Immunotherapy with a mass unit Parietaria judaica extract: a tolerance study with evidence of immunological changes to the major allergen Par j 1.J Investig Allergol Clin Immunol. 1999 Sep-Oct; 9(5):321-9.JI
Specific immunotherapy with Parietaria judaica pollen extract has been proven to be effective in the treatment of patients with respiratory allergy induced by this pollen. Nevertheless, there is some controversy about its tolerability. We conducted an open uncontrolled study to evaluate the tolerability of an aluminium adsorbed P. judaica pollen extract whose major allergen (Par j 1) content was known. Changes in immunological parameters to a complete P. judaica extract and to a purified Par j 1 preparation were monitored. Twenty-one patients (12 women, 9 men; mean age 30.2 years) suffering from rhinoconjunctivitis and/or asthma due to Parietaria pollen were enrolled. The maximum dose was established at 10 BU/ml (0.6 microgram Par j 1). Skin and conjunctival reactivity as well as serum levels of specific IgE, IgG, IgG1 and IgG4 were evaluated before therapy (T0), when 1 BU was given (T1), 2 weeks after the maintenance dose was reached (T2) and after the pollen season (T3). Four-hundred and fifteen doses were administered during immunotherapy. Only one systemic reaction (0.24% of doses) and two local reactions were registered. Reactions occurred during the administration of the highest concentrated vial. Before immunotherapy, purified Par j 1 accounted for 94.2% of the cutaneous response elicited by the complete extract. A statistically 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 significant increase during the study, while specific IgE levels initially decreased and increased after the pollen season. The kinetics of specific antibodies to P. judaica complete extract and purified Par j 1 showed a parallel trend. The present study demonstrates that immunotherapy with P. judaica extract is well tolerated in patients suffering from rhinoconjunctivitis and/or asthma due to Parietaria pollen. This therapy induces specific changes in the immunological response to P. judaica and to purified Par j 1. These changes can be detected at very early stages of therapy.