Lymphocyte Subsets In Children Research Articles

Peripheral blood T lymphocyte subsets in children with congenital asplenia

The aim of the current study was to examine whether a congenital lack of the spleen changes distribution, state of activation and function of peripheral lymphocyte T subsets. Seven children with congenital asplenia (CA) aged 1.5-17 years and seven age-matched controls were tested. By triple-color flow cytometry we examined: (1) the expression of CD3(+), CD4(+), CD8(+), CD19(+), and CD56(+) on lymphocytes; (2) the distribution of CD45RA(+) and CD45RO(+) in CD4(+) and CD8(+); (3) the expression of CD27(+) in the CD4(+) and CD8(+) T-cell-bearing CD45RA(+), CD45RO(+), or CD45RB(+). Lymphocyte proliferative responses and cytokines production (IFN-gamma, IL-6, TNF-alfa, and IL-10) in anti-CD3-induced peripheral blood mononuclear cells were tested. The results indicate (1) a normal distribution of the basic lymphocyte subsets, (2) low CD3(+)/CD8(+) percentage but expressing CD8(+high) and non-significantly elevated CD4(+)/CD8(+) ratio, (3) CD45RA(+high) and CD27(+high) in the CD4(+) and CD8(+) T cell, and (4) CD45RB(+high) in the CD4(+) and CD45RO(+high) in the CD8(+). The distribution of CD27(+) in the CD45RA(+) and CD45RO(+) CD4(+) T cells remained unchanged. However, the percentage of CD8(+)/CD45RO(+)/CD27(+) T cells tended to be elevated. Altogether, these data indicate that CA is connected with (1) the presence CD4(+) T cells expressing the "naive" phenotype (CD45RA(+high) RB(+high) and CD27(+high)), (2) high numbers of activated CD8(+) T cells shifted toward the memory phenotype (CD45RO(+high)) but still showing high CD27(+) expression, which may indicate failure in T CD8(+) cytotoxic effectors differentiation, and (3) a tendency to the rather pro-inflammatory status of cells, low IL-10 expression, and suboptimal lymphocytes responses to mitogenic stimulation.

Dynamics of lymphocyte subsets in children living in an area polluted by polychlorinated biphenyls

Immune system development, particularly in the pre-natal and early post-natal periods, has far-reaching health consequences during childhood, as well as throughout life. Exposure to poly-chlorinated biphenyls (PCBs) during pre-natal and early life has been previously associated with changes in the incidence of infectious and allergic diseases in children, and humoral immunity alterations. Lymphocyte immunophenotyping is an important tool in the diagnosis of immunologic and hematologic disorders. This study used a lysed whole blood method for analysis of lymphocyte sub-populations in samples from children born and living in two districts: a highly-contaminated area (Michalovce) and one (Svidnik/Stropkov) with ≈ 2-fold lower environmental PCB levels. The percentages of B-lymphocytes (CD19+), activated HLADR+CD19+ cells, and CD8+ T-lymphocytes significantly increased at 6- and 16-months-of-age in both selected regions as compared to in cord blood values (p < 0.001). Levels of CD3+ cells increased significantly (from 61 to 65%) in samples from Michalovce (p < 0.01). Levels of CD4+ T-lymphocytes declined 10% among 16-month-olds in both regions (Michalovce at p < 0.001 and Svidnik/Stropkov at p < 0.01). Natural killer (NK) cell levels decreased 50% in Michalovce 6- and 16-month-old children and 42% among 6-month-olds in Svidnik/Stropkov (p < 0.001). Compared with the less-contaminated region, Michalovce samples showed significantly higher expression of CD3+ T-lymphocytes, B-lymphocytes, and activated B-lymphocytes, whereas NK cells were less expressed. Even after adjustment for selected covariates, e.g., maternal cigarette smoking, age, parity, ethnicity, birth weight, and gender of infant, the levels of CD19+, HLADR+CD19+, and CD3−CD(16 + 56)+ cells were seen to remain significantly different between the districts. These results showed that early-life environmental PCB exposure was associated with fluctuations in major lymphocyte subsets in children, suggesting that there is a post-natal immune system response to PCB exposures.

