Klotho Polymorphisms and Priapism In Sickle Cell Disease.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1653-1653 ◽  
Author(s):  
Claudia R Lustosa Souza ◽  
Marily M Azevedo Shimmoto ◽  
Perla Vicari ◽  
Martha Mariana A S Arruda ◽  
Marina Roizenblatt ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Vascular Function ◽  
Conflicts Of Interest ◽  
Significant Proportion ◽  
Cell Disease ◽  
Specific Pcr ◽  
Allele Specific ◽  
Male Patients ◽  
Allele Specific Pcr

Abstract Abstract 1653 Background: Sickle cell disease (SCD) is a monogenic disorder with phenotypic heterogeneity, possibly determined by polymorphisms (SNPs) in genes whose products modify the pathophysiology of the disease. Priapism is one of the most common vaso-occlusive complications of SCD, and it occurred in more than 30% of males. The Klotho (KL) gene appears to be associated with vascular function and nitric oxide biology and the presence of SNPs could affect its function. Association between KL and priapism in SCD patients was suggested by Nolan et al. in 2004. However, other authors could not confirm this finding (Elliot et al., 2007). Objective: We decided to evaluate the relevance of SNPs rs2249358, rs211234 and rs9536314 to the occurrence of priapism in patients with SCD followed at Outpatient clinic at Escola Paulista de Medicina/UNIFESP. Methods: Forty male patients with SCD were enrolled, 39 (97.5%) with sickle cell anemia (SS) and one (2.5%) SC hemoglobinopathy. The manifestation of priapism was identified through analyses of medical records. The SNP rs2249358 was identified by PCR followed by restriction with XbaI. The other SNPs, rs211234 and rs9536314, were analyzed by allele specific PCR. Statistical analysis: t test, Chi2 or Fisher. This study was approved by Ethical Committee, and all patients agreed in participate. Results: The median age of the patient was 28.5 years-old (20-68 y.o.). Fourteen out of 40 patients had priapism (35%), each one with SS disease. The group of patients with priapism were older (32.5 y.o., 25–68 y.o.) than the group without this manifestation (27.5 y.o., 20–56 y.o.) (p=0.03). There was no statistical difference in the distribution of the SNPs rs211234 and rs9536314 between the two groups of patients (p=0.51 and p= 0.09, respectively). Regarding the distribution of SNP rs2249358, the group with priapism presented 8 individuals (57.1%) with GG genotype, 5 (35.7%) with AA and 1 (7.17%) with AG, whereas in the group without priapism, the distribution was different: 5 (19.2%) with GG, 7 (26.9%) with AA and 14 (53.8%) with AG genotype (p=0.0212). When we compare the presence of at least one A allele (AA or A-) with the G allele in homozygosis (GG), we observed that the A allele has a protector effect (OR: 0.1786; CI: 0.04232–0.7535) (p=0.031). Conclusions: In a relatively small group of patients with SCD, it was observed a significant proportion of individuals with priapism, which reinforces the importance of this manifestation. We also observed correlation between SNP rs2249358 of KL gene and priapism, as suggested previously. Disclosures: No relevant conflicts of interest to declare.

Potential Therapeutic Applications of Jak2 Inhibitors in Beta-Thalassemia and Sickle Cell Disease,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3187-3187
Author(s):  
Carla Casu ◽  
Pedro Ramos ◽  
Luca Melchiori ◽  
Ella Guy ◽  
Eliezer A. Rachmilewitz ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Combination Therapy ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Significant Proportion ◽  
Beta Thalassemia ◽  
Spleen Size ◽  
Cell Disease ◽  
Erythroid Progenitors ◽  
Jak2 Inhibitors

