Reference values for peripheral blood lymphocyte subsets in a healthy korean population

Biological aging of different blood cell types

Biological age (BA) captures detrimental age-related changes. The best-known and most-used BA indicators include DNA methylation-based epigenetic clocks and telomere length (TL). The most common biological sample material for epidemiological aging studies, whole blood, is composed of different cell types. We aimed to compare differences in BAs between blood cell types and assessed the BA indicators' cell type-specific associations with chronological age (CA). An analysis of DNA methylation-based BA indicators, including TL, methylation level at cg16867657 in ELOVL2, as well as the Hannum, Horvath, DNAmPhenoAge, and DunedinPACE epigenetic clocks, was performed on 428 biological samples of 12 blood cell types. BA values were different in the majority of the pairwise comparisons between cell types, as well as in comparison to whole blood (p < 0.05). DNAmPhenoAge showed the largest cell type differences, up to 44.5 years and DNA methylation-based TL showed the lowest differences. T cells generally had the "youngest" BA values, with differences across subsets, whereas monocytes had the "oldest" values. All BA indicators, except DunedinPACE, strongly correlated with CA within a cell type. Some differences such as DNAmPhenoAge-difference between naïve CD4 + T cells and monocytes were constant regardless of the blood donor's CA (range 20-80 years), while for DunedinPACE they were not. In conclusion, DNA methylation-based indicators of BA exhibit cell type-specific characteristics. Our results have implications for understanding the molecular mechanisms underlying epigenetic clocks and underscore the importance of considering cell composition when utilizing them as indicators for the success of aging interventions.

Addition of CD14 improves discrimination of lymphocytes in the TBNK phenotyping panel

Peripheral blood lymphocyte phenotyping panels typically include CD45 for discrimination of the lymphocyte population, and fluorophore-conjugated monoclonal antibodies to identify T, B, and Natural Killer (NK) cells. While CD45 combined with side scatter is generally sufficient to clearly distinguish lymphocytes from monocytes in the majority of peripheral blood samples, it is challenging to accurately gate lymphocytes in samples from patients with monocytosis or significant lymphopenia, or from very young infants. Addition of a monocyte marker to lymphocyte phenotyping panels for monocyte exclusion has previously been evaluated for improved discrimination of lymphocytes, albeit largely in healthy donor adult samples. Here we evaluate the effect of the addition of CD14 to a standard lymphocyte phenotyping panel on total lymphocyte, T, B, and NK cell percentages in a predominantly pediatric population of patients under evaluation chiefly for immunodeficiency, immune-depletion, or immune reconstitution. Addition of CD14 to the standard lymphocyte phenotyping improved discrimination of lymphocytes from monocytes, resulted in decreased NK cell percentages, likely because CD16+ and/or CD56+ monocytes were included in the CD56+CD16+ NK cell gate with conventional gating, and although less significant, resulted in an increased percentage of B cells, since relatively larger B cells were likely gated out by more restrictive light scatter gating used with the conventional gating approach. The change in NK and B cell percentages were more pronounced in samples from patients below a year of age, and in patients who were relatively lymphopenic. These data suggest that addition of CD14 to conventional lymphocyte phenotyping panels that utilize CD45 versus side scatter gating results in significant improvement in the accuracy of lymphocyte gating, and accurate quantification of NK and B cells particularly in samples from infants and lymphopenic individuals.

Navigating the nexus among thigh volume, myokine, and immunocytes in older adults with sarcopenia: A retrospective analysis in a male cohort

BACKGROUND

This study investigated the association among thigh volume features, interleukin (IL)-6, and immunocytes in the context of the older people with sarcopenia.

MATERIALS AND METHODS

This study comprised a cohort of 437 older males diagnosed with sarcopenia, and their average age of 70.41 ± 4.86 years. This study involved conducting correlation and multiple linear regression analyses to investigate the connections between thigh volume, IL-6, and immunocytes.

RESULTS

Total thigh volume (TTV) showed positive connections with thigh muscle volume (TMV), natural killer (NK) cells, and CD8 + T cells. TMV had negative associations with thigh fat volume (TFV) and IL6 but displayed positive connections with other factors. IL-6 had adverse associations with all the other variables except for TFV. NK cells showed significant positive relations with all adaptive immune cells, though showing not TFV and IL-6. The CD3+ T cells, CD4+ T cells, CD8+ T cells, and CD19+ B cells exhibited positive correlations with each other including NK cells, though showing not TFV and IL-6. In the regression analysis, TMV exhibited significant positive effects on NK cells (β = 0.304), CD3+ T cells (β = 0.182), CD4+ T cells (β = 0.109), CD8+ T cells (β = 0.226), and CD19+ B cells (β = 0.197). On the other hand, IL-6 had significant negative effects on NK cells (β = -0.292), CD3+ T cells (β = -0.352), CD4+ T cells (β = -0.184), CD8+ T cells (β = -0.387), and CD19+ B cells (β = -0.366).

CONCLUSIONS

This study found that there existed a direct association among thigh muscle with sarcopenia, myokine, and immunocytes.

SIMPLE SUMMARY

The aging process involves the immune system playing a vital role in sarcopenia development, and it is thought that myokines released by skeletal myocytes. However, the exact relationship between TMV, myokines, and immunocytes in older male adults affected by sarcopenia remains unclear. This study found that myokines observed in sarcopenia showed a negative correlation with immunocytes, while muscle mass had a positive correlation with immunocytes. In the meantime, this research delved into the use of a regression model to examine how TMV and myokines individually contribute to explaining the presence of innate and adaptive immunocytes in older individuals with sarcopenia.

The moderating role of circadian gene polymorphisms in the relationship between sleep disturbance and circulating lymphocyte subsets in colorectal cancer patients

AIM

We investigated the impact of sleep disturbance on immune status in colorectal cancer (CRC) patients with consideration of the moderating role of circadian clock gene polymorphisms.

METHODS

A prospective longitudinal study design was used to collect information regarding sleep disturbance. Blood samples for immunologic assays were obtained the day before the first (baseline) and last cycles of 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) chemotherapy. Clinical sleep disturbance was compared between the two-time points using the Pittsburgh Sleep Quality Index (PSQI) global score. We analysed single-nucleotide polymorphisms in rs2278749, rs3749474, rs2291738, rs17031614, and rs2287161. The dependent variables included changes in the percentages of CD4+, CD8+, CD19+, and CD16/56+ lymphocytes between the two-time points. The results were analysed using moderated regression analysis; the p-values were adjusted using the false discovery rate.

RESULTS

Among the 104 patients, no significant dyadic associations were observed between changes in lymphocyte percentages and the PSQI global score. However, the moderated regression analysis revealed five significant associations (rs2287161 with CD8+, rs2278749 and rs2291738 with CD19+, and rs17031614 with CD4+ and CD16/56+ lymphocytes). The inclusion of each interaction resulted in a significant increase (5.7-10.7%) in the variance explained by changes in lymphocyte percentage.

