Egyptian Sickle Cell Disease Patients Research Articles

The potential role of increased miR-144 expression in Egyptian sickle cell disease patients

The potential role of increased miR-144 expression in Egyptian sickle cell disease patients

Thrombin activatable fibrinolysis inhibitor plasma levels and TAFI Thr325Ile genetic polymorphism in a cohort of Egyptian sickle cell disease patients and impact on disease severity.

Thrombin is a critical protease modulating thrombosis as well as inflammation, which are one of the main pathophysiological mechanisms in sickle vasculopathy, and its levels were reported to be high in sickle cell disease (SCD). The thrombin-thrombomodulin complex activates the TAFI inhibitor of fibrinolysis, which acts by reducing plasmin affinity for its substrate thus hindering fibrinolysis. We aimed to determine the influence of the Thr325Ile single nucleotide polymorphism (SNP) on TAFI antigen levels and potential effects on the severity of SCD in a cohort of Egyptian patients. Genotyping of Thr325lle polymorphism using Taq-Man SNP genotyping assay and TAFI level measurement using an enzyme-linked immunosorbent assay were performed for 80 SCD patients (45 homozygous HbSS, 16 S/β0 and 19 Sβ+) as well as 80 age- and gender-matched healthy control subjects. Plasma TAFI levels were higher in SCD patients with Thr325Ile polymorphism, yet the difference was not statistically significant (p=.204). SCD patients with polymorphic genotypes had a greater number of hospital admissions (p=.03). Ten patients with acute chest syndrome had the homozygous polymorphic genotype (GG), and all patients with pulmonary hypertension had the polymorphic genotype (six were homozygous [GG] and five were heterozygous [GA]). Patients with SCD complicated with pulmonary hypertension showed significantly higher plasma TAFI levels (p=.044). The analysis of Thr325Ile polymorphisms combined with plasma TAFI levels suggests that the analyzed SNP could influence plasma TAFL levels and SCD disease severity and hospitalization rates, which could be predictors for complex disease.

The impact of MCP1-2518A/G and CCR2-V64I genetic polymorphisms in Egyptian sickle cell disease patients

BackgroundSickle cell disease (SCD) is an inherited genetic disorders of hemoglobin that causes multisystem morbidity. The pathophysiology of SCD is complex and includes HbS polymerization/sickling, hemolysis, endothelial dysfunction and inflammation. Chemokines are proteins playing an important role in the inflammation process and could be involved the context of pro-inflammatory SCD. Some chemokine polymorphism were found to be associated with clinical complication in SCD. Aim of the studyWas to explore the frequency and the possible effect of Monocyte Chemo-attractant Protein 1–2518A/G (MCP1–2518A/G) and Chemokine Receptor 2-V64I (CCR2-V64I) genetic polymorphisms on clinical and laboratory disease-related variables in Egyptian Sickle cell disease patients. Patients and methodsGenotyping of the two genes were performed by PCR-RFLP technique for 80 SCD patients as well as 50 healthy control group. ResultsThe study revealed that the MCP1–2518 polymorphic genotypes (AG & GG) showed no statistically significant difference in the distribution of the polymorphic genotypes between SCD patients and the controls (p = 0.164). While a significantly higher frequency of the mutant variants CCR2-V64I GA/AA among SCD patients than the control subjects were found (p = 0.032). Regarding the clinic-pathological features, the frequency of recurrent infections, vaso-occlusive crisis, severe vaso-occlusive crisis and number of hospitalization/year were higher in patients harbouring the MCP1–2518A/G and CCR2-V64I polymorphic genotypes than the wild genotype, and gall bladder complications were higher in MCP1–2518 G allele patients, whereas surgical splenectomy were higher in CCR2-V64I A allele patients (p < 0.05). In conclusionMCP1–2518A/G and CCR2-V64I genetic polymorphisms may influence the clinical severity of sickle cell disease.

