The expression of adhesion molecules in cigarette smoke-induced airways obstruction

Cigarette smoking produces peripheral airway inflammation in all smokers, and chronic airways obstruction in approximately 20% of heavy smokers. The present study was designed to test the hypothesis that airways obstruction is related to changes in the expression of adhesion molecules involved in the recruitment of cells to sites of inflammation in the lung. Freshly resected lungs from heavy smokers with airways obstruction (n = 10) and from heavy smokers with normal lung function (n = 10) were collected in the operating room, inflated with optimal cutting temperature (OCT) medium and frozen over liquid nitrogen. Six micrometres thick cryostat sections cut from random samples of this tissue were stained, using immunohistochemistry, with monoclonal antibodies to the adhesion molecules on leucocytes: L-selectin, very late activation antigen-4 (VLA-4), CD11a/CD18, CD11b/CD18, CD11c/CD18; and on endothelial and epithelial surfaces: E-selectin, P-selectin, vascular cell adhesion molecule (VCAM-1), intercellular adhesion molecule (ICAM)-1 and ICAM-2 using the alkaline phosphatase anti-alkaline phosphatase (APAAP) technique. The slides were coded and the expression of each molecule scored by three observers using a semiquantitative grading system. Two inducible adhesion molecules, E-selectin on endothelium and CD11b on leucocytes, were also evaluated using quantitative morphometric analysis. The results showed a distribution of adhesion molecules that was consistent with the inflammatory response in the airways and parenchyma of all subjects but failed to show any differences between those with or without airways obstruction. We conclude that development of airways obstruction in heavy smokers cannot be explained by differences in the expression of adhesion molecules known to be involved in the control of cell traffic in the lung.

Association between the p21 codon 31 A1 (arg) allele and lung cancer

In previous investigations p53 polymorphisms and haplotypes have been found to be associated with different types of cancer. In this paper the codon 31 polymorphism of the p53-inducible protein p21 was studied in 144 Swedish lung cancer patients and two different control groups: 95 patients with chronic obstructive pulmonary disease (COPD) and 761 healthy controls. An increased frequency of the p21 codon 31 A1 (arg) allele was found in lung cancer patients, especially in comparison with COPD patients (p = 0.004). There was a significantly increased frequency among lung cancer patients of individuals carrying the arg allele both in comparison with COPD controls (OR = 5.2, 95% CI 1.5-18.1) and healthy controls (OR = 1.7, 95% CI = 1.0-2.9). The results of this and previous studies indicate that allelic variants of both p53 and its effector protein p21 may have an influence on lung cancer.

Risk factors for the development of chronic obstructive pulmonary disease

Cigarette smoking clearly has been shown to be the major environmental risk factor predisposing to the development of COPD. Occupational exposures to dust and fumes, air pollution, passive smoke exposure, childhood respiratory infections, and diet may also contribute. Airway hyperresponsiveness is a risk factor for the development of decline in FEV1, but its role in the development of COPD remains uncertain. Alpha1-antitrypsin deficiency is an important genetic risk factor for COPD in the small minority of COPD patients who inherit this deficiency. Other genetic factors are likely involved but have not yet been identified. Elucidation of additional genetic risk factors may provide useful insights into the pathogenesis of COPD. Potential interactions between the various environmental and genetic risk factors may be extremely important in determining the variable development of COPD.

The worldwide epidemiology of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is common and increasing in prevalence in North America and other industrialized areas. The worldwide epidemiology is multifactorial and complex. Smoking is by far the most important and correctable risk factor. Heredity and environmental risks also relate to the pathogenesis of COPD. Early stages of COPD can only be identified by spirometry. Smoking cessation can retard the progress of the disease and improve prognosis. Reduction or elimination of environmental risks may also be helpful.

Segregation analysis of two lung function indices in a random sample of young families: the Humboldt Family Study

