Increase in memory (CD4+CD29+ and CD4+CD45RO+) T and naive (CD4+CD45RA+) T-cell subpopulations in smokers

Tobacco exposure, but not aging, shifts the frequency of peripheral blood B cell subpopulations

Several disturbances in T-cell mediated immunity have been described during aging, but immunosenescence of the B-cell compartment is less well elucidated. The peripheral blood B-cell compartment (CD19+) can be split into six main subpopulations according to the cell surface markers IgD, CD27, CD24, and CD38: Transitional, naïve, unswitched, switched, double negative and plasmablasts. We thus aimed to verify whether shifts in these subsets occur during healthy and pathological aging. We recruited three groups of aged people (> 60 years old), healthy, COPD patients, and smokers without altered pulmonary function test, and a fourth group of individuals 18-40 years old (youngs). Total B-cells percentage and absolute number were similar among the healthy aged, COPD patients, and youngs, but the smokers showed significantly higher absolute numbers. While all six B-cell subset percentages were comparable among the healthy aged, COPD patients, and youngs, smokers showed significantly higher percentages of switched B-cells and reduced naïve B-cells than the other three groups, resulting in an inverted naive:switched ratio. Analysis of the cell subset absolute numbers showed a similar trend. Overall, our results suggest that aging drives milder alterations in the distribution of peripheral blood B-cell subpopulations than in the T-cell compartment. We suggest that it is the T-cell immunosenescence that most contributes to the poor humoral immune responses in the elderly, vaccine responses included. Surprisingly it was the smokers who showed significant alterations when compared with the youngs, healthy aged, and aged COPD patients, probably as a result of the chronic immune stimulation described in active smoking subjects.

Clinical and Histopathological Factors Associated with the Tumoral Expression of TGF-β1, MED15, CD16, and CD57 in Oral Squamous Cell Carcinoma

Introduction

Factors associated with the expression of oral squamous cell carcinoma (OSCC) biomarkers “CD16, CD57, TGF-β1, and MED15” are not assessed, except in few controversial studies of some of these biomarkers. This study aimed to highlight factors that can correlate with tumoral overexpression of these biomarkers.

Methods

In this genetically-matched case-control study, biomarker expressions in all available OSCC tissues and their adjacent normal tissues at the National Tumor Center (n = 384 (4 biomarkers × (48 cancers + 48 controls))) were measured using qRT-PCR. Factors associated with tumoral overexpression of CD16, CD57, TGF-β1, and MED15 (compared to the benign control) were evaluated, using log-level multiple linear regressions and Spearman (α = 0.05).

Results

Tumoral CD16 upregulation was observed in younger patients (β = −0.284, P=0.040) and cigarette smokers (β = 0.397, P=0.005). Tumoral CD57 was upregulated in males (β = 0.341, P=0.008), smokers (β = 0.401, P=0.002), and cases without vascular invasion (β = −0.242, P=0.042). Tumoral TGF-β1 was elevated in smokers (β = 0.452, P=0.001) and smaller tumors (β = −0.322, P=0.045). Tumoral MED15 was overexpressed in smokers (β = 0.295, P=0.036) and cases lacking perineural invasion (β = −0.394, P=0.007).

Conclusion

As the most consistent finding, smoking might be positively associated with tumoral overexpression of all biomarkers. Tumoral increase in CD57 might be positively associated with metastasis while being negatively correlated with vascular and lymphatic invasion. Tumor size might be negatively associated with tumoral TGF-β1 expression.

Sex and gender differences in community-acquired pneumonia

Awareness of the influence of sex ands gender on the natural history of several diseases is increasing. Community-acquired pneumonia (CAP) is the most common acute respiratory disease, and it is associated with both morbidity and mortality across all age groups. Although a role for sex- and gender-based differences in the development and associated complications of CAP has been postulated, there is currently high uncertainty on the actual contribution of these factors in the epidemiology and clinical course of CAP. More evidence has been produced on the topic during the last decades, and sex- and gender-based differences have also been extensively studied in COVID-19 patients since the beginning of the SARS-CoV-2 pandemic. This review aims to provide an extensive outlook of the role of sex and gender in the epidemiology, pathogenesis, treatment, and outcomes of patients with CAP, and on the future research scenarios, with also a specific focus on COVID-19.

Implications of the Immune Landscape in COPD and Lung Cancer: Smoking Versus Other Causes

Cigarette smoking is reported in about one third of adults worldwide. A strong relationship between cigarette smoke exposure and chronic obstructive pulmonary disease (COPD) as well as lung cancer has been proven. However, about 15% of lung cancer cases, and between one fourth and one third of COPD cases, occur in never-smokers. The effects of cigarette smoke on the innate as well as the adaptive immune system have been widely investigated. It is assumed that certain immunologic features contribute to lung cancer and COPD development in the absence of smoking as the major risk factor. In this article, we review different immunological aspects of lung cancer and COPD with a special focus on non-smoking related risk factors.

Age-associated phenotypic imbalance in TCD4 and TCD8 cell subsets: comparison between healthy aged, smokers, COPD patients and young adults

Background

COPD is associated with an abnormal lung immune response that leads to tissue damage and remodeling of the lung, but also to systemic effects that compromise immune responses. Cigarette smoking also impacts on innate and adaptative immune responses, exerting dual, pro- and anti-inflammatory effects. Previously, we showed that COPD patients presented accelerated telomere shortening and decreased telomerase activity, while, paradoxically, cigarette-smokers exhibited preserved telomerase activity and slower rate of telomere shortening.

