Genomic Approaches to Identifying Risk for Pulmonary Artery Hypertension among Individuals with Sickle Cell Disease.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1442-1442
Author(s):  
Damian Silbermins ◽  
Laura M. De Castro ◽  
Jude C Jonassaint ◽  
Shiaowen David Hsu ◽  
Marilyn J. Telen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sickle Cell Disease ◽  
Pulmonary Artery ◽  
Sickle Cell ◽  
Whole Blood ◽  
Gene Signature ◽  
Pulmonary Artery Hypertension ◽  
Gene Set Enrichment Analysis ◽  
Cell Disease ◽  
Gene Signatures

Abstract Pulmonary artery hypertension (PAH) occurs in 30–50% of adult patients with sickle cell disease (SCD), with mortality ranging from 16 to 50% and a median survival of 25 months. Our objective was to use gene expression profiling to develop a gene signature predictor for PAH through the analysis of gene expression of blood cells from SCD patients with or without PAH. We hypothesized that these gene signatures could allow us to identify patients at risk for PAH, as well as to generate hypotheses as to the pathophysiology of PAH in SCD. We used Affymetrix U133A2 GeneChip to determine the RNA expression of both whole blood and leukocytes using PAXgene and Leukolock methods, respectively. The study population included patients homozygous for HbS or with HbSβ0 thalassemia. Subjects with PAH were ≥18 years old, in steady state, and had PAH either by 2D echo (TR jet ≥ 2.7 m/sec) or right-sided catheterization (mean PA pressure ≥ 30 mmHg). Patients were excluded if they were pregnant, had co-existing rheumatologic conditions or other inflammatory diseases, were on chronic transfusion therapy or had had a vaso-occlusive episode in the previous 4 weeks. The control subjects were patients with SCD but without PAH (TR jet ≤ 1.8 m/sec or mean PA pressure <25 mmHg). Hierarchical clustering based on the gene expression pattern from 7 patients with PAH and 6 controls showed a trend for the clustering of SCD patients with PAH away from SCD patients without PAH. This trend was present for the gene expression in both whole blood and leukocytes. A Bayesian regression analysis was then performed to identify a set of predictor gene signatures for the PAH phenotype (Figure 1) in SCD. Finally, using gene set enrichment analysis, we found that the leukocytes from patients with PAH were highly enriched in the gene sets deriving from hematopoietic stem cells, corroborating the hypothesis of hyperhemolysis and higher blood cell turnover in this population. Other pathways showing upregulation in PAH were PTEN, TGFβ, cyclin D1, WNT and PPAR. Although these data are preliminary, they suggest that PAH in SCD does indeed have a distinct gene signature profile that may become useful in identifying risk for PAH prospectively, as well as in directing further investigation into the pathogenesis of PAH in SCD. Figure Figure

Pulmonary Artery Occlusion Pressure May Overdiagnose Pulmonary Artery Hypertension in Sickle Cell Disease

CHEST Journal ◽  
2011 ◽  
Vol 140 (4) ◽  
pp. 881A
Author(s):  
Sunil Sharma ◽  
Renuka Kadali ◽  
Ramesh Daggubati ◽  
Jimmy Efird ◽  
Hadi Chohan ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Pulmonary Artery ◽  
Sickle Cell ◽  
Pulmonary Artery Occlusion Pressure ◽  
Artery Occlusion ◽  
Pulmonary Artery Hypertension ◽  
Occlusion Pressure ◽  
Cell Disease

Pulmonary Artery Hypertension in Children with Sickle Cell Disease: Is Chronic Transfusion Protective?.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1210-1210
Author(s):  
Kristin Joyce ◽  
Craig Sable ◽  
Brenda Martin ◽  
Caterina P. Minniti
Keyword(s):  
Blood Pressure ◽  
Sickle Cell Disease ◽  
Pulmonary Artery ◽  
Sickle Cell ◽  
Vena Cava ◽  
Systolic Pressure ◽  
Pulmonary Artery Hypertension ◽  
Right Atrial ◽  
Cell Disease ◽  
Systemic Pressure

