Australasian Science: Australia's authority on science since 1938

Food Allergy Linked to Hyperactive Immune System at Birth

Babies with hyperactive immune cells at birth, detected in their cord blood, are more likely to develop food allergies in their first year of life. The finding, published in Science Translational Medicine (www.tinyurl.com/zmfu9ov), could lead to future treatments that prevent childhood food allergies.

Prof Len Harrison of the Walter and Eliza Hall Institute (WEHI) said that the study of the cord blood of more than 1000 newborns “found a link between children who had hyperactive immune cells at birth and the development of allergies to milk, eggs, peanuts, wheat and other common foods in their first years of life”.

Lead author Dr Yuxia Zhang of WEHI said that babies at risk of developing food allergies had activated immune cells at birth. “In at-risk babies, immune cells called monocytes were activated before or during birth. Signals from these cells encouraged the development of immune responses by specialised immune cells called T cells that were predisposed to cause allergic reactions to some foods.”

The research used well-documented food allergy information collected by the Barwon Infant Study (BIS), a collaboration between Barwon Health, Deakin University and the Murdoch Childrens Research Institute.

“There has been a threefold increase in hospital presentations due to food allergy over recent decades, and most of this increase has been among children under 5 years of age,” said co-author A/Prof Peter Vuillermin, who leads the BIS. “In fact, up to one in every ten babies in Melbourne develop food allergy during the first year of life.

“We don’t know why the increase in food allergy has occurred. The important thing about this study is that we’ve shown the immune systems of babies who develop food allergy are in a sense ‘primed’ for allergic disease by the time they are born.”

Harrison said that the research team would try to identify why these babies have hyperactive immune cells. “Are the immune cells inherently activated because of the baby’s genes or do they become activated at the time of birth or earlier in pregnancy, and how?” he asked.

“This study really emphasises 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.”