DNA methylation and gene expression of immune cell markers in adolescents with chronic cannabis use: an exploratory study

BACKGROUND

Experimental studies indicate that phytocannabinoids have immune-modulatory properties. However, the effects of chronic cannabis use (CCU) in adolescents on their immune cells have been scarcely investigated to date, although CCU is increasingly observed in this age group.

METHODS

In this study, we analyzed DNA methylation and gene expression of immune cell markers in whole-blood samples of adolescent CCU-outpatients and non-cannabis-using (NCU) controls (n = 14 vs. n = 15, mean age = 16.1 ± 1.3 years). Site-specific DNA methylation values were used to calculate A) proportion estimates of circulating white blood cell (WBC) types and B) mean DNA methylation values of common immune cell markers (CD4, CD8A, CD19, FCGR3A, CD14, FUT4, MPO), whose gene expression levels were additionally determined.

RESULTS

CCU adolescents had a lower estimated proportion of B cells compared to NCU subjects. An originally observed higher proportion of granulocytes in CCU subjects, however, was attenuated when controlling for past-year tobacco use. The observed differences in mean DNA methylation and gene expression of immune cell markers were not statistically significant.

CONCLUSION

The results of our explorative study indicate that CCU in adolescents is associated with altered levels of circulating WBCs. Further studies with larger cohorts are warranted to confirm our findings and to provide insights regarding their functional consequences.

Smoking and osteoimmunology: Understanding the interplay between bone metabolism and immune homeostasis

Smoking continues to pose a global threat to morbidity and mortality in populations. The detrimental impact of smoking on health and disease includes bone destruction and immune disruption in various diseases. Osteoimmunology, which explores the communication between bone metabolism and immune homeostasis, aims to reveal the interaction between the osteoimmune systems in disease development. Smoking impairs the differentiation of mesenchymal stem cells and osteoblasts in bone formation while promoting osteoclast differentiation in bone resorption. Furthermore, smoking stimulates the Th17 response to increase inflammatory and osteoclastogenic cytokines that promote the receptor activator of NF-κB ligand (RANKL) signaling in osteoclasts, thus exacerbating bone destruction in periodontitis and rheumatoid arthritis. The pro-inflammatory role of smoking is also evident in delayed bone fracture healing and osteoarthritis development. The osteoimmunological therapies are promising in treating periodontitis and rheumatoid arthritis, but further research is still required to block the smoking-induced aggravation in these diseases.

Translational potential

This review summarizes the adverse effect of smoking on mesenchymal stem cells, osteoblasts, and osteoclasts and elucidates the smoking-induced exacerbation of periodontitis, rheumatoid arthritis, bone fracture healing, and osteoarthritis from an osteoimmune perspective. We also propose the therapeutic potential of osteoimmunological therapies for bone destruction aggravated by smoking.

Fine particulate matter aggravates smoking induced lung injury via NLRP3/caspase-1 pathway in COPD

BACKGROUND

Exposure to noxious particles, including cigarette smoke and fine particulate matter (PM2.5), is a risk factor for chronic obstructive pulmonary disease (COPD) and promotes inflammation and cell death in the lungs. We investigated the combined effects of cigarette smoking and PM2.5 exposure in patients with COPD, mice, and human bronchial epithelial cells.

METHODS

The relationship between PM2.5 exposure and clinical parameters was investigated in patients with COPD based on smoking status. Alveolar destruction, inflammatory cell infiltration, and pro-inflammatory cytokines were monitored in the smoking-exposed emphysema mouse model. To investigate the mechanisms, cell viability and death and pyroptosis-related changes in BEAS-2B cells were assessed following the exposure to cigarette smoke extract (CSE) and PM2.5.

RESULTS

High levels of ambient PM2.5 were more strongly associated with high Saint George's respiratory questionnaire specific for COPD (SGRQ-C) scores in currently smoking patients with COPD. Combined exposure to cigarette smoke and PM2.5 increased mean linear intercept and TUNEL-positive cells in lung tissue, which was associated with increased inflammatory cell infiltration and inflammatory cytokine release in mice. Exposure to a combination of CSE and PM2.5 reduced cell viability and upregulated NLRP3, caspase-1, IL-1β, and IL-18 transcription in BEAS-2B cells. NLRP3 silencing with siRNA reduced pyroptosis and restored cell viability.

CONCLUSIONS

PM2.5 aggravates smoking-induced airway inflammation and cell death via pyroptosis. Clinically, PM2.5 deteriorates quality of life and may worsen prognosis in currently smoking patients with COPD.