Results

Here, we evaluated the naive, CM, EM and TEMRA subsets of TCD4 and TCD8 cells according to the expression of CCR7/CD45RA. We compared age-matched COPD patients, cigarette-smokers without clinical-laboratory evidence of pulmonary compromise, and healthy individuals. They were additionally compared with a group of young adults. For each subset we analysed the expression of markers associated with late differentiation, senescence and exhaustion (CD27/CD28/CD57/KLRG1/PD1). We show that COPD patients presented a drastically reduced naive cells pool, and, paradoxically, increased fractions of naive cells expressing late differentiation, senescence or exhaustion markers, likely impacting on their immunocompetence. Pronounced phenotypic alterations were also evidenced in their three memory T-cell subsets compared with the other aged and young groups, suggesting an also dysfunctional memory pool. Surprisingly, our smokers showed a profile closer to the Healthy aged than COPD patients. They exhibited the usual age-associated shift of naive to EM TCD4 and TCD8 cells, but not to CM or TEMRA T-cells. Nonetheless, their naive T-cells phenotypes were in general similar to those of the Youngs and Healthy aged, suggesting a rather phenotypically preserved subset, while the memory T-cells exhibited increased proportions of cells with the late-differentiation or senescence/exhaustion markers as in the Healthy aged.

Conclusion

Our study extends previous findings by showing that COPD patients have cells expressing a full range of late differentiated, senescent or exhausted phenotypes encompassing all TCD4 and TCD8 subsets, consistent with a premature immunosenescence phenotype. Surprisingly, the smokers group’s results suggest that moderate to heavy chronic cigarette smoking did not accelerate the pace of immunosenescence as compared with the Healthy aged.

Peripheral memory T-cell profile is modified in patients undergoing periodontal management

AIMS

T-cells are known to have a role in periodontitis, however, the effect of periodontal therapy on peripheral memory T-cells is unclear. This study evaluated variation in peripheral memory T-cells and red complex bacteria in sub-gingival plaque in patients undergoing periodontal management.

METHODS

Peripheral blood mononuclear cells and sub-gingival plaque were collected from 54 periodontitis patients at baseline, 3-, 6- and 12-months post-therapy and 40 healthy controls. Periodontitis patients were divided into treatment outcome (TxO) groups based on prevalence of sites with probing depth ≥5 mm as good (<10% of sites), moderate (10-20%) or poor (>20%) at study conclusion. Naïve (T_N -CCR7⁺ CD45RA⁺ ), central memory (T_CM -CCR7⁺ CD45RA^- ), effector memory (T_EM -CCR7^- CD45RA^- ) and effector memory T-cells re-expressing CD45RA (T_EMRA -CCR7^- CD45RA⁺ ) were phenotyped using flow cytometry in CD4⁺ , CD8⁺ , CD4⁺ CD8⁺ and CD4^- CD8^- T-cells and red complex bacteria were quantified using qPCR.

RESULTS

At baseline, periodontitis subjects had significantly greater mean probing depths and Porphyromonas gingivalis proportions, lower T_N but higher CD4⁺ T_CM , CD8⁺ T_CM , CD4⁺ CD8⁺ T_EM and CD4^- CD8^- T_EM cell proportions compared to health. Periodontal therapy decreased mean probing depths, P. gingivalis proportions, T_EM and CD4⁺ and CD8⁺ T_CM cells, but increased T_N and CD4⁺ and CD8⁺ T_EMRA cells. The T-cell profile in the good TxO group showed therapy-related changes in CD4⁺ T_EM , and CD8⁺ T_N and T_EM cells, whereas, no changes were observed in the poor TxO group.

CONCLUSION

Management and the reduction in red complex bacteria were associated with changes in peripheral memory T-cells in periodontitis.

Do Smoking and Socioeconomic Factors Influence Imaging Outcomes in Axial Spondyloarthritis? Five-Year Data From the DESIR Cohort

Objective

To investigate the relationship between smoking and imaging outcomes over 5 years in axial spondyloarthritis (SpA) and to assess whether socioeconomic factors influence these relationships.

Methods

Axial SpA patients from the Devenir des Spondylarthropathies Indifferérenciées Récentes cohort were included. The following 4 imaging outcomes were assessed by 3 central readers at baseline, 2 years, and 5 years: spine radiographs (using the modified Stoke Ankylosing Spondylitis Spine Score [mSASSS]), sacroiliac (SI) joint radiographs (using the modified New York criteria), magnetic resonance imaging (MRI) of the spine (using the Spondyloarthritis Research Consortium of Canada [SPARCC] score), and MRI of the SI joint (using the SPARCC score). The explanatory variable of interest was smoking status at baseline. Interactions between smoking and socioeconomic factors (i.e., job type [blue‐collar or manual work versus white‐collar or nonmanual work] and education [low versus high]) were first tested, and if significant, analyses were run using separate strata. Generalized estimating equations models were used, with adjustments for confounders.

