higher rate of agreement for these statements than that reported by pediatric pts from other HIC (25%, 23%, 36%) and LMIC (37%, 41%, 50%). The US respondents also agreed that SCD negatively affected performance on homework (45%), caused them to repeat a year or class (42%), lowered interest in school (36%), and limited educational progression (35%). Again, this was a higher rate of agreement than that reported by pediatric pts from other HIC (26%, 14%, 19%, 20%) and LMIC (37%, 32%, 34%, 29%). Interestingly, the largest differences in reported school impact occurred between the US and HIC, where the US respondents showed nearly two-fold higher agreement for all statements except for reduced attendance. Conversely, there were only minor differences between respondents from the US and LMIC. Full results are presented in the Figure. Conclusions: A higher proportion of pediatric pts in the US reported a negative impact of SCD on schooling compared with those in HIC and LMIC. These results were unexpected but align strongly with the emerging evidence that social determinants prevalent in the US lends itself away from the benefits of living in a resource-rich nation. Figure 1 Figure 1. Disclosures James: GBT: Honoraria; Novartis: Honoraria. Francis-Gibson: Global Alliance of SCD Organizations: Membership on an entity's Board of Directors or advisory committees; Sickle Cell Disease Association of America: Current Employment; Alliance for Regenerative Medicine Foundation for Cell and Gene Medicine: Membership on an entity's Board of Directors or advisory committees; ASH: Membership on an entity's Board of Directors or advisory committees; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees. Minniti: GBT: Consultancy, Research Funding; Novartis: Consultancy, Honoraria; NovoNordisk: Consultancy, Honoraria; Roche: Consultancy, Honoraria. Paulose: Novartis Pharmaceuticals Corporation: Current Employment. Bailey: Novartis Pharmaceuticals: Other: I am an employee of Adelphi Real World, which received payment from Novartis Pharmaceuticals for this research. Rajkovic-Hooley: Novartis Pharmaceuticals: Other: I am an employee of Adelphi Real World, which received payment from Novartis Pharmaceuticals for this research. Osunkwo: Forma Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Health and Services Administration: Research Funding; Patient Centered Outcomes Research Instituted: Research Funding; Micella Biopharma: Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Chiesi: Consultancy; Emmaus: Consultancy; Cyclerion: Consultancy; Acceleron: Consultancy; Global Blood Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Terumo: Consultancy.

scholarly journals COVID Symptoms and COVID Anxiety in Sickle Cell Disease

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 16-17
Author(s):  
Wally R Smith ◽  
Benjamin Jaworowski ◽  
Shirley Johnson ◽  
Thokozeni Lipato ◽  
Daniel M Sop
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Research Funding ◽  
Telephone Survey ◽  
Cell Disease ◽  
Weighted Mean ◽  
The Us ◽  
Associated Symptoms ◽  
At Home

