Immune response in asymptomatic smokers

Altered effector function of peripheral cytotoxic cells in COPD

Background

There is mounting evidence that perforin and granzymes are important mediators in the lung destruction seen in COPD. We investigated the characteristics of the three main perforin and granzyme containing peripheral cells, namely CD8⁺ T lymphocytes, natural killer (NK; CD56⁺CD3^-) cells and NKT-like (CD56⁺CD3⁺) cells.

Methods

Peripheral blood mononuclear cells (PBMCs) were isolated and cell numbers and intracellular granzyme B and perforin were analysed by flow cytometry. Immunomagnetically selected CD8+ T lymphocytes, NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells were used in an LDH release assay to determine cytotoxicity and cytotoxic mechanisms were investigated by blocking perforin and granzyme B with relevant antibodies.

Results

The proportion of peripheral blood NKT-like (CD56⁺CD3⁺) cells in smokers with COPD (COPD subjects) was significantly lower (0.6%) than in healthy smokers (smokers) (2.8%, p < 0.001) and non-smoking healthy participants (HNS) (3.3%, p < 0.001). NK (CD56⁺CD3^-) cells from COPD subjects were significantly less cytotoxic than in smokers (16.8% vs 51.9% specific lysis, p < 0.001) as were NKT-like (CD56⁺CD3⁺) cells (16.7% vs 52.4% specific lysis, p < 0.001). Both cell types had lower proportions expressing both perforin and granzyme B. Blocking the action of perforin and granzyme B reduced the cytotoxic activity of NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells from smokers and HNS.

Conclusion

In this study, we show that the relative numbers of peripheral blood NK (CD56⁺CD3^-) and NKT-like (CD56⁺CD3⁺) cells in COPD subjects are reduced and that their cytotoxic effector function is defective.

Smoking and alcohol intervention before surgery: evidence for best practice

Smoking and hazardous drinking are common and important risk factors for an increased rate of complications after surgery. The underlying pathophysiological mechanisms include organic dysfunctions that can recover with abstinence. Abstinence starting 3-8 weeks before surgery will significantly reduce the incidence of several serious postoperative complications, such as wound and cardiopulmonary complications and infections. However, this intervention must be intensive to obtain sufficient effect on surgical complications. All patients presenting for surgery should be questioned regarding smoking and hazardous drinking, and interventions appropriate for the surgical setting applied.

A pilot study to examine the effects of smoking cessation on serum markers of inflammation in women at risk for cardiovascular disease

BACKGROUND

The links among smoking, inflammation, and cardiovascular disease (CVD) are well established. Several studies have demonstrated that quitting smoking reverses the risk of coronary heart disease within 5 to 10 years. However, the immediate effects of quitting smoking on inflammatory biomarkers associated with CVD risk have not been well described.

METHODS

In this pilot study, we examined a panel of circulating inflammatory biomarkers associated with CVD in "at-risk" women during the smoking cessation program. Forty-six women enrolled in a smoking cessation program consented to attend four study visits over 6 to 7 weeks. Health/medical information and blood were collected at each visit. Circulating levels of C-reactive protein (CRP), tumor necrosis factor (TNF), interleukin (IL)-6, soluble TNF receptor (sTNFR)-I, sTNFR-II, and soluble vascular cell adhesion molecule (sVCAM)-1 were measured, and changes between baseline levels (visit 1, while smoking) and visits 2 through 4 were determined.

RESULTS

Significant reductions in circulating levels of TNF, sTNFR-I, sTNFR-II, and sVCAM-1 were observed among participants over the course of the smoking cessation program. Serum levels of both IL-6 and CRP declined during the smoking cessation program; the changes were not statistically significant, however.

CONCLUSIONS

These findings suggest there are rapid consequences of smoking cessation on inflammatory biomarkers in women at risk for CVD. Additional, larger studies including diverse smokers desiring to quit are required to confirm changes in "measurable milestones" that could serve as motivating factors to assist smokers to quit.

The role of interleukin-1beta in murine cigarette smoke-induced emphysema and small airway remodeling

Interleukin-1beta (IL-1beta), a proinflammatory cytokine, is elevated in cigarette smokers. To determine whether IL-1beta plays a role in the pathogenesis of cigarette smoke-induced emphysema and small airway remodeling, IL-1 receptor knockout (IL1RKO), TNF-alpha receptor knockout (TNFRKO), or C57Bl/6 (control) mice were exposed to cigarette smoke acutely or for up to 6 months. With a single acute exposure, smoke elevated IL-1beta in C57Bl/6 mice. IL1RKO mice were protected against acute smoke-mediated increases in lavage inflammatory cells and matrix breakdown. In C57Bl/6 mice, acute smoke-mediated increases in inflammatory cells, serum IL-1beta, and serum TNF-alpha were blocked by z-VAD-fmk, a pan-caspase inhibitor, or z-WEHD-fmk, a caspase-1 (IL-1-converting enzyme, [ICE]) inhibitor. With 6 months of exposure, IL-1beta was no longer increased, but IL-18 was elevated. After 6 months of exposure, IL1RKO mice were 65% protected against emphysema, whereas TNFRKO mice were 83% protected. Both strains were completely protected against small airway remodeling. Lavage desmosine, hydroxyproline, and hyaluronan, matrix breakdown markers, were elevated in C57 but not IL1RKO mice. We conclude that IL-1beta plays a significant role in induction of murine emphysema and small airway remodeling, and is comparable to TNF-alpha in its effects. The protective effects of caspase inhibitors appear to be related to inhibition of ICE and raise the question of whether models that ameliorate emphysema with caspase inhibitors are really blocking IL-1beta (and IL-18) activation rather than blocking apoptosis.

Gram-positive and Gram-negative bacteria synergize with oxidants to release CXCL8 from innate immune cells

We have recently demonstrated that oxidants can activate monocytes via an action on Toll-like receptor (TLR) 2; however, it is unclear what functional consequence this has on immune surveillance for Gram-negative and -positive bacteria. Gram-negative and -positive bacteria and their related pathogen-associated molecular patterns (PAMPs) are sensed by TLR4 and TLR2, respectively. In the current study, we used a human monocyte cell line to show that oxidants prime cells to subsequent challenge with Gram-negative or -positive bacteria as well as PAMPs specific for TLR4 (LPS), TLR2/1 (Pam(3)CSK4), TLR2/6 (FSL-1), Nod1 (FK565), and Nod2 (MDP Lys 18). Similarly, activation of TLR4 with LPS primed for subsequent activation of cells by agonists of the TLR2/6 or TLR2/1 complex. However, no synergy was noted when cells were costimulated with Pam(3)CSK4 and FSL-1. We then tested blood (and isolated monocytes) derived from healthy smokers, which is oxidant primed, making it more sensitive to bacterial or PAMP stimulation when compared with blood of nonsmokers. Thus an oxidant stimulation, possibly via an action on TLR2 or associated transduction pathways, provides a signal that initiates inflammatory responses and sensitizes cells to pathogenic insults.

