Two-color immunofluorescence and flow cytometric analysis of peripheral blood lymphocyte subsets in Caucasian and Japanese healthy subjects

Hematologic reference intervals for healthy adult Saudis in Riyadh

BACKGROUND

Laboratory hematological tests are widely used in clinical practice to assess health and disease conditions. Reference ranges provided by laboratory reports are considered the most authoritative medical tools to assist in the decision-making phase. International standards institutes recommend that reference ranges be established for each region.

OBJECTIVES

Provide reference values of routine hematological parameters in Saudi adults according to age and gender.

DESIGN

Cross-sectional SETTING: Central province of Saudi Arabia.

PATIENTS AND METHODS

Apparently healthy Saudi adults were subjected to laboratory testing of routine hematological parameters (full blood count, hemostatic profile, and serum hematinics), after completing a detailed health medical questionnaire.

MAIN OUTCOME MEASURES

Hematological reference values based on the local population.

SAMPLE SIZE AND CHARACTERISTICS

637 after screening 827 potentially healthy Saudi adults with ages ranging from 15 to 65 years.

RESULTS

The reference values of routine hematological parameters for the full population and by gender are presented with 90% CI as the lower and upper limits. Reference ranges mostly differed from universal established ranges shown in textbooks.

CONCLUSION

The reference ranges of routine hematologic parameters for accurate assessment and appropriate management will help improve the routine clinical care of the adult Saudi population.

LIMITATIONS

Difficulty in assessing health status of participants, who could have subclinical illnesses not reflected in the evaluated blood measurement. Lack of ability to eliminate individuals who might be carriers for haemoglobinopathies. Studies with larger sample sizes from different areas of the country are required to achieve a more accurate representation of the whole Saudi population.

CONFLICT OF INTEREST

None.

Incomplete Recovery of CD4 Cell Count, CD4 Percentage, and CD4/CD8 Ratio in Patients With Human Immunodeficiency Virus Infection and Suppressed Viremia During Long-term Antiretroviral Therapy

Background

The extent and duration of long-term recovery of CD4 count, CD4 percentage (CD4%), and CD4/CD8 ratio after initiation of combination antiretroviral therapy (cART) in patients with a suppressed viral load (VL) are largely unknown.

Methods

Patients infected with human immunodeficiency virus type 1 who started cART between January 2004 and January 2012 and showed persistent viral suppression (VL, <200 copies/mL) for ≥4 years were followed up at the AIDS Clinical Center in Tokyo. Change point analysis was used to determine the time point when CD4 count recovery shows a plateau, and a linear mixed model was applied to estimate the CD4 count at this change point.

Results

Data were analyzed from 752 patients (93% male; median age, 38 years; median baseline CD4 cell count, 172/µL [interquartile range CD4%, 13.8%]; CD4/CD8 ratio, 0.23). The median follow-up period was 81.2 months, and 91 patients (12.1%) were followed up for >10 years. Change point analysis showed that CD4 count, CD4%, and CD4/CD8 ratio continued to increase until 78.6, 62.2, and 64.3 months, respectively, with adjusted means of 590/µL (95% confidence interval, 29.5%, and 0.89, respectively, at the change point. Although CD4 counts ≥500/μL were achieved in 73.8% of the study patients, they were not achieved in 48.2% of those with a baseline CD4 count <100/μL. Neither the CD4% nor the CD4/CD8 ratio were normalized in a majority of patients.

Conclusions

The results showed lack of normalization of CD4 count, CD4%, and CD4/CD8 ratio to the levels seen in healthy individuals even after long-term successful cART in patients with a suppressed VL.

Persistent low level Epstein-Barr virus DNAemia in childhood cancer survivors

BACKGROUND

Clinical observation of Epstein-Barr virus (EBV) status has not documented in childhood cancer survivors (CCSs) sustaining long-term remission of malignant diseases. Thus, the aim of this study was to evaluate the EBV status in children with various malignant diseases after they completed their treatments.

PATIENTS AND METHODS

Thirty consecutive children with various malignant diseases previously received treatment at the University of Tsukuba Hospital. Nine cases had acute lymphoblastic leukemia (ALL), 10 had solid tumors, 4 had lymphoma, 4 had CNS tumors, and 3 had acute myeloid leukemia (AML). EBV DNA in 328 whole blood samples were monitored by real-time QPCR for all cases after treatment. Clinical records and laboratory data were also reviewed.

RESULTS

There were 6/30 (20%) cases with continuous detection of EBV DNA while there were 24/30 (80%) cases without continuous EBV DNA. EBV DNAemia was persistently observed in 4/9 (44.4%) cases with ALL and in 2/4 (50%) cases with lymphoma. Persistent EBV DNAemia can be observed for >5 years without any EBV associated symptoms or diseases.

