The relationship between IL-4 polymorphisms and asthma: a systematic review / A relação entre polimorfismos de IL-4 e asma: uma revisão sistemática

Asthma is a chronic and heterogeneous disease of the airways that begins in childhood and persists, in many cases, into adulthood. The disease is the result of environmental, epigenetic and genetic interactions. This work aims to review the polymorphisms described in the literature in the IL-4 gene associated with susceptibility or protection to the development of asthma. This is a systematic literature review, carried out in PubMed, MEDLINE and Science Direct databases in the time frame from 2000 to July 2021, revealing the following key points: IL-4, Polymorphisms and Asthma. The search resulted in 29 articles, all in English. Despite some divergent studies, the SNP rs2243250, which was the most studied in populations from different countries, was also the one that found the most correlations of susceptibility with the disease. It is concluded that although there is controversial data on IL-4 SNPs related to the disease, the association of pangenomic studies has brought a list of genes and their variations associated with the risk of developing asthma, such as the rs2243250 SNP that was well related in populations of several countries analyzed. (AU)

A asma é uma doença crônica e heterogênea das vias aéreas que tem início na infância e persiste em muitos casos até a vida adulta. A doença é resultado de interações ambientais, epigenéticas e genéticas. Este trabalho tem como objetivo revisar sobre os polimorfismos descritos na literatura no gene IL-4 associados à susceptibilidade ou proteção ao desenvolvimento da asma. Trata-se de uma revisão sistemática da literatura, feita nos bancos de dados PubMed, MEDLINE e Science Direct no corte temporal de 2000 a julho de 2021, ressaltando os seguintes pontos-chave: IL-4, Polimorfismos e Asma. A pesquisa resultou em 29 artigos, sendo em sua totalidade em língua inglesa. Apesar de alguns estudos divergentes, o SNP rs2243250, que foi o mais estudado em populações de diversos países, também foi o que mais encontrou correlações de susceptibilidade com a doença. Conclui-se que, apesar de haver dados controversos sobre os SNPs de IL-4 relacionados à doença, a associação dos estudos pangenômicos tem trazido uma lista de genes e variações deles associados com o risco de desenvolver a asma, como o SNP rs2243250 que foi bem relacionado em populações de vários países analisados (AU).

Toll-like receptor 3 gene polymorphisms are not associated with the risk of hepatitis B and hepatitis C virus infection

INTRODUCTION: The present study investigated the prevalence of two single-nucleotide polymorphisms (SNPs) in the Toll-like receptor 3 (TLR3) gene in patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV). METHODS: Samples collected from HCV (n = 74) and HBV (n = 35) carriers were subjected to quantitative real-time PCR (qPCR) to detect the presence of the SNPs rs5743305 and rs3775291 in TLR3 and to measure the following biomarkers: alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), and prothrombin time (PT). A healthy control group was investigated and consisted of 299 HCV- and HBV-seronegative individuals. RESULTS: No significant differences in allele, genotype and haplotype frequencies were observed between the investigated groups, and no association was observed between the polymorphisms and histopathological results. Nevertheless, genotypes TA/AA (rs5743305) and GG (rs3775291) appear to be associated with higher levels of ALT (p<0.01), AST (p<0.05) and PT (p<0.05). In addition, genotypes TT (rs5743305; p<0.05) and GG (rs3775291; p<0.05) were associated with higher GGT levels. CONCLUSIONS: This genetic analysis revealed the absence of an association between the polymorphisms investigated and susceptibility to HBV and HCV infection; however, these polymorphisms might be associated with a greater degree of biliary damage during the course of HCV infection. .

JC polyomavirus infection in candidates for kidney transplantation living in the Brazilian Amazon Region

This study evaluated the relative occurrences of BK virus (BKV) and JC virus (JCV) infections in patients with chronic kidney disease (CKD). Urine samples were analysed from CKD patients and from 99 patients without CKD as a control. A total of 100 urine samples were analysed from the experimental (CKD patients) group and 99 from the control group. Following DNA extraction, polymerase chain reaction (PCR) was used to amplify a 173 bp region of the gene encoding the T antigen of the BKV and JCV. JCV and BKV infections were differentiated based on the enzymatic digestion of the amplified products using BamHI endonuclease. The results indicated that none of the patients in either group was infected with the BKV, whereas 11.1% (11/99) of the control group subjects and 4% (4/100) of the kidney patients were infected with the JCV. High levels of urea in the excreted urine, low urinary cellularity, reduced bladder washout and a delay in analysing the samples may have contributed to the low prevalence of infection. The results indicate that there is a need to increase the sensitivity of assays used to detect viruses in patients with CDK, especially given that polyomavirus infections, especially BKV, can lead to a loss of kidney function following transplantation.