P1475: THE ROLE OF BCL11A AND HBS1L-MYB SINGLE NUCLEOTIDE POLYMORPHISMS IN EGYPTIAN SICKLE CELL DISEASE PATIENTS

Background: Sickle cell disease (SCD) is a debilitating blood disorder with a highly variable phenotype. Inter-individual variation in fetal hemoglobin (HbF) expression is a known and potentially heritable modifier of SCD severity. High HbF levels are correlated with reduced morbidity and mortality. The only currently FDA-approved HbF inducing drug for sickle cell disease (SCD) is hydroxyurea (HU). Genome wide association studies (GWAS) have identified three major quantitative trait loci (QTL) (intergenic region of HBS1L-MYB, BCL11A gene and XmnI site) associated with HbF. Several single nucleotide polymorphisms (SNPs) with persistence of HbF and amelioration of disease severity of β-thalassemia (β-thal) and SCD have been identified. Aims: The aim of the current study is to find the influence of these genetic modifiers, especially BCL11A (rs4671393) and HBS1L-MYB intergenic region (rs9399137) SNPs on the level of HbF, severity of SCD and response to hydroxyurea in Egyptian sickle cell disease patients. Methods: The present study included 100 patients with SCD; 56 patients were diagnosed as homozygous sickle cell anemia (SS) patients, while 44 patients were diagnosed as sickle beta thalassemia patients (Sβ). Genotyping for the genes was done by Real-Time PCR (RT-PCR) technique. Results: BCL11A (rs4671393) SNP showed higher hemoglobin and HbF levels when induced with HU, with significantly higher increment in HbF level post HU therapy as well as a milder clinical phenotype in our Sβ patients’ group. In our SS patients’ group it showed a lower incidence of pneumonia as well as a more effective response to HU treatment. HBS1L-MYB intergenic region (rs9399137) SNPs showed lower reticulocytic counts and serum ferritin levels in our Sβ patients’ group. Summary/Conclusion: In conclusion, our study shows that BCL11A (rs4671393) SNP showed higher hemoglobin and HbF levels when induced with HU, with significantly higher increment in HbF level post HU therapy as well as a milder clinical phenotype in our Egyptian study.

Impact of Superoxide Dismutase Genetic Polymorphism (SOD2 Val16Ala) and Superoxide Dismutase Level on Disease Severity in a Cohort of Egyptian Sickle Cell Disease Patients.

BackgroundOxidative stress plays a pivotal role in the pathophysiology of sickle cell disease (SCD) and its associated disease complications. Superoxide Dismutases (SODs) are protective enzymes against oxidative stress. SOD2 deficiency results in the accumulation of oxidized red cell proteins, increased rate of hemoglobin oxidation, decreased red cell membrane deformability, and subsequently decreased red cells survival.ObjectiveThe current study was designed to determine the effect of SOD2 Val16Ala gene polymorphism (rs4880) on SOD2 level and their possible impact on SCD disease severity in a cohort of Egyptian SCD patients.MethodsGenotyping SOD2 Val16Ala polymorphism by TaqMan allelic discrimination assay for hundred SCD patients and a hundred age-sex matched healthy controls revealed the genotypic and allelic frequencies of the studied polymorphism in the SCD patients were close to that of the controls.ResultsSerum SOD2 level was significantly lower in those having the polymorphic genotypes (p=0.005). SOD2 level inversely correlates with the annual rate of hospitalization (r=−0.023, p= 0.038).ConclusionSOD2 Val16Ala polymorphism was associated with low serum SOD2 level that may predict disease severity.

