Evaluation of oxidative stress-related genetic variants for predicting stroke in patients with sickle cell anemia.

Overt stroke in adults with sickle cell anemia (SCA) continues to be a major cause of morbidity and mortality, while no evidence-based strategy for prevention has been reached so far. Although transcranial Doppler ultrasonography represents the most important tool for identifying young patients with SCA at risk of primary stroke, strategies for stroke prediction in adulthood remain challenging. Emerging data suggest that oxidative stress may exert a pivotal role in the pathogenesis of ischemic brain injury. Combining these pieces of evidences with the well-known genetic contribution to the development of stroke in SCA, we hypothesized that genetic variants related to the biology of oxidative stress could be used to identify adult patients at higher risk of stroke. Overall, 499 unrelated patients with SCA aged >18 years were genotyped for SOD2 Val16Ala (rs4880), GPX3 T-568C (rs8177404), GPX3 T-518C (rs8177406), GPX3 T-65C (rs8177412), and CAT01 C-262 T (rs1001179) polymorphisms, along with α-thalassemia status and ß-globin gene haplotypes. Of these, only the SOD2 Val16Ala polymorphism was associated with stroke. SOD2 Val16Ala polymorphism was independently associated with risk of stroke (odds ratio: 1.98; 95% confidence interval [CI]: 1.18-3.32; P = .009) and with the long-term cumulative incidence of stroke (hazard ratio: 2.24, 95% CI: 1.3-3.9; P = .004). In summary, we provide evidence that oxidative stress-related genetic variants, in particular, the SOD2 Val16Ala polymorphism, may represent a simple and inexpensive alternative for identifying patients at risk of stroke.

Combined genotypes of the MBL2 gene related to low mannose-binding lectin levels are associated with vaso-occlusive events in children with sickle cell anemia

Abstract Sickle cell anemia (SCA) presents heterogenous clinical manifestations that cannot be explained solely by alterations to hemoglobin (Hb); other components such as endothelial adhesion, thrombosis and inflammation may be involved. The mannose-binding lectin (MBL) has an important role in innate immunity and inflammatory diseases. In this report, we describe an association between MBL2 polymorphism related to low production of serum MBL and the frequency of vasoocclusive events (FVOE) in children ≤ 5 years old with SCA (p = 0.0229; OR 5.55; CI 1.11-27.66). Further studies are needed to explore the role of low MBL2 in the pathophysiology of vasoocclusive events in SCA.

Combined genotypes of the MBL2 gene related to low mannose-binding lectin levels are associated with vaso-occlusive events in children with sickle cell anemia.

Sickle cell anemia (SCA) presents heterogenous clinical manifestations that cannot be explained solely by alterations to hemoglobin (Hb); other components such as endothelial adhesion, thrombosis and inflammation may be involved. The mannose-binding lectin (MBL) has an important role in innate immunity and inflammatory diseases. In this report, we describe an association between MBL2 polymorphism related to low production of serum MBL and the frequency of vasoocclusive events (FVOE) in children ≤ 5 years old with SCA (p = 0.0229; OR 5.55; CI 1.11-27.66). Further studies are needed to explore the role of low MBL2 in the pathophysiology of vasoocclusive events in SCA.

TNF-α and IL-10 polymorphisms increase the risk to hepatocellular carcinoma in HCV infected individuals.

Hepatitis C virus (HCV) is the major cause of hepatocellular carcinoma (HCC). The risk to develop HCC increases with the severity of liver inflammation and hepatic fibrosis. It is believed that a balance between the releases of pro- and anti-inflammatory cytokines will determine the clinical course of HCV and the risk to develop HCC. The inteleukin-10 (IL-10) and the tumor necrosis factor alpha (TNF-α) play key roles in the Th1 and Th2 balance during the inflammatory response against HCV. The aim of the present study was to investigate the association between polymorphisms in TNF-α -308 G>A (rs1800629), IL-10 -1082 G>A (rs1800896) and -819/-592 (rs1800871/rs1800872) with HCC risk in individuals with HCV. The present study evaluated 388 chronic HCV patients. Polymorphisms were determined by real-time PCR. Diplotypes associated with low IL-10 production and the TNF-α GG genotype were significantly associated with HCC occurrence after multivariate logistic regression analysis (P = 0.027 and P = 0.029, respectively). Additionally, the IL-10 -819 (-592) TT (AA) genotype was significantly associated with multiple nodules and HCC severity according to BCLC staging (P = 0.044 and P = 0.025, respectively). Patients carrying low production haplotypes of IL-10 and the TNF-α GG genotype have higher risk to develop HCC. J. Med. Virol. 88:1587-1595, 2016. © 2016 Wiley Periodicals, Inc.