Clinical research of changes of lymphocyte subsets in children with hand foot and mouth disease

目的 探讨手足口病(HFMD)患儿外周血T淋巴细胞亚群、B淋巴细胞、NK细胞的变化特点.方法 将41例HFMD患儿分为一般病例组23例,重症病例组18例,选择20例健康儿童作为对照组,采用流式细胞仪检测外周血T淋巴细胞亚群、B淋巴细胞、NK细胞.结果 CD3~+与CD4~+细胞表达:HFMD重症组、一般病例组、对照组依次显著降低(P＜0.01);CD8~+细胞表达:HFMD重症组、一般病例组、对照组依次显著降低(P＜0.05);NK细胞表达:HFMD重症组与一般病例组相似(P＞0.05),皆高于对照组(P＜0.05);B淋巴细胞表达:HFMD重症组、一般病例组、对照组依次升高(P＜0.01).结论 HFMD患儿免疫系统功能紊乱,其中细胞免疫有不同程度的抑制,体液免疫反应亢进。

Detection of T lymphocyte subsets of children withHelicobacter pyloriinfection

To study the transformation of T lymphocyte subsets in children with Heliobacter pylori (H pylori) infection. The H pylori infection status were determined by a combination of ELISA and Western blot (immunoblot) technique in 98 children and T lymphocyte subsets in peripheral blood were determined by flow cytometrical analysis. There were 75 children positive with H pylori infection and 23 negative in 98 children. Comparing the proportion of peripheral blood T lymphocytic subsets in children with H pylori infection and without H pylori infection, it was found that a higher proportion of CD4 T-cells in infected children (39.02+/-7.71 vs 34.25+/-10.73, t = 2.246,P<0.05) and higher value of CD4 to CD8 T-cells ratio (1.51+/-0.52 vs 1.25, t = 2.104, P<0.05) were present, but there were not significant differences in CD3 T-cells and CD8 T-cells (73.11+/-10.02 vs 69.49+/-17.08, 27.22+/-6.07 vs 28.27+/-8.67, P>0.05). Th1 cell-mediated immune responses may be induced by H pylori infection in children.

Lymphocyte subsets in healthy children from birth through 18 years of age: The pediatric AIDS clinical trials group P1009 study

Background Peripheral blood lymphocyte subsets need to be determined in a large, urban, minority-predominant cohort of healthy children to serve as suitable control subjects for the interpretation of the appearance of these cells in several disease conditions, notably pediatric HIV-1 infection. Objective We sought to determine the distribution of lymphocyte subsets in healthy urban-dwelling infants, children, and adolescents in the United States. Methods Lymphocyte subsets were determined by means of 3-color flow cytometry in a cross-sectional study of 807 HIV-unexposed children from birth through 18 years of age. Results Cell-surface marker analysis demonstrated that age was an extremely important variable in 24 lymphocyte subset distributions measured as percentages or absolute counts—eg, the CD4 (helper) T cell, CD8 (cytotoxic) T cell, CD19 B cell, CD4CD45RACD62L (naive helper) T cell, CD3CD4CD45RO (memory helper) T cell, CD8HLA-DRCD38 (activated cytotoxic) T cell, and CD8CD28 (activation primed cytotoxic) T cell. The testing laboratory proved to be an important variable, indicating the need for using the same laboratory or group of laboratories to assay an individual's blood over time and to assay control and ill or treated populations. Sex and race-ethnicity were much less important. Conclusion The results of this study provide a control population for assessment of the effects of HIV infection on the normal development and distribution of lymphocyte subsets in children of both sexes, all races, and all ethnic backgrounds from birth through 18 years of age in an urban population. This study's findings will also prove invaluable in interpreting the immune changes in children with many other chronic diseases, such as primary immunodeficiency, malignancy, rheumatoid arthritis, and asthma.

Is immune system influenced by adenotonsillectomy in children?

