Sex-related DNA methylation is associated with inflammation and gene expression in the lungs of healthy individuals.

Lung cancer exhibits sex-biased molecular characteristics and epidemiological trends, suggesting a need for sex-specific approaches to understanding its etiology and treatment. DNA methylation alterations play critical roles in lung carcinogenesis and may serve as valuable biomarkers for precision medicine strategies. We employed the Infinium MethylationEPIC array to identify autosomal sex-related differentially methylated CpG sites (DM-CpGs) in lung epithelium of healthy individuals (32 females and 37 males) while controlling for age, BMI, and tobacco use. We correlated DM-CpGs with gene expression in lung epithelium and immune responses in bronchoalveolar lavage. We validated these DM-CpGs in lung tumors and adjacent normal tissue from The Cancer Genome Atlas (TCGA). Among 522 identified DM-CpGs, 61% were hypermethylated in females, predominantly located in promoter regions. These DM genes were implicated in cell-to-cell signaling, cellular function, transport, and lipid metabolism. Correlation analysis revealed sex-specific patterns between DM-CpGs and gene expression. Additionally, several DM-CpGs were correlated significantly with cytokines (IL-1ß, IL-4, IL-12p70, and IFN-γ), macrophage, and lymphocyte counts. Also, some DM-CpGs were observed in TCGA lung adenocarcinoma, squamous cell carcinoma, and adjacent normal tissues. Our findings highlight sex-specific DNA methylation patterns in healthy lung epithelium and their associations with lung gene expression and lung immune biomarkers. These findings underscore the potential role of lung sex-related CpGs as epigenetic predispositions influencing sex disparities in lung cancer risk and outcomes, warranting further investigation for personalized lung cancer management strategies.

mRNA vaccines against SARS-CoV-2 induce divergent antigen-specific T-cell responses in patients with lung cancer.

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant is highly transmissible and evades pre-established immunity. Messenger RNA (mRNA) vaccination against ancestral strain spike protein can induce intact T-cell immunity against the Omicron variant, but efficacy of booster vaccination in patients with late-stage lung cancer on immune-modulating agents including anti-programmed cell death protein 1(PD-1)/programmed death-ligand 1 (PD-L1) has not yet been elucidated. METHODS: We assessed T-cell responses using a modified activation-induced marker assay, coupled with high-dimension flow cytometry analyses. Peripheral blood mononuclear cells (PBMCs) were stimulated with various viral peptides and antigen-specific T-cell responses were evaluated using flow cytometry. RESULTS: Booster vaccines induced CD8+ T-cell response against the ancestral SARS-CoV-2 strain and Omicron variant in both non-cancer subjects and patients with lung cancer, but only a marginal induction was detected for CD4+ T cells. Importantly, antigen-specific T cells from patients with lung cancer showed distinct subpopulation dynamics with varying degrees of differentiation compared with non-cancer subjects, with evidence of dysfunction. Notably, female-biased T-cell responses were observed. CONCLUSION: We conclude that patients with lung cancer on immunotherapy show a substantial qualitative deviation from non-cancer subjects in their T-cell response to mRNA vaccines, highlighting the need for heightened protective measures for patients with cancer to minimize the risk of breakthrough infection with the Omicron and other future variants.

COVID-19 or Cancer Stress? Anxiety and Depressive Symptoms in Patients with Advanced Lung Cancer.

BACKGROUND: Of all cancer patients, those with lung cancer are among the highest risk for infection, pneumonia, hospitalization, and early death from COVID-19. As cancer stress is ubiquitous, this exploratory study examines patients' COVID-19 stress and cancer stress in relation to their depressive and anxiety symptoms. METHOD: Newly diagnosed advanced lung cancer patients (N = 76) completed measures of cancer stress, COVID-19 illness perceptions and stress, and depressive and anxiety symptoms at a single monthly follow-up early in the pandemic (May 2020 to July 2020; Clinicaltrials.gov #NCT03199651). Hierarchical linear multiple regression analysis was used to identify the relationship of stressor variables to depressive and anxiety symptoms in this cross-sectional study. RESULTS: Hierarchical linear models revealed cancer stress was a significant predictor of both depressive symptoms (F(14,30) = 5.327, p < 0.001, R2 = 0.71, adjusted R2 = 0.58) and anxiety symptoms (F(14,30) = 4.513, p < 0.001, R2 = 0.68, adjusted R2 = 0.53) for patients at the start of the COVID-19 pandemic. By contrast, COVID-19 stress was not a significant predictor of depressive (F(13,31) = 1.415 p = .21, R2 = .37, adjusted R2 = .11) or anxiety symptoms (F(13,31) = 1.23, p = .30, R2 = .34, adjusted R2 = - .07). CONCLUSIONS: Advanced lung cancer patients during the early phase of the COVID-19 pandemic reported cancer stress as more important than COVID-19 stress in relation to their mental health. Empirically supported biobehavioral and cognitive behavioral treatments remain important to reducing psychological symptoms and enhancing patients' quality of life.