Problems and promise of immunological factors as biomarkers for schizophrenia

The complex and multifactorial etiology of psychiatric disorders, and in particular that of schizophrenia, has made it difficult to identify biomarkers suitable for clinical diagnosis. In schizophrenia research, the investigation of immune-related factors has been of central importance in the quest to unravel the disease etiology. However, immunological findings have been controversial, and the importance of an underlying immunopathology in schizophrenia remains to be irrevocably established. Here we review those findings that have been most consistently reported. We further address their potential utility for clinical diagnosis and drug development. We also discuss problems connected to sample collection and preparation, with special focus on their effects on immune-derived parameters. In light of recent findings, we highlight the potential of combining functional cell-based assays with high-throughput multiomics experiments for the discovery of novel biomarkers.

Functional Variants in Cell Death Pathway Genes and Risk of Pancreatic Cancer

Purpose: Fas-Fas ligand (FasL)–mediated death pathway is important in the life and death of immune cells and, therefore, influences immune surveillance of carcinogenesis. This study examined the association between functional variants of Fas (−1377G→A and −670A→G), FasL (−844T→C), and caspase-8 (CASP8) six-nucleotide deletion polymorphism (−652 6N ins→del) and risk of pancreatic cancer.

Experimental Design: Genotypes were determined in 397 cases with pancreatic cancer and 907 controls. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated by logistic regression, and all statistical tests were two sided.

Results: We found a significant decrease in risk of pancreatic cancer associated with FasL and CASP8 but not Fas polymorphisms. Compared with noncarriers, the ORs of developing pancreatic cancer for FasL −844CT and TT carriers were 0.73 (95% CI, 0.57-0.94) and 0.35 (95% CI, 0.19-0.63), and for CASP8 −652 6N ins/del and del/del carriers were 0.65 (95% CI, 0.50-0.85) and 0.56 (95% CI, 0.33-0.98), respectively. Gene-gene interaction between the FasL and CASP8 variants further reduced the cancer risk in a multiplicative manner (OR for the presence of both FasL −844TT and CASP8 −652 6N del/del genotype, 0.10; 95% CI, 0.01-0.75). On the other hand, a multiplicative joint effect between the FasL −844CC or CASP8 −652 6N ins/ins genotype and smoking or diabetes mellitus in intensifying risk of pancreatic cancer was also evident.

Conclusions: These results suggest that genetic variations in the death pathway genes FasL and CASP8 are involved in susceptibility to developing pancreatic cancer.

Killer cells in chronic obstructive pulmonary disease

COPD (chronic obstructive pulmonary disease) is a treatable and preventable disease state, characterized by progressive airflow limitation that is not fully reversible. It is a current and growing cause of mortality and morbidity worldwide, with the WHO (World Health Organization) projecting that total deaths attributed to COPD will increase by more than 30% in the next 10 years. The pathological hallmarks of COPD are destruction of the lung parenchyma (pulmonary emphysema), inflammation of the central airways (chronic bronchitis) and inflammation of the peripheral airways (respiratory bronchiolitis). The destructive changes and tissue remodelling observed in COPD are a result of complex interactions between cells of the innate and adaptive immune systems. The focus of the present review is directed towards the role of CD8(+) T-lymphocytes, NK (natural killer) cells and NKT cells (NK T-cells). These three classes of killer cell could all play an important part in the pathogenesis of COPD. The observed damage to the pulmonary tissue could be caused in three ways: (i) direct cytotoxic effect against the lung epithelium mediated by the activities of perforin and granzymes, (ii) FasL (Fas ligand)-induced apoptosis and/or (iii) cytokine and chemokine release. The present review considers the role of these killer cells in COPD.

Tobacco smoking inhibits expression of proinflammatory cytokines and activation of IL-1R-associated kinase, p38, and NF-kappaB in alveolar macrophages stimulated with TLR2 and TLR4 agonists

Tobacco smoking has been associated with impaired pulmonary functions and increased incidence of infections; however, mechanisms that underlie these phenomena are poorly understood. In this study, we examined whether smokers' alveolar macrophages (AM) exhibit impaired sensing of bacterial components via TLR2 and TLR4 and determined the effect of smoking on expression levels of TLR2, TLR4 and coreceptors, and activation of signaling intermediates. Smokers' AMs exhibited reduced gene expression and secretion of proinflammatory cytokines (TNF-alpha, IL-1beta, IL-6) and chemokines (RANTES and IL-8) upon stimulation with TLR2 and TLR4 agonists, S-[2,3-bis(palmitoyloxy)-(2-RS)-propyl]-N-palmitoyl-(R)-Cys-(S)-Ser-Lys4-OH trihydrochloride (Pam(3)Cys), and LPS, whereas expression of anti-inflammatory cytokines (IL-10 and IL-1 receptor antagonist) was not affected. TLR3 activation with polyinosinic-polycytidylic acid led to comparable or even higher cytokine responses in smokers' AMs, indicating that smoking-induced suppression does not affect all TLRs. Comparable expression of cytokines and chemokines was detected in PBMC and purified monocytes obtained from smokers and nonsmokers, demonstrating that the suppressive effect of smoking is restricted to the lung. TLR2/4-inducible IL-1R-associated kinase-1 (IRAK-1) and p38 phosphorylation and NF-kappaB activation was suppressed in smokers' AMs, whereas TLR2, TLR4, CD14, MD-2 mRNA levels, and TLR4 protein expression were not altered. These data suggest that changes in expression and/or activities of signaling intermediates at the postreceptor level account for smoking-induced immunosuppression. Thus, exposure of AMs to tobacco smoke induces a hyporesponsive state similar to endotoxin tolerance as manifested by inhibited TLR2/4-induced expression of proinflammatory cytokines, chemokines, and impaired activation of IRAK-1, p38, and NF-kappaB, resulting in suppressed expression of proinflammatory mediators.