Association of immune cell composition with the risk factors and incidence of acute coronary syndrome

BACKGROUND

Although immune cells are involved in acute coronary syndrome (ACS), few studies have explored the association of incident ACS with the relative immune cell proportions. We aimed to investigate the association of immune cell proportions with the incidence and risk factors of ACS in the Dongfeng-Tongji cohort.

METHODS

We conducted the analyses with 38,295 subjects from the first follow-up of the Dongfeng-Tongji cohort, including DNA methylation profiles for 1570 individuals. The proportions of immune cell types were observed from routine blood tests or estimated from DNA methylation profiles. For both observed and estimated immune cell proportions, we tested their associations with risk factors of ACS by multivariable linear regression models. In addition, the association of each immune cell proportion with incident ACS was assessed by the Cox regression model and conditional logistic regression model, respectively, adjusting for the risk factors of ACS.

FINDINGS

The proportions of lymphocytes, monocytes, and neutrophils showed strong associations with sex, followed by diabetes. Moreover, sex and current smoking were the two factors with strongest association with the proportions of lymphocyte subtypes. The hazard ratio (HR) and 95% confidence interval (CI) of incident ACS per standard deviation (SD) increase in proportions of lymphocytes and neutrophils were 0.91 (0.85-0.96) and 1.10 (1.03-1.16), respectively. Furthermore, the OR (95% CI) of incident ACS per SD increase in proportions of NK cells, CD4⁺ T cells, and B cells were 0.88 (0.78-0.99), 1.15 (1.03-1.30), and 1.13 (1.00-1.26), respectively.

INTERPRETATION

The proportions of immune cells were associated with several risk factors of ACS, including sex, diabetes, and current smoking. In addition, proportion of neutrophils had a risk effect, while proportion of lymphocytes had a protective effect on the incidence of ACS. The protective effect of lymphocytes was probably driven by NK cells.

Cigarette smoking is associated with an increase in blood monocytes in people with tuberculosis: A cross-sectional study

The effect of smoking on immune responses in people with tuberculosis (TB) is not well elucidated. We aimed to compare peripheral blood counts of CD4+ and CD87 + T-lymphocytes, monocytes, and neutrophils and the CD4:CD8 ratio in TB patients with and without history of cigarette smoking. We further determined factors associated with current smoking. Participants with TB were consecutively enrolled in a cross-sectional study at a national TB treatment center in Uganda in 2018. We compared cell counts and the CD4:CD8 ratio using the median test among never smokers, past smokers (>6 months ago) and current smokers (≤6 months). Factors associated with current smoking were determined using logistic regression. A post hoc analysis for factors associated with an increase in the monocytes was also performed. Of 363 participants, there were 258 (71.1%) never smokers, 50 (13.8%) past smokers, and 55 (15.2%) current smokers. Most current smokers (49.1%) had a high sputum mycobacterial load. They also had the lowest body mass index and the highest axillary temperature. The median (interquartile range [IQR]) monocyte count among current smokers was 815 (540-1425) cells/mm3 and was significantly higher than that among past smokers (610 (350-900) cells/mm3, P = .017) and never smokers (560 [400-800] cells/mm3, P = .001). The monocyte counts positively correlated with the number of cigarettes smoked per day among current smokers (R = 0.43, P = .006). Current smokers also had higher neutrophil and CD4+ T-cell counts than never smokers. In a multivariable logistic regression model, an increase in the monocyte count was associated with current cigarette smoking (adjusted odds ratio [aOR] = 4.82, 95% confidence interval 1.61-14.39, P = .005). Similarly, current cigarette smoking was independently associated with an increase in the monocyte count (aOR = 1.80, 95% CI 1.39-2.32, P < .001). Cigarette smoking is associated with an increase in the blood monocytes in people with TB in a dose- and time-dependent manner. Further, current smoking is associated with an increase in neutrophils and CD4+ T-lymphocytes. The findings suggest that current smokers have systemic inflammation that is not necessarily beneficial to TB control in TB patients.

On the toxicity of e-cigarettes consumption: Focus on pathological cellular mechanisms

Tobacco smoking remains without a doubt one of the leading causes of premature death worldwide. In combination with conventional protocols for smoking cessation, e-cigarettes have been proposed as a useful tool to quit smoking. Advertised as almost free of toxic effects, e-cigarettes have rapidly increased their popularity, becoming a sought-after device, especially among young people. Recently some health concerns about e-cigarette consumption are being raised. It is well known that they can release several toxic compounds, some of which are carcinogenic to humans, and emerging results are now outlining the risks related to the onset of respiratory and cardiovascular diseases and even cancer. The present review shows the emerging evidence about the role of technical components of the devices, the e-liquid composition as well as customization by consumers. The primary topics we discuss are the main toxicological aspects associated with e-cigarette consumption, focusing on the molecular pathways involved. Here it will be shown how exposure to e-cigarette aerosol induces stress/mitochondrial toxicity, DNA breaks/fragmentation following the same pathological pathways triggered by tobacco smoke, including the deregulation of molecular signalling axis associated with cancer progression and cell migration. Risk to fertility and pregnancy, as well as cardiovascular risk associated with e-cigarette use, have also been reported.

