RELAÇÃO MATERNO-INFANTIL NA RESPOSTA IMUNOLÓGICA E O DESENVOLVIMENTO DA SÍNDROME DA ZIKA CONGÊNITA

Abstract

Zika virus is an arbovirus that has gained great importance in public health because maternal infection by this virus during pregnancy is responsible for development of a series of fetal malformations, called Congenital Zika Syndrome (CZS). The pathological processes involved in the development of CZS have not yet been well established, but it is known that there is an important role of immune mechanisms in susceptibility and evolution of the syndrome. Children who presented the clinical phenotype of CZS at birth participated in the study. Based on the imaging exams, where the presence of calcifications, reduced parenchymal volume, ventriculomegaly and cortical malformations were evaluated, the clinical manifestations were classified as mild, moderate and severe. Thus, the study correlated the immunological profile of the syndromic children with that of their respective mothers, as well as the oxidative response markers of both. For this purpose, blood samples were collected from children with CZS, confirmed by means of the Plaque Reduction Neutralization Test (PRNT), and from their mothers, as well as from children who did not develop the syndrome and were negative for the neutralization test, and from their mothers. From the blood samples, immunophenotyping of blood leukocytes, dosage of cytokines and evaluation of redox response parameters were performed. We observed that the immune response profile between mothers and PRNT+ children is correlated, both have increased interleukin (IL)- 17 and monocytes, which probably have an M1 phenotype, due to increased oxidative response, which was perceived by increased production of hydrogen peroxide, and also due to decreased activity of plasma arginase enzyme. In addition to the increased inflammatory profile, mothers and children showed a decrease in the CD4 T lymphocyte subpopulation and, specifically, mothers had a decrease in the expression of HLA molecules on the surface of monocytes. Thus, we can notice a reduction in regulatory mechanisms, contributing to the establishment of a more inflammatory response. It was also observed that children with greater clinical severity showed increased concentrations of IL-17, as well as their mothers showed higher concentrations of IL-17 and IL-6. Through these results we can suggest that the development of SZC may be related to an immune-inflammatory profile characterized by both an increase in inflammatory components and a reduction in regulatory mechanisms. And probably, the greater severity of malformations caused by intrauterine infection by Zika virus may be related to maternal immune activation induced by Th17 response profile.