Impairment of human NK cell cytotoxic activity and cytokine release by cigarette smoke

NK cells play essential roles in innate host defense against microbial infections and tumor surveillance. Although evidence suggests that smoking has adverse effects on the immune system, little is known about whether smoking compromises NK cell effector functions. In this study, we show that cigarette smoke-conditioned medium (SCM) dose-dependently inhibits in vitro IFN-gamma production by polyinosinic:polycytidylic acid (poly I:C)-activated PBMC and NK cells isolated from nonsmoking individuals. Similarly, SCM attenuated poly I:C-induced TNF-alpha production by PBMC and NK cells. The inhibitory effect of cigarette smoke on TNF-alpha production was reversible. PBMC and NK cells isolated from smokers displayed significant reduction of IFN-gamma and TNF-alpha secretions compared with nonsmokers in response to poly I:C activation. We further observed that SCM attenuated NK cell cytotoxic activity, which was associated with decreased up-regulation of perforin expression. Attenuated cytotoxic activity was also observed in PBMCs isolated from smokers. Finally, anti-IL-12 mAb-blocking data revealed that an attenuation of IFN-gamma production by PBMC was indirect, likely via attenuation of IL-12 production, and the effect on NK cells was IL-12-independent. Our data indicate that cigarette smoke compromises function of human NK cells. This may contribute to a higher incidence of viral infections and cancer among smokers.

Berberine suppresses inflammatory agents-induced interleukin-1beta and tumor necrosis factor-alpha productions via the inhibition of IkappaB degradation in human lung cells

Pulmonary inflammation is a characteristic of many lung diseases. Increased levels of pro-inflammatory cytokines, such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), have been correlated with lung inflammation. In this study, we demonstrated that various inflammatory agents, including lipopolysaccharide, 12-o-tetradecanoylphorbol-13-acetate, hydrogen peroxide, okadaic acid and ceramide, were able to induce IL-1beta and TNF-alpha productions in human lung epithelial cells (A-549), fibroblasts (HFL1), and lymphoma cells (U-937). Berberine, the protoberberine alkaloid widely distributed in the plant kingdom, was capable of suppressing inflammatory agents-induced cytokine production in lung cells. Inhibition of cytokine production by berberine was dose-dependent and cell type-independent. Moreover, the suppression of berberine on the cytokine production resulted from the inhibition of inhibitory kappaB-alpha phosphorylation and degradation. In conclusion, our findings suggested the potential role of berberine in the treatment of pulmonary inflammation.

Maternal tobacco smoking and decreased leukocytes, including dendritic cells, in neonates

Maternal smoking in pregnancy is associated with respiratory diseases in the offspring, possibly due to prenatal influences on the developing immune system. We investigated whether maternal smoking in pregnancy was associated with cord blood leukocyte numbers, including precursor dendritic cells, adjusting for concomitant factors. In a prospective healthy birth cohort study, total leukocyte counts were reduced in neonates of smoking mothers [10.7 (8.4-13.0), n=14] compared with nonexposed infants [14.7 (13.7-15.7), n=74, p=0.002] [geometric mean cells x 10(3)/microL (95% confidence interval)]. All leukocyte subsets were decreased, most prominently segmented neutrophils [4.3 (2.8-5.7) versus 6.2 (5.5-6.8), p=0.021], lymphocytes [3.8 (2.9-4.8) versus 5.0 (4.5-5.6), p=0.036], and myeloid precursor dendritic cells [12.7 cells/microL (9.1-17.8) versus 18.3 (15.8-21.2), p=0.055]. These differences persisted after adjustment for possible confounders. Predictors of myeloid precursor dendritic cell numbers in multivariable models were maternal smoking (-5.1 cells/microL, p=0.042), age (-0.5 cells/microL/y, p=0.035), and, marginally, asthma (+8.1 cells/microL, p=0.075). The decrease of all leukocytes in neonates of smoking mothers could be clinically significant and suggests a decreased cell production, increased peripheral recruitment, or retention in bone marrow. Given the importance of dendritic cells in early immune responses, their decrease might reflect an impact of maternal smoking on the developing fetal immune system.

Markers to measure immunomodulation in human nutrition intervention studies

Normal functioning of the immune system is crucial to the health of man, and diet is one of the major exogenous factors modulating individual immunocompetence. Recently, nutrition research has focused on the role of foods or specific food components in enhancing immune system responsiveness to challenges and thereby improving health and reducing disease risks. Assessing diet-induced changes of immune function, however, requires a thorough methodological approach targeting a large spectrum of immune system parameters. Currently, no single marker is available to predict the outcome of a dietary intervention on the resistance to infection or to other immune system-related diseases. The present review summarises the immune function assays commonly used as markers in human intervention studies and evaluates their biological relevance (e.g. known correlation with clinically relevant endpoints), sensitivity (e.g. within- and between-subject variation), and practical feasibility. Based on these criteria markers were classified into three categories with high, medium or low suitability. Vaccine-specific serum antibody production, delayed-type hypersensitivity response, vaccine-specific or total secretory IgA in saliva and the response to attenuated pathogens, were classified as markers with high suitability. Markers with medium suitability include natural killer cell cytotoxicity, oxidative burst of phagocytes, lymphocyte proliferation and the cytokine pattern produced by activated immune cells. Since no single marker allows conclusions to be drawn about the modulation of the whole immune system, except for the clinical outcome of infection itself, combining markers with high and medium suitability is currently the best approach to measure immunomodulation in human nutrition intervention studies. It would be valuable to include several immune markers in addition to clinical outcome in future clinical trials in this area, as there is too little evidence that correlates markers with global health improvement.

Cigarette smoke impairs NK cell-dependent tumor immune surveillance

In this study, we investigated the impact of cigarette smoke on tumor immune surveillance and its consequences to lung tumor burden in a murine lung metastasis model. Cigarette smoke exposure significantly increased the numbers of lung metastases following B16-MO5 melanoma challenge. This effect was reversible; we observed significantly fewer tumor nodules following smoking cessation. Using RAG2(-/-) and RAG2(-/-)gamma(c)(-/-) mice, we provide strong evidence that increased tumor incidence was NK cell dependent. Furthermore, we show that cigarette smoke suppressed NK activation and attenuated NK CTL activity, without apparent effect on activating or inhibitory receptor expression. Finally, activation of NK cells through bone marrow-derived dendritic cells conferred protection against lung metastases in smoke-exposed mice; however, protection was not as efficacious as in sham-exposed mice. To our knowledge, this is the first experimental evidence showing that cigarette smoke impairs NK cell-dependent tumor immune surveillance and that altered immunity is associated with increased tumor burden. Our findings suggest that altered innate immunity may contribute to the increased risk of cancer in smokers.