Abstract Background Studies in adults with sickle cell disease (SCD) suggest an increased prevalence of pulmonary artery hypertension (PAHTN) with associated increased morbidity and mortality. These findings have not been validated in children. Methods The digital echocardiography (echo) database at Children’s National Medical Center was searched for echos performed on patients with SCD from 1999 to 2006. Patients on chronic transfusions undergo regularly scheduled studies; other patients are referred for a variety of indications including murmurs, cardiomegaly, hypoxia, chest pain, and respiratory distress. Echo reports and digital images were reviewed and the following information was recorded: Chronic transfusion, date of study, blood pressure, cardiac structure, ventricular function, presence of tricuspid regurgitation (TR), and velocity of TR. The estimated right ventricular (RV) pressure was calculated using modified Bernoulli equation (adding 5 mm Hg for estimated right atrial pressure if the inferior vena cava was not dilated). The ratio of RV systolic pressure to systemic systolic blood pressure was calculated. All studies with TR velocities of < 3 m/sec or a RV to systemic ratio of less than one third were considered to be normal. Results: The SCD database has 1060 patients ages 0 to 21 years; 166 echos were performed in 104 routine patients and 72 echos in 47 children while on chronic transfusions. TR could be measured in 56 routine and 20 transfusion studies. Comorbidities were present in 11 studies (7 patients) in the routine group: structural heart disease (4 ), constrictive pericarditis (1 ), significant obstructive airway disease (1 ), and pneumonia requiring mechanical ventilation (1 ). There were no comorbidities in the transfusion group. The mean TR velocity, estimated RV pressure, and RV to systemic pressure ratios were higher in the routine group; however when patients with comorbidities were removed, this difference was no longer statistically significant. Routine (n=55) Routine/no comorbidities (n=44) Transfused (n=20) 1p = 0.01 transfused vs. routine; p = 0.11 transfused vs. routine/no comorbidities 2p < 0.01 transfused vs. routine; p = 0.09 transfused vs. routine no comorbidities 3p = 0.01 transfused vs. routine; p = 0.13 transfused vs. routine/no comorbidities 1TR velocity (m/sec) 2.54 ± 0.48 2.30 ± 0.30 2.30 ± 0.30 Range 1.67–3.93 Range 1.67–3.19 Range 1.70–2.76 2RV pressure (mm Hg) 31.8 ±10.5 29.2 ± 6.6 26.5 ± 5.6 Range 16.2–67.8 Range 16.2–45.7 Range 16.6–36.4 3RV/systemic pressure ratio 0.29 ± 0.11 0.26 ± 0.064 0.23 ± 0.065 Range 0.16–0.78 Range 0.16–0.41 Range 0.14–0.38 There were 6 routine studies (2 when patients with comorbidities were removed) and no transfusion studies with a TR velocity above 3.0 m/sec. There were 23 routine studies (18 when patients with comorbidities removed) and 6 transfusion studies with a TR velocity between 2.5 and 3.0 m/sec. The ratio of RV to systemic pressure was greater than one third in 11 routine patients (5 when patients with comorbidities were removed) and 1 transfusion patient. Conclusions PAHTN is present in a small number of children with SCD and may be exacerbated by other medical problems. Chronic transfusion may be protective against PAHTN. Prospective analysis of this population is warranted.

scholarly journals Type I Interferon Gene Signature in Peripheral Blood Mononuclear Cells of Sickle Cell Disease Patients and a Connection to RBC Alloimmunization

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 26-27
Author(s):  
Emaan Madany ◽  
June Young Lee ◽  
Jeanne E. Hendrickson ◽  
David R Gibb
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Whole Blood ◽  
Gene Signature ◽  
Small Sample ◽  
Type I ◽  
Healthy Controls ◽  
Cell Disease ◽  
Interferon Gene

