IMMUNOTHERAPY DECREASES SEASONAL RISE IN SERUM-SOLUBLE CD23 IN SEASONAL ALLERGIC RHINITIS

There is increasing in vitro evidence that soluble CD23 (sCD23) is cap able of potentiating IgE synthesis, but the in vivo physiologic signif icance remains to be established.This study investigated the seasonal changes in sCD23 in patients with seasonal allergic rhinitis. It inclu ded 112 adult patients with seasonal allergic rhinitis due to Japanese cedar pollens and 20 nonatopic healthy volunteers. The 64 patients of the pharmacotherapy group were treated with nonsedating antihistamine tablets alone throughout the pollen season and the remaining 48 patie nts of the immunotherapy group continued to be treated with immunother apy. Serum concentrations of sCD23 were measured in each patient, befo re and during the pollen season of 1996, by a sandwich enzyme-linked i mmunosorbent assay. The serum levels of sCD23 in the pharmacotherapy g roup before the pollen season were significantly higher than those in the nonatopic group (P = .0130) and those in the immunotherapy group ( P = .0316). Seasonal increase in sCD23 was significant in the pharmaco therapy group, irrespective of the clinical response (P < .0001). By c ontrast, sCD23 was not significantly increased in the good responders to immunotherapy (P = .1826), but was significantly increased in the p oor responders to immunotherapy (P = .0052). A significant correlation between seasonal increase in rate in specific IgE and seasonal increa se in rate in sCD23 was confirmed in both the pharmacotherapy group (r (s) = 0.321, P = .0107) and the immunotherapy group (r(s) = 0.474, P = .0012). In conclusion, seasonal rise in sCD23 is associated with and is probably involved in seasonal rise in specific IgE in patients with seasonal allergic rhinitis, and successful immunotherapy is capable o f blunting seasonal increase in sCD23, thus resulting in attenuation o f seasonal increase in specific IgE and clinical benefits during the p ollen season.