Disruption in Th1/Th2 immune response in young adult smokers

Interferon (IFN)-gamma and IL-10 cytokines, measures of Th1 and Th2 immunity, were examined in 20 healthy nonsmokers (12 males, 8 females) and 19 smokers (11 males, 8 females), aged 19-41 years (23.46+/-0.82 years). Nonsmokers came to the laboratory once; smokers came to the laboratory after ad lib smoking and following 24-h smoking abstinence. Salivary cotinine and expired CO confirmed smoking status. Plasma was collected at the end of each lab session and assayed for peripheral IFN-gamma and IL-10 levels. Among smokers, peripheral IFN-gamma, IL-10, or IFN-gamma/IL-10 ratio levels did not change in response to 24-h smoking abstinence. IFN-gamma levels and IFN-gamma/IL-10 ratios were higher among female smokers while smoking and following 24-h abstinence compared to male smokers in both conditions and compared to male and female nonsmokers. There was no sex or smoking status difference in IL-10 levels. Results suggest that cigarette smoking may have at least short-term damaging effects on the body's normal immune balance, particularly for women.

The effect of tobacco consumption and body mass index on complications and hospital stay after inguinal hernia surgery

BACKGROUND

The extent to which lifestyle factors such as tobacco consumption and obesity affect the outcome after inguinal hernia surgery has been poorly studied. This study was undertaken to assess the effect of smoking, smokeless tobacco consumption and obesity on postoperative complications after inguinal hernia surgery. The second aim was to evaluate the effect of tobacco consumption and obesity on the length of hospital stay.

METHODS

A cohort of 12,697 Swedish construction workers with prospectively collected exposure data on tobacco consumption and body mass index (BMI) from 1968 onward were linked to the Swedish inpatient register. Information on inguinal hernia procedures was collected from the inpatient register. Any postoperative complication occurring within 30 days was registered. In addition to this, the length of hospitalization was calculated. The risk of postoperative complications due to tobacco exposure and BMI was estimated using a multiple logistic regression model and the length of hospital stay was estimated in a multiple linear regression model.

RESULTS

After adjusting for the other covariates in the multivariate analysis, current smokers had a 34% (OR 1.34, 95% CI 1.04, 1.72) increased risk of postoperative complications compared to never smokers. Use of "Swedish oral moist snuff" (snus) and pack-years of tobacco smoking were not found to be significantly associated with an increased risk of postoperative complications. BMI was found to be significantly associated with an increased risk of postoperative complications (P = 0.04). This effect was mediated by the underweighted group (OR 2.94; 95% CI 1.15, 7.51). In a multivariable model, increased BMI was also found to be significantly associated with an increased mean length of hospital stay (P < 0.001). There was no statistically significant association between smoking or using snus, and the mean length of hospitalization after adjusting for the other covariates in the model.

CONCLUSION

Smoking increases the risk of postoperative complications even in minor surgery such as inguinal hernia procedures. Obesity increases hospitalization after inguinal hernia surgery. The Swedish version of oral moist tobacco, snus, does not seem to affect the complication rate after hernia surgery at all.

Heavy smoking and liver

Smoking causes a variety of adverse effects on organs that have no direct contact with the smoke itself such as the liver. It induces three major adverse effects on the liver: direct or indirect toxic effects, immunological effects and oncogenic effects. Smoking yields chemical substances with cytotoxic potential which increase necro-inflammation and fibrosis. In addition, smoking increases the production of pro-inflammatory cytokines (IL-1, IL-6 and TNF- alpha) that would be involved in liver cell injury. It contributes to the development of secondary polycythemia and in turn to increased red cell mass and turnover which might be a contributing factor to secondary iron overload disease promoting oxidative stress of hepatocytes. Increased red cell mass and turnover are associated with increased purine catabolism which promotes excessive production of uric acid. Smoking affects both cell-mediated and humoral immune responses by blocking lymphocyte proliferation and inducing apoptosis of lymphocytes. Smoking also increases serum and hepatic iron which induce oxidative stress and lipid peroxidation that lead to activation of stellate cells and development of fibrosis. Smoking yields chemicals with oncogenic potential that increase the risk of hepatocellular carcinoma (HCC) in patients with viral hepatitis and are independent of viral infection as well. Tobacco smoking has been associated with suppression of p53 (tumour suppressor gene). In addition, smoking causes suppression of T-cell responses and is associated with decreased surveillance for tumour cells. Moreover, it has been reported that heavy smoking affects the sustained virological response to interferon (IFN) therapy in hepatitis C patients which can be improved by repeated phlebotomy. Smoker's syndrome is a clinico-pathological condition where patients complain of episodes of facial flushing, warmth of the palms and soles of feet, throbbing headache, fullness in the head, dizziness, lethargy, prickling sensation, pruritus and arthralgia.

Risk reduction: Perioperative smoking intervention

Smoking is a well-known risk factor for perioperative complications. Smokers experience an increased incidence of respiratory complications during anaesthesia and an increased risk of postoperative cardiopulmonary complications, infections and impaired wound healing. Smokers have a greater risk of postoperative intensive care admission. Even passive smoking is associated with increased risk at operation. Preoperative smoking intervention 6-8 weeks before surgery can reduce the complications risk significantly. Four weeks of abstinence from smoking seems to improve wound healing. An intensive, individual approach to smoking intervention results in a significantly better postoperative outcome. Future research should focus upon the effect of a shorter period of preoperative smoking cessation. All smokers admitted for surgery should be informed of the increased risk, recommended preoperative smoking cessation, and offered a smoking intervention programme whenever possible.

Inflammatory markers and loss of muscle mass (sarcopenia) and strength

PURPOSE

The objective of this study was to investigate whether high levels of serum interleukin (IL)-6, C-reactive protein (CRP), and alpha1-antichymotrypsin (ACT) were associated with the loss of muscle strength or muscle mass (sarcopenia) in older persons.

SUBJECTS

The study included 986 men and women of the Longitudinal Aging Study Amsterdam, with a mean age of 74.6 years (standard deviation 6.2).

METHODS

Grip strength (n = 986) and appendicular muscle mass (n = 328, using dual-energy x-ray absorptiometry) were obtained in 1995 and 1996 and repeated after a 3-year follow-up. Loss of muscle strength was defined as a loss of grip strength greater than 40%, and sarcopenia was defined as a loss of muscle mass greater than 3%, approximating the lowest 15% of the study sample.

RESULTS

Multiple linear and logistic regression analyses revealed that higher levels of IL-6 were associated with greater decline in muscle strength, which decreased by -3.21 kg (standard error 0.81) per standard deviation increase in log-transformed IL-6. After adjustment for confounders, including sociodemographic, health, and lifestyle factors, high IL-6 (>5 pg/mL) and high CRP (>6.1 mug/mL) were associated with a 2 to 3-fold greater risk of losing greater than 40% of muscle strength. Persons with high levels of ACT (>181% of the normal human pooled plasma) were 40% less likely to experience loss of muscle strength and tended (P = .07) to have a smaller decline in muscle mass compared with those in the lowest quartile of ACT. No consistent associations of IL-6 and CRP with sarcopenia were found.