Results

In total, 406 axial SpA patients were included (52% male, 40% smokers, and 18% blue collar). Smoking was independently associated with more MRI‐detected SI joint inflammation at each visit over the 5 years, an effect that was seen only in patients with blue‐collar professions (β = 5.41 [95% confidence interval (95% CI) 1.35, 9.48]) and in patients with low education levels (β = 2.65 [95% CI 0.42,4.88]), using separate models. Smoking was also significantly associated with spinal inflammation (β = 1.69 [95% CI 0.45, 2.93]) and SI joint damage (β = 0.57 [95% CI 0.18, 0.96]) across all patients, irrespective of socioeconomic factors and other potential confounders.

Conclusion

Strong associations were found between smoking at baseline and MRI‐detected SI joint inflammation at each visit over a time period of 5 years in axial SpA patients with a blue‐collar job or low education level. These findings suggest a possible role for mechanical stress amplifying the effect of smoking on axial inflammation in axial SpA.

The impact of allergies and smoking status on nasal mucosa of hypertrophied turbinates - an immunohistologic analysis

Background: Allergies and smoking are common reasons for nasal mucosa inflammations, which in turn, cause nasal obstructions. Nevertheless, the impact of coexisting allergies and smoking on nasal mucosa inflammation has not been studied.Objectives: To study the impact of smoking with relation to allergies on nasal mucosa histology and to characterize an immunologic profile using immunohistochemical (IHC) staining.Methods: A cross-sectional study. Nasal biopsies of inferior turbinates from smokers with different allergic statuses were compared. Demographics, comorbidities, histologic, and immunohistochemical (IHC) staining of CD3, CD68, CD 20, and CD138 receptors were compared and analyzed.Results: A total of 53 patients were included, of which 20 (37.7%) were smokers, and 20 (37.7%) had allergic backgrounds. Smokers, both allergic and non-allergic, demonstrated reduced edema compared to the control group (p Value = 0.034) and significantly lower eosinophil density in the stroma compared to the allergic nonsmokers' group (p Value = 0.04). Smokers had a significant negative correlation between the number of cigarettes per day and the expression of CD20 in the stroma (-0.452, p Value = 0.045) and the epithelium (-0.432, p Value = 0.057) in IHC staining. Allergic smokers had a negative correlation (-0.705, p Value = 0.023) between the number of cigarettes per day and the CD68 marked cell expression in the epithelium.Conclusion: The coexistence of an allergic background and smoking alters known immunologic responses within the nasal mucosa. Smoking may have an immunosuppressive role in the nasal mucosa in both innate and humoral immune systems.

Pack-year Smoking Associated with Poorer Functional Status, Worsened Spinal Mobility and More Radiological Damages

Introduction: To study the dose-response relationship between smoking and axial Spondyloarthritis (axSpA) disease outcome.

Method: One hundred and sixty participants with axSpA were recruited from a single rheumatology center. All of them fulfilled the classification criteria for axSpA by the Assessment of SpondyloArthritis International Society (ASAS). Clinical, demographic and biochemical data was collected. Participants were asked for detailed smoking histories including past and current smoking, smoking duration and quantity. Radiographs of cervical and lumbar spine were performed for modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) and modified New York (MNY) criteria for radiological sacroiliitis. Ankylosing Spondylitis Disease Activity Score (ASDAS) was calculated based on C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Univariate and multivariate regression models were performed to determine the associations between pack-year smoking and different disease outcomes.

Results: Among the participants, 62 (38.7%) were either current (N [Formula: see text] 39) or former smokers (N [Formula: see text] 23). Ex-smokers quit smoking by 18.8 ± 12.4 years. The mean pack-year for patients who had ever smoked was 19.4 ± 23.1. In univariate analyses, pack-year smoking was associated with BASFI (p <0.001), modified Schober test (p [Formula: see text] 0.01) and mSASSS (p <0.001). Multivariate regression models showed independent dose-response associations between pack-year of smoking and BASFI (SC 0.23; 95% CI 0.01 to 0.06; p [Formula: see text] 0.004), modified Schober test (SC −0.16; 95% CI −0.03 to 0.00; p [Formula: see text] 0.049) and mSASSS (SC 0.22; 95% CI 0.09 to 0.47; p [Formula: see text] 0.01).

Conclusion: In Chinese axSpA patients, pack-year smoking was independently associated with poorer functional status, worsened spinal mobility and more radiological damages. Smoking cessation should be encouraged in patients with axSpA.

Tobacco Smoke Induces and Alters Immune Responses in the Lung Triggering Inflammation, Allergy, Asthma and Other Lung Diseases: A Mechanistic Review

Many studies have been undertaken to reveal how tobacco smoke skews immune responses contributing to the development of chronic obstructive pulmonary disease (COPD) and other lung diseases. Recently, environmental tobacco smoke (ETS) has been linked with asthma and allergic diseases in children. This review presents the most actual knowledge on exact molecular mechanisms responsible for the skewed inflammatory profile that aggravates inflammation, promotes infections, induces tissue damage, and may promote the development of allergy in individuals exposed to ETS. We demonstrate how the imbalance between oxidants and antioxidants resulting from exposure to tobacco smoke leads to oxidative stress, increased mucosal inflammation, and increased expression of inflammatory cytokines (such as interleukin (IL)-8, IL-6 and tumor necrosis factor α ([TNF]-α). Direct cellular effects of ETS on epithelial cells results in increased permeability, mucus overproduction, impaired mucociliary clearance, increased release of proinflammatory cytokines and chemokines, enhanced recruitment of macrophages and neutrophils and disturbed lymphocyte balance towards Th2. The plethora of presented phenomena fully justifies a restrictive policy aiming at limiting the domestic and public exposure to ETS.