The Humboldt Family Study was conducted in the town of Humboldt, Saskatchewan, in 1993. Familial correlations and segregation analyses of lung function were carried out in 799 individuals in 214 nuclear families that included 214 fathers, 214 mothers, and 371 children. Forced expiratory volume in 1 second (FEV1) and maximal mid-expiratory flow rate (MMFR) were first regressed on age, height, weight, and their quadratic and cubic terms as well as on smoking status in four groups separately (mothers, fathers, daughters, and sons), with terms significant at the 0.10 level being retained. Residual phenotypes were standardized within the four groups. Class D regressive models were used to perform familial correlations and segregation analyses. For both FEV1 and MMFR, father-mother correlations were not significantly different from zero, and mother-offspring, father-offspring, and sibling-sibling correlations showed no statistically significant difference from each other. Based on the "polygenic" models, the estimated intraclass correlation is 0.132 (+/- 0.035) for FEV1 and 0.171 (+/- 0.039) for MMFR, and the narrow-sense heritability is 0.264 for FEV1 and 0.342 for MMFR. Segregation analysis shows that the "mixed" model with both single locus and polygenic components had a better fit for FEV1 than single-locus or polygenic only models. However, the model which included a nontransmitted environmental factor [tau(AA) = tau(AB) = tau(BB) = qA] and polygenic loci had a better fit than the Mendelian model [tau(AA) = 1, tau(AB) = 1/2, tau(BB) = 0] [Akaike's information criterion (AIC) = 2219.47 vs. AIC = 2222.14]. For MMFR, the Mendelian "mixed" model gave a nonsignificant improvement in loge likelihood compared to the simple polygenic model. Comparison of the single-locus model and Mendelian "mixed" model shows no difference in fitting the data. This study suggests that FEV1 and MMFR are controlled by many loci with no major effects and/or common environmental factors.

Alpha 1-antitrypsin-deficient variant Siiyama (Ser53[TCC] to Phe53[TTC]) is prevalent in Japan. Status of alpha 1-antitrypsin deficiency in Japan

In contrast to the fact that alpha 1-antitrypsin (alpha 1-AT) deficiency is one of the most common hereditary disorders of Caucasians, deficient variants among Orientals have been recognized to be extremely rare. Only 12 cases of alpha 1-AT deficiency have been reported in Japan, including five cases in which the genetic defects have already been elucidated: Mnichinan (delta Phe52[TTC] and Gly148[GGG]-->Arg148[AGG]), two unrelated cases of Siiyama (Ser53[TCC]-->Phe53[TTC]), a heterozygote of Mmalton (delta Phe52[TTC]), and one additional case of 14q- syndrome (sporadic deletion of the neighboring region of the alpha 1-AT gene locus). alpha 1-AT Siiyama is a deficient variant originally identified in a 38-yr-old patient with pulmonary emphysema in Japan. The amino acid substitution in this variant occurs in a highly conserved residue of the serpin (serine protease inhibitor) backbone (Seyama K, et al. 1991. J. Biol. Chem. 266:12627-12632). We attempted to determine whether alpha 1-AT deficiency in Japan was caused by independent genetic defects or whether it shared some common mutations in the alpha 1-AT gene. We examined five of seven available families for which the genetic defects causing alpha 1-AT deficiency have not yet been explored. When the allele-specific polymerase chain reaction (PCR) was performed with a pair of oligonucleotide primers having the mutated base sequence of the alpha 1-AT Siiyama allele at the 3' end, all eight cases of alpha 1-AT deficiency among five unrelated families turned out to be homozygous carriers of the alpha 1-AT Siiyama mutation.(ABSTRACT TRUNCATED AT 250 WORDS)

Substance P (NK1)- and neurokinin A (NK2)-receptor gene expression in inflammatory airway diseases

The tachykinin neuropeptides substance P and neurokinin (NK) A have been postulated to participate in the inflammatory reaction in airways of smokers and asthmatics. We have examined the hypothesis that the expression of one or more of the three cloned tachykinin receptors (NK1, NK2, and NK3) is increased in inflammatory airway disorders, which could result in augmentation of the effect of released tachykinin neuropeptides. NK1 receptor and NK2 receptor but not NK3-receptor mRNA were detected by ribonuclease protection assay in RNA from both cartilaginous and membranous bronchi and subpleural lung. In lung samples containing membranous airways, NK2-receptor mRNA expression was increased fourfold in asthmatics compared with nonsmoking controls, whereas NK1-receptor mRNA levels were similar in the two groups. NK1- and NK2-receptor mRNA expression was increased twofold in smokers without airflow obstruction compared with nonsmokers, whereas NK1-receptor mRNA expression was significantly lower in patients with chronic obstructive pulmonary disease compared with smoking controls. In situ hybridization indicated NK1-receptor mRNA was expressed in submucosal glands and airway epithelial cells, whereas NK2-receptor and NK3-receptor mRNA were not detected. These observations have implications for the pathophysiology and treatment of both asthma and tobacco smoke-induced airway inflammation.

