Publication date: Jan 25, 2025

Maternal obesity is a condition with increasing prevalence worldwide, that correlates with negative infant outcomes. Here we performed an observational cross-sectional study, where peripheral blood and colostrum samples from 37 mothers with BMI between 18. 5-25 or > 30 kg/m (21 and 16 mothers, respectively) were collected 24-48 h postpartum. B lymphocyte subpopulations were investigated using flow cytometry. IgG, IgA, and IgM concentrations, and antibody production from colostrum-resident B cells were quantified. Overall, nacEFve B lymphocytes were the most abundant subtype in peripheral blood, while CD27IgD double-negative B cells were the most B lymphocyte subtype abundant in colostrum. The colostrum from mothers with BMI > 30 kg/m contained significantly more IgG-secreting colostrum-resident B cells, more IgG, and less IgA. Mothers with BMI > 30 kg/m who had been vaccinated with the Pfizer BioNTech bivalent vaccine during the third trimester of pregnancy (n = 8) did not show higher IgA or IgG antibody responses against SARS-CoV-2 RBD in either tissue types compared to unvaccinated mothers, contrasting with mother of BMI between 18. 5-25 kg/m (n = 7). Similar trends were evidenced in colostrum post-Tdap vaccination. This is the first characterization of B lymphocyte subpopulations and antibodies in the colostrum of mothers with obesity. This work uncovers maternal obesity as a possible modifier of humoral immune components in colostrum.

Semantics

Original Article