Accelerated epigenetic age, inflammation, and gene expression in lung: comparisons of smokers and vapers with non-smokers.

BACKGROUND: Cigarette smoking and aging are the main risk factors for pulmonary diseases, including cancer. Epigenetic aging may explain the relationship between smoking, electronic cigarette vaping, and pulmonary health. No study has examined smoking and vaping-related epigenetic aging in relation to lung biomarkers. METHODS: Lung epigenetic aging measured by DNA methylation (mAge) and its acceleration (mAA) was assessed in young (age 21-30) electronic cigarette vapers (EC, n = 14, including 3 never-smoking EC), smokers (SM, n = 16), and non-EC/non-SM (NS, n = 39). We investigated relationships of mAge estimates with chronological age (Horvath-mAge), lifespan/mortality (Grim-mAge), telomere length (TL-mAge), smoking/EC history, urinary biomarkers, lung cytokines, and transcriptome. RESULTS: Compared to NS, EC and SM had significantly older Grim-mAge, shorter TL-mAge, significantly accelerated Grim-mAge and decelerated TL-mAge. Among SM, Grim-mAA was associated with nicotine intake and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL). For EC, Horvath-mAA was significantly correlated with puffs per day. Overall, cytokines (IL-1ß, IL-6, and IL-8) and 759 transcripts (651 unique genes) were significantly associated with Grim-mAA. Grim-mAA-associated genes were highly enriched in immune-related pathways and genes that play a role in the morphology and structures of cells/tissues. CONCLUSIONS: Faster lung mAge for SM is consistent with prior studies of blood. Faster lung mAge for EC compared to NS indicates possible adverse pulmonary effects of EC on biological aging. Our findings support further research, particularly on epigenetic markers, on effects of smoking and vaping on pulmonary health. Given that most EC are former smokers, further study is needed to understand unique effects of electronic cigarettes on biological aging.

Untargeted Metabolomics and Body Mass in Adolescents: A Cross-Sectional and Longitudinal Analysis.

Obesity in children and adolescents has increased globally. Increased body mass index (BMI) during adolescence carries significant long-term adverse health outcomes, including chronic diseases such as cardiovascular disease, stroke, diabetes, and cancer. Little is known about the metabolic consequences of changes in BMI in adolescents outside of typical clinical parameters. Here, we used untargeted metabolomics to assess changing BMI in male adolescents. Untargeted metabolomic profiling was performed on urine samples from 360 adolescents using UPLC-QTOF-MS. The study includes a baseline of 235 subjects in a discovery set and 125 subjects in a validation set. Of them, a follow-up of 81 subjects (1 year later) as a replication set was studied. Linear regression analysis models were used to estimate the associations of metabolic features with BMI z-score in the discovery and validation sets, after adjusting for age, race, and total energy intake (kcal) at false-discovery-rate correction (FDR) ≤ 0.1. We identified 221 and 16 significant metabolic features in the discovery and in the validation set, respectively. The metabolites associated with BMI z-score in validation sets are glycylproline, citrulline, 4-vinylsyringol, 3'-sialyllactose, estrone sulfate, carnosine, formiminoglutamic acid, 4-hydroxyproline, hydroxyprolyl-asparagine, 2-hexenoylcarnitine, L-glutamine, inosine, N-(2-Hydroxyphenyl) acetamide glucuronide, and galactosylhydroxylysine. Of those 16 features, 9 significant metabolic features were associated with a positive change in BMI in the replication set 1 year later. Histidine and arginine metabolism were the most affected metabolic pathways. Our findings suggest that obesity and its metabolic outcomes in the urine metabolome of children are linked to altered amino acids, lipid, and carbohydrate metabolism. These identified metabolites may serve as biomarkers and aid in the investigation of obesity's underlying pathological mechanisms. Whether these features are associated with the development of obesity, or a consequence of changing BMI, requires further study.

