Immunologic disturbances in cow's milk allergy, 1: delayed maturation of suppressor activity

Abstract
To assist in identifying pathogenetic mechanisms in different subtypes of cow's milk allergy (CMA), the function of immunoregulatory T-lymphocytes was studied. The study population consisted of 23 patients, mean [95% confidence interval] age of 25. 6 [19. 5, 33. 6] months, who had challenge-proven cow's milk allergy manifested with either skin (n=9) or gastrointestinal (n=14) symptoms; in addition, 13 age-matched disease controls were studied. Patients with challenge-proven CMA were rechallenged to establish whether they had acquired clinical tolerance to cow's milk. The suppressor activity of isolated lymphocytes was measured in vitro by a cell coculture at rechallenge and in 10/23 patients at diagnosis. At diagnosis, patients with CMA (n=10) showed a decreased mean [95% CI] suppressor activity, induced by either Concanavalin A, 7[-2, 15]%, or cow's milk, 3[-8, 14]% as compared with disease controls (n = 13), 19[15, 24]% and 24[17, 31]%; F = 7. 1, p = 0.004 and F = 6. 7, p = 0.005, respectively. At rechallenge the suppressor activity, induced both by Concanavalin A and cow's milk, reached the level of disease controls only in patients who had acquired clinical tolerance to cow's milk (n = 13/23), but not in those retaining CMA (n = 10/23). Our results indicate that the maturation of suppressor function is delayed in CMA, which might be of primary importance in the etiopathogenesis of CMA.