Little is known about the immunological causes of food allergies. Studies are showing that the blood in the umbilical cords of infants who went on to have food allergies had overactive immune cells at birth. Their cord blood had more monocytes, compared with CD4+ T cells, and decreased numbers of regulatory T cells. Moreover, the monocytes from food- allergic infants secreted more inflammatory cytokines than those from healthy infants. Researchers believe that events during pregnancy may play a part in determining whether food allergies might develop in the child later. An excess of monocytes may be a warning sign that the immune system may overreact to harmless proteins in food, causing dangerous and life-threatening reactions. These findings suggest the need for anti-inflammatory approaches to prevent hyperreactions later.
Source: Science Translational Medicine, January 13, 2016