P53 polymorphisms and haplotypes in lung cancer

An association between the BstU I 1-1 (Pro-Pro) genotype of the p53 codon 72 polymorphism and lung cancer has previously been reported by Kawajiri et al. A reanalysis of the data by Kawajiri et al. revealed no significant difference between patients and controls with respect to allele frequencies, and the increased frequency of BstU I 1-1 homozygotes was mostly ascribable to a deviation from the Hardy-Weinberg equilibrium. In an attempt to replicate the results by Kawajiri et al. we have studied three p53 polymorphisms (BstU I and Msp I RFLPs in exon 4 and intron 6 respectively and a 16 bp duplication in intron 3) and their haplotypes in Swedish lung cancer patients and controls. The results concerning the codon 72 polymorphism were largely negative. Thus there was no significant association between lung cancer and the BstU I 1-1 type, and only a marginal difference (P = 0.044) with respect to the BstU I allele frequency when lung cancer patients were compared with patients with chronic obstructive pulmonary disease (COPD). However, when the analysis was based on haplotype frequencies larger differences appeared and it was found that only BstU I 1 (pro) alleles linked to 16 bp 1 alleles were associated with lung cancer. Pro alleles linked to the 16 bp duplication appeared instead to confer some protection against cancer. Thus the codon 72 alleles need not be functionally involved in lung cancer, but may rather be markers in linkage disequilibrium with other cancer susceptibility sites on p53.

Effect of cigarette smoking on pulmonary function in each phenotype M of alpha-1-protease inhibitor

Human alpha-1-protease inhibitor (alpha-1-Pi) has been known to be a highly polymorphic protein. We hypothesized that antiprotease activity of each phenotype M of alpha 1-protease inhibitor (PiM) might be different among smokers and that a variation of decrease in pulmonary function for a given amount of cigarette smoking might be associated with PiM phenotypes. To test this, we investigated the effect of cigarette smoking on pulmonary function in each PiM phenotype. The serum level of alpha 1-Pi was measured by the turbidimetric immunoassay and the distribution of PiM phenotypes was determined using isoelectric focusing technique in 247 healthy subjects and 20 COPD patients. Serum levels of alpha-1-antitrypsin of healthy and COPD subjects were 205.1 +/- 31.1 and 179.2 +/- 44.4 (+/- SD) mg/dL, respectively (p > 0.01). The frequency of each PiM phenotype in healthy subjects was shown as follows: M1, 0.555; M1M2, 0.328; M2, 0.041; M1M3, 0.057; M2M3, 0.016; M3, 0.004. The difference in the distribution of PiM phenotypes between healthy and COPD subjects was not significant. Single- and multiple-regression analyses showed that the ratio of FEV1 to forced vital capacity (FVC), in which FEV1 is expressed as percentage of FVC, the maximum flow rate at 50% of FVC divided by measured body height (V50/Ht), and the maximum flow rate at 25% of FVC divided by body height (V25/Ht) were closely related to age and that V25/Ht also was related to smoking index. However, PiM phenotype was unrelated to those pulmonary function variables. We conclude that PiM phenotype is not a major determinant of difference in magnitude of pulmonary impairments caused by cigarette smoking in each individual.

The search for susceptibility genes of COPD

Environmental factors, such as cigarette smoking, outdoor and indoor pollution, and childhood respiratory infections, are believed to play a major role as risk factors for developing chronic obstructive pulmonary disease (COPD). The only confirmed genetic risk factor for COPD is the inherited deficiency of alpha 1-proteinase inhibitor. However, the evidence of familial clustering of lung function and COPD occurrence and the development of COPD among susceptible smokers, at variance with the so-called resistant smokers, would suggest that the weight of genetic risk factors is greater than recognized. In this paper the role of candidate genes for increasing the risk of COPD (such as alpha 1-proteinase inhibitor, alpha 1-antichymotrypsin, cystic fibrosis transmembrane conductance regulator, and others) is reviewed.

Risk factors for chronic obstructive pulmonary disease in a north Italian rural area

