Maria Tereza Cartaxo Muniz

High tumor necrosis factor-α/interleukin-10 ratio is associated with hepatocellular carcinoma in patients with chronic hepatitis C.

Hepatitis C virus (HCV) is the main cause of chronic liver disease, cirrhosis and hepatocellular carcinoma (HCC) worldwide. The risk for the development of HCC increases with the severity of liver inflammation and fibrosis. The hepatic inflammation caused by HCV involves host regulatory immune response, which is mediated by cytokines with anti-viral role upon the interaction of viral polypeptides with innate and adaptive immunity. Two cytokines; tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) play key roles in the regulation of cellular immune response in HCV infection. The aim of the present study was to determine the levels of IL-10 and TNF-α, as well as the ratio of TNF-α and IL-10 serum levels in patients with HCV and HCC caused by HCV (HCC-HCV). The study included 173 patients with chronic HCV. TNF-α and IL-10 serum levels were measured by ELISA (R&D Systems, Inc.). In the present study, 54 patients presented liver mild fibrosis, 68 had severe fibrosis and 51 patients had HCC. After adjustment in the multivariate regression analysis, the following variables remained significantly associated with HCC-HCV occurrence: diabetes (p=0.012 OR 10.44 CI 1.66-65.60), IL-10 lower levels (p<0.0001 OR 0.83 CI 0.78-0.89) and TNF-α higher levels (p<0.0001 OR 1.19 CI 1.11-1.28). Individuals with HCC presented higher TNF-α/IL-10 ratio than those with fibrosis grade F4, F3 or F0+F1+F2 (p=0.0003, p<0.0001, p<0.0001, respectively). Patients with HCC were associated to higher index TNF-α/IL-10 ratio, suggesting that the unbalanced production of these cytokines may represent progression to the liver disease severity in HCV infected patients.

Association between the MTHFR A1298C polymorphism and increased risk of acute myeloid leukemia in Brazilian children

Methylenetetrahydrofolate reductase (MTHFR) is an essential enzyme in the metabolism of folate. The presence of polymorphisms that reduce the activity of MTHFR has been linked to the multifactor process of development of acute leukemia. A case control study was conducted on Brazilian children in different regions of the country with the aim of investigating the role of MTHFR C677T and A1298C polymorphisms as risk factors in the development of acute myeloid leukemia (AML). We used the polymerase chain reaction restriction fragment length polymorphism method to genotyping 182 AML and 315 healthy individuals. The genotype 677 CT was associated with decreased risk [odds ratio (OR), 0.37; confidence interval (CI) 95%, 0.14 – 0.92], whereas 1298 AC genotype was linked with an increased risk [OR, 2.90; CI 95%, 1.26 – 6.71] of developing AML in non-white children. Further epidemiological study is needed to unravel the complex multiple gene-environment interactions in the role of the AML leukemogenesis.

Influence of Methylenetetrahydrofolate Reductase C677T, A1298C, and G80A Polymorphisms on the Survival of Pediatric Patients with Acute Lymphoblastic Leukemia.

The influence of genic polymorphisms involved in metabolism of chemotherapeutic agents as the methotrexate (MTX) has been studied mainly in acute lymphoblastic leukemia (ALL) of childhood. Advances in treatment may be attributed to identification of prognostic factors added to chemotherapy protocol. The aim of this study was to analyze the association of the C677T, A1298C, and G80A polymorphisms on MTHFR gene and on the overall survival of pediatric patients (n = 126) with lymphoblastic leukemia treated with MTX according to the Brazilian protocol in 187 months. The C677T and G80A polymorphisms were genotyped by PCR-RFLP and A1298C polymorphism by allele-specific PCR. We observed that ALL patients presented rate (dead/alive) of 0.36 for the 677CC genotype, corresponding also to lower overall survival (P = 0.0013); on the other hand, the 677TT genotype showed a better survival (98%). Thus, we believe that patients with 80AA genotype presented a small reduction in MTX plasma level, suggesting that ALL children, carrying the 80AA genotype, showed a high toxicity to MTX (P < 0.0001).

Polymorphisms Involved in Folate Metabolism Pathways and the Risk of the Development of Childhood Acute Leukemia

OBJECTIVE Polymorphisms that reduce the activity of reduced folate carrier (RFC) and methylenetetrahydrofolate reductase (MTHFR) and double (2R2R) or triple (3R3R) 28-bp tandem repeats in the promoter region of thymidylate synthase (TS) have been associated with the risk of childhood acute leukemia (AL). A case-control genotyping study was conducted in Brazilian children with the aim of investigating RFC, MTHFR, and TS polymorphisms as risk factors. METHODS The polymerase chain reaction-restriction fragment length polymorphism method was employed in 177 AL cases and 390 controls. RESULTS The presence of the mutant 1298C, also RFC 80A, was linked to a decreased risk of developing acute lymphoid leukemia (ALL) (odds ratio (OR)=0.46, 95% confidence interval (CI)=0.30-071 and OR=0.51, 95% CI=0.28-0.0.93, respectively). CONCLUSIONS The genotype 677 CT was associated with increased risk of developing ALL (OR=1.6, 95% CI=1.1-2.7). Further epidemiological study is needed to unravel the role of complex multiple gene-environment interactions in leukemogenesis.

