Down-regulation of SARS-CoV-2 neutralizing antibodies in vaccinated smokers

Vaccination is an effective approach to help control coronavirus disease 2019 (COVID-19). However, since the vaccines produce a heterogenous immune response, the risk of breakthrough infection is increased in vaccinated individuals who generate low levels of neutralizing antibodies (NAbs). It is therefore paramount in the fight against COVID-19 to identify individuals who have a higher risk of breakthrough infection despite being vaccinated. Here we addressed the effect of cigarette smoking on the production of neutralizing antibodies (NAbs) following COVID-19 vaccination since smoking profoundly suppresses the adaptive immune response to pathogen infection and the association between vaccination and smoking remains unclear. The SARS-CoV-2 Spike antibodies and NAbs (days 0, 14, 42, and 90) were measured in 164 participants received two vaccine doses of an inactivated vaccine (Sinovac-CoronaVac) longitudinally. Anti-Spike antibodies was elevated 14 and 42 days after COVID-19 vaccination compared to baseline (i.e., “Day 0”). Notably, RBD antibodies showed significantly higher expression in the nonsmoking group (n=153) than the smoking (n=11) group on day 42 (p<0.0001, Student’s t-test). NAbs continually increased after the first and second vaccine dose, peaking on day 42. NAbs titers then significantly decreased until day 90. Compared to nonsmokers, the NAb levels in smokers remained low throughout the period of testing. The median NAb titers in the smoking group was 1.40-, 1.32-, or 3.00-fold lower than that of nonsmoking group on day 14, 42, or 90, respectively. Altogether, our results indicate that smoking is a specific risk factor for COVID-19 breakthrough infection following vaccination.

Prepared and Reactive Inhibition in Smokers and Non-smokers

Models of addiction have identified deficits in inhibitory control, or the ability to inhibit inappropriate or unwanted behaviors, as one factor in the development and maintenance of addictive behaviors. Current literature supports disruption of the prefrontal circuits that mediate reactive inhibitory control processes (i.e. inhibition in response to sudden, unplanned changes in environmental demands) in substance use disorders, however, the relationship between disorders of addiction, such as nicotine dependence, and planned inhibitory processes is unclear. The goal of the present study was to examine the extent to which reactive and planned inhibitory processes are differentially disrupted in nicotine dependent individuals. To this aim, we employed a novel stop signal task that explicitly separates planned and reactive inhibitory processes and assessed (1) group differences in task performance between smokers and non- smokers and (2) the relationship between task performance and smoking behaviors within the smoking group. We found significant differences in stop times for both trial between groups as well as within groups. Analyses of stopping behavior in the smoking group revealed an inverse correlation between stop times on planned stop trials and a measure of nicotine dependence derived from the Fagerstrom Test of Nicotine Dependence and, surprisingly, showed that greater daily average consumption of nicotine was inversely related to stop times for both trial types. Finally, we found that recency of the last cigarette smoked was unrelated to stopping behavior.

Active Smoking Induces Aberrations in Digestive Tract Microbiota of Rats

Cigarette smoking could have certain effects on gut microbiota. Some pioneering studies have investigated effects of active smoking on the microbiome in local segments of the digestive tract, while active smoking-induced microbiome alterations in the whole digestive tract have not been fully investigated. Here, we developed a rat model of active smoking and characterized the effects of active smoking on the microbiota within multiple regions along the digestive tract. Blood glucose and some metabolic factors levels, the microbial diversity and composition, relative abundances of taxa, bacterial network correlations and predictive functional profiles were compared between the control group and active smoking group. We found that active smoking induced hyperglycemia and significant reductions in serum insulin and leptin levels. Active smoking induced region-specific shifts in microbiota structure, composition, network correlation and metabolism function along the digestive tract. Our results demonstrated that active smoking resulted in a reduced abundance of some potentially beneficial genera (i.e. Clostridium, Turicibacter) and increased abundance of potentially harmful genera (i.e. Desulfovibrio, Bilophila). Functional prediction suggested that amino acid, lipid, propanoate metabolism function could be impaired and antioxidant activity may be triggered. Active smoking may be an overlooked risk to health through its potential effects on the digestive tract microbiota, which is involved in the cause and severity of an array of chronic diseases.

