Peptide Microarrays for Flavivirus Diagnosis.

Flavivirus are the most alarming prevalent viruses worldwide due to its vast impact on public health. Most early symptoms of diseases caused by Flavivirus are similar among each other and to other febrile illnesses making the clinical differential diagnosis challenging. In addition, due to cross-reactivity and a relatively limited persistence of viral RNA in infected individuals, the current available diagnosis strategies fail to efficiently provide a differential viral identification. In this context, virus-specific tests are essential to improve patient care, as well as to facilitate disease surveillance and the effective control of transmission. Here, we describe the use of protein microarrays as an effective tool for screening peptides differentially recognized by anti-Yellow Fever virus antibodies induced by vaccination or by natural viral infection.

Mapping and Validation of Peptides Differentially Recognized by Antibodies from the Serum of Yellow Fever Virus-Infected or 17DD-Vaccinated Patients.

Yellow Fever disease is caused by the Yellow Fever virus (YFV), an arbovirus from the Flaviviridae family. The re-emergence of Yellow Fever (YF) was facilitated by the increasing urbanization of sylvatic areas, the wide distribution of the mosquito vector, and the low percentage of people immunized in the Americas, which caused severe outbreaks in recent years, with a high mortality rate. Therefore, serological approaches capable of discerning antibodies generated from the wild-type (YFV-WT) strain between the vaccinal strain (YFV-17DD) could facilitate vaccine coverage surveillance, enabling the development of strategies to avoid new outbreaks. In this study, peptides were designed and subjected to microarray procedures with sera collected from individuals infected by WT-YFV and 17DD-YFV of YFV during the Brazilian outbreak of YFV in 2017/2018. From 222 screened peptides, around ten could potentially integrate serological approaches aiming to differentiate vaccinated individuals from naturally infected individuals. Among those peptides, one was synthesized and validated through ELISA.

Mutation screening of TP53, CHEK2 and BRCA genes in patients at high risk for hereditary breast and ovarian cancer (HBOC) in Brazil.

BACKGROUND: Few studies related to hereditary breast and ovarian cancer syndrome (HBOC) have been conducted in Brazil, and they are restricted to only small areas of the country. Here, we report the mutation profile of BRCA1/2, CHEK2 and TP53 genes in a cohort from Minas Gerais state. METHODS: These genes from 44 patients at high risk for HBOC were screened through high-resolution melting and/or sequencing. The pathogenicity of the alterations was checked using ClinVar database and bioinformatics programs. RESULTS: In BRCA genes we identified 46 variants, 38 without clinical significance and 8 pathogenic mutations including a new pathogenic mutation in BRCA1 gene (c.4688_4694delACCTGGAinsG). The most prevalent pathogenic mutation was c.4829_4830delTG, in the BRCA2 gene. This mutation was not described in the Brazilian population up to now and in this study, it was described with a prevalence of 6.8%. The p.R337H mutation in TP53 gene was found in one patient clinically diagnosed as HBOC and without clinical criteria for Li-Fraumeni syndrome. In CHEK2 gene, the undescribed variant c.485A > G was found and it presents as probably pathogenic through in silico analyses. Pathogenic mutations were found in 29.5% of the patients, 11.3% in BRCA1, 15.9% in BRCA2 and 2.3% in TP53 gene. CONCLUSIONS: Brazilian population is one of the most heterogeneous in the world and the mutational profile knowledge of genes related to HBOC from different regions can contribute to the definition of more cost-effective strategies for the prevention, identification and treatment of cancer.

Screening of the BRCA1 gene in Brazilian patients with breast and/or ovarian cancer via high-resolution melting reaction analysis.

The aim of this study was to evaluate the profile of BRCA1 mutations among cancer-affected Brazilian women from the Midwest region of Minas Gerais state with clearly defined risk factors for hereditary breast and ovarian cancer (HBOC) syndrome. In this Brazilian region, the first Center for Hereditary Cancer Control began operation in 2011, and 90% of patients receive assistance from the public health service. Eighteen patients at high risk for HBOC were subjected to molecular analysis. Primers were designed for 22 coding exons of the gene; DNA was extracted; and real-time PCR followed by high-resolution melting reaction was performed. The amplicons were sequenced to confirm the identified profiles. Only exon 11 was directly sequenced due its length. Multiplex ligation-dependent probe amplification (MLPA) was performed for those patients in whom no pathogenic mutations were found. Among the 14 alterations identified in this study, the c.5263_5264insC pathogenic mutation was present in two patients (11.1%). Four alterations showed no clinical relevance; one exhibited inconclusive clinical relevance according to the examined databases; and eight alterations presented a divergent classification between the databases. No deletions or duplications were found using the MLPA technique. The HRM methodology was highly sensitive in identifying variants in the BRCA1 gene and can dramatically reduce the amount of sequencing required to identify germline mutations in BRCA genes, enabling cheaper tests and increasing their availability to Brazilian women assisted by the public health service.