Longitudinal relation between smoking and white blood cells

The relationship between heated cigarette smoking and blood white blood cell count: a population-based cross-sectional study

OBJECTIVES

Conventional cigarette smoking increases inflammation and white blood cell (WBC) counts. However, there have been limited studies on the relationship between heated cigarette smoking and WBC counts. This study aimed to examine this relationship using nationally representative population-based health data.

STUDY DESIGN

This was a population-based cross-sectional study.

METHODS

The Korea National Health and Nutrition Examination Survey database was used to analyze this relationship. Data related to sex, age, body mass index (BMI), WBC count, and smoking history were obtained from the database. The smoking-related questionnaires included smoking status, smoking type (heated or conventional cigarettes), and smoking amount. The summary statistics of the WBC counts were calculated according to sex, smoking status, and smoking type. In addition, the exposure-response relationship between the smoking amount and WBC count was examined by smoking type, controlling for sex, age, and BMI.

RESULTS

In total, 9747 WBC measurements were used in the analyses. WBC count increased in conventional cigarette smokers, while there was no significant difference in WBC count between heated cigarette smokers and non-smokers. The WBC count showed a positive dose-response relationship with the smoking amount in both conventional and heated cigarette smokers.

CONCLUSIONS

The results confirm that conventional cigarette smoking increases WBC counts. Furthermore, the results suggest that heated cigarette smoking does not lead to a significant increase in WBC counts, although it indicates a potential dose-response relationship with WBC count. Further research with larger sample sizes is needed to confirm whether these results reflect true associations.

Genetically influenced tobacco and alcohol use behaviors impact erythroid trait variation

Genome wide association studies (GWAS) have associated thousands of loci with quantitative human blood trait variation. Blood trait associated loci and related genes may regulate blood cell-intrinsic biological processes, or alternatively impact blood cell development and function via systemic factors and disease processes. Clinical observations linking behaviors like tobacco or alcohol use with altered blood traits can be subject to bias, and these trait relationships have not been systematically explored at the genetic level. Using a Mendelian randomization (MR) framework, we confirmed causal effects of smoking and drinking that were largely confined to the erythroid lineage. Using multivariable MR and causal mediation analyses, we confirmed that an increased genetic predisposition to smoke tobacco was associated with increased alcohol intake, indirectly decreasing red blood cell count and related erythroid traits. These findings demonstrate a novel role for genetically influenced behaviors in determining human blood traits, revealing opportunities to dissect related pathways and mechanisms that influence hematopoiesis.

Association between electronic cigarettes use and whole blood cell among adults in the USA-a cross-sectional study of National Health and Nutrition Examination Survey analysis

Electronic cigarettes (E-cigarettes) use is an emerging public health problem. Trying to assess the independent associations between E-cigarettes use and whole blood cell in a nationally representative sample of the US adults is very important for the smoking population. Using E-cigarettes data from NHANES (National Health and Nutrition Examination Survey) 2013-2018, 17,180 adults were included in this cross-sectional analysis. All participants were stratified into four different groups (non-smoke group N=10087, E-cigarettes group N=52, dual-smoke group N=249, cigarettes group N=6792) based on questions SMQ020 (smoked at least 100 cigarettes in life) and SMQ690H (used last 5 days E-cigarettes). Whole blood cell tests included white blood cell (WBC) with differentials, red blood cell (RBC) with characteristics, and platelet variables. With adjusted by age, gender, and race ethnicity, multivariate logistic regression analyses were used to assess independent associations between E-cigarettes group and other groups for different whole blood cell variables. A total of 17,180 participants were included in the study; 47.9% were males, with a mean age of 46.99 (±0.29). In WBC-related variables, non-smoke group had the lowest value in WBC counts (7.15±0.05), lymphocyte (2.15±0.02), and monocyte (0.57±0.01), among the four different groups. In RBC-related variables, non-smoke group had the lowest value in mean cell volume (MCV, 88.46±0.14, p<0.05) and mean cell hemoglobin (MCH, 29.73±0.06, p<0.05), among the four different groups. In adjusted analysis, WBC (OR = 0.97, 95% CI: 0.96-0.98, p<0.001), especially lymphocyte (OR = 0.97, 95% CI: 0.96-0.98, p<0.001) and monocyte (OR = 0.11, 95% CI: 0.02-0.66, p<0.001) of non-smoke group, showed negative significant effect for E-cigarettes group. Meanwhile, lower odds of MCV (OR = 0.91, 95% CI: 0.81-1.04, p<0.05) and MCH (OR = 0.81, 95% CI: 0.65-1.00, p<0.05) in non-smoke group were observed compared to E-cigarettes group. Conversely, for dual-smoke group and cigarette group, there was no significant results in all whole blood cell variables compared to E-cigarettes group. E-cigarettes use might be associated with a systemic response that could lead to an increase in WBC, especially lymphocytes and monocytes, in the US adults. Meanwhile, the properties of RBC might also be influenced simultaneously; MCV and MCH in E-cigarettes population were bigger than the non-smoke population.

Inflammation and atherogenic markers in patients with type 2 diabetes mellitus

Type two diabetes mellitus (T2DM) is characterized by a chronic inflammation status. Altered markers such as lipid concentrations are usually found in this disease. Elevated inflammation markers have been described such as cytokines (interleukin 6, tumour necrosis factor-alpha, and IL-8). However, there is a lack of information about the behaviour of the neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), lymphocyte-monocyte ratio (LMR), lipid coefficients, and atherogenic index in T2DM.

OBJECTIVE

To describe the atherogenic and inflammation parameters in a group of patients with T2DM.

MATERIALS AND METHODS

42 patients with T2DM were included, all patients were surveyed on clinic history (disease history, comorbidity, smoking, and other relevant variables), measurements of haematological, biochemical, and anthropometric parameters were taken and atherogenic coefficients and inflammation ratios were calculated.

RESULTS

Inflammation markers such as interleukin 6 and 8, necrosis tumour factor, and NLR were elevated. Of the patients, 88% were classified as high risk according to the atherogenic index. Former smokers had lower levels of IL-8 and higher NLR than non-smokers.

CONCLUSION

The atherogenic and inflammation markers such as atherogenic index, IL-8, and NLR make it possible to identify a subgroup of patients that are at risk of severe complications and mortality.

Electronic cigarette use and its association with asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap syndrome among never cigarette smokers

INTRODUCTION

Although smoking is a strong risk factor for lung diseases including asthma, COPD, and asthma-COPD overlap syndrome (ACOS), studies are needed to examine the association between e-cigarettes and asthma, COPD, and ACOS. This study evaluated the association between e-cigarette use and self-reported diagnosis of asthma, COPD, and ACOS using a large nationally representative sample of adults aged ≥18 years in the United States.

METHODS

Cross-sectional data from the Behavioral Risk Factor Surveillance System (BRFSS) from 2016 to 2018 were used to examine self-reported information on current e-cigarette use, demographic variables, and asthma and COPD status among never cigarette smokers (n=8736). Asthma and COPD were measured by self-reported diagnosis, and respondents who reported having both diagnoses were then classified as having ACOS. Of the 469077 never cigarette smokers, 4368 non-e-cigarette users were 1:1 propensity score-matched to e-cigarette users on age, sex, race/ethnicity and education level. We used multinomial logistic regression to examine association between current e-cigarette use and self-report asthma, COPD, and ACOS while controlling for marital status and employment in addition to matching variables.

RESULTS

Compared with never e-cigarette users, e-cigarette users had increased odds of self-reported ACOS (OR=2.27; 95% CI: 2.23–2.31), asthma (OR=1.26; 95% CI: 1.25–1.27) and COPD (OR=1.44; 95% CI: 1.42–1.46).

CONCLUSIONS

Our findings suggest that e-cigarette use is associated with an increased odds of self-reported asthma, COPD, and ACOS among never combustible cigarette smokers. BRFSS provides cross-sectional survey data, therefore a causal relationship between e-cigarette use and the three lung diseases cannot be evaluated. Future longitudinal studies are needed to validate these findings.

