Australian researchers found babies born with hyperactive immune cells have higher chances of developing food allergies by their first year. An analysis of 1,000 umbilical cord blood from 2010 and 2013 revealed a connection between hyperactive immune cells and succeeding development of allergies from common food such as eggs, wheat, peanut and milk.
The team found an "immune signature" in the core blood samples. This signature included high numbers of monocytes, which are immune cells that were highly "triggered" in babies who later developed food allergies.
Monocytes respond quickly to infection and other immune system stresses. The researchers found that the monocytes' activation prior or during birth caused another type of immune cells, the T cells, to set off an immune response.
"We think that this immune change primes the baby for a food allergy," said Professor Len Harrison, an immunologist from the Walter and Eliza Hall Institute.
Harrison emphasized that a baby with the immune signature doesn't always develop food allergies. It only meant that the baby is susceptible to the development of common food allergies. This suggests the possible involvement of other factors during the baby's first year of life such as antibiotic use, exposure to solid food, infection and type of birth (normal or caesarean).
The types and amounts of food the mother eats also affect the baby's risk of food allergy development. The mother's consumption of food with additives and highly processed foods could also be in play.
The team is also interested in learning if genetic susceptibility is involved.
"This study really emphasizes how critical it is to look at pregnancy and early life to really understand why chronic immune and inflammatory disorders such as allergies develop in childhood and later," noted Harrison.
In the study, the first blood sample was taken from the baby's umbilical cord. The newborn participants were analyzed during the sixth and 12th months.
Australia has seen a surge in childhood food allergies in the past decades. Children below 5 years old were most susceptible to developing food allergies. The study was published in the Science Translational Medicine journal on Jan. 13.
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