CONCLUSION

Patients with specific circadian gene allele types may be more susceptible to immune dysregulation when experiencing sleep disturbances. Considering that sleep disturbance is a modifiable factor that can impact immune regulation, it is essential to prioritise the management of sleep disturbances in CRC patients receiving FOLFOX chemotherapy.

Biopsy-free profiling of the uterine immune system in patients with recurrent pregnancy loss and unexplained infertility

RESEARCH QUESTION

What are the differences in menstrual blood lymphocytes between controls, patients with recurrent pregnancy loss (RPL) and patients with unexplained infertility (uINF)?

DESIGN

Prospective study including 46 healthy controls, 28 RPL and 11 uINF patients. A feasibility study compared lymphocyte compositions of endometrial biopsies and menstrual blood collected during the first 48 h of menstruation in seven controls. In all patients, peripheral and menstrual blood from the first and subsequent 24 h were analysed separately by flow cytometry, focusing on the main lymphocyte populations and natural killer (NK) cell subsets.

RESULTS

The first 24 h of menstrual blood resembles the uterine immune milieu as tested by endometrial biopsy. RPL patients showed significantly higher menstrual blood CD56+ NK cell numbers than controls (mean ± SD: 31.13 ± 7.52% versus 36.73 ± 5.4%, P = 0.002). Menstrual blood CD56dimCD16bright NK cells within the CD56+ NK cell population were decreased in RPL (16.34 ± 14.65%, P = 0.011) and uINF (15.7 ± 5.91%, P = 0.02) patients versus control (20.42 ± 11.53%). uINF patients had the lowest menstrual blood CD3+ T cell counts (38.81 ± 5.04%, control versus uINF: P = 0.01) and cytotoxicity receptors NKp46 and NKG2D on CD56brightCD16dim cells were higher in uINF (68.12 ± 11.84%, P = 0.006; 45.99 ± 13.83%, P = 0.01, respectively) and RPL (NKp46: 66.21 ± 15.36%, P = 0.009) patients versus controls. RPL and uINF patients had higher peripheral CD56+ NK cell counts versus controls (11.42 ± 4.05%, P = 0.021; 12.86 ± 4.29%, P = 0.009 versus 8.4 ± 3.5%).

CONCLUSIONS

Compared with controls, RPL and uINF patients had a different menstrual blood-NK-subtype profile, indicating an altered cytotoxicity. In future studies, this non-invasive analysis might enable identification and monitoring of patients receiving immunomodulatory medications.

Immune-Ageing Evaluation of Peripheral T and NK Lymphocyte Subsets in Chinese Healthy Adults

Ageing is often accompanied with a decline in immune system function, resulting in immune ageing. Numerous studies have focussed on the changes in different lymphocyte subsets in diseases and immunosenescence. The change in immune phenotype is a key indication of the diseased or healthy status. However, the changes in lymphocyte number and phenotype brought about by ageing have not been comprehensively analysed. Here, we analysed T and natural killer (NK) cell subsets, the phenotype and cell differentiation states in 43,096 healthy individuals, aged 20-88 years, without known diseases. Thirty-six immune parameters were analysed and the reference ranges of these subsets were established in different age groups divided into 5-year intervals. The data were subjected to random forest machine learning for immune-ageing modelling and confirmed using the neural network analysis. Our initial analysis and machine modelling prediction showed that naïve T cells decreased with ageing, whereas central memory T cells (Tcm) and effector memory T cells (Tem) increased cluster of differentiation (CD) 28-associated T cells. This is the largest study to investigate the correlation between age and immune cell function in a Chinese population, and provides insightful differences, suggesting that healthy adults might be considerably influenced by age and sex. The age of a person's immune system might be different from their chronological age. Our immune-ageing modelling study is one of the largest studies to provide insights into 'immune-age' rather than 'biological-age'. Through machine learning, we identified immune factors influencing the most through ageing and built a model for immune-ageing prediction. Our research not only reveals the impact of age on immune parameter differences within the Chinese population, but also provides new insights for monitoring and preventing some diseases in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43657-023-00106-0.

Gender Differences in Oxidative Stress in Relation to Cancer Susceptibility and Survival

Genetic, developmental, biochemical, and environmental variables interact intricately to produce sex differences. The significance of sex differences in cancer susceptibility is being clarified by numerous studies. Epidemiological research and cancer registries have revealed over the past few years that there are definite sex variations in cancer incidence, progression, and survival. However, oxidative stress and mitochondrial dysfunction also have a significant impact on the response to treatment of neoplastic diseases. Young women may be more protected from cancer than men because most of the proteins implicated in the regulation of redox state and mitochondrial function are under the control of sexual hormones. In this review, we describe how sexual hormones control the activity of antioxidant enzymes and mitochondria, as well as how they affect several neoplastic diseases. The molecular pathways that underlie the gender-related discrepancies in cancer that have been identified may be better understood, which may lead to more effective precision medicine and vital information on treatment options for both males and females with neoplastic illnesses.

Assessment of immune cell profiles among post-menopausal women in the Women's Health Initiative using DNA methylation-based methods

BACKGROUND

Over the past decade, DNA methylation (DNAm)-based deconvolution methods that leverage cell-specific DNAm markers of immune cell types have been developed to provide accurate estimates of the proportions of leukocytes in peripheral blood. Immune cell phenotyping using DNAm markers, termed immunomethylomics or methylation cytometry, offers a solution for determining the body's immune cell landscape that does not require fresh blood and is scalable to large sample sizes. Despite significant advances in DNAm-based deconvolution, references at the population level are needed for clinical and research interpretation of these additional immune layers. Here we aim to provide some references for immune populations in a group of multi-ethnic post-menopausal American women.

RESULTS

We applied DNAm-based deconvolution to a large sample of post-menopausal women enrolled in the Women's Health Initiative (baseline, N = 58) or the ancillary Long Life Study (WHI-LLS, N = 1237) to determine the reference ranges of 58 immune parameters, including proportions and absolute counts for 19 leukocyte subsets and 20 derived cell ratios. Participants were 50-94 years old at the time of blood draw, and N = 898 (69.3%) self-identified as White. Using linear regression models, we observed significant associations between age at blood draw and absolute counts and proportions of naïve B, memory CD4+, naïve CD4+, naïve CD8+, memory CD8+ memory, neutrophils, and natural killer cells. We also assessed the same immune profiles in a subset of paired longitudinal samples collected 14-18 years apart across N = 52 participants. Our results demonstrate high inter-individual variability in rates of change of leukocyte subsets over this time. And, when conducting paired t tests to test the difference in counts and proportions between the baseline visit and LLS visit, there were significant changes in naïve B, memory CD4+, naïve CD4+, naïve CD8+, memory CD8+ cells and neutrophils, similar to the results seen when analyzing the association with age in the entire cohort.

CONCLUSIONS

Here, we show that derived cell counts largely reflect the immune profile associated with proportions and that these novel methods replicate the known immune profiles associated with age. Further, we demonstrate the value this methylation cytometry approach can add as a potential application in epidemiological studies.