Urinary Polycyclic Aromatic Hydrocarbon Metabolites Are Associated with Biomarkers of Chronic Endocrine Stress, Oxidative Stress, and Inflammation in Adolescents: FLEHS-4 (2016-2020)

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants of public health concern. Multiple biological mechanisms have been hypothesized to contribute to PAHs-associated adverse health effects. Little is known about the impact of PAHs on endocrine stress and inflammation in adolescence. We examined 393 Flemish adolescents (14-15 years) cross-sectionally, measured urinary concentrations of hydroxylated naphthalene, fluorene, phenanthrene and pyrene metabolites, and calculated the sum of all measured metabolites. We determined hair cortisol concentration (HCC) as endocrine stress biomarker, leucocyte counts and neutrophil-lymphocyte ratio (NLR) in peripheral blood as inflammatory biomarkers, and urinary 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) concentration as oxidative stress biomarker. Exposure-response associations were analyzed by multiple regression, adjusted for a priori selected covariates. A doubling of 1-hydroxypyrene concentration was associated with a factor of 1.13 (95% CI: 1.03, 1.24) increase in HCC and a factor of 1.07 (95% CI: 1.02, 1.13) increase in 8-oxodG. Doublings of 2- and 3-hydroxyphenanthrene concentrations were associated with a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.00, 1.12) increase in 8-oxodG, respectively. Doubling of 2-hydroxyphenanthrene and of the sum of 2- and 3-hydroxyfluorene was associated with, respectively, a factor of 1.08 (95% CI: 1.02, 1.14) and 1.06 (95% CI: 1.01, 1.13) increase in NLR. Our results indicate the glucocorticoid pathway as a potential target for PAH exposure in adolescents and suggest oxidative stress, endocrine stress, and inflammation in adolescence as underlying mechanisms and early markers for PAH-related adverse health effects.

Long-term residential exposure to air pollution is associated with hair cortisol concentration and differential leucocyte count in Flemish adolescent boys

BACKGROUND

Exposure to air pollution and traffic noise are associated with adverse health outcomes in adolescents. Chronic endocrine stress and systemic inflammation have been hypothesized to underlie the adverse health effects. Simultaneous assessment of inflammation and chronic endocrine stress in epidemiological studies is lacking. The aim of the study was to investigate biomarkers of chronic endocrine stress and inflammation in relation to long-term residential exposure to air pollution and traffic noise in adolescents.

METHODS

In Flemish adolescents (14-15 years), we determined hair cortisol concentration (HCC) as a chronic stress biomarker in 3-cm scalp-near hair sections (n = 395), and leucocyte and leucocyte subtype counts (neutrophils, monocytes, lymphocytes) as inflammatory biomarkers in peripheral blood (n = 385). Daily particulate matter (PM_2.5, PM₁₀), nitrogen dioxide (NO₂) and black carbon (BC) concentrations were modelled at the residential address and averaged over 3-month and 1-year periods prior to sampling. Residential traffic noise level was estimated and classified in 5 dB intervals. Sex-specific associations between residential exposures and effect biomarkers were studied using linear regression models, adjusted for a priori selected covariates.

RESULTS

In boys, HCC increased with a factor 1.30 (95% CI: 1.10, 1.54) for an increase in 1-year mean NO₂ from the 25th to 75th percentile (p75/p25), after adjustment for age, BMI, personal and neighborhood socioeconomic status. The corresponding estimate for PM₁₀ was 1.24 (95% CI: 1.02, 1.51). Total leucocyte count in boys, adjusted for the aforementioned covariates and recent health complaints, was positively associated with PM_2.5, PM₁₀, NO₂ and BC. In particular, the neutrophil count increased with a factor 1.11 (95% CI: 1.03, 1.19) for a (p75/p25)-factor increase in 1-year mean BC, corresponding estimates for PM_2.5, PM₁₀ and NO₂ were 1.10 (95% CI: 1.01, 1.19), 1.10 (95% CI: 1.01, 1.20) and 1.08 (95% CI: 1.00, 1.16). Lymphocyte count increased with a factor 1.05 (95% CI: 1.01, 1.10) for a (p75/p25)-factor increase in 1-year mean NO₂. Similar results were observed for 3-month mean exposures. Results were robust to adjustment for recent air pollution exposure. In girls, air pollutants were not associated with HCC or differential leucocyte count. Residential traffic noise level was not associated with HCC or leucocyte counts in boys nor girls.

CONCLUSIONS

Long-term residential exposure to air pollutants was positively associated with chronic endocrine stress and inflammation in adolescent boys, not in girls. This study may contribute to a better understanding of the early pathophysiological changes that may underlie adverse health effects of air pollution exposure in adolescents.

Elevated White Blood Cell Count Resultant Atherogenesis is Associated With Panoramic-Imaged Carotid Plaque

PURPOSE

Atherosclerotic plaques develop as a result of a low-grade, chronic, systemic inflammatory response to the injury of endothelial cells arising from lipid deposition within the intima. Increased white blood cell count (WBCC) is both a validated "biologic marker" of the extent of this inflammatory process and a key participant in the development of subsequent atherosclerotic ischemic heart disease manifesting as myocardial infarction. We sought to determine if calcified carotid artery plaque (CCAP) on a panoramic image (PI), also a validated risk indicator of future myocardial infarction, is associated with increased WBCC.

PATIENTS AND METHODS

We retrospectively evaluated the PI and medical records of White male military veterans aged 55 years and older treated by a VA dental service. Established were 2 cohorts of patients, 50 having plaques (CCAP+) and 50 without plaques (CCAP-). Predictor variable was CCAP+; outcome variable was WBCC. Bootstrapping analysis determined the differences in mean WBCCs between groups. Statistical significance set at ≤ 0.05.

RESULTS

The study group, (mean age 74; range 59 to 91 years) demonstrated a mean WBCC of 8,062 per mm³. The control group, (mean age 72 range; 57 to 94) evidenced a mean WBCC of 7,058 per mm³. Bootstrapping analysis of WBCC values demonstrated a significant (P = .012) difference (95% confidence interval of difference of mean, -806, 742; observed effect size, 1004) between groups.

CONCLUSIONS

The presence of CCAP demonstrated on PIs of older Caucasian men is associated with elevated WBCC. Concomitant presence of CCAP on PI and increased WBCC (≥7,800 per mm³) amplifies need for medical consultation before intravenous anesthesia and maxillofacial surgical procedures.

Cigarette Smoke Exposure in Mice using a Whole-Body Inhalation System

Close to 14% of adults in the United States were reported to smoke cigarettes in 2018. The effects of cigarette smoke (CS) on lungs and cardiovascular diseases have been widely studied, however, the impact of CS in other tissues and organs such as blood and bone marrow remain incompletely defined. Finding the appropriate system to study the effects of CS in rodents can be prohibitively expensive and require the purchase of commercially available systems. Thus, we set out to build an affordable, reliable, and versatile system to study the pathologic effects of CS in mice. This whole-body inhalation exposure system (WBIS) set-up mimics the breathing and puffing of cigarettes by alternating exposure to CS and clean air. Here we show that this do-it-yourself (DIY) system induces airway inflammation and lung emphysema in mice after 4-months of cigarette smoke exposure. The effects of whole-body inhalation (WBI) of CS on hematopoietic stem and progenitor cells (HSPCs) in the bone marrow using this apparatus are also shown.