Background RBC alloimmunization is a clinically significant issue in transfusion medicine; patients with sickle cell disease have an increased risk of alloantibody production (30-50% of SS patients) compared to that of other hospitalized patients (3-10%). However, mechanisms underlying the increased frequency of alloimmunization in sickle cell patients are poorly understood. In previous studies, inflammation in the recipient has been shown to promote alloimmunization. Transfusion models, type 1 interferons (IFNα/β) and Interferon Stimulated Genes (ISGs) have been shown to promote alloimmunization in mice. Other studies have shown that patients with inflammatory autoimmune diseases express an IFNα/β signature which may contribute to the increased frequency of alloimmunization in these populations. One recent study reported significantly elevated ISGs in neutrophils as well as evidence that IFNα is upregulated in SS patients compared to controls. Given the chronic inflammatory state in SS patients, we sought to determine the role of PBMCs and whether they also expressed an IFN gene signature that contributes to the increased frequency of alloimmunization. Methods The expression of the ISG, myxovirus resistance protein 1 (MxA), was measured in the blood of SS patients with more patients with SS disease (SS, n=13) and race matched healthy controls (ββ, n=3) by whole blood immunoassay (ELISA). qPCR was performed on 5 previously established ISGs to determine an IFN score, a measure of overall gene expression, from whole blood and IFNβ stimulated PBMCs of SS patients (SS, n=15) and healthy race matched controls (ββ, n=5). A LEGENDplex™ Human Anti-Virus Response Panel assay was used to determine the expression of various type 1 IFNs, cytokines and ISGs in patients with SS disease (SS, n=15) and healthy race matched controls (ββ, n=5). Results SS patients had significantly elevated levels of MxA (mean ± standard error of the mean, SS MxA = 12.27 ng/mL ± 15.68) compared to control patients without SS (ββ MxA = 1.52 ng/mL± 0.26, p< 0.05) (Figure 1 A) . The Legendplex showed a significant increase in IL-6, IL-10 and the ISG, IP-10. (SS IP-10= 147.81 pg/mL ± 49.24) (ββ IP-10 = 68.85 pg/mL ±10.70, p<0.01) (Figure 1 B) Analyzing the 5 ISGs, we saw a trend towards a higher IFN score in patients with SS disease than healthy controls in whole blood; this difference was significant in PBMCs stimulated with IFNB (IFN Score SS = 20.76 ± 17.18 ,ββ = 0.00 ± 3.71 , p<0.01) (Figure 1 C). Discussion SCD is a complex disease with many environmental and genetic factors that play roles in the severity of the disease. Any number of these factors may influence the high rates of alloimmunization found in sickle cell patients. We found increased cytokines, ISGs and IFN scores in SS patients compared to healthy controls. These findings suggest the presence of an IFNα/β gene signature in patients with sickle cell disease. Due to the relatively small sample size, we are unable to determine a correlation between alloantibodies and MxA levels or high IFN scores with this cohort. Further studies will allow us to determine if the increased interferon gene signature plays a role in the increased alloimmunization burden that these patients experience. Disclosures No relevant conflicts of interest to declare.

scholarly journals Pulmonary Artery Occlusion Pressure May Overdiagnose Pulmonary Artery Hypertension in Sickle Cell Disease

2013 ◽  
Vol 36 (9) ◽  
pp. 524-530 ◽  
Author(s):  
Sunil Sharma ◽  
Jimmy Efird ◽  
Renuka Kadali ◽  
Sanjay Mehra ◽  
Hadi Chohan ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Pulmonary Artery ◽  
Sickle Cell ◽  
Pulmonary Artery Occlusion Pressure ◽  
Artery Occlusion ◽  
Pulmonary Artery Hypertension ◽  
Occlusion Pressure ◽  
Cell Disease