Serum Level of High-Mobility Group Box Protein 1 as a Potential Treatment Target in Egyptian Sickle Cell Disease Patients

Background:&#x0D; During tissue injury, high mobility group box 1 (HMGB1) is passively released from necrotic cells and actively secreted by inflammatory cells. Extracellular HMGB1 acts as an amplifier of Toll-Like Receptor (TLR)-dependent inflammation rather than a primary trigger of inflammation. We studied HMGB1 quantitative trait locus reference sequence 2249825 (rs2249825) and its serum level in both sickle cell disease (SCD) patients and healthy subjects to explore its possible role in the pathogenesis of vaso-occlusive crises (VOCs).&#x0D; Methods:&#x0D; HMGB1 rs2249825 was assayed in peripheral blood samples using real-time polymerase chain reaction (RT-PCR). While the serum level was assayed using a two-site enzyme-linked immunosorbent technique (ELISA).&#x0D; Results:&#x0D; Both the SCD patients and the control group had comparable HMGB1 rs2249825 genotype frequencies (P-value &gt;0.05). SCD patients at their steady-state showed statistically significantly higher serum HMGB1 levels than the healthy controls, a median of 0.6 ng/ml with a range of 0.1- 85 ng/ml versus a median of 0.3 ng/ml and a range of 0.1-3 ng/ml (P-value &lt;0.001), respectively. Statistically significant skewed high serum HMGB1 in the VOC samples in contrast to the steady-state samples was observed in the SCD patients with a median of 3.2 ng/ml and a range of 0.3-76.4 ng/ml versus a median of 0.2 ng/ml and a range 0.2-7.4 ng/ml (P-value &lt;0.0001), respectively.&#x0D; &#x0D; &#x0D; Conclusion:&#x0D; HMGB1 could have a role in the VOC pathogenesis, hence it is suggested as a potential additive therapeutic target in SCD in general and in vaso-occlusions in specific.&#x0D; Keywords:&#x0D; Sickle cell disease, HMGB1, Hemoglobin S

Retinal microvascular analysis using Fundus Fluorescein Angiography in Egyptian sickle cell disease patients

Abstract Background Sickle cell disease can affect retina of eye via vaso-occulsive changes that occur in micro-vessels of retina which could be analysed by using Fundus Fluorescein Angiography. Aim To analyze macular microvascular alternation in patients with SCD by Fundus Fluorescein Angiography (FFA) and to assess the role of potentially contributory Clinico-pathological factors including Trans-Cranial Doppler, genotypes, hydroxyurea, transfusion therapy and finally iron overload state on the development of macular alterations. Method This was across-sectional study which included 30 Sickle cell disease patients randomly recruited from the Paediatric Haematology clinic, children Hospital, Ain Shams University, Cairo, Egypt. Complete blood count (CBC), Trans-Cranial Doppler (TCD) and Fundus Fluorescein Angiography. Results In our study, there were 30 patients with mean age (14.1± 4.02), 5 patients had abnormal/conditional Trans-Cranial, 15 patients had Vaso-occlusive crises, 11 patients were on regular simple blood transfusion; all 30 studied sickle cell disease patients had normal Fundus Fluorescein Angiography and eye examination and only one patient hadabnormal visual acuity;A 29 years oldgirl who had five attacks of cerebral strokes last year, on regular simple blood transfusion and Hydroxyurea treatment with abnormal TCD and recurrent Vaso-occlusive crises in last two years, Although her vision is hand movement yet Fundus Fluorescein Angiography was normal. Conclusion we didn’t find any Retinal microvascular alternation in our studied SCD patients using Fundus Fluorescein Angiography, we related our results to the fact that our studied SCD patients were young and all our studied patients were on hydroxyurea therapy with fair compliance, further studies using large sample size are warranted in order to illustrate the utility of Fundus Fluorescein Angiography (FFA) as a tool for better detection of sickle retinopathy.

Association between BCL11A, HSB1L-MYB, and XmnI γG-158 (C/T) gene polymorphism and hemoglobin F level in Egyptian sickle cell disease patients.