Abstract Abstract 3187 ß-Thalassemia and sickle cell disease (SCD) are the most common genetic red blood cell (RBC) disorders characterized respectively by limited production of aberrant ß-globin chains. In both cases, chronic transfusions and iron chelation are required to treat the anemia and/or formation of abnormal RBC. In ß-thalassemia, anemia stimulates erythropoietin (Epo) synthesis, which in turn leads to increased erythropoiesis and development of hepatosplenomegaly, often resulting in the need for splenectomy. Recently, we demonstrated that erythroid cells from ß-thalassemic mice have a hyper-activation of Jak2, a kinase that mediates the signaling triggered by the binding of Epo to the Epo receptor. This led us to hypothesize that Jak2 inhibitors could be utilized to minimize erythroid expansion in this disorder, limiting splenomegaly. A Jak2 inhibitor (Tg101209 or Tg) was first tested in mice affected by ß-thalassemia intermedia (th3/+). Two doses of Tg (150 and 100 mg/Kg/day) were given orally for 10 days. Tg administration induced a mild decrease of hemoglobin levels (8.8±0.2, 8±0.2 and 7.8±0.2g/dL for placebo, Tg 100 mg/Kg and Tg 150 mg/Kg treated mice, respectively. p<0.05) and in the number of reticulocytes (approximately 75% of the levels seen in controls, p<0.05). Splenomegaly was also reduced in Tg-treated mice (up to 60%; p<0.05), the extent of this effect correlating with the dosage used. Reduction of splenomegaly was associated with a decrease in the number of erythroid progenitors in this organ (p<0.05) and trend toward normalization of the splenic architecture. These data support our hypothesis that, in ß-thalassemia, splenomegaly is associated with increased erythroid proliferation and it can be alleviated by administration of Jak2 inhibitors, with only a mild increase in anemia. We further tested the effect of Tg in other anemias associated with extramedulary hematopoiesis (EMH) and splenomegaly, including SCD. Administration of the drug to mice affected by SCD led to a significant worsening of anemia (more pronounced than that seen in th3/+ mice) and a proportional reduction of splenomegaly and EMH. We then evaluated the outcome of combining Tg with blood transfusion, a common therapy in b-thalassemia and SCD. In b-thalassemia, massively enlarged spleens are believed to sequester a significant proportion of circulating RBC, thereby limiting their lifespan and the efficacy of transfusion regimens. We hypothesize that decreasing splenomegaly by administration of Jak2 inhibitors could increase the efficacy of transfusion. This was first tested in th3/+ animals. In this case, transfusion alone was sufficient to increase the hemoglobin (Hb) levels approximately 3 g/dL and reduce the spleen size to 65% of that seen in non-transfused controls. In this model, the combined effect of transfusion and administration of Tg was more effective, the spleen size been 50% of non-transfused controls (p<0.05). We further tested this approach in mice affected by ß-thalassemia-major (th3/th3), for which transfusion is required for survival and massive splenomegaly develops rapidly. Administration of Tg together with transfusion led to a greater increase in Hb levels compared to transfusion alone (9.3±0.4 vs 7.3±0.5g/dL, p<0.05). This was likely a consequence of reduced splenomegaly and decreased sequestration of RBCs in Tg/transfused mice. Lastly, we tested combination therapy in a mouse model of SCD. Mice treated with Tg and transfusion exhibited slightly lower levels of Hb than transfused controls (Hb=9.7±0.2g/dL versus Hb=10.9±0.2g/dL). However, compared to the control, mice receiving combination therapy exhibited a larger percentage of donor RBCs, while endogenous erythropoiesis was markedly suppressed along with the production of sickle RBCs (1.3±0.3×106 RBC/ul compared to transfused-controls exhibiting 2.7±0.3×106 RBC/ul). In summary, administration of Jak2 inhibitors might reduce the production of pathological cells that, together with preservation of the splenic architecture, could minimize the propensity of patients to thrombotic events. Furthermore, suppression of endogenous erythropoiesis and reduction of the transfusion regimen would be expected to also reduce iron accumulation, making it easier to prevent its toxic effects through chelation therapy. Disclosures: No relevant conflicts of interest to declare.

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.

scholarly journals American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support

2020 ◽  
Vol 4 (2) ◽  
pp. 327-355 ◽  
Author(s):  
Stella T. Chou ◽  
Mouaz Alsawas ◽  
Ross M. Fasano ◽  
Joshua J. Field ◽  
Jeanne E. Hendrickson ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Iron Overload ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Guideline Development ◽  
Practice Research ◽  
Evidence Based ◽  
Red Cell ◽  
Cell Disease ◽  
American Society

