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.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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/ß0 and 19 Sß+) as well as 80 age- and gender-matched healthy control subjects. RESULTS: 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). CONCLUSION: 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.

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

Background: Oxidative 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. Objective: The 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. Methods: Genotyping 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. Results: Serum 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). Conclusion: SOD2 Val16Ala polymorphism was associated with low serum SOD2 level that may predict disease severity.

The prevalence of combined vascular endothelial growth factor, endothelial nitric oxide synthase and thrombin-activatable fibrinolysis inhibitor genetic polymorphisms among Egyptian patients with recurrent spontaneous abortion.

AIM: As angiogenesis is an essential step for chorionic villi formation. Vascular endothelial growth factor (VEGF) is essential for endothelial cell proliferation. Endothelial nitric oxide synthase (eNOS) is a powerful playmaker in hypoxia-induced angiogenesis. Thrombin-activatable fibrinolysis inhibitor (TAFI) regulates both fibrinolysis and inflammation. Genetic alterations of these factors may lead to recurrent spontaneous abortion (RSA). We aimed to investigate the combined genetic variants of VEGF G-1154A and two eNOS genetic variants: T-786C promoter region and intron 4 variable number of tandom repeats in addition to TAFI C-1040T among RSA patients. METHODS: The study included 50 patients with RSA and 50 healthy controls. Polymerase chain reaction and restriction fragment length polymorphism were used for genotyping. RESULTS: Both genetic alterations of eNOS confirmed at least a sixfold increase of RSA risk. Interestingly, they were associated with TAFI C-1040Tgenetic variant in 21 patients, eight of them had both studied eNOS genetic alterations and TAFI C-1040Tgenetic variant, while each eNOS genetic variant associated with TAFI C-1040Tconfirmed an almost one and half fold increase risk of RSA. CONCLUSION: These findings highlighted the role of eNOS and nitric oxide metabolism in RSA and opened the gate to investigate the interaction of vasoconstrictive and fibrinolytic inhibitor systems.

Breast cancer resistance protein (BCRP) gene expression in a cohort of adult Egyptian patients with acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML), an aggressive clonal disease, is genetically heterozygous. The prognostic role of expression of Breast Cancer Resistance Protein (BCRP) gene, which behaves as a multidrug transporter, in adult AML is ambiguous. OBJECTIVE: The objective is to assess the level of mRNA expression of BCRP gene in newly diagnosed cytogenetically normal adult Egyptian AML patients; and to clarify its potential influence and association between therapeutic responsiveness and disease free survival. METHODS: The BCRP gene expression was evaluated by quantifying its mRNA using real time RT-PCR in fifty newly diagnosed cytogenetically normal adult AML patients and 20 healthy normal controls. The expression was evaluated in relation to clinical and prognostic factors, response to treatment and the survival rate. RESULTS: BCRP mRNA was over expressed in adult AML patients compared to controls. This study showed a positive statistical correlation between BCRP gene expression and the percent of CD34 expression. Statistical analysis did not reveal any association between BCRP expression level and chemotherapeutic responsiveness or disease free survival rate. CONCLUSION: The significance of BCRP gene expression and its function in AML is very complicated, therefore more standardized clinical studies are needed.

Thrombin-Activatable Fibrinolysis Inhibitor Gene Polymorphism (TAFI1040C/T) in Women With Recurrent Spontaneous Abortion.

Recurrent spontaneous abortion (RSA) is defined as 3 or more consecutive pregnancy failures. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a plasma zymogen that regulates both fibrinolysis and inflammation. The TAFI 1040C/T polymorphism could alter the circulating levels of TAFI with a reduced capacity to remove the fibrin clots from the circulation; therefore, it could be considered a molecular risk factor for RSA. The TAFI 1040C/T polymorphism was studied in 50 patients with RSA by polymerase chain reaction-restriction fragment length polymorphism technique and compared to 50 age- and gender-matched healthy volunteers as a control group to verify its possible association with RSA. In case group, the wild genotype (C/C) and heterozygous genotype (C/T) did not reduce the risk of RSA (odds ratio: 0.368 and 0.767, respectively), even when compared to the number of RSA ( P = .71). A higher frequency of C allele in the control group and a higher frequency of T allele in the case group were observed but with no statistical significance. In conclusion, our study revealed that TAFI 1040C/T could not be considered a molecular predictive factor for RSA in Egyptians.

Detection of expression of IL-18 and its binding protein in Egyptian pediatric immune thrombocytopenic purpura.

Immune thrombocytopenic purpura (ITP) is an autoimmune disorder, characterized by dysfunctional cellular immunity including the presence of activated platelet specific autoreactive T cells that recognize and respond to autologous platelet antigens. Autoreactive T cells drive the generation of platelet reactive autoantibodies by B cells as well as T-cytotoxic cell-mediated lysis of platelets. Interleukin-18 (IL-18) is a mediator of T helper type 1 cell responses synergistically with IL-12 that initiate and promote host defense and inflammation. IL-18 has a specific binding protein (IL-18BP) which belongs to the immunoglobulin superfamily. In the present study, serum level and messenger RNA( mRNA) expression of IL-18 as well as IL-18BP mRNA expression were measured in peripheral blood mononuclear cells (PBMNCs) of 100 Egyptian pediatric patients with ITP (70 acute and 30 chronic). In addition to this, we recruited 80 healthy volunteers in order to investigate the possible association between the imbalance of IL-18 and IL-18 BP expressions and the pathogenesis of ITP. IL-18 serum level and mRNA expression were not elevated in cases more than in the control group, but IL-18 mRNA was higher in chronic cases when compared to the acute ones (p=0.031) and there was a good negative correlation between the platelet count and serum IL-18. IL-18 BP m-RNA was slightly elevated in cases more than in the control group (95% Confidence interval=1.15-2.01). Our results were not supportive for previous findings of elevated IL18/BP mRNA ratio in ITP patients. This could be referred to the fact that autoimmune diseases are complex genetic disorders, therefore further studies on polymorphisms affecting IL-18 gene expression as well as kinetics of IL-18 expression are required to evaluate the role of interleukin 18 and its binding protein in the pathogenesis of ITP.