The mediating role of inflammation in the association between cigarette smoking and intima-media thickness: The Guangzhou biobank cohort study

Cigarette smoking is associated with thicker carotid intima-media thickness (IMT), probably partly through inflammatory pathways. However, to what extent does inflammation mediate the smoking-carotid atherosclerosis association is unclear. We investigated the mediating effect of inflammation on the association between cigarette smoking and carotid IMT, and quantified the respective contributions of inflammatory markers to this association.A total of 1752 participants from Guangzhou Biobank Cohort Study-Cardiovascular Disease Sub-cohort (GBCS-CVD) were included. Using causal mediation analysis under the counterfactual framework, we decomposed total effects of cigarette smoking on IMT into indirect effects (through inflammatory response) and direct effects (not through inflammatory response).After adjusting for traditional risk factors, the indirect effects of per 10/L increment in leukocyte and granulocyte, per mg/L increment in high-sensitivity C-reactive protein (hs-CRP), and per mg/dL increment in fibrinogen on carotid IMT was 0.0028 mm (95% confidence interval [CI], 0.0011-0.0047), 0.0019 mm (95% CI, 0.0006-0.0034), 0.0017 mm (95% CI, 0.0006-0.003), and 0.001 mm (95% CI, 0.0001-0.0021), respectively. No evidence for a mediating role of lymphocyte was found. The proportion of the smoking-IMT association mediated by leukocyte, granulocyte, hs-CRP, and fibrinogen was 12.57% (95% CI, 8.50%-22.11%), 8.50% (95% CI, 5.76%-15.09%), 7.64% (95% CI, 5.20%-13.79%), and 4.48% (95% CI, 3.04%-8.03%), respectively. Restricting data analysis to men showed similar results.The effects of cigarette smoking on IMT were partly mediated by leukocyte, hs-CRP, and fibrinogen. The mediating role of leukocyte was likely mainly driven by higher granulocyte.

White Blood Cell Count and Risk of Incident Lung Cancer in the UK Biobank

Background

The contribution of measurable immunological and inflammatory parameters to lung cancer development remains unclear, particularly among never smokers. We investigated the relationship between total and differential white blood cell (WBC) counts and incident lung cancer risk overall and among subgroups defined by smoking status and sex in the United Kingdom (UK).

Methods

We evaluated 424 407 adults aged 37-73 years from the UK Biobank. Questionnaires, physical measurements, and blood were administered and collected at baseline in 2006-2010. Complete blood cell counts were measured using standard methods. Lung cancer diagnoses and histological classifications were obtained from cancer registries. Multivariable Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence intervals of incident lung cancer in relation to quartiles (Q) of total WBC and subtype-specific counts, with Q1 as the reference.

Results

There were 1493 incident cases diagnosed over an average 7-year follow-up. Overall, the highest quartile of total WBC count was statistically significantly associated with elevated lung cancer risk (HR_Q4 = 1.67, 95% CI = 1.41 to 1.98). Among women, increased risks were found in current smokers (n _cases / n = 244 / 19 464, HR_Q4 = 2.15, 95% CI = 1.46 to 3.16), former smokers (n _cases / n = 280 / 69 198, HR_Q4 = 1.75, 95% CI = 1.24 to 2.47), and never smokers without environmental tobacco smoke exposure (n_cases / n = 108 / 111 294, HR_Q4 = 1.93, 95% CI = 1.11 to 3.35). Among men, stronger associations were identified in current smokers (n_{case s} / n = 329 / 22 934, HR_Q4 = 2.95, 95% CI = 2.04 to 4.26) and former smokers (n_{c ases} / n = 358/71 616, HR_Q4 = 2.38, 95% CI = 1.74 to 3.27) but not in never smokers. Findings were similar for lung adenocarcinoma and squamous cell carcinoma and were driven primarily by elevated neutrophil fractions.

Conclusions

Elevated WBCs could potentially be one of many important markers for increased lung cancer risk, especially among never-smoking women and ever-smoking men.

White cell counts in relation to mortality in a general population of cohort study in the Netherlands: a mediating effect or not?

BACKGROUND

White cell count (WCC) is a clinical marker of inflammation. Data are limited regarding the association of total and differential WCC with risk of mortality, and its role related with smoking and body mass index (BMI).

METHODS

A total of 14 433 participants (4150 men; 10 283 women; average age 47.3±11.8 years) from the Dutch European Prospective Investigation into Cancer and Nutrition-Netherlands cohort were included. The associations between prediagnostic total WCC and its subtypes and risk of all-cause, cancer and cardiovascular disease (CVD) mortality were assessed. The role of WCC related with smoking and BMI on mortality was further explored. Multivariate Cox regression models were performed to estimate the HR and 95% CI.

RESULTS

After an average follow-up of 15.8 years, a total of 936 death cases were identified (466 cancer; 179 CVD; 291 other causes). Statistically significant graded associations between total WCC, and counts of lymphocytes, monocytes, neutrophils and eosinophils and risk of total mortality were observed. These associations were more apparent in current smokers. Strong associations for all-cause mortality or cancer mortality were observed in subjects with BMI ≥25 kg/m², ever smoking and elevated WCC (HR 3.92, 95% CI 2.76 to 5.57; HR 3.93, 95% CI 2.30 to 6.72). WCC partly mediated the associations between smoking or BMI and all-cause mortality.

CONCLUSIONS

Prediagnostic WCC and its subtypes are associated with all-cause, cancer and CVD mortality risk. It may play a partially mediate role on the association between smoking or obesity and mortality.

Meta-MultiSKAT: Multiple phenotype meta-analysis for region-based association test

The power of genetic association analyses can be increased by jointly meta-analyzing multiple correlated phenotypes. Here, we develop a meta-analysis framework, Meta-MultiSKAT, that uses summary statistics to test for association between multiple continuous phenotypes and variants in a region of interest. Our approach models the heterogeneity of effects between studies through a kernel matrix and performs a variance component test for association. Using a genotype kernel, our approach can test for rare-variants and the combined effects of both common and rare-variants. To achieve robust power, within Meta-MultiSKAT, we developed fast and accurate omnibus tests combining different models of genetic effects, functional genomic annotations, multiple correlated phenotypes, and heterogeneity across studies. In addition, Meta-MultiSKAT accommodates situations where studies do not share exactly the same set of phenotypes or have differing correlation patterns among the phenotypes. Simulation studies confirm that Meta-MultiSKAT can maintain the type-I error rate at the exome-wide level of 2.5 × 10^-6 . Further simulations under different models of association show that Meta-MultiSKAT can improve the power of detection from 23% to 38% on average over single phenotype-based meta-analysis approaches. We demonstrate the utility and improved power of Meta-MultiSKAT in the meta-analyses of four white blood cell subtype traits from the Michigan Genomics Initiative (MGI) and SardiNIA studies.

Extreme-value sampling design is cost-beneficial only with a valid statistical approach for exposure-secondary outcome association analyses

In epidemiology cohort studies, exposure data are collected in sub-studies based on a primary outcome (PO) of interest, as with the extreme-value sampling design (EVSD), to investigate their correlation. Secondary outcomes (SOs) data are also readily available, enabling researchers to assess the correlations between the exposure and the SOs. However, when the EVSD is used, the data for SOs are not representative samples of a general population; thus, many commonly used statistical methods, such as the generalized linear model (GLM), are not valid. A prospective likelihood method has been developed to associate SOs with single-nucleotide polymorphisms under an extreme phenotype sequencing design. In this paper, we describe the application of the prospective likelihood method (ST_EVSD) to exposure-SO association analysis under an EVSD. We undertook extensive simulations to assess the performance of the ST_EVSD method in associating binary and continuous exposures with SOs, comparing it to the simple GLM method that ignores the EVSD. To demonstrate the cost-benefit of the ST_EVSD method, we also mimicked the design of two new retrospective studies, as would be done in actual practice, based on the PO of interest, which was the same as the SO in the EVSD study. We then analyzed these data by using the GLM method and compared its power to that of the ST_EVSD method. We demonstrated the usefulness of the ST_EVSD method by applying it to a benign ethnic neutropenia dataset. Our results indicate that the ST_EVSD method can control type I error well, whereas the GLM method cannot do so owing to its ignorance of EVSD, and that the ST_EVSD method is cost-effective because it has statistical power similar to that of two new retrospective studies that require collecting new exposure data for selected individuals.

