SENSITIZATION TO ZYGOPHYLLUM-FABAGO POLLEN - A CLINICAL AND IMMUNOLOGICAL STUDY

Zygophyllum fabago is a herbaceous plant found widely in the Mediterra nean area. There are no previous reports of its allergenicity. An aero biologic and clinical survey was conducted in Murcia, southern Spain, to determine the quantity of airborne pollen and establish the possibl e role of this pollen as a cause of allergic symptoms. With a Hirst vo lumetric trap, we determined the atmospheric concentrations of this po llen in 1993, 1994, 1995, and 1996. Of 1180 patients tested, 181 (15.3 4%) had a positive skin test. To determine its allergenicity, we divid ed 47 patients into three groups: in group 1, all the patients had sym ptoms of rhinoconjunctivitis plus asthma; in groups 2 and 3, rhinoconj unctivitis. In group 1, we performed a bronchial provocation test (BPT ); in groups 2 and 3, we performed nasal provocation (NPT) and conjunc tival provocation (CPT) tests, respectively. SDS-PAGE was used to char acterize the antigenic fractions and RAST inhibition to determine cros s-reactivity with other pollens. The pollen dispersion period is from May to September (445 grains/m(3)). BPT was positive in 13 of 15 patie nts, NPT in 14 of 16 patients, and CPT in 13 of 16 patients. RAST inhi bition revealed cross-reactivity with Mercurialis, Ricinus, Olea, and Betula. SDS-PAGE identified 25 IgE antibody-binding components, five o f which (60, 65, 41, 38, and 15.5/14.7 kDa) were recognized by 40% of the sera. By SDS-PAGE immunoblotting with sunflower antiprofilin rabbi t serum and affinity chromatography we established that the Z. fabago extract has profilin. This study shows that this pollen becomes airbor ne and elicits an IgE response which triggers respiratory symptoms in allergic subjects.