IN-VITRO COMPLEMENT ACTIVATION BY RAGWEED ALLERGEN EXTRACT IN THE SERA OF RAGWEED ALLERGIC AND NONALLERGIC PERSONS

Ragweed allergen (RWA)-induced complement activation in sera of 40 RW allergic patients and of 40 non-allergic controls was investigated, Af ter treatment of the sera with RWA, levels of C3a, C5a, C3bBbP, ClrCls Clinh, SC5b-9 and granulocyte-aggregating activity were determined. Co ncentration of RW-specific IgG was also measured. After RWA treatment dose-dependent complement activation was detected in sera of RW allerg ic and non-allergic persons. C3a generation was observed mostly in the sera of RW allergic individuals, while levels of C3bBbP and of RW-spe cific IgG were significantly higher in sera of allergies, and a strong correlation was found between these two parameters. In a prospective clinical study, a significant positive correlation was observed betwee n the extent of RWA-induced alternative pathway (AP) activation and th e severity of symptoms of allergic rhinoconjunctivitis that were devel oped in a 4-week period subsequent to blood sampling. These observatio ns suggest that complement activation has a role in the development of the symptoms of RW allergy.