Objective: Tonsils and adenoids are lymphoid tissues that are located in the pharynx and play an important role against invading antigens of the upper respiratory tract. The present study analyses serum immunoglobulin levels and peripheral blood (PB) lymphocyte subsets in children, 24–48 h prior to and 4–6 weeks after adenotonsillectomy, in order to determine early effects of adenotonsillectomy on the immune system. Methods: The study population consists of 15 children (aged 4–10 years) who underwent adenotonsillectomy because of adenoidal hypertrophy and chronic tonsillitis and 15 age-matched healthy children without a history of adenotonsillectomy. Serum IgG, IgA and IgM levels were measured by nephelometry. PB lymphocyte subsets were analysed by using monoclonal antibodies and flow cytometry. Results: Children with chronic tonsillitis have increased levels of CD19+ B lymphocytes compared to healthy controls in the pre-operative period. The percentage of B lymphocytes bearing CD23 was found to be significantly higher in patients, most likely representing in vivo B lymphocyte activation due to chronic antigenic stimulation. After the adenotonsillectomy, despite ongoing B lymphocyte activation, CD8+ T lymphocyte levels increased and B cell levels returned to normal. A slight decrease in serum IgG, IgA and IgM levels was detected in the post-operative period compared to prior levels. Conclusion: Adenotonsillectomy performed in children leads to alterations that may reflect a compensatory response of the developing immune system after the removal of the lymphoid tissue in the setting of chronic antigenic stimulation. However, these changes do not cause significant immune deficiency.

The effect of short-course high-dose methylprednisolone on peripheral blood lymphocyte subsets in children with acute leukemia during remission induction treatment

We have previously demonstrated a favorable effect of high-dose steroid in the treatment of children with acute lymphoblastic leukemia (ALL) and acute myeloblastic leukemia (AML). This study was performed to determine the effect of short-course high-dose methylprednisolone (HDMP) treatment on the peripheral blood (PB) T lymphocyte subsets, and blast cells, during remission induction treatment in 23 children with newly diagnosed acute leukemia (16 with ALL, seven with AML). All patients were administered HDMP as a single daily oral dose of 30 mg/kg for the first 4 days of induction therapy. The number of PB lymphocyte subsets (CD3, CD4, CD8, CD16+56, CD45RA, and CD45RO) were determined by flow cytometry before and after 4 days of HDMP treatment. While the number of PB blast cells significantly decreased, the absolute number of T lymphocytes expressing CD3, CD4, CD8, CD45RA and the absolute number of CD16+56 (natural killer) cells increased in all patients. We suggest that the beneficial effects of HDMP in the induction treatment of acute leukemia may occur partly due to an increase in the number of PB T lymphocyte subsets. A study randomly assigning patients to treatment with either conventional therapy or HDMP may provide further information.

Analysis of blood lymphocyte subsets in children living around Chernobyl exposed long-term to low doses of cesium-137 and various doses of iodine-131.

Epidemiological studies have found that children living around Chernobyl have rates of respiratory tract illness that are higher than those seen in the area before the Chernobyl accident. The present study investigates the possible effects of radiation exposure on the composition of peripheral blood lymphocyte subsets in children living around Chernobyl. Two hundred nineteen healthy children and children suffering from recurrent respiratory diseases aged 6-14 years who received both low doses of radiation to the whole body from (137)Cs and various doses of radiation to the thyroid from (131)I as fallout from the accident were assessed 5 (1991) and 8-10 years (1994-1996) after the accident. A total of 148 healthy children and children suffering from recurrent respiratory diseases living in noncontaminated areas were also evaluated as controls. Children with recurrent respiratory diseases who lived around Chernobyl had a significantly lower percentage of T cells and a higher percentage of NK cells compared to control children with recurrent respiratory diseases during the study period. In contrast to the findings in 1991, a significant decrease in the percentage of helper-inducer cells was observed in children with recurrent respiratory diseases in 1994-1996. In contrast to 1991, there is a positive correlation between the percentage of helper-inducer cells, the helper-inducer/cytotoxic-suppressor cell ratio, and the dose of radiation to the thyroid of healthy children from (131)I in 1994-1996. There was a positive correlation between the dose of radiation to the thyroid from (131)I and the percentage of helper-inducer cells in children with recurrent respiratory diseases 5 years (1991) after the accident. Further, the dose of radiation to the thyroid from (131)I correlated negatively with the percentage of T and B cells and positively with the percentage of NK cells in children with recurrent respiratory diseases 8-10 years (1994-1996) after the accident. These results raise the possibility that long-term exposure to low doses of (137)Cs may have altered the composition of the T-cell subsets and NK cells in children with recurrent respiratory diseases. The differences in the composition of the peripheral blood lymphocyte subsets between healthy children and those with recurrent respiratory diseases may be attributed to long-term low-dose exposure of the whole body to radiation from (137)Cs and exposure of the thyroid to radiation from (131)I subsequent to the Chernobyl accident.

