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.

Molecular profile of mannan-binding lectin in hepatitis C patients with MBL gene polymorphisms by a modified mannan-coated nitrocellulose assay.

The aim of this study was to develop an assay to analyze the serum profile of Mannose-binding lectin (MBL) through a simple and "in-house" method (called "dot-N-man"). Furthermore, the study attempted to associate molecular masses of MBL to the profile of MBL gene polymorphisms in patients with hepatitis C. Heterogeneity in molecular masses of MBL is due to the impairment of oligomers formation, which is linked to genetic polymorphisms in the MBL gene. Individuals with AA genotype (wild-type) produce high-molecular-mass proteins, whereas AO and OO individuals produce intermediate and low-molecular-mass proteins, respectively. Sera of thirty patients carrying the hepatitis C virus (HCV) were investigated using MBL binding assay with mannan-coated nitrocellulose (dot-N-man). Purified MBL was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Dot-N-Man assay yielded MBL with molecular masses ranging between 55 and 320 kDa, comparable to low and high molecular mass forms of MBL. Nonreducing SDS-PAGE showed high molecular mass bands in all AA individuals while bands of 270 and 205 kDa were observed in sera for a number of patients with AO and OO genotypes, respectively. Immunoblotting confirmed the MBL samples obtained from the dot-N-man. These results provide new insights to understand the MBL molecular forms profile in patients infected with HCV- which could be useful in future investigations on the influence of the MBL structure/genotype on both the progression of infection and the response to hepatitis C therapy.

Role of Interleukin-22 in chronic liver injury.

Liver fibrosis is the result of an exacerbated wound-healing response associated with chronic liver injury. Advanced liver fibrosis results in cirrhosis, liver failure, and portal hypertension and frequently requires liver transplantation. The host immune response has an important role driving fibrosis deposition by activating hepatic stellate cells (HSCs). Interleukin-22 (IL-22) is a cytokine that plays a key role in promoting antimicrobial immunity and tissue repair at barrier surfaces. Data from literature suggest that IL-22 has a protective role in the liver by reducing fibrosis in some pathological conditions, however the results are contradictory. This review highlights current knowledge of IL-22' role in chronic liver injury, as well as its therapeutic potential for the treatment of chronic liver injury.

Association of Catalase and Glutathione Peroxidase 1 Polymorphisms with Chronic Hepatitis C Outcome.

The hepatic damage caused by hepatitis C virus (HCV) infection is associated with the host immune response and viral regulatory factors. Catalase (CAT) and glutathione peroxidase 1 (GPX1) are antioxidant enzymes located in the peroxisomes and mitochondria, respectively, and are responsible for the control of intracellular hydrogen peroxide levels. Polymorphisms in CAT (C-262T) and GPX1 (Pro198Leu) are correlated with serum levels and enzyme activity. This study aimed to investigate the association of genetic polymorphisms of CAT C-262T (rs1001179) and GPX1 Pro198Leu (rs1050450) with different stages of liver fibrosis and development of hepatocellular carcinoma (HCC). This study included 445 patients with chronic hepatitis C, of whom 139 patients had mild fibrosis (F0-F1), 200 had moderate/severe fibrosis (F2-F4), and 106 had HCC. Genotyping of SNPs was performed by real-time PCR using TaqMan probes. The Pro/Pro genotype of GPX1 was significantly associated with fibrosis severity, HCC, Child Pugh score, and BCLC staging. Additionally, patients carrying both CT+TT genotypes in the CAT gene and the Pro/Pro genotype in the GPX1 gene had higher risk for developing moderate/severe fibrosis or HCC (p = 0.009, OR 2.40 and p = 0.002, OR 3.56, respectively). CAT and GPX1 polymorphisms may be implicated in the severity of liver fibrosis and HCC caused by HCV.

[Association between serum markers for celiac and thyroid autoimmune diseases]. / Associação entre marcadores sorológicos de doença celíaca e das doenças autoimunes da tireóide.

