In vivo stimulation of peripheral lymphocytes to proliferation after oral challenge of children allergic to foods.

Abstract

During culture of peripheral lymphocytes of children suspected of allergy to foods, the lymphocytes of 6 children were found on more than one occasion to exhibit exceptionally active proliferation without <i>in vitro</i> addition of food protein to the culture, that is in the control culture. For reasons given this was not considered artifactual. The phenomenon was observed only after oral challenge with a suspected food, and never in children sensitive to inhalant allergens alone. Exceptionally active proliferation of the lymphocytes without addition of antigen <i>in vitro</i> suggests that antigenic stimulation of circulating sensitized lymphocytes occurred <i>in vivo.</i> This is credible in children allergic to foods, as antigenic substances may be absorbed from the gut during digestion of food. Analogous examples of <i>in vivo</i> stimulation of sensitized peripheral lymphocytes are reported in the literature.