Sickle cell disease (SCD) is a monogenic disease characterized by multisystem morbidity and highly variable clinical course. Inter-individual variability in hemoglobin F (HbF) levels is one of the main modifiers that account for the clinical heterogeneity in SCD. HbF levels are affected by, among other factors, single nucleotide polymorphisms (SNPs) at the BCL11A gene and the HBS1L-MYB intergenic region and Xmn1 gene. Our aim was to investigate HbF-enhancer haplotypes at these loci to obtain a first overview of the genetic situation of SCD patients in Egypt and its impact on the severity of the disease. The study included 100 SCD patients and 100 matched controls. Genotyping of BCL11A (rs1886868 C/T), HBS1L-MYB (rs9389268 A/G) and Xmn1 γG158 (rs7842144 C/T) SNPs showed no statistically significant difference between SCD patients and controls except for the hetero-mutant genotypes of BCL11A which was significantly higher in SCD patients compared with controls. Baseline HbF levels were significantly higher in those with co-inheritance of polymorphic genotypes of BCL11A + HSB1L-MYB and BCL11A + Xmn1. Steady-state HbF levels, used as an indicator of disease severity, were significantly higher in SCD-Sβ patients having the polymorphic genotypes of HSB1L-MYB. Fold change of HbF in both patient groups did not differ between those harboring the wild and the polymorphic genotypes of the studied SNPs. In conclusion, BCL11A, HSB1L, and Xmn1 genetic polymorphisms had no positive impact on baseline HbF levels solely but had if coexisted. Discovery of the molecular mechanisms controlling HbF production could provide a more effective strategy for HbF induction.

L-Selectin P213S and Integrin Alpha 2 C807T Genetic Polymorphisms in Pediatric Sickle Cell Disease Patients.

Sickle cell disease (SCD) is an autosomal recessive hemoglobinopathy characterized by increased cellular adhesiveness. Vaso-occlusion (VOC) is the most prevalent disease complication of SCD that could be altered by genetic factors. L-Selectin and integrin alpha 2 (ITGA2) are 2 adhesion molecules linked to vasculopathy and inflammation. The current study aimed at detecting the prevalence of genetic variants of L-selectin and ITGA2 as possible molecular modulators and novel therapeutic targets in a cohort of pediatric SCD patients. Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism technique for 100 SCD patients and 100 age and gender-matched unrelated healthy controls. The homomutant genotype of ITGA2 C807T was significantly higher in SCD patients compared with controls (P=0.001) and confirmed almost a 3-fold increased risk of moderate and severe attacks of VOC. There are significant adverse effects caused by the polymorphisms of ITGA2, and hence Egyptian SCD patients could benefit from the targeted therapies specifically against ITGA2 to ameliorate the severe course of the disease and improve the quality of life. However, further studies of genotypes and expression levels of these adhesion molecules during the attacks of VOC are recommended.

Interleukin-1\u03b2 and interleukin-6 gene polymorphisms in Egyptian sickle cell disease patients

BackgroundSickle cell disease (SCD) is a disorder characterized by a heterogeneous clinical outcome. Interleukin-1β (IL-1β) and interleukin-6 (IL-6) are important mediators of inflammatory response. Genetic modifiers that alter cytokine levels may contribute to the clinical variability of SCD. The present study investigated the associations of IL-1β + 3954 C>T and IL-6 (− 174G>C and − 597 G>A) gene polymorphisms with clinical and laboratory data in SCD patients. The study was conducted on 100 SCD patients (59 sickle cell anemia patients “SS” and 41 sickle beta thalassemia patients “Sβ”). Fifty age- and sex-matched healthy volunteers were included as a control group. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique was used for the detection of IL-1β and IL-6 gene polymorphisms.ResultsThe homomutant genotypes of IL-1β (+ 3954 C>T), IL-6 (− 174G>C), and IL-6 (− 597 G>A) were infrequently presented among SCD patients and control group. No significant differences were detected between SS, Sβ patients, and control group as regards the genotypic frequencies and allele distributions of the studied polymorphisms. As regards the clinical complications, the mutant genotypes of IL-1β (+ 3954 C>T) had a significantly higher frequency among Sβ patients with splenomegaly. Hemoglobin is significantly lower in SS patients with mutant allele (AA and GA) for IL-6 (− 597 G>A) (P = 0.005), while Sβ patients with mutant genotype for IL-6 (− 597 G>A) had significantly higher total leucocytic count (P = 0.031).ConclusionIL-1β (+ 3954 C>T), IL-6 (− 174G>C), and IL-6 (− 597G>A) polymorphisms are not associated with disease phenotype. However, IL6 polymorphism (− 597 G>A) might predispose to underlying inflammatory process.

