Journal of Gerontology 1979. Vol. 34. No. I. 5-8
B and T Lymphocytes in Man IV. Circulating B, T and "Null" Lymphocytes in Aging Population1 Mohan M. Reddy, PhD, and Kong-oo Goh, MD2
T least two principal classes of lymphoA cytes, the thymus-dependent (T) and bone marrow-derived (B) lymphocytes, have
MATERIALS AND METHODS
Twenty-six laboratory personnel aged between 20 to 40 years comprised our control been recognized in man based on the origin group. Seventy-two subjects, aged between' and function of these cells (Raff, 1973). In 60 to 96 years, were chosen at random general, T cells are responsible for cell-medi- from the Monroe Community Hospital and ated immunity; and B cells are responsible for County Home; and blood was obtained from humoral immunity. However, these two types the routine laboratory tests when they visited of cells usually function dependently. They the Clinic. The blood samples were coded can be identified on the basis of differences in until the analyses were completed. Two vacutheir membrane properties. Human T cells can tainer tubes (10 ml) of EDTA (ethylene-diabe identified by their ability to form nonim- mine tetraacetic acid) anticoagulated blood mune rosettes with sheep erythrocytes (E was obtained from each subject and mixed rosettes). B lymphocytes can be identified by with an equal volume of a Balanced Salt Solu(a) the presence of easily detectable surface tion containing iron filings (Lymphocyte immunoglobulin (SIg), and (b) a receptor for separating reagent, Technicon Products, antigen-antibody-complement complexes. A Tarrytown, NY) to remove the monocytes third subpopulation of lymphocytes is known (Birnbaum, 1976). The mixture was then inas "Null" cells as they cannot be classified cubated at 37C for 30 min with frequent shaking as either T or B cells based on the presently and layered onto a ficoll-hypaque mixture to separate the lymphocytes. available techniques. T lymphocytes were determined by rosette The study of T and B cells in human peripheral blood has provided some useful informa- formation with sheep red blood cells (SRBC). tion in understanding certain diseases (Row- SRBC were washed twice with Hanks' Ballands & Daniele, 1977). Since there is some anced Salt Solution (HBSS) and adjusted to a evidence to indicate alterations in T and B 1% suspension. One-million lymphocytes suscells in aging population (Kay & Makinodan, pended in 0.25 ml HBSS were mixed with 0.25 1976; Walford, 1974), we report here our obser- ml of 1% SRBC, and the mixture was centrivations of B and T cells distribution in young fuged at 200g for five min and then stored in adults (20-40 yrs) and in aged humans (60-96 the refrigerator (4C) overnight. Samples were yrs). put in a hemocytometer chamber, and the frequency of rosette-forming lymphocytes was counted. A lymphocyte binding three or 'This research was supported in part by the National Cancer lnst. Grant more SRBC was considered a rosette-forming CA 14876. Rita Giuliano. Jack Evans and Janet Erickson gave technical assistance. lymphocyte. A drop of Giemsa stain added in 2 Univ. of Rochester School of Medicine and Dentistry, and Monroe the cell mixture can facilitate counting. Each Community Hospital. Rochester. NY. 14603.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
T, B and "Null" lymphocytes were determined in the peripheral blood of 98 adults, 26 of them were between 20 to 40 years of age and 72 between 60 to 96 years of age. The total number of lymphocytes were about the same in both groups. The percent and absolute number of T cells decreased significantly in the aged. Although the percent of B lymphocytes increased with age, the absolute number of B lymphocytes remained about the same.