Lymphoma-Associated Biomarkers Are Increased in Current Smokers in Twin Pairs Discordant for Smoking

Simple Summary

Smoking is associated with a moderate increased risk of Hodgkin and follicular lymphoma. To help understand why, we examined lymphoma-related biomarker levels among 134 smoking and non-smoking twins (67 pairs) ascertained from the Finnish Twin Cohort. We validated self-reported smoking history by measuring serum cotinine, a metabolite of nicotine, from previously collected frozen serum samples. In total, 27 immune biomarkers were assayed using the Luminex Multiplex platform (R & D Systems). We found that four immune response biomarkers were higher and one was lower among smoking compared to non-smoking twins. The strongest association was observed for CCL17/TARC, a biomarker elevated in Hodgkin lymphoma patients. Immune biomarker levels were similar in former smokers and non-smokers. Current smoking may increase levels of immune proteins that could partially explain the association between smoking and risk of certain lymphomas.

Abstract

Smoking is associated with a moderate increased risk of Hodgkin and follicular lymphoma. To understand why, we examined lymphoma-related biomarker levels among 134 smoking and non-smoking twins (67 pairs) ascertained from the Finnish Twin Cohort. Previously collected frozen serum samples were tested for cotinine to validate self-reported smoking history. In total, 27 immune biomarkers were assayed using the Luminex Multiplex platform (R & D Systems). Current and non-current smokers were defined by a serum cotinine concentration of >3.08 ng/mL and ≤3.08 ng/mL, respectively. Associations between biomarkers and smoking were assessed using linear mixed models to estimate beta coefficients and standard errors, adjusting for age, sex and twin pair as a random effect. There were 55 never smokers, 43 current smokers and 36 former smokers. CCL17/TARC, sgp130, haptoglobin, B-cell activating factor (BAFF) and monocyte chemoattractant protein-1 (MCP1) were significantly (p < 0.05) associated with current smoking and correlated with increasing cotinine concentrations (P_trend < 0.05). The strongest association was observed for CCL17/TARC (P_trend = 0.0001). Immune biomarker levels were similar in former and never smokers. Current smoking is associated with increased levels of lymphoma-associated biomarkers, suggesting a possible mechanism for the link between smoking and risk of these two B-cell lymphomas.

Immunological Status of Bladder Cancer Patients Based on Urine Leukocyte Composition at Radical Cystectomy

Background: Bladder cancer (BC) is the ninth most common malignancy worldwide, with high rates of recurrence. The use of urine leukocyte composition at the time of radical cystectomy (RC) as a marker for the study of patients’ immunological status and to predict the recurrence of muscle-invasive bladder cancer (MIBC) has received little attention. Methods: Urine and matched peripheral blood samples were collected from 24 MIBC patients at the time of RC. Leukocyte composition and expression of PD-L1 and PD-1 in each subpopulation were determined by flow cytometry. Results: All MIBC patients had leukocytes in urine. There were different proportions of leukocyte subpopulations. The expression of PD-L1 and PD-1 on each subpopulation differed between patients. Neoadjuvant chemotherapy (NAC), smoking status, and the affectation of lymph nodes influenced urine composition. We observed a link between leukocytes in urine and blood circulation. Recurrent patients without NAC and with no affectation of lymph nodes had a higher proportion of lymphocytes, macrophages, and PD-L1+ neutrophils in urine than non-recurrent patients. Conclusions: Urine leukocyte composition may be a useful tool for analyzing the immunological status of MIBC patients. Urine cellular composition allowed us to identify a new subgroup of LN− patients with a higher risk of recurrence.

Systemic circulating inflammatory burden and periodontitis in adolescents

OBJECTIVES

To analyze the association between systemic inflammatory burden of cardiovascular disease (CVD) risk and periodontitis in adolescents, including mediating pathways triggered by their common risk factors.

