Assuntos
Insulinoma/diagnóstico por imagem , Pâncreas/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Exenatida , Feminino , Radioisótopos de Gálio , Compostos Heterocíclicos com 1 Anel/química , Humanos , Hiperinsulinismo/etiologia , Hiperinsulinismo/cirurgia , Hipoglicemia/etiologia , Hipoglicemia/cirurgia , Insulinoma/complicações , Insulinoma/cirurgia , Pessoa de Meia-Idade , Pâncreas/cirurgia , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/cirurgia , Pancreaticojejunostomia , Peptídeos/química , Resultado do Tratamento , Peçonhas/químicaRESUMO
Vitamin A supplementation reduces child mortality in populations at risk of vitamin A deficiency and may also reduce maternal mortality. One possible explanation for this is that vitamin A deficiency is associated with altered immune function and cytokine dysregulation. Vitamin A deficiency in pregnancy may thus compound the pregnancy-associated bias of cellular immune responses towards Th-2-like responses and exacerbate susceptibility to intracellular pathogens. We assessed mitogen and antigen-induced cytokine responses during pregnancy and lactation in Ghanaian primigravidae receiving either vitamin A supplementation or placebo. This was a double-blind, randomized, placebo-controlled trial of weekly vitamin A supplementation in pregnant and lactating women. Pregnancy compared to postpartum was associated with a suppression of cytokine responses, in particular of the proinflammatory cytokines interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha. Mitogen-induced TNF-alpha responses were associated with a decreased risk of peripheral parasitaemia during pregnancy. Furthermore, vitamin A supplementation was significantly associated with an increased ratio of mitogen-induced proinflammatory cytokine (IFN-gamma) to anti-inflammatory cytokine (IL-10) during pregnancy and in the postpartum period. The results of this study indicate that suppression of proinflammatory type 1 immune responses and hence immunity to intracellular infections, resulting from the combined effects of pregnancy and vitamin A deficiency, might be ameliorated by vitamin A supplementation.