REDDY AND GOH
forming cells were counted. Each sample was tested in duplicate and at least 200 cells were counted. None or less than 1% lymphocytes formed rosettes when unsensitized SRBC were tested as controls. RESULTS
The total number of lymphocytes in young adults was 2548 ± 154 (mean ± standard error) compared to 2202 ± 131 in aged humans (Table 1). This difference is not statistically significant. However, we found a significant reduction in the percent and absolute number of T cells in aged humans. In contrast to the T cells, we observed only an increase in the percent of B cells in the aged humans. The absolute number of B cells using both methods of B cell determination were about the same in the aging population. Table 2 shows the distribution of T, B and "Null" lymphocytes in aged humans in successive decades of life. The percent of B lymphocytes increased with progressive increase in age. We found no apparent association between the age groups of successive decades and total or T lymphocytes. DISCUSSION
The total number of lymphocytes in the peripheral blood of the young and old subjects did not differ significantly. This observation is in agreement with the findings of Weksler and Hutteroth (1974). However, MacKinney (1978) observed a significant age-dependent decline in absolute lymphocytes. He observed a sharp decline in absolute lymphocyte count in
Table 1. Distribution of T, B and "Null" Lymphocytes in Aging Population. Age (yrs)
20-40(n = 26) (mean = 28) 60-96(n = 72) (mean = 79) p Value 0 a
Total Lymphocytes per mm3 (mean + SE)
T Lymphocytes (E) (mean ± SE) % per mm3a
B Lymphocytes (SIg) (mean ± SE) % per mm3
B Lymphocytes (EAC) (mean ± SE) % per mm 3
"Null" Lymphocytes (mean ± SE) %*> per mm 3
2548 ± 154
61.5 ± 1 . 3
1564 ± 95
21.3+1.2
538 + 41
20.3 ± 1 . 4
512 ± 49
17.2+1.6
448 + 55
2202 ± 131
53.7± 1.7
1189 ± 7 9
31.3±1.6
675 + 62
25.6± 1.4
528 ± 44
15.8+1.5
353 + 39
NSd
< 0.01
< 0.02
< 0.001
NS
< 0.05
NS
NS
NS
The mean was calculated from each individual's value. b "Null." lymphocytes = 100 - T + B (SIg). c According to Student's /-test. d N o t Significant.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
sample was tested in duplicate. At least 200 lymphocytes were counted to calculate the percent of T lymphocytes. B lymphocytes were determined by the surface immunofluorescence method (Goh & Reddy, 1976). Essentially, one-million cells suspended in 0.1 ml of HBSS were stored at 4C for 30 min with an equal volume of fluorescein isothiocynate conjugated goat anti-human globulin (Grand Island Biological Co.). After storage, the cells were washed three times with HBSS and resuspended in 0.1 ml of 5% fetal calf serum in HBSS. One drop of cell suspension was placed on a slide, covered with a coverglass, then sealed with nail polish. The slide was examined under a Leitz fluorescent microscope. At least 200 cells per specimen were counted to determine the percent of B cells. B lymphocytes were also determined by the EAC rosette method (Kermanetal., 1976). Five ml of a 5% solution of washed SRBC was incubated for 30 min at 37C in a water bath with 5 ml of rabbit anti-SRBC sera (Microbiological Associates, Bethesda, Md.) diluted 1/2,500 in HBSS. The cells were washed three times and resuspended in 5 ml HBSS. Five ml of a 1/10 dilution of mouse sera (Cappel Laboratories, Inc., Cochranville, Pa.) were added, and the suspension was incubated for 30 min at 37C. The sensitized SRBC were washed and adjusted to 0.5% final concentration in HBSS. One-million lymphocytes suspended in 0.25 ml HBSS were mixed with 0.25 ml of 0.5% sensitized SRBC and centrifuged at room temperature for two min at 200 g and then incubated for 30 min at 37C. The cell pellet was resuspended by vigorous shaking and rosette-
T AND B LYMPHOCYTES IN AGING
Table 2. Distribution of T, B and "Null" Lymphocytes in the Aged in Successive Decades of Life. Age (yrs)
T Lymphocytes (E) (mean ± SE) % per mm3
B Lymphocytes (SIg) (mean ± SE) % per mm3
B Lymphocytes (EAC) (mean ± SE) % per mm3
" N u l l " Lymphocytes (mean ± SE) % per mm3