The Effects of Firsthand and Secondhand Cigarette Smoking on Immune System Cells and Antibodies in Saudi Arabian Males

Firsthand and, to a lesser degree, secondhand tobacco smoking are considered the greatest causes of preventable illnesses and premature death worldwide. Firsthand and secondhand smoking have adverse consequences on the immune system, although these effects are not fully understood. A few serological studies have been done on firsthand and secondhand smokers in Saudi Arabia. The present study investigates the effects of firsthand and secondhand smoking on the immune system of randomly chosen male firsthand (50 subjects) and secondhand (50 subjects) cigarette smokers, residing in Jeddah, Saudi Arabia, with an age range of 20-40 years. Firsthand smokers were categorized according to the number of cigarettes smoked daily (frequency of smoking). Blood samples were collected and differential complete blood counts, cotinine concentrations, and antibodies (IgG, IgM, and IgA) concentrations were determined. Additionally, T, B, NK, CD4+ and CD8+ cells counts and percentages were determined. Compared to secondhand smokers, firsthand smokers showed a highly significantly higher mean cotinine concentration and a highly significantly lower mean IgA concentration. Additionally, Secondhand smokers had significantly higher mean lymphocyte count and CD4+/CD8+ ratio, and significantly lower mean basophil and NK cells counts. All other parameters showed no significant differences between firsthand and secondhand smokers and there were no differences between the frequency of smoking categories for the firsthand smokers. Therefore, The results show suggest that passive and active smoking have different immunological effects since IgA levels and some white blood cells counts were different in firsthand and secondhand smokers.

Effects of Cigarette Smoking on Transplant Survival: Extending or Shortening It?

Cigarette smoking (CS) regulates both innate and adaptive immunity and causes numerous diseases, including cardiovascular, respiratory, and autoimmune diseases, allergies, cancers, and transplant rejection. Therefore, smoking poses a serious challenge to the healthcare system worldwide. Epidemiological studies have always shown that CS is one of the major risk factors for transplant rejection, even though smoking plays redundant roles in regulating immune responses. The complex roles for smoking in immunoregulation are likely due to molecular and functional diversities of cigarette smoke components, including carbon monoxide (CO) and nicotine. Especially, CO has been shown to induce immune tolerance. Although CS has been shown to impact transplantation by causing complications and subsequent rejection, it is overlooked whether CS interferes with transplant tolerance. We have previously demonstrated that cigarette smoke exposure reverses long-term allograft survival induced by costimulatory blockade. Given that CS impacts both adaptive and innate immunity and that it hinders long-term transplant survival, our perspective is that CS impacts transplant tolerance. Here, we review impacts of CS on major immune cells that are critical for transplant outcomes and propose the cellular and molecular mechanisms underlying its effects on alloimmunity and transplant survival. Further investigations are warranted to fully understand why CS exerts deleterious rather than beneficial effects on transplant survival even if some of its components are immunosuppressive.

Impacts of cigarette smoking on immune responsiveness: Up and down or upside down?

Cigarette smoking is associated with numerous diseases and poses a serious challenge to the current healthcare system worldwide. Smoking impacts both innate and adaptive immunity and plays dual roles in regulating immunity by either exacerbation of pathogenic immune responses or attenuation of defensive immunity. Adaptive immune cells affected by smoking mainly include T helper cells (Th1/Th2/Th17), CD4+CD25+ regulatory T cells, CD8+ T cells, B cells and memory T/B lymphocytes while innate immune cells impacted by smoking are mostly DCs, macrophages and NK cells. Complex roles of cigarette smoke have resulted in numerous diseases, including cardiovascular, respiratory and autoimmune diseases, allergies, cancers and transplant rejection etc. Although previous reviews have described the effects of smoking on various diseases and regional immunity associated with specific diseases, a comprehensive and updated review is rarely seen to demonstrate impacts of smoking on general immunity and, especially on major components of immune cells. Here, we aim to systematically and objectively review the influence of smoking on major components of both innate and adaptive immune cells, and summarize cellular and molecular mechanisms underlying effects of cigarette smoking on the immune system. The molecular pathways impacted by cigarette smoking involve NFκB, MAP kinases and histone modification. Further investigations are warranted to understand the exact mechanisms responsible for smoking-mediated immunopathology and to answer lingering questions over why cigarette smoking is always harmful rather than beneficial even though it exerts dual effects on immune responses.

Distinctive Regulatory T Cells and Altered Cytokine Profile Locally in the Airways of Young Smokers with Normal Lung Function

Smoking influences the immune system in different ways and, hypothetically, effects on pulmonary effector and regulatory T cells emerge as potentially detrimental. Therefore, we characterized the frequencies and characteristics of CD4+ and CD8+ T cell subsets in the blood and lungs of young tobacco smokers. Bronchoalveolar lavage (BAL) and peripheral blood were obtained from healthy moderate smokers (n = 18; 2–24 pack-years) and never-smokers (n = 15), all with normal lung function. Cells were stimulated ex vivo and key intracellular cytokines (IFNγ, IL-17, IL-10 and TNFα) and transcription factors (Foxp3, T-bet and Helios) were analyzed using flow cytometry. Our results indicate that smoking is associated with a decline in lung IL-17+ CD4+ T cells, increased IFNγ+ CD8+ T cells and these alterations relate to the history of daily cigarette consumption. There is an increased fraction of Foxp3+ regulatory T cells being Helios- in the lungs of smokers. Cytokine production is mainly confined to the Helios- T cells, both in regulatory and effector subsets. Moreover, we detected a decline of Helios+Foxp3- postulated regulatory CD8+ T cells in smokers. These alterations in the immune system are likely to increase risk for infection and may have implications for autoimmune processes initiated in the lungs among tobacco smokers.

