[Age dependent frequency of cytoplasmic antibodies].
In a random sample of so-called healthy blood donors under and over 60 years of age (n=196 of 10,593 donations by about 4254 donors) the frequency of antibodies (antibodies against smooth muscles, mitochondria, microsomes, brush border of proximal rat renal tubuli, connective tissue, and parietal cells) detectable by immuno-fluorescence was determined and compared with the incidence thereof in various groups of diseases. In general, two frequency peaks (up to 30 and over 50 years of age) were observed; however, statistical evidence was obtained for the second peak only (with p less than 0.001). In "healthy" blood donors past 60 there was observed a significantly higher frequency of occurrence of antibodies against parietal cells (p less than 0.001) and against connective tissue (p less than 0.01). An attempt has been made to classify antibodies into four groups depending upon age disease, with due consideration being given to the different clinical valency of antibodies. Different frequencies of occurrence of numerous antibodies are believed to be due not only to immune system aging, but especially to the not-yet elucidated disturbance of regulation of autotolerance by alteration of immune cells, which is subject to endogenous (e.g., genetic) and exogenous (e.g. viral) factors that are dependent on age rather than aging.