Celiac disease (CD) is an autoimmune disease of the small bowel characterized by a strong genetic association with HLA - DQ2 and DQ8. Gluten is the etiological factor and the tissue enzyme transglutaminase (TGase) is its autoantigen. CD is associated with several autoimmune diseases such as type 1 diabetes, systemic lupus erythematous, rheumatoid arthritis, Sjögrens syndrome and autoimmune thyroid diseases. The aim of this study was to investigate the occurrence of serum IgA anti-endomysial and anti-human TGase antibodies in individuals with positive anti-thyroid antibody (ATA). The concordance between these two tests was also evaluated. Anti-endomysial antibodies were positive in 10 out of 456 (2.2%) and anti-human TGase were positive in 14 of 454 (3.1%) individuals with positive ATA. In control subjects they were positive in 1 of 197 (0.5%) and 2 of 198 (1%) for anti-endomysial and anti-human tissue TGase antibodies, respectively. The odds ratio (OR) for the anti-endomysial antibodies was 4.42 and for the anti-human TGase 3.12 in individuals with ATA when compared with controls. An elevated concordance index (k= 0.84) was observed between anti-endomisyal antibodies and anti-human TGase. We conclude that the determination of anti-TGase antibodies is a good test for DC screening.

Associação entre marcadores sorológicos de doença celíaca e das doenças autoimunes da tireóide / Association between serum markers for celiac and thyroid autoimmune diseases

Doença celíaca (DC) é uma doença autoimune do intestino delgado com importante associação com HLA-DQ2 e DQ8. Tem o glúten como fator etiológico e a enzima transglutaminase (TGase) tecidual como autoantígeno. A DC é associada a outras doenças autoimunes como diabetes mellitus tipo 1, lupus eritematoso sistêmico, artrite reumatóide, síndrome de Sjõgren e doenças autoimunes da tireóide. O objetivo deste estudo foi investigar a ocorrência de anticorpos séricos da classe IgA anti-endomísio e anti-TGase tecidual humana em indivíduos com anticorpo anti-tireoidiano (AAT) positivo. Foi também pesquisada a concordância destes dois marcadores. Anticorpos anti-endomísio foram positivos em 10 de 456 (2,2 por cento) e anti-TGase tecidual foi positiva em 14 de 454 (3,1 por cento) dos indivíduos com AAT positivo. No grupo controle, 1 de 197 (0,5 por cento) e 2 de 198 (1 por cento) foram positivos para anticorpo anti-endomísio e anti-TGase tecidual humana, respectivamente. A chance de positividade dos anticorpos anti-endomísio foi de 4,42 e do anti-TGase tecidual humana 3,12 vezes maior nos indivíduos com positividade para AAT que nos controles. Um elevado índice de concordância (k= 0,84) foi obtido entre os testes para anticorpos anti-endomísio e anti-TGase. Os resultados obtidos neste trabalho não justificam uma triagem rotineira de DC em portadores de AAT. Concluímos que a pesquisa de anticorpos anti-TGase mostrou-se um teste útil para rastrear DC.

Chronic hepatitis C infection: influence of the viral load, genotypes, and GBV-C/HGV coinfection on the severity of the disease in a Brazilian population.

The distributions of the different genotypes of the hepatitis C virus (HCV) and GBV-C virus (GBV-C/HGV) vary geographically and information worldwide is still incomplete. In particular, there are few data on the distribution of genotypes (and their relationship to the severity of liver disease) in South America. Findings are described in 114 consecutive patients from Northeast Brazil (median age 52 years, range 18-72 years) who had abnormal levels of serum aminotransferases and seropositivity for HCV RNA. The patients were recruited from an outpatient clinic between November 1997 and April 1998. Quantitative HCV RNA and GBV-C/HGV RNA estimations were carried out by double-nested polymerase chain reaction (PCR) using primers from the 5'-untranslated regions (UTRs) of the genomes. HCV genotypes were determined by restriction fragment length polymorphism (RFLP) analysis with 5'-UTR primers and by PCR with type-specific 5'-UTR primers. GBV-C/HGV-RNA genotypes were determined by RFLP with specific 5'-UTR primers and phylogenetic trees were constructed using the Neighbour-Joining and Drawtree programs. Histological features were graded and staged according to international criteria. Of the 114 patients, 35 (30.7%) patients had cirrhosis and 22 (27.8%) had mild, 51 (64.6%) had moderate, and 6 (7.6%) had severe chronic hepatitis. Median HCV viral load was 10(6) genome equivalents per millilitre (range 10(4)-10(9)/ml). Frequencies of genotypes were 5.3% type 1a, 44.7% type 1b, 3.5% type 2, 41.2% type 3, and 5.3% mixed types. GBV-C/HGV-RNA was detected in the sera of 12 (10.5%) patients and was distributed among three phylogenetic groups. There were no significant differences between patients with the predominant HCV genotypes (1b and 3) with respect to gender, age group, viral load, severity of liver disease, or coinfection with GBV-C/HGV.