A Pilot Cross-Sectional Study of Immunological and Microbiome Profiling Reveals Distinct Inflammatory Profiles for Smokers, Electronic Cigarette Users, and Never-Smokers.

Smokers (SM) have increased lung immune cell counts and inflammatory gene expression compared to electronic cigarette (EC) users and never-smokers (NS). The objective of this study is to further assess associations for SM and EC lung microbiomes with immune cell subtypes and inflammatory gene expression in samples obtained by bronchoscopy and bronchoalveolar lavage (n = 28). RNASeq with the CIBERSORT computational algorithm were used to determine immune cell subtypes, along with inflammatory gene expression and microbiome metatranscriptomics. Macrophage subtypes revealed a two-fold increase in M0 (undifferentiated) macrophages for SM and EC users relative to NS, with a concordant decrease in M2 (anti-inflammatory) macrophages. There were 68, 19, and 1 significantly differentially expressed inflammatory genes (DEG) between SM/NS, SM/EC users, and EC users/NS, respectively. CSF-1 and GATA3 expression correlated positively and inversely with M0 and M2 macrophages, respectively. Correlation profiling for DEG showed distinct lung profiles for each participant group. There were three bacteria genera-DEG correlations and three bacteria genera-macrophage subtype correlations. In this pilot study, SM and EC use were associated with an increase in undifferentiated M0 macrophages, but SM differed from EC users and NS for inflammatory gene expression. The data support the hypothesis that SM and EC have toxic lung effects influencing inflammatory responses, but this may not be via changes in the microbiome.

Depression in association with neutrophil-to-lymphocyte, platelet-to-lymphocyte, and advanced lung cancer inflammation index biomarkers predicting lung cancer survival.

Lung cancer is a product of inflammation and a dysfunctional immune system, and depression has similar dysregulation. Depression disproportionately affects lung cancer patients, having the highest rates of all cancers. Systemic inflammation and depression are both predictive of non-small cell lung cancer (NSCLC) survival, but the existence and extent of any co-occurrence is unknown. Studied is the association between systemic inflammation ratio (SIR) biomarker levels and patients' depressive symptoms, with the hypothesis that depression severity would be significantly associated with prognostically poor inflammation. Newly diagnosed stage-IV non-small cell lung cancer (NSCLC; N = 186) patients were enrolled (ClinicalTrials.gov Identifier: NCT03199651) and blood draws and depression self-reports (Patient Health Questionnaire-9) were obtained. For SIRs, cell counts of neutrophils (N), lymphocytes (L), and platelets (P) were abstracted for ratio (R) calculations for NLR, PLR, and the Advanced Lung cancer Inflammation Index (ALI). Patients were followed and biomarkers were tested as predictors of 2-year overall survival (OS) to confirm their relevance. Next, multivariate linear regressions tested associations of depression with NLR, PLR, and ALI. Overall 2-year mortality was 61% (113/186). Cox model analyses confirmed higher NLR [hazard ratio (HR) = 1.91; p = 0.001] and PLR (HR = 2.08; p<0.001), along with lower ALI (HR = 0.53; p = 0.005), to be predictive of worse OS. Adjusting for covariates, depression was reliably associated with biomarker levels (p ≤ 0.02). Patients with moderate/severe depressive symptoms were 2 to 3 times more likely to have prognostically poor biomarker levels. Novel data show patients' depressive symptoms were reliably associated with lung-relevant systemic inflammation biomarkers, all assessed at diagnosis/pretreatment. The same SIRs were found prognostic for patients' 2-year OS. Intensive study of depression, combined with measures of cell biology and inflammation is needed to extend these findings to discover mechanisms of depression toxicity for NSCLC patients' treatment responses and survival.

Selective suppression of de novo SARS-CoV-2 vaccine antibody responses in patients with cancer on B cell-targeted therapy.