CONCLUSION

The findings of this prospective, population-based study suggest that higher levels of IL-6 and CRP increase the risk of muscle strength loss, whereas higher levels of ACT decrease the risk of muscle strength loss in older men and women.

Prenatal, perinatal, and heritable influences on cord blood immune responses

BACKGROUND

Maternal and perinatal environmental exposures, as well as inherited factors, may influence neonatal immune responses.

OBJECTIVE

To determine relations of maternal and perinatal exposures to antigen-specific cord blood lymphoproliferative responses.

METHODS

In 427 newborns from a Boston pregnancy/birth cohort, lymphoproliferative responses in cord blood mononuclear cells to stimulation with cockroach (Bla g 2), house dust mite (Der f 1), ovalbumin, and mitogen phytohemagglutinin were measured as stimulation index (SI). We used the Wilcoxon rank sum and chi2 tests to evaluate predictors of ovalbumin SI as a continuous ranked or dichotomous outcome. We used t test and Spearman correlation for univariate testing and linear regression to evaluate predictors of natural log-transformed Bla g 2, Der f 1, and phytohemagglutinin SI. Logistic multivariate regression was applied to evaluate predictors of Bla g 2, Der f 1, and phytohemagglutinin SI dichotomized at 2 or at the median for phytohemagglutinin.

RESULTS

Maternal smoking during pregnancy, inadequate or excessive maternal weight gain during pregnancy, neonate black race/ethnicity (compared with white), and Apgar score less than 8 were each independently associated with increased cord blood mononuclear cell proliferative responses to stimulation with Bla g 2 and/or Der f 1. Maternal history of asthma was associated only with increased lymphoproliferative response to ovalbumin stimulation.

CONCLUSIONS

Distinct fetal and perinatal exposures and black race/ethnicity may be associated with increased cord blood lymphoproliferative responses. The implications of these findings for future development of allergy or asthma are, as yet, unknown.

Increased natural killer cell activity in patients with an abdominal aortic aneurysm

BACKGROUND

Natural killer (NK) cells have an emerging role in the development of chronic disease and in the direction and maintenance of inflammatory responses. Abdominal aortic aneurysms (AAA) is a chronic inflammatory disorder of unknown aetiology. The aim was to investigate whether NK cells showed altered function in patients with an AAA.

METHODS

The presence, phenotype and function of peripheral blood and tissue NK cells from patients with an AAA, peripheral vascular disease (PVD) and healthy age-sex-matched controls were assessed before and after surgery.

RESULTS

Patients with an AAA had significantly higher (P < 0.010) percentages of peripheral blood NK cells (mean (95 per cent c.i.) 23.8 (2.6) per cent) than patients with PVD (17.4 (2.9) per cent) and control subjects (16.2 (2.8) per cent). The NK cells from patients with an AAA had increased cytotoxicity on a per cell basis towards both an NK-sensitive target cell line and human aortic smooth muscle cells. Increased NK cell proportions (22.7 (3.5) per cent) and cytotoxic activity, together with higher C-reactive protein values, persisted after successful AAA repair.

CONCLUSION

These data support the hypothesis that increased NK cytotoxicity could be a contributing factor in the generation or potentiation of inflammation in patients with an AAA.

Effect of maternal smoking on breast milk interleukin-1alpha, beta-endorphin, and leptin concentrations and leptin concentrations

Tobacco smoke is immunotoxic, but the effect of smoking on the immunologic function of the mammary gland of mothers who smoke cigarettes ("smoker mothers") has not been studied. Our objective was to test, in smoker mothers, the colostral and transitional milk concentrations of interleukin-(IL)1alpha. The immunomodulators beta-endorphin and leptin were also tested. Pregnant women who self-identified as smokers (greater than or equal to 5 cigarettes per day through pregnancy) or nonsmokers were recruited for study participation. The study population included 42 smoker and 40 nonsmoker nursing mothers, with otherwise uncomplicated gestation, delivery, and puerperium, who were breast-feeding ad libitum their healthy neonates. Colostrum was obtained on the third postpartum day at 0900 hr and transitional milk on the 10th postpartum day at 0900 hr. IL-1alpha concentrations were significantly reduced in the colostrum of smoker mothers compared with nonsmoker mothers (p < 0.01). Colostral beta-endorphin and leptin concentrations were comparable. No significant differences were found between smoker and nonsmoker lactating mothers in transitional milk concentrations of IL-1alpha, beta-endorphin, and leptin. Moreover, beta-endorphin and leptin concentrations were significantly reduced in transitional milk samples compared with colostrum of both smoker and nonsmoker mothers (p < 0.05); also, IL-1alpha transitional milk concentrations were reduced compared with colostrum, but without any significance. This analysis shows that maternal smoking alters the colostral milk levels of the proinflammatory cytokine IL-1alpha. The altered postnatal provision of alternative source of the proinflammatory cytokine IL-1alpha adds understanding to how breast-feeding could be nonprotective against infections among the neonates nursed by smoker mothers.

Mediators of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a major and increasing global health problem that is now a leading cause of death. COPD is associated with a chronic inflammatory response, predominantly in small airways and lung parenchyma, which is characterized by increased numbers of macrophages, neutrophils, and T lymphocytes. The inflammatory mediators involved in COPD have not been clearly defined, in contrast to asthma, but it is now apparent that many lipid mediators, inflammatory peptides, reactive oxygen and nitrogen species, chemokines, cytokines, and growth factors are involved in orchestrating the complex inflammatory process that results in small airway fibrosis and alveolar destruction. Many proteases are also involved in the inflammatory process and are responsible for the destruction of elastin fibers in the lung parenchyma, which is the hallmark of emphysema. The identification of inflammatory mediators and understanding their interactions is important for the development of anti-inflammatory treatments for this important disease.

Etiology and pathogenesis of periodontal diseases

The two most prevalent and most investigated periodontal diseases are dental plaque-induced gingivitis and chronic periodontitis. The last 10 to 15 years have seen the emergence of several important new findings and concepts regarding the etiopathogenesis of periodontal diseases. These findings include the recognition of dental bacterial plaque as a biofilm, identification and characterization of genetic defects that predispose individuals to periodontitis, host-defense mechanisms implicated in periodontal tissue destruction, and the interaction of risk factors with host defenses and bacterial plaque. This article reviews current aspects of the etiology and pathogenesis of periodontal diseases.

