Abstract
Toxoplasma gondii infection in pregnant females can cause congenital toxoplasmosis. Although maternal and infant immune profiles appear to play a role, studies on this topic are scarce. We analyzed SNPs in the regulatory regions of cytokine genes in 30 mother-newborn pairs, five mothers and two infants with known status, with respect to vertical transmission and the clinical outcome of those infected. Polymorphisms in the IL-2, IL-10, IL-12, IL-17, TNF-α, and TGF-β1 gene promoter or regulatory regions were obtained by sequencing, and genotype and allele frequencies were related to transmission and clinical outcome of the offspring. In children, the polymorphic “G" TNF-α −308 allele, as well as the related low- and high-level homozygous GG or TT genotypes of the 3′UTR region of the IL-12reg gene, were associated with congenital infection. Both cytokines have been shown to be expressed in the cyto- and syncytiotrophoblast; therefore, the fetus might be able to regulate infection at the placental level. In mothers of infected children, the T allele of the IL-12reg 3′UTR gene was associated with more severe disease in their offspring, suggesting that a strong maternal response reduces parasite spread in the fetus. Furthermore, SNPs in the promoter region of IL-2 and TGF-β1 genes were associated with elevated levels and milder disease in children with congenital infection, which is congruent with a regulation of a strong, damaging, inflammatory response. Our results suggest that some up and down regulatory cytokine genes may predispose to vertical transmission or disease severity in congenital toxoplasmosis.