MATERIALS AND METHODS

Using a population-based sample study (n = 405) of Brazilian adolescents (17-18 years old), direct and mediation pathways triggered by "Socioeconomic Status," "Adiposity," Smoking, and "Blood Pressure" were modelled for the association between the "Systemic Circulating Inflammatory Burden of CVD Risk" (IL-1β, IL-6, IL-8, TNF-α) and the "Initial Periodontitis" (bleeding on probing (BoP), probing depth (PD) ≥ 4 mm, clinical attachment loss (CAL) ≥ 4 mm), both as continuous latent variables, using structural equation modeling. Sensitivity analysis was performed for the outcomes "Gingivitis" (visible plaque; BoP); "Moderate Periodontitis" (PD ≥ 5 mm and CAL ≥ 5 mm) and periodontitis (CDC-AAP case definition).

RESULTS

Higher "Systemic Circulating Inflammatory Burden of CVD Risk" was directly associated with higher "Initial Periodontitis" (standardized coefficient [SC] = 0.178, P value < 0.001). Lower "Socioeconomic Status" (SC = - 0.022, P value = 0.015) and Smoking (SC = 0.030, P value = 0.021) triggered the "Initial Periodontitis", mediated by "Systemic Circulating Inflammatory Burden of CVD Risk". Sensitivity analysis showed a dose-response relationship between "Systemic Circulating Inflammatory Burden of CVD Risk" and "Moderate Periodontitis" (SC = 0.323, P value = 0.021).

CONCLUSIONS

"Systemic Circulating Inflammatory Burden of CVD Risk" appeared as an underlying mechanism of early periodontal breakdown in adolescents, also triggered by social vulnerability and smoking.

CLINICAL RELEVANCE

The association between periodontitis and CVD in adulthood seems to establish much earlier in life than had been previously studied, giving impetus to preventive approaches focused on their common risk factors.

Patterns of Antiretroviral Therapy Use and Immunologic Profiles at Enrollment in the REPRIEVE Trial

BACKGROUND

Patterns of antiretroviral therapy (ART) use and immunologic correlates vary globally, and contemporary trends are not well described.

METHODS

The REPRIEVE trial (Randomized Trial to Prevent Vascular Events in HIV) enrolled persons with human immunodeficiency virus (HIV) who were aged 40-75 years, receiving ART, and had low-to-moderate cardiovascular disease risk. ART use was summarized within Global Burden of Disease (GBD) super-regions, with adjusted linear and logistic regression analyses examining associations with immune parameters and key demographics.

RESULTS

A total of 7770 participants were enrolled, with a median age of 50 years (interquartile range, 45-55 years); 31% were female, 43% were black or African American, 15% were Asian, 56% had a body mass index >25 (calculated as weight in kilograms divided by height in meters squared), and 49% were current or former smokers. The median CD4 T-cell count was 620/µL (interquartile range, 447-826/ µ L), and the median duration of prior ART use, 9.5 years (5.3-14.8) years. The most common ART regimens were nucleoside/nucleotide reverse-transcriptase inhibitor (NRTI) plus nonnucleoside reverse-transcriptase inhibitor (43%), NRTI plus integrase strand transfer inhibitor (25%), and NRTI plus protease inhibitor (19%). Entry ART varied by GBD region, with shifts during the trial enrollment period. In adjusted analyses, entry CD4 cell count and CD4/CD8 ratio were associated with GBD region, sex, entry regimen, duration of ART, and nadir CD4 cell count; CD4 and CD8 cell counts were also associated with body mass index and smoking status.

CONCLUSIONS

There were substantial variations in ART use by geographic region and over time, likely reflecting the local availability of specific medications, changes in treatment guidelines and provider/patient preferences. The analyses of CD4 cell counts and CD4/CD8 ratios may provide valuable insights regarding immune correlates and outcomes in people living with HIV.

CLINICAL TRIALS REGISTRATION

NCT02344290.

Immune Trait Shifts in Association With Tobacco Smoking: A Study in Healthy Women

Tobacco smoking is known to impact circulating levels of major immune cells populations, but its effect on specific immune cell subsets remains poorly understood. Here, using high-resolution data from 223 healthy women (25 current and 198 never smokers), we investigated the association between smoking status and 35,651 immune traits capturing immune cell subset frequencies. Our results confirmed that active tobacco smoking is associated with increased frequencies of circulating CD8+ T cells expressing the CD25 activation marker. Moreover, we identified novel associations between smoking status and relative abundances of CD8+ CD25+ memory T cells, CD8+ memory T cells expressing the CCR4 chemokine receptor, and CD4+CD8+ (double-positive) CD25+ T cells. We also observed, in current smokers, a decrease in the relative frequencies of CD4+ T cells expressing the CD38 activation marker and an increase in class-switched memory B cell isotypes IgA, IgG, and IgE. Finally, using data from 135 former female smokers, we showed that the relative frequencies of immune traits associated with active smoking are usually completely restored after smoking cessation, with the exception of subsets of CD8+ and CD8+ memory T cells, which persist partially altered. Our results are consistent with previous findings and provide further evidence on how tobacco smoking shapes leukocyte cell subsets proportion toward chronic inflammation.