We assessed vaccine-induced antibody responses to the SARS-CoV-2 ancestral virus and Omicron variant before and after booster immunization in 57 patients with B cell malignancies. Over one-third of vaccinated patients at the pre-booster time point were seronegative, and these patients were predominantly on active cancer therapies such as anti-CD20 monoclonal antibody. While booster immunization was able to induce detectable antibodies in a small fraction of seronegative patients, the overall booster benefit was disproportionately evident in patients already seropositive and not receiving active therapy. While ancestral virus- and Omicron variant-reactive antibody levels among individual patients were largely concordant, neutralizing antibodies against Omicron tended to be reduced. Interestingly, in all patients, including those unable to generate detectable antibodies against SARS-CoV-2 spike, we observed comparable levels of EBV- and influenza-reactive antibodies, demonstrating that B cell-targeting therapies primarily impair de novo but not preexisting antibody levels. These findings support rationale for vaccination before cancer treatment.

Risk perceptions and continued smoking as a function of cigarette filter ventilation level among US youth and young adults who smoke.

BACKGROUND: While evidence demonstrates that the industry's marketing of cigarettes with higher filter ventilation (FV) misleads adults about their health risks, there is no research on the relationships between FV, risk perceptions and smoking trajectories among youth (ages 12-17) and young adults (ages 18-24). METHODS: Data on FV levels of major US cigarette brands/sub-brands were merged with the Population Assessment of Tobacco and Health Study to examine whether FV level in cigarettes used by wave 1 youth/young adults (n=1970) predicted continued smoking at waves 2-4, and whether those relationships were mediated by perceived risk of their cigarette brand. FV was modelled based on tertiles (0.2%-11.8%, low; 11.9%-23.2%, moderate; 23.3%-61.1%, high) to predict daily smoking, past 30-day smoking and change in number of days smoking at successive waves. RESULTS: The odds of perceiving one's brand as less harmful than other cigarette brands was 2.21 times higher in the high versus low FV group (p=0.0146). Relationships between FV and smoking outcomes at successive waves were non-significant (all p>0.05). CONCLUSION: Youth and young adults who use higher FV cigarettes perceived their brand as less harmful compared with other brands. However, level of FV was not associated with continued smoking.

Lung mitochondrial DNA copy number, inflammatory biomarkers, gene transcription and gene methylation in vapers and smokers.

BACKGROUND: Mitochondrial DNA copy number (mtCN) maintains cellular function and homeostasis, and is linked to nuclear DNA methylation and gene expression. Increased mtCN in the blood is associated with smoking and respiratory disease, but has received little attention for target organ effects for smoking or electronic cigarette (EC) use. METHODS: Bronchoscopy biospecimens from healthy EC users, smokers (SM), and never-smokers (NS) were assessed for associations of mtCN with mtDNA point mutations, immune responses, nuclear DNA methylation and gene expression using linear regression. Ingenuity pathway analysis was used for enriched pathways. GEO and TCGA respiratory disease datasets were used to explore the involvement of mtCN-associated signatures. FINDINGS: mtCN was higher in SM than NS, but EC was not statistically different from either. Overall there was a negative association of mtCN with a point mutation in the D-loop but no difference within groups. Positive associations of mtCN with IL-2 and IL-4 were found in EC only. mtCN was significantly associated with 71,487 CpGs and 321 transcripts. 263 CpGs were correlated with nearby transcripts for genes enriched in the immune system. EC-specific mtCN-associated-CpGs and genes were differentially expressed in respiratory diseases compared to controls, including genes involved in cellular movement, inflammation, metabolism, and airway hyperresponsiveness. INTERPRETATION: Smoking may elicit a lung toxic effect through mtCN. While the impact of EC is less clear, EC-specific associations of mtCN with nuclear biomarkers suggest exposure may not be harmless. Further research is needed to understand the role of smoking and EC-related mtCN on lung disease risks. FUNDING: The National Cancer Institute, the National Heart, Lung, and Blood Institute, the Food and Drug Administration Center for Tobacco Products, the National Center For Advancing Translational Sciences, and Pelotonia Intramural Research Funds.

Functional Trajectories and Resilience Among Adults With Advanced Lung Cancer.

