DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY OF IMMUNOTHERAPY WITH AN ALGINATE-CONJUGATED EXTRACT OF PARIETARIA-JUDAICA IN PATIENTS WITH PARIETARIA HAY-FEVER

A double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of immunotherapy (IT) with a partially purified a lginate-conjugated extract of Parietaria judaica (Conjuvac(R) Parietar ia, Dome/Hollister-Stier) in patients suffering from rhinoconjunctivit is caused by Parietaria pollen. Eighteen patients (10 women, 8 men, me an age 35 years) received active treatment and 17 (10 women, 7 men, me an age 42.5 years) received placebo. Actively treated patients had sig nificantly lower nasal symptom/medication scores (running nose P = 0.0 087 and sneezing P = 0.048) during the Parietaria pollen season. Signi ficant decreases in specific skin (P< 0.01), nasal (P< 0.05), and conj unctival (P< 0.01) reactivity to the Parietaria extract and significan t increases of specific IgG (P< 0.001), IgG1 (P< 0.001), and IgG4 (P< 0.001) in actively treated patients, but not in placebo, were found. I T was well tolerated, the active extract inducing five mild systemic r eactions (four rhinitis and one urticaria) and placebo two (rhinitis). A significant correlation was found between low skin reactivity and h igh specific IgG (P = 0.0002) and IgG4 (P = 0.036). These findings ind icate that IT with a partially purified P. judaica extract is an effec tive and safe treatment for Parietaria pollen allergy. The correlation between low immediate skin reactivity and high specific IgG and IgG4 suggests that, at least in the studied cutaneous model, these antibodi es may exert a blocking effect.