2314 + 245
51.1 ± 3 . 4
1215 ± 157
25.9±2.7
584 ± 80
23.0±2.8
490 ± 58
23.0 it 3.1
516 ± 83
2399 ± 281
55.4 ±3.1
1393 ±208
32.7 ± 3 . 3
678 ± 48
26.2 ± 2 . 4
552 ± 41
12.9 ± 2 . 2
345 ± 83
1779 ± 1 1 6
50.4±4.0
895 ± 87
31.5 ± 2.6
559 ± 60
24.3 ± 2.7
399 ± 42
18.5 ± 3.4
331 ± 64
2246 ± 320
57.3 ± 2 . 9
1198 ±114
34.9 ± 3 . 6
865 ± 220
29.0 ±3.1
653 ± 154
9.5 ±2.2
218 ± 62
the first two decades of life, remained constant during the next three decades and then declined at an accelerated rate thereafter. We have not included the under 20 years age group in our study. Our study also indicates that both the percent and absolute number of T cells decreased significantly in the aging population and is accompanied by a significant increase in the percent but not the absolute number of B cells. This is different from those reported by Weksler and Hutteroth (1974) but agrees with those of Diaz-Jouanen et al. (1975) who showed a decline in T cells which was concomitant with a proportional increase in B cells in the aging population. The reduction of T cells in the aging population has been reported by other investigators using direct measurement (Augener et al., 1974; Carosella etal., 1974; Smith etal., 1974) and also by their responsiveness to phytohemagglutinin (DiazJouanen et al., 1975; Girard et al., 1977; Halbrecht et al., 1977; Pisciotta et al., 1967; Weksler & Hutteroth, 1974). A decline of T cells in aging could be associated with a deficiency of (a) helper cells or (b) suppressor cells, or (c) a combination of helper and suppressor cells. A decline of helper cells causes a decline in B cell differentiation to antibody producing cells. This will affect the T-dependent antibody responses. A deficiency of suppressor cells in aging results in the emergence of clones of B cells capable of producing various autoantibodies resulting in autoimmune diseases. An increase in autoantibodies has been observed in elderly subjects (Diaz-Jouanen et al., 1975; Hallgren et al., 1973). In conclusion, we have demonstrated a significant decrease in peripheral blood T
lymphocytes with age. The decrease of T lymphocytes in the aging population could be due to the atrophy of the thymus after puberty (MacKinney, 1978). SUMMARY
Human peripheral blood lymphocytes can be divided into at least two major subpopulations based on their origin and function. These are known as bone-marrow-derived or B lymphocytes, and thymus-derived orT lymphocytes. In general, B cells are responsible for antibody-mediated immunity, and T cells are responsible for cell-mediated immunity. However, these cell types usually do not function independently, but interact with one another. A third subpopulation of lymphocytes is known as "Null" cells as they cannot be classified as either T or B cells based on currently available techniques. Since there is some evidence to indicate alterations in T and B cells in aging population, we determined B, T and "Null" lymphocytes in the peripheral blood obtained from 26 subjects who were between 20 to 40 years of age and 72 subjects who were between 60 and 96 years of age. The total number of lymphocytes per cubic millimeter was about the same in both groups. The percent and absolute number of T cells were reduced significantly in the aged group compared to the 20 to 40 years age group. Although the percentage of B lymphocytes was increased in the aged, the absolute number of B lymphocytes remained about the same in both groups. The decreased number of T cells observed in our study with advancing age could be due to the atrophy of the thymus after puberty.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
60-69(n=l8) (mean = 66) 70-79 (n = 20) (mean = 74) 80-89(n=l6) (mean = 84) 90-96 ( n = 18) (mean = 92)
Total Lymphocytes per mm3 (mean ± SE)
REDD Y AND GOH
REFERENCES
Hallgren, H. M., Buckley, C. E. Ill, Gilbertsen, V. A., & Yunis, E. J. Lymphocyte phytohemagglutinin responsiveness, immunoglobulins and autoantibodies