Introduction: To evaluate whether and the degree to which patients with advanced NSCLC (aNSCLC) receiving lung cancer treatments will experience functional disability or have resilience and to identify characteristics associated with functional disability. Methods: We evaluated longitudinal data of patients with aNSCLC receiving treatment in the Beating Lung Cancer in Ohio prospective cohort study. Disability versus resilience in functional status (usual activities, mobility, and self-care) was measured monthly for 8 months using the EuroQol-5D-5L. Data captured included baseline demographics (Eastern Cooperative Oncology Group performance status), comorbidities, cancer and depressive symptoms (Patient Health Questionnaire-9), anxiety (Generalized Anxiety Disorder-7 scale), and cancer stress (impact of events). Group-based latent class trajectory modeling was used to determine clinically distinct functional disability trajectories jointly with attrition probability (death or withdrawal) in the study period. Results: Among 207 participants, the mean age was 63.5 years (range: 34-92 y), 58.9% were male, 6.8% were African American or Black, 73.3% were former smokers, and 35% resided in rural areas. At baseline, participants had adenocarcinoma histological subtype (74.9%), 40.3% had brain metastases, and 46.1% had bone metastases. Participants received chemotherapy plus immunotherapy (46.9%), immunotherapy single agent (21.7%), targeted treatments (18.8%), or no treatment (12.6%). Three distinct functional trajectory groups were identified, as follows: none/mild (n = 79, 38.2%), moderate (n = 99, 47.8%), and severe disability (n = 29, 14.0%). Characteristics associated with severe disability included baseline Eastern Cooperative Oncology Group performance status greater than 1, worse dyspnea and pain, and higher Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 scale scores. At month 8, 95 participants (45.9%) displayed resilience, 11 (5.3%) experienced functional decline, and 69 (33.3%) were deceased. Conclusions: We identified three distinct functional trajectories among patients with aNSCLC. Risk stratification tools and targeted interventions designed to target these three groups are needed to improve functional resilience and prevent disability.

Cancer Treatment During COVID-19: Resilience of Individuals With Advanced Non-Small Cell Lung Cancer Versus Community Controls.

BACKGROUND: Among all patients with cancer, those with advanced non-small cell lung cancer (NSCLC) experience the most distress. Although new therapies are improving survival, it is unknown whether receiving immunotherapy or targeted therapy during the COVID-19 pandemic increases patients' psychological vulnerability. To meet clinical needs, knowledge of patients' COVID-19 perceptions and safety behaviors is essential. Thus, this study compared patients' psychological responses at diagnosis and during COVID-19 and compared patients with similar individuals without cancer during the same period. PATIENTS AND METHODS: Patients with advanced NSCLC enrolled at diagnosis for cohort study participated (ClinicalTrials.gov identifier: NCT03199651). Those with follow-ups from April 28, 2020, through July 14, 2020 (n=76), were assessed again including COVID-19 measures. Simultaneously, community controls with similar sociodemographics and smoking histories were solicited (n=67). Measures were COVID-19 perceptions (Brief Illness Perception Questionnaire), social distancing, and depressive (Patient Health Questionnaire-9) and anxiety (Generalized Anxiety Disorder-7) symptoms. First, analyses evaluated differences in the psychological responses of patients with NSCLC at diagnosis and during COVID-19. Second, patients and controls were contrasted on COVID-19 perceptions, social distancing, and psychological symptoms. RESULTS: The depressive and anxious symptoms of patients with NSCLC were greater at diagnosis (P<.02) than during COVID-19, approximately 1 year later. Patients with NSCLC and controls did not differ in terms of sociodemographics, except those with NSCLC were more racially diverse and older, and had greater smoking history (P<.03). Groups did not differ regarding concern, understanding, or perceived control over COVID-19 (P>.406). Notably, controls anticipated the COVID threat would last longer, practiced more social distancing, were more concerned about family (P<.04), and reported worse psychological symptoms (P<.023). With less depression and anxiety, patients with NSCLC viewed COVID-19 as a shorter-term threat and had fewer COVID-19-related worries than did controls. For controls, COVID-19 was more salient, heightening worries and psychological symptoms. CONCLUSIONS: Despite multiple health stressors, patients with NSCLC demonstrated resilience when receiving cancer treatment during COVID-19. Nonetheless, this population remains psychologically vulnerable, requiring support at diagnosis and thereafter.

The experimental tobacco marketplace: Effects of low-ventilated cigarette exposure.

