Monitoring of specific IgG4 antibodies in respiratory allergy due to the pollen of Parietaria judaica. Evidence for a protective role.
Two groups of 20 patients having an allergic rhinitis due to the pollen of Parietaria judaica were studied, one received a treatment of specific hyposensitization, the other one a placebo. All of them were monosensitized. The study was carried out using double blind methodology and was conducted for one year. Each case was assessed by clinical tests: case history, skin tests, score symptoms, drug consumption, nasal provocation test and by in vitro tests (FAST technique): total and specific IgGE, specific IgG4. The clinical tests revealed a statistically significant improvement in the treated group as compared to those receiving the placebo. We found a statistically significant regular and important increase of specific IgG4 values in the treated group. In this case, the specific IgG4 antibodies most likely play a protective role and act as blocking antibodies.