RESUMEN
The aim of this work was to study the effects of aging on the cellular-mediated immune response and to search for any alterations in the total lymphocyte count and the absolute number of T-lymphocytes accompanying aging of man. This study was carried out on: thirty four Egyptian farmers above 60 years old [mean age= 66.4 years] and they were 22 females + 12 males and they were apparently healthy and on 17 healthy Egyptian farmers [mean age = 37.6 years] and they were 9 females + 8 males as control. All studied individuals were subjected to full history taking, clinical examination and fresh samples of peripheral blood were taken to count the total lymphocytes, and the lymphocytes had been isolated using the ficoll-hypaque. The absolute T-lymphocytes were estimated using the E-rosette formation between sheep RBC's and the lymphocyte suspension. T-cell percent to total lymphocytes were estimated. Results showed that: - There were no decrease in the lymphocyte count with aging; in the older group it was =2113/mm[3] while in the control group, it was 2106/mm[3]. The percentage of T-lymphocytes showed no appreciable change with aging; in the geriatric group it was =69.2% while in the control group = 69.5% i.e. As light decrease with aging had happened. The absolute T-lymph count showed no change with aging: In the old group it was =1465/mm[3], while in the control group = 1459 /mm[3] i.e. in both groups it was [nearly] equal. From these results, it was concluded that; aging is not accompanied with alterations in the total lymphocytic count or in the absolute T-cell number/mm[3]. It was referred that aging is associated with changes in cell-mediated immune response, these changes are mainly functional and due to alterations in the T-cell subset-proportions in the body of man