OBJECTIVES: Regulating filter ventilation will change the relative reinforcing value of products resulting in nicotine/tobacco users facing the explore/exploit dilemma (ie, choice between unfamiliar and familiar options). This study examined the effects of price increases in higher-ventilated cigarettes (HVCs) and exposure to lower-ventilated cigarettes (LVCs) on explore/exploit patterns of tobacco-product purchasing in the Experimental Tobacco Marketplace (ETM). METHODS: HVC smokers (N = 20) completed one assessment session and 3 ETM sessions separated by weeks of at-home LVC exposure. In each ETM session, participants made 7-days of tobacco-product purchases as HVCs price increased across trials. RESULTS: Prohibitive prices of HVC decreased the likelihood of HVCs purchases and increased the likelihood of LVC purchases. Initial exposure (week 1) to LVC reduced the number of cigarettes purchased when HVC prices were high and increased exploration of alternative tobacco products. Successive exposure to LVC (repeated access in weeks 2,5,6,9,10) decreased likelihood of HVCs and alternative product purchases and increased the likelihood of LVCs purchases. CONCLUSIONS: Regulating filter ventilation may initially increase exploration of alternative tobacco products but lead to exploitation of LVCs over time. Tobacco control strategies should take advantage of this transition period when smokers seek information on unfamiliar products to implement harm reduction strategies.

Impaired neutralizing antibody response to COVID-19 mRNA vaccines in cancer patients.

There is currently a critical need to determine the efficacy of SARS-CoV-2 vaccination for immunocompromised patients. In this study, we determined the neutralizing antibody response in 160 cancer patients diagnosed with chronic lymphocytic leukemia (CLL), lung cancer, breast cancer, and various non-Hodgkin's lymphomas (NHL), after they received two doses of mRNA vaccines. Serum from 46 mRNA vaccinated health care workers (HCWs) served as healthy controls. We discovered that (1) cancer patients exhibited reduced neutralizing antibody titer (NT50) compared to HCWs; (2) CLL and NHL patients exhibited the lowest NT50 levels, with 50-60% of them below the detection limit; (3) mean NT50 levels in patients with CLL and NHL was ~2.6 fold lower than those with solid tumors; and (4) cancer patients who received anti-B cell therapy exhibited significantly reduced NT50 levels. Our results demonstrate an urgent need for novel immunization strategies for cancer patients against SARS-CoV-2, particularly those with hematological cancers and those on anti-B cell therapies.

Impaired Neutralizing Antibody Response to COVID-19 mRNA Vaccines in Cancer Patients.

There is currently a critical need to determine the efficacy of SARS-CoV-2 vaccination for immunocompromised patients. In this study, we determined the neutralizing antibody response in 160 cancer patients diagnosed with chronic lymphocytic leukemia (CLL), lung cancer, breast cancer, and various non-Hodgkin's lymphomas (NHL), after they received two doses of mRNA vaccines. Serum from 46 mRNA vaccinated health care workers (HCWs) served as healthy controls. We discovered that (1) cancer patients exhibited reduced neutralizing antibody titer (NT 50 ) compared to HCWs; (2) CLL and NHL patients exhibited the lowest NT 50 levels, with 50-60% of them below the detection limit; (3) mean NT 50 levels in patients with CLL and NHL was ∼2.6 fold lower than those with solid tumors; and (4) cancer patients who received anti-B cell therapy exhibited significantly reduced NT 50 levels. Our results demonstrate an urgent need for novel immunization strategies for cancer patients against SARS-CoV-2, particularly those with hematological cancers and those on anti-B cell therapies.

Lipid laden macrophages and electronic cigarettes in healthy adults.

BACKGROUND: An outbreak of E-cigarette or Vaping Product Use-Associated Lung Injury (EVALI) with significant morbidity and mortality was reported in 2019. While most patients with EVALI report vaping tetrahydrocannabinol (THC) oils contaminated with vitamin E acetate, a subset report only vaping with nicotine-containing electronic cigarettes (e-cigs). Whether or not e-cigs cause EVALI, the outbreak highlights the need for identifying long term health effects of e-cigs. EVALI pathology includes alveolar damage, pneumonitis and/or organizing pneumonia, often with lipid-laden macrophages (LLM). We assessed LLM in the lungs of healthy smokers, e-cig users, and never-smokers as a potential marker of e-cig toxicity and EVALI. METHODS: A cross-sectional study using bronchoscopy was conducted in healthy smokers, e-cig users, and never-smokers (n = 64). LLM, inflammatory cell counts, and cytokines were determined in bronchial alveolar fluids (BAL). E-cig users included both never-smokers and former light smokers. FINDINGS: High LLM was found in the lungs of almost all smokers and half of the e-cig users, but not those of never-smokers. LLM were not related to THC exposure or smoking history. LLM were significantly associated with inflammatory cytokines IL-4 and IL-10 in e-cig users, but not smoking-related cytokines. INTERPRETATION: This is the first report of lung LLM comparing apparently healthy smokers, e-cig users, and never-smokers. LLM are not a specific marker for EVALI given the frequent positivity in smokers; whether LLMs are a marker of lung inflammation in some e-cig users requires further study. FUNDING: The National Cancer Institute, the National Heart, Lung, and Blood Institute, the Food and Drug Administration Center for Tobacco Products, the National Center For Advancing Translational Sciences, and Pelotonia Intramural Research Funds.

