Effect of tobacco smoking on the functions of polymorphonuclear leukocytes

The role of cigarette smoking in periodontal disease and treatment outcomes of dental implant therapy

Tobacco smoking has been implicated in periodontal pathology through various mechanisms, including perturbations of the inflammatory and host responses to putative periodontal pathogens, alterations in the subgingival microbial communities, and a compromised healing potential of the tissues leading to imbalance of tissue homeostasis. This review provides the evidence for the relationship between cigarette smoking and periodontal disease in an attempt to explain possible mechanisms of how tobacco smoking may exert its negative effects on the periodontal tissues via systemic and localized pathways. Early and more recent studies explore cigarette smoking-induced changes in periodontal clinical indices; in subgingival microbial flora by employing traditional detection methods for selected microorganisms, in addition to modern techniques such as deep sequencing and bioinformatics analyses that are able to fully characterize the microbial communities; and in inflammatory and immune responses critically appraising study limitations and differences in study protocol designs. Periodontal treatment outcomes and implant therapy outcomes are reviewed in an attempt to shed light on possible mechanisms for the inferior treatment outcome noted in smokers. The potential harmful effects of passive smoking are also reviewed, providing evidence for the advantages of smoking cessation. Quitting cigarette smoking should be recommended by the dentist, and effort should be made to inform smokers about the negative effects of smoking on the periodontal status and implant therapy outcomes.

The Impact of Smoking on Early Postoperative Complications in Hand Surgery

PURPOSE

Smoking is a prevalent modifiable risk factor that has been associated with adverse postoperative outcomes across numerous surgical specialties. We examined the impact of smoking on 30-day complications in patients undergoing hand surgery procedures.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program data sets were queried for patients who underwent common hand surgery procedures from 2011 to 2016. Cohorts were divided into smoking and nonsmoking and compared in terms of demographic characteristics, comorbidities, and postoperative complications. Multivariable logistic regression models were used to control for demographic characteristics and comorbidities in assessing the association between smoking and postoperative infections as well as other major and minor complications.

RESULTS

We identified a cohort of 48,370 patients in the National Surgical Quality Improvement Program who underwent certain outpatient and inpatient hospital facility-based hand surgery procedures from 2011 to 2016. Up to 22% of these patients reported active smoking. Compared with nonsmokers, smokers were more likely to be younger and male and to have a lower body mass index. In addition, they were more likely to have a higher American Society of Anesthesiologists classification and to report dyspnea and chronic obstructive pulmonary disease. Multivariable logistic regression identified an independent association between smoking and major complications. Smoking was not significantly associated with minor complications. When regrouped by complication type, smoking was associated with infectious and wound healing complications. In subgroup analysis, smokers undergoing elective hand surgery had increased odds of wound healing complications but not major, minor, or infectious complications.

CONCLUSIONS

Smokers may be at a significantly higher odds of certain complications compared with nonsmokers. For patients undergoing the elective procedures evaluated in this study, perioperative smoking may increase the risk of wound-healing complications.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

Risk factors for chronic biofilm-related infection associated with implanted medical devices

BACKGROUND

The use of implanted medical devices is associated with a small but clinically important risk of foreign body infection. A key question is: why do some patients develop chronic infection associated with an implanted device, but most do not?

AIMS

The literature on patient-specific risk factors for chronic infections associated with five types of implants was surveyed to glean clues about the etiology of these infections.

SOURCES

Data were collected from 47 articles through calendar year 2017 for five categories of device-related infections: cardiovascular implantable electronic devices (CIEDs), hernia meshes, prosthetic hip and knee joints, prosthetic shoulder joints and breast implants.

CONTENT

Important risk factors include immunomodulation/steroid therapy, diabetes, smoking, and renal disease/haemodialysis-findings that point to a critical role of a compromised innate immune response in determining vulnerable subpopulations.

IMPLICATIONS

A model of biofilm-related device infection is presented that posits defects in the innate immune response both systemically and locally, in the immediate vicinity of an abiotic biomaterial. The limitations of in vitro and animal models of chronic device-related infections are discussed in this context as are implications for research and clinical practice.

Optimal approaches to preventing severe community-acquired pneumonia

Introduction: Community-acquired pneumonia (CAP) has the highest rate of mortality of all infectious diseases, especially among the elderly. Severe CAP (sCAP) is defined as a CAP in which intensive care management is required and is associated with an unfavorable clinical course. Areas covered: This review aims to identify prevention strategies for reducing the incidence of CAP and optimized management of sCAP. We highlight the main prevention approaches for CAP, focusing on the latest vaccination plans and on the influence of health-risk behaviors. Lastly, we report the latest recommendations about the optimal approach for sCAP when CAP has already been diagnosed, including prompt admission to ICU, early empirical antibiotic therapy, and optimization of antibiotic use. Expert opinion: Despite improvements in the diagnosis and treatment of sCAP, more efforts are needed to combat preventable causes, including the implementation and improvement of vaccine coverage, anti-tobacco campaigns and correct oral hygiene. Moreover, future research should aim to assess the benefits of early antimicrobial therapy in primary care. Pharmacokinetic studies in the target population may help clinicians to adjust dosage regimens in critically ill patients with CAP and thus reduce rates of treatment failure.