Sex differences in markers of oxidation and inflammation. Implications for ageing

Sexual dimorphism is a key factor to consider in the ageing process given the impact that it has on life expectancy. The oxidative-inflammatory theory of ageing states that the ageing process is the result of the establishment of oxidative stress which, due to the interplay of the immune system, translates into inflammatory stress, and that both processes are responsible for the damage and loss of function of an organism. We show that there are relevant gender differences in a number of oxidative and inflammatory markers and propose that they may account for the differential lifespan between sexes, given that males display, in general, higher oxidation and basal inflammation. In addition, we explain the significant role of circulating cell-free DNA as a marker of oxidative damage and an inductor of inflammation, connecting both processes and having the potential to become a useful ageing marker. Finally, we discuss how oxidative and inflammatory changes take place differentially with ageing in each sex, which could also have an impact on the sex-differential lifespan. Further research including sex as an essential variable is needed to understand the grounds of sex differences in ageing and to better comprehend ageing itself.

Age- and Sex-Matched Normal Leukocyte Subset Ranges in the General Population Defined with the EuroFlow Lymphocyte Screening Tube (LST) for Monoclonal B-Cell Lymphocytosis (MBL) vs. Non-MBL Subjects

Reference ranges of blood-circulating leukocyte populations by, e.g., age and sex, are required for monitoring immune-cell kinetics. Most previous reports in which flow cytometry has been used to define the reference ranges for leukocyte counts included a limited number of donors and/or cell populations and/or did not consider age and sex simultaneously. Moreover, other factors not previously considered in the definition of normal ranges, such as the presence of chronic-lymphocytic-leukemia (CLL)-like low-count monoclonal B-cell lymphocytosis (MBLlo), might also be associated with an altered distribution of leukocytes in blood in association with an immunodeficiency and increased risk of infection and cancer. Here, we established reference cell-count ranges for the major populations of leukocytes in blood of non-MBL and MBLlo adult Caucasians matched by age and sex using the EuroFlow Lymphocyte Screening Tube (LST). A total of 706 Caucasian adult donors—622 non-MBL and 84 MBLlo—were recruited from the general population. Among non-MBL donors, the total leukocyte, neutrophil, basophil dendritic cell and monocyte counts remained stable through adulthood, while the absolute numbers of T- and B-cell populations and plasma cells decreased with age. The number of eosinophils and NK-cell increased over time, with clear differences according to sex for certain age ranges. In MBLlo subjects, few differences in the absolute cell counts by age (vs. non-MBL) were observed, and MBLlo men and women showed similar trends to non-MBL subjects except for the B-cell count drop observed in >70 y-men, which was more pronounced in MBLlo vs. non-MBL controls. Building robust age- and sex-matched reference ranges for the most relevant immune-cell populations in the blood of non-MBL donors is essential to appropriately identify an altered immune status in different clinical settings and highlight the altered immune-cell profiles of MBLlo subjects.

Comparison of the deep immune profiling of B cell subsets between healthy adults and Sjögren's syndrome

OBJECTIVES

Detailed analysis targeting B cell subgroups was considered crucial in monitoring autoimmune diseases and treatment responses. Thus, precisely describing the phenotypes of B cell differentiation and their variation in primary Sjögren's syndrome (pSS) is particularly needed.

METHODS

To characterize the proportions and absolute counts of B cell subsets, peripheral blood from 114 healthy adults of China (age range: 19-73 years) and 55 patients with pSS were performed by flow cytometry and CD19, CD20, CD24, CD27, CD38 and IgD were used as surface markers to identify B cell mature process. Age- and gender-stratified analyses were then carried out to improve the interpretation of B cell subsets.

RESULTS

The assessments from healthy adults showed that the proportion of naive B cells presented a significant increase with age. A reversal trend was noted that the percentage of B10 decreased markedly with age. In addition, analysis based on gender showed that the relative percentage and number of naive B cells were higher in females than in males whereas the proportions of switched memory B cells and B10 cells were decreased in female. Patients with pSS exhibited a significant expansion in naïve B cells and unswitched memory B cells, accompanied with decreased switched memory B cells and B10 cells, which were identified to be associated with autoantibody production.

CONCLUSIONS

Our study presented a reliable analysis by flow cytometry to cover the principal B cell subtypes. These different stages of B lymphocytes may have implications for evaluating the activation of pSS and other autoimmune diseases and treatment efficacy.KEY MESSAGESB cell subsets play a pivotal role in the pathogenesis of primary Sjögren's syndrome (pSS) and other autoimmune diseases. A practical and accurate flow cytometry method to profile B cell phenotypes in peripheral blood of healthy adults is especially essential.Additionally, we presented reliable reference ranges for B cell subsets in regards to the local population. Age- and gender-related analyses are available to better understand their influence in immune status and treatment outcome.The distribution of B-cell subsets is found substantially altered in patients with pSS, bringing novel avenues for pSS research in the future.

Healthy Ageing Reflected in Innate and Adaptive Immune Parameters

Purpose

The aim of the paper is to establish and quantify the relation between healthy ageing and the innate and adaptive immune parameters as indicators of age-related diseases.

Patients

In order to observe the immunological changes that occur according to age, several humoral and cellular immune parameters were investigated for 288 healthy donors (30-80 years). Subjects' selection was done using clinical, biochemical and immunological parameters of inclusion/exclusion criteria from SENIEUR protocol.

Results

Age-related changes were observed for both humoral and cellular immune parameters. Lymphocyte immunophenotyping revealed several significant differences in the distribution of cells, both intra- and inter-age groups, namely decreased values of T-CD3⁺, T-CD8⁺ and NK cells, and elevated values for T-CD4⁺, T-CD4⁺/T-CD8⁺ ratio and B cells. The percentages of unstimulated neutrophils that show basal oxidative activity and the intensity of this activity had an increasing tendency age-related. The percentage of N-Formyl-Methionyl-Leucyl-Phenylalanine stimulated neutrophils clearly decreases with age, and is associated with an increasing intensity of oxidative activity. Our data also have shown an increased percentage of oxidative neutrophils after phorbol 12-myristate 13-acetate stimulation and an elevated oxidative activity with age.

Conclusion

Overall healthy ageing is governed by some immune-related deregulations that account for immune exhaustion due to numerous developed immune processes during a life-time and the age-related diseases.

