Oral cromolyn in food allergy: in vivo and in vitro effects

The results obtained in vivo in a group of 24 patients treated with oral cromolyn and compared to a group of 10 patients treated with placebo are reported. All patients were affected by adverse clinical reactions (urticaria and/or angioedema) related to food ingestion. A significant reduction of signs and symptoms were observed after oral cromolyn therapy only in the patients affected by true food allergy (FA), i.e., IgE mediated reactions. No adverse reactions appeared in the treated patients. Because we found an enhancing effect exerted in vitro by cromolyn (SCG) on T-cell responsiveness in previous studies, in the present investigation we analyzed in more detail in vitro effects of SCG on T lymphocytes [i.e., phytohemagglutinin-induced interleukin-2 (IL-2) production] and IL-2 receptor expression on T cells. No significant effect was induced by SCG on IL-2 production, whereas IL-2 receptor expression on surface of T cells appeared significantly increased (P less than 0.001) by adding SCG in cultures. These clinical and immunological results are analyzed and discussed in relation to a possible in vivo effect(s) of cromolyn in allergic diseases.