[Effect of the emotional state on immune functions: study on firstborn children on the occasion of the birth of a sibling].

The eventuality that a particular emotional involvement could weigh heavily on a person's psychophysical welfare, assuming a complementary role in the appearance of clinically noticeable pathologies (infections, allergies, neoplasms) has been object of several hypotheses which have been confirmed in researches on animals. Our research, by examining an unavoidable and surely natural situation like that one of the birth of a brother for a first born, a particularly severe for what affectivity is concerned, had the aim to evidence if there were some biological expressions, able to quantitatively settle the eventual immune functions' alterations indicative of a preexistent equilibrium. With this purpose have been examined several biological expressions indicative of immune functions (B lymphocytes, T lymphocytes, NK cells, lymphocyte transformation, chemotaxis, phagocytosis, C3 Complement fraction) in three first-born children with 2 to 3 years of age, whose mothers had in course a second pregnancy, during a period of about 20 months (from III pregnancy month to XIV month of age of the brother). The evolution of these immune functions evidence, during the whole period of observation, a non univocal performance. In the most of the cases was evidenced a variation towards diminution of the biological expression of some functions (lymphocyte transformation, T3 lymphocytes, T4 lymphocytes, T4/T8 rate, "E" Rosettes, chemotaxis and phagocytosis), while in the case of NK cells there were also variations towards augmentation. Particularly important were the variations towards diminution, that biological expressions as lymphocyte transformation and "E" Rosettes undergo. In two children the variations, towards diminution, showed themselves already before the birth of the brother. The variation of the T3 and T4 lymphocytes, of the T4/T8 rate, of chemotaxis and of phagocytosis were more limited. The values of the other examined biological expressions (T8, B7, C3) were in the normal range during the whole period of observation. Our results let us to attribute to emotional events, as in experimented model, the capacity to affect the biological expression that measures some immune functions, by depressing them in most of the cases, so in way to adulterate the immune equilibrium, and by setting the premises to upset the capability of immune defense in the examined persons. Our observations lead us to think that effectively, an event during which an important emotional state is induced, by upsetting the immune equilibrium, could more predispose a child (in this case the first born) to the action of pathogens.