Age-related changes in blood lymphocyte subsets of Saudi Arabian healthy children.

The age-related changes in absolute and percentage values of lymphocyte subsets in the peripheral blood of healthy children of different ages (1 month to 13 years) were studied by flow cytometry. The absolute and percentage values for most lymphocyte subpopulations differed substantially with age. Comparisons among age groups from infants through adults revealed progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells increased with age. Within the T-lymphocyte population, the CD8(+) subset increased but the CD4(+) subset decreased, resulting in a declining CD4(+)/CD8(+) ratio. The percentage of B cells declined, but that of NK cells remained unchanged. The percentage of HLA-DR+ T cells increased over time, but their number changed inconsistently. Our findings confirm and extend earlier reports on age-related changes in lymphocyte subpopulations. These data should be useful in the interpretation of disease-related changes, as well as therapy-dependent alterations, in lymphocyte subsets in children of different age groups.

Lymphocyte subset reference ranges in healthy Saudi Arabian children.

In an attempt to establish the reference ranges for lymphocyte subsets in children, the distribution of lymphocyte population-bearing surface markers such as CD3 (T cells), CD19 (B cells), CD4 (T helper/inducer cells), CD8 (T suppressor/cytotoxic cells), and CD16 and/or CD56 on CD3- cells (NK cells) has been studied among healthy Saudi Arabian infants and children. Normal adult blood donors were used for comparison. Anticoagulated peripheral blood was stained with monoclonal antibodies and the lymphocytes were analyzed by flow cytometry for the expression of the above markers. Absolute and percentage values for most lymphocyte populations differed substantially not only between children and adults but also among children from different age groups. Absolute numbers of all the lymphocyte subsets decreased with age from 1 month to 13 years; the median value declined from 4.1 to 1.9 (T cells), 1.6 to 0.6 (B cells), 0.5 to 0.3 (NK cells), 2.7 to 1.0 (CD4+ T cells) and 1.5 to 0.8 x 10(3) cells/mm3 (CD8+ T cells). HLA-DR+ T cell counts changed significantly from 0.3 to 0.2 x 10 (3) cells/mm3 during the same age period. In contrast, the lymphocyte percentage increased in all the subsets except B cells and CD4+ T cells with time. The percentage values increased from 66 to 74 (T cells), 8 to 11 (NK cells), 23 to 39 (CD8+ T cells) and 4 to 9 (HLA-DR+ T cells). The values changed from 24 to 12 and 46 to 39 for B cells and CD4+ T cells, respectively, with age from 1 month to 13 years. The variations in CD4+ and CD8+ T cells resulted in a decrease in CD4+/CD8+ ratio from 2.0 to 1.1 with age. These data should be useful as reference values for lymphocyte subsets in various diseases of infants and children.

Analysis of Blood Lymphocyte Subsets in Children Living on Territory That Received High Amounts of Fallout from Chernobyl Accident

The major lymphocyte subsets in the peripheral blood were assessed in 120 children 6–13 years old living on areas that received high levels of radioactivity as fallout after the Chernobyl nuclear power plant accident. Seventy-one of the children were suffering from recurrent respiratory disease (RRDC) and 49 were not (non-RRDC). As controls, a total of 87 RRDC and non-RRDC living on noncontaminated areas were evaluated. We did not find significant differences in major lymphocyte subsets between the values in non-RRDC living on radionuclide-contaminated areas and noncontaminated areas. However, RRDC living on radionuclide-contaminated areas had a significantly lower percentage of CD3+T and CD3+CD4+T-helper/inducer cells compared to control RRDC. Furthermore, the decrease in percentage of CD3+CD4+cells was more profound in RRDC living in radiation-contaminated settlements with an average summary dose (ASD) Cs-137(134) and Sr-90 for the population >1.0 mSv than in RRDC living in contaminated settlements with an ASD Cs-137(134) and Sr-90 <1.0 mSv. These data indicated that long-time exposure to small doses of radiation could affect the immune system in children living around Chernobyl.