Background Even before the US upswing of the current COVID pandemic, the number of sickle cell disease (SCD) patients coming to hospitals and EDs appeared to fall drastically. This happened despite SCD patients having often been heavy utilizers of the ED and hospital for their iconic vaso-occlusive crises (VOC). Though ambulatory SCD clinics quick converted largely to telehealth in order to comply with stay-at-home orders designed to suppress person-to-person transmission, some SCD patients appeared to avoid care, delay care, or refuse doctors' invitations for care. Presumably patients did so out of COVID fears, but this has not been confirmed in the literature. Further, whether these patients had COVID symptoms but stayed at home has not been studied. As part of quality improvement (QI) to conduct COVID surveillance in an adult sickle cell program, we sought to explain and predict SCD health care utilization patterns we were observing, as well as to determine urgent physical and mental health needs of patients who appeared to be avoiding care. Methods Fifteen staff in the Adult Sickle Cell Medical Home at Virginia Commonwealth University, a large urban academic medical center, conducted a telephone survey ("wellness check"was used when we talked to patients) of all known adults with SCD over 19 days in 2020. A staff member confirmed the patient had SCD, asked permission to proceed, then asked about symptoms consistent with COVID-19. At the end of the telephone survey, respondents wer invited to complete an email survey of sickle cell and COVID-19 utilization attitudes (19-33 items, depending on the response pattern, either drawn from the National Health Interview Survey, from the Adult Sickle Cell Quality of Life Measurement quality of care survey, or drafted by the authors), the Sickle Cell Stress Survey-Adult (SCSS-A, a 10-item previously validated survey), and anxiety and depression (PHQ9 of the PRIME-MD). Results Of 622 adults approached by phone call, 353 responded to the following yes/no screening questions regarding the prior 14 days: fever over 100 F 0/353 (0.00%); cough 3/353(0.01%); difficulty breathing 0/353(0.00%); unexplained shortness of breath 2/353(0.01%); sore throat 2/353 (0.01%); unexplained muscle soreness 2/353(0.01%);contact with anyone who tested positive for COVID-19 2/353(0.01%); testing for COVID 19 6/353(0.02%). For QI purposes, we set a threshold of three or more COVID-associated symptoms or the presence of fever as criteria requiring intense telephone or in-person staff monitoring for the following week. Only three patients met criteria. A total of 219/353 had email surveys sent. Of 63 patients (28.8%) who returned email surveys by June 10, 2020, 35.9% had already managed a "pain attack" at home 4 or more times in the prior 12 months, and 45.5% of these said their bad ER experiences were very or somewhat important in that decision. In the prior 14 days, although 30/64 reported a crisis for at least one day, only 4/64 had visited the Emergency Department for pain. On a 0-10 scale, 21/61 patients endorsed "0" for worry that they would be COVID-infected by going for medical care (weighted mean 3.9), but 18/59 endorsed "10" for worry they were more at risk of COVID because of SCD (weighted mean 6.31), and 22/60 endorsed "10" for worry they would fare worse than others if COVID infected (weighted mean 6.97). Many patients forwent "needed" care (16/62) or delayed "needed" care by at least a day (36/61). Eleven patients met criteria for moderately severe to severe depression on the PHQ-9, and 28/63 somewhat or strongly agreed with the statement "death is always on the back of my mind" on the SCSS-A. Conclusions In adolescents and adults with SCD, many were already reticent to come to the ED for pain, but a significant portion reported delays or avoidance of needed care during the early stages of the US COVID pandemic, and few reported using the ED despite over half reporting at least one crisis day in 14. Patients nonetheless reported very few COVID-associated symptoms. Fears of COVID infection/susceptibility may limit visits for needed sickle cell care among adults. Acknowledgements: Mica Ferlis RN, FNP, Caitlin McManus, RN, FNP, Emily Sushko, RN, FNP, Justin West, RN, Kate Osborne, RN, Stefani Vaughan-Sams, Marla Brannon, BS, Nakeiya Williams, BS Disclosures Smith: GlycoMimetics, Inc.: Consultancy; Emmaeus Pharmaceuticals, Inc.: Consultancy; Novartis, Inc.: Consultancy, Other: Investigator, Research Funding; Global Blood Therapeutics, Inc.: Consultancy, Research Funding; Shire, Inc.: Other: Investigator, Research Funding; NHLBI: Research Funding; Patient-Centered Outcomes Research Institute: Other: Investigator, Research Funding; Health Resources and Services Administration: Other: Investigator, Research Funding; Incyte: Other: Investigator; Pfizer: Consultancy; Ironwood: Consultancy; Novo Nordisk: Consultancy; Imara: Research Funding; Shire: Research Funding.

scholarly journals Clinical and Biomarker Predictors for Avascular Necrosis in Sickle Cell Disease

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 3091-3091
Author(s):  
Michael Rabaza ◽  
Maria Armila Ruiz ◽  
Liana Posch ◽  
Faiz Ahmed Hussain ◽  
Franklin Njoku ◽  
...  
Keyword(s):  
Risk Factors ◽  
Sickle Cell Disease ◽  
Board Of Directors ◽  
Avascular Necrosis ◽  
Sickle Cell ◽  
Research Funding ◽  
Medical Attention ◽  
Cell Disease ◽  
Advisory Committees ◽  
Early Management

Abstract Introduction Sickle cell disease (SCD) affects 1 in 365 African Americans and approximately 25 million people world-wide. A common skeletal system complication is avascular necrosis (AVN), which can cause substantial pain and a reduced quality of life. While early management of AVN is focused on increasing range of motion with physical therapy and pain relief, there are no clear predictors for who is more likely to develop AVN and earlier institution of these preventive measure could help decrease disease progression. Vascular endothelial growth factor (VEGF) is a biomarker of endothelial injury and may indicate reduced vascular supply to the femoral or humeral head. Here we describe potential risk factors and biologic pathways for AVN in SCD, as understanding these may lead to improvements in future monitoring, early detection, and early intervention practices. Methods We investigated clinical and laboratory risk factors associated with AVN in a cohort of 435 SCD patients from our center. Blood samples, clinical, and laboratory data were collected at the time of enrollment during a clinic visit. Genotyping for alpha thalassemia was performed by PCR and the serum concentration of VEGF was measured by ELISA. AVN status was confirmed by review of the medical record and available imaging. We conducted a cross-sectional analysis comparing categorical and linear variables by AVN status using the chi-square and Kruskal-Wallis test, respectively. The independent association of the clinical and laboratory variables with AVN status was determined by logistic regression analysis. The initial model included variables with a P-value &lt; 0.1 on univariate analysis and the final model was ascertained by stepwise forward and backward selection. Median values and interquartile range (IQR) are provided. Results The median age of the cohort was 32 (IQR, 24 - 43) years, 57% (250/435) were female, and 46% (198/435) were on hydroxyurea. AVN was observed in 34% (149/435) of SCD patients. SCD patients with AVN were older, had more frequent vaso-occlusive crises requiring medical attention, and had a higher body mass index (Table I) (P ≤ 0.002). We measured VEGF in 241 of the SCD patients with serum samples available at the time of enrolment. Serum VEGF concentrations trended higher in SCD patients with versus without AVN (420 vs. 359 pg/mL, respectively; P = 0.078). In the multivariate analysis model, AVN was independently associated with increased number of vaso-occlusive crises (OR 1.1, 95% CI: 1.0 - 1.14; P = 0.02), AST concentration (natural log OR 0.5, 95% CI: 0.2 - 0.9; P = 0.03), VEGF concentration (natural log OR 1.4, 95% CI: 1.0 - 1.9; P = 0.047), and tobacco use (OR 1.9, 95% CI: 0.9 - 3.7; P = 0.078). Discussion In conclusion, we demonstrate a high prevalence of AVN in an adult cohort of SCD patients. The presence of AVN was independently associated with a greater frequency of vaso-occlusive pain episodes, which may demonstrate a shared pathophysiology between AVN and vaso-occlusion that merits further investigation. We demonstrate that serum VEGF concentrations are higher in SCD patients with AVN and may be a clinical tool to identify those at high-risk and for earlier intervention for this complication. Figure 1 Figure 1. Disclosures Gordeuk: Modus Therapeutics: Consultancy; Novartis: Research Funding; Incyte: Research Funding; Emmaus: Consultancy, Research Funding; Global Blood Therapeutics: Consultancy, Research Funding; CSL Behring: Consultancy. Saraf: Pfizer: Research Funding; Global Blood Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding.