Background: Red cell transfusions remain a mainstay of therapy for patients with sickle cell disease (SCD), but pose significant clinical challenges. Guidance for specific indications and administration of transfusion, as well as screening, prevention, and management of alloimmunization, delayed hemolytic transfusion reactions (DHTRs), and iron overload may improve outcomes. Objective: Our objective was to develop evidence-based guidelines to support patients, clinicians, and other healthcare professionals in their decisions about transfusion support for SCD and the management of transfusion-related complications. Methods: The American Society of Hematology formed a multidisciplinary panel that was balanced to minimize bias from conflicts of interest and that included a patient representative. The panel prioritized clinical questions and outcomes. The Mayo Clinic Evidence-Based Practice Research Program supported the guideline development process. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to form recommendations, which were subject to public comment. Results: The panel developed 10 recommendations focused on red cell antigen typing and matching, indications, and mode of administration (simple vs red cell exchange), as well as screening, prevention, and management of alloimmunization, DHTRs, and iron overload. Conclusions: The majority of panel recommendations were conditional due to the paucity of direct, high-certainty evidence for outcomes of interest. Research priorities were identified, including prospective studies to understand the role of serologic vs genotypic red cell matching, the mechanism of HTRs resulting from specific alloantigens to inform therapy, the role and timing of regular transfusions during pregnancy for women, and the optimal treatment of transfusional iron overload in SCD.

scholarly journals Single tube allele specific PCR: a low cost technique for molecular screening of sickle cell anaemia in Nigeria

2018 ◽  
Vol 18 (4) ◽  
pp. 995
Author(s):  
Emuejevoke T Toye ◽  
Guido Van Marle ◽  
Wendy Hutchins ◽  
Olayinka Abgabiaje ◽  
Joy Okpuzor Okpuzor
Keyword(s):  
Sickle Cell ◽  
Sickle Cell Anaemia ◽  
Low Cost ◽  
Molecular Screening ◽  
Single Tube ◽  
Specific Pcr ◽  
Allele Specific ◽  
Allele Specific Pcr

scholarly journals TheCCR5Δ32Polymorphism in Brazilian Patients with Sickle Cell Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Mariana Pezzute Lopes ◽  
Magnun Nueldo Nunes Santos ◽  
Eliel Wagner Faber ◽  
Marcos André Cavalcanti Bezerra ◽  
Betânia Lucena Domingues Hatzlhofer ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Statistical Significance ◽  
Population Sample ◽  
Selective Advantage ◽  
Northeastern Brazil ◽  
Control Group ◽  
Cell Disease ◽  
Specific Pcr

Background. Previous studies on the role of inflammation in the pathophysiology of sickle cell disease (SCD) suggested that theCCR5Δ32allele, which is responsible for the production of truncated C-C chemokine receptor type 5 (CCR5), could confer a selective advantage on patients with SCD because it leads to a less efficient Th1 response. We determined the frequency of theCCR5Δ32polymorphism in 795 Afro-Brazilian SCD patients followed up at the Pernambuco Hematology and Hemotherapy Center, in Northeastern Brazil, divided into a pediatric group (3 months–17 years,n=483) and an adult group (18–70 years,n=312). The adult patients were also compared to a healthy control group (blood donors, 18–61 years,n=247).Methods. TheCCR5/CCR5Δ32polymorphism was determined by allele-specific PCR.Results. No homozygous patient for theCCR5Δ32allele was detected. The frequency of heterozygotes in the study population (patients and controls) was 5.8%, in the total SCD patients 5.1%, in the children 5.4%, in the adults with SCD 4.8%, and in the adult controls 8.1%. These differences did not reach statistical significance.Conclusions. Our findings failed to demonstrate an important role of theCCR5Δ32allele in the population sample studied here.

Genetic Polymorphisms Associated with Priapism in Sickle Cell Disease.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 789-789
Author(s):  
Laine Elliott ◽  
Allison E. Ashley-Koch ◽  
Jude Jonassaint ◽  
Jennifer Price ◽  
Jason Galloway ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Linkage Disequilibrium ◽  
Sickle Cell Disease ◽  
Candidate Genes ◽  
Sickle Cell ◽  
P Value ◽  
Cell Disease ◽  
P Values ◽  
History Of ◽  
Male Patients