Amplified Expression Profiling of Platelet Transcriptome Reveals Global Activation of Arginine Metabolic Pathways in Patients with Sickle Cell Disease.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1536-1536
Author(s):  
Nalini Raghavachari ◽  
Xiuli Xu ◽  
Jose Villagra ◽  
Greg Kato ◽  
Peter J. Munson ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Expression Profiles ◽  
Ischemia Reperfusion ◽  
Functional Characterization ◽  
Gene Set Enrichment Analysis ◽  
Clinical Samples ◽  
Cell Disease ◽  
Activated State

Abstract In sickle cell disease, ischemia-reperfusion injury and intravascular hemolysis produce endothelial dysfunction and vasculopathy characterized by reduced nitric oxide (NO) and arginine bioavailability. Recent functional studies of platelets in patients with sickle cell disease reveal a basally activated state, suggesting that pathological platelet activation may contribute to sickle cell disease vasculopathy. Studies were therefore undertaken to globally examine transcriptional signaling pathways in platelets that may be dysregulated in sickle cell disease. We demonstrate and validate here the feasibility of comparative platelet transcriptome studies on clinical samples from single donors, by the application of RNA amplification followed by microarray-based analysis of 54,000 probe sets. Data mining for platelet specific or abundant genes identified 118 genes that showed more than a 100-fold increase in transcript expression level compared to all other cells in the database. Most of these genes were clearly annotated as platelet-specific and 84% of these transcripts overlapped with the platelet abundant genes identified in previous gene expression studies. On comparing the platelet gene expression profiles in 18 patients with sickle cell disease in steady state to 12 African American controls, at a 3-fold cut-off and 5% false discovery rate, we identified >100 differentially expressed genes, including multiple genes involved in arginine/NO metabolism and redox homeostasis. Further functional characterization of these pathways using Gene Set Enrichment Analysis, real time PCR, arginase enzymatic assay, and polyamine quantification revealed arginase II-mediated catabolism and diversion of arginine from NO signaling and polyamine synthesis to proline formation. These studies suggest a potential pathogenic role for platelet arginase and ornithine decarboxylase antizyme and provide a novel framework for the study of disease-specific platelet biology.

scholarly journals Identifying Potential Drug Targets for Sickle Cell Disease through Gene Expression and Pathway Analysis of GEO Data

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 15-16
Author(s):  
Sharjeel Syed ◽  
Jihad Aljabban ◽  
Jonathan Trujillo ◽  
Saad Syed ◽  
Robert Cameron ◽  
...  
Keyword(s):  
Gene Expression ◽  
Amino Acid ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Drug Targets ◽  
Meta Analysis ◽  
Cell Disease ◽  
Blood Samples ◽  
Disease Modifying Therapies ◽  
Disease Modifying

