RESUMEN
The influence of cigarette smoking on T cell subsets has been studied in white subjects, but comparable data are not available for blacks. We analyzed peripheral blood mononuclear cell subsets in a population-based, stratified, random sample of healthy black adults using monoclonal antibodies and flow cytometry. The study population consisted of 94 men and 79 women, including 73 smokers (CS) and 100 nonsmokers (NS). Cigarette smoking was associated with a significant elevation in leukocyte (WBC) count (CS 7,270 +/- 230 cells/mm3 versus NS 6,260 +/- 160 cells/mm3; p = 0.001), although WBC counts for both groups were substantially lower than those reported for white smokers and nonsmokers. Smokers had a significantly lower proportion of CD4+ cells than nonsmokers (CS 55.4 +/- 0.9% versus NS 58.7 +/- 0.9; p = 0.01), adjusting for age and gender. No significant smoking-related changes were observed for CD8+ cells, the CD4/CD8 ratio, or total T cells (CD3+), monocytes (CD14+), or natural killer cells (CD16+). Among black smokers, a significant dose-related decrease in CD4+ cells was observed as the number of cigarettes smoked per day increased. Among black exsmokers, the level of WBC and CD4+ cells returned to the level observed in never smokers within 2 to 5 yr after smoking cessation. These results contrast sharply with the previously reported increase in CD4+ cells and decrease in natural killer cells associated with cigarette smoking in whites. The data suggest that the immunologic effects of cigarette smoking may be significantly modified by ethnic characteristics.
Asunto(s)
Población Negra , Fumar/inmunología , Subgrupos de Linfocitos T , Adulto , Anciano , Femenino , Humanos , Recuento de Leucocitos , Leucocitos Mononucleares/inmunología , Masculino , Persona de Mediana Edad , Valores de ReferenciaRESUMEN
The effect of cryopreservation and long-term liquid nitrogen storage on peripheral blood mononuclear cell (PBMC) subsets was prospectively analyzed using monoclonal antibodies and flow cytometry. Brief cryopreservation did not significantly alter the proportion of positively stained cells for CD3+, CD4+, CD8+, CD14+, CD16+, and CD19+ cells. A small but statistically significant increase in the proportion of positive cells was observed for HLA-DR+ and HLe-1+ cells. Brief cryopreservation was associated with a decrease in the mean fluorescence intensity (MFI) values for CD3+, CD4+, and CD8+ cells; an increase in MFI values for CD14+ and HLA-DR+ cells; and no change for CD16+, CD19+, and HLe-1+ cells. There was no significant change in the proportion of CD3+, CD4+, or CD16+ cells during 20 months of storage in liquid nitrogen. Small but statistically significant decreases in the proportion of CD8+ and CD19+ cells were observed over the same interval, and the proportion of CD14+ cells (monocytes) was highly variable. Chronologic changes in fluorescence intensity during long-term storage were observed for all cell subsets except CD16+ and CD19+ cells. Cryopreservation is a valuable technique for long-term storage of viable cells. For many laboratory applications, the small changes noted in the present study will have no practical importance. However, for clinical and epidemiological investigations encompassing large numbers of samples, statistical techniques to adjust for small changes during storage should be considered.
Asunto(s)
Conservación de la Sangre/métodos , Criopreservación/métodos , Citometría de Flujo/métodos , Leucocitos Mononucleares , Antígenos CD/aislamiento & purificación , Humanos , Subgrupos Linfocitarios , Nitrógeno , Linfocitos TRESUMEN
Little is known about the normal range and variability of T-cell subsets in older children. We analyzed peripheral blood mononuclear cell subsets in 112 healthy children, ages 12-19 years (mean +/- SD: 15.4 +/- 1.9 years), using monoclonal antibodies and flow cytometry. The study population included 28 blacks and 84 whites, with 59 boys and 53 girls. The mean +/- SD cell subset values were: CD3+ T cells, 74.0 +/- 7.8%; CD4+ helper-inducer T cells, 46.8 +/- 6.9%; CD8+ suppressor-cytotoxic T cells, 27.3 +/- 5.7%; CD4:CD8 helper:suppressor ratio, 1.81 +/- 0.57; CD16+ natural killer cells, 4.4 +/- 3.1%; CD19+ B cells, 10.0 +/- 5.3%; CD14+ monocytes, 20.0 +/- 6.5%; and HLA-DR cells, 15.4 +/- 4.8%. Overall, boys had a higher proportion of HLA-DR+ cells than girls, attributable to an increase in CD19+ B cells. Blacks tended to have a higher proportion of HLA-DR+ cells than whites, apparently due to an increase in activated T cells. Detailed analysis by age group revealed a striking transition in the pattern of CD4+ and CD8+ cell populations. The CD4:CD8 ratio, higher in boys than girls for ages 12-16, was reversed to the "adult" pattern in 17-19 year olds, with a higher CD4:CD8 ratio in girls. These data provide important baseline values for healthy children and stress the importance of establishing normative ranges for pediatric subjects separately from adults.