in aging humans. Journal of Immunology, 1973, / / / , 1101-1107. Kay, M. M. B., & Makinodan, T. Immunobiology of aging: Evaluation of current status. Clinical Immunol-
ogy and Immunopathology, 1976,6, 394-413. Kerman, R., Smith, R., Ezdinli, E., & Stefani, S. Unification and technical aspects of total T, active T and B lymphocyte rosette assays. Immunological Communications, 1976,5, 685-694. MacKinney, A. A. Jr. Effect of aging on the peripheral blood lymphocyte count. Journal of Gerontoloqy, 1978, 33, 213-216. Pisciotta, A. V., Westring, D. W., DePrey, C , & Walsh, B. Mitogenic effect of phytohemagglutinin at different ages. Nature, 1967,2/5, 193-194. Raff, M. C. Tand B lymphocytes and immune responses. Nature, 1973,242, 19-23. Rowlands, D. T., Jr., & Daniele, R. P. Lymphocyte subpopulations in human' disease. Human Pathology, 1977,5, 117-120. Smith, M. A., Evans, J., & Steel, C. M. Age-related variation in proportion of circulating T cells. Lancet, 1974, 2, 922-924. Walford, R. L. Immunologic theory of aging: Current status. Federation Proceedings, 1974, 33, 2020-2027. Weksler, M. E., & Hutteroth, T. H. Impaired lymphocyte function in aged humans. Journal of Clinical Investigation, 1974, 5J. 99-104.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
Augener, W., Cohnen, G., Reuter, A., & Brittinger, G. Decrease of T lymphocytes during aging. Lancet, 1974, /, 1164. Birnbaum, G. Numbers of rosette-forming cells in human peripheral blood. Cellular Immunology, 1976, 21, 371-378. Carosella, E. D., Mochanko, K., & Braun, M. Rosetteforming T cells in human peripheral blood at different ages. Cellular Immunology, 1974, 12, 323-325. Diaz-Jouanen, E., Strickland, R. G., & Williams, R. C. Jr. Studies of human lymphocytes in the newborn and the aged. American Journal of Medicine, 1975, 58, 620-628. Girard, J. P., Paychere, M., Cuevas, M., & Fernandes, B. Cell-mediated immunity in an aging population. Clinical and Experimental Immunology, 1977, 27, 85-91. Goh, K. O., & Reddy, M. M. B and T lymphocytes in man II. Circulating B and T lymphocytes in cancer patients. Journal of Medicine, 1976,7, 297-305. Halbrecht, I., Komlos, L., & Strauss, Z. Lymphocyte reactivity in the aged. Journal of the American Geriatrics Society, 1977, 25, 354-357.
B and T Lymphocytes in Man IV. Circulating B, T and "Null" Lymphocytes in Aging Population1 Mohan M. Reddy, PhD, and Kong-oo Goh, MD2
T least two principal classes of lymphoA cytes, the thymus-dependent (T) and bone marrow-derived (B) lymphocytes, have
MATERIALS AND METHODS
Twenty-six laboratory personnel aged between 20 to 40 years comprised our control been recognized in man based on the origin group. Seventy-two subjects, aged between' and function of these cells (Raff, 1973). In 60 to 96 years, were chosen at random general, T cells are responsible for cell-medi- from the Monroe Community Hospital and ated immunity; and B cells are responsible for County Home; and blood was obtained from humoral immunity. However, these two types the routine laboratory tests when they visited of cells usually function dependently. They the Clinic. The blood samples were coded can be identified on the basis of differences in until the analyses were completed. Two vacutheir membrane properties. Human T cells can tainer tubes (10 ml) of EDTA (ethylene-diabe identified by their ability to form nonim- mine tetraacetic acid) anticoagulated blood mune rosettes with sheep erythrocytes (E was obtained from each subject and mixed rosettes). B lymphocytes can be identified by with an equal volume of a Balanced Salt Solu(a) the presence of easily detectable surface tion containing iron filings (Lymphocyte immunoglobulin (SIg), and (b) a receptor for separating reagent, Technicon Products, antigen-antibody-complement complexes. A Tarrytown, NY) to remove the monocytes third subpopulation of lymphocytes is known (Birnbaum, 1976). The mixture was then inas "Null" cells as they cannot be classified cubated at 37C for 30 min with frequent shaking as either T or B cells based on the presently and layered onto a ficoll-hypaque mixture to separate the lymphocytes. available