Immunotherapy with a mass unit Parietaria judaica extract: A tolerance study with evidence of immunological changes to the major allergen Par j 1

Specific immunotherapy with Parietaria judaica pollen extract has been prov en to be effective in the treatment of patients with respiratory allergy in duced by this pollen. Nevertheless, there is some controversy about its tol erability. We conducted an open uncontrolled study to evaluate the tolerabi lity of an aluminium adsorbed P. judaica pollen extract whose major allerge n (Par j I) content was known. Changes in immunological parameters to a com plete P. judaica extract and to a purified Par j I preparation were monitor ed. Twenty-one patients (12 women, 9 men; mean age 30.2 years) suffering fr om rhinoconjunctivitis and/or asthma due to Parietaria pollen were enrolled . The maximum dose was established at 10 BU/ml (0.6 mu g Par j I). Skin and conjunctival reactivity as well as serum levels of specific IgE, IgG, IgG1 and IgG4 were evaluated before therapy (T-0), when 1 BU was given (T-1), 2 weeks after the maintenance dose was reached (T-2) and after the pollen se ason (T-3). Four-hundred and fifteen doses were administered during immunot herapy. Only one systemic reaction (0.24% of doses) and two local reactions were registered. Reactions occurred during the administration of the highe st concentrated vial. Before immunotherapy, purified Par j I accounted for 94.2% of the cutaneous response elicited by the complete extract A statisti cally significant decrease in cutaneous response was detected after 8 weeks of treatment There were no significant changes in conjunctival reactivity throughout the study. Specific IgG, IgG1 and IgG4 showed a pronounced and s ignificant increase during the study, while specific IgE levels initially d ecreased and increased after the pollen season. The kinetics of specific an tibodies to P judaica complete extract and purified Par j I showed a parall el trend. The present study demonstrates that immunotherapy with P. judaica extract is well tolerated in patients suffering from rhinoconjunctivitis a nd/or asthma due to Parietaria pollen. This therapy induces specific change s in the immunological response to P. judaica and to purified Par j I. Thes e changes can be detected at very early stages of therapy.