In vitro IgE synthesis in neonates with different family history of atopy.

In this study we want to correlate family history of atopy and in vitro synthesis of IgE, IL4 and IFN gamma in 5 neonates with biparental (group A), 5 with uniparental (group B) and 5 with absent family history of atopy (group C). An aliquot of neonatal blood mononuclear cells (NBMC) was incubated in presence of PHA in combination with the phorbol ester acetate (TPA). The supernatants of cultures were harvested after 48-72 hours of incubation and stored at -20 degrees C until testing for lymphokine production by ELISA kits. Only one neonate of group B showed detectable in vitro synthesis of IL4 (45 pg/ml) after PHA + TPA stimulation. All the others failed to produce detectable levels either of IL4 or IFN gamma. Another aliquot of NBMC was cultured in the presence of saturating concentrations of rhIL4 for 48 h. After this pre-incubation step, the non-adherent cells were cultured in the presence of: 1) rhIL4; 2) rhIL4 + anti-IL4 antibody (Ab); 3) rhIL4 + anti-IFN gamma Ab; 4) rhIFN gamma, 5) rhIFN gamma + anti-IFN gamma Ab + rhIL4; 6) PWM + rhIL4; 7) unstimulated culture. The supernatants of these cultures were tested for their IgE content. In general, spontaneous IgE production by NBMC was very low, rhIL4 did not induce a significant increase of IgE synthesis. The other modalities of stimulations did not produce significative changes. We did not observe significative differences among the three groups of neonates. On the basis of our results, we conclude that NBMC aren't able to produce significative amounts of IgE in vitro either spontaneously or after IL4 stimulation. This test and the evaluation of IL4 and IFN gamma in vitro production aren't useful markers of atopy predisposition.