Mannose-binding lectin 2 (MBL2) gene polymorphisms do not influence frequency of infections in chronic lymphocytic leukemia patients.

BACKGROUND: Infectious complications represent the main cause of morbidity and mortality in chronic lymphocytic leukemia. It has been reported that polymorphisms of the mannosebinding lectin 2 (MBL2) genes are correlated with MBL protein serum levels and, consequently, are associated with the development of infectious diseases. OBJECTIVE: The purpose of this study was to investigate the possible association between MBL2 gene polymorphisms and risk of infection in chronic lymphocytic leukemia patients. METHODS: Peripheral blood samples from 116 chronic lymphocytic leukemia patients were collected; after genomic DNA extraction, real time polymerase chain reaction was used to determine the polymorphisms of the promoter region and exon 1 of the MBL2 gene. RESULTS: A high frequency of Binet stage A (p-value = 0.005) and absence of splenomegaly (p-value = 0.002) were observed in patients with no infection; however, variant alleles/ genotypes and haplotypes of this gene had no impact on the risk of infection. CONCLUSION: To the authors' knowledge, this is the first study describing the association between MBL2 polymorphisms and infectious disease in chronic lymphocytic leukemia. Although it was not possible to demonstrate any influence of MBL2 polymorphisms as a genetic modulator of infection in chronic lymphocytic leukemia, the authors believe that the present data are clinically relevant and provide the basis for future studies.

Mannose-binding lectin 2 (MBL2) gene polymorphisms do not influence frequency of infections in chronic lymphocytic leukemia patients

Background: Infectious complications represent the main cause of morbidity and mortality in chronic lymphocytic leukemia. It has been reported that polymorphisms of the mannosebinding lectin 2 (MBL2) genes are correlated with MBL protein serum levels and, consequently, are associated with the development of infectious diseases. Objective: The purpose of this study was to investigate the possible association between MBL2 gene polymorphisms and risk of infection in chronic lymphocytic leukemia patients. Methods: Peripheral blood samples from 116 chronic lymphocytic leukemia patients were collected; after genomic DNA extraction, real time polymerase chain reaction was used to determine the polymorphisms of the promoter region and exon 1 of the MBL2 gene. Results: A high frequency of Binet stage A (p-value = 0.005) and absence of splenomegaly (p-value = 0.002) were observed in patients with no infection; however, variant alleles/ genotypes and haplotypes of this gene had no impact on the risk of infection. Conclusion: To the authors' knowledge, this is the first study describing the association between MBL2 polymorphisms and infectious disease in chronic lymphocytic leukemia. Although it was not possible to demonstrate any influence of MBL2 polymorphisms as a genetic modulator of infection in chronic lymphocytic leukemia, the authors believe that the present data are clinically relevant and provide the basis for future studies. .

Mannose-binding lectin serum levels in patients with leprosy are influenced by age and MBL2 genotypes.

BACKGROUND: Mannose-binding lectin (MBL) activates the complement system promoting opsonophagocytosis, which could represent an advantage for Mycobacterium leprae, an intracellular pathogen. Therefore, a single nucleotide polymorphism (SNP) in the MBL2 gene associated with low levels of MBL could confer protection against the development of leprosy disease. METHODS: In this study, we investigated SNPs of the MBL2 gene and MBL levels in 228 Brazilian leprosy patients and 232 controls. RESULTS: There were no differences in the frequencies of variant genotypes and haplotypes of MBL2 between patients and controls, or between the different clinical forms of leprosy. In the group of patients with a genotype for high expression of MBL2, those aged>40 years had decreased MBL levels compared to patients aged ≤ 40 years (p = 0.037). CONCLUSION: Our results demonstrate that age could influence the phenotype of MBL2, but no evidence was found for an association of MBL2 polymorphism with susceptibility to leprosy or its clinical forms.