Increased Risk for Cerebral Hypoxia During Immediate Neonatal Transition After Birth in Term Neonates Delivered by Caesarean Section With Prenatal Tobacco Exposure

Introduction: Maternal tobacco smoking during pregnancy is a global health problem leading to an increased risk for fetal and neonatal morbidities. So far, there are no data of the potential impact of maternal smoking during pregnancy on the most vulnerable period after birth – the immediate postnatal transition. The aim of the present study was therefore, to compare cerebral oxygenation during immediate postnatal transition in term neonates with and without prenatal tobacco exposure.Methods: Included in this post-hoc analysis were healthy term neonates, with measurements of cerebral oxygenation (INVOS 5100C) during the first 15 min after birth, and for whom information on maternal smoking behavior during pregnancy was available. Neonates with prenatal tobacco exposure (smoking group) were matched 1:1 according to gestational age (±1 week), birth weight (±100 grams) and hematocrit (±5 %) to neonates without (non-smoking group). Cerebral regional tissue oxygen saturation (crSO2), cerebral fractional tissue oxygen extraction (cFTOE), arterial oxygen saturation (SpO2) and heart rate (HR) within the first 15 min after birth were compared between the two groups.Results: Twelve neonates in the smoking group with a median (IQR) gestational age of 39.1 (38.8–39.3) weeks and a birth weight of 3,155 (2,970–3,472) grams were compared to 12 neonates in the non-smoking group with 39.1 (38.7–39.2) weeks and 3,134 (2,963–3,465) grams. In the smoking group, crSO2 was significantly lower and cFTOE significantly higher until min 5 after birth. HR was significantly higher in the smoking group in min 3 after birth. Beyond this period, there were no significant differences between the two groups.Conclusion: Cerebral oxygenation within the first 5 min after birth was compromised in neonates with prenatal tobacco exposure. This observation suggests a higher risk for cerebral hypoxia immediately after birth due to fetal tobacco exposure.

The Influence of Smoking on Choroidal, Macular and Retinal Nerve Fiber Layer Thickness

Background: Smoking is one of the most serious health hazards because it affects every organ in our bodies. Cigarette smoking increases the chance of developing systemic and ocular vascular diseases significantly. Although the exact mechanism behind the association between ocular vascular disorders and smoking are unknown, the peripheral vasoconstriction action of nicotine is believed to lead to an increase in peripheral blood flow resistance. This study was designed to examine the impact of smoking with Spectral Domain Optical Coherence Tomography (SD-OCT) on the peripapillary retinal nerve fibre (RNFL), macular, and choroidal thickness. Methods: This prospective study was done on 50. It included 25 healthy cigarette smokers with no systemic or ocular illness and another 25 age- and gender-matched healthy non-smokers. Results: The smoking group had a substantial reduction in central macular and choroidal thickness as compared to the nonsmoker group. The RNFL peripapillary thickness across groups was not significantly altered, with the exception of the temporal (T) quadrant which was significantly thinner in the smoking group. This study discovered a substantial negative correlation between peripapillary RNFL, central macular thickness, and smoking exposure. Conclusions: Smoking reduces the mean thickness of the peripapillary retinal nerve fibre layer (particularly in the temporal quadrant), the choroidal layer, and the central macular layer statistically significantly.