Albumin, white blood cell count, and body mass index improve discrimination of mortality in HIV-positive individuals

OBJECTIVE

Despite viral suppression and immune response on antiretroviral therapy, people with HIV infection experience excess mortality compared with uninfected individuals. The Veterans Aging Cohort Study (VACS) Index incorporates clinical biomarkers of general health with age, CD4 cell count, and HIV-1 RNA to discriminate mortality risk in a variety of HIV-positive populations. We asked whether additional biomarkers further enhance discrimination.

DESIGN AND METHODS

Using patients from VACS for development and from the Antiretroviral Therapy Cohort Collaboration (ART-CC) for validation, we obtained laboratory values from a randomly selected visit from 2000 to 2014, at least 1 year after antiretroviral therapy initiation. Patients were followed for 5-year, all-cause mortality through September 2016. We fitted Cox models with established predictors and added new predictors based on model fit and Harrell's c-statistic. We converted all variables to continuous functional forms and selected the best model (VACS Index 2.0) for validation in ART-CC patients. We compared discrimination using c-statistics and Kaplan-Meier plots.

RESULTS

Among 28 390 VACS patients and 12 109 ART-CC patients, 7293 and 722 died, respectively. Nadir CD4, CD8, and CD4 : CD8 ratio did not improve discrimination. Addition of albumin, white blood count, and BMI, improved c-statistics in VACS from 0.776 to 0.805 and in ART-CC from 0.800 to 0.831. Results were robust in all nine ART-CC cohorts, all lengths of follow-up and all subgroups.

CONCLUSION

VACS Index 2.0, adding albumin, white blood count, and BMI to version 1.0 and using continuous variables, provides improved discrimination and is highly transportable to external settings.

Relation of inflammatory markers with symptoms of psychotic disorders: a large cohort study

AIMS

Immunological mechanisms may play a role in symptomatology of patients with a psychotic disorder. Besides metabolic problems and medication use, inflammatory processes that may occur due to the disorder may cause increased inflammatory markers and concurrent psychiatric symptoms. The aim of this study is to investigate whether levels of C-reactive protein (CRP) and white blood cell count (WBC) are related to positive and negative symptoms of psychotic disorders, and whether age, gender, duration of illness, smoking behavior, haloperidol equivalents, mediation use, body mass, and metabolic syndrome affect this relation.

METHODS

CRP and WBC values of 2123 patients with a psychotic disorder were related to positive and negative symptoms measured with a psychiatric interview. CRP was analyzed by survival analysis accounting for detection limit and WBC by linear mixed model analysis. In case of a significant association, the confounding factors were added to the model.

RESULTS

Both WBC and CRP were related to both positive and negative symptoms, even after correction for age, gender, smoking, use of medication and metabolic problems. Of the covariates, gender, metabolic problems, smoking and statins also showed a strong association with inflammatory markers.

CONCLUSIONS

This study in a large patient-group confirmed that inflammatory markers are related to psychotic disorders, particularly negative symptoms. Future studies could use more precise measures of inflammatory markers and measure symptomatic state at specific moments in illness progression.

Marijuana Use Impacts Midlife Cardiovascular Events in HIV-Infected Men

BACKGROUND

Marijuana use is prevalent among persons infected with human immunodeficiency virus (HIV), but its long-term effects on HIV disease progression and comorbidities are unknown.

METHODS

In this prospective study of 558 HIV-infected men enrolled in the Multicenter AIDS Cohort Study between 1990 and 2010, there were 182 HIV seroconverters and 376 with viral suppression on combination antiretroviral therapy (ART). Associations between heavy marijuana use and HIV disease markers or white blood cell (WBC) count were examined using mixed-effects and linear regression models. Effects of marijuana use on cardiovascular (CV) events and other endpoints were estimated using Kaplan-Meier and logistic regression analyses.

RESULTS

The median baseline age of participants was 41, 66% were white, 79% had education >12 years, and 20% reported heavy marijuana use at ≥50% of biannual visits during follow-up. Long-term heavy marijuana use showed no significant associations with viral load, CD4 counts, AIDS, cancer, or mortality in both cohorts but was independently associated with increased CV events between ages 40-60 after adjusting for age, tobacco smoking, viral load, and traditional risk factors (odds ratio [OR], 2.5; 95% confidence interval [CI] 1.3, 5.1). Marijuana and tobacco use were each independently associated with higher WBC counts in adjusted models (P < .01); the highest quartile of WBC counts (≥6500 cells/µL) was associated with increased CV events (OR 4.3; 95% CI, 1.5, 12.9).

CONCLUSIONS

Heavy marijuana use is a risk factor for CV disease in HIV-infected men ages 40-60, independent of tobacco smoking and traditional risk factors.

Using a multivariate model to assess the interactive effects of demographics and lifestyle on the hematological profile

AIM

To assess the extent to which a multivariate approach to modeling interrelated hematological indices provides more informative results than the traditional approach of modeling each index separately.

MATERIALS & METHODS

The effects of demographics and lifestyle on ten hematological indices collected from a Dutch population-based sample (n = 3278) were studied, jointly using multivariate distance matrix regression and separately using linear regression.

RESULTS

The multivariate approach highlighted the main effects of all predictors and several interactions; the traditional approach highlighted only main effects.

CONCLUSION

The multivariate approach provides more power than traditional methods to detect effects on interrelated biomarkers, suggesting that its use in future research may help identify subgroups that benefit from different treatment or prevention measures.

Does occupational exposure to formaldehyde cause hematotoxicity and leukemia-specific chromosome changes in cultured myeloid progenitor cells?

Several cross-sectional studies of a single population of workers exposed to formaldehyde at one of two factories using or producing formaldehyde-melamine resins in China have concluded that formaldehyde exposure induces damage to hematopoietic cells that originate in the bone marrow. Moreover, the investigators interpret observed differences between groups as evidence that formaldehyde induces myeloid leukemias, although the mechanisms for inducing these diseases are not obvious and recently published scientific findings do not support causation. Our objective was to evaluate hematological parameters and aneuploidy in relation to quantitative exposure measures of formaldehyde. We obtained the study data for the original study (Zhang et al. 2010 ) and performed linear regression analyses. Results showed that differences in white blood cell, granulocyte, platelet, and red blood cell counts are not exposure dependent. Among formaldehyde-exposed workers, no association was observed between individual average formaldehyde exposure estimates and frequency of aneuploidy, suggested by the original study authors to be indicators of myeloid leukemia risk.

Night shift work and inflammatory markers in male workers aged 20-39 in a display manufacturing company

Background

This study aimed to determine the association between shift work and inflammatory markers, which are independent risk factors of cardiovascular diseases, in male manual workers at a display manufacturing company.

Methods

This study was conducted between June 1 and July 31, 2015 on 244 male manual workers aged 20–39 years old at a display manufacturing company and investigated age, marital status, education level, alcohol consumption habit, smoking habit, regular exercise habit, sleep duration, sleep debt, sleep insufficiency, past medical history, current and past shift work experience, duration of shift work, and weekly work hours through face-to-face interviews using structured questionnaires and performed blood tests. Study participants were divided into daytime, former shift, and current shift workers based on the work schedule. Chi-square tests and one-way analyses of variance were performed to compare inflammatory markers and cardiovascular disease risk factors, and analyses of covariance were conducted after adjusting for variables potentially affecting inflammatory markers.

Results

High-sensitivity C-reactive protein (hs-CRP; mean ± standard deviation) levels in daytime, former shift, and current shift workers were 0.65 ± 0.43, 0.75 ± 0.43, and 0.86 ± 0.72 mg/L, respectively (p = 0.029). The leukocyte count (mean ± standard deviation) was 5,556 ± 1,123, 6,210 ± 1,366, and 6,530 ± 1,216 cells/μL, respectively (p < 0.001). Both hs-CRP level and leukocyte count were significantly higher in current shift workers than in daytime workers, and leukocyte count was higher in former shift workers than in daytime workers. After adjusting for variables potentially affecting inflammatory markers, hs-CRP levels (adjusted mean ± standard deviation) in daytime and current shift workers were 0.59 ± 0.06 and 0.92 ± 0.07 mg/L, respectively (p = 0.002). The leukocyte count (adjusted mean ± standard deviation) was 5,557 ± 124 and 6,498 ± 144 cells/μL, respectively (p < 0.001).