Cigarette smoke exposure redirects Staphylococcus aureus to a virulence profile associated with persistent infection

Tobacco smoking represents the leading preventable cause of death worldwide. Smoking is a recognised risk factor for several pathologies and is detrimental to host immune surveillance and defence. However, the impact of smoking on microbial residents of the nasopharyngeal cavity, in contact with cigarette smoke (CS), is lacking. Staphylococcus aureus is a major human pathogen that colonises the human nasopharynx and causes a wide range of infections. We investigated the impact of CS on specific virulence phenotypes important in S aureus pathogenesis. We observed strain-dependent differences following exposure to CS, namely growth inhibition, augmented biofilm formation, increased invasion of, and persistence within, bronchial alveolar epithelial cells. Additionally, we confirm the critical role of a functional accessory gene regulator (Agr) system in mediating increased biofilm development and host cell invasion and persistence following CS exposure. Furthermore, CS exposure resulted in reduced toxin production. Importantly, exposure of S aureus to CS accelerated the frequency of mutations and resulted in a significant increase in gentamicin-resistant small colony variant (SCV) formation. Mutational analysis revealed that CS induced SCVs emerge via the SOS response DNA mutagenic repair system. Taken together, our results suggest that CS redirects certain S aureus strains to a virulence profile associated with persistence.

Effect of tobacco smoking on the risk of developing community acquired pneumonia: A systematic review and meta-analysis

Aim

To summarise and quantify the effect of tobacco smoking on the risk of developing community acquired pneumonia (CAP) in adults.

Methods

We systematically searched MEDLINE, Embase, CINAHL, PsychINFO and Web of Science, from inception to October 2017, to identify case-control and cohort studies and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist. The review protocol was registered with the PROSPERO database (CRD42018093943). Study quality was assessed by the Newcastle-Ottawa Scale. Pooled odds ratios (ORs) or hazard ratios (HRs) were estimated using a random-effects model.

Results

Of 647 studies identified, 27 studies were included (n = 460,592 participants) in the systematic review. Most of the included studies were of moderate quality with a median score of six (IQR 6–7). Meta-analysis showed that current smokers (pooled OR 2.17, 95% CI 1.70–2.76, n = 13 studies; pooled HR 1.52, 95% CI 1.13–2.04, n = 7 studies) and ex-smokers (pooled OR 1.49, 95% CI 1.26–1.75, n = 8 studies; pooled HR 1.18, 95% CI 0.91–1.52, n = 6 studies) were more likely to develop CAP compared to never smokers. Although the association between passive smoking and risk of CAP in adults of all ages was not statistically significant (pooled OR 1.13, 95% CI 0.94–1.36, n = 5 studies), passive smoking in adults aged ≥65 years was associated with a 64% increased risk of CAP (pooled OR 1.64; 95% CI 1.17–2.30, n = 2 studies). Dose-response analyses of data from five studies revealed a significant trend; current smokers who smoked higher amount of tobacco had a higher risk of CAP.

Conclusion

Tobacco smoke exposure is significantly associated with the development of CAP in current smokers and ex-smokers. Adults aged > 65 years who are passive smokers are also at higher risk of CAP. For current smokers, a significant dose-response relationship is evident.

Tobacco smoke-induced immunologic changes may contribute to oral carcinogenesis

OBJECTIVE

The objective of this study was to determine if tobacco smoke (TS), a risk factor for cancers of the aerodigestive tract, may contribute to oral carcinogenesis, in part, by suppressing local immunity.

METHODS

Mice were placed in Plexiglas holders in which they breathed TS through the nose and mouth for 1 hour daily for 21 days. Control mice breathed room air in the same manner. One day after the last exposure, mice were immunized by application of oxazolone to each buccal mucosa. Control mice were mock immunized by application of vehicle alone. Five days later, all mice were challenged on the ears with oxazolone, and 24-hour ear swelling assessed as contact hypersensitivity.

RESULTS

Mice exposed to TS had a significantly smaller contact hypersensitivity response compared with controls. When subsequently reimmunized on the glabrous skin, mice originally primed through TS-exposed mucosa could not be fully immunized, indicating induction of immunologic tolerance by exposure to hapten through TS-perturbed mucosa. Immunocompetent mice exposed to TS in this manner and challenged by submucosal placement of a syngeneic malignant tumor had significantly increased tumor growth over time compared with controls. No difference in growth rate was observed when the experiment was performed with natural killer cell-deficient, SCID (severe combined immunodeficiency) mice. In addition, exposure of epidermal Langerhans cells in vitro to an aqueous extract of TS impaired their ability to undergo maturation and to present antigen to responsive T cells.