SCE rate and lymphocyte differentiation in children with acute lymphoblastic leukemia and SCE rates of leukemia patients in long-term remission

Sister chromatid exchanges (SCE) and lymphocyte subsets of children with acute lymphoblastic leukemia (ALL) were investigated in children with ALL during chemotherapy and at least 5 years after chemotherapy. The treatment of the new admitted patients followed protocol ALL-BFM-90. Children with ALL at the time of diagnosis showed statistically significant higher SCE frequencies (4.9 +/- 0.77) than healthy controls (3.6 +/- 0.93; p = 0.002). The in vivo effects of cyclophosphamide (CP) resulted in a dramatic increase of the SCE frequency (20.5 +/- 3.76). This increased SCE level of lymphocytes might reflect an instability of DNA or a deficiency of DNA repair capacity. However, immediately one week after the administration of CP, the SCE rate decreased. This decline of SCE frequency correlates with a severe reduction of the absolute numbers of T lymphocytes. The observed reduction of SCE frequency may be due to a depletion of T lymphocytes, or a repair of DNA. The patients in long term remission ( > 5 years) have had the therapy according BFM-83 (9 pat.) and modified 'Pinkel-regime' (2 pat.). No difference was found between the SCE-rate of the patients in remission and of the age-dependent control group. These results might correlate with the low risk for future development of relaps or second malignancy.

The relationship of plasma zinc to lymphocyte subsets in children with chronic upper respiratory tract infections

The relationship of plasma zinc to lymphocyte subsets in children with chronic upper respiratory tract infections

Alterations of lymphocyte subsets in children of diabetic mothers.

To investigate the impact of diabetic mothers on the maturation of the immune system in their offspring, immunophenotypic markers of major lymphocyte subpopulations were evaluated by two-colour flow cytometric analysis in 160 healthy children of diabetic mothers (100 with insulin-dependent diabetes mellitus (IDDM): 48 with gestational diabetes), including 22 neonates, 45 infants aged 8-12 months, 46 children aged 1-2 years, 29 children aged 3-6 years and 18 children aged 7-17 years. Results were compared with 21 neonates of healthy mothers from our hospital and with 110 paediatric subjects of a reference population. In neonates of diabetic mothers, percentages of total lymphocytes (p = 0.044), T and B lymphocytes (p = 0.004, respectively) were significantly decreased compared to our neonates of healthy mothers. By subdividing the group of neonates in offspring of mothers with IDDM (n = 15) or gestational diabetes (n = 7), differences compared to normal neonates were mainly observed in neonates of mothers with IDDM (T lymphocytes: p = 0.006; B lymphocytes: p = 0.008). In cord blood, 45.5% of neonates had antibodies to islet cells, insulin or glutamic acid decarboxylase, most likely transmitted through the placenta of the diabetic mother. No association was found between alterations of lymphocyte subsets and antibody-positivity in cord blood, nor was there any correlation of lymphocyte counts and mean HbA1 during pregnancy, maternal age at delivery, diabetes duration, or neonatal birth weight, respectively. Comparisons among age groups from newborn infants through adolescents revealed higher percentages of total lymphocytes and lower percentages of activated T cells in children of diabetic mothers compared to children of the reference population between the age of 1 to 6 years (67-73% of the cases above and 62-77% below the interquartiles of the reference range, respectively). No significant differences in lymphocyte subpopulations between children of mothers with IDDM diabetes and gestational diabetes have been detected. In addition, there were no abnormalities of lymphocyte subsets in children who are at high risk for the development of IDDM. In summary, we suggest that the observed changes in children of diabetic mothers may reflect a cellular immune reaction to the particular maternal environment, characterized by both an abnormal metabolic state and persisting autoimmunity in the affected mother.