techniques. T lymphocytes were determined by rosette The study of T and B cells in human peripheral blood has provided some useful informa- formation with sheep red blood cells (SRBC). tion in understanding certain diseases (Row- SRBC were washed twice with Hanks' Ballands & Daniele, 1977). Since there is some anced Salt Solution (HBSS) and adjusted to a evidence to indicate alterations in T and B 1% suspension. One-million lymphocytes suscells in aging population (Kay & Makinodan, pended in 0.25 ml HBSS were mixed with 0.25 1976; Walford, 1974), we report here our obser- ml of 1% SRBC, and the mixture was centrivations of B and T cells distribution in young fuged at 200g for five min and then stored in adults (20-40 yrs) and in aged humans (60-96 the refrigerator (4C) overnight. Samples were yrs). put in a hemocytometer chamber, and the frequency of rosette-forming lymphocytes was counted. A lymphocyte binding three or 'This research was supported in part by the National Cancer lnst. Grant more SRBC was considered a rosette-forming CA 14876. Rita Giuliano. Jack Evans and Janet Erickson gave technical assistance. lymphocyte. A drop of Giemsa stain added in 2 Univ. of Rochester School of Medicine and Dentistry, and Monroe the cell mixture can facilitate counting. Each Community Hospital. Rochester. NY. 14603.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
T, B and "Null" lymphocytes were determined in the peripheral blood of 98 adults, 26 of them were between 20 to 40 years of age and 72 between 60 to 96 years of age. The total number of lymphocytes were about the same in both groups. The percent and absolute number of T cells decreased significantly in the aged. Although the percent of B lymphocytes increased with age, the absolute number of B lymphocytes remained about the same.
REDDY AND GOH
forming cells were counted. Each sample was tested in duplicate and at least 200 cells were counted. None or less than 1% lymphocytes formed rosettes when unsensitized SRBC were tested as controls. RESULTS
The total number of lymphocytes in young adults was 2548 ± 154 (mean ± standard error) compared to 2202 ± 131 in aged humans (Table 1). This difference is not statistically significant. However, we found a significant reduction in the percent and absolute number of T cells in aged humans. In contrast to the T cells, we observed only an increase in the percent of B cells in the aged humans. The absolute number of B cells using both methods of B cell determination were about the same in the aging population. Table 2 shows the distribution of T, B and "Null" lymphocytes in aged humans in successive decades of life. The percent of B lymphocytes increased with progressive increase in age. We found no apparent association between the age groups of successive decades and total or T lymphocytes. DISCUSSION
The total number of lymphocytes in the peripheral blood of the young and old subjects did not differ significantly. This observation is in agreement with the findings of Weksler and Hutteroth (1974). However, MacKinney (1978) observed a significant age-dependent decline in absolute lymphocytes. He observed a sharp decline in absolute lymphocyte count in
Table 1. Distribution of T, B and "Null" Lymphocytes in Aging Population. Age (yrs)
20-40(n = 26) (mean = 28) 60-96(n = 72) (mean = 79) p Value 0 a
Total Lymphocytes per mm3 (mean + SE)
T Lymphocytes (E) (mean ± SE) % per mm3a
B Lymphocytes (SIg) (mean ± SE) % per mm3
B Lymphocytes (EAC) (mean ± SE) % per mm 3
"Null" Lymphocytes (mean ± SE) %*> per mm 3
2548 ± 154
61.5 ± 1 . 3
1564 ± 95
21.3+1.2
538 + 41
20.3 ± 1 . 4
512 ± 49
17.2+1.6
448 + 55
2202 ± 131
53.7± 1.7
1189 ± 7 9
31.3±1.6
675 + 62
25.6± 1.4
528 ± 44
15.8+1.5
353 + 39
NSd
< 0.01
< 0.02
< 0.001
NS
< 0.05
NS
NS
NS
The mean was calculated from each individual's value. b "Null." lymphocytes = 100 - T + B (SIg). c According to Student's /-test. d N o t Significant.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