scholarly journals Non-Invasive Prenatal Diagnosis (NIPD) of Sickle-Cell Disease By Massively Parallel Sequencing of Cell-Free Fetal DNA in Maternal Serum

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 2085-2085
Author(s):  
Yvonne Daniel ◽  
Julia Van Campen ◽  
Lee Silcock ◽  
Michael Yau ◽  
Joo Wook Ahn ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Massively Parallel Sequencing ◽  
Plasma Samples ◽  
Cell Disease ◽  
Cell Free Dna ◽  
Non Invasive ◽  
Free Dna ◽  
Cell Free Fetal Dna

Sickle cell disease (SCD) is the most common genetic haematological disorder worldwide. Around 300.000 affected infants are born every year, including at least 1000 in the United States. Prenatal diagnosis is currently carried out using amniotic fluid or chorionic villus sampling. These invasive procedures are perceived to have a small risk of miscarriage. The availability of non-invasive prenatal diagnosis (NIPD) is predicted to increase uptake of prenatal diagnosis for SCD, as it has no perceived miscarriage risk. NIPD may also be more readily implemented than invasive prenatal diagnosis in the low-resource countries in which SCD is the most prevalent. However, accurate NIPD of autosomal recessive disorders such as sickle cell disease has proven challenging as this requires detection of fetal inheritance of a maternal allele from a mixed maternal-fetal pool of cell-free DNA. We report the development of a targeted massively parallel sequencing assay for the NIPD of fetal SCD using cell-free fetal DNA from maternal plasma. No paternal or previous offspring samples were required. 44 clinical samples were analysed, including 37 plasma samples from pregnant SCD carriers and 7 plasma samples from women with SCD due to Hb SC. We used a relative mutation dosage based approach for the 37 samples from maternal SCD carriers (Hb AS or Hb AC), integrating Unique Molecular Identifiers (UMIs) into the analysis to improve the accuracy of wildtype and mutant allele counts. We used a separate wildtype allele detection approach for the 7 samples from women with compound heterozygous SCD, in whom the detection of wildtype cell-free DNA indicates the presence of a carrier fetus. The success of the assay was evaluated by comparing results with the established fetal sickle status as determined through either invasive prenatal diagnosis or newborn screening. During development, two key factors improved the accuracy of the results: i) Selective analysis of only smaller cell-free DNA fragments enhanced the fetal fraction for all samples, with greater effects observed in samples from earlier gestations. This approach improved diagnostic accuracy: for 3 out of 44 samples, the genotype was inconclusive or incorrect before size selection, but correct after size selection. ii) Modifications to DNA fragment hybridisation capture optimised the diversity of Unique Molecular Identifier-tagged molecules analysed. This led to improvements in the results obtained for 5 samples, with 3 previously inconclusive samples correctly called and 2 previously discrepant results moved into the inconclusive range. In total, 37 results were concordant with the established fetal sickle status; this included 30/37 samples from carrier women and 7/7 samples from women with sickle cell disease due to Hb SC. The remaining 7 carrier samples gave an inconclusive result, which for 3 samples was attributed to a low fetal fraction. Samples from as early as 8 weeks gestation were successfully genotyped. There were no false positive or false negative results. This study is the largest to use NGS-based NIPD on clinical plasma samples from pregnancies at risk of SCD. Efforts to validate the assay on a larger sample cohort and to reduce the inconclusive rate are warranted. This study shows that NIPD for SCD is approaching clinical utility and has the potential to provide increased choice to women with pregnancies at risk of sickle cell disease. Disclosures Silcock: Nonacus Ltd.: Employment.

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