To assess the role of risk factors for chronic obstructive lung disease (COPD) by multiple logistic models, the data of the first cross-sectional epidemiological survey in the unpolluted rural area of the Po River Delta were analyzed (n = 2382; 20-64 years). Each subject filled out a standardized questionnaire; 94% of the subjects were also able to perform forced expirograms. Dependent variables were chronic respiratory symptoms, asthma, abnormal parameters of flow-volume curve (ABNFVC), and a complex characterized by chronic phlegm, and/or any wheeze and/or dyspnea grade 2+ and/or diagnosis of asthma and/or an FEV1/FVC ratio less than 60% (ANYABN). Independent variables were: age, ever cigarette smoking (SMK) and lifetime cigarette consumption expressed as pack-years, childhood respiratory infections (CRI), adolescence-adulthood respiratory infections (ARI), familial history for COPD (FCOPD) or for asthma/allergies (FASTHMA), work exposure to dusts/chemicals (EXPO), low socio-economic conditions (SES). A significant relationship with almost all dependent variables was shown by pack-years, ARI and age in both sexes. In males, FCOPD was related to chronic mucus hypersecretion and to ABNFVC, FASTHMA was associated with wheeze and ANYABN. EXPO was related to dyspnea and asthmatic symptoms in both sexes and also to bronchitic symptoms in males. CRI was a significant contributor for asthma symptoms in males, for ANYABN in females. SES had no significant association. In conclusion, our findings show that, beside lifetime cigarette smoking, other host--or environment--related conditions are important risk factors for COPD, suggesting the need for a more thorough strategy for prevention.

Regulation of the alpha 1-antitrypsin gene and a disease-associated mutation in a related enhancer sequence

Ten years ago a search was initiated for DNA variation in the alpha-1-antitrypsin gene (alpha 1-AT) to determine whether there were mutations more commonly associated with patients who had chronic obstructive airways disease (COAD) than with healthy individuals. Using the conventional approach of Southern blotting and searching for restriction fragment length polymorphisms, we identified a potentially useful polymorphism that resulted in the loss of a recognition site for the restriction enzyme, Taq I. The polymorphism occurred in about 17% of patients with COAD and about 5% of the general population (p = 0.0016). The normal sequence in the 3' flanking region of the alpha 1-antitrypsin gene had to be characterized, as it was not known. On the basis of homology, a number of closely clustered sequence motifs demonstrating the characteristics of an enhancer were identified that would potentially increase the transcription and expression of alpha 1-antitrypsin. The normal Taq I sequence occurred in a motif that demonstrated homology to a DNA sequence for octamer transcription factors. The mutation was characterized by in vitro amplification of the region and direct sequencing as a G to A transition (Taq I site TCGA < TCAA). Specific binding of nuclear proteins by gel-shift analysis and DNase I footprinting and increased in vivo transcriptional activity were demonstrated by transfection of mammalian cells containing DNA fragments corresponding to the region of interest. In contrast, the mutant sequence demonstrated loss of binding to nuclear proteins and reduced transcriptional activity. The latter finding was not confined to tissues known to express alpha 1-antitrypsin.(ABSTRACT TRUNCATED AT 250 WORDS)

Genotypes of ALDH2 related to liver and pulmonary diseases and other genetic factors related to alcoholic liver disease

Genetic factors related to the development of alcoholic liver and pancreatic diseases (ALD and APD) and of alcohol-induced asthma were analyzed. The development of ALD is genetically controlled and is directly associated with the polymorphisms of the genes of acetaldehyde (Ac-CHO) and ethanol-metabolizing enzymes, aldehyde dehydrogenase-2 (ALDH2) and cytochrome P4502E1. The development of ALD and APD may also be genetically linked with the induction of gamma-glutamyl transferase (GTT) by alcohol. Alcohol-induced asthma is related to the genotypes of ALDH2 and is caused by rapid elevation of blood Ac-CHO. ALDH1 plays a very important role in the oxidation of Ac-CHO in blood.

Genetic susceptibility to lung cancer with special emphasis on CYP1A1 and GSTM1: a study on host factors in relation to age at onset, gender and histological cancer types

Genetically based differences in metabolism, related to MspI restriction site and Ile-Val polymorphisms of the cytochrome P450 (CYP) 1A1 gene and the null genotype of glutathione transferase class mu (GSTM1), have been reported to be associated with lung cancer susceptibility. The present study was set up to establish the frequencies of the polymorphic genotypes of CYP1A1 and GSTM1 in Sweden, to evaluate a possible increased incidence of the genotypes associated with higher lung cancer risks among Swedish lung cancer patients and to try to make a combined risk estimate for carriers of multiple risk alleles. In a healthy control group, all under 66 years of age, 53% (174/329) of the subjects were of the GSTM1(-) genotype, while in a hospital control group 49% (39/79) carried the GSTM1(-) genotype. In the investigated lung cancer patients this genotype was found in 56% (165/296) and among those patients diagnosed before 66 years of age the deficient genotype was found in 60% (78/131). The highest proportion of the GSTM1(-) genotype was found in patients diagnosed with adenocarcinoma (63%, 29/46) and small cell carcinoma (72%, 21/29) before 66 years of age and among female squamous cell carcinoma patients (79%, 15/19). The allelic variants in CYP1A1 were equally distributed in lung cancer patients and controls. The m1/m2 and m2/m2 genotypes of the MspI site and the Ile/Val genotype were, however, slightly over-represented in squamous cell carcinoma patients. Among patients with squamous cell carcinoma diagnosed before 66 years of age the m1/m2 genotype was found in 28% (10/36), whereas the same genotype was observed in 16% (52/329) of healthy control subjects. A combined risk of squamous cell carcinoma was indicated for patients, diagnosed before 66 years of age, carrying both GSTM1(-) and m2 alleles (OR = 3.0, 95% CI = 1.2-7.2).