Conclusions

A significant association between shift work and increases in inflammatory markers was confirmed. Because chronic low-grade inflammation plays an important role in the development of cardiovascular diseases, regular follow-up of inflammatory markers as a marker of cardiovascular diseases in shift workers may serve as an early indicator in predicting the effects of shift work on health.

Current cigarette smoking is a reversible cause of elevated white blood cell count: Cross-sectional and longitudinal studies

While cigarette smoking is a well-recognized cause of elevated white blood cell (WBC) count, studies on longitudinal effect of smoking cessation on WBC count are limited. We attempted to determine causal relationships between smoking and elevated WBC count by retrospective cross-sectional study consisting of 37,972 healthy Japanese adults who had a health check-up between April 1, 2008 and March 31, 2009 and longitudinal study involving 1730 current smokers who had more than four consecutive annual health check-ups between April 1, 2007 and March 31, 2012. In the cross-sectional study, younger age, male gender, increased body mass index, no alcohol habit, current smoking, and elevated C-reactive protein level were associated with elevated WBC count. Among these factors, current smoking had the most significant association with elevated WBC count. In subgroup analyses by WBC differentials, smoking was significantly associated with elevated counts of neutrophils, lymphocytes, monocytes, eosinophils, and basophils. Ex-smoking was not associated with elevated WBC count. In the longitudinal study, both WBC and neutrophil counts decreased significantly in one year after smoking cessation and remained down-regulated for longer than next two years. There was no significant change in either WBC or neutrophil count in those who continued smoking. These findings clearly demonstrated that current smoking is strongly associated with elevated WBC count and smoking cessation leads to recovery of WBC count in one year, which is maintained for longer than subsequent two years. Thus, current smoking is a significant and reversible cause of elevated WBC count in healthy adults.

The amount and duration of smoking is associated with aggravation of hormone and biochemical profile in women with PCOS

We investigated the association between the amount and duration of smoking on biochemical, clinical parameters and the ovarian morphology in women with polycystic ovary syndrome (PCOS). That was a retrospective study. These women were divided into two groups, non-smokers (217) and smokers (92). The amount of cigarettes and duration of smoking was measured in pack-years. Both groups underwent clinical evaluation, biochemical and hormone analysis, transvaginal ultrasound and oral glucose tolerance tests (OGTT). The mean value of the number of cigarettes was 14.8 (±8.8) and the median value of pack-years in the smokers group was 4.0 (1.5-7.5). Smokers group has significantly higher free testosterone (F-T), 17-hydroxyprogesterone (17-OHP), delta 4 androstenedione (Δ4-A), T4, low-density lipoprotein (LDL), and white blood cells (WBC). During correlation of all the above parameters and pack-years, there has been significant positive correlation in F-T and Δ4-A. The participants with more pack-years showed statistically higher values of F-T and Δ4-A. There was also a significant positive correlation between total cholesterol, triglycerides, WBC and pack-years of the participants. Prolactin (PRL) has been inversely associated with pack-years. We concluded that the increase of pack-years aggravated lipid profile, WBC and decreased PRL levels, in PCOS patients.

Do circulating blood cell types correlate with modifiable risk factors and outcomes in patients with acute coronary syndrome (ACS)?

AIMS

Atherosclerosis is an inflammatory process with different cardiovascular risk factors (CVRFs) contributing to its pathogenesis. We aimed to evaluate the specific relationship between circulating blood leukocytes, troponin I and CVRFs.

METHODS

We prospectively enrolled 959 patients with evidence of acute coronary syndrome either in form of unstable angina or STEMI or NSTEMI. Details demographic characteristics, CVRF and biochemical parameters such as total white blood cells (WBC), neutrophil, lymphocytes, platelet, neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), and troponin I were collected.

RESULTS

The results indicated that patients having either hypertension, diabetes or smoking habit had significantly higher levels of total WBC (p=0.013), neutrophil (p=0.029), NLR (p=0.029) and PLR (p=0.009). The level of troponin I was unaffected by these risk factors. Significant association of hypertension was found with total WBC (p=0.0392), lymphocytes (p=0.0384) and PLR (p=0.0027), whereas in diabetes and females all other leukocyte subtypes were significantly altered except for platelet and troponin I. Smokers had higher level of total WBC count (p=0.0033) and PLR (p=0.0464). No relationship between CVRFs and leukocytes was observed in males. The age independent effect was observed with PLR, whereas association with total WBC, lymphocytes, NLR, platelet was specific in older population. In younger patients NLR (p=0.0453) is more likely to be elevated. Mortality was significantly associated with changes in the leukocytes but not with the CVRF presence.

CONCLUSION

We demonstrate that the neutrophils, lymphocytes and total WBC along with its ratios predict mortality and are more likely to be elevated in presence of CVRFs.

Relationship between white blood cells and hypertension in Chinese adults: the Cardiometabolic Risk in Chinese (CRC) study

Increased blood pressure was associated with increased white blood cell count (adjusted p < 0.001) in a community-based health examination survey of adults in China (n = 39 282; aged 18-93 years). Adjusted odds ratios (95% confidence intervals) for hypertension across white blood cell count quintiles were 1.00, 0.99 (0.89-1.09), 1.11 (1.01-1.22), 1.09 (0.99-1.20), and 1.19 (1.08-1.31) (p for trend < 0.001). Body mass index and white blood cell count had an additive effect on systolic blood pressure (p for interaction = 0.047). Therefore, white blood cell count could independently predict hypertension in Chinese adults.

Prenatal exposure to maternal smoking and offspring DNA methylation across the lifecourse: findings from the Avon Longitudinal Study of Parents and Children (ALSPAC)

Maternal smoking during pregnancy has been found to influence newborn DNA methylation in genes involved in fundamental developmental processes. It is pertinent to understand the degree to which the offspring methylome is sensitive to the intensity and duration of prenatal smoking. An investigation of the persistence of offspring methylation associated with maternal smoking and the relative roles of the intrauterine and postnatal environment is also warranted. In the Avon Longitudinal Study of Parents and Children, we investigated associations between prenatal exposure to maternal smoking and offspring DNA methylation at multiple time points in approximately 800 mother–offspring pairs. In cord blood, methylation at 15 CpG sites in seven gene regions (AHRR, MYO1G, GFI1, CYP1A1, CNTNAP2, KLF13 and ATP9A) was associated with maternal smoking, and a dose-dependent response was observed in relation to smoking duration and intensity. Longitudinal analysis of blood DNA methylation in serial samples at birth, age 7 and 17 years demonstrated that some CpG sites showed reversibility of methylation (GFI1, KLF13 and ATP9A), whereas others showed persistently perturbed patterns (AHRR, MYO1G, CYP1A1 and CNTNAP2). Of those showing persistence, we explored the effect of postnatal smoke exposure and found that the major contribution to altered methylation was attributed to a critical window of in utero exposure. A comparison of paternal and maternal smoking and offspring methylation showed consistently stronger maternal associations, providing further evidence for causal intrauterine mechanisms. These findings emphasize the sensitivity of the methylome to maternal smoking during early development and the long-term impact of such exposure.

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

Background:

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

Materials and Methods:

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

Results:

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

Conclusion:

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

A Biochip with a 3D microfluidic architecture for trapping white blood cells

We present a microfluidic biochip for trapping single white blood cells (WBCs). The novel biochip, microfabricated using standard surface micromachining processes, consists of an array of precisely engineered microholes that confine single cells in a tight, three dimensional space and mechanically immobilize them. A high (> 87%) trapping efficiency was achieved when WBC-containing samples were delivered to the biochip at the optimal pressure of 3 psi. The biochip can efficiently trap up to 7,500 cells, maintaining a high trapping efficiency even when the number of cells is extremely low (~200 cells). We believe that the developed biochip can be used as a standalone unit in a biology/clinical lab for trapping WBCs as well as other cell types and imaging them using a standard fluorescent microscope at the single cell level. Furthermore, it can be integrated with other miniaturized optical modules to construct a portable platform for counting a wide variety of cells and therefore it can be an excellent tool for monitoring human diseases at the point-of-care.