Background: The pathogenesis of sickle cell disease (SCD) and its complications have been well characterized down to the molecular level. However, there remains a relative dearth of disease modifying therapies that reduce the frequency and number of vas-occlusive crises, hospitalizations, and deaths. Recent advancements in utilizing hydroxyurea and L-glutamine, which both impact unique disease pathways, should pave way for the identification of other molecular pathways as ideal drug targets. In this regard, our meta-analysis serves to identify key genes and associated pathways that are differentially expressed in SC patients. Methods: We employed our STARGEO platform to tag samples from the NCBI Gene Expression Omnibus and performed meta-analysis to compare SC and healthy control transcriptomes. For the meta-analysis, we tagged 285 peripheral blood samples from SC patients and 86 samples from healthy subjects as a control. We then analyzed the signature in Ingenuity Pathway Analysis to elucidate top disease functions from our analysis. Results: From our meta-analysis, we identified iron homeostasis signaling, NRF2-mediated oxidative stress response, cell senescence, and pyrimidine interconversion/biosynthesis as top canonical pathways that were upregulated in the peripheral blood samples from SC patients. Top upstream regulators included membrane associated protein and transporter ABCB6, non-coding RNY3, and erythroid maturation transcription factors GATA1, KLF1, and HIPK2 (with predicted activation). The most upregulated genes included inflammatory modulators RNF182 and IFI27, the latter of which has been shown to inhibit vascular endothelial growth and repair. Several membrane-associated protein coding genes such as GYPA, RAP1GAP, and PAQR9 were also upregulated in the SC samples. RAP1GAP is known to modulate neutrophil cell adhesion and homing while PAQR9 has roles in regulating protein quality control: a role also seen in similarly upregulated YOD1, a deubiquitinating enzyme involved in trafficking of misfolded proteins. Expectedly, also upregulated were HBBP1 and SOX6, which regulate globin genes and have been shown to silence γ-globin expression. Lastly, SLC6A19, the neutral amino acid transporter mutated in Hartnup disease, was also upregulated. Of the downregulated genes, WASF3, a member of the Wiskott-Aldrich syndrome protein family, has been linked to poor survival in many malignancies, including AML and CMML, but has not previously been linked to SCD pathogenesis. ENKUR was also downregulated and has been annotated as a tethering protein to cation channels as well as linked to pathways involving vascular leakage. SIGLEC10, which binds to vascular adhesion proteins, is a key suppressor of inflammatory responses to damage; it's downregulation along with ELAPOR1, a transmembrane protein involved in cellular response to stress, was also observed. Finally, based off the focus genes in our analysis we identified several networks with most being involved in amino acid metabolism, cellular assembly, function, and maintenance, hematological disease, and organismal injury. The top pathway is illustrated in Figure 1. Conclusions: Our study illustrates differentially expressed gene activity in SCD consistent with known pathophysiology such as immune response, endothelial damage and adherence, heme metabolism, and globin regulation. We also showed evidence of genes not previously studied in SCD, which may have novel roles such as those part of the ubiquitin-proteasome system like YOD1 and RNF182. Additionally, while some genes in our analysis like EKLF and GAT1 have been shown to enhance δ-globin expression, paving way for possible drug therapies for B-hemoglobinopathies, others like IFI27, PAQR9, RAP1GAP, ENKUR, SIGLEC10, WASF3, and SOX9 have yet to be studied as mediators of disease pathogenesis in SCD. A target to SOX9, a known suppressor of γ-globin, or ABCB6, a known modulator of erythroid cell shape and hydration, have particularly promising potential as disease modifying therapies. Finally, HIPK2, HBBP1, and SLC6A19 have previously been shown to have intriguing effects on hydroxyurea dosing and responsivity in SC patients and may also be candidate target molecules to enhance existing therapies. These data identify potential candidate pathways for mechanistic studies seeking to confirm a causative role in the pathogenesis of sickle cell disease. Disclosures No relevant conflicts of interest to declare.

scholarly journals Whole Blood Adhesion to VCAM-1 and P-Selectin and RBC Mechanical Fragility Can be Compromised in Long COVID-19 Patients with Sickle Cell Disease

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 959-959
Author(s):  
Michael Tarasev ◽  
Marta Ferranti ◽  
Cidney Allen ◽  
Xiufeng Gao ◽  
Kayla Topping ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Blood Cell ◽  
Sickle Cell ◽  
Whole Blood ◽  
Stock Options ◽  
Membrane Stability ◽  
Cell Disease ◽  
Adhesive Properties ◽  
Rbc Membrane ◽  
Privately Held