Asunto(s)
Linfocitos T/inmunología , Adolescente , Envejecimiento/inmunología , Antígenos de Diferenciación de Linfocitos T/análisis , Población Negra , Niño , Femenino , Citometría de Flujo , Humanos , Recuento de Leucocitos , Leucocitos Mononucleares/análisis , Masculino , Población BlancaRESUMEN
To investigate the influence of cigarette smoking on mononuclear cell subsets, we determined T cell, B cell, monocyte, and HLA-DR+ subsets in a population-based, stratified, random sample of healthy Caucasians using monoclonal antibodies and flow cytometry. The study population consisted of 282 subjects 20 to 69 yr of age, including 108 smokers and 174 nonsmokers. Multivariate analysis techniques were used to assess the influence of cigarette smoking status after controlling for the effects of age and gender. Cigarette smoking was associated with a nonspecific increase in the leukocyte count involving all major cell types (smokers: 8.50 +/- 0.15 versus nonsmokers: 7.33 +/- 0.12 cells/mm3; p less than or equal to 0.0001). In addition, cigarette smokers had a selective increase in CD4+ cells (helper-inducer T cells) compared with nonsmokers (55.3 +/- 0.8 versus 52.2 +/- 0.6% of lymphoid cells; p = 0.002), resulting in a statistically significant increase in the CD4+/CD8+ (helper/suppressor) ratio (2.42 +/- 0.1 versus 2.13 +/- 0.16; p = 0.02). There was no significant difference between smokers and nonsmokers in the level of CD3+ cells (total T cells: 76.8 +/- 0.7 versus 76.1 +/- 0.5; p = 0.5), CD8+ cells (suppressor-cytotoxic T cells: 25.7 +/- 0.8 versus 27.0 +/- 0.5%; p = 0.1), CD19+ cells (B cells) (10.7 +/- 0.4 versus 10.0 +/- 0.3%; p = 0.2), CD14+ cells (monocytes) (18.0 +/- 0.6 versus 17.0 +/- 0.4%; p = 0.2), or HLA-DR+ cells (14.5 +/- 0.5 versus 14.0 +/- 0.4%; p = 0.4).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Fumar/inmunología , Linfocitos T/clasificación , Adulto , Anciano , Antígenos de Diferenciación de Linfocitos T/análisis , Femenino , Antígenos HLA-DR/análisis , Humanos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Fumar/efectos adversos , Población BlancaRESUMEN
To investigate the influence of age, race, and gender on the cellular immune system, we determined T-cell, B-cell, monocyte, natural killer (NK)-cell, and HLA-DR+-cell subsets in 266 nonsmokers from a population-based random sample of healthy adults using monoclonal antibodies and flow cytometry. Blacks had a lower total white blood-cell count than whites (P less than or equal to 0.0001), due primarily to a decrease in granulocytes. There was no significant difference in absolute lymphocyte count between blacks and whites. Blacks had a higher proportion of CD19+ cells (Leu 12+ B cells) and a lower proportion of CD3+ cells (OKT3+ T cells) than whites (P less than or equal to 0.01). Female sex and increasing age were independently associated with an increased percentage of CD4+ cells (OKT4A+ helper-inducer T-cell subset), resulting in a higher helper/suppressor ratio among women and older individuals (P less than or equal to 0.05). Black race and increasing age were independently associated with an increased proportion of HLA-DR+ cells (P less than or equal to 0.0001) which was not attributable to B cells or monocytes. No significant age, race, or gender effects were observed for CD14+ cells (Leu M3+ monocytes) or CD16+ cells (Leu 11A+ natural killer cells). These data demonstrate that age, race, and gender are each associated with significant differences in peripheral blood mononuclear-cell subsets. Population-based data such as these provide an important foundation for future design and interpretation of human flow cytometry data.
Asunto(s)
Antígenos de Superficie/análisis , Leucocitos Mononucleares/clasificación , Adulto , Factores de Edad , Anciano , Anticuerpos Monoclonales , Linfocitos B/inmunología , Recuento de Células Sanguíneas , Separación Celular , Femenino , Citometría de Flujo , Antígenos HLA-DR , Humanos , Células Asesinas Naturales/inmunología , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Grupos Raciales , Factores Sexuales , Factores Socioeconómicos , Linfocitos T/inmunologíaRESUMEN
To investigate the relationship between cigarette smoking and the level of circulating natural killer (NK) cells, we studied 282 subjects from a population-based, stratified random sample of healthy persons. NK cells were enumerated by flow cytometry using the monoclonal antibody anti-Leu 11A. Cigarette smokers had a significantly lower proportion of NK cells than did subjects who had never smoked (5.5 +/- 0.3% versus 7.4 +/- 0.4% of lymphoid cells; p = 0.0002). NK cells were also decreased among ex-smokers (5.6 +/- 0.4%; p = 0.002), including subjects who had not smoked for more than 20 yr. The white blood cell and lymphocyte counts were increased in smokers compared with those in never smokers (p less than 0.0001). In contrast to NK cells, the smoking-related changes in leukocyte count were not present in ex-smokers, even those who had stopped smoking within the past year. Multivariate analysis confirmed that both current and past smokers had significant decreases in both the number and proportion of NK cells after controlling for age, sex, and lymphocyte count. These data indicate that cigarette smoking is associated with a decrease in the number and proportion of circulating NK cells, and that this effect is present many years after smoking cessation. This quantitative NK cell deficit may contribute to the elevated risk of malignancy in this population.