Range-reference determination of lymphocyte subsets in Moroccan blood donors

BACKGROUND

Information on lymphocyte populations (T, B, and Natural killer cells) and subpopulations (CD4 and CD8) in Morocco is scarce if not inexistent.

OBJECTIVE

To establish a reference value of these cells in 242 Moroccan young adult blood donors by flow cytometry.

RESULTS

Smokers had significantly higher total leukocyte count (p < 0.001), total lymphocyte count (p < 0.0001) and higher CD3+CD4+ cells (p < 0.0001). The percentage of CD3-CD56+ subsets was affected by smoking (p < 0.01). Our analysis positively correlate with previous observations of an increase of absolute CD4+ T cells, with no changes in other lymphocyte subset cells in smokers. The lymphocyte subpopulation distributions for all antigens were found to be similar to those reported in Saudi and Italian adults, while higher levels were reported for the same gender in other countries, especially Ghana and Kuwait.

CONCLUSION

The international classification standards of the HIV-infected subjects according to their rates of CD4 are applicable to the present study's population.

Neutrophil-lymphocyte ratio as a predictor of major adverse cardiac events among diabetic population: a 4-year follow-up study

The neutrophil-lymphocyte ratio (NLR) is an inflammatory marker of major adverse cardiac events (MACEs) in both acute coronary syndromes and stable coronary artery disease. The use of NLR as a predictive tool for MACEs among diabetic patients has not been elucidated. An observational study included 338 diabetic patients followed at our clinic between 2007 and 2011. Patients were arranged into equal tertiles according to the 2007 NLR. The MACEs included acute myocardial infarction, coronary revascularization, and mortality. The lowest NLR tertile (NLR < 1.6) had fewer MACEs compared with the highest NLR tertile (NLR > 2.36; MACEs were 6 of 113 patients vs 24 of 112 patients, respectively; P < .0001). In a multivariate model, the adjusted hazard ratio of third NLR tertile compared with first NLR tertile was 2.8 (95% confidence interval 1.12-6.98, P = .027). The NLR is a significant independent predictor of MACEs in diabetic patients. Further studies with larger numbers are needed.

Impulsivity-related traits are associated with higher white blood cell counts

A chronically elevated white blood cell (WBC) count is a risk factor for morbidity and mortality. The present research tests whether facets of impulsivity-impulsiveness, excitement-seeking, self-discipline, and deliberation-are associated with chronically elevated WBC counts. Community-dwelling participants (N = 5,652) from Sardinia, Italy, completed a standard personality questionnaire and provided blood samples concurrently and again 3 years later. Higher scores on impulsivity, in particular impulsiveness and excitement-seeking, were related to higher total WBC counts and higher lymphocyte counts at both time points. Impulsiveness was a predictor of chronic inflammation: for every standard deviation difference in this trait, there was an almost 25% higher risk of elevated WBC counts at both time points (OR = 1.23, 95% CI = 1.10-1.38). These associations were mediated, in part, by smoking and body mass index. The findings demonstrate that links between psychological processes and immunity are not limited to acute stressors; stable personality dispositions are associated with a chronic inflammatory state.

Recent cigarette smoking and HIV disease progression: no evidence of an association

The association between smoking and HIV disease progression has been examined in several studies; however, findings have been inconsistent. We examined the effect of recent cigarette smoking on CD4(+) T cell count/µl (CD4 count) and HIV RNA concentration (HIV viral load (VL)) among two HIV-infected cohorts with alcohol problems in Massachusetts in the periods 1997-2001 and 2001-2006 using a prospective cohort design and linear mixed models. Smoking groups were defined as: minimal or non-smokers, light smokers, moderate smokers, and heavy smokers. Age, alcohol use, injection drug use, depressive symptoms, gender, annual income, and antiretroviral therapy adherence were considered as potential confounders. Among 462 subjects, no significant differences in CD4 count or VL were found between smoking groups. Using minimal or non-smokers as the reference group, the adjusted mean differences in CD4 count were: 8.2 (95% confidence interval (CI): -17.4, 33.8) for heavy smokers; -0.1 (95% CI: -25.4, 5.1) for moderate smokers; and -2.6 (95% CI: -28.3, 3.0) for light smokers. For log10 VL, the adjusted differences were: 0.03 (95% CI: -0.12, 0.17) for heavy smokers; -0.06 (95% CI: -0.20, 0.08) for moderate smokers; and 0.14 (95% CI -0.01, 0.28) for light smokers. This study did not find an association between smoking cigarettes and HIV disease progression as measured by CD4 cell count and VL.

Lung function and respiratory symptoms in a 1-year randomized smoking cessation trial of varenicline in COPD patients

There are few data concerning changes in lung function and respiratory symptoms in smokers with chronic obstructive pulmonary disease (COPD) weeks to months after quitting smoking. We examined serial changes in spirometry and Clinical COPD Questionnaire (CCQ) scores (measuring respiratory symptoms and health-related quality of life) in COPD participants by smoking status during a smoking cessation trial. In this randomized, double-blind trial, smokers with mild-to-moderate COPD were treated with varenicline 1 mg b.i.d. or placebo for 12 weeks and followed to Week 52. Primary endpoints of abstinence were previously reported. Secondary endpoints were mean changes from baseline in post-bronchodilator forced expired volume in 1 s (FEV(1)) and CCQ scores. Change from baseline in post-bronchodilator FEV(1) was significantly improved in continuous abstainers (121.8 mL) vs. continuous smokers (37.9 mL) at Week 12 (P = 0.0069), but not at Weeks 24 or 52. Mean change from baseline at Week 12 in CCQ Total Score was significantly better in continuous abstainers (-1.04) vs. continuous smokers (-0.53; P < 0.0001): this improvement was sustained at Weeks 24 and 52. In a 1-year cessation trial of smokers with COPD, continuous abstinence compared with continuous smoking significantly improved post-bronchodilator FEV(1) at Week 12 (although the difference narrowed subsequently) and CCQ Total Scores at Week 12, with sustained improvement thereafter. (

TRIAL REGISTRY

http://www.clinicaltrials.gov; trial identifier: NCT00285012).

Longitudinal trends of total white blood cell and differential white blood cell counts of atomic bomb survivors

In studying the late health effects of atomic-bomb (A-bomb) survivors, earlier findings were that white blood cell (WBC) count increased with radiation dose in cross-sectional studies. However, a persistent effect of radiation on WBC count and other risk factors has yet to be confirmed. The objectives of the present study were 1) to examine the longitudinal relationship between A-bomb radiation dose and WBC and differential WBC counts among A-bomb survivors and 2) to investigate the potential confounding risk factors (such as age at exposure and smoking status) as well as modification of the radiation dose-response. A total of 7,562 A-bomb survivors in Hiroshima and Nagasaki were included in this study from 1964-2004. A linear mixed model was applied using the repeated WBC measurements. During the study period, a secular downward trend of WBC count was observed. Radiation exposure was a significant risk factor for elevated WBC and differential WBC counts over time. A significant increase of WBC counts among survivors with high radiation dose (> 2 Gy) was detected in men exposed below the age of 20 and in women regardless of age at exposure. Effects on WBC of low dose radiation remain unclear, however. Cigarette smoking produced the most pronounced effect on WBC counts and its impact was much larger than that of radiation exposure.

No evidence of a change in HIV-1 virulence since 1996 in France

OBJECTIVE

We investigated temporal trends in the CD4 cell count and in plasma HIV RNA and total HIV DNA levels measured at the time of primary HIV infection, as proxies for HIV-1 virulence, taking changes in patient characteristics into account.

