Cigarette Smoking, and Blood Monocyte Count Correlate with Chronic Lung Injuries and Mortality

Area of Science:

• Pulmonary Medicine
• Immunology
• Toxicology

Background:

• Cigarette smoking (CS) is linked to monocytosis, a condition associated with chronic lung injuries.
• The complex mechanisms underlying this association require further investigation.

Purpose of the Study:

• To determine correlations between measures of cigarette smoking and monocyte counts.
• To assess the predictive capacity of these measures for chronic lung diseases.
• To investigate the association between cigarette smoking, monocytosis, and mortality.

Main Methods:

• A retrospective study of 382 patients undergoing surgical resection for suspected lung nodules/masses.
• Quantification of CS using cigarettes per day (CPD), duration, composite pack years (CPY), current smoking status, and cessation years.
• Multivariate logistic regression analysis to identify significant predictors.

Main Results:

• Composite pack years (CPY) and smoking duration correlated positively with monocyte percentage.
• CPY was associated with airway obstruction, hyperinflation, and reduced diffusion capacity (DLCO).
• Smoking metrics correlated with various lung pathologies including emphysema, fibrosis, and lung cancer; monocytosis predicted fibrosis and mortality.

Conclusions:

• Cigarette smoking metrics and elevated monocyte counts are linked to chronic lung disease endpoints, suggesting a role in pathogenesis.
• Smoking duration may be a better marker for monocytosis and associated lung diseases.
• Monocytosis is a predictor of lung fibrosis and mortality in patients with a history of smoking.