Accentuated Peripheral Blood NK Cytotoxicity Forms an Unfavorable Background for Embryo Implantation and Gestation

Problem Many studies have demonstrated the negative impact of high rates of NK cytotoxicity (NKc) on reproductive processes, but there is no agreement as to the appropriateness and feasibility of using the NKc for routine diagnostic in IVF patients. This study conducted a retrospective analysis of embryo transfer (ET) success rates and live birth rates (LBR) in patients with different NKc values. Method of study 1854 cycles of ET were selected and divided into three groups according to NKc levels, and randomized by anamnesis and age: normal (nNKc, n = 871), elevated (eNKc, n = 759), and reduced NKc (rNKc, n = 123). ET with donors’ embryos (n = 101) were analyzed separately. NKc-to-K562 was measured in PBMC (peripheral blood mononuclear cells) by flow cytometry before ET. The patients did not obtain any additional treatments. Results Patients with eNKc, in addition to having reduced clinical pregnancy rates (OR1.59, p < 0.0001), had increased levels of subsequent pregnancy failures (OR2.545, p < 0.0001) when compared to nNKc patients. As a result, patients with eNKc had almost half the LBR than patients with nNKc (OR2.2, p < 0.0001). In patients with rNKc, LBR was also lowered. eNKc was equally unfavorable for implantation and delivery in cryo- or fresh cycles. Markedly, eNKc was much more unfavorable for reproduction than slightly elevated NKc. The donor’s embryos were implanted irrespective of the recipient’s NKc levels, but the later stages of pregnancy were worse in patients with eNKc. Conclusions Our findings highlighted the negative impact of high levels of NK cytotoxicity on pregnancy outcomes.

Establishment of the reference intervals of lymphocyte subsets for healthy Chinese Han adults and its influencing factors

Background

Cellular immune monitoring is becoming more critical in the clinic, but its application has not yet become sufficiently widespread. One reason may be the different reference intervals among clinical laboratories due to several factors. Percentage and number of lymphocyte subsets are standard indicators of cellular immune detection. The present study aimed to establish standardized reference intervals of lymphocyte subsets in the healthy Chinese Han adult population and examine such influencing factors as age, gender, region, and measurement instruments.

Methods

A total of 496 healthy Chinese Han people aged 18–59 years from 3 China Mainland regions (north, east, and south) were enrolled. The sample of each center was simultaneously examined by three flow cytometers (FACSCanto^TMII, FACSLyric^TM, and FACSCalibur^TM). A single-platform flow cytometry-based absolute count technique was used to quantify the percentage and number of each lymphocyte subset. The flow cytometry results were analyzed by variance analysis and Z test to determine the influence of age, gender, and instruments on lymphocyte subsets.

Results

Multi-center, age-specific, and gender-specific reference intervals of healthy Chinese Han adults’ lymphocyte subsets were established. There was no statistical difference in the results from the three flow cytometers. Gender affected the results of CD4⁺ (%) and the absolute count of CD3⁻CD16⁺CD56⁺, where CD4⁺ (%) was higher in women, and the absolute count of CD3⁻CD16⁺CD56⁺ was higher in men. Age mainly affected the CD4⁺/CD8⁺ ratio, which was statistically higher in groups aged over 40 years; the percentage and number of CD3⁻CD19⁺ were more elevated in age groups below 30 years; however, the difference was not statistically significant.

Conclusions

This study established the reference intervals of lymphocyte subsets for healthy Chinese Han adult populations under the standardized methods. This study was the first nationwide study in China to use a flow cytometry-based single-platform method to establish the reference intervals of lymphocyte subsets of the healthy Chinese Han adult population. Gender and age were shown to influence the results of lymphocyte subsets.

A Critical Review on the Standardization and Quality Assessment of Nonfunctional Laboratory Tests Frequently Used to Identify Inborn Errors of Immunity

Inborn errors of immunity (IEI), which were previously termed primary immunodeficiency diseases, represent a large and growing heterogeneous group of diseases that are mostly monogenic. In addition to increased susceptibility to infections, other clinical phenotypes have recently been associated with IEI, such as autoimmune disorders, severe allergies, autoinflammatory disorders, benign lymphoproliferative diseases, and malignant manifestations. The IUIS 2019 classification comprises 430 distinct defects that, although rare individually, represent a group affecting a significant number of patients, with an overall prevalence of 1:1,200-2,000 in the general population. Early IEI diagnosis is critical for appropriate therapy and genetic counseling, however, this process is deeply dependent on accurate laboratory tests. Despite the striking importance of laboratory data for clinical immunologists, several IEI-relevant immunoassays still lack standardization, including standardized protocols, reference materials, and external quality assessment programs. Moreover, well-established reference values mostly remain to be determined, especially for early ages, when the most severe conditions manifest and diagnosis is critical for patient survival. In this article, we intend to approach the issue of standardization and quality control of the nonfunctional diagnostic tests used for IEI, focusing on those frequently utilized in clinical practice. Herein, we will focus on discussing the issues of nonfunctional immunoassays (flow cytometry, enzyme-linked immunosorbent assays, and turbidimetry/nephelometry, among others), as defined by the pure quantification of proteins or cell subsets without cell activation or cell culture-based methods.

Immunosenescence evaluation of peripheral blood lymphocyte subsets in 957 healthy adults from 20 to 95 years old

Immunosenescence is characterized by an age-related decline in immune system function. Major efforts have been made to identify changes in peripheral blood lymphocyte subsets accompanying immunosenescence in elderly adults. However, the change trends of some lymphocyte subsets with age are still controversial, and populations of advanced ages, such as people in their 80s or 90s, have not yet been thoroughly investigated. To provide further insight, we recruited 957 healthy donors without certain diseases with ages ranging from 20 to 95 years. Peripheral lymphocyte subsets, including T cells, CD4 T cells, CD8 T cells, B cells and NK cells, and the CD4/CD8 ratio were measured by flow cytometry. Additionally, regulatory CD4 T cells with inhibitory functions marked by CD3⁺CD4⁺CD25^hi and the expression of the costimulatory molecule CD28 on CD8 T cells were evaluated. Sex was considered at the same time. The data indicated that in elderly people, peripheral T (p < 0.001), CD4 T (p < 0.001) and B (p < 0.001) lymphocyte subsets decreased, but the NK cell population (p < 0.001) increased. More regulatory CD4 T cells may imply stronger inhibition in the elderly population. The decreased CD28 expression with age in females verified CD28 to be an immunosenescence marker and the sharply decreased CD28 expression after 75 years in males indicated a rapid immunosenescence at the late life span of the male populations. In addition, our study established reference values for peripheral lymphocyte subsets at different age stages in males and females, which are urgently needed for the clinical management and treatment of geriatric diseases.

Percentage of residual B cells after 2 weeks of rituximab treatment predicts the improvement of systemic sclerosis-associated interstitial lung disease

The benefit of rituximab (RTX) for systemic sclerosis-associated interstitial lung disease (SSc-ILD) has been shown in previous clinical trials. However, predictors of RTX efficacy have not been clarified. We investigated whether B-cell responsiveness to RTX is related to therapeutic effect. Ten SSc-ILD patients treated with RTX in an independent clinical trial (Japan Registry of Clinical Trials, jRCTs031180373) were included in this analysis. Peripheral B-cell counts were examined retrospectively before RTX administration (baseline) and at 2, 4, 12, and 24 weeks after the first RTX administration, along with percent-predicted forced vital capacity (%FVC) before and 24 weeks after RTX treatment. Relative to baseline, the percentage of residual peripheral blood B cells at 2 weeks after RTX was negatively correlated with the %FVC improvement at the 24-week assessment (r = -0.41, p = 0.04). In the subgroup with less than 5% B-cell persistence at week 2, %FVC at the 24-week assessment was significantly improved compared to baseline (p = 0.02). In another subgroup with more than 5% residual B cells, %FVC was not significantly different after 24 weeks compared to baseline (p = 0.41). In conclusion, the removal rate of B cells after 2 weeks of RTX treatment may be a useful surrogate marker of subsequent SSc-ILD improvement.