sample was tested in duplicate. At least 200 lymphocytes were counted to calculate the percent of T lymphocytes. B lymphocytes were determined by the surface immunofluorescence method (Goh & Reddy, 1976). Essentially, one-million cells suspended in 0.1 ml of HBSS were stored at 4C for 30 min with an equal volume of fluorescein isothiocynate conjugated goat anti-human globulin (Grand Island Biological Co.). After storage, the cells were washed three times with HBSS and resuspended in 0.1 ml of 5% fetal calf serum in HBSS. One drop of cell suspension was placed on a slide, covered with a coverglass, then sealed with nail polish. The slide was examined under a Leitz fluorescent microscope. At least 200 cells per specimen were counted to determine the percent of B cells. B lymphocytes were also determined by the EAC rosette method (Kermanetal., 1976). Five ml of a 5% solution of washed SRBC was incubated for 30 min at 37C in a water bath with 5 ml of rabbit anti-SRBC sera (Microbiological Associates, Bethesda, Md.) diluted 1/2,500 in HBSS. The cells were washed three times and resuspended in 5 ml HBSS. Five ml of a 1/10 dilution of mouse sera (Cappel Laboratories, Inc., Cochranville, Pa.) were added, and the suspension was incubated for 30 min at 37C. The sensitized SRBC were washed and adjusted to 0.5% final concentration in HBSS. One-million lymphocytes suspended in 0.25 ml HBSS were mixed with 0.25 ml of 0.5% sensitized SRBC and centrifuged at room temperature for two min at 200 g and then incubated for 30 min at 37C. The cell pellet was resuspended by vigorous shaking and rosette-
T AND B LYMPHOCYTES IN AGING
Table 2. Distribution of T, B and "Null" Lymphocytes in the Aged in Successive Decades of Life. Age (yrs)
T Lymphocytes (E) (mean ± SE) % per mm3
B Lymphocytes (SIg) (mean ± SE) % per mm3
B Lymphocytes (EAC) (mean ± SE) % per mm3
" N u l l " Lymphocytes (mean ± SE) % per mm3
2314 + 245
51.1 ± 3 . 4
1215 ± 157
25.9±2.7
584 ± 80
23.0±2.8
490 ± 58
23.0 it 3.1
516 ± 83
2399 ± 281
55.4 ±3.1
1393 ±208
32.7 ± 3 . 3
678 ± 48
26.2 ± 2 . 4
552 ± 41
12.9 ± 2 . 2
345 ± 83
1779 ± 1 1 6
50.4±4.0
895 ± 87
31.5 ± 2.6
559 ± 60
24.3 ± 2.7
399 ± 42
18.5 ± 3.4
331 ± 64
2246 ± 320
57.3 ± 2 . 9
1198 ±114
34.9 ± 3 . 6
865 ± 220
29.0 ±3.1
653 ± 154
9.5 ±2.2
218 ± 62
the first two decades of life, remained constant during the next three decades and then declined at an accelerated rate thereafter. We have not included the under 20 years age group in our study. Our study also indicates that both the percent and absolute number of T cells decreased significantly in the aging population and is accompanied by a significant increase in the percent but not the absolute number of B cells. This is different from those reported by Weksler and Hutteroth (1974) but agrees with those of Diaz-Jouanen et al. (1975) who showed a decline in T cells which was concomitant with a proportional increase in B cells in the aging population. The reduction of T cells in the aging population has been reported by other investigators using direct measurement (Augener et al., 1974; Carosella etal., 1974; Smith etal., 1974) and also by their responsiveness to phytohemagglutinin (DiazJouanen et al., 1975; Girard et al., 1977; Halbrecht et al., 1977; Pisciotta et al., 1967; Weksler & Hutteroth, 1974). A decline of T cells in aging could be associated with a deficiency of (a) helper cells or (b) suppressor cells, or (c) a combination of helper and suppressor cells. A decline of helper cells causes a decline in B cell differentiation to antibody producing cells. This will affect the T-dependent antibody responses. A deficiency of suppressor cells in aging results in the emergence of clones of B cells capable of producing various autoantibodies resulting in autoimmune diseases. An increase in autoantibodies has been observed in elderly subjects (Diaz-Jouanen et al., 1975; Hallgren et al., 1973). In conclusion, we have demonstrated a significant decrease in peripheral blood T
lymphocytes with age. The decrease of T lymphocytes in the aging population could be due to the atrophy of the thymus after puberty (MacKinney, 1978). SUMMARY