CONCLUSIONS

Immunologic changes induced in the oral cavity by exposure to TS may play a role in the development of oral cancers.

Active and passive smoking and fecundability in Danish pregnancy planners

OBJECTIVE

To investigate the extent to which fecundability is associated with active smoking, time since smoking cessation, and passive smoking.

DESIGN

Prospective cohort study.

SETTING

Denmark, 2007-2011.

PATIENT(S)

A total of 3,773 female pregnancy planners aged 18-40 years.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Self-reported pregnancy. Fecundability ratios (FRs) and 95% confidence intervals (CIs) were estimated using a proportional probabilities model that adjusted for menstrual cycle at risk and potential confounders.

RESULT(S)

Among current smokers, smoking duration of ≥10 years was associated with reduced fecundability compared with never smokers (FR, 0.85, 95% CI 0.72-1.00). Former smokers who had smoked ≥10 pack-years had reduced fecundability regardless of when they quit smoking (1-1.9 years FR, 0.83, 95% CI 0.54-1.27; ≥2 years FR, 0.73, 95% CI 0.53-1.02). Among never smokers, the FRs were 1.04 (95% CI 0.89-1.21) for passive smoking in early life and 0.92 (95% CI 0.82-1.03) for passive smoking in adulthood.

CONCLUSION(S)

Among Danish pregnancy planners, cumulative exposure to active cigarette smoking was associated with delayed conception among current and former smokers. Time since smoking cessation and passive smoking were not appreciably associated with fecundability.

Tobacco smoke-induced immunologic changes may contribute to oral carcinogenesis

OBJECTIVE

The objective of this study was to determine if tobacco smoke (TS), a risk factor for cancers of the aerodigestive tract, may contribute to oral carcinogenesis, in part, by suppressing local immunity.

METHODS

Mice were placed in Plexiglas holders in which they breathed TS through the nose and mouth for 1 hour daily for 21 days. Control mice breathed room air in the same manner. One day after the last exposure, mice were immunized by application of oxazolone to each buccal mucosa. Control mice were mock immunized by application of vehicle alone. Five days later, all mice were challenged on the ears with oxazolone, and 24-hour ear swelling assessed as contact hypersensitivity.

RESULTS

Mice exposed to TS had a significantly smaller contact hypersensitivity response compared with controls. When subsequently reimmunized on the glabrous skin, mice originally primed through TS-exposed mucosa could not be fully immunized, indicating induction of immunologic tolerance by exposure to hapten through TS-perturbed mucosa. Immunocompetent mice exposed to TS in this manner and challenged by submucosal placement of a syngeneic malignant tumor had significantly increased tumor growth over time compared with controls. No difference in growth rate was observed when the experiment was performed with natural killer cell-deficient, SCID (severe combined immunodeficiency) mice. In addition, exposure of epidermal Langerhans cells in vitro to an aqueous extract of TS impaired their ability to undergo maturation and to present antigen to responsive T cells.

CONCLUSIONS

Immunologic changes induced in the oral cavity by exposure to TS may play a role in the development of oral cancers.

Effects of Active and Passive Smoking on Ear Infections

Otitis media (OM) is one of the most frequent diseases in young children, causing to visit a physician, and also the most common indication for antibiotic prescription. The peak incidence and prevalence of OM is 6 to 18 months of age. In children, second-hand smoke (SHS) exposure is associated with upper and lower respiratory tract infections, such as acute otitis media (AOM), pneumonia, and bronchitis. Despite the overwhelming evidence of the role of SHS exposure on infant health, a very high proportion of children still continue to be exposed. This important relationship between all kinds of smoking and poor health may not be appreciated universally. With this article, we aim to review tobacco smoke exposure and OM connection. How this exposure may cause OM especially in young children? What can be done to prevent and to reduce the harmfull effects of tobacco smoking?

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.

Smoke exposure and ethanol ingestion modulate intrapulmonary polymorphonuclear leukocyte killing, but not recruitment or phagocytosis

BACKGROUND

People who smoke and abuse alcohol are uniquely susceptible to pulmonary infections caused by Streptococcus pneumoniae, the pneumococcus. The primary cellular defense against pneumococci within the lungs is the polymorphonuclear leukocyte (PMN). Cigarette smoke and ethanol (EtOH) are known to alter certain PMN functions, but little is known about their concurrent effects.