Apolipoprotein E gene polymorphism and the risk of left ventricular dysfunction among Egyptian ß-thalassemia major.

In Egypt, ß-thalassemia is the most common hereditary hemolytic anemia. Cardiac dysfunction, secondary to iron overload with formation of oxygen free radicals, is the most common cause of death in ß-thalassemia patients. This study was designed to determine whether the allelic genotype of apolipoprotein E (Apo E), which exhibits antioxidant properties, could represent a genetic risk factor for the development of left ventricular (LV) dysfunction in ß-thalassemia major. Fifty Egyptian ß-thalassemia major patients were subjected to echocardiography to assess LV function. Apo E genotyping by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) was done for all patients in addition to 50 age and sex matched healthy control subjects. Patients were classified into three groups. Group I and II were clinically asymptomatic. Group II subjects had evidence of LV dilatation, while Group III patients had clinical and echocardiographic findings of LV failure. Apo E4 allele was significantly higher among Group II and III than in controls. In conclusion, Apo E4 allele can be considered as a genetic risk factor for LV dysfunctions in ß-thalassemic patients. It could be used as predictive indicator for additional risk of LV failure, particularly in asymptomatic patients with LV dilatation, requiring a closer follow-up, to prevent further disease progression.

Blood transfusion among thalassemia patients: A single Egyptian center experience.

BACKGROUND: Although red cell transfusions are lifesavers for patients with thalassemia, they are responsible for a series of complications and expose the patients to a variety of risks. MATERIAL AND METHODS: This cross-sectional study included 464 Egyptian beta(ß) thalassemia major patients whose age ranged between 10 months and 31 years (mean 10.2 ± 6.6 years). All patients were subjected to thorough history taking with special emphasis on blood transfusions regarding rate of blood transfusion, type of received blood, and history of previous transfusion reactions in addition to type of chelation and compliance to iron chelation therapy and history of diabetes. Serum ferritin and pretransfusion hemoglobin assessment were done for all patients. RESULTS: The mean pretransfusion hemoglobin level was 5.7 ± 1.16 g/dl. Allergic reactions were observed in 3.9% of the patients during the period of the study, while the history of previous allergic reaction was given by 72% of the patients. Deferiprone showed better compliance (58.6%) than deferoxamine (26.3%). The prevalence of diabetes was 10.1% among the studied group. On comparing diabetics to nondiabetics, serum ferritin, transfusion intervals, and age were statistically higher among diabetics (P<0.001). CONCLUSION: Lower pretransfusion hemoglobin and high rate of prevalence of diabetes, in addition to better compliance to deferiprone than deferoxamine, were detected among the patients.

DNMT3B promoter polymorphism and risk of immune thrombocytopenic purpura in pediatric Egyptians.

Idiopathic (immune) thrombocytopenic purpura (ITP) is a heterogeneous clinical disorder characterized by immune-mediated platelet destruction. Epigenetic changes in gene expression, including DNA methylation and histone modifications, might contribute to autoimmunity. Polymorphisms of the DNA methyltransferase 3B (DNMT3B) gene may influence DNMT3B activity on DNA methylation and increase the susceptibility to several diseases. The current study investigated the association between a single nucleotide polymorphism (SNP) in the promoter of DNMT3B gene and the risk for ITP in pediatric Egyptians. DNMT3B SNP was genotyped by PCR-restriction fragment length polymorphism in 71 pediatric ITP patients and 82 healthy controls matched for age and sex. The C/C wild genotype was not detected in ITP patients or in the controls. The frequencies of the T/T and C/T genotypes were 93.9 and 6.1% in the controls and 91.5 and 6.1% in ITP patients, respectively. There was no significant difference in either genotypes or allelic distribution between ITP patients and the controls. In conclusion, this polymorphism was almost equally distributed between ITP patients and the controls. These results demonstrated that this SNP may not be used as a stratification marker to predict the susceptibility to childhood ITP in Egypt.

FcγRIIa and FcγRIIIa genetic polymorphisms in a group of pediatric immune thrombocytopenic purpura in Egypt.

Immune thrombocytopenic purpura (ITP) is an acquired autoimmune disorder caused by the production of antiplatelet antibodies. The current case-control study aimed at detecting the frequency of FcγRIIa-131H/R and FcγRIIIa-158F/V genes polymorphism in Egyptian children with ITP as genetic markers for ITP risk, and to clear out their possible role in choosing the treatment protocols of ITP. To achieve this aim, FcγRIIa genotyping was tested by PCR-restriction fragment length polymorphism (RFLP) technique, whereas FcγRIIIa genotyping was tested by nested PCR followed RFLP analysis. The current case-control study was conducted on 92 children with ITP; 12 acute and 80 chronic cases and 90 controls. The V allele and FcγRIIIa FV heterotype were significantly higher in ITP patients and conferred increased ITP risk [odds ratio (OR) = 1.96 and 2.55, respectively]. The frequency of FcγRIIa H allele was significantly higher among chronic ITP patients. In conclusion, FcγRIIIa gene polymorphism may contribute to susceptibility to ITP. Moreover, analysis of the FcγR polymorphisms in ITP patients could influence the effectiveness of medications and selection of the line of treatment.