Utilização de ácidos nucleicos fetais livres no plasma materno para o diagnóstico pré-natal: realidade do Brasil neste cenário / Use of cell-free fetal nucleic acids in maternal blood for prenatal diagnosis: the reality of this scenario in Brazil

A descoberta de ácidos nucleicos fetais livres no plasma de gestantes possibilitou o desenvolvimento de novos testes de diagnóstico pré-natal não invasivo para a determinação do sexo e do Rh fetal. Esses testes foram implantados no sistema de saúde pública de diversos países da Europa há mais de cinco anos. As novas possibilidades de aplicação diagnóstica dessas tecnologias são a detecção de aneuploidias cromossômicas fetais, de doenças monogênicas fetais e de distúrbios relacionados com a placenta, temas pesquisados intensivamente por diversos grupos ao redor do mundo. O objetivo deste estudo é expor a situação brasileira no âmbito de pesquisa e utilização clínica dos testes disponíveis comercialmente que utilizam esses marcadores moleculares plasmáticos, ressaltando as vantagens, tanto econômicas quanto de segurança, que os testes não invasivos têm em relação aos atualmente utilizados em nosso sistema de saúde pública.

The discovery of cell-free fetal nucleic acids in the plasma of pregnant women has allowed the development of new, noninvasive prenatal diagnostic tests for the determination of fetal gender and Rh. These tests have been implemented in the public health system in several countries of Europe for over five years. The new possibilities for diagnostic use of these technologies are the detection of fetal chromosomal aneuploidies, monogenic fetal disorders, and placental-related disorders, subjects that have been intensively studied by several groups around the world. The aim of this review was to assess the Brazilian research and clinical scenarios regarding the utilization of commercially available tests that use these plasma markers, stressing the advantages, both economic and safety-related, that non-invasive tests have when compared to those currently used in the Brazilian public health system.

Hormona del crecimiento y prolactina en líquido amniótico y plasma materno durante el embarazo normal / Growth hormone and prolactin in maternal plasma and amniotic fluid during normal gestation

Objective. To measure the concentration of human growth hormone (GH) and prolactin (PRL) In maternal plasma (MP) and amniotic fluid (AF) during gestation and to evaluate their correlation. Methods. HC and PRL were measured by radioimmunoassay in 60 healthy women with uncomplicated singleton pregnancies at 16-36 weeks of gestation (WG). Trends of both hormones were estimated throughout pregnancy. The correlation of either hormone measured in different fluids was also estimated. Results. GH in AF (AF-GH) decreased significantly throughout pregnancy; (AF-GH = 21.32 - 0.54 X WG, r = -0.72 [95% confidence intervals (95% CI) -0.57-0.82], p = 0.001), and increased in MP (MP-GH); (MP-GH = 2.73 +0.11 X WG, r = 0.45 [95% CI, 0.21-0.63]p = 0.05). The correlation between MP-GH and AF-GH was, (AF-GH = 16.28 - 1.54 x - M-PGH, r = -0.47 [95% CI, -0.64 --0.21]; p = 0.01). PRL values did not show significant differences neither in AF (AF-PRL / WG, r = 0.06, p = 0.6) nor in MP (MP-PRL / WG, r = 0.25, p = 0.14) during pregnancy, being AF-PRL (mean 151.3 ng/mL, SD 34.2 ng/mL) significantly higher than MP-PRL (mean 119.3 ng/mL, SD 55.4 ng/mL) (p = 0.006) in all the studied period. Conclusion. AF-GH and MP-GH showed a significant negative correlation during pregnancy. PRL measured in AF and PM did not show changes throughout gestation being AF-PRL significantly higher than MP-PRL.

Objetivo. Medir los valores de hormona del crecimiento (HC) y prolactina (PRL) en el líquido amniótico (LA) y en el plasma materno (PM) durante el embarazo normal y analizar sus asociaciones. Métodos. HC y PRL fueron medidas en el LA y en el PM por medio de radioinmunoanálisis en 60 mujeres con embarazo único y sin complicaciones entre 16 y 36 semanas de gestación (SG). Se evaluaron las tendencias de ambas hormonas a lo largo del embarazo y la correlación entre los valores obtenidos en ambos compartimentos. Resultados. La HC en LA (HCLA) disminuyó en forma significativa durante el embarazo (HCLA = 21.32 - 0.54 X SG, r = -0.72 [intervalos de confianza al 95% (IC 95%) -0.57-0.82], p = 0.001) y en PM (HCPM) aumentó (HCPM = 2.73 + 0.11 X SG, r = 0.45 [IC 95%, 0.21-0.63] p = 0.05). La correlación entre los valores de HC en LA y en PM fue: (HCLA = 16.28-1.54 x -HCPM, r = -0.47 [IC 95% -0.64 -0 -0.21]; p = 0.01). La concentración de PRL a lo largo del embarazo tanto en LA (PRL-LA/SG, r = 0.06, p = 0.6) como en PM (PRL-PM/SG r = 0.25, p = 0.14) no cambió y fue significativamente más alta en LA que en PM (LA; media 151.3 ng/mL, DE 34.2 ng/ inL, PM; media 119.3 ng/mL, DE 55.4 ng/mL, respectivamente, p = 0.006). Conclusiones. HC en PM y HC en LA presentan una correlación inversa a lo largo del embarazo, en tanto que los valores de PRL en ambos compartimentos no cambian, siendo significativamente más elevados en el LA.