IL-Iβ +3954 C / T Polymorphism and Its Clinical Associations in Egyptian Sickle Cell Disease Patients

Background: Sickle cell disease (SCD) is a hereditary disorder characterized by hemolytic anemia with different clinical manifestations. Patients with SCD exhibit a chronic inflammatory state and reduced length and quality of life. Interleukin-1 β (IL-1β) is important in acute and chronic diseases; and its single nucleotide polymorphisms (SNP) have been considered as predictors of prognosis in several inflammatory conditions. This study aimed at exploring IL-1β (+3954C/T) SNP as a potential genetic modifier and/or predictor of SCD clinical and laboratory phenotypes. Materials and Methods: This cross-sectional study involved 50 SCD patients and 50 age, sex and ethnicity-matched healthy individuals. IL-1β (+3954C/T) SNP was identified by PCR-RFLP. Associations between IL-1β (+3954 C/T) SNP and the clinical and laboratory profiles of patients with SCD were studied. Results: It was found that the homozygous mutant genotype TT was significantly higher in cases compared to controls [13(26%) vs. 3(6%) respectively; p=0.006, OR (95%CI): 5.505(1.460-20.756)]. The homozygous mutant genotype TT was associated with a higher mean pulmonary arterial pressure when compared to the CC and CT genotype (42.62 vs. 33.49 mmHg, p<0.001). Conclusion: There is an increased prevalence of the mutant genotype of IL-1β +3954 SNP in Egyptian SCD patients. Regarding disease complications, the mutant genotype was more prevalent in cases complicated by pulmonary hypertension. These findings point to the possible role of IL-1β +3954 SNP in the pathophysiology of SCD and its manifestations.

Vitamin D and Nonskeletal Complications among Egyptian Sickle Cell Disease Patients.

Lower levels of vitamin D have been documented in many patients with sickle cell disease (SCD), but data are still inconclusive regarding the association between vitamin D deficiency (VDD) and the occurrence or the severity of various SCD complications. Our study aimed to detect the prevalence of vitamin D deficiency among Egyptian patients with SCD and to associate it with the clinical course of the disease. We measured the level of 25-hydroxy vitamin D in 140 children (age from 4.3 to 15.5years), 80 patients with SCD and 60 controls using enzyme-linked immunosorbent assay. Vitamin D was deficient in 60% of SCD compared to 26.7% of controls. Severe VDD was significantly higher in SCD patients than controls. Patients were divided into 2 groups; Normal group (32 patients) and Deficient group (48 patients). There were statistically significant differences between the 2 groups regarding their age, height percentile, the presence of clinical jaundice, and osseous changes (P values 0.043, 0.024, 0.001, and 0.015, respectively). Hemoglobin and hematocrit values were significantly lower in Deficient group (P values 0.022 and 0.004, respectively) while the levels of aspartate aminotransferase, lactate dehydrogenase, and total and indirect bilirubin were significantly higher in the same group (P values 0.006, 0.001, 0.038, and 0.016, respectively). The frequency of blood transfusions, hospitalization, and vasoocclusive crisis previous year as well as the history of bone fracture and recurrent infections proved to be significantly higher in Deficient group. These findings suggest that VDD may play a role in the pathogenesis of hemolysis and other complication of SCD. Vitamin D monitoring and supplementation in patients with SCD should be implemented as a standard of care to potentially improve health outcomes in these affected patients.

Protein Z and Endothelin-1 genetic polymorphisms in pediatric Egyptian sickle cell disease patients.