Nicotine promotes breast cancer metastasis by stimulating N2 neutrophils and generating pre-metastatic niche in lung

Smoking has a profound impact on tumor immunity, and nicotine, which is the major addictive component of smoke, is known to promote tumor progression despite being a non-carcinogen. In this study, we demonstrate that chronic exposure of nicotine plays a critical role in the formation of pre-metastatic niche within the lungs by recruiting pro-tumor N2-neutrophils. This pre-metastatic niche promotes the release of STAT3-activated lipocalin 2 (LCN2), a secretory glycoprotein from the N2-neutrophils, and induces mesenchymal-epithelial transition of tumor cells thereby facilitating colonization and metastatic outgrowth. Elevated levels of serum and urine LCN2 is elevated in early-stage breast cancer patients and cancer-free females with smoking history, suggesting that LCN2 serve as a promising prognostic biomarker for predicting increased risk of metastatic disease in female smoker(s). Moreover, natural compound, salidroside effectively abrogates nicotine-induced neutrophil polarization and consequently reduced lung metastasis of hormone receptor-negative breast cancer cells. Our findings suggest a pro-metastatic role of nicotine-induced N2-neutrophils for cancer cell colonization in the lungs and illuminate the therapeutic use of salidroside to enhance the anti-tumor activity of neutrophils in breast cancer patients.

Smoking is known to impact tumor immunity and promote tumor progression. Here, the authors show that chronic nicotine exposure promotes the lung pre-metastatic niche formation by recruiting pro-tumor N2-neutrophils that release lipocalin-2.

The Customizable E-cigarette Resistance Influences Toxicological Outcomes: Lung Degeneration, Inflammation, and Oxidative Stress-Induced in a Rat Model

Despite the knowledge gap regarding the risk-benefit ratio of the electronic cigarette (e-cig), its use has grown exponentially, even in teenagers. E-cig vapor contains carcinogenic compounds (eg, formaldehyde, acetaldehyde, and acrolein) and free radicals, especially reactive oxygen species (ROS) that cause toxicological effects, including DNA damage. The role of e-cig voltage customization on molecule generation has been reported, but the effects of the resistance on e-cig emissions and toxicity are unknown. Here, we show that the manipulation of e-cig resistance influences the carbonyls production from nonnicotine vapor and the oxidative and inflammatory status in a rat model. Fixing the voltage at the conventional 3.5 V, we observed that the amount of the selected aldehydes increased as the resistance decreased from 1.5 to 0.25 Ω. Under these conditions, we exposed Sprague Dawley rats to e-cig aerosol for 28 days, and we studied the pulmonary inflammation, oxidative stress, tissue damage, and blood homeostasis. We found a perturbation of the antioxidant and phase II enzymes, probably related to the increased ROS levels due to the enhanced xanthine oxidase and P450-linked monooxygenases. Furthermore, frames from scanning electron microscope showed a disorganization of alveolar and bronchial epithelium in 0.25 Ω group. Overall, various toxicological outcomes, widely recognized as smoke-related injuries, can potentially occur in e-cig consumers who use low-voltage and resistance device. Our study suggests that certain “tips for vaping safety” cannot be established, and encourages further independent investigations to help public health agencies in regulating the e-cig use.

New inflammatory indicators: association of high eosinophil-to-lymphocyte ratio and low lymphocyte-to-monocyte ratio with smoking

Objective

Smoking has been proven to increase systemic inflammation in previous studies using different biomarkers. The eosinophil-to-lymphocyte ratio (ELR), neutrophil-to-lymphocyte ratio (NLR), and lymphocyte-to-monocyte ratio (LMR) are new indicators of systemic inflammation that are used as predictors of systemic inflammation, morbidity, and mortality associated with many diseases. We investigated the effects of smoking on these inflammatory indicators.

Methods

In total, 616 consecutive smoking healthy subjects and 387 age-matched nonsmoking healthy subjects were enrolled. White blood cell counts (neutrophils, lymphocytes, basophils, eosinophils, and monocytes) were determined by electrical impedance with an automatic blood cell counting device. The ELR, LMR, and NLR were calculated based on these cell counts. Smoking habits of participants were calculated as pack/year.

Results

The NLR and ELR were significantly higher and the LMR was significantly lower in smokers than nonsmokers. The pack-years were positively correlated with the NLR and ELR and negatively correlated with the LMR.

