Early human milk lactoferrin during SARS-CoV-2 infection

Background/aim Early human milk provides protection against viral infections due to its high nutritional value, abundance of maternal antibodies and the specific role of lactoferrin (Lf). Lf blocks the early interaction between SARS-CoV-2 and host cells by binding to specific cell receptors and has been proposed as a preventative and adjunct treatment for COVID-19. This preliminary report aimed to investigate concentrations of Lf in early milk of SARS-CoV-2 positive mothers versus non-infected controls. Material and methods In a cohort of 13 SARS-CoV-2 positive mothers and 15 controls, breast milk concentrations of Lf were determined by ELISA on day 3 postpartum. Additionally, colostrum samples of infected mothers were analyzed for SARS-CoV-2 RNA detection and anti-SARS-CoV-2 IgA and IgG determination using RT-qPCR and ELISA, respectively. Results No differences were found in breast milk Lf concentrations between SARS-CoV-2 positive mothers and controls. In a subgroup analysis, however, symptomatic mothers (n = 7) presented with lower breast milk Lf concentrations, as compared to asymptomatic mothers (p = .041) and healthy controls (p = .029). All milk samples tested negative for SARS-CoV-2 RNA. Early human milk of infected mothers displayed IgA and IgG SARS-CoV-2 specific reactivity. Conclusions Our data showed a different early breast milk Lf "profile" between COVID-19 symptomatic and asymptomatic mothers with the latter being at non-COVID levels (control group). SARS-CoV-2 RNA was not detected in any breast milk sample. Early human milk Lf levels are potentially influenced by the severity of maternal COVID-19 infection during pregnancy.