Sickle cell disease (SCD) is a monogenic disease associated with multisystem morbidity. Vasculopathy caused by delicate imbalance between coagulation and endothelial systems plays a pivotal role in disease course. As Protein Z and Endothelin-1 genetic polymorphisms may increase the thrombotic risk, the aim of the current work was to verify the possible impact of Protein Z (PROZ G79A) and Endothelin-1 (EDN1 G5665T) polymorphisms on the clinic-laboratory features of the SCD in a cohort of Egyptian pediatric patients. Genotyping of Protein Z G79A and Endothelin-1 G5665T was carried out by polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) assay for 100 SCD patients and 100 controls. Protein -Z G79A polymorphism was not associated with vascular complications in the studied SCD patients. Endothelin-1 G5665T polymorphism was associated with pulmonary dysfunction (pulmonary artery hypertension and acute chest syndrome) and severe vaso-occlusive crises (VOC). Endothelin-1 G5665T polymorphism could be considered as a molecular predictor for pulmonary dysfunction and severe VOC in SCD. Further researches with larger cohorts are recommended to understand the pathophysiology of SCD and to explain the inter-patients' variability of disease severity.

Urinary Transforming Growth Factor β-1 as a Marker of Renal Dysfunction in Sickle Cell Disease

Sickle cell disease (SCD) is a genetic disorder that results in deformity of red blood cells. Renal dysfunction affects 5-18% of patients with SCD. To date, few studies have described urinary levels of transforming growth factor β-1 (TGF-β1), which is a marker of fibrosis, as a biomarker in identifying patients at risk of developing renal disease in SCD. The aim of this study is to determine prevalence of sickle cell nephropathy in Egyptian SCD patients. We aimed also to evaluate the association of urinary TGF-β1 with other conventional biomarkers of renal damage in SCD patients to identify a novel renal biomarker for early diagnosis of sickle nephropathy. We examined 40 SCD patients, 21 with sickle cell anemia, 16 sickle thalassemia, and three with sickle trait. We compared them to 20 control children with matched age and sex. The study was held in the time period between May 2013 and December 2013 in the Hematology Clinic, New Cairo University Children Hospital, Cairo, Egypt. Urinary excretion of TGF-β1 was 7.07±1.91ng/mL in SCD patients versus 2.23±0.76ng/mL in control children (p < 0.001). SCD patients had elevated estimated glomerular filtration rate (177.44±35.6mL/min/1.73m(2)), denoting a state of glomerular hyperfiltration. 47.5% of SCD patients had microalbuminuria. Urinary TGF-β1 correlated positively with microalbuminuria and estimated glomerular filtration rate (p=0.001 and p=0.018, respectively). We concluded that urinary TGF-β1 may serve as a marker of early renal injury in SCD.

Glutathione S-transferase gene polymorphisms (GSTM1, GSTT1, and GSTP1) in Egyptian pediatric patients with sickle cell disease.

Sickle cell disease (SCD) complications are associated with oxidative stress. Glutathione S-transferases (GSTs) are a group of enzymes that protect against oxidative stress. The aims of this study was to evaluate the prevalence of GSTM1, GSTT1, and GSTP1 gene polymorphisms among homozygous sickle cell anemia patients and to investigate the possible association between the presence of these polymorphisms and SCD severity and complications. Genotyping the polymorphisms in GSTT1 and GSTM1 genes was performed using the multiplex polymerase chain reaction (PCR) method. The GSTP1 ILe105Val polymorphism was determined using PCR-restriction fragment length polymorphism. GSTM1 null genotype was significantly associated with increased risk of severe vaso-occlusive crises (VOC) (odds ratio = 1.52, 95% confidence interval = 0.42-5.56, P = 0.005). We found no significant association between GST genotypes and frequency of sickle cell-related pain, transfusion frequency, disease severity, or hydroxyurea treatment. GSTM1 gene polymorphism may be associated with risk of severe VOC among Egyptian SCD patients.