Conclusion

A high NLR and ELR and low LMR are associated with cigarette smoking and may be useful indicators of systemic inflammation activity, even in healthy smokers. Smokers with a high NLR and ELR and low LMR can easily be identified during routine blood analysis and might benefit from preventive treatment.

Role of natural killer cells in lung cancer

PURPOSE

One of the key immune cells involved in the pathogenesis of lung cancer is natural killer (NK) cells and these cells are novel targets for therapeutic applications in lung cancer. The purpose of this review is to summarize the current literature on lung cancer pathogenesis with a focus on the interaction between NK cells and smoking, how these factors are related to the pathogenesis of lung cancer and how NK cell-based immunotherapy effect lung cancer survival.

METHODS

The relevant literature from PubMed and Medline databases is reviewed in this article.

RESULTS

The cytolytic potential of NK cells are reduced in lung cancer and increasing evidence suggests that improving NK cell functioning may induce tumor regression. Recent clinical trials on NK cell-based novel therapies such as cytokines including interleukin (IL)-15, IL-12 and IL-2, NK-92 cell lines and allogenic NK cell immunotherapy showed promising results with less adverse effects on the lung cancer survival.

CONCLUSIONS

The NK cell targeting strategy has not yet been approved for lung cancer treatment. More clinical studies focusing on the role of NK cells in lung cancer pathogenesis are warranted to develop novel NK cell-based therapeutic approaches for the treatment of lung cancer.

Interaction among smoking status, single nucleotide polymorphisms and markers of systemic inflammation in healthy individuals

Cigarette smoke contains toxic and carcinogenic substances that contribute to the development of cancer and various diseases. Genetic variation might be important, because not all smokers develop smoking-related disease. The current study addressed the possible interactions among selected single nucleotide polymorphisms (SNPs) in genes related to systemic inflammation, smoking status, the levels of circulating immune response cells and plasma biomarkers of systemic inflammation. Sixty-four healthy blood donors were recruited, 31 of whom were current smokers and 33 were never-users of tobacco products, references. Compared to references, the smokers showed significantly increased levels of circulating total white blood cells, lymphocytes, monocytes, neutrophils, basophils and C-reactive protein (CRP). Smokers also more frequently exhibited circulating cell phenotypes that are associated with an immunocompromised state: CD8^dim cells in the lymphocyte group, CD13⁺  CD11⁺ , CD13⁺  CD14⁺ , CD13⁺  CD56⁺ cells in the monocyte group and CD13⁺  CD11⁺ , CD13⁺  CD56⁺ cells in the neutrophil group. We observed an interaction among SNPs, smoking status and some of the studied biomarkers. The average plasma CRP level was significantly higher among the smokers, with the highest level found among those with the CRP rs1800947 CC genotype. Additionally, an increased CD8⁺  GZB⁺ cells in the CD8^dim group were found among smokers with the GZB rs8192917 AA genotype. Thus, smoking appears to be associated with systemic inflammation and increased levels of circulating immunosuppressive cells. The extent of these effects was associated with SNPs among the smokers. This observation may contribute to a better understanding of the genetic susceptibility of smoking-related disease and the variations observed in clinical outcomes.

Telomerase activity, telomere length and hTERT DNA methylation in peripheral blood mononuclear cells from monozygotic twins with discordant smoking habits

Increased telomerase expression has been implicated in the pathogenesis of lung cancer and, since the primary cause of lung cancer is smoking, an association between telomerase reactivation and tobacco smoke has been proposed. In this work an investigation has been performed to assess the relationship between tobacco smoke exposure and telomerase activity (TA) in peripheral blood mononuclear cells of healthy smokers. The methylation status of the catalytic subunit of telomerase hTERT was concurrently investigated to assess the possible association between epigenetic modifications of hTERT and TA. Besides, the association between smoke and telomere length (TL) has been evaluated. Healthy monozygotic twins with discordant smoking habits were selected as study population to minimize inter-individual differences because of demographic characteristics and genetic heterogeneity. Statistically significant higher values of TA and TL were observed in smokers compared to nonsmoker co-twins. The multivariate analysis of data showed, besides smoking habits (P = 0.02), an influence of gender (P = 0.006) and BMI (P = 0.001) on TA and a borderline effect of gender (P = 0.05) on TL. DNA methylation analysis, focused on 100 CpG sites mapping in hTERT, highlighted nine CpG sites differentially methylated in smokers. When co-twins were contrasted, selecting as variables the intra-twin difference in TA and hTERT DNA methylation, a statistically significant inverse correlation (P = 0.003) was observed between TA and DNA methylation at the cg05521538 site. In conclusion, these results indicate an association of tobacco smoke with TA and TL and suggest a possible association between smoke-induced epigenetic effects and TA in healthy smokers. Environ. Mol. Mutagen. 58:551-559, 2017. © 2017 Wiley Periodicals, Inc.