DESIGN

We studied 903 patients enrolled during primary HIV infection in the French multicenter ANRS PRIMO cohort from 1996 to 2007.

METHODS

Associations between the year of primary HIV infection and the values of the three markers were tested with regression models. The year of primary HIV infection was first introduced as a restricted cubic splines function in a regression model in order to explore the shape of the associations, and then as a continuous/categorical variable. The following confounders were considered in multiple regression analysis: time since infection and age (introduced as restricted cubic spline functions), sex, place of birth (Africa vs. others), symptomatic primary HIV infection, smoking, and virus-related factors (subtype B vs. non-B, and drug resistance mutations).

RESULTS

Multivariate analysis showed no temporal trends in the CD4 cell count (square-root) or in HIV-1 RNA and DNA levels (log10) measured at the time of primary HIV infection. We observed the well described associations between the prognostic markers and the time since infection, sex, symptomatic primary HIV infection, and smoking.

CONCLUSION

The CD4 cell count and HIV RNA and DNA levels measured at the time of primary HIV-1 infection remained stable across 12 consecutive years (1996-2007) in the ANRS PRIMO cohort, suggesting no major change in virulence, after taking into account changes in patient characteristics.

Homeostatic regulation of blood neutrophil counts

Blood neutrophil counts are determined by the differentiation and proliferation of precursor cells, the release of mature neutrophils from the bone marrow, margination, trafficking and transmigration through the endothelial lining, neutrophil apoptosis, and uptake by phagocytes. This brief review summarizes the regulation of blood neutrophil counts, which is in part controlled by G-CSF, IL-17, and IL-23. Neutrophils are retained in the bone marrow through interaction of CXCL12 with its receptor CXCR4. The relevance of this mechanism is illustrated by rare diseases in which disrupting the desensitization of CXCR4 results in failure to release mature neutrophils from bone marrow. Although blood neutrophil numbers in inbred mouse strains and individual human subjects are tightly controlled, their large variation among outbred populations suggests genetic factors. One example is benign ethnic neutropenia, which is found in some African Americans. Reduced and elevated neutrophil counts, even within the normal range, are associated with excess all-cause mortality.

Does smoking status affect the association between baseline white blood cell count and in-hospital mortality of patients presented with Acute Coronary Syndrome? The Greek study of Acute Coronary Syndromes (GREECS)

OBJECTIVES

In this work, we sought to investigate whether smoking status modifies the effect of white blood cell count (WBC) on in-hospital mortality of patients presented with acute coronary syndrome (ACS).

METHODS

A sample of 6 hospitals located in Greek urban and rural regions was selected. We recorded almost all consecutive patients due to ACS, from October 2003 to September 2004 (2172 patients).

RESULTS

The mean (standard deviation) WBC count was 9.14 (3.16) cells/dL. The in-hospital mortality rate was higher in patients of upper tertile compared to those of lower tertile of WBC (p<0.05). The interaction between smoking status and WBC count revealed that smoking status modifies the effect of WBC count on mortality (p for interaction=0.004). Thus, stratified analysis showed that the WBC count is an independent predictor of in-hospital mortality only among former and current smokers.

CONCLUSIONS

We demonstrated that the association between WBC count and mortality modified by smoking status and that WBC count is a predictor of mortality only among former and current smokers.

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

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

Variation in the WBC differential count and other factors associated with reporting of herpes labialis: A population-based study of adults

Reactivation of latent herpes virus has been linked to triggers of mild immunosupression, such as stress or UV-exposure. Despite having predictive value in severe immunodeficiency, the white blood cell (WBC) differential count has not been examined in relation to risk of herpes reactivation in population studies. The WBC differential count and other risk factors for herpes labialis were examined in 5687 adults (ages 18-64) from the Third National Health and Nutrition Examination Survey, who had WBC 3.5-11 x 10(6) cells mL(-1) and reported no acute infections in the past month. The association between self-reported herpes labialis in the past year and the WBC differential count was modeled, adjusting for age, sex, race/ethnicity, education, smoking, upper respiratory infections (URI), and HSV-1 antibodies. Herpes labialis was significantly associated with white race/ethnicity, being a nonsmoker, and frequent URI. Compared with the highest quartile, being in the lowest quartile of granulocytes was associated with herpes labialis, adjusted odds ratio=1.82 (95% confidence interval 1.20, 2.28). At the same time, there was a trend towards an inverse association of lower lymphocyte count and herpes labialis. These findings suggest that moderate differences in the WBC differential count are related to reactivation of HSV-1. Prospective studies may help to show whether such differences indicate susceptibility to loss of latency or represent a consequence of reactivated infection.

Relationship between smoking, white blood cell count and metabolic syndrome in Japanese women

We found that cigarette smoking increased white blood cell count, and individuals which increased white blood cell count more likely to have metabolic syndrome in Japanese men. We investigated whether similar relationship can be observed also in women. We analyzed the data from 16,383 Japanese women who underwent general health screening. Age-adjusted logistic regression analysis showed that current smoking was positively associated with a highest white blood cell count quartile with an odds ratio of 2.40 (95% CI: 2.16-2.68, P<0.0001). The white blood cell count showed a graded association with metabolic syndrome. On the other hand, the association between current smoking and metabolic syndrome was no longer significant after subdividing the individuals into groups according to the white blood cell quartile. These data collectively suggested that the association between current smoking and metabolic syndrome is heavily confounded by certain factors that increase the circulating white blood cell count in Japanese women, as in men.

Cigarette smoking and irinotecan treatment: pharmacokinetic interaction and effects on neutropenia

PURPOSE

Several constituents of cigarette smoke are known to interact with drug metabolizing enzymes and potentially affect treatment outcome with substrate drugs. The purpose of this study was to determine the effects of cigarette smoking on the pharmacokinetics and adverse effects of irinotecan.

PATIENTS AND METHODS

A total of 190 patients (49 smokers, 141 nonsmokers) treated with irinotecan (90-minute intravenous administration on a 3-week schedule) were evaluated for pharmacokinetics. Complete toxicity data were available in a subset of 134 patients receiving 350 mg/m2 or 600 mg flat-fixed dose irinotecan.

RESULTS

In smokers, the dose-normalized area under the plasma concentration-time curve of irinotecan was significantly lower (median, 28.7 v 33.9 ng x h/mL/mg; P = .001) compared with nonsmokers. In addition, smokers showed an almost 40% lower exposure to SN-38 (median, 0.54 v 0.87 ng x h/mL/mg; P < .001) and a higher relative extent of glucuronidation of SN-38 into SN-38G (median, 6.6 v 4.5; P = .006). Smokers experienced considerably less hematologic toxicity. In particular, the incidence of grade 3 to 4 neutropenia was 6% in smokers versus 38% in nonsmokers (odds ratio [OR], 0.10; 95% CI, 0.02 to 0.43; P < .001). There was no significant difference in incidence of delayed-onset diarrhea (6% v 15%; OR, 0.34; 95% CI, 0.07 to 1.57; P = .149).

CONCLUSION

This study indicates that smoking significantly lowers both the exposure to irinotecan and treatment-induced neutropenia, indicating a potential risk of treatment failure. Although the underlying mechanism is not entirely clear, modulation of CYP3A and uridine diphosphate glucuronosyltransferase isoform 1A1 may be part of the explanation. The data suggest that additional investigation is warranted to determine whether smokers are at increased risk for treatment failure.