Inhibition of human neutrophil reactive oxygen species production and p67phox translocation by cigarette smoke extract

The association between cigarette smoking and atherogenesis is well established. Inflammatory cells may participate in atherogenesis via activation of the NADPH oxidase and the subsequent production of reactive oxygen species (ROS), which exacerbates endothelial injury. However, little is known about the ability of cigarette smoke (CS) to modulate NADPH oxidase protein function. In this study, we investigated the ability of a CS extract derived from a high tar cigarette to alter human neutrophil ROS production and the translocation of two NADPH oxidase proteins, p47phox and p67phox. Phorbol ester-induced intracellular and extracellular production of ROS was reduced following CS treatment as measured by enhanced luminol or isoluminol chemiluminescence, respectively, (luminol AUC was reduced by 59%, p < or =0.0001; isoluminol by 49%, p < or =0.001). The phorbol ester-induced phosphorylation and translocation of p47phox from the cytosol to the membrane was not changed by CS treatment but the translocation of p67phox was reduced. Cigarette smoke treatment alone did not provoke neutrophil ROS production. These findings demonstrate that CS treatment reduced agonist-induced human neutrophil ROS production independent of p47phox phosphorylation and translocation from the cytosol to the membrane. However, this inhibition could be attributed to a reduction in translocation of another cytosolic NADPH oxidase protein, p67phox. Although neutrophil-generated ROS have been implicated in the pathogenesis of atherosclerosis, this does not appear to be the mechanism by which CS induces vascular injury.

Interleukin-1beta causes pulmonary inflammation, emphysema, and airway remodeling in the adult murine lung

The production of the inflammatory cytokine interleukin (IL)-1 is increased in lungs of patients with chronic obstructive pulmonary disease (COPD) or asthma. To characterize the in vivo actions of IL-1 in the lung, transgenic mice were generated in which human IL-1beta was expressed in the lung epithelium with a doxycycline-inducible system controlled by the rat Clara cell secretory protein (CCSP) promoter. Induction of IL-1beta expression in the lungs of adult mice caused pulmonary inflammation characterized by neutrophil and macrophage infiltrates. IL-1beta caused distal airspace enlargement, consistent with emphysema. IL-1beta caused disruption of elastin fibers in alveolar septa and fibrosis in airway walls and in the pleura. IL-1beta increased the thickness of conducting airways, enhanced mucin production, and caused lymphocytic aggregates in the airways. Decreased immunostaining for the winged helix transcription factor FOXA2 was associated with goblet cell hyperplasia in IL-1beta-expressing mice. The production of the neutrophil attractant CXC chemokines KC (CXCL1) and MIP-2 (CXCL2), and of matrix metalloproteases MMP-9 and MMP-12, was increased by IL-1beta. Chronic production of IL-1beta in respiratory epithelial cells of adult mice causes lung inflammation, enlargement of distal airspaces, mucus metaplasia, and airway fibrosis in the adult mouse.

Accelerated enlargement of experimental abdominal aortic aneurysms in a mouse model of chronic cigarette smoke exposure

BACKGROUND

Cigarette smoking and pulmonary emphysema are strongly associated with abdominal aortic aneurysms (AAAs), but the biologic mechanisms linking these conditions are undefined.

STUDY DESIGN

To determine if exposure to cigarette smoke influences formation and growth of experimental AAAs, 129/SvEv mice were acclimated to daily cigarette smoke exposure for 2 weeks followed by transient elastase perfusion of the abdominal aorta to induce aneurysmal degeneration. Smoking was continued for intervals of either 2 or 12 weeks (8 mice per group). Nonsmoking 129/SvEv controls (n = 29) underwent elastase perfusion and followup evaluation at the same time intervals. In all animals, abdominal aortic diameter (AD) was measured to determine interval increases in AD (Delta AD), with AAAs defined as a Delta AD > 100%.

RESULTS

Preperfusion and immediate postperfusion ADs were not significantly different between experimental groups. Aneurysmal dilatation was present 2 weeks after elastase perfusion in both smoking mice and nonsmoking controls, with no significant difference in final AD (mean +/- SEM: smoking, 1.23 +/- 0.11 mm versus nonsmoking, 1.22 +/- 0.05 mm). There were also no differences in the overall extent of aortic dilatation (Delta AD smoking, 136 +/- 24% versus nonsmoking, 138 +/- 10%), or the incidence of AAAs (smoking, 75% versus nonsmoking, 79%). Although all animals had developed AAAs by 12 weeks after elastase perfusion, the overall extent of aortic dilatation was 50% greater in smoking mice compared with nonsmoking controls (Delta AD smoking, 204 +/- 23% versus nonsmoking, 135 +/- 17%; p < 0.05).

CONCLUSIONS

Short-term exposure to cigarette smoke did not alter initial development of experimental AAAs, but chronic smoke exposure was associated with a substantial increase in the late progression of aneurysmal dilatation. This novel combination of in vivo experimental models offers a new approach to investigate mechanisms by which cigarette smoking promotes aneurysmal degeneration.

Particulate phase cigarette smoke increases MnSOD, NQO1, and CINC-1 in rat lungs

Loss of antioxidant/oxidant homeostasis perpetuates inflammation in the lungs and may contribute to the development of COPD and lung cancer. Cigarette smoke (CS) is a primary source of airway oxidative stress and recruits inflammatory cells into smokers' lungs. However, whether these consequences are attributable to a specific or the collective fraction of CS is unknown. We investigated whether the particulate or the gas phase of CS would alter expression of the antioxidant enzymes MnSOD and NQO1 or CINC-1. Sprague Dawley rats were exposed to sham (n = 10) or the particulate phase (PP; n = 10) or gas phase (n = 10) of a Kentucky reference cigarette (1R4F) for 2 h/d for 28 d, after which animals were sacrificed and the lower left lobe of the lung was removed. Immunoblots for SOD and NQO1 revealed that lungs exposed to PP had higher MnSOD/actin and NQO1/actin ratios than either sham-or gas phase-treated animals. In contrast, CuZnSOD remained unchanged. In PP-exposed animals, CINC-1 was 3-fold higher than in sham-exposed animals. The increases in MnSOD and NQO1 protein were associated with increases in total SOD, NQO1, and MPO activities. These data provide evidence that the PP of CS alters oxidant/antioxidant homeostasis in the lungs and participates in the pathogenesis of CS-induced lung diseases such as COPD and cancer.

Effect of smoking and abstention on oxidative burst and reactivity of neutrophils and monocytes

BACKGROUND

Smoking is associated with surgical wound infections, impaired wound healing, and tissue-destructive disorders. The mechanisms are largely unknown, but changes in the function and activity of inflammatory cells may be involved.