METHODS

Male Sprague-Dawley rats were exposed twice daily for 8 weeks to cigarette smoke (smoke-exposed) or room air (sham-exposed). During the final week of exposure, the rats were pair-fed a liquid diet containing either 36 or 0% EtOH calories. Polymorphonuclear leukocytes were prerecruited into the rats' lungs by transtracheal injection of lipopolysaccharide. Five hours later, the rats were infected transtracheally with S. pneumoniae, and PMN recruitment, phagocytosis, and bactericidal activity were quantified within their lungs. Chemokine levels were also measured in bronchoalveolar lavage fluids, lung homogenates, and sera.

RESULTS

Neither PMN recruitment nor phagocytic uptake of pneumococci was altered by EtOH ingestion or smoke exposure. Killing of the organisms, however, was significantly decreased in sham-exposed, but not smoke-exposed, rats ingesting EtOH. Parallel results were determined for serum cytokine-induced neutrophil chemoattractant-1 (CINC-1), with EtOH ingestion significantly decreasing the levels in sham-exposed, but not smoke-exposed, rats. Pulmonary levels of macrophage inflammatory protein-2 (MIP-2) and CINC-1 were highly elevated by the combination of EtOH and smoke.

CONCLUSIONS

One week of EtOH ingestion by rats impaired the ability of their PMNs to kill S. pneumoniae within their lungs. This was not due to decreased recruitment of the PMNs to the lungs or to diminished phagocytosis of intrapulmonary pneumococci. The addition of twice-daily cigarette smoke exposure to this short-term EtOH ingestion model restored PMN bactericidal ability to levels observed in the absence of either treatment. These EtOH-induced and smoke-induced alterations in PMN killing may be related to alterations in both pulmonary and systemic inflammatory chemokine levels.

Immunoglobulin G Fc(gamma) receptor expression on polymorphonuclear cells in bronchoalveolar lavage fluid of HIV-infected and HIV-seronegative patients with bacterial pneumonia

This study was designed to test the hypothesis that impaired neutrophil function might contribute to the development of bacterial pneumonia in patients with HIV-infection. Numbers of inflammatory cells and immunoglobulin G Fcgamma receptor (IgG FcgammaR) I, II, III levels were investigated in bronchoalveolar lavage (BAL) fluid of HIV-seronegative and HIV-infected patients with bacterial pneumonia. The 99 patients were classified into three groups: I: HIV-seronegative and pneumonia (n = 40); II: HIV-infected and pneumonia (n = 19); III: HIV-seronegative with other pulmonary diseases than pneumonia (n = 40). The results of groups I and II, II and III, and I and III were compared. The percentage of alveolar macrophages was significantly lower (group II vs. III: p = 0.005, group I vs. III: p = 0.001), that of neutrophils increased significantly in patients with pneumonia (group II vs. III: p = 0.02, group I vs. III: p = 0.01). Lymphocytes differed only between groups I and III (p = 0.04). Although only the expression of FcgammaRI was significantly higher in HIV-seronegative pneumonia patients compared to those without pneumonia (p = 0.01), the mean expression of all three receptors was lower in the HIV-infected group, with that of FcgammaRI approaching statistical significance. This report provides first evidence that altered FcgammaR expression on BAL neutrophils might contribute to the increased susceptibility of HIV-infected patients to bacterial pneumonia.

Smoking influences decision making in periodontal therapy: a retrospective clinical study

BACKGROUND

Mechanical periodontal therapy consists of a non-surgical course, followed by surgical treatment to eliminate or reduce remaining pathological pockets. Only if diligent mechanical therapy fails are additional measures considered. It has been documented that smoking interferes with the host defense mechanisms. This study addresses the question is meticulous non-surgical periodontal therapy equally successful in smokers and non-smokers? If not, is a thorough and cumbersome non-surgical approach in smokers worth undertaking?

METHODS

Thirty-five smokers and 35 non-smokers were selected retrospectively from a pool of 306 patients treated in a private practice over a 17-month period. All had at least 14 teeth present with 8 presenting with gingival pockets > or =6 mm. Non-surgical treatment was performed in 6 to 10 appointments and results were evaluated 6 to 12 weeks after therapy. Bleeding on probing sites with probing depths > or =5 mm were then considered for surgical treatment.