Causes of variation in the neutrophil-lymphocyte and platelet-lymphocyte ratios: a twin-family study

AIM

Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are biomarkers for disease development, for whom little is known about causes of variation in the general population.

MATERIALS & METHODS

We estimated the heritability of PLR and NLR and examined their association with gender, demographic, lifestyle and environmental factors in a Dutch nonpatient twin family population (n = 8108).

RESULTS

Heritability was estimated at 64% for PLR and 36% for NLR. Men had on average higher NLR, but lower PLR levels than women. PLR and NLR increased significantly with age, decreased in colder months and showed small but significant sex- and age-specific associations with body composition and smoking.

CONCLUSION

NLR and PLR levels are heritable and influenced by age, sex and environmental factors, such as seasonal conditions and lifestyle.

Prognostic value of pretreatment circulating neutrophils, monocytes, and lymphocytes on outcomes in lung stereotactic body radiotherapy

PURPOSE

In the present study, we determined the association of pretreatment circulating neutrophils, monocytes, and lymphocytes with clinical outcomes after lung stereotactic body radiotherapy (sbrt).

METHODS

All patients with primary lung cancer and with a complete blood count within 3 months of lung sbrt from 2005 to 2012 were included. Overall survival (os) was calculated using the Kaplan-Meier method. Factors associated with os were investigated using univariable and multivariable Cox proportional hazards regression. Fine-Gray competing risk regression was performed to test the association of the neutrophil:lymphocyte (nlr) and monocyte:lymphocyte (mlr) ratios with two types of failure: disease-related failure and death, and death unrelated to disease.

RESULTS

Of the 299 sbrt patients identified, 122 were eligible for analysis. The median and range of the nlr and mlr were 3.0 (0.3-22.0) and 0.4 (0.1-1.9) respectively. On multivariable analysis, sex (p = 0.02), T stage (p = 0.04), and nlr (p < 0.01) were associated with os. On multivariable analysis, T stage (p < 0.01) and mlr (p < 0.01) were associated with disease-related failure; mlr (p = 0.03), nlr (p < 0.01), and sbrt dose of 48 Gy in 4 fractions (p = 0.03) and 54 Gy or 60 Gy in 3 fractions (p = 0.02) were associated with disease-unrelated death. Median survival was 4.3 years in the nlr≤3 group (95% confidence interval: 3.5 to not reached) and 2.5 years in the nlr>3 group (95% confidence interval: 1.7 to 4.8; p < 0.01).

CONCLUSIONS

In lung sbrt patients, nlr and mlr are independently associated with os and disease-unrelated death. If validated, nlr and mlr could help to identify patients who would benefit most from sbrt.

Differential effects of Cytomegalovirus carriage on the immune phenotype of middle-aged males and females

The elderly population is more susceptible to infections as a result of an altered immune response, commonly referred to as immunosenescence. Cytomegalovirus (CMV)-infection associated changes in blood lymphocytes are known to impact this process, but the interaction with gender remains unclear. Therefore, we analysed the effects and interaction of gender and CMV on the absolute numbers of a comprehensive set of naive and memory T- and B-cell subsets in people between 50 and 65 years of age. Enumeration and characterisation of lymphocyte subsets by flow cytometry was performed on fresh whole blood samples from 255 middle-aged persons. CMV-IgG serostatus was determined by ELISA. Gender was a major factor affecting immune cell numbers. CMV infection was mainly associated with an expansion of late-differentiated T-cell subsets. CMV+ males carried lower numbers of total CD4+, CD4+ central memory (CM) and follicular helper T-cells than females and CMV- males. Moreover, CMV+ males had significantly lower numbers of regulatory T (Treg)-cells and memory B-cells than CMV+ females. We here demonstrate an interaction between the effects of CMV infection and gender on T- and B-cells in middle-aged individuals. These differential effects on adaptive immunity between males and females may have implications for vaccination strategies at middle-age.

Lymphocyte depletion and repopulation after chemotherapy for primary breast cancer

Background

Approximately 30 % of breast cancer patients receive chemotherapy, yet little is known about influences of current regimens on circulating lymphocyte levels and phenotypes. Similarly, clinico-pathological factors that modify these influences, and implications for future immune health remain mainly unexplored.

Methods

We used flow-cytometry to assess circulating lymphocyte levels and phenotypes in 88 primary breast cancer patients before chemotherapy and at time-points from 2 weeks to 9 months after chemotherapy completion. We examined circulating titres of antibodies against pneumococcal and tetanus antigens using ELISAs.

