Smoke Lungs

JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY 2008, 59, Suppl 6, 19–34
www.jpp.krakow.pl

Review article
J. DOMAGALA-KULAWIK

EFFECTS OF CIGARETTE SMOKE ON THE LUNG
AND SYSTEMIC IMMUNITY
Department of Internal Medicine, Pneumology and Allergology,
Warsaw Medical University, Warsaw, Poland
The influence of tobacco smoke on human health is still an important problem
worldwide. Complexinflammatory processes and changes in the immune system are
crucial in the pathogenesis of smoking related disorders like chronic obstructive lung
disease (COPD), lung cancer, atherosclerosis. The objective of this review is to
present the alterations in the immune system in smokers. The main affected system
by cigarette smoke (CS) is the respiratory tract. In bronchial epithelium metaplastic
anddysplastic changes are accompanied by elevated expression of adhesion
molecules and secretion of many cytokines capable of stimulation immune cells
influx. In the population of pulmonary macrophages an elevated proportion of cells,
changes in expression surface markers with impaired phagocytic and antigen
presenting function are observed. Chronic exposure to CS causes increased
production ofmetalloproteinases (MMP) by macrophages and proteolitic enzymes
by neutrophils. These enzymes cause destruction of alveolar wall. Increased
apoptosis of lung tissue results in augmentation of foreign material which may play
a role of autoantigen and which is a target for cytotoxic/suppressor cells. The role of
regulatory T (Treg) cells in this process is recently postulated. Smoking cessation isthe most effective method of prophylaxis and treatment of diseases related to tobacco
smoking. However many immunological changes in smokers are not completely
reversible after quitting smoking.
K e y w o r d s : immunity, lung, lymphocytes, macrophages, neutrophils, smoking

INTRODUCTION

Tobacco smoking is one of the main health problems of the 19th and 20th
century. It is a causativeagent of such serious diseases as lung cancer and

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chronic obstructive lung disease (COPD) (1). Currently about 1 billion males
and 250 million females across the world smoke. Smoking is said to be
associated with about 50% of deaths due to cardiovascular and pulmonary
diseases (1). In a year 2000 smoking was responsible for 3.84 million deaths in
males and 1 million in females worldwide(2). The most striking pathological
changes related to tobacco smoke are observed in the respiratory tract and,
among them, the influence on immunological status may be considered as
essential. These processes are crucial in the pathogenesis of COPD and cancer
spread. The aim of this article was to review the main immunological changes
caused by tobacco smoke.
Characteristic of cigarettesmokers and distribution of smoke particles in the
respiratory tract

Thousands of substances which are the compounds of tobacco smoke are
inhaled directly or as the products of high temperature combustion on the end of
the cigarette. The final effect of the influence of smoke depends among others, on
environmental conditions. Local homeostasis, genetic predisposition, local
character ofcytokine network, and pathological conditions should be taken into
account during analysis of cigarette smoke (CS) influence on the structural
elements of respiratory tract.
In vivo studies in healthy, asymptomatic smokers are not numerous and the
investigated groups consist only of 10-20 persons. The results of the studies on
immune changes in COPD patients should be interpreted with caution andcan
not be identified with those in smokers without airflow limitation: not all
elements of the inflammation in COPD are related only to smoking (3).
Additional data concerning influence of tobacco smoke on the changes in the
respiratory tract were achieved from the studies performed in lung cancer
patients. The impairment of host defense and an enhanced immunosuppression
are the common...