Alterations of lymphocyte subsets in children of diabetic mothers

To investigate the impact of diabetic mothers on the maturation of the immune system in their offspring, immunophenotypic markers of major lymphocyte subpopulations were evaluated by two-colour flow cytometric analysis in 160 healthy children of diabetic mothers (100 with insulin-dependent diabetes mellitus (IDDM); 48 with gestational diabetes), including 22 neonates, 45 infants aged 8–12 months, 46 children aged 1–2 years, 29 children aged 3–6 years and 18 children aged 7–17 years. Results were compared with 21 neonates of healthy mothers from our hospital and with 110 paediatric subjects of a reference population. In neonates of diabetic mothers, percentages of total lymphocytes (p=0.044), T and B lymphocytes (p=0.004, respectively) were significantly decreased compared to our neonates of healthy mothers. By subdividing the group of neonates in offspring of mothers with IDDM (n=15) or gestational diabetes (n=7), differences compared to normal neonates were mainly observed in neonates of mothers with IDDM (T lymphocytes: p=0.006; B lymphocytes: p=0.008). In cord blood, 45.5% of neonates had antibodies to islet cells, insulin or glutamic acid decarboxylase, most likely transmitted through the placenta of the diabetic mother. No association was found between alterations of lymphocyte subsets and antibody-positivity in cord blood, nor was there any correlation of lymphocyte counts and mean HbA1 during pregnancy, maternal age at delivery, diabetes duration, or neonatal birth weight, respectively. Comparisons among age groups from newborn infants through adolescents revealed higher percentages of total lymphocytes and lower percentages of activated T cells in children of diabetic mothers compared to children of the reference population between the age of 1 to 6 years (67–73% of the cases above and 62–77% below the interquartiles of the reference range, respectively). No significant differences in lymphocyte subpopulations between children of mothers with IDDM diabetes and gestational diabetes have been detected. In addition, there were no abnormalities of lymphocyte subsets in children who are at high risk for the development of IDDM. In summary, we suggest that the observed changes in children of diabetic mothers may reflect a cellular immune reaction to the particular maternal environment, characterized by both an abnormal metabolic state and persisting autoimmunity in the affected mother.

Alteration in the Proportion of CD4 T Lymphocytes in a Subgroup of Human Immunodeficiency Virus-Exposed-Uninfected Children

The age-related changes in the proportion of CD4 and CD8 lymphocytes in human immunodeficiency virus (HIV)-seronegative children born to HIV-infected mothers (seroreverters) were compared with the changes in these lymphocyte subsets in children born to seronegative women to assess a possible effect of exposure to HIV without infection. There were 146 seroreverter and 72 seronegative children. The median CD4 and CD8 percentages for each of these two groups of children were compared retrospectively at 3-month intervals from birth through 27 months and at a tenth interval for the time beyond 27 months. The weighted average of the within-subject rate of change of CD4 and CD8 percentages were also compared between the two groups. Finally, for each subject, the proportion of the subject's CD4 percentage assays which were <10th percentile of the entire study population (30%) was calculated, and the distributions of the subject-specific proportions were then compared between the seronegative and seroreverter groups using the Wilcoxon rank sum test. The proportion of CD8 assays <10th percentile (12%) or > 90th percentile (26%) were also computed for each subject, and the distributions of the proportions were compared similarly. . The median CD4 percentage of seroreverter children was lower than that for the seronegative children at every interval from birth through 27 months and for the last interval for values obtained at greater than 27 months, although the comparison was statistically significant only at the 4- to 6-month period. The weighted average of the within-subject rate of change of CD4 percentage was -0.09 and -3.0 per year (P = .04), and of CD8 percentage was 1.3 and 1.0 (P = .67), for the seroreverter and seronegative children, respectively. There were significantly more children in the seroreverter group than in the seronegative group who had repeated assays in which the CD4 percentage was < 10th percentile for age (P < .00005). In addition, there was a subset of 10 seroreverter children (6.8%) who had CD4 percentages < 30% on > 50% of their assays, as compared with only one (1.4%) seronegative child. The proportion of CD8 assays < 10th percentile or > 90th percentile were not significantly different between the two groups of children. The CD4 proportions were persistently lower in the seroreverter than in the seronegative population, although only reaching statistical significance in 1 of 10 3-month intervals. This finding may be due to a subgroup of seroreverter children who have persistently low CD4 lymphocyte percentages.