RESULTS

Before treatment smokers had statistically significantly higher mean percent of pockets 4 to 5 mm and > or =6 mm (40.36+/-10.65 and 26.51+/-11.95, respectively, compared to 30.38+/-7.57 and 20.42+/-10.03 for non-smokers) and showed significantly lower proportional reduction of these parameters with treatment (50.80+/-33.76 and 81.36+/-19.82 for pocket 4 to 5 mm and 6 mm, compared to 68.43+/-21.23 and 91.7+/-8.92 for nonsmokers). A multivariate analysis gave smoking, plaque control, and initial percent of sites > or =6 mm to be significant predictors of the percent of teeth in need of further therapy. In non-smokers, treatment was apparently successful in all tooth types with the exception of upper first and second molars (28.5% failure) and lower second molar (20% failure). In smokers, rates of further treatment needs were particularly high in the premolar-molar area in both jaws, ranging from 31.4% to 48.5% for an individual tooth type; 42.8% of smokers and 11.5% of non-smokers needed further treatment in 16% of their teeth (pretest probability). A decision analysis showed that for smokers with at least 1 of 5 sites > or =6 mm, one should initiate surgical treatment, rather than first treat non-surgically. If the point of indifference that the decision is correctly set at 95%, the pretest probability should be >12%. There is a higher risk that non-surgical therapy will fail, for instance if we lower the point of indifference to 60%, the pretest probability should be >31%.

CONCLUSIONS

It is concluded that smoking impairs healing after nonsurgical periodontal therapy. The decision analysis of this study questions the need for a thorough course of non-surgical treatment in smokers with advanced periodontal disease.

Cigarette smoking causes sequestration of polymorphonuclear leukocytes released from the bone marrow in lung microvessels

Studies from our laboratory have shown that chronic cigarette smoke exposure causes a neutrophilia associated with a shortening of the mean transit time of polymorphonuclear leukocytes (PMN) though the postmitotic pool of the marrow. The present study was designed to test the hypothesis that PMN newly released from bone marrow by smoke exposure preferentially sequestered in pulmonary microvessels. The thymidine analogue 5'-bromo-2'-deoxyuridine (BrdU) was used to label dividing PMN in the marrow of rabbits; their appearance in the circulation was measured using immunocytochemistry, and their sequestration in lung tissue was determined using standard morphometric techniques. Animals exposed to 11 d of cigarette smoke (n = 6) compared with sham-exposed control animals (n = 4) showed no increase in circulating PMN counts but showed an increase in both the percentage of band cells (smoking, 9.8 +/- 1.1% versus control, 5.5 +/- 0.9%; P < 0.05) and BrdU-labeled PMN (PMNBrdU) in the circulation (smoking, 10.8 +/- 0.6% versus control, 7.5 +/- 0.3%; P < 0.05). There were more PMN sequestered in the lungs of smoke-exposed animals (51.7 +/- 3.4 x 10(7)/ml tissue) than in those of control animals (25.1 +/- 1.8 x 10(7)/ ml tissue) (P < 0.05) and a higher percentage of these cells were PMNBrdU (smoking, 16.9 +/- 2. 3% versus control, 9.6 +/- 0.4%; P < 0.05). The percentage of PMNBrdU in the gravity-independent regions (11.7 +/- 1.9%) of the lung was higher than gravity-dependent regions (7.8 +/- 1.8%) in the smoke-exposure group (P < 0.05). Transmission electron microscopy showed pulmonary capillary endothelial damage with adherent PMN in the smoke-exposure group. We conclude that younger PMN released from the bone marrow by cigarette smoking preferentially sequestered in pulmonary microvessels and speculate that these PMN may contribute to the alveolar wall damage associated with smoke-induced lung emphysema.

Alterations of neutrophil oxidative burst by in vitro smoke exposure: implications for oral and systemic diseases

Alterations of neutrophil functions by tobacco products may play a central role in the pathogenesis of periodontal diseases and several smoking-related systemic diseases. In the present study, we examined the in vitro effects of cigarette smoke on neutrophils at times and concentrations that may be encountered during smoke exposure. We measured the level of smoke exposure in the in vitro system by measuring the levels of nicotine and comparing these to levels in the oral cavity in smokers before and after smoking. We examined both the unstimulated and stimulated release of 2 oxidative burst products: superoxide (O-2) and hydrogen peroxide (H2O2). Salivary washings were collected from 7 smokers (> 1 pack/day) before smoking a cigarette. Immediately after they smoked a cigarette, a second set of washings was collected. In vitro exposure to smoke involved incubating aliquots of neutrophils in phosphate-buffered saline for 1 to 5 minutes. Nicotine and cotinine levels were quantitated using gas chromatography, with detection by electron impact mass spectrometry. Peripheral neutrophils were isolated from medically healthy non-smoking volunteers via a double-density gradient technique and incubated in vitro with whole cigarette smoke for 0 to 5 minutes. Phorbol myristate acetate (PMA; 10(-7) M) was used to stimulate half of the cell aliquots. Superoxide generation was assessed through the superoxide dismutase (SOD) inhibitable reduction of ferricytochrome c. H2O2 production was assessed through the H2O2-dependent breakdown of dichlorofluorescin diacetate to its fluorophore and measured by flow cytometry. There was a marked elevation in salivary nicotine concentration from before smoking (mean: 80.8 ng) to after smoking (mean 1,685 ng/mL). In the in vitro smoke box system, there was a time-related elevation in nicotine from 1 to 5 minutes (50-->136 ng/mL). In PMA-stimulated cells exposed to smoke, there was a time-related inhibition of both superoxide and H2O2 production. However, in unstimulated cells exposed to smoke, there was a time-related increase in the release of superoxide and H2O2. A novel finding in unstimulated cells exposed to smoke was that there appeared to be 2 distinct populations of cells--one of "high" H2O2 producers and one of "low" H2O2 producers. The proportion of high H2O2 producers increased relative to smoke exposure. The relative production of H2O2 in the unstimulated high producers was comparable to PMA-stimulated cells at 5 minutes. This release of superoxide and H2O2 in unstimulated cells exposed to smoke may alter the pathogenic processes both in periodontal diseases and other systemic diseases.