Results

Levels of B, T and NK cells were significantly reduced 2 weeks after chemotherapy (p < 0.001). B cells demonstrated particularly dramatic depletion, falling to 5.4 % of pre-chemotherapy levels. Levels of all cells recovered to some extent, although B and CD4⁺ T cells remained significantly depleted even 9 months post-chemotherapy (p < 0.001). Phenotypes of repopulating B and CD4⁺ T cells were significantly different from, and showed no sign of returning to pre-chemotherapy profiles. Repopulating B cells were highly depleted in memory cells, with proportions of memory cells falling from 38 % to 10 % (p < 0.001). Conversely, repopulating CD4⁺ T cells were enriched in memory cells, which increased from 63 % to 75 % (p < 0.001). Differences in chemotherapy regimen and patient smoking were associated with significant differences in depletion extent or repopulation dynamics. Titres of anti-pneumococcal and anti-tetanus antibodies were both significantly reduced post-chemotherapy and did not recover during the study (p < 0.001).

Conclusion

Breast cancer chemotherapy is associated with long-term changes in immune parameters that should be considered during clinical management.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-015-0669-x) contains supplementary material, which is available to authorized users.

Decreased Histone Deacetylase 2 (HDAC2) in Peripheral Blood Monocytes (PBMCs) of COPD Patients

BACKGROUND

Histone deacetylase 2 (HDAC2) is a class I histone deacetylase family member that plays a critical role in suppressing inflammatory gene expression in the airways, lung parenchyma, and alveolar macrophages in patients with chronic obstructive pulmonary disease (COPD). However, the expression of HDAC2 in peripheral blood monocytes (PBMCs), nuclear factor kappa B (NF-κB) p65, and serum inflammatory cytokine levels in COPD patients, smokers, and non-smokers remains unclear.

METHODS

PBMCs were obtained from COPD patients, healthy smokers, and healthy nonsmokers. The HDAC2 and NF-κB p65 expression were quantified by Western Blot. HDAC activity was assessed by an HDAC fluorometric immunoprecipitation activity assay kit. Serum tumor necrosis factor-alpha (TNF-α) and interleukin-8 (IL-8) levels were measured by ELISA.

RESULTS

HDAC2 expression and HDAC activity were decreased in PBMCs in COPD patients compared with smokers and non-smokers. Increased NF-κB p65 expression, serum TNF-α and IL-8 levels were observed in COPD patients compared with nonsmokers. The FEV1%pred was positively correlated with HDAC2 expression and HDAC activity in COPD patients. Smokers had decreased HDAC activity, increased NF-κB p65 expression and serum TNF-α compared with nonsmokers.

CONCLUSIONS

HDAC2 expression was decreased in PBMCs of COPD patients and was correlated with disease severity. The reduction of HDAC2 expression not only directly enhances the expression of inflammatory genes, but may account for the activation of NF-κB mediated inflammation. Decreased HDAC2 may serve as a potential biomarker of COPD and predict the decline of lung function.

Increased Neutrophil/Lymphocyte Ratio in Patients with Depression is Correlated with the Severity of Depression and Cardiovascular Risk Factors

OBJECTIVE

Chronic inflammation is associated with cardiovascular (CV) risk factors and psychiatric disorders. The neutrophil to lymphocyte ratio (NLR) has been investigated as a new biomarker for systemic inflammatory response. The aim of the study is to investigate the relation of NLR with severity of depression and CV risk factors.

METHODS

The study population consisted of 256 patients with depressive disorder. Patients were evaluated with the Hamilton Rating Scale for Depression (HAM-D). Patients were classified into four groups according to their HAM-D score such as mild, moderate, severe, and very severe depression. Patients were also evaluated in terms of CV risk factors.

RESULTS

Patients with higher HAM-D score had significantly higher NLR levels compared to patients with lower HAM-D score. Correlation analysis revealed that severity of depression was associated with NLR in depressive patients (r=0.333, p<0.001). Patients with one or more CV risk factors have significantly higher NLR levels. Correlation analysis revealed that CV risk factors were associated with NLR in depressive patients (r=0.132, p=0.034). In logistic regression analyses, NLR levels were an independent predictor of severe or very severe depression (odds ratio: 3.02, 95% confidence interval: 1.867-4.884, p<0.001). A NLR of 1.57 or higher predicted severe or very severe depression with a sensitivity of 61.4% and specificity of 61.2%.

CONCLUSION

Higher HAM-D scores are associated with higher NLR levels in depressive patients. NLR more than 1.57 was an independent predictor of severe or very severe depression. A simple, cheap white blood cell count may give an idea about the severity of depression.