The Effect of Smoking on the Immune Microenvironment and Immunogenicity and Its Relationship With the Prognosis of Immune Checkpoint Inhibitors in Non-small Cell Lung Cancer

Background: The emergence of immune checkpoint inhibitors (ICIs) has opened a new chapter for the treatment of non-small cell lung cancer (NSCLC), and the best beneficiaries of ICI treatment are still being explored. Smoking status has been repeatedly confirmed to affect the efficacy of ICIs in NSCLC patients, but the specific mechanism is still unclear.Methods: We performed analysis on the Memorial Sloan Kettering Cancer Center (MSKCC) clinical NSCLC cohort receiving ICI treatment, The Cancer Genome Atlas (TCGA) Pan-Lung Cancer cohort, and Gene Expression Omnibus (GEO) database GSE41271 lung cancer cohort that did not receive ICI treatment, including survival prognosis, gene mutation, copy number variation, immunogenicity, and immune microenvironment, and explored the impact of smoking status on the prognosis of NSCLC patients treated with ICIs and possible mechanism. In addition, 8 fresh NSCLC surgical tissue samples were collected for mass cytometry (CyTOF) experiments to further characterize the immune characteristics and verify the mechanism.Result: Through the analysis of the clinical data of the NSCLC cohort treated with ICIs in MSKCC, it was found that the smokers in NSCLC receiving ICI treatment had a longer progression-free survival (HR: 0.69, 95% CI: 0.49–0.97, p = 0.031) than those who never smoked. Further analysis of the TCGA and GEO validation cohorts found that the differences in prognosis between different groups may be related to the smoking group’s higher immunogenicity, higher gene mutations, and stronger immune microenvironment. The results of the CyTOF experiment further found that the immune microenvironment of smoking group was characterized by higher expression of immune positive regulatory chemokine, and higher abundance of immune activated cells, including follicular helper CD4+ T cells, gamma delta CD4+ T cells, activated DC, and activated CD8+ T cells. In contrast, the immune microenvironment of non-smoking group was significantly enriched for immunosuppressive related cells, including regulatory T cells and M2 macrophages. Finally, we also found highly enriched CD45RAhighCD4+ T cells and CD45RAhighCD8+ T cells in the non-smoking group.Conclusion: Our research results suggest that among NSCLC patients receiving ICI treatment, the stronger immunogenicity and activated immune microenvironment of the smoking group make their prognosis better.

Decreased head circumference at birth associated with maternal tobacco smoke exposure during pregnancy on the Japanese prospective birth cohort study

Maternal tobacco smoke exposure during pregnancy impairs fetal body size, including head circumference (HC) at birth; however, the mechanism still remains unclear. This analysis using a large prospective cohort study evaluated the impact of maternal tobacco exposure on their offspring’s HC and the relationship with placental weight ratio (PWR) and placental abnormalities. Parents-children pairs (n = 84,856) were included from the 104,065 records of the Japan Environmental and Children’s Study. Maternal perinatal clinical and social information by self-administered questionnaires, offspring’s body size, and placental information were collected. Data were analyzed with binominal logistic regression analysis and path analysis. Logistic regression showed significantly elevated adjusted odds ratio (aOR) (1.653, 95% CI 1.387–1.969) for the impact of maternal smoking during pregnancy on their offspring’s smaller HC at birth. Maternal exposure to environmental tobacco smoke in the non-smoking group did not increase aOR for the smaller HC. Path analysis showed that maternal smoking during pregnancy decreased the offspring’s HC directly, but not indirectly via PWR or placental abnormalities. The quitting smoking during pregnancy group did not increase aOR for the smaller HC than the non-smoking group, suggesting that quitting smoking may reduce their offspring’s neurological impairment even after pregnancy.

The effect of smoking on the plasma concentration of tricyclic antidepressants: a systematic review

Smoking is highly prevalent in the psychiatric population, and hospital admittance usually results in partial or complete smoking cessation. Tobacco use is known to affect the metabolism of certain psychoactive drugs, but whether smoking influences the plasma concentration of tricyclic antidepressants (TCAs) remains unclear. This article investigates the possible effect of smoking on the plasma concentration of TCAs. A systematic review of the literature available on PubMed and EMBASE as of October 2020 was carried out using PRISMA guidelines. Studies reporting plasma concentrations of any TCA in both a smoking and a non-smoking group were included and compared. Ten eligible studies were identified and included. In the eight studies investigating the effect of smoking on amitriptyline and/or nortriptyline, five studies found no significant effect. Two studies investigating the effect of smoking on imipramine found a significant effect, and one study investigating the effect of smoking on doxepin found no significant effect. The majority of studies included in this review were influenced by small study populations and other methodical issues. The effect of smoking on the plasma concentration of TCAs is still not entirely clear. There is a possibility that smoking affects the distribution of TCA metabolites, but this is probably not of clinical importance.