Decreased leukocyte deformability after acute cigarette smoking in humans

Acute cigarette smoking increases the sequestration of neutrophils in the lungs of humans. This may be due to the delayed transit of cells in the pulmonary microcirculation, which may result from a reduction in cell deformability as suggested by in vitro studies of smoke-exposed neutrophils. In order to support this hypothesis we wished to determine if a reduction in leukocyte deformability could be measured in whole blood exposed to smoke in vitro or in vivo. Whole blood filterability, which largely reflects leukocyte deformability, was measured as the pressure developed by filtration of diluted whole blood through a micropore membrane. Whole blood filtration pressures did not change when blood was exposed to smoke in vitro or in venous blood after acute smoking in vivo. However, arterial blood sampled from chronic smokers during acute smoking showed a consistent reduction in leukocyte deformability associated with a small increase in plasma elastase. To assess whether these changes were induced by oxidants in cigarette smoke, we measured the levels of the antioxidant glutathione (GSH), erythrocyte (RBC) membrane fragility, and products of lipid peroxidation in plasma and RBC in blood exposed to smoke in vivo and in vitro. No change in RBC lipid peroxidation or membrane fragility could be detected after in vitro smoke exposure, possibly because of the high antioxidant capacity of the RBC. However, reduced blood GSH levels and increased levels of lipid peroxidation products were detected in plasma, reflecting oxidant stress. In contrast, we were unable to detect evidence of an increased oxidant burden in blood after acute smoking in vivo, in either arterial or venous blood samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Protection of erdosteine on smoke-induced peripheral neutrophil dysfunction both in healthy and in bronchitic smokers

The purpose of the present study was to determine whether erdosteine and its metabolites (substances containing thiol groups) can prevent the alteration of the chemotactic function of polymorphonuclear cells (PMN) from peripheral blood induced by cigarette smoke of eight healthy non-smoking volunteers, when incubated in vitro before smoke exposure, and whether oral treatment with erdosteine (900 mg/day) for two weeks might restore the chemotaxis of PMN, either from eight healthy or from 16 chronic bronchitic smokers. The chemotactic stimuli in vitro were casein, lipopolysaccharides (LPS), and formyl-methionyl-leucyl-phenyalanine (FMLP). The results of the study in vitro have confirmed that PMN from non-smoking volunteers shows a reduced chemotactic responsiveness when exposed in vitro to smoke. This can be partially prevented in a dose-related manner by pre-incubation with erdosteine, its metabolites, cysteine, and glutathione (metabolites I and II being at least 10 times more active than the intact substance and the known biological standards also containing thiol groups). The experiment on PMN from healthy smokers (in a double-blind crossover design versus placebo) has indicated that the chemotaxis can be improved only after treatment with erdosteine. The same observation has been made in the experiment on PMN from smokers affected by chronic bronchitis (in a double-blind design versus placebo with two distinct groups). In these patients the phagocytic and bactericidal activities of PMN were not affected by the smoke and therefore, neither one was influenced by erdosteine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cigarette smoking on the transition dynamics in experimental gingivitis

This paper reports the findings of an experimental gingivitis study conducted in smokers and non-smokers. 33 volunteers were examined and underwent prophylaxis during a period of 4 weeks. 28 subjects who showed a plaque index less than 0.20 on all prophylaxis occasions were permitted to continue in the study. Subjects then had their gingival status recorded, had their teeth polished and were requested to abstain from all oral hygiene measures for the following 21 days. After 5 days, 10 days and 21 days, plaque and gingival status were recorded using the criteria of the plaque index and gingival index. After the examination on day 21, the teeth were polished and oral hygiene was re-instituted. Following 2 weeks of supervised oral hygiene, recordings of plaque and gingival status were performed. At the initial examination, there was no difference between the clinical assessment of plaque and gingival status in smokers and non-smokers. Similar amounts of plaque accumulated in the 2 groups during the period of no oral hygiene, but smokers exhibited less gingival inflammation assessed clinically than non-smokers. This difference occurred as a result of an apparently lowered incidence rate and a markedly higher recovery rate in smokers compared to non-smokers. These findings may indicate that smokers for reasons yet unknown have a reduced capacity to mount and maintain an effective defense reaction to a given plaque challenge.