Changes in markers of epithelial permeability and inflammation in chronic smokers switching to a nonburning tobacco device (Eclipse)

Eclipse, produced by R. J. Reynolds Tobacco Company, is a potential reduced exposure product (PREP) that heats rather than burns tobacco. We hypothesized that switching to Eclipse would result in relative normalization of pulmonary epithelial permeability, airway inflammation, and blood leukocyte activation in current smokers. We assessed 10 healthy smokers (aged 21-50 years, 19+/-8 pack-years) at baseline and after 2 and 4 weeks of switching to Eclipse, for symptoms, pulmonary function, airway inflammation, lung clearance of (99m)technicium-diethylenetriaminepentaacetic acid, and blood leukocyte activation and production of reactive oxygen species. Values were compared before and after Eclipse use and with those of healthy, lifetime nonsmokers (aged 18-53 years). Compared with baseline values before switching to Eclipse, lung permeability half-time increased from 33+/-3 to 43+/-6 min (p = .017) after 2 weeks and to 44+/-7 min (p = .10) after 4 weeks of Eclipse use. Carboxyhemoglobin levels increased from 5%+/-2% to 7%+/-2% (p<.01) at 4 weeks. Compared with smoking the usual brand of cigarettes, after smoking Eclipse the percentage of natural killer cells, the expression of intercellular adhesion molecule-1 on monocytes, and the expression of CD45RO on T cells showed significant improvement. However, expression of other surface markers, notably CD23 on monocytes, became more abnormal. Production of reactive oxygen species by smokers' neutrophils and monocytes increased further with Eclipse use. We found no significant effects on pulmonary function, cells in induced sputum, or exhaled nitric oxide. Switching to Eclipse reduces alveolar epithelial injury in some smokers but may increase carboxyhemoglobin levels and oxidative stress.

Total and differential leukocytes counts, but not hsCRP, ESR, and five fractioned serum proteins have significant potency to predict stable coronary artery disease

BACKGROUND

The role and diagnostic value of markers of inflammation is well recognized in acute coronary syndromes but it is uncertain in patients with stable coronary artery disease (CAD). This study was done to investigate the association of markers of inflammation with the occurrence and severity of CAD and to evaluate their predictive values.

METHODS

Markers of inflammation, electrophoresis serum protein fractions, serum (apo)lipoproteins and classical risk factors were determined in 270 angiographically documented subjects. The subjects were classified as CAD cases and controls according to angiography. The severity of CAD was scored on the basis of the number and extent of lesions.

RESULTS

The counts of total leukocytes (7.14+/-1.86 cell/nl vs. 6.58+/-1.62, p<or=0.02), neutrophils (3.95+/-1.42 vs. 3.59+/-1.07, p<or=0.05) and eosinophils (0.25+/-0.28 vs. 0.19+/-0.24, p<or=0.03) were increased significantly, whereas the concentrations of high-sensitivity C-reactive protein (hsCRP, 2.03 (0.0-32.0) mg/l vs.1.72 (0.09-11.36), p<or=0.07) changed modestly in CAD patients relative to controls. There were no significant differences in the counts of monocytes and lymphocytes and the concentrations of erythrocyte sedimentation rate (ESR) and any five fractions of serum proteins between two groups. The counts of total leukocytes, neutrophils and eosinophils, but not hsCRP and ESR exhibited significant associations with the severity of CAD. In univariate logistic regression analysis, leukocytes count associated significantly (OR=1.97, p<or=0.01) whereas hsCRP modestly (OR=1.76, p<or=0.06) with the occurrence of CAD. The association was lessened by diabetes mellitus in multivariable adjustment. Receiver operating characteristic (ROC) analysis showed that, only total leukocyte and differential counts had significant potency to predict CAD (area under curve, AUC=0.60+/-0.04, p<or=0.02).

CONCLUSIONS

The total leukocytes count and its subgroups are associated with the presence and severity of CAD, but the associations were not independent. The efficiency was questioned for hsCRP, ESR and five fractioned serum proteins to identify stable CAD.

Association of metabolic syndrome with white blood cell subtype and red blood cells

Inflammation and thrombogenesis have been suggested as possible causes for cardiovascular events in patients suffering from metabolic syndrome (MS). The primary objective of this study was to determine the relationship between red blood cell (RBC) or white blood cell (WBC) subtypes and MS. The secondary objective was to reveal any gender differences inherent to this association. Body mass index (BMI), blood pressure, serum high-density lipoprotein cholesterol, triglycerides, and glucose were measured. The numbers of WBC subtypes and RBCs were determined in healthy adults. In male subjects, the numbers of total leukocytes, neutrophils, and lymphocytes was elevated in the MS patients (P<0.05). In the male subjects, the numbers of total leukocytes, neutrophils, and lymphocytes were elevated in accordance with the metabolic component count (P<0.05). RBC, monocyte, eosinophil, and basophil counts did not differ in accordance with metabolic component counts (r = 0.406, r = 0.304, r = 0.366; P<0.05). In the female subjects, we determined there to be no differences in the numbers of RBC and WBC subtypes in the MS patients, in accordance with metabolic component counts. The numbers of total leukocytes, neutrophils, and lymphocytes were elevated in the male MS subjects in this study, and these counts increased in accordance with the metabolic component counts. In the female subjects in this study, we determined there to be no association between RBC and WBC subtype counts with MS.

Medical check-up findings characteristic of smokers: aimed at improving smoking cessation interventions by physicians

OBJECTIVE

The purpose of this study was to elucidate the medical check-up findings associated with smoking habit, which medical professionals, particularly physicians, should use for the promotion of quitting smoking.

METHODS

In 6,215 male and 1,627 female employees who participated in annual medical check-up, we compared the results of each test between smokers and nonsmokers.

RESULTS

Many results were significantly different between smokers and nonsmokers in both males and females. Among them, the hematocrit, leukocyte count, and levels of hemoglobin and triglyceride were significantly higher, the level of high-density lipoprotein cholesterol was significantly lower, and the frequencies of positive urinary occult blood and hearing loss were significantly higher in male smokers than in male nonsmokers. Furthermore, the hematocrit, leukocyte count, positive urinary occult blood, hearing loss, and levels of hemoglobin, triglyceride, and high-density lipoprotein cholesterol showed significant trends for male nonsmoker, and light, moderate, and heavy male smokers, that is, significant associations with larger numbers of cigarettes smoked per day.

CONCLUSION

Not only polycythemia and low high-density lipoprotein cholesterol level but also high leukocyte count, hearing loss, positive urinary occult blood, and high triglyceride level are smoking-related abnormal findings. In the medical check-up, medical professionals should inform smokers of these data and encourage them to quit smoking.

Effects of Cigarette Reduction on Cardiovascular Risk Factors and Subjective Measures

STUDY OBJECTIVES

To assess the effect of continued smoking and smoking reduction on cardiovascular biomarkers (eg, WBC count, cholesterol concentrations, BP, heart rate).

DESIGN, SETTING, AND PARTICIPANTS

This study, conducted at the University of Minnesota, randomized smokers interested in significantly reducing cigarette use but not quitting to either start 12 weeks of smoking reduction immediately (n = 102), assisted by nicotine replacement therapy, or to a 6-week wait list (n = 49). Those starting smoking reduction were required to reduce smoking by 25% for 2 weeks, 50% for 2 weeks, and 75% during the final 2 weeks. After 6 weeks, the subjects were asked to maintain a 50% reduction or quit. Nicotine gum and, if necessary, nicotine patch were used to achieve reduction goals. The wait list group (n = 49) smoked ad libitum for 6 weeks and then reduced smoking as previously described.

MEASUREMENTS AND RESULTS

Cardiovascular biomarkers (eg, WBC count, cholesterol concentrations, BP, heart rate) were assessed at several time points after enrollment. During ad libitum smoking, cardiovascular biomarkers remained relatively stable with correlation coefficients across the various time measurements, ranging from 0.44 to 1.00 (p < 0.01 for all measures). Among successful nonabstinent reducers (64 of 151 subjects), significant improvements were found in many biomarkers (eg, hemoglobin, hematocrit, RBC and WBC counts, lipids, BP, heart rate, respiratory symptoms, all p < 0.0167).

CONCLUSIONS

These results show the availability of reliable and dose-sensitive biomarkers and that reduction in smoking can lead to significant but only modest changes in cardiovascular risk factors in healthy smokers. It is not known whether the reductions in cardiovascular risk factors observed after smoking reduction are also associated with reduced disease risk. Additional research is necessary to address this issue.