Cluster of differentiation 4+ cell count mean value, reference range and its influencing factors in Human Immunodeficiency Virus-seronegative pregnant women in Lagos

Background:

Immunity in pregnancy is physiologically compromised and this may affect cluster of differentiation four (CD4) count levels. It is well established that several factors affect CD4 count level in pregnancy. This study aims to determine the effects of maternal age, gestational age, parity and level of education as they influence CD4 count in pregnancy and also to determine the mean and reference range of CD4 count in pregnancy in Lagos, Nigeria.

Materials and Methods:

A descriptive cross-sectional study was carried out at Ante-natal clinics in Lagos State, Nigeria. About 5 mls of blood was collected into Ethylene Diamine Tetracetic Acid (EDTA) bottles from HIV-negative pregnant women in various gestational ages of pregnancy. CD4+ cell count and full blood count of all samples were done within 3 hours of collection. The descriptive data was given as means ± standard deviation (SD). Pearson's chi-squared test and correlation were used for analytical assessment.

Results:

A total of 74 pregnant women were recruited. The age range was 19–41 years and a mean age of 30.42 ± 5.34 years. The CD4+ cell count was not statistically significant when compared with participants ages P = 0.417, neither with gestational ages P = 0.323, nor with parity P = 0.247 nor level of education P = 0.96. An overall mean CD4+ cell count was 771.96 ± 250 cells/μl and the range was 193–1370 cells/μl.

Conclusion:

Maternal age, gestational age, parity and level of education had no significant effects on CD4+ cell count levels in pregnancy. The mean CD4+ cell count of HIV-negative pregnant women in Lagos is 771.96 ± 250 cells/μl.

Smoking is not associated with autoantibody production in systemic lupus erythematosus patients, unaffected first-degree relatives, nor healthy controls

OBJECTIVE

The objective of this paper is to examine whether smoking is associated with autoantibody production in systemic lupus erythematosus (SLE) patients, unaffected first-degree relatives (FDR) of individuals with SLE--a group at increased risk of developing SLE--or unaffected, unrelated controls.

METHODS

Detailed demographic, environmental, clinical, and therapeutic information was collected by questionnaire on 1242 SLE patients, 981 FDRs, and 946 controls in the Lupus Family Registry and Repository; a blood sample was obtained. All sera were tested for multiple lupus autoantibodies by immunofluorescence and luminex bead-based assays. Generalized estimating equations, adjusting for age, gender, and ethnicity and accounting for correlation within families, were used to assess smoking status with the dichotomous outcome variables of positivity for SLE status, positivity of ANA by immunofluorescence (≥1:120), positivity for ≥1 autoantibody by the luminex assay, and positivity for each of the 11 autoantibodies.

RESULTS

Current smoking was associated with being positive for ≥1 autoantibody (excluding ANA) (adjusted OR = 1.53, 95% CI 1.04-2.24) in our subjects with SLE. No association was observed in unaffected FDRs or healthy controls. Former smoking was associated with anti-Ro/SS-A60 in our unaffected FDRs. There was an increased association with anti-nRNP A seropositivity, as well as a decreased association with anti-nRNP 68 positivity, in current smokers in SLE subjects.

CONCLUSIONS

No clear association between smoking status and individual autoantibodies was detected in SLE patients, unaffected FDRs, nor healthy controls within this collection. The association of smoking with SLE may therefore manifest its risk through mechanisms outside of autoantibody production, at least for the specificities tested.

Cigarette smoke-induced effects on bone marrow B-cell subsets and CD4+:CD8+ T-cell ratios are reversed by smoking cessation: influence of bone mass on immune cell response to and recovery from smoke exposure

Cigarette smoking adversely affects the immune system, and is a risk factor for developing osteoporosis. How smoking contributes to osteoporosis is unclear, but since lymphocytes help maintain bone homeostasis and lymphocyte depletion results in bone loss, one potential mechanism for how smoke exposure promotes osteoporosis is by reducing bone marrow lymphocytes. Since the risk for developing osteoporosis is reportedly greater in smokers with polymorphisms in LRP5, a gene involved in canonical Wnt signaling that regulates bone metabolism, smoking-induced effects on lymphocytes may be influenced by Lrp5 functionality. To test these possibilities, we examined how the duration and cessation of cigarette smoke exposure affects lymphocyte distribution and function in normal mice and mice predisposed to low or high bone mass due to disruption or mutation of Lrp5. We find that, independent of genotype, mice exposed to cigarette smoke for 3-12 weeks showed a significant reduction in bone marrow B220(+)CD43(-) B cells and splenic transitional T1 B cells, and exhibited a splenic CD4(+):CD8(+) T-cell ratio that was skewed toward CD8(+) T cells. Smoke exposure had little or no effect on other lymphocyte subsets or on lymphocyte function ex vivo. Interestingly, these differences were no longer apparent after 6 weeks without smoke exposure, except in mice with high bone mass where bone marrow B220(+)CD43(-) B cells failed to fully recover. These data provide the first evidence that smoke exposure reduces bone marrow B cells, providing a plausible mechanism for how smoking contributes to osteoporosis.

