title: Age-related increase of autoantibodies to interleukin 1 alpha in healthy Japanese blood donors.
abstract: Although autoantibodies to interleukin-1 alpha (IL-1 alpha autoantibodies) are known to be present in sera of apparently healthy humans, their frequency of occurrence and significance are unclear. To determine the prevalence of detectable IL-1 alpha autoantibodies in normal human blood, we screened the plasma of blood donors (6290 subjects: 3977 men and 2313 women, ages 16 to 64 yr) by a radioimmununoassay which we developed using a method that could detect over 5 ng/ml. Moreover, we investigated immunoglobulin class of IL-1 alpha autoantibodies and also their function. IL-1 alpha autoantibodies were detected in 14.6% of the 6290 donors. Their frequency was higher in males than females (16.6% vs. 11.2%, p < 0.01) and increased with age in both sexes. The proportion of subjects with a high IL-1 alpha autoantibodies titers also increased with age. We showed that IL-1 alpha autoantibodies were of the IgG class and that they had neutralizing function to IL-1 alpha by receptor assay. Neutralizing activity was only shown in plasma with concentration of IL-1 alpha autoantibodies, the level of which was over 1000 ng/ml. The affinity of the IL-1 alpha autoantibodies in plasma was between 2.1 x 10(-10) and 1.2 x 10(-9) M (mean 6.4 x 10(-10)M). Our results provide a basis for comparison with IL-1 alpha autoantibodies prevalence between healthy states and disease states, and suggest that IL-1 alpha autoantibodies may play a significant role in modulating the effects of excessive IL-1 alpha at local site or in systemic regions.
authors.affiliation: Otsuka Pharmaceutical Co, Tokushima, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ohmoto
authors.forename: F
authors.initials: F
authors.lastname: Ogushi
authors.forename: M
authors.initials: M
authors.lastname: Muraguchi
authors.forename: M
authors.initials: M
authors.lastname: Yamakawa
authors.forename: S
authors.initials: S
authors.lastname: Sone
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000097:blood / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D001782:Blood Donors; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D001323:Autoantibodies; D007375:Interleukin-1