Abstract Priapism, a painful and prolonged erection, has been reported to occur in 30–45% of male patients with sickle cell disease (SCD). However, little is known about the pathological processes and genetic risk factors that contribute to the occurrence of priapism. The identification of genetic variables that are associated with priapism may therefore help define both critical pathophysiologic mechanisms not otherwise apparent, as well as patients at increased risk. We examined genetic variation in our sample of 199 unrelated, adult (&gt;18 years), male patients with Hb SS and Hb Sβ0-thalassemia, 83 (42%) of whom reported a history of priapism. Candidate genes for association with priapism were identified based on their involvement in adhesion, coagulation, inflammation, and cell signaling. Additionally, we examined genes involved in NO biology (NOS2, NOS3, SOD1, SLC4A1). Finally, we also examined polymorphisms in the KLOTHO gene, which has previously been associated with priapism. We examined a total of 389 SNPs in 48 candidate genes. Except for the gene encoding the β2 adrenergic receptor, SNP genotyping was performed by TaqMan, using Assays-on-Demand or Assays-by-Design genotyping products (Applied Biosystems). Allele tests were used to detect genetic associations with priapism. Strong evidence of association was found for SNP rs7526590 in the transforming growth factor-β receptor, type III (TGFBR3) gene (p=.00058), SNP rs10244884 in the aquaporin (AQP1) gene (p=.00068), and SNP rs3768780 in the integrin αV (ITGAV) gene (p=0.00090). A second ITGAV SNP (rs3768778), in linkage disequilibrium (r2=.59) with the first, also showed association with priapism (p=.00888). The A1 subunit of coagulation factor XIII (F13A1) had four SNPs (hcv1860621, rs1032045, rs1674074, rs381061) with p-values less than 0.010 (p-values = 0.00156, 0.00415, 0.00648, and 0.00712, respectively). The linkage disequilibrium among these F13A1 SNPs is negligible (r2 &lt;.15). We also adjusted for multiple testing using the Benjamini-Hochberg procedure (significance threshold &lt;.10). SNP rs7526590 in TGFBR3, SNP rs10244884 in AQP1 and SNP rs3768780 in ITGAV each had a false discovery rate (FDR) p-value of .09834. SNP rs1674074 in F13A1 had an FDR p-value of .12733. The other SNPs in F13A1 had large FDR p-values, close to .30. We did not detect an association between priapism and genetic variation in the Klotho gene, as was previously reported by Nolan et al. (2005). Specifically, SNPs rs2249358, rs211234 and rs211239 showed a virtually identical distribution of genotypes for individuals with and without a history of priapism. However, our population is not identical to the previous study, which included patients as young as 10 years old. In conclusion, our data support the hypothesis that genetic variation is associated with risk for priapism among males with SCD and suggest that genes involved in the TGFβ pathway, coagulation, cell adhesion and cell hydration pathways may be important.

Polymorphisms in TNFα Are Associated with Cerebrovascular Events in Sickle Cell Disease.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1540-1540 ◽  
Author(s):  
Latorya A Barber ◽  
Allison E Ashley-Koch ◽  
Melanie E. Garrett ◽  
Karen L Soldano ◽  
Marilyn J. Telen
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Umbilical Vein ◽  
Acute Chest Syndrome ◽  
Cell Disease ◽  
Data Set ◽  
Clinical Complications ◽  
Cerebrovascular Events ◽  
Increased Risk