Effects of tobacco smoke on immunity, inflammation and autoimmunity

Smoking is a central factor in many pathological conditions. Its role in neoplasm, lung and cardiovascular diseases has been well established for years. However it is less acknowledged the cigarette smoking affects both the innate and adoptive immune arms. Cigarette smoke was shown to augment the production of numerous pro-inflammatory cytokines such as TNF-alpha, IL-1, IL-6, IL-8 GM-CSF and to decrease the levels of anti-inflammatory cytokines such as IL-10. Tobacco smoke via multiple mechanisms leads to elevated IgE concentrations and to the subsequent development of atopic diseases and asthma. Cigarette smoke has also been shown activate in many ways macrophage and dendritic cell activity. While it is better evident how cigarette smoke evokes airway diseases more mechanisms are being revealed linking this social hazard to autoimmune disorders, for instance via the production of antibodies recognizing citrullinated proteins in rheumatoid arthritis or by the elevation of anti-dsDNA titers in systemic lupus erythematosus. The current review underlines the importance of smoking prevention and eradication not only in respiratory disorders but also in autoimmune conditions as well.

Psychologically adverse work conditions are associated with CD8+ T cell differentiation indicative of immunesenescence

Numerous studies have demonstrated associations between psychosocial stress and indices of poor health, and much research is now dedicated to identifying the responsible biological mechanisms. The current study examined the hypothesis that stress may impact health by promoting immunesenescence. Participants were 537 factory workers (89% male; mean age 44; range 18-65years). Blood was analyzed for two components of the aging 'immune risk phenotype': the number and proportion of late-differentiated (CD27-CD28-) CD8 T cells (CTLs) and CD4:CD8 ratio. Psychological assessment focussed on work-related stressors which have previously been found to predict morbidity and mortality. This assessment included measures of work load, effort-reward imbalance, and social support at work. High levels of job stress (low reward, high effort-reward imbalance) and low social support at work were associated with a significantly lower CD4:CD8 ratio. Also, the number of CD27-CD28- CTLs was 30% to 50% higher in employees classified in the highest tertile of each stress parameter as compared to employees in the corresponding lowest tertile (p<.01). These associations withstood adjustment for a wide range of demographic, life style, medical, and socio-economic indicators. The associations between CTL phenotype and low social support became stronger with increasing age. These results suggest that psychosocial stress may contribute to immunological aging. Prospective studies should address the long-term consequences of these associations for healthy aging.

Factors associated with CD4 lymphocyte counts in HIV-negative Senegalese individuals

CD4+ lymphocytes are a primary target of the human immunodeficiency virus (HIV), and CD4 counts are one of the factors used to measure disease progression in HIV-positive individuals. CD4 counts vary in uninfected individuals and across populations due to a variety of demographic, environmental, immunological and genetic factors that probably persist throughout the course of HIV infection. This study sought to determine reference levels and identify factors that influence lymphocyte counts in 681 HIV-uninfected adults in Senegal, where residents are exposed to a variety of infectious diseases and other conditions that may affect CD4 counts. Lymphocyte counts were assessed in commercial sex workers, symptomatic men and women presenting to the University of Dakar infectious disease clinic for out-patient care and women seeking family planning services. CD4 and CD3 lymphocyte counts differed between the four study groups (P < 0.01). Men had the lowest mean CD4 count (711.6 cells/microl), while commercial sex workers had the highest levels (966.0 cells/microl). After adjustment for age and other behavioural and clinical factors, the difference in CD4 counts between the three groups of women did not remain. However, both gender and smoking were associated independently with CD4 counts, as men maintained lower mean CD4 counts (beta = -156.4 cells/microl, P < 0.01) and smokers had higher mean CD4 counts (beta = 124.0 cells/microl, P < 0.01) than non-smokers in multivariable analyses. This study is the first to explore factors that may influence CD4 levels in Senegal and to estimate baseline CD4 levels among HIV-negatives, information that may guide clinicians in interpreting CD4 counts.

Systemic effects of smoking

Smoking is one of the major lifestyle factors influencing the health of human beings. Life-long cigarette smokers have a higher prevalence of common diseases such as atherosclerosis and COPD with significant systemic impact. The present review evaluates current knowledge concerning possible pathways through which cigarette smoking can affect human health, with special focus on extrapulmonary effects. Long-term smoke exposure can result in systemic oxidants-antioxidants imbalance as reflected by increased products of lipid peroxidation and depleted levels of antioxidants like vitamins A and C in plasma of smokers. A low-grade systemic inflammatory response is evident in smokers as confirmed by numerous population-based studies: elevated levels of C-reactive protein (CRP), fibrinogen, and interleukin-6, as well as increased counts of WBC have been reported. Furthermore, rheologic, coagulation and endothelial function markers like hematocrit, blood and/or plasma viscosity, fibrin d-dimer, circulating adhesion molecules (intracellular adhesion molecule-1, selectins), tissue plasminogen activator antigen, and plasminogen activator inhibitor type I are altered in chronic cigarette smokers. Although most of smoking-induced changes are reversible after quitting, some inflammatory mediators like CRP are still significantly raised in ex-smokers up to 10 to 20 years after quitting, suggesting ongoing low-grade inflammatory response persisting in former smokers. New longitudinal epidemiologic and genetic studies are required to evaluate the role of smoking itself and possible gene/environment interplay in initiation and development of smoking-induced common diseases affecting humans.