Effects of mainstream and environmental tobacco smoke on the immune system in animals and humans: a review

This review evaluates the available information on the effects of mainstream and environmental tobacco smoke on the immune system in animals and humans. The primary emphasis is on mainstream smoke since little information is available on the effects of environmental smoke. The effects of mainstream tobacco smoke on the immune system in humans and animals are similar. Animals exposed to mainstream tobacco smoke for periods of a few weeks generally exhibit a slight immunostimulation. However, subchronic and chronic exposure studies indicate that immunosuppressive changes develop. Lymphocyte proliferation in response to the mitogens PHA and LPS is decreased, suggesting compromise of cell function. Antibody production can be suppressed. Smoke-exposed animals that are challenged with metastasizing tumors or viruses have been shown to exhibit a higher incidence of tumorigenic and infectious diseases, respectively. Localized immunological changes in the lung can include reduction of bronchus-associated lymphoid tissue and immunoglobulin levels. Smoking-related changes in the peripheral immune system of humans have included elevated WBC counts, increased cytotoxic/suppressor and decreased inducer/helper T-cell numbers, slightly suppressed T-lymphocyte activity, significantly decreased natural killer cell activity, lowered circulating immunoglobin titers, except for IgE which is elevated, and increased susceptibility to infection. The effects of environmental tobacco smoke on the immune system, in contrast to mainstream tobacco smoke, have just begun to be investigated and information available in the literature, to date, is limited. Immunoreactive substances are known to be present in environmental tobacco smoke, but to date, environmental tobacco smoke has been more closely associated with irritation than sensitization. A few studies have indicated a potential for environmental smoke-induced hypersensitivity and suppression of immunoregulatory substances. In contrast, other investigators have failed to detect immunological or other biological changes associated with environmental smoke. Clearly, more research is needed to resolve these differences.

Characterization of noncholinergic nicotine receptors on human granulocytes

The noncholinergic nicotine receptor on leukocytes identified earlier [Davies et al., Molec. Cell. Biochem. 44, 23 (1982)] was further characterized. Structure-activity relationships showed that a pyrrolidine ring containing a basic N atom is an important structural feature for ligands that bind to the receptor. Accordingly, the carcinogenic component of tobacco smoke, N-nitrosonornicotine, does not bind to the receptor. The stereoselectivity for the d-isomer, which was confirmed using [3H]d-nicotine as a ligand, together with the absolute configurational relationship between d-nicotine and L-proline, suggested that basic peptides containing proline as the N-terminal amino acid would bind to the receptor. The finding that Pro-Lys-Pro-Arg, which has been reported to inhibit granulocyte phagocytosis, bound to the receptor with an IC50 value of 3.5 microM is compatible with this idea. An increase in receptor binding, which was observed in the presence of plasma, could be ascribed to bicarbonate. The presence of bicarbonate in the binding assay, even when the pH of the buffer was carefully controlled, resulted in an increase (approximately 2-fold) in the apparent number of receptors without affecting the Kd value significantly. Increasing the pH of the buffer in the absence of bicarbonate also increased receptor binding, suggesting that bicarbonate may increase receptor binding by its known ability to increase intracellular pH at constant extracellular pH. Preincubation of cells with d-nicotine under certain conditions reduced the subsequent binding of [3H]d-nicotine to the receptor.

Altered chemotactic peptide binding in tobacco smokers' neutrophils

The functions of polymorphonuclear leukocytes from tobacco smokers are altered compared to those from nonsmokers. Since neutrophil chemotaxis and oxidative metabolism are mediated by surface receptors, we studied the association of the chemotactic peptide formyl Met-Leu-Phe with neutrophils from smokers and non-smokers. An apparently single class of binding sites was observed in neutrophils from all the non-smokers, whereas upwardly curving Scatchard plots were obtained for binding to smokers' cells. Thus changes at the receptor level may be responsible for the previously observed alterations in smoker neutrophil function.

Immune responsiveness of monkeys exposed chronically to cigarette smoke

Eleven adult male stumptailed monkeys (Macaca arctoides) were chronically exposed to either a low dose (human equivalent of 1 pack/day) or a high dose (human equivalent of 3 packs/day) of high-tar, high-nicotine University of Kentucky reference cigarette smoke for 4-8 years. Several parameters of their immunological response were compared to six nonsmoked control animals. The results from these experiments suggest that cigarette smoking does not significantly affect the response of spleen cells to the mitogens phytohemagglutinin or lipopolysaccharide. However, spleen cells from animals subjected to the heavy dose of cigarette smoke demonstrated a significant reduction in their natural killer cell-mediated lytic activity and a decreased response to concanavalin A. These results suggest that cigarette smoking may have a differential effect on lymphocyte subpopulations, and that the effects on the immune response are related to the dose of cigarette smoke.

