Frequência do polimorfismo de nucleotídeo único (SNP) rs12979860 no gene IFN-λ3 entre gestantes com complicações obstétricas infectadas pelos vírus Zika e chikungunya e repercussões neonatais

Abstract

Zika (ZIKV) and chikungunya virus (CHIKV) infections during pregnancy have been related to adverse clinical outcomes in the mother or her fetus. Single Nucleotide Polymorphisms (SNPs), with locus in immune response genes, may be involved in the occurrence of these complications. Thus, this study aimed to describe the frequency of SNP rs12979860 (C/T) in IFN-λ3 gene among pregnant/parturient women with obstetric complications attributed or not to Zika and chikungunya fever and to evaluate neonatal repercussions. For this purpose, we compared the genotypic and allelic frequencies of rs12979860 between two women groups with obstetric complications: infected with ZIKV or CHIKV (n=122) and non-infected (n=212). Then, we related the presence of neonatal complication (n=167) and absence of neonatal complication (n=166) with the presence of maternal infection and the SNP. To identify the SNP, we performed genotyping analysis using DNA extracted from blood samples with Wizard Genomic DNA Purification kit (PROMEGA, USA). Assays were accomplished by qPCR using a TaqMan fluorescent probe system. Differences between groups were analyzed using Pearson's chi-square test (X2) at a significance level p<0.05. We employed genotypic, recessive and dominant models to test associations of genotypes. All SNPs were in Hardy-Weinberg equilibrium. In the infected pregnant women/parturients group, the frequencies of TT, CT, and CC genotypes were 18.9%, 40.1%, 41.0%, respectively. In the non-infected group, these values were 19.8%, 47.6%, 32.5%, respectively. No significant difference was observed for the association between genotypic and allelic frequencies and the acquisition of infection by ZIKV and CHIKV in pregnant women with obstetric complications. Our results point to an association between maternal CT/TT genotypes and the risk of neonatal complications (p= 0.010), although the presence of maternal arboviral infection was not associated with this outcome (p= 0.076). It is concluded, although the presence of SNP rs12979860 in pregnant women with obstetric complications was not related to the acquisition of infections by ZIKV and CHIKV and presence of infection in the mother was not related to the development of neonatal complications, the CT/TT profile maternal is a risk predictor for complications in neonates.