Revisiting the metallothionein genes polymorphisms and the risk of oral squamous cell carcinoma in a Brazilian population.

BACKGROUND: Metallothioneins (MTs) gene polymorphisms have been associated with the ability of free radical scavenging and detoxification of heavy metals leading to cancer development. Our aim was to revisit, in a Brazilian population, single-nucleotide polymorphisms (SNPs) of the MT gene family previously associated with oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: A case-control investigation with 28 OSCC patients and 45 controls was conducted, using conventional risk factors (tobacco use and alcohol consumption) as covariates. SNPs genotyping for rs8052334 (MT1B), rs964372 (MT1B), and rs1610216 (MT2A) was performed by PCR-RFLP, and SNPs for rs11076161 (MT1A) were analyzed by TaqMan assay. RESULTS: The only SNP associated with increased risk for OSCC was the MT-1A AA genotype (OR = 4.7; p = 0.01). We have also evidenced for the first time a significant linkage disequilibrium between the SNPs of MT-2A and MT-1A in this population with the highest frequency (30%) of the unfavorable haplotype G/A/C/T (rs1610216 / rs11076161 / rs964372 / rs8052334) of MT gene polymorphisms (OR = 6.2; p = 0.04). Interestingly, after removing the effects of conventional risk factors, we have uncovered the significance of the AA genotype of the rs11076161 with increased odds of 19-fold higher towards OSCC development. CONCLUSIONS: This is the first demonstration that a significant linkage disequilibrium among gene polymorphisms of the MT family may affect susceptibility to oral cancer, which is conditioned by the G/A/C/T haplotype (rs1610216/rs11076161/rs964372/ rs8052334) and the MT-1A gene polymorphism has a potential clinical utility for the OSCC risk assessment.

Effectiveness and Adverse Events of Use of Natalizumab in a Brazilian Cohort of Patients With Multiple Sclerosis.

PURPOSE: Natalizumab (NTZ) is a monoclonal antibody with confirmed efficacy in white populations with recurrent-remitting multiple sclerosis (RRMS); there are few studies, however, in mixed-race populations. Real-world studies of NTZ are needed to better understand the drug's effectiveness. This study evaluated the effectiveness and adverse events of NTZ in a cohort of Brazilian patients with MS, as well as the impact of clinical and demographic factors on patient response to treatment. METHODS: This multicenter, Brazilian observational study was conducted from January 2011 until December 2016 and included patients with RRMS (McDonald criteria 2005 and 2010) aged ≥18 years treated with NTZ for at least 3 months. Demographic, clinical, and radiologic data were obtained from medical records and during follow-up visits. The primary outcomes investigated were the absolute number of relapses and annualized rate of relapses, change in Expanded Disability Status Scale value, and presence of new lesions on magnetic resonance imaging after starting NTZ treatment; the occurrence and type of adverse events were also analyzed. In addition, the impact of demographic and clinical prognostic factors and radiologic activity on the effectiveness of NTZ was measured. Descriptive and univariate statistical analyses used a significance level of P < 0.05. RESULTS: The study enrolled 56 patients; 64% were women, and 36% were of African descent. There was a significant reduction in the mean absolute number (P = 0.001) and in the annualized rate (P = 0.001) of relapses and in the radiologic activity of the disease (P = 0.001). Furthermore, 71% of patients showed no increase in Expanded Disability Status Scale score after 1 year of treatment. The effectiveness of NTZ was not associated with the presence of clinical and demographic prognostic factors, and the most frequent adverse events during the use of NTZ were gastrointestinal symptoms; there were no cases of progressive multifocal leukoencephalopathy. IMPLICATIONS: According to patients' reports and clinicians' observations regarding clinical and radiologic benefits and tolerability to adverse events, the use of NTZ was favorable in this Brazilian MS cohort, regardless of the presence of unfavorable prognostic factors.