Tumor necrosis factor alpha promoter polymorphism -308 G/A in Brazilian patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the production of antibodies to components of the cell nucleus in association with a diverse array of clinical manifestations. Polymorphisms in cytokines genes may play an important role in the development and clinical manifestation. Due to this, there is a great interest in the identification of biomarkers that which could quantify the susceptibility and disease activity. A case-control study of 98 lupus cases and 76 lupus-free adults controls, was performed to analyze whether or not the polymorphism of the TNF-α gene promoter at positions -308 G/A would alter the risk for SLE and clinical manifestations. Genotyping was carried out by polymerase chain reaction, PCR products were digested by NcoI restriction enzyme and fractionated after on 2% Agarose gel and visualized posteriorly staining by ethidium bromide. There were significant differences in the distribution of the TNF-α gene polymorphism between the SLE and control groups. Individual carriers of the variant allele A had a 3.29 (95% CI: 1.7738-6.1325)-fold increased risk for SLE. Moreover, association was observed between SLE patients and serositis (P=0.0228). This study presents a preliminary evidence of association between TNF-α polymorphism and SLE susceptibility in the Northeast population from Brazil.

MTR polymorphic variant A2756G and retinoblastoma risk in Brazilian children

Polymorphisms in the genes of folate and methionine metabolism enzymes have been associated with some forms of cancer by affecting DNA synthesis, repair, and methylation.

Avaliação da relação entre o polimorfismo C677T no gene para MTHFR e a concentração plasmática de homocisteína na doença arterial coronariana

OBJECTIVE: The aim of this study is to determine the prevalence of C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism and correlate it with plasma homocysteine levels in coronary artery disease (CAD). METHODS: Ninety-three patients with documented CAD from Hospital Universitario Oswaldo Cruz (Recife, PE, Brazil) and 108 healthy controls were evaluated. Homocysteine and folate levels were determined by HPLC and chemoluminescence, respectively, and lipid profile was considered. Genotyping was done by RFLP/PCR. RESULTS: The groups were homogeneous for the C677T polymorphisms. The homocysteine level in cases (11.7 µmol/L) was statistically different from that observed in controls (8.84 µmol/L, p< 0.05). It was also observed that 72% of the patients had homocysteine values above12 µmol/L while the control group presented only 32% in this range. There was no relationship between homozigosity for the C677T polymorphism and the homocysteine level (p= 0.634). We noticed statistical differences between folate levels from patients and controls (6.22 and 7.69 ng/dL, p< 0.05, respectively). However, there was no correlation between homocysteine and folate concentrations in the entire group (r= -0.202). Comparing cases and controls, the odds ratio (OR) when homocysteine is high and folate is low was OR= 11.9; CI 95%= 4.16-34.42, p< 0.01. CONCLUSION: A lack of correlation between C677T mutation and homocysteine level suggests that environmental factors and others genetic factors seem to exert more influence on homocysteine level in this population.

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.

Prevalence and Genetic Variability in Capsid L1 Gene of Rare Human Papillomaviruses (HPV) Found in Cervical Lesions of Women from North-East Brazil

The aim of this study was to examine the prevalence and genetic variability of the capsid L1 gene of rare HPV genotypes that were found in the cervical lesions of women from North-East Brazil. A total number of 263 patients were included in this study. HPV detection was performed using PCR followed by direct sequencing of MY09/11, as well as type-specific PCR to detect the Alpha-9 species. Epitope prediction was performed to determine whether or not the genetic variants are inserted in B-cell and T-cell epitopes. The prevalence of rare HPV types in cervical lesions was found to be 9.47%. The rare HPV genotypes that were detected were HPV-53, 54, 56, 61, 62, 66, 70, and 81. The genetic variability in the L1 gene of rare HPV types involved thirty nucleotide changes, eight of which were detected for the first time in this study. Moreover, some of these variants are embedded in B-cell or T-cell epitope regions. The results of this research suggest that rare HPV types might be involved in cervical lesions and some of these variants can be found in B-cell and T-cell epitopes. Data on the prevalence and variability of rare HPV types will assist in clarifying the role of these viruses in carcinogenesis.

Fatores prognósticos em crianças e adolescentes com Leucemia Linfóide Aguda

OBJETIVES: to describe the clinical and laboratory characteristics, determine rates of response to treatment and pinpoint risk factors that influence the survival of pediatric patients with acute lymphoblastic leukemia (ALL). METHODS: this is a retrospective series of case studies involving 108 patients aged 18 years or under hospitalized for ALL treatment at the Fundacao de Hematologia e Hemoterapia de Pernambuco (HEMOPE), Brazil, between January 1993 and December 2001. The following variables were analyzed: gender, age, main symptoms and signs, white blood-cell count, immunophenotype and risk group on diagnosis; rates of remission and relapse, death and overall survival; place of relapse and risk factors for survival. Descriptive measurements were used for the statistical analysis. The patient survival time was estimated using the Kaplan-Meier survival function and Log Rank. The effect of risk factors on survival time was evaluated using the Cox Regression Model. RESULTS: the results showed a male:female ratio of 1.7:1, a median age of eight years on diagnosis, the frequency of musculoskeletal complaints was 51%, of infiltration of the central nervous system 8%, of ALL-Precursor B 81% and ALL-T 19%. The distribution of the groups corresponded to True Basic Risk (12%), Basic Risk (21%) and High Risk (67%). The rates of remission, relapse and overall survival were 86%, 24% and 62.5%, respectively. CONCLUSIONS: the variable having an impact on overall survival was the white blood-cell count. The overall survival rate in the study was influenced by the high frequency of high-risk patients.