Active rosette-forming T cells in the elderly.

The numbers and percentages of active rosette-forming T cells were measured in two age groups, to assess the effects of aging. The study included 21 healthy persons in the 20--40 age group and 25 persons without major disease in the 60--85 age group. In the younger subjects the number of rosette-forming cells (RFC) averaged 1430 +/- 463/cu mm (mean and S.D.), a count not significantly different from that in the older subjects (1443 +/- 398/cu mm). Likewise, the active RFC count in the 20--40 age group (526 +/- 185/cu mm) and that in the 60--85 age group (558 +/- 197/cu mm) were not significantly different. There was no difference for the percentage total RFC (young 78 +/- 4%, elderly 78 +/- 6%) or the percentage active RFC (young 29 +/- 7%, elderly 30 +/- 6%). For the total lymphocyte count or the B lymphocyte count, there was no difference between the two groups of subjects. It is concluded that T lymphocytes, measured as total and active rosette-forming cells, are not decreased in healthy older persons.