Quantitation by liquid chromatography-nanoelectrospray ionization-high resolution tandem mass spectrometry of DNA adducts derived from methyl glyoxal and carboxyethylating agents in leukocytes of smokers and non-smokers.

A liquid chromatograpy-nanoelectrospray ionization-high resolution tandem mass spectrometry (LC-NSI-HRMS/MS) method was developed for quantitation of the DNA adducts 7-(2'-carboxyethyl)guanine (7-2'-CEG) and N2-(1'-carboxyethyl)guanine (N2-1'-CEG), as their methyl esters, in human leukocyte DNA from smokers and non-smokers. 7-2'-CEG has been previously identified in all human liver samples analyzed and is formed from an unknown carboxyethylating agent while N2-1'-CEG is formed from the advanced glycation endproduct methyl glyoxal. The method was applied for the analysis of these two DNA adducts in leukocyte DNA from 20 smokers and 20 non-smokers, in part to test the hypothesis that 7-2'-CEG could be formed by endogenous nitrosation, as previously observed in rats treated with nitrosodihydrouracil and nitrite. Levels of 7-2'-CEG (mean ± S.D.) were 0.6 ± 0.2 pmol/µmol dG in smokers and 0.5 ± 0.2 pmol/µmol dG in non-smokers, while those of N2-1'-CEG were 4.5 ± 1.9 pmol/µmol dG in smokers and 4.6 ± 2 pmol/µmol dG in non-smokers. These results did not support our hypothesis that endogenous nitrosation of dihydrouracil in smokers leads to higher levels of 7-2'-CEG in leukocyte DNA than in non-smokers. However the study provides the first data on levels of these DNA adducts in human leukocyte DNA, and the LC-NSI-HRMS/MS method developed for their quantitation could be important for future studies of DNA damage by methyl glyoxal.

A Randomized Clinical Trial of Snus Examining the Effect of Complete Versus Partial Cigarette Substitution on Smoking-Related Behaviors, and Biomarkers of Exposure.

INTRODUCTION: This 8-week multisite, randomized controlled trial of snus examined the differential effects of instructions on (1) snus use, (2) smoking and smoking-related measures, and (3) exposure to tobacco-related constituents. METHOD: US adult daily cigarette smokers (n = 150; 43.3% female; Medianage = 43.5) were recruited from Minneapolis, Minnesota; Columbus and Coshocton, Ohio; and Buffalo, New York. Following a 1-week sampling phase of snus, participants who used at least 7 pouches were randomized to either (1) partial substitution (PS; "use snus as you like with your cigarettes"), (2) complete substitution (CS; "avoid cigarettes"), or (3) usual brand cigarettes (UB). Analyses included between-group analyses (eg, PS vs. CS) using Wilcoxon rank sum test of cigarettes per day and snus pouches per day, and a linear mixed model (biomarkers). RESULTS: Compared to the PS and UB groups, smokers assigned to CS reported greater reductions in cigarettes per day (ps < .001), using more snus pouches per day (p = .02), and more smoke-free days (CS median = 14.5, PS and UB medians = 0, p < .001). In addition, results demonstrated reductions in carbon monoxide (p < .001), total nicotine equivalents (p = .02), and four out of five measured volatile organic compounds (ps < .01) over time among the CS group. Exposure to N'-nitrosonornicotine increased by trial end only among the PS group (p < .04). Phenanthrene tetraol increased among all groups by trial end (p = .02) with no difference between groups. CONCLUSIONS: Instructions to completely switch from cigarettes to snus resulted in the greatest reduction in cigarettes and exposure to harmful constituents. IMPLICATIONS: Directly instructing smokers to switch completely to snus, rather than using ad libitum (with no instructions to avoid cigarettes), is necessary for reductions in smoking and subsequent exposure to harmful constituents.