HLA-DRB1 Polymorphisms and Rheumatologic Manifestations in Chronic Hepatitis C.

BACKGROUND/AIMS: Hepatitis C has been associated with rheumatologic manifestations (HCV-related RM). Clinically, HCV-related RM may be indistinguishable from the symptoms that occur in diffuse connective tissue diseases (DCTD-related RM), making the differential diagnosis difficult. Host genetic factors, such as the Human Leukocyte Antigens (HLA) polymorphisms were associated with HCV infection, however, there are no studies that discriminate between HCVrelated RM and DCTD-related RM. This study focused on verifying associations between HLADRB1 and RM in patients with chronic hepatitis C, aiming to distinguish between DCTD-related RM and HCV-related RM. METHODS: The participants were 152 individuals, of both sexes, aged between 18 and 80 years, and affected by chronic hepatitis C. The patients underwent rheumatologic physical examination and HLA-class II (HLA-DRB1) typing was performed by PCR-SSO (Polymerase Chain Reactionsequence Specific Oligonucleotides). RESULTS: A significant number of patients with rheumatologic complaints (73%) not attributed to other causes was observed. DRB1*08 allele seems to confer protection against RM in chronic hepatitis C. There is no susceptibility association between HLA-DRB1 alleles and RM. CONCLUSION: The absence of association between HLA-DRB1 and the rheumatologic manifestations studied suggests that the pathophysiological pathways of DCTD-related RM and HCV-related RM are distinct.

Influence of the HIV GWG variant in the HIV infection progression in mono and HCV coinfected patients.

The HIV subtype B is the most frequent in Brazil. The HIV subtype B' codes the amino acids glicine-tryptophan-glicine (GWG) instead of glicine-proline-glicine on the tip of gp120 V3 loop. This variant was associated to a slower HIV progression in mono-infected patients; however, there is no information in coinfected patients. This study evaluated the infection progression of HIV variant B' on the hepatitis C virus presence. RNA isolated from plasma of the 601 infected patients were used to human immunodeficiency virus (HIV) subtyping and to classify the virus according their syncytium-inducing ability. The HIV infection progression was evaluated by clinical and laboratorial data. The results showed a significant association between HIV B' variant and CD4 count and time of AIDS in HIV mono-infected patients. Notwithstanding the fact that we did not find a direct association between GWG variant and AIDS and in HIV coinfected patients no mitigating effect due to GWG presence was found. We did observe that the association between GWG variant and CD4 counts is lost in coinfected patients. This is first work showing influence of the HIV GWG variant in coinfected patients. Nevertheless, the presence of the GWG variant can indicate a better prognostic in the mono-infected patients.

HIV Reverse Transcriptase and Protease Genes Variability Can Be a Biomarker Associated with HIV and Hepatitis B or C Coinfection.

Variability of the HIV reverse transcriptase (RT) and protease (PR) genes has been used as indicators of drug resistance and as a mean to evaluate phylogenetic relationships among circulating virus. However, these studies have been carried in HIV mono-infected populations. The goal of this study was to evaluate, for the first time, the HIV PR and RT sequences from HIV/HBV and HIV/HCV co-infected patients. HIV PR and RT genes were amplificated and sequenced to resistance analysis. The bioinformatics analysis was performed to infer about sequences clustering and molecular evolution. The results showed that the most frequent amino acid substitutions in RT were L214F (67.6%), I135T (55.9%), and in PR was V15I (41.2%). The molecular clock analysis showed that the HIV circulating in co-infected patients were separated in two clusters in the years 1999-2000. Some patients included as HIV mono-infected according patients' medical records and inside the co-infected cluster were, in fact, co-infected by PCR analysis. Analysis of the decision trees showed susceptibility to lamivudine and emtricitabine were important attribute to characterize co-infected patients. In conclusion, the results obtained in this study suggest, for the first time, that HIV RT and PR genes variability could be a genetic biomarker to coinfection.

Hypermethylation of BRCA1 Gene in Meningioma in Elderly Males.

BACKGROUND/AIM: Breast cancer 1, early onset (BRCA1) gene is expressed in the cells of the breast and other tissues, where it plays a role in cell-cycle regulation, transcription, repair of DNA double-stranded breaks, ubiquitination, transcriptional regulation as well as other functions, such as cell response regulation to mitogenic signals triggered by estrogens. Considering that meningioma shows greater tumor growth during pregnancy, can express estrogen receptors and proliferate in response to estrogenic stimulation, the hypothesis that this type of tumor may share molecular mechanisms that involve exposure to estrogen should be investigated. Therefore, the aim of the present study was to investigate the BRCA1 gene methylation profile in meningioma. MATERIALS AND METHODS: Methylation-specific polymerase chain reaction (PCR) assay was performed on 50 meningioma samples from male and female patients. Statistical analysis was carried out using Fisher's exact test. RESULTS: The most important finding of this study was that 100% of the male patients over 55 years with meningioma showed BRCA1 methylated in their tumor cells. CONCLUSION: The silencing of BRCA1 through hypermethylation seems to play an important role in meningioma.

