USE OF MONOCLONAL-ANTIBODIES IN THE STANDARDIZATION OF PARIETARIA-JUDAICA ALLERGENIC EXTRACTS

Two monoclonal antibodies (MoAb) specific for Parietaria judaica aller genic components were selected on the basis of their capability to rec ognize either the Parietaria judaica major allergen (MoAb 1A6/1D1) or several other allergenic components (MoAb 1A4/2f8) except the major al lergen. These two antibodies, either individually or combined, were us ed to develop an ELISA-inhibition system using a reference Parietaria judaica extract (in-house Reference preparation, IHR). The assays perf ormed with these reagents were firstly standardized by testing the IHR several times. A good reproducibility, evaluated both at the level of 50% inhibition values, and in terms of analysis of the variance of th e slopes of the regression curves, was obtained. Subsequently, the pot ency of several Parietaria judaica extracts, either obtained by manufa cturing companies or produced in other laboratories, was evaluated by these tests. Data obtained by interpolation with the IHR values and ex pressed in terms of arbitrary units (AU) were compared with those obta ined by classical human IgE inhibition, performed with sera from aller gic patients. Results indicate that the monoclonal antibodies produced in our laboratory can be successfully employed, either individually o r combined, in the standardization of allergenic preparations in addit ion to, and possibly replacing, the classical IgE-based standardizatio n procedures which require human specimens often available in limited amounts only.