Variation of B cell subsets with age in healthy Malawians

Although a number of previous studies have shown that different lymphocyte subsets, including B cells, vary with age, how different B cell subsets vary with age in Malawian population has not been shown before. We recruited Malawian participants of different ages and analyzed their venous blood samples for different B cell subsets. We found that both percentage and absolute counts of B cells varied with age peaking in the 7 to 12 months age group. Proportion of naïve B cells was highest in neonates and decreased with age whereas the percentage of memory B cells was lowest in neonates and increased with age. When we zeroed in on the age band within which the proportion of B cells was highest, both classical and activated memory B cells increased with age and the naïve followed the opposite trend. These results provide additional knowledge in our understanding of the dynamics of B cell subsets in individuals of a specific ethnicity as they age.

Characteristics of and reference ranges for peripheral blood lymphocytes and CD4 T cell subsets in healthy adults in Shanxi Province, North China

Objective

To guide clinical decision making, race-, age- and gender-specific reference ranges for lymphocytes and CD4+ T-cell subsets are required.

Methods

Single platform flow cytometry to determine reference intervals for lymphocyte subpopulations and CD4+ T-cell subsets in 196 healthy Han Chinese adults.

Results

The frequencies and absolute numbers of B cells were slightly lower in Han Chinese individuals of the Shanxi region than in individuals from Hong Kong, Germany and Singapore, while percentages and absolute numbers of NK cells were slightly higher compared with individuals from Hong Kong. CD4+/CD8+ T-cell ratios, CD4+ T cell percentages and Th2 cell counts were higher, while frequencies and numbers of CD8+ T cells, numbers of NK cells and percentages of Th1 cells were lower, in females compared with males. CD4+ T cell percentages, CD4+/CD8+ T-cell ratios, numbers of CD8+ T cells and Treg cells, and Th17/Treg cell ratios differed by age.

Conclusion

We established lymphocyte and CD4+ T-cell subset reference intervals for healthy Han Chinese adults of the Shanxi region. Ethnicity, gender and age affected lymphocyte subset composition.

Natural killer frequency determines natural killer cytotoxicity directly in accentuated zones and indirectly in "moderate-to-normal frequency" segment

Natural killer (NK) frequency and NK cytotoxicity (NKc) are key determining factors of a clinical outcome. In our previous study, we showed the prognostic clinical significance of immune parameters when they are beyond the optimal range (accentuated). In this study, we attempted to explain the disparity of accentuated but physiologically and immunologically normal NK parameters that might serve as negative clinical prognostics indications of failed pregnancies. We have analyzed NK%, NKc levels, and their reciprocal correlation in 2,804 patients with reproductive failures. In the entire clinical population, NK% correlates with NKc. Interestingly, we found this relationship to be strongly dependent on NK level's status. NK%-NKc correlation was the strongest (r = 0.2021, p < 0.0001) in a patient group with high NK% (> 17.5%). Patients with NK% between 15-17.5% manifested lower but still significant correlation NK%-NKc (r = 0.1213, p = 0.0155). Additionally, significant correlation (r = 0.2689, p < < 0.0001) between NK% and NKc was observed in a group of patients with NK levels < 7% (1.7-7%). While patients' groups with NK% (7-15%) did not reveal NK%-NKc association. This led us to hypothesize that the qualitative-quantitative status of NK population is responsible for their cytotoxic activity. Consistent with our hypothesis, the "balanced zone" NK% is tightly controlled, and thus does not correlate directly with NKc. In contrast, the "accentuated zones" of NK% escape this control and directly affecting NKc. Demonstrated phenomena supports our idea about the clinical significance of immune accentuation and explains its novel physiological role.

Different Background: Natural Killer Cell Profiles in Secondary versus Primary Recurrent Pregnancy Loss

(1) Background: Prior studies suggested a significant impact of previous live births on peripheral natural killer cells (pNK) in patients with recurrent pregnancy loss (RPL). Patients with primary RPL (pRPL, no live birth) showed higher numbers of pNK than secondary RPL patients (sRPL, ≥ 1 live birth). (2) Methods: To further determine immunological differences between RPL patients and controls, we analysed pNK subpopulations and activation markers in pRPL (n = 47), sRPL (n = 24) and controls with previous live birth (sCtrl, n = 25) and nullipara (pCtrl, n = 60) within a prospective study. Percentages and numbers of CD56dimCD16bright cells, subpopulations and activation markers (CD57+, CD62L+, NKG2D+, NKp46+) were measured in non-pregnant RPL patients and n = 85 controls (n = 60 pCtrl, n = 25 sCtrl) in the mid-luteal phase by flow cytometry. (3) Results: Compared to sRPL patients, sCtrls showed higher CD56+ and CD56dimCD16bright numbers. Further, sRPL patients showed lower numbers of CD56dimCD16brightNKG2D+ and CD56dimCD16brightNKp46+ than sCtrls. (4) Conclusion: We suggest a chronic immune stimulation leading to a lower NK-cell count in sRPL patients with a lower NK cytotoxicity. This underlines the necessity to investigate pNK subpopulations as well as pRPL and sRPL separately to delineate the immune alterations in RPL.

Clinical complications and their management in a child with ataxia-telangiectasia (A-T): A case report study

Ataxia-telangiectasia (A-T) is known as an uncommon autosomal recessive disorder associated with recurrent infections and other clinical complications. The management of its complications can improve life quality of patients.

The unique characteristic in peripheral immune cells in patients with advanced hepatocellular carcinoma

BACKGROUND/PURPOSE

Recent progress in cancer immunology provides more insight in immune evasion of cancer cells. Cancer cells may achieve immune evasion through several ways including ineffective antigen presentation, T cell checkpoint utilization, immunosuppressive cytokines secretion and immunosuppressive cells recruitment. However, few literatures mentioned about the change of peripheral blood immune cells in advanced hepatocellular carcinoma (HCC) patients. To answer this question, we initiated a pilot study through detailed flow cytometry.

METHODS

We enrolled patients with advanced HCC patients who had informed consent to the collection of their peripheral blood. We also recruited healthy individuals for the control group. Using flow cytometry, we analyzed lymphocyte subclasses and the PD-1 or PD-L1 positivity of immune cells in peripheral blood from HCC patients and healthy individuals.