METHODS

Seventy healthy volunteers (54 smokers and 16 never smokers) were included. The smokers were studied while they smoked and after 20 days of abstinence. After the first 10 days of abstinence, they were randomized to double-blind treatment with transdermal nicotine patch 25 mg per day or placebo. Venous blood neutrophils and monocytes were sampled and isolated. In 22 randomly selected smokers and in all never smokers, the oxidative burst and chemotaxis were determined by a chemiluminescence response assay and a modified Boyden chamber technique, respectively. Stimulants were opsonized zymosan, formyl-Met-Leu-Phe, and zymosan-activated serum.

RESULTS

The neutrophil and monocyte oxidative burst was 50% and 68% lower, respectively, in smokers compared to never smokers (P < .05). Neutrophil chemotaxis was 93% higher in smokers (P < .05). Monocyte chemotaxis was lower in smokers compared to never smokers (P < .05). After 20 days of abstinence, neutrophil oxidative burst increased to the level of never smokers (P < .05); monocyte oxidative burst increased by 50% (P < .05). Chemotaxis was only marginally affected. The changes induced by abstinence were less pronounced in the transdermal nicotine patch group compared to the placebo group.

CONCLUSIONS

Smoking attenuates the oxidative burst of inflammatory cells and increases chemotaxis. Three weeks of abstinence normalize the oxidative burst, but affect chemotaxis only marginally.

Pulmonary and cardiovascular consequences of smoking

The extensive worldwide disease burden attributable to tobacco smoking is reviewed, with particular attention to the epidemiologic and clinical aspects, molecular and cellular mechanisms, and pathophysiology of a variety of smoking-related pulmonary diseases, and the epidemiology and clinical presentation of smoking-related atherosclerotic disease as it affects the cardiovascular system cerebral circulation, the aorta, and the peripheral arterial tree.

Enhanced glucocorticoid sensitivity of cytokine release from circulating leukocytes stimulated with lipopolysaccharide in healthy male smokers

Smoking is a strong cardiovascular risk factor that promotes inflammation. The source of elevated pro-inflammatory cytokines in the circulation of smokers is not fully understood. We investigated the release of pro-inflammatory cytokines from circulating leukocytes stimulated with lipopolysaccharide (LPS) and its inhibition by glucocorticoids in smokers and non-smokers. Ninety-three middle-aged apparently healthy men were categorized as smokers (> 10 cigarettes/day; n = 41) or life-long non-smokers (n = 52). Peripheral cortisol was assessed from overnight urine. C-reactive protein (CRP) and tumor necrosis factor (TNF)-alpha were measured in plasma. LPS-stimulated interleukin (IL)-6 and TNF-alpha release from harvested circulating leukocytes were assessed using an in vitro whole blood assay with and without co-incubation of increasing concentrations of either dexamethasone or hydrocortisone. Glucocorticoid sensitivity was defined as the concentration of glucocorticoids required that inhibits LPS-stimulated cytokine release by 50%. Smokers had higher CRP levels (p = .005) and a trend for higher basal TNF-alpha levels (p < .07), and they also showed lower IL-6 and TNF-alpha release after LPS-stimulation than non-smokers (p's < .001). While peripheral cortisol concentration showed no significant group difference, inhibition of LPS-stimulated leukocyte IL-6 and TNF-alpha release by either glucocorticoid was enhanced in smokers as compared to non-smokers (p's < .022). The finding suggests that, in spite of a low-grade systemic inflammation, smokers have decreased LPS-stimulated cytokine release from circulating leukocytes and greater glucocorticoid sensitivity of this cytokine release than non-smokers. Circulating leukocytes unlikely contribute to the elevated pro-inflammatory cytokine levels in the blood of smokers.

Impact of cigarette smoking on response to interferon therapy in chronic hepatitis C Egyptian patients

AIM: Smoking may affect adversely the response rate to interferon-α . Our objective was to verify this issue among chronic hepatitis C patients.

METHODS: Over the year 1998, 138 chronic hepatitis C male Egyptian patients presenting to Cairo Liver Center, were divided on the basis of smoking habit into: group I which comprised 38 smoker patients ( > 30 cigarettes/d) and group II which included 84 non-smoker patients. Irregular and mild smokers (16 patients) were excluded. Non eligible patients for interferon-α therapy were excluded from the study and comprised 3/38 (normal ALT) in group I and 22/84 in group II (normal ALT, advanced cirrhosis and thrombocytopenia). Group I was randomly allocated into 2 sub-groups: group Ia comprised 18 patients who were subjected to therapeutic phlebotomy while sub-group Ib consisted of 17 patients who had no phlebotomy. In sub-group Ia, 3 patients with normal ALT after repeated phlebotomies were excluded from the study. Interferon-α 2b 3 MU/TIW was given for 6 mo to 15 patients in group Ia, 17 patients in group Ib and 62 patients in group II. Biochemical, virological end-of- treatment and sustained responses were evaluated.

RESULTS: At the end of interferon-α treatment, ALT was normalized in 3/15 patients (20%) in group Ia and 2/17 patients (11.8%) in group Ib compared to17/62 patients (27.4%) in group II (P = 0.1). Whereas 2/15 patients (13.3%) in group Ia. and 2/17 patients (11.8%) in group Ib lost viraemia compared to 13/62 patients (26%) in group II (P = 0.3). Six months later, ALT was persistently normal in 2/15 patients (13.3%) in group 1a and 1/17 patients (5.9%) in group Ib compared to 9/62 patients (14.5%) in group II (P = 0.47). Viraemia was eliminated in 1/15 patients (6.7%) in group Ia and 1/17 patients (5.9%) in group Ib compared to 7/62 patients (11.3%) in group II, but the results did not mount to statistical significance (P = 0.4).

CONCLUSION: Smokers suffering from chronic hepatitis C tend to have a lower response rate to interferon-α compared to non-smokers. Therapeutic phlebotomy improves the response rate to interferon-α therapy among this group.