The effects of tobacco smoking and rheumatoid factor seropositivity on disease activity and joint damage in early rheumatoid arthritis

OBJECTIVE

To study the effect of tobacco smoking and rheumatoid factor (RF) isotypes on disease activity and joint damage in early rheumatoid arthritis (RA).

METHODS

One hundred early RA patients were followed prospectively for 2 yr. They were evaluated at recruitment and at 6 and 24 months. Sociodemographic information included smoking history, and radiographs of hands and feet were obtained. RF was monitored by IgM- and IgA-specific RF enzyme-linked immunosorbent assay and by agglutination, and serial measurements were also obtained for C-reactive protein. The influence of tobacco smoking and RF positivity on disease outcome was evaluated using multivariate analysis. Covariates for the regression analysis included sex, age, coffee consumption and IgA-RF positivity.

RESULTS

A gradient of increase in disease activity was observed from never smokers to former smokers to current smokers during the 2 yr of observation, defined by number of swollen joints (SJC), tender joints (TJC) and visual analogue scale for pain (P<0.001, P=0.02 and P=0.005, respectively), but smoking status did not influence radiological progression. Ever smokers were more often IgA RF positive (P<0.05). IgA RF-positive patients had more active disease (SJC P=0.002, TJC P=0.01) and showed more radiological progression (P<0.0001) compared with IgA RF-negative patients. Of the RF-positive patients 22% had elevated IgM RF without IgA RF and these patients showed similar disease activity and radiological joint progression to the RF-negative patients. None of these associations were explained by possible confounders.

CONCLUSION

Tobacco smoking has an adverse effect on patients with early RA and this is possibly immunologically mediated. IgM RF does not predict poorer prognosis in RA unless it is associated with a concomitant elevation of IgA RF.

Smoking influences the immunological architecture of the human larynx

Little is known about the effects of demographic and lifestyle factors on laryngeal mucosal immunology. Pinch biopsies of laryngeal mucosa were studied from 63 patients without laryngeal disease. Areas of positive staining for HLA-DR, HLA-DQ, HLA-DP, CD45, CD45RA, CD45RO, CD4, CD8, and CD79 were calculated. Patients were stratified according to gender and smoking status. Analysis of covariance showed current cigarette smokers had increased numbers of CD4+ T cells and there was an association between older age and greater CD4+ T cell numbers in both epithelium and lamina propria. Older age and female gender were associated with decreased lamina propria CD4+ CD45RO+ T cells and an increase in CD4+ CD45RO- T cells. T cell populations in the larynx may therefore be influenced by smoking, age and gender. We hypothesize that smoking induces changes in normal immunological function of the larynx, which may contribute to the etiology of inflammatory disease and cancer.

Systemic CD4+ T-cell activation is correlated with FEV1 in smokers

The inflammation of the lungs in chronic obstructive pulmonary disease (COPD) is characterised by increased numbers of macrophages, neutrophils and T-cells. Decline in lung function in these patients has been correlated to the number of CD8+ T-cells present in the lung as well as to a decline in the ratio of CD4+/CD8+ T-cells. Although systemic components are likely to be present, circulating lymphocyte populations in COPD patients have not been well characterised. This study aimed at correlating lung function to expression of five different T-cell activation markers on peripheral blood CD4+ and CD8+ T-cells in COPD patients and matched smokers. Furthermore, proportions of lymphocyte populations and degree of systemic T-cell activation in COPD patients were compared to that in smokers and never-smokers. Peripheral blood lymphocytes from six never-smokers, eight smokers and 17 smokers with COPD were analysed using flowcytometry. The number of lymphocytes per millilitre was higher in smokers than in never-smokers. No differences were found between the three groups in regard to proportions of lymphocyte populations, but the number of CD4+ T-cells in smokers was higher than in both never-smokers and COPD patients. The degree of T-cell activation was similar in all patient groups; however, a clear correlation between CD69 expression on CD4+ T-cells and lung function (FEV(1)% of predicted) was found when examining current smokers, with or without COPD. Elevated numbers of CD69+ CD4+ T-cells in blood thus seem to be protective against airway obstruction in smokers while still exposed to cigarette smoke, the main inducer of COPD.

Relationships of differential leukocyte and lymphocyte subpopulations with carotid atherosclerosis in elderly men

To examine the relationship between systemic immune status and carotid atherosclerosis in elderly men, differential leukocyte counts and lymphocyte subpopulations were measured in 557 apparently healthy Japanese men aged 60-75 years. Each individual also underwent high-resolution ultrasonography for measurement of intima-media thickness (IMT) of the common carotid arteries. The increased numbers of circulating lymphocyte subpopulations, including memory T cells (CD4+CD45RO+T cells) and late-phase activated B cells (CD19+CD80+B cells) correlated significantly and positively with the mean IMT of the common carotid artery after adjustment for age, smoking, and other cardiovascular risk factors. The positive associations of CD19+CD80+B and CD4+CD45RO+ T cell counts with mean IMT were more evident among nonsmokers, hypertensives, and men with lower HDL-cholesterol levels. The present epidemiological study provided the evidence that alterations in lymphocyte subpopulations, in particular memory T cells and late-phase activated B cells concur with carotid atherosclerosis among free-living elderly men.