RESULTS

Twenty-four HCC patients were enrolled and twenty healthy individuals were enrolled. Most of the HCC patients were HBV carrier (58.3%), and the mean age was 61 years old. Among 55 immune cell parameters we examined in peripheral blood, 16 were significantly different between advanced HCC patients and healthy individuals by univariate analysis. Multivariate analysis was then conducted by fitting logistic regression model and showed that CD69^-CD25^- Naïve CD4αβT cell percentage and dendritic cell percentage can reasonably predict the advanced HCC status from peripheral blood. By our regression model, the adjusted generalized R2 = 0.918 and the estimated area under the Receiver Operating Characteristic (ROC) curve was 0.99.

CONCLUSION

CD69^-CD25^- Naïve CD4αβT cell percentage and dendritic cell percentage in peripheral blood are highly correlated with the advanced HCC status. The change may result from immune evasion initiated by hepatocellular carcinoma cells and further investigation is warranted. Validation study is ongoing and this mechanism may be utilized to treat advanced HCC patient in the future.

Characteristics and reference ranges of CD4+T cell subpopulations among healthy adult Han Chinese in Shanxi Province, North China

BACKGROUND

Immunophenotyping of blood lymphocytes is an essential tool to evaluate the immune function of patients with immunodeficiency or autoimmunity. Predominately identified CD4⁺T cell subsets, Th1, Th2, Th17, as well as regulatory T (Treg) cells, play crucial roles in several immunological and pathological conditions. Considering the variations in cell counts among populations and ethnicities, specific CD4⁺T cell subset reference values need to be locally established to enable meaningful comparisons and accurate data interpretation in clinical and research settings. Therefore, the aim of this study was to establish distributions and reference ranges for blood CD4⁺T cell subpopulations in age- and sex-balanced healthy adults of a Han Chinese population in Shanxi Province, North China.

METHODS

Peripheral blood CD4⁺T cell subsets were examined in 150 healthy volunteers (75 males, 75 females) aged 20-70 years with a four-color FACSCalibur flow cytometer.

RESULTS

Reference value percentages (absolute counts, cells/μl) were defined as 95% of the population for cell types as follows: CD4⁺T, 23.78-51.07 (360-1127); Th1, 0.43-39.62 (2.64-276.21); Th2, 0.27-3.57 (1.80-27.14); Th17, 0.22-2.62 (1.10-19.54); and Treg, 2.17-7.94 (13.47-64.58). The ranges for the Th1:Th2 and Th17:Treg ratios were 0.59-52.37 and 0.04-0.76, respectively. Notably, a significant increase was observed in the values of Treg cells in older individuals, and the numbers of Treg cells in females also tended to decrease when compared to those in males. Therefore, we established the distribution and reference range of CD4⁺T cell subsets based on age and sex, demonstrating the lowest values of Treg cells in younger females.

CONCLUSIONS

Collectively, our data provide population-, age-, and sex-specific distributions and reference ranges of circulating CD4⁺T cell subpopulations, which can be adopted to guide clinical decisions and interpretation of immunophenotyping data in the Han Chinese population in Taiyuan, Shanxi Province, China. In addition, the low expression of peripheral Treg cells in younger females may be associated with the predisposition of females to autoimmune diseases.

Outcomes of Haploidentical Stem Cell Transplantation using Total Body Irradiation (600 cGy) and Fludarabine with Antithymocyte Globulin in Adult Patients with Severe Aplastic Anemia: A Prospective Phase II Study

The aim of this study was to verify the feasibility of rabbit antithymocyte globulin (ATG; 5 mg/kg) in combination with 600 cGy of fractionated total body irradiation (fTBI; 3 doses of 200 cGy) and fludarabine (Flu; 150 mg/m²) as a conditioning regimen for haploidentical stem cell transplantation from a related mismatched donor (haplo-SCT) in adult patients with severe aplastic anemia (SAA). We analyzed 47 consecutive patients who underwent haplo-SCT, including 24 patients from our previous pilot report. The median age was 36.0 years (range, 17 to 61 years), and 25 patients (53%) were very severe aplastic anemia (VSAA) at transplantation. All patients achieved primary engraftment. The cumulative incidence of grade ≥II acute graft-versus-host disease (GVHD) and chronic moderate or greater GVHD was 27.7% at 100 days and 13.5% at 3 years, respectively. With a median follow-up of 32.3 months, the 3-year probability of overall survival and failure-free survival was 91.0% and 88.6%, respectively. The 3-year GVHD- and failure-free survival (GFFS) was 71.6%. Offspring donor and lower comorbidity index were independent factors correlated with higher GFFS in multivariate analysis. In conclusion, the outcomes of haplo-SCT with fTBI 600 cGy/Flu/ATG-5 indicate that haplo-SCT can be an effective alternative option when a fully matched donor is not available or a patient with VSAA needs an urgent transplantation.

Combination of lymphocyte number and function in evaluating host immunity

Accurate monitoring of host immunity is hampered by the flaws of conventional tests. The relationship between lymphocyte number and function is unknown. The function of lymphocytes was analyzed based on IFN-γ secretion assay. Lymphocyte number and function was investigated in individuals under various states. The number of CD4⁺ and CD8⁺ T cells was gradually decreased, whereas the function of them was gradually increased with increasing age. A significantly negative correlation existed between the number and function of both CD4⁺ and CD8⁺ T cells. Differently, both the number and function of NK cells are maintained at a high level after birth. Staying up all night was found to impair the function of CD4⁺, CD8⁺ T cells, or NK cells. Lymphocyte number and function were both decreased in patients with immunosuppressive conditions or opportunistic infections, while the opposite phenomenon was observed in patients with some autoimmune diseases (except for NK cells). In kidney transplant recipients, the number and function of CD4⁺ and CD8⁺ T cells were increased or decreased when rejection or infection occurred. We demonstrated that evaluation of host immunity based on combination of lymphocyte number and function plays an important role in the diagnosis, treatment, and prognosis of diseases.

The impact of previous live births on peripheral and uterine natural killer cells in patients with recurrent miscarriage

BACKGROUND

Peripheral and uterine natural killer cells (pNK and uNK cells) are key players in the establishment and maintenance of pregnancy and are disturbed in patients with recurrent miscarriage (RM). Different immunologic risk factors have been proposed between patients with primary RM (pRM, no previous live birth) and secondary RM (sRM, ≥ 1 previous live birth). However, so far, the study populations mainly consisted of small subgroups. Therefore, we aimed to analyse pNK and uNK cells in a large, well defined study population within a prospective study.

METHODS

In total, n = 575 RM patients (n = 393 pRM, n = 182 sRM) were screened according to a standard protocol for established risk factors as well as pNK and uNK cells. Peripheral blood levels of CD45⁺CD3^-CD56⁺CD16⁺ NK cells were determined by flow cytometry and uterine CD56⁺ NK cells by immunohistochemistry in mid-luteal non-pregnant RM patients. Exclusion of patients with ≥1 established risk factor revealed n = 248 idiopathic RM patients (iRM, n = 167 primary iRM (ipRM), n = 81 secondary iRM (isRM)).