The Differences and Changes of Semi-Quantitative and Quantitative CT Features of Coronavirus Disease 2019 Pneumonia in Patients With or Without Smoking History

Objective: To assess CT features of COVID-19 patients with different smoking status using quantitative and semi-quantitative technologies and to investigate changes of CT features in different disease states between the two groups.Methods: 30 COVID-19 patients with current smoking status (29 men, 1 woman) admitted in our database were enrolled as smoking group and 56 COVID-19 patients without smoking history (24 men, 32 women) admitted during the same period were enrolled as a control group. Twenty-seven smoking cases and 55 control cases reached recovery standard and were discharged. Initial and follow-up CT during hospitalization and follow-up CT after discharge were acquired. Thirty quantitative features, including the ratio of infection volume and visual-assessed interstitial changes score including total score, score of ground glass opacity, consolidation, septal thickening, reticulation and honeycombing sign, were analyzed.Results: Initial CT images of the smoking group showed higher scores of septal thickening [4.5 (0–5) vs. 0 (0–4), p = 0.001] and reticulation [0 (0–5.25) vs 0 (0–0), p = 0.001] as well as higher total score [7 (5–12.25) vs. 6 (5–7), p = 0.008] with statistical significance than in the control group. The score of reticulation was higher in the smoking group than in the control group when discharged [0.89 (0–0) vs. 0.09 (0–0), p = 0.02]. The score of septal thickening tended to be higher in the smoking group than the control group [4 (0–4) vs. 0 (0–4), p = 0.007] after being discharged. Quantitative CT features including infection ratio of whole lung and left lung as well as infection ratio within HU (−750, −300) and within HU (−300, 49) were higher in the control group of initial CT with statistical differences. The infection ratio of whole lung and left lung, infection ratio within HU (−750), and within HU (−750, −300) were higher in the control group with statistical differences when discharged. This trend turned adverse after discharge and the values of quantitative features were generally higher in the smoking group than in the control group without statistical differences.Conclusions: Patients with a history of smoking presented more severe interstitial manifestations and more residual lesion after being discharged. More support should be given for COVID-19 patients with a smoking history during hospitalization and after discharge.

Maternal smoking during pregnancy and asthma during the first year of life: a comparative study between smokers and non-smoker mothers

Background: We investigated the relationship between maternal smoking in pregnancy and health care problems in the offspring during the first year of life, particularly asthma.Material and Methods: A cohort of 648 consecutive infants born at term and alive at Hospitalde Sagunto (Valencia, Spain) over one year period was followed for 12 months. Clinical data of the infants were prospectively collected from the database of ambulatory medical records (ABUCASIS) of the Valencia health system.Results: Smoking during pregnancy was recorded in 164 (25.3%) mothers. During the first year of life, asthma was diagnosed in 101 infants, with an incidence of 15.7%. The diagnoses of asthma (25.6% vs. 12.3%; P < 0.0001) and bronchiolitis (44.5% vs. 28.6%; P = 0.0002) during the first year of life were more common among infants in the smoking group. The probability of developing asthma during the first year of life was two-fold higher for the male gender and 2.5 times higher when mothers smoked while pregnant. Up to 52% of asthma cases could have been avoided in infants born to smoking mothers if they did not smoke during pregnancy. Infants in the smoking group showed a lower weight and length at birth than infants in the nonsmoking group differences almost disappeared at 6 months and 12 months.Conclusion: Asthma during the first year of life showed a clear relationship with maternal smoking in pregnancy. Pregnant women should be advised of the significant perinatal risk for respiratory diseases associated with tobacco use.