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Dynamics of immunoglobulin G subclasses during the first two years of life in Malawian infants born to HIV-positive mothers

2020; BioMed Central; Volume: 20; Issue: 1 Linguagem: Inglês

10.1186/s12887-020-02091-z

1471-2431

Silvia Baroncelli, Clementina Maria Galluzzo, Giuseppe Liotta, Mauro Andreotti, Stefano Orlando, Fausto Ciccacci, Haswell Jere, Richard Luhanga, Jean Baptiste Sagno, Roberta Amici, Maria Cristina Marazzi, Marina Giuliano,

Immune responses and vaccinations

Maternal antibodies are key components of the protective responses of infants who are unable to produce their own IgG until 6 months of life. There is evidence that HIV-exposed uninfected children (HEU) have IgG levels abnormalities, that can be partially responsible for the higher vulnerability to infections in the first 2 years of the life of this population. This retrospective study aimed to characterize the dynamics in plasma levels of total IgG and their isotypes during the first 2 years of life in HEU infants exclusively breastfed through 6 months of age.Total IgG, IgG1, IgG2, IgG3 and IgG4 isotypes, and IgM and IgA plasma concentrations were determined by nephelometric methods in 30 Malawian infants born to HIV-positive women at month 1, 6 and 24 of life.At 1-month infants had a median concentration of total IgG of 8.48 g/l, (IQR 7.57-9.15), with an overrepresentation of the IgG1 isotype (89.0% of total) and low levels of IgG2 (0.52 g/l, IQR, 0.46-0.65). Total IgG and IgG1 concentrations were lower at 6 months (- 2.1 and - 1.12 g/dl, respectively) reflecting disappearance of maternal antibodies, but at 24 months their levels were higher with respect to the reported reference values for age-matched pairs. Abnormal isotype distribution was still present at 24 months with IgG2 remaining strongly underrepresented (0.87 g/l, 7.5% of total IgG).HIV exposure during pregnancy and breastfeeding seems to influence the IgG maturation and isotype distribution that persist in 2-year old infants.