RESULTS

Patients with pRM and ipRM showed significant higher absolute numbers and percentages of pNK cells compared to sRM and isRM patients (pRM/ipRM vs sRM/isRM, mean ± SD /μl: 239.1 ± 118.7/244.9 ± 112.9 vs 205.1 ± 107.9/206.0 ± 105.6, p = 0.004/ p = 0.009; mean ± SD %: 12.4 ± 5.5/12.8 ± 5.4 vs 11.1 ± 4.6/11.1 ± 4.3, p = 0.001; p = 0.002). Only patients with isRM showed significantly higher uNK levels compared to patients with ipRM (mean ± SD /mm² 288.4 ± 239.3 vs 218.2 ± 184.5, p = 0.044).

CONCLUSIONS

The demonstrated differences in pNK and uNK cells in RM patients depending on previous live birth might indicate differences in NK cell recruitment and potentially different underlying immune disorders between pRM and sRM. As there is an overlap in the distribution of the NK cell results, further studies with focus on NK cell function are needed in order to clearly identify RM patients with distinct immune abnormalities. The clinical relevance of our findings should be interpreted cautiously until specificity and sensitivity are further evaluated.

Comparable Outcome with a Faster Engraftment of Optimized Haploidentical Hematopoietic Stem Cell Transplantation Compared with Transplantations from Other Donor Types in Pediatric Acquired Aplastic Anemia

Haploidentical family donors have been used as an alternative source in hematopoietic cell transplantation for patients with severe aplastic anemia. We evaluated and compared the outcomes of transplantation in pediatric acquired severe aplastic anemia based on donor type. Sixty-seven patients who underwent transplantation between 1998 and 2017 were included. Fourteen patients received grafts from matched sibling donors, 21 from suitable unrelated donors, and 32 from haploidentical family donors. Ex vivo CD3⁺ or αβ⁺ T cell-depleted grafts were used for haploidentical transplantation. Sixty-five patients (97.0%) achieved neutrophil engraftment at a median of 11 days. Haploidentical transplantation resulted in significantly faster neutrophil engraftment at a median of 10 days, compared with 14 days in cases of matched sibling donors and 12 days in cases of unrelated donor recipients. Nine patients experienced graft failure, and 5 of 7 who underwent a second transplantation are alive. There was no difference in the incidence of acute or chronic graft-versus-host disease based on donor type. The 5-year overall survival and failure-free survival rates were 93.8% ± 3.0% and 83.3% ± 4.6%, respectively, and there was no significant survival difference based on donor type. The survival outcomes of haploidentical transplantation in patients were comparable with those of matched sibling or unrelated donor transplantation. Optimized haploidentical transplantation using selective T cell depletion and conditioning regimens including low-dose total body irradiation for enhancing engraftment may be a realistic therapeutic option for pediatric patients with severe aplastic anemia.

The prognostic impact of lymphocyte subsets in newly diagnosed acute myeloid leukemia

Background

Tumor-infiltrating lymphocytes, which form a part of the host immune system, affect the development and progression of cancer. This study investigated whether subsets of lymphocytes reflecting host-tumor immunologic interactions are related to the prognosis of patients with acute myeloid leukemia (AML).

Methods

Lymphocyte subsets in the peripheral blood of 88 patients who were newly diagnosed with AML were analyzed by quantitative flow cytometry. The relationships of lymphocyte subsets with AML subtypes, genetic risk, and clinical courses were analyzed.

Results

The percentages of T and NK cells differed between patients with acute promyelocytic leukemia (APL) and those with AML with myelodysplasia-related changes. In non-APL, a high proportion of NK cells (>16.6%) was associated with a higher rate of death before remission (P=0.0438), whereas a low proportion of NK cells (≤9.4%) was associated with higher rates of adverse genetic abnormalities (P=0.0244) and relapse (P=0.0567). A multivariate analysis showed that the lymphocyte subsets were not independent predictors of survival.

Conclusion

Lymphocyte subsets at diagnosis differ between patients with different specific subtypes of AML. A low proportion of NK cells is associated with adverse genetic abnormalities, whereas a high proportion is related to death before remission. However, the proportion of NK cells may not show independent correlations with survival.

Cytokine secretion responsiveness of lymphomonocytes following cortisol cell exposure: Sex differences

The stress hormone cortisol has been recognized as a coordinator of immune response. However, its different ability to modulate the release of inflammatory mediators in males and females has not been clarified yet. Indeed, the dissection of cortisol specific actions may be difficult due to the complex hormonal and physio-pathological individual status. Herein, the release of inflammatory mediators following increasing cortisol concentrations was investigated in an in vitro model of primary human male and female lymphomonocytes. The use of a defined cellular model to assess sex differences in inflammatory cytokine secretion could be useful to exclude the effects of divergent and fluctuating sex hormone levels occurring in vivo. Herein, the cells were challenged with cortisol concentrations resembling the plasma levels achieving in physiological and stressful conditions. The production of cytokines and other molecules involved in inflammatory process was determined. In basal conditions, male cells presented higher levels of some pro-inflammatory molecules (NF-kB and IDO-1 mRNAs, IL-6 and kynurenine) than female cells. Following cortisol exposure, the levels of the pro-inflammatory cytokines, IL-6 and IL-8, were increased in male cells. Conversely, in female cells IL-6 release was unchanged and IL-8 levels were decreased. Anti-inflammatory cytokines, IL-4 and IL-10, did not change in male cells and increased in female cells. Interestingly, kynurenine levels were higher in female cells than in male cells following cortisol stimulus. These results highlighted that cortisol differently affects male and female lymphomonocytes, shifting the cytokine release in favour of a pro-inflammatory pattern in male cells and an anti-inflammatory secretion profile in female cells, opening the way to study the influences of other stressful factors involved in the neurohumoral changes occurring in the response to stress conditions.

Altered immune responses in broiler chicken husbandry workers and their association with endotoxin exposure

Exposure to bioaerosols in indoor animal farms associates with respiratory illnesses, but little is known about the immune modulation to chicken farmers. This study aimed to compare the general immunity of chicken farmers with those of control subjects with non-agricultural jobs. Blood taken from the farmers and controls was subjected to plasma IgE and IgG subclass measurements. Isolated peripheral blood mononuclear cells (PBMC) were stimulated and cytokine production was measured. Indoor total and respirable dust levels and their endotoxin (LPS) and aflatoxin (AF) levels in the farms were measured. In total, 29 chicken farmers on 19 farms and 14 age- and sex-matched office workers participated. Hematological differences were not observed. The farmers tended to have higher serum IgE and IgG subclass levels with significance for IgG1. The cytokines released by PBMC from farmers indicated skewing toward Type-2 helper T-cell responses: interferon (IFN)-γ:interleukin (IL)-4 and IFNγ:IL-13 ratios were significantly lower than for control PBMC. The farms had 707.1 EU/m3 LPS in total dust, and 15.8 EU/m3 LPS in respirable dust. Farmers exhibited immune skewing towards allergic immune responses that correlated with the LPS levels on their farms. Chicken farmers may be at risk of respiratory allergies due to occupational endotoxin exposure.