Lymphocyte Subsets in Healthy Children During the First 5 Years of Life

To assess whether relative and absolute values of CD4 and CD8 lymphocytes and CD4/CD8 ratio change in relation to age, and to estimate the fifth and 95th percentiles for these values in children of various ages. Phenotypic analysis of lymphocyte subsets was performed on blood samples from 208 healthy children, aged 1 through 59 months, using standard flow cytometric techniques. Regression analysis demonstrated that CD4 and CD8 lymphocyte counts declined significantly with advancing age (P less than .000001 and P = .03, respectively). Since CD4 and CD8 counts depend on total lymphocyte count, the percentage of total lymphocytes of each phenotype was also analyzed and demonstrated that the CD4 percentage was highly age dependent (P less than .000001). The CD8 percentage increased with age (P = .0001) but not as much as the CD4 percentage decreased. Median CD4 counts (fifth and 95th percentiles) for children 2 through 3, 4 through 8, 12 through 23, and 24 through 59 months of age were 2.83 (1.46 to 5.11), 2.95 (1.69 to 4.61), 2.07 (1.02 to 3.60), and 1.80 (0.90 to 2.86) x 10(9)/L, respectively. Healthy children's CD4 lymphocyte counts are considerably higher than previously established adult values. These data demonstrate that age is an important consideration in interpretation of lymphocyte subsets in children. This may be especially relevant in children who are infected with the human immunodeficiency virus, where CD4 lymphocyte values play a central role in monitoring disease progression and determining thresholds for medical interventions.

Effect of diet and age on jejunal and circulating lymphocyte subsets in children with coeliac disease: persistence of CD4-8-intraepithelial T cells through treatment.

Monoclonal antibodies were used to determine the relative numbers of T lymphocyte subsets in 61 jejunal biopsies and in peripheral blood of 35 children with coeliac disease, and of 13 healthy controls. The T cell numbers in the lamina propria were unaffected by a change from gluten-free to gluten containing diet in the patients. The number of intraepithelial lymphocytes (where the CD8 cells predominated) were significantly raised in patients taking gluten. Ten to 20% of the patients' intraepithelial CD3 (mature T) cells expressed neither CD8 nor CD4 surface antigens. This CD4 8 T cell population persisted through gluten elimination and challenge. The circulating lymphocyte subsets showed little variation with the diet although there was a marked increase in the proportion (14.9%) of CD4 8 T cells in patients during gluten elimination. In the histologically normal jejunal mucosa from control subjects, the age of the subject showed a positive correlation with villus intraepithelial CD3+ and CD8+ cells, and crypt intraepithelial CD4+ cells. No clear cut effect of age was observed on lamina propria lymphocyte counts of the controls, or on the lymphocyte counts in jejunal mucosa of the coeliac patients. The observed CD3+4-8- lymphocytes may represent activated cells unable to present their surface antigens, or they may be gamma delta-receptor bearing T cells, which could have a significant role in the pathogenesis of coeliac disease.

Lymphocyte Subsets in Children with Aplastic Anemia

Twenty-four patients with aplastic anemia (AA) were evaluated with immunologic studies. Patients with posthepatitis AA had decreased proportions of T4 cells, increased proportions of T8 cells, and decreased T4:T8 ratios. Patients with constitutional AA had varied immunologic findings. There were no significant abnormalities in lymphocyte subsets in patients with idiopathic AA. Of the 12 patients who were treated with antithymocyte globulin (ATG), six (50%) responded. Nine of these patients are living 3-27 months after treatment; three of the nine are transfusion dependent. T-cell subsets were not helpful in predicting the response to ATG. Measurements of other immunologic mediators may be more useful with regard to pathophysiology and prognosis in AA.

Immunogold staining method for the light microscopic detection of leukocyte cell surface antigens with monoclonal antibodies: its application to the enumeration of lymphocyte subpopulations.

Colloidal gold was used as a marker for the light microscopic detection of lymphocyte cell surface antigens with monoclonal antibodies. Suspensions of peripheral blood leukocytes were first incubated with monoclonal mouse antibodies and then with colloidal gold-labeled goat anti-mouse antibodies. The cells were fixed and cytocentrifuge preparations or smears were made. Granulocytes and monocytes were then labeled by the cytochemical staining of their endogenous peroxidase activity. Lymphocytes reacting with the monoclonal antibody had numerous dark granules around the surface membrane. With electron microscopy, these granules appeared as patches of gold particles. This immunogold staining method proved to be a reliable tool for the enumeration of T-lymphocyte subpopulations in peripheral blood. The results were almost identical to those obtained with immunofluorescence microscopy. The procedure can also be applied on small volumes of capillary blood. This constitutes a good microtechnique for the determination of lymphocyte subsets in children.