Reversible alterations in immunoregulatory T cells in smoking. Analysis by monoclonal antibodies and flow cytometry

We characterized T-lymphocyte subsets in peripheral blood of smokers (N = 60) and nonsmokers (N = 35). Total T-lymphocytes and T cell subsets were similar to nonsmokers in light and moderate smokers. In heavy smokers, total OKT3+ cells were increased, the percentage of OKT4+ cells was decreased, and percentage and total number of OKT8+ cells were increased. The ratio of OKT4+ to OKT8+ lymphocytes was decreased in heavy smokers. The percentage of OKT8+ cells and the OKT4+/OKT8+ ratio returned to normal in heavy smokers six weeks after they stopped smoking. These findings suggest that cigarette smoking causes reversible alterations in immunoregulatory T cells.

Evidence for a noncholinergic nicotine receptor on human phagocytic leukocytes

A noncholinergic nicotine receptor on human phagocytic leukocytes has been characterized using the binding of 3H-(d,1)-nicotine. The average affinity +/- standard deviation of (d,1)-nicotine for the receptor on neutrophils is 36 +/- 18 nM (n = 6). The binding is saturable with an average of 8.7 x 10(4) sites per neutrophil. Monocytes and to a lesser extent lymphocytes but not erythrocytes also display specific binding. Bound nicotine is dissociable from the receptor and is not metabolized. Only close structural analogs of nicotine bind to the receptor, which is stereoselective for the (d)-isomer. The receptor can be occupied by (1)-nicotine at concentrations present in the blood of smokers. It is suggested that some of the adverse effects of smoking on leukocyte functions may be mediated by a specific nicotine receptor.

In vitro effect of tobacco smoke components on the functions of normal human polymorphonuclear leukocytes

The function of polymorphonuclear leukocytes (PMNs) has previously been shown to be impaired in smokers in comparison with healthy nonsmokers. Potent inhibition of PMN chemotaxis has been achieved with whole tobacco smoke, the gas phase of smoke, and a water-soluble extract of whole smoke. In the present work several aspects of PMN function were studied after exposure to water-soluble fraction of the particle phase of tobacco smoke collected on glass fiber filters. These tests included capillary tube random migration, chemotaxis under agarose, phagocytosis of yeasts, Nitro Blue Tetrazolium dye reduction, and whole-blood bactericidal activity. The water extract of the particle fraction of smoke had a high content of nicotine when compared with the levels achieved in plasma of smokers and a much lower concentration of aldehydes when compared with the gas phase of smoke. It had no cytotoxic effect and did not affect phagocytosis, oxygen consumption, or bactericidal activity. Nitro Blue Tetrazolium reduction of both resting and stimulated PMNs was significantly decreased only with the most concentrated solution. The tested solutions exerted a dose-related depressive effect on capillary tube random migration, whereas the random migration measured in the agarose chemotaxis test was normal. Nevertheless, the chemotactic response to a caseine solution was significantly decreased. The same tests were performed in the presence of several concentrations of a nicotine solution and the only test to be affected was the capillary tube random migration, and, that only at a very high concentration. The results of this study contribute to the more precise delineation of the extent of the dysfunction of PMNs exposed to tobacco smoke components and indicate that deleterious products are released from the particle phase of the smoke, which deposits all along the respiratory tree.

Effects of cigarette smoke and its constituents on the adherence of polymorphonuclear leukocytes

The in vitro effects of the water-soluble fraction of whole cigarette smoke (WSF) and two alpha, beta-unsaturated aldehydes of cigarette smoke (acrolein and crotonaldehyde) on polymorphonuclear leukocyte (PMNL) adherence were determined with nylon fiber columns. Each of these cigarette smoke constituents caused a dose-dependent inhibition of PMNL adherence. However, at least fivefold higher concentrations of these agents were necessary to inhibit adherence as compared with those necessary to achieve the same level of inhibition of PMNL chemotaxis. Furthermore, inhibition of adherence by WSF could be differentiated from its effects on chemotaxis in that reduced glutathione completely protected chemotaxis from the effects of WSF but only afforded partial protection to PMNL adherence. These data suggest that the inhibitory effects of WSF, acrolein, and crotonaldehyde on PMNL chemotaxis are not due to their inhibition of adherence. Finally, although PMNL adherence is considered to be an integral part of the chemotactic mechanism, differentiation between these two PMNL functions may be possible, since some inhibitors of chemotaxis do not have corresponding inhibitory effects on adherence.