The monitoring biomarker for immune function of lymphocytes in the elderly.

In this paper, we determined the number of peripheral blood lymphocytes (PBL) in the elderly and their proliferative response to PHA (Phytohemagglutinin). The data showed that the PBL number decreased with age. For the young group: 1680.0 +/- 644.7/microliters; the 60-69 years old group: 1284.0 +/- 492.3/microliters; the 70-79 years old group: 987.5 +/- 309.1/microliters, P < 0.05. The OD (optical density) value measured by MTT method for proliferative response of PBL in the elderly was 0.15 +/- 0.08, which was lower than the young group 0.18 +/- 0.05. Also, an apparent decline of soluble IL-2 receptor (sIL-2R) release from activated PBL in old people was found. The results suggested that the changes of PBL number and sIL-2R level could be considered as an indication of immune function of lymphocytes in the elderly.