Age-related increase of autoantibodies to interleukin 1 alpha in healthy Japanese blood donors

• Published in: The journal of medical investigation Vol. 44; no. 1-2; p. 89
• Main Authors: Ohmoto, Y, Ogushi, F, Muraguchi, M, Yamakawa, M, Sone, S
• Format: Journal Article
• Language: English
• Published: Japan 01.08.1997
• Subjects: Adolescent; Adult; Aging - blood; Aging - immunology; Autoantibodies - blood; Blood Donors; Female; Humans; Interleukin-1 - immunology; Male; Middle Aged; Radioimmunoassay - methods
• ISSN: 1343-1420

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.