Search

Background: IgG antibody to allergens in the serum of pollinosis patients is not routinely measured, because there are no simple methods for assaying small amounts of specific IgG in the serum ; so far only IgE and IgG4 antibodies have been assayed. In this study, we used a reverse-sandwich ELISA for measuring specific non-IgE,-IgG4 (probably, mainly IgG1) to Japanese cedar pollen allergens, and compared the antibody-positive rates and geometric mean antibody titers between pollinosis patients and non-patients (healthy individuals). Methods: Antibodies to two major allergens of Japanese cedar, Cry j 1 and Cry j 2, were assayed by the following methods : specific non-IgE,-IgG4 was measured by a reverse-sandwich ELISA ; specific IgE and IgG4 were measured by indirect ELISAs. Results: We detected specific non-IgE,-IgG4 in both the patients and non-patients. In comparison to the IgE antibody, which was detected in a small proportion of the non-patients with low titers, the non-IgE,-IgG4 antibody was present in a higher proportion with higher titers among both the patients and non-patients. Conclusions: Healthy individuals had specific non-IgE,-IgG4 to Japanese cedar allergens in a higher proportion than the specific IgE. The non-IgE,-IgG4 antibody assay may be useful in studies on the prevalence of allergen-specific antibody responders and may help in clarifying the natural history of pollinosis.

We examined the IgE and IgG antibody responses in Japanese cedar pollinosis patients before and after the pollination season for 2 years. The sera from 90 patients in 1990 and 87 in 1991, living in five regions in the Tokyo area, were obtained before and after the pollination season. In all patients, changes (increase then decrease) in specific IgE levels were detected after natural pollen exposure. Total IgE and specific IgG concentrations also changed. However, the degree of change in specific IgE was greater than those in total IgE and specific IgG. Then, the geometric means of specific and total IgE levels were compared among the five regions. These levels were found to be highest in the region where the pollen count was the highest. These findings suggest that IgE antibody production is more stimulated after natural pollen exposure compared to IgG antibody production, and is dependent on the amount of allergens.