T cell responses to a Parietaria judaica pollen extract: comparison between Parietaria‐sensitive patients, other atopics and healthy controls

Abstract

We investigated the in vitro proliferation of peripheral blood mononuclear cells (PBMC) from Parietaria-allergic subjects, atopic patients with other sensitizations and healthy controls to Parietaria judaica pollen extracts. PBMC from almost all 44 subjects, divided into five groups (Parietaria-, grass-, Parietaria and grass-, Dermatophagoides-sensitive patients and normal individuals) were able to proliferate in response to the extract without statistically significant differences between groups. Mean values of the stimulation indexes for the five groups were respectively: 10.73, 3.18, 5.50, 10,56, 9.28. The results of separation experiments showed that the responding cells were T lymphocytes. Mitogenic effect of the Parietaria pollen extract was excluded by the absence of proliferative PBMC response from cord blood of seven newborns. These results indicate that Parietaria-sensitive, other atopics and normal individuals have Parietaria-specific T cells able to proliferate in vitro to Parietaria allergens.