Abstract Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can cause severe vascular complications associated with endothelial dysfunction and systemic inflammation. COVID19-specific IgG are detectable within a week of infection. Long COVID-19 has been described in patients continuing to exhibit symptoms after the virus is no longer detectable in the respiratory secretions, including fatigue, dyspnea, headache, and brain fog. The recent FAIR Health study reviewed a total of 1,959,982 COVID-19 patients for the prevalence of long COVID symptoms and reported that 23.2% had at least one post-COVID symptom [1]. The underlying biologic mechanisms of long COVID remain unclear, thus treatments are limited to symptomatic relief and supportive care. Many long COVID symptoms are consistent with systemic inflammation and impaired oxygen delivery observed in individuals with sickle cell disease (SCD), in turn associated with elevated blood cell adhesion and decreased red blood cell (RBC) stability. The aim of this study was to determine if deleterious changes in in blood cell properties related to adhesion and membrane stability under stress can be associated with the symptoms of long COVID-19. In this work we evaluated 7 SCD patients that were diagnosed with SARS-Cov-2 and tracked their recovery using semiquantitative IgG and blood cell function assays. Methods: Blood samples were collected by the Foundation for Sickle Cell Disease (SCD) Research from SCD (homozygous SS, n=6) patients coming for regular or urgent clinic visit with SARS-CoV-2 serological and blood cell functions tests performed per the standard of care. Semiquantitative IgG assay was performed using DXi-80 (Beckman Coulter). Flow adhesion of whole blood to VCAM-1 (FA-WB-VCAM)and P-Selectin (FA-WB-Psel) substrates were determined by counting the cells that remain adherent in a microfluidics channel after perfusion with whole blood 1:1 diluted with HBSS buffer and washed by reversed flow at 1 dyne/cm 2. Red blood cell mechanical fragility (RBC MF) was measured as hemolysis induced by an oscillating cylindrical magnet with periodic non-invasive probing of cell-free hemoglobin fraction. Six individuals with SCD recovering from SARS-Cov-2 with biomarker data available both before and for more than 3 months after the infection (179±62 days) were included in the study. Results: IgG levels varied from less than 0.1 to 37, with positive values being defined as IgG > 1. The median estimated half-life of IgG decline was 53 days ranging from 25 to 90 days (the last, for the hospitalized patient). Averaged for IgG positive (IgG+) and IgG negative (IgG-) conditions, combining pre- and post-infection IgG- conditions, values of patient hemoglobin (Hb), FA-WB-VCAM, FA-WB-Psel, and RBC MF cell properties lacked statistical significance (under both a paired t-test and population statistics). Hb levels remained essentially unchanged regardless of the time from infection or IgG status. However, FA-WB-VCAM, FA-WB-Psel, and RBC MF were all significantly elevated after SARS-Cov-2 seroconversion and remained elevated despite declining IgG levels (e.g., Fig. 1). These increases in biomarker values were statistically significant for both FA-WB-VCAM and RBC MF, and were approaching significance for FA-WB-Psel (p<0065). These increases were highly patient-specific with potential return to pe-infection values observed in some cases at about 5-6 months after the infection. A qualitative review of the medical records indicated a new subjective report of fatigue in 5 of 6 patients. Longer observations are required to determine if abnormal blood cell adhesive properties and RBC membrane instability are mechanisms of long-COVID-19 pathophysiology. Conclusions: Whole blood adhesion to both p-selectin and VCAM-1 as well as RBC membrane stability can be significantly impaired in convalescent SARS-Cov-2 patients suggesting an association with long COVID-19. New and emerging treatments that modify whole blood adhesive properties and RBC membrane stability should be investigated for their potential to accelerated recovery from long COVID-19. Health F. A Detailed Study of Patients with Long-Haul COVID: An Analysis of Private Healthcare Claims; White Paper. June 15, 2021 Disclosures Tarasev: Functional Fluidics: Current holder of stock options in a privately-held company. Ferranti: Functional Fluidics: Current holder of stock options in a privately-held company. Allen: Functional Fluidics: Current Employment. Gao: Functional Fluidics: Current Employment. Topping: Functional Fluidics: Current Employment. Ferranti: Functional Fluidics: Current Employment. Makinde-Odesola: Functional Fluidics: Other: conduct research for academic program. Hines: Functional Fluidics: Current holder of stock options in a privately-held company.

Abnormal right ventricular to pulmonary artery coupling in sickle cell disease

2021 ◽  
Author(s):  
Tatiana Ballez ◽  
Flore Samantha Benghiat ◽  
Céline Dewachter ◽  
Ana Roussoulières ◽  
Jean-Luc Vachiéry
Keyword(s):  
Sickle Cell Disease ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
Sickle Cell ◽  
Cell Disease
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