Association of lymphocyte sub-populations with clustered features of metabolic syndrome in middle-aged Japanese men

To examine the relationship between altered cellular immune status and clustered features of the metabolic syndrome, we measured body mass index (BMI), serum concentrations of high-density lipoprotein-cholesterol, triglycerides, fasting plasma glucose, and blood pressure levels as well as differential leukocyte counts and lymphocyte sub-populations among 439 apparently healthy Japanese men aged 35-60 years. The components of the metabolic syndrome were defined based on the following criteria: BMI >/=25.0 kg/m(2), fasting plasma glucose >/=6.11 mmol/l, systolic blood pressure >/=130 mmHg and/or diastolic blood pressure >/=85 mmHg, high-density lipoprotein (HDL)-cholesterol <1.03 mmol/l, and fasting triglyceride >/=1.69 mmol/l. Counts of total leukocyte, total lymphocyte, CD3 + T cell, CD4 + T cell, and CD4 + CD45RO + T cell significantly correlated with the number of components of the metabolic syndrome (0, 1, 2, and 3+) after adjustment for age and smoking status. These findings were more evident among smokers than among non-smokers. The counts of total leukocytes, total lymphocytes and more specifically memory (CD4 + CD45RO + T) cells were elevated with clustered features of the metabolic syndrome in middle-aged men, which suggest the involvement of altered cellular immune status in the pathogenesis of atherosclerosis.

Young male smokers have altered platelets and endothelium that precedes atherosclerosis

BACKGROUND

Cigarette smoking results in abnormalities of platelets and endothelium with platelet dysfunction implicated in vascular complications. Healthy endothelium plays a pivotal role in regulating hemostasis via the inhibition of platelet activation and aggregation. Thus, we examined if platelet dysfunction correlated with serum vWF levels-a circulating marker of endothelial dysfunction.

MATERIALS AND METHODS

We tested this hypothesis in young male smokers. The parameters of platelet function tested included: CD62/CD63; Glycoprotein (GP) IIb/IIIa; Platelet function analzyer (PFA) studies, platelet aggregometry, flow assessment of platelet microparticles, platelet-leukocyte interactions and receptor numbers. Endothelial dysfunction was assessed with serum von Willebrand Factor (vWF).

RESULTS

There was a significant increase in platelet CD62 receptor expression and aggregation with an associated delay in time to aggregation using PFA. Endothelial dysfunction was represented by higher serum levels of von Willebrand Factor. All other platelet parameters tested were within the standardized reference range.

CONCLUSIONS

These initial data suggests that anti-platelet therapy may have a role in reduction of platelet activation and aggregation in young smokers and possibly alter vascular endothelial abnormalities.

Panic disorder and immunity: few effects on circulating lymphocytes, mitogen response, and NK cell activity

Altered immune measures are commonly found in major depression (MD), however, less is known about the immune system in anxiety disorders. We examined quantitative and functional in vitro immune measures in patients with panic disorder (PD), which is often comorbid with MD. Fourteen otherwise healthy medication-free adults (ages 23-49; 11 female) meeting SCID-UP DSM-IIIR criteria for PD with agoraphobia and without current MD, were compared with 14 subjects free of PD, MD, or other major psychiatric disorders, matched by gender, age, and racial background. PD was associated with decreased percentage (p<.03) and total (p<.03) circulating CD19+ B lymphocytes, but no differences in other enumerative lymphocyte measures. Mitogen responses (Con A, PHA, PWM) did not differ except for possibly decreased PHA in PD (p<.06). NK cell activity did not differ between PD and control subjects. The few immune measure changes in PD contrast with those found in MD, providing further evidence for the specificity of immune changes in psychiatric disorders.

Decreases of natural killer cells and T-lymphocyte subpopulations and increases of B lymphocytes following a 5-day occupational exposure to mixed organic solvents

The authors examined the effects of organic solvents on lymphocyte subpopulations in blood. Natural killer and T-lymphocyte subpopulations and B (CD19+) -lymphocytes were measured with flow cytometry in 16 male rotogravure printers on a Friday and on the following Monday. Numbers of all 3 subpopulations of natural killer cells (i.e., CD57+ CD16+, CD57- CD16+, and CD57+ CD16- cells), 2 subpopulations of T lymphocytes (CD4+ CD45RA+ and total CD8+ cells), and total lymphocytes on Friday were significantly fewer than those found on the following Monday. Conversely, the number of B lymphocytes on Friday was significantly larger than the number on Monday. The number of B lymphocytes was significantly correlated with blood toluene levels on Friday. The alteration in the number of CD57+ CD16+ NK cells from Friday to the following Monday was correlated inversely with the corresponding change in exposure level of toluene on Friday. The authors suggest that the effects of mixed organic solvents (primarily toluene) are recoverable decreases of natural killer cells and T lymphocytes and increases in B lymphocytes.