Abstract Abstract 1540 Poster Board I-563 Tumor necrosis factor alpha (TNFα) is a pro-inflammatory cytokine that stimulates phagocytosis, neutrophil recruitment, and expression of adhesion molecule VCAM-1. Plasma levels of TNFα have been found to be increased in sickle cell disease (SCD), and in vitro studies show that TNFα causes increased adherence of sickle red blood cells to human umbilical vein endothelial cells. A polymorphism in the promoter region of the TNFα gene has previously been associated with stroke in children with SCD (Hoppe et al., 2007). The current study was designed to identify associations of additional TNFα single nucleotide polymorphisms (SNPs) with SCD clinical complications. We analyzed five SNPs in the TNFα gene in 509 DNA samples of SCD patients from Duke University, University of North Carolina at Chapel Hill, and Emory University. In our data set, cerebrovascular events (CVEs), including overt stroke, seizures, and transient ischemic attacks, occurred in 133 out of 509 SCD patients (26.1%). SNP genotyping was performed using Taqman genotyping assays from Applied Biosystems. Due to low minor allele frequencies (<0.05) for all the SNPs examined, genetic associations with SCD clinical complications were examined by using allele tests. After controlling for age, gender, and use of hydroxyurea, two of the five TNFα SNPs, rs2228088 and rs3093665, were significantly associated with CVEs (p=0.013 and 0.029, respectively). The odds that SCD patients with a G allele at rs2228088 suffered from CVEs were 0.485 times that for patients with the T allele, suggesting that the G allele had a protective effect. The odds of having the A allele at rs3093665 and suffering from CVEs was also reduced, at 0.45 compared to the C allele. Neither SNP was found to be in linkage disequilibrium (LD) with any of the other SNPs analyzed (r2≤0.002). There was also strong association of SNP rs2228088 with acute chest syndrome (ACS; p=0.003), occurring in 382 out of 509 SCD patients (75%). However, in this analysis, the G allele was associated with increased risk for ACS (OR=2.313). In addition to the association with CVEs, the SNP rs3093665 was also significantly associated with priapism (p=0.03), reported by 86 of 223 male SCD patients (38.6%). In this analysis, the A allele was protective, as had been observed for CVE (OR=0.188). Additionally, we found no difference in steady state plasma TNFα levels between genotypes for the two SNPs. The functional significance of these SNPs is presently unknown. SNP rs2228088 is a synonymous SNP located in the coding region, and rs3093665 is located in the 3' untranslated region of the TNFα gene. While the G to T change at SNP rs2228088 does not translate to a change in amino acid sequence, the A to C change at SNP rs3093665 may affect mRNA stability due to its location. It is also possible that one or both of these SNPs is in LD with another functionally relevant SNP. Our findings thus support previous data implicating TNFα polymorphisms in risk for central nervous system events. Interestingly, ACS has been previously associated with seizures, stroke and altered mental status in adults and children with SCD (Vinchinsky et al., 2000) and with silent cerebral infarcts and reversible posterior leukoencephalopathy syndrome in children with SCD (Henderson et al., 2003). However, in our dataset, ACS and the occurrence of CVEs were not associated (p=0.24). Further studies are required to elucidate these and other factors that potentially correlate with SCD clinical complications. Disclosures No relevant conflicts of interest to declare.

Measurement of Urine Pyridinoline and Deoxypyridinoline as Markers of Increased Bone Degradation in Sickle Cell Disease.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2572-2572
Author(s):  
Erfan Nur ◽  
Willem Mairuhu ◽  
Dees P. Brandjes ◽  
Ton van Zanten ◽  
Bart J. Biemond ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Bone Resorption ◽  
Sickle Cell ◽  
Conflicts Of Interest ◽  
Healthy Controls ◽  
Cell Disease ◽  
Skeletal Involvement ◽  
Asymptomatic Patients ◽  
Bone Degradation ◽  
Painful Crisis

Abstract Abstract 2572 Poster Board II-549 Introduction: Sickle cell disease (SCD) is commonly manifested through skeletal involvement. Besides the characteristic acute musculoskeletal pain, SCD is also associated with chronic skeletal complications such as osteopenia and osteoporosis. During bone resorption, the collagen cross-links pyridinoline (PYD) and deoxypyridinoline (DPD) are released into circulation with subsequent urinary excretion. Measurements of urinary PYD and DPD could serve as valuable tools in detecting osteoporosis in the follow-up of SCD patients but perhaps also in determining the severity of bone infarction during painful crises. Therefore we compared urinary concentrations of PYD and DPD of SCD patients during asymptomatic state and painful crisis with those of race- and age-matched healthy controls. Methods: Urinary concentrations of PYD and DPD, adjusted for urine creatinine, were measured in SCD patients both during asymptomatic state (n=38) and painful crisis (n=27) and healthy controls with normal HbA hemoglobin (n=25) using high performance liquid chromatography (HPLC). Results: PYD and DPD concentrations were higher in asymptomatic SCD patients compared to controls ((54.8 (41.5–68.6) vs. 44.1 (37.7–49.9),P=0.005 and 11.6 (9.3–15.2) vs. 8.5 (6.8–10.4),P=0.004 respectively), with further increments during painful crisis (63.3 (51.8–76.0),P=0.041 and 15.3(13.0–21.5),P=0.003 respectively). In the asymptomatic patients levels of PYD and DPD were significantly correlated to the degree of hemolysis. Conclusion: In sickle cell patients bone resorption is increased and significantly correlated to the degree of hemolysis, compatible with their susceptibility to osteopenia and osteoporosis. Measurement of pyridinoline and deoxypyridinoline could have additional value as biomarkers of osteoporosis in SCD. During painful crises a further increment in bone degradation was observed. Disclosures: No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document