Association between HLA-G 3'UTR 14-bp polymorphism and HIV vertical transmission in Brazilian children.

OBJECTIVES: The aim of our study was to verify the possible association between an HLA-G 14-bp deletion/insertion polymorphism and perinatal HIV transmission in Brazilian children.

DESIGN: We analyzed the 14-bp deletion/insertion polymorphisms in seronegative (i.e., exposed uninfected, N = 71) and seropositive (exposed infected, N = 175) Brazilian children born from HIV-positive mothers and in healthy controls (n = 175).

METHODS: HLA-G 14-bp deletion/insertion polymorphism (rs16375) was detected by PCR amplification of the target sequence followed by agarose gel electrophoresis. All the samples were also analyzed by direct sequencing in order to validate the genotyping results.

RESULTS: HIV-exposed uninfected children showed significant differences in their allele and genotype frequencies of the HLA-G 14-bp polymorphism when compared to both seropositive children and healthy controls. The 14-bp-deleted (D) allele was more frequent in exposed uninfected children (79%) than in healthy controls (60%) and HIV-positive children (58%); the higher percentage of the D allele found in the exposed uninfected children with respect to HIV-positive individuals was significantly associated with a reduced risk of vertical transmission. This effect was ascribable to the presence of the D/D homozygous genotype.

CONCLUSION: Our findings support the possible role for the HLA-G 14-bp deletion/insertion polymorphism in the HIV vertical transmission in Brazilian children. The presence of the D allele and D/D genotype is associated with a protective effect toward HIV perinatal infection.