Influence of cytokine and cytokine receptor gene polymorphisms on the degree of liver damage in patients with chronic hepatitis C.

Hepatic fibrosis may be the result of repetitive injury to hepatocytes caused by HCV infection and the immune response to it. Cytokines regulate the inflammatory response to injury and modulate hepatic fibrogenesis. Single nucleotide polymorphisms (SNPs) located in cytokine genes may influence the cytokine expression and secretion that may contribute to hepatic fibrogenesis in HCV infection. The aim of this study was to determine the genotype of 22 SNPs found in the genes of 13 cytokines/cytokine receptors to assess the influence of polymorphic variants on the stage of liver damage in Brazilian patients chronically infected with HCV genotype 1 only. 141 unrelated patients were grouped according to their stage of fibrosis: absence of fibrosis or patients in the initial stages of fibrosis (F0-F2, n = 84), patients with advanced stages of fibrosis or cirrhosis (F3-F4, n = 57), without cirrhosis (F0-F3, n = 103), and with cirrhosis (F4, n = 38). The comparison of frequencies in each sub-sample was performed by 2 × 2 contingency tables using the chi-square or Fisher's exact test. Stepwise logistic regression was also used to assess independent associations between cirrhosis or fibrosis with polymorphic variants. The TNFA-308G:A genotype conferred increased risk of fibrosis and cirrhosis. The TNFA-238G:G genotype was associated with protection from cirrhosis. The IL10-819C:T genotype conferred protection from fibrosis and the IL1B-511C:T genotype conferred increased risk of cirrhosis. Some of these genotypes showed results on the borderline of statistical significance in the bivariate analysis. We conclude that gene variants of cytokines/receptors may influence liver damage in patients chronically infected by HCV genotype 1.

Inactivation of COX-2, HMLH1 and CDKN2A gene by promoter methylation in gastric cancer: relationship with histological subtype, tumor location and Helicobacter pylori genotype.

OBJECTIVE: We aimed to evaluate the inactivation of COX-2, HMLH1 and CDKN2A by promoter methylation and its relationship with the infection by different Helicobacter pylori strains in gastric cancer. METHODS: DNA extracted from 76 H. pylori-positive gastric tumor samples was available for promoter methylation identification by methylation-specific PCR and H. pylori subtyping by PCR. Immunohistochemistry was used to determine COX-2, p16(INK4A) and HMLH1 expression. RESULTS: A strong negative correlation was found between the expression of these markers and the presence of promoter methylation in their genes. Among cardia tumors, negativity of p16(INK4A) was a significant finding. On the other hand, in noncardia tumors, the histological subtypes had different gene expression patterns. In the intestinal subtype, a significant finding was HMLH1 inactivation by methylation, while in the diffuse subtype, CDKN2A inactivation by methylation was the significant finding. Tumors with methylated COX-2 and HMLH1 genes were associated with H. pylori vacA s1 (p = 0.025 and 0.047, respectively), and the nonmethylated tumors were associated with the presence of the gene flaA. CONCLUSIONS: These data suggest that the inactivation of these genes by methylation occurs by distinct pathways according to the histological subtype and tumor location and depends on the H. pylori genotype.

CDKN2A promoter methylation is related to the tumor location and histological subtype and associated with Helicobacter pylori flaA(+) strains in gastric adenocarcinomas.

Promoter hypermethylation of CDKN2A (p16INK4A protein) is the main mechanism of gene inactivation. However, its association with Helicobacter pylori infection is a controversial issue. Therefore, we examined a series of gastric adenocarcinomas to assess the association between p16INK4A inactivation and H. pylori genotype (vacA, cagA, cagE, virB11 and flaA) according to the location and histological subtype of the tumors. p16INK4A expression and CDKN2A promoter methylation were found in 77 gastric adenocarcinoma samples by immunohistochemistry and methylation-specific PCR, respectively. Helicobacter pylori infection and genotype were determined by PCR. A strong negative correlation between immunostaining and CDKN2A promoter region methylation was found. In diffuse subtype tumors, the inactivation of p16INK4A by promoter methylation was unique in noncardia tumors (p=0.022). In addition, H. pylori-bearing flaA was associated with non-methylation tumors (p=0.008) and H. pylori strain bearing cagA or vacAs1m1 genes but without flaA was associated with methylated tumors (p=0.022 and 0.003, respectively). Inactivation of p16INK4A in intestinal and diffuse subtypes showed distinct carcinogenic pathways, depending on the tumor location. Moreover, the process of methylation of the CDKN2A promoter seems to depend on the H. pylori genotype. The present data suggest that there is a differential influence and relevance of H. pylori genotype in gastric cancer development.