CONCLUSIONS

Childhood cancer survivors have persistent EBV DNAemia more frequently, which is thought to be observed in cases with ALL and lymphoma with higher tendency for >5 years after treatment. Persistent EBV DNAemia is frequent in CCSs aged 5-10 years. Any immunological alteration is speculative in a pathophysiology of persistent EBV DNAemia.

Influence of age, gender and lifestyle in lymphocyte subsets: report from the Spanish Gait-2 Study

INTRODUCTION

Flow cytometry analysis of lymphocyte subsets in peripheral blood is a common technique in diagnostic laboratories. Abnormal values have been identified in prevalent infections, autoimmune disorders and neoplastic diseases. Reference ranges for lymphocyte subsets of a healthy population from Spain are scarce.

METHODS

The study was performed on 319 healthy subjects, aged 4-88 years, from 709 individuals enrolled in the GAIT-2 Project (Genetic Analysis of Idiopathic Thrombophilia). Health status, age, sex, fertility, BMI and lifestyle (physical activity, cigarette smoking and ethanol intake) were assessed using standardized criteria. The percentage of lymphocyte subsets was determined using flow cytometry (Lymphogram™). Percentages of CD3+, CD4+, CD8+, CD19+, CD3-CD56+, CD3+CD4-CD8- double-negative (DN) T cells, CD3+CD4+CD8+ double-positive T cells and the CD4+/CD8+ ratio were recorded for each case.

RESULTS

Children had a significantly higher percentage of CD19+ and DN cells than adults. Women had a significantly higher percentage of CD3+ and CD4+ and a lower percentage of natural killer cells than men. Increases in BMI were inversely associated with the percentage of DN cells. Physical activity increased the percentage of lymphocytes and DN cells. Alcohol consumers had a lower percentage of CD19+ and DN cells, and a higher percentage of CD4+.

CONCLUSION

This study provides reference ranges for lymphocyte subsets of healthy children and adults in a Mediterranean population (Spain) and determines the influence of lifestyle factors on these values.

Age-associated alteration of γδ T-cell repertoire and different profiles of activation-induced death of Vδ1 and Vδ2 T cells

It has been suggested that γδ T cells are involved in certain autoimmune disorders. To establish reference data for clinical studies to explore the role of γδ T cells in autoimmune bone marrow failure syndrome, we examined the γδ T-cell repertoire in 120 healthy Japanese individuals by flow cytometry. The average numbers of T lymphocytes in blood were as follows: 1,084 ± 369 (SD) αβ T cells, 68 ± 44 γδ T cells, 16 ± 12 Vδ1 T cells, and 43 ± 36 Vδ2 T cells (/μl). Absolute numbers of γδ T cells decreased with aging (R = -0.378, P < 0.001). The decrease of γδ T cells was the result of reduction of Vδ2, but not of Vδ1, T cells. Numbers of Vδ2 T cells were significantly higher in male than in female donors (P = 0.007). The Vδ2 T cells but not Vδ1 T cells showed a rapid reduction in cell numbers on mitogen stimulation, which was accompanied by modest down-regulation of Bcl-2 protein expression. These results indicate that age and gender have a major impact on γδ T-cell repertoire in Japanese donors, as well as European and American donors. The age-related decrease of Vδ2 T cells may be explained by their susceptibility to activation-induced cell death.

Hypoxic exercise training promotes antitumour cytotoxicity of natural killer cells in young men

The cytotoxic functions of NKs (natural killer cells) are critical in enabling the immune system to cope efficiently with malignancy. In the present study, we compared how various exercise regimens without/with hypoxia influence phenotypic characteristics of NK subsets and cytotoxicity of NKs to NPCs (nasopharyngeal carcinoma cells). A total of 60 sedentary males were randomly divided into five groups. Each group (n=12) underwent one of five regimens: normoxic (21% O2) control (N-C), hypoxic (15% O2) control (H-C), normoxic exercise (50% maximal work rate under 21% O2; N-E), hypoxic relative exercise (50% maximal heart rate reserve under 15% O2; H-RE) or hypoxic absolute exercise (50% maximal work rate under 15% O2; H-AE) for 30 min/day, 5 days/week for 4 weeks. The results showed that hypoxic exercise regimens increased pulmonary ventilation and tissue oxygen utilization. Moreover, the H-RE regimen resulted in enhanced aerobic fitness at a less intensive training workload in the H-AE regimen. Before each regimen, strenuous exercise elevated NK perforin/granzyme B content and promoted cytotoxicity of NKs to NPCs. However, the percentage of NKs expressing homing (CD11a)/terminally differentiated (CD57)/inhibitory [KLRG1 (killer cell lectin-like receptor G1)] molecules that entered the bloodstream from peripheral tissues increased following this exercise. After 4 weeks, both the H-AE and H-RE regimens produced an up-regulated expression of memory (CD45RO)/activating (NKG2D) molecules and was accompanied by a decrease in CD57/KLRG1 levels on NKs at rest and after strenuous exercise. Furthermore, the two regimens increased resting and exercise NK perforin/granzyme B content and NK-induced phosphatidylserine exposure of NPCs. In contrast, no significant change in the phenotypic characteristics of blood NK subsets or NK-induced NPC apoptosis was observed in the N-C, H-C and N-E regimens. Therefore we conclude that 15% O2 exercise training reduces terminally differentiated NK subsets and up-regulates the expression of activating molecules and cytotoxic granule proteins in NKs, thereby enhancing the capacity of anti-NPC cytotoxicity by NKs. These findings could help to determine effective hypoxic exercise regimens for improving individual aerobic capacity and simultaneously promoting the natural cytotoxicity of NKs.