Human peripheral blood lymphocytes can be divided into at least two major subpopulations based on their origin and function. These are known as bone-marrow-derived or B lymphocytes, and thymus-derived orT lymphocytes. In general, B cells are responsible for antibody-mediated immunity, and T cells are responsible for cell-mediated immunity. However, these cell types usually do not function independently, but interact with one another. A third subpopulation of lymphocytes is known as "Null" cells as they cannot be classified as either T or B cells based on currently available techniques. Since there is some evidence to indicate alterations in T and B cells in aging population, we determined B, T and "Null" lymphocytes in the peripheral blood obtained from 26 subjects who were between 20 to 40 years of age and 72 subjects who were between 60 and 96 years of age. The total number of lymphocytes per cubic millimeter was about the same in both groups. The percent and absolute number of T cells were reduced significantly in the aged group compared to the 20 to 40 years age group. Although the percentage of B lymphocytes was increased in the aged, the absolute number of B lymphocytes remained about the same in both groups. The decreased number of T cells observed in our study with advancing age could be due to the atrophy of the thymus after puberty.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
60-69(n=l8) (mean = 66) 70-79 (n = 20) (mean = 74) 80-89(n=l6) (mean = 84) 90-96 ( n = 18) (mean = 92)
Total Lymphocytes per mm3 (mean ± SE)
REDD Y AND GOH
REFERENCES
Hallgren, H. M., Buckley, C. E. Ill, Gilbertsen, V. A., & Yunis, E. J. Lymphocyte phytohemagglutinin responsiveness, immunoglobulins and autoantibodies
in aging humans. Journal of Immunology, 1973, / / / , 1101-1107. Kay, M. M. B., & Makinodan, T. Immunobiology of aging: Evaluation of current status. Clinical Immunol-
ogy and Immunopathology, 1976,6, 394-413. Kerman, R., Smith, R., Ezdinli, E., & Stefani, S. Unification and technical aspects of total T, active T and B lymphocyte rosette assays. Immunological Communications, 1976,5, 685-694. MacKinney, A. A. Jr. Effect of aging on the peripheral blood lymphocyte count. Journal of Gerontoloqy, 1978, 33, 213-216. Pisciotta, A. V., Westring, D. W., DePrey, C , & Walsh, B. Mitogenic effect of phytohemagglutinin at different ages. Nature, 1967,2/5, 193-194. Raff, M. C. Tand B lymphocytes and immune responses. Nature, 1973,242, 19-23. Rowlands, D. T., Jr., & Daniele, R. P. Lymphocyte subpopulations in human' disease. Human Pathology, 1977,5, 117-120. Smith, M. A., Evans, J., & Steel, C. M. Age-related variation in proportion of circulating T cells. Lancet, 1974, 2, 922-924. Walford, R. L. Immunologic theory of aging: Current status. Federation Proceedings, 1974, 33, 2020-2027. Weksler, M. E., & Hutteroth, T. H. Impaired lymphocyte function in aged humans. Journal of Clinical Investigation, 1974, 5J. 99-104.
Downloaded from http://geronj.oxfordjournals.org/ at University of Birmingham on July 6, 2015
Augener, W., Cohnen, G., Reuter, A., & Brittinger, G. Decrease of T lymphocytes during aging. Lancet, 1974, /, 1164. Birnbaum, G. Numbers of rosette-forming cells in human peripheral blood. Cellular Immunology, 1976, 21, 371-378. Carosella, E. D., Mochanko, K., & Braun, M. Rosetteforming T cells in human peripheral blood at different ages. Cellular Immunology, 1974, 12, 323-325. Diaz-Jouanen, E., Strickland, R. G., & Williams, R. C. Jr. Studies of human lymphocytes in the newborn and the aged. American Journal of Medicine, 1975, 58, 620-628. Girard, J. P., Paychere, M., Cuevas, M., & Fernandes, B. Cell-mediated immunity in an aging population. Clinical and Experimental Immunology, 1977, 27, 85-91. Goh, K. O., & Reddy, M. M. B and T lymphocytes in man II. Circulating B and T lymphocytes in cancer patients. Journal of Medicine, 1976,7, 297-305. Halbrecht, I., Komlos, L., & Strauss, Z. Lymphocyte reactivity in the aged. Journal of the American Geriatrics Society, 1977, 25, 354-357.