Hemacytotoxicity and natural killer lytic index: New parameters to evaluate natural killer cell immunity for clinical use in cancer

Cytotoxicity assays with patient peripheral blood mononuclear cell (PBMC)-derived natural killer (NK) cells are useful in evaluating the innate immunity of patients with cancer. However, the size of the NK cell population in PBMC preparations may have significant effects on the assay outcome. Therefore, the present study examined the effect of NK cell frequency in a cytotoxicity system to investigate NK cell immunity in post-surgical colorectal cancer patients. For this, hemacytotoxicity was assessed using PBMC preparations, and lymphocyte subset populations were analyzed in samples obtained from 47 patients and 45 healthy volunteers. In addition, a new theoretical parameter, the 'NK lytic index', was termed to represent the per-cell cytotoxicity and compensate for the NK cell frequency effect during PBMC preparations. Notably, the patterns of hemacytotoxicity and NK lytic index did not coincide in follow-up studies with consecutive patients following surgical intervention. In addition, it was determined that NK cell NKG2D expression influences NK lytic index, but not hemacytotoxicity. Transforming growth factor (TGF)-β-bound lymphocytes influenced hemacytotoxicity and NK lytic index. These findings indicate that total cell activity (hemacytotoxicity) is not a sum of per-cell activities (NK lytic indexes), suggesting that clinicians should employ NK lytic index in addition to hemacytotoxicity in order to precisely determine how to enhance NK cell immunity in patients with cancer, either focusing on recovering the number of NK cells or boosting NK cell activity in single cell levels, or both.

Reference Values for a Panel of Cytokinergic and Regulatory Lymphocyte Subpopulations

Lymphocyte subpopulations producing cytokines and exerting regulatory functions represent key immune elements. Given their reciprocal interdependency lymphocyte subpopulations are usually assayed as diagnostic panels, rather than single biomarkers for specialist clinical use. This retrospective analysis on lymphocyte subpopulations, analyzed over the last few years in an outpatient laboratory in Northeast Italy, contributes to the establishment of reference values for several regulatory lymphocytes currently lacking such reference ranges for the general population. Mean values and ranges in a sample of Caucasian patients (mean age 42±8,5 years), were provided for Th1, Th2, Th17, Th-reg, Tc-reg, Tc-CD57⁺ and B1 lymphocytes. The results are consistent with what is found in literature for the single subtypes and are: Th1 157.8±60.3/µl (7.3%±2.9); Th2 118.2±52.2/µl (5.4%±2.5); Th17 221.6±90.2/µl (10.5%±4.4); Th-reg 15.1±10.2/µl (0.7%±0.4); Tc-reg 5.8±4.7/µl (0.3%±0.2); Tc-CD57+ 103.7±114.1/µl (4.6%±4.7); B1 33.7±22.8/µl (1.5%±0.9); (Values are mean±SD). The results show that despite their variability, mean values are rather consistent in all age or sex groups and can be used as laboratory internal reference for this regulatory panel. Adding regulatory cells to lymphocyte subpopulations panels allows a more complete view of the state of the subject's immune network balance, thus improving the personalization and the "actionability" of diagnostic data in a systems medicine perspective.

Natural killer cell subsets and receptor expression in peripheral blood mononuclear cells of a healthy Korean population: Reference range, influence of age and sex, and correlation between NK cell receptors and cytotoxicity

BACKGROUND

The purpose of this study was to identify CD56^bright and CD56^dim natural killer (NK) cell subsets and analyze their receptors expression in a healthy Korean population, and to determine whether receptor expression correlates with age, sex, and cytotoxicity.

MATERIALS AND METHODS

We performed multicolor flow cytometry assays to analyze the expression of various NK cell receptors (CD16, NKG2A, NKG2C, NKG2D, CD57, DNAM-1, CD8a, CD62L, NKp30, and NKp46) on both CD3^-/CD56^dim and CD3^-/CD56^bright NK cells in whole-blood samples from 122 healthy donors. The expression of these receptors was compared according to age (<30years, n=22, 30-60years, n=73 and >60years, n=27) and gender (male, n=61, female, n=61). NK cell cytotoxicity assays were performed with peripheral blood mononuclear cells (PBMCs) from 18 individuals. The results were compared to the expression levels of NKp30 and NKp46 receptors.

RESULTS

A normal reference range for NK cell receptor expression in two NK cell subsets was established. NKp46 and NKG2D expression gradually decreased with age (p<0.01 and p<0.05, respectively) whereas NK cell proportion and numbers, frequencies of CD56^dim cells, and CD57 expression increased with age (p<0.01 in all cases). Men showed greater NK cell proportion and numbers, frequencies of CD56^dim cells, and CD57 expression compared to those of women (p<0.05 and p<0.001; p<0.01 and p<0.01, respectively). Notably, the expression of NKp46 was negatively correlated with NK cell frequency (r=-0.42, p<0.001). Furthermore, NK cell cytotoxicity was found to positively correlate with NCR expression (p=0.02), but not NK cell proportion (p=0.80).

CONCLUSION

We have established a profile of NK cell surface receptors for a Korean population, and revealed that age and gender have an effect on the expression of NK cell receptors in the population. Our data might explain why neither NK cell numbers nor proportions correlate with NK cell cytotoxicity.

The "killer cell story" in recurrent miscarriage: Association between activated peripheral lymphocytes and uterine natural killer cells

Peripheral and uterine NK cells (pNK, uNK) can be distinguished according to their receptor expression. Recent studies indicate an association of elevated pNK and uNK with recurrent miscarriage (RM). This study aimed to analyze pNK and uNK in patients with RM and healthy controls. Out of n=590 RM patients screened according to a standard diagnostic protocol, n=268 couples with ≥3 consecutive RM were identified. Subgroups consisted of n=151 primary RM (pRM), n=85 secondary RM (sRM), n=32 tertiary RM (tRM) and n=42 healthy controls. Finally, n=147 idiopathic RM (iRM) and n=121 non-iRM patients were identified. Peripheral blood levels of CD45+CD3-CD56+CD16+ NK cells were determined in non-pregnant patients and controls in the mid-luteal phase by FACS. In n=129 RM patients a uterine biopsy was taken to evaluate CD56+ NK cells by immunohistochemistry. PRM showed higher absolute pNK than sRM (median/μl (Q1;Q3): 234 (147;306) vs 176 (128;245), p=0.02). Further a trend towards higher pNK percentages in pRM was detected. UNK numbers did not differ between RM subgroups and did not correlate with pNK. However, the rate of highly elevated uNK was increased in iRM compared to non-iRM patients (p=0.04). Further, higher numbers of CD45+CD3-DR+ (p<0.01) and CD45+CD3+CD8+DR+ (p=0.04) peripheral lymphocytes were associated with higher uNK numbers. In conclusion, elevated pNK were present in pRM patients. Although pNK and uNK numbers did not correlate, the association between high CD45+CD3-DR+ and CD45+CD3+CD8+DR+ peripheral lymphocytes and uNK might indicate that activated NK, B and T cells provide cytokines for the differentiation of uNK.