Flow cytometric characterization of T lymphocyte subsets in the peripheral blood of Chinese rhesus macaques: normal range, age- and sex-related differences

Available data on the normal levels of white blood cell populations in healthy rhesus macaques (Macaca mulatta) originated and living in China is scanty. To obtain such data, blood samples from 150 Chinese rhesus macaques were collected and the normal range of white blood cells and their subsets were analyzed according to age and sex by flow cytometry. CBC data showed that the count of total white blood cells and lymphocytes decreased with age. Phenotypic analysis of CD4 and CD8 expression on CD3+ T lymphocytes showed that the percentage of CD4+ T cells (51.4+/-9.6%), CD4-CD8- T cells (8.5+/-4.1%) and the ratio of CD4+ T to CD8+ T cells (1.26+/-0.55) decreased with age; and the percentage of CD8+ T cells (42.0+/-9.7%), CD4+CD8+ T cells (1.3+/-0.9%) and CD3+ lymphocytes (55.3+/-13.3%) increased with age. However, no statistically significant difference was observed between the male and female groups in most parameters in these monkeys except for the percentage of CD4+CD8+ T cells. This study provided basic information about blood cell count and T lymphocyte subsets in Chinese rhesus macaques. It may be useful for comparative studies using Indian and Chinese rhesus macaques.

CDC staging based on absolute CD4 count and CD4 percentage in an HIV-1-infected Indian population: treatment implications

CD4+ T-cell levels are an important criterion for categorizing HIV-related clinical conditions according to the CDC classification system and are therefore important in the management of HIV by initiating antiretroviral therapy and prophylaxis for opportunistic infections due to HIV among HIV-infected individuals. However, it has been observed that the CD4 counts are affected by the geographical location, race, ethnic origin, age, gender and changes in total and differential leucocyte counts. In the light of this knowledge, we classified 600 HIV seropositive antiretroviral treatment (ART)-naïve Indian individuals belonging to different CDC groups A, B and C on the basis of CDC criteria of both CD4% and CD4 counts and receiver operating characteristic (ROC) curves were generated. Importantly, CDC staging on the basis of CD4% indicated significant clinical implications, requiring an early implementation of effective antiretroviral treatment regimen in HIV-infected individuals deprived of treatment when classified on the basis of CD4 counts.

Lymphocyte immunophenotype reference ranges in healthy Indian adults: implications for management of HIV/AIDS in India

With the advent and application of standard and sensitive flow cytometry methods, it became essential to establish reference intervals in healthy individuals to demarcate between health and disease. A reference range of lymphocyte populations for normal individuals is important in the diagnosis and prognosis of immunodeficiency diseases like AIDS. We tried to accomplish this by studying the values for T lymphocyte subsets for 200 healthy North Indian adults between 18 and 55 years. We obtained the following reference ranges for various T lymphocyte subsets: CD4 count (304-1864 cells/microl with the median of 666 cells/microl), CD4% (17.5-50.6% with the median of 35%), CD8% (14-53% with the median of 32.3%), CD3% (43-89% with the median of 70.5%), and CD4/CD8 ratio (0.04-3.5 with the median of 1.04). Significant variations were observed for normal reference intervals for T lymphocyte subsets according to the race, ethnic origin, age group, and gender.

