The raport focuses on investigation of a sample of old people, mainly in their eighties, as against a control group of healthy subjects, aged between 25 and 40. In order to investigate the immunologic response the research has been carried on along the following lines. to show self Ab antinuclear (AAN), antimitochondrial (AM) and antismoth muscle (ASM), by using indirect immunofluorescence; to study alteration of serum immunoglobulins by using IDR; to study alteration of serum concentration of C3 fraction in the complement by using IDR; to determine immune complexes by using Haskova method; to investigate IR through R rosetting method. Immunologic reactivity (IR) disturbance was found, with respect to alteration of immunoglobulin ratio IgA, IgG, IgM vere slightly diminished. Self antibodies were present to a percentage of 17% as predominant of ASM, AM and AAN in decreasing order. Increase in C3 associated with increase in immune complexes could account for high incidence of cardio-vascular complications. Decline in IR is shown through the decrease in T lymphocytes where Ts is more markedly decreased as against decreased Ts. The results imbalance between stimulating activated cells and suppressive controlling cells. IR alteration could account for degenerative pathology in the subjects, namely, ATS, cardiovascular diseases, senility, pseudobulb syndrome, schizoaffective psychosis.