HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil.

BACKGROUND: Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil. OBJECTIVE: To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence. METHODS: A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients. RESULTS: The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each. CONCLUSIONS: These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil

ABSTRACT Background Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil. Objective To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence. Methods A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients. Results The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each. Conclusions These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

Genomic and in silico analyses of CRBN gene and thalidomide embryopathy in humans.

Thalidomide causes Thalidomide Embryopathy (TE), but is largely used to treat several conditions. Investigations with Cereblon, a thalidomide target protein encoded by CRBN gene, have helped to understand thalidomide therapeutic and teratogenic properties. We sequenced CRBN-thalidomide binding region in 38 TE individuals and 136 Brazilians without congenital anomalies, and performed in silico analyses. Eight variants were identified, seven intronic and one in 3'UTR. TE individuals had rare variants in higher frequency than the non-affected group (p=0.04). The genotype rs1620675 CC was related to neurological anomalies in TE individuals (p=0.004). Bioinformatics analysis suggested this genotype leads to potential alterations in splicing sites and binding to transcription factors. Comparison of the Cereblon-thalidomide binding domains in mammals demonstrated that CRBN is highly conserved across species. All the variants require evaluation in functional assays in order to understand their role in Cereblon-thalidomide binding and complex interactions that lead to TE.

Lack of association between thrombophilic gene variants and recurrent pregnancy loss.

Recurrent pregnancy loss (RPL) is defined as the occurrence of two or more consecutive pregnancy losses. It is an important reproductive condition with a complex etiology. In approximately 50% of RPL cases an explanation for the cause is not found and they are therefore classified as idiopathic RPL. One of the causes implicated in RPL is thrombophilia, which consists of hemostatic disorders that lead to an increase in thromboembolic processes. The aim of this study was to evaluate polymorphic variants in genes related to thrombophilia as a risk factor in women with RPL. We investigated 145 women with at least two consecutive pregnancy losses and 135 women with at least two children and no history of pregnancy loss. Genotypes for the polymorphisms MTHFR C677T, FVL, FII (prothrombin), eNOS T-786C, and eNOS Glu298Asp were determined using a real-time PCR. Information about the exposure to environmental risk factors was also collected. There was no significant association between the environmental risk factors assessed and the polymorphisms studied. We did not find statistically significant differences in genotypic or allelic frequencies for the polymorphisms studied, in either the women with RPL or in the control group. Such polymorphisms should therefore not be considered as risk factors for this condition in this population.