Immunophenotyping of peripheral blood lymphocytes in Saudi men

Flow cytometry is an important tool for the diagnosis and follow-up of immunodeficiency patients, as well as for patients with leukemia and lymphoma. Lymphocytes and their subsets show variations with race. The aim of this study was to establish reference ranges for lymphocytes and their subsets in an Saudi adult population by using flow cytometry. Blood samples obtained from 209 healthy Saudi men were used for this study. All blood donors were between 18 and 44 years old. Lymphocytes and their subsets were analyzed by flow cytometry, and the absolute and percentage values were calculated. We investigated the expression of T-cell markers (CD3, CD4, and CD8), B cells (CD19), and natural killer cells (CD16 and CD56). The absolute and percent values of each cell subset were compared with published data from different populations by using the Student t test. Reference ranges, each expressed as the mean +/- the standard deviation, were as follows: leukocytes (6,335 +/- 1759), total lymphocytes (2,224 +/- 717), CD3 cells (1,618 +/- 547), CD4 cells (869 +/- 310), CD8 cells (615 +/- 278), CD19 cells (230 +/- 130), and CD3-CD16(+)/CD56+ cells (262 +/- 178). The CD4/CD8 ratio was 1.6 +/- 0.7. Our results for B cells, CD4 cells, and CD8 cells and for the CD4/CD8 ratio fell in between the reported results for Ethiopian and Dutch subjects. Our results were also different from previously reported findings in an Saudi adult population that showed no increase in CD8 T cells. We thus establish here the reference ranges for lymphocytes and their subsets in a large cohort of Saudi men. The CD8 cell count was not abnormally high, as previously reported, and fell in between previous results obtained for African and European populations.

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.

Increase of activated T-cells in BAL fluid of Japanese patients with bronchiolitis obliterans organizing pneumonia and chronic eosinophilic pneumonia

To study the role of T cells in bronchiolitis obliterans organizing pneumonia (BOOP) and chronic eosinophilic pneumonia (CEP) and to examine the influence of differing racial background, T-cell subsets in bronchoalveolar lavage (BAL) fluid (BALF) and in peripheral blood of 8 Japanese patients with idiopathic BOOP and 5 with CEP were compared with those of 15 normal subjects. The BALF pattern in BOOP was characterized by a significantly high number and percentage of lymphocyte and by a low CD4 to CD8 ratio compared with patients with CEP and healthy volunteers. Patients with CEP showed a significantly higher percentage of BALF eosinophils compared with other groups. There was no significant difference in BALF CD4 to CD8 ratio between patients with CEP and volunteers. Two-color analysis of T-cell subsets revealed that CD3+HLA-DR+ cells (activated T cell) in BALF of patients with BOOP and CEP increased significantly compared with volunteers, while BALF CD3+CD25+ cells (interleukin 2 receptor+ T-cell) did not. In addition, BALF CD8+HLA-DR+ cells (activated suppressor/cytotoxic T cell) in patients with BOOP and CD4+HLA-DR+ cells (activated helper T cell) in patients with CEP were significantly higher than levels detected in healthy subjects. The percentage of CD8+CD57+ cells and the number of CD8+CD11b- cells (cytotoxic T cell) in BALF were significantly higher in patients with BOOP compared with patients with CEP and healthy volunteers. There were no significant differences in the expression of peripheral blood T-lymphocyte surface antigens among the groups. These findings indicate that cytotoxic T cells in Japanese patients with idiopathic BOOP and helper T cells in CEP appear in the lungs is consistent with a previous report in Caucasians, supporting the hypothesis that T cells may play an important role in the pathogenesis of these diseases.

Two-color analysis of lymphocyte subsets of bronchoalveolar lavage fluid and peripheral blood in Japanese patients with sarcoidosis

Analysis of T-cell surface markers was carried out in peripheral blood and bronchoalveolar lavage (BAL) fluid of Japanese patients with sarcoidosis to examine the influence of differing racial background. The subjects were 26 untreated patients in whom a diagnosis of active sarcoidosis had recently been established and 9 healthy volunteers, and two-color immunofluorescence analysis was performed. CD3+HLA-DR+ cells, CD4+HLA-DR+ cells, and CD4+CD29+ cells in peripheral blood and BAL fluid were significantly increased in the patients compared with the healthy volunteers, and the mean percentages increased in parallel with the extent of the radiologic stage. The percentage of CD3+HLF-DR+ cells in peripheral blood and lavage fluid also significantly correlated with serum activity of angiotensin-converting enzyme (r = 0.69, p < 0.001; r = 0.61, p < 0.001, respectively). Thus, the evaluation of these antigens' expression is an important clinical approach for the staging of the disease. However, no significant differences were found in CD3+CD25+, CD4+CD45RA+, or CD8+CD11+ cells in either peripheral blood or BAL fluid between the patients and volunteers. Our results indicated that in Japanese patients with sarcoidosis, circulating T cells are activated but CD25+ cells are not increased in peripheral blood and BAL fluid, but there is not a significant association with racial background.