Immunomodulatory effects of mineral fibres in occupationally exposed workers

In the context of a large-scale molecular epidemiology study, the possible immunomodulatory effects of mineral fibres, in workers occupationally exposed to asbestos, rockwool and glass fibres, were examined. In each plant, 61, 98 and 80 exposed workers and 21, 43 or 36 control clerical subjects, respectively, were recruited. In the case of the asbestos-exposed subjects, an additional town-control group of 49 people was included. Evidence of pulmonary fibrosis was found in 42% of the asbestos-exposed workers, while evidence of pleural fibrosis was found in 24%. The asbestos-exposed cohort had significantly decreased forced vital capacity of lungs as well as forced expiratory volume per first second. Our findings indicate that exposure to all three types of fibres examined modulates to different degrees the immune response. Suppression of T-cell immunity and to a lesser extent, B-cell immunity was found in the case of workers from a former asbestos cement plant, while stimulation of T-cell response was observed in rockwool workers, and stimulation of T- and B-cell response was seen in glass fibre workers. Depression of the percentage of lymphocyte subpopulation of CD 16+56 (natural killer cells) in peripheral blood was found in glass fibre workers. Statistical analysis showed increased levels of proinflammatory cytokines (IL-6 asbestos; IL-8 all three fibres), expression of adhesion molecule L-selectin on granulocytes and monocytes (asbestos), levels of soluble adhesion molecules (SAMs) in sera (ICAM-1 all three fibres; E-selectin glass fibres), increased levels of immunoglobulin E (asbestos and rockwool) and elevated expression of activation markers on eosinophils (CD66b asbestos, glass fibres; CD69 asbestos). Significant correlations were observed between lymphocyte proliferation and markers of DNA damage and repair. Increased levels of proinflammatory cytokines, SAMs, immunoglobulin E and elevated expression of activation markers on eosinophils was found in people with symptoms of hypersensitivity and an elevated inflammatory status.

Exposition à la fumée du tabac et risque infectieux bactérien

INTRODUCTION

Tobacco smoke is a proven risk factor for bacterial infection.

STATE OF THE ART

In adults without COPD, smoking is associated with a significant increase in the relative risk (RR) of pneumonia (RR=2.97; 95% CI 1.52-5.81), S pneumoniae pneumonia (RR=2.50; 95% IC 1.50-5.10), Legionella infection (RR=3.75; 95% CI 2.17-6.17). Smoking has clearly been shown to be associated with an increased risk of tuberculosis (RR=2.60; 95% CI 2,20-3,20), and also with increased incidence of post-operative infections. In young children whose parents smoke, passive exposure to tobacco smoke is associated with an increased relative risk of seasonal infections (RR=1.7; CI 95% 1.55-1.91) and recurrent otitis media (RR=1.48; 95% CI 1.08-2.04). Passive smoking also increases risk of pneumonia in adults (RR=2.5; CI 95% 1.2-5.1). Plausible explanations of the increased risk of infection in active or passive smokers include increased bacterial adherence, decrease of lung and nasal clearance, and changes in the immune response.

CONCLUSIONS

Exposure to tobacco smoke approximately doubles the risk of infection. This increased burden of infection has significant healthcare cost implications. Each infectious episode in an individual should prompt an attempt at smoking cessation.

Dose-effect relation of smoking and the interleukin-1 gene polymorphism in periodontal disease

BACKGROUND

Periodontitis is a bacterial inflammatory disease leading to attachment loss with the consequence of tooth loss. There exists a multifactorial risk pattern including bacterial challenge, smoking, age, gender, diabetes, and socioeconomic and genetic factors. Smoking has the highest impact on the course of the disease modulated by all the other factors. Here, we report the relationship between smoking and the genetic polymorphism of interleukin-1 (IL-1).

METHODS

In a randomly selected population-based study, we genotyped 1,085 test persons for the IL-1 genotype, examined their periodontal status, and assessed their smoking behavior including present and past quality and quantity of smoking.

RESULTS

There was a significant dose-effect relationship between the exposure to tobacco smoke and the extent of periodontal disease assessed as attachment loss and tooth loss. Moreover, there was a gene-environmental interaction. Subjects bearing at least one copy of the variant allele 2 at positions IL-1A -889 and IL-1B +3954 (genotype positive) had an enhanced smoking-associated periodontitis risk as compared to their IL-1 genotype-negative counterparts. With genotype-negative non-smokers as a reference, logistic regression resulted in odds ratios of 0.98 (95% confidence interval: 0.83 to 1.14), 2.37 (1.96 to 2.87), and 4.50 (2.30 to 8.82) for genotype-positive non-smokers, genotype-negative smokers, and genotype-positive smokers, respectively.

CONCLUSIONS

There is a gene-environmental interaction between smoking and the IL-1 genetic polymorphism. Smokers bearing the genotype-positive IL-1 allele combination have an increased risk of periodontitis. The IL-1 genotype has no influence in non-smokers.

Impact of genetic polymorphisms on the smoking-related risk of periodontal disease: the population-based study SHIP

Periodontitis is a bacterial inflammatory disease leading to attachment loss with the consequence of tooth loss. There exists a multifactorial risk pattern including bacterial challenge, smoking, age, sex, diabetes, socio-economic and genetic factors. Smoking has the highest impact on the course of the disease modulated by all the other factors. Here, we report the relationship between smoking and the polymorphisms of genetic polymorphisms inflicted in the pathogenesis.

In a randomly selected population-based study, 1083 subjects were typed for the polymorphisms of the IL-1 genotype, Fcγ RIIIb receptor gene, myeloperoxidase and N-acetyltransferase (NAT2) and related to their periodontal state. Smoking behavior was assessed including present and past quality and quantity of smoking.

There is a significant dose-effect relationship between the exposure to tobacco smoke and the extent of periodontal disease assessed as attachment loss and tooth loss. Moreover, there are gene-environmental interactions as subjects bearing variant genotypes show an enhanced smoking-associated risk of the disease modulated by these genotypes. In non-smokers, the impact of these genetic polymorphisms is mostly negligible.

This study provides support for the hypothesis that subjects bearing genetic variants of polymorphically expressed phenotypes are at an increased risk of periodontitis when smoking. Mostly, this may be accomplished via the influence of smoking-related impairment on defense mechanisms rather than on the pathogenic pathways.

The interleukin-1 polymorphism, smoking, and the risk of periodontal disease in the population-based SHIP study

Several studies have shown a role for interleukin-1 gene cluster polymorphisms in the risk assessment for periodontal diseases. In the Study of Health in Pomerania (SHIP), 3148 subjects were randomly selected from the population and assessed for a broad range of diseases and environmental/behavioral risk factors. From the complete study group in the age 40 to 60 years, N = 1085 subjects were genotyped for the interleukin-1 genotype composite polymorphism in relation to periodontal parameters. The study objective was to elucidate the gene-environment interaction between the risk factors smoking and IL-1 polymorphism. An increased risk of periodontal disease was found for IL-1 genotype-positive smokers: odds ratio adjusted for age, sex, education, and plaque OR = 2.50 (95% C.I. 1.21 to 5.13; p = 0.013). This was not the case with subjects who never smoked: OR = 1.09 (0.73-1.62; p = 0.676). These results support the hypothesis of gene-environmental interaction in periodontitis.