Determination of the allelic frequencies of an L-myc and a p53 polymorphism in human lung cancer

The L-myc and p53 genes have been implicated in lung cancer. Both of these genes have restriction fragment length polymorphisms (RFLPs) that could account for differential expression or activity of variant forms. An EcoRI restriction site in the L-myc gene was previously reported to be a predictor of poor prognosis in Japanese lung cancer patients. There are several RFLPs in the p53 gene. In exon 4 there is a polymorphism that codes for either an arginine or proline residue at codon 72. We previously reported the frequency of DNA-RFLPs at these gene loci revealed by EcoRI and AccII respectively. Here we report results from a study comparing lung cancer cases (n = 31) with chronic obstructive pulmonary disease controls (n = 49). No association was found between these RFLPs and disease status. Previous observations that the frequencies of these RFLPs varied by race were confirmed. The p53 arginine allele was found to be more common in Caucasians (0.71) than African-Americans (0.50). The EcoRI restriction site present allele in L-myc was more frequent in African-Americans (0.71) than Caucasians (0.49). Thus, the allelic frequency for L-myc was similar in African-Americans to that reported for Japanese, and the allelic frequency for p53 was similar in Caucasians to that reported for Japanese.

Transforming growth factor beta 1 gene expression in human airways

BACKGROUND

Asthmatic airways have a characteristic deposition of connective tissue under the epithelial basement membrane, but the mediators involved in this alteration are unknown. Several authors have postulated that transforming growth factor beta 1 (TGF-beta 1) could be overexpressed in asthmatic airways.

METHODS

Lung samples from 16 asthmatic patients, six patients with chronic obstructive pulmonary disease (COPD), and six non-obstructed smokers were analysed. RNA was extracted from these tissues to measure expression of TGF-beta 1 by Northern blot analysis using a cDNA probe for TGF-beta 1. The level of expression was quantitated by densitometry using glyceraldehyde 3-phosphate dehydrogenase mRNA as a control. TGF-beta 1 was localised to specific cell types in these lungs by immunohistochemical analysis using polyclonal antibodies specific for intracellular and extracellular TGF-beta 1.

RESULTS

The 2.5 kb TGF-beta 1 mRNA was seen in all 18 samples analysed by Northern blotting and densitometric analysis showed no difference between the asthmatic group (mean (SD) 108% (43%)), the group with COPD (122% (33%)), and the non-obstructed group (100% (49%)). The TGF-beta 1 precursor was immunolocalised throughout the airway wall including the epithelium and in alveolar macrophages. The mature TGF-beta 1 was localised primarily within the connective tissue of the airway wall. These patterns of expression of both forms of TGF-beta 1 were similar in lungs from asthmatic patients, those with COPD, and controls.

CONCLUSIONS

While TGF-beta 1 mRNA and protein are abundantly expressed in human lungs, there is no clear difference in expression between the airways of asthmatic subjects and those of smokers with and without COPD.

Expression of the cystic fibrosis gene in adult human lung

Critical to an understanding of the pulmonary disease in cystic fibrosis (CF) and the development of effective gene therapies is a definition of the distribution and regulation of CF gene expression in adult human lung. Previous studies have detected the product of the CF gene, the CF transmembrane conductance regulator (CFTR), in submucosal glands of human bronchi. In this report, we have characterized the distribution of CFTR RNA and protein in the distal airway and alveoli of human lungs. Samples from eight human lungs were analyzed for CFTR expression by in situ hybridization and immunocytochemistry. CFTR was detected in a subpopulation of epithelial cells at every level of the distal lung, including proximal, terminal, and respiratory bronchioles, and the alveoli. However, there was substantial variation in the level of CFTR expression between samples. In bronchioles, CFTR protein localized to the apical plasma membrane and was found primarily in a subpopulation of nonciliated cells. CFTR was expressed in the same distribution as the Clara cell marker CC10 in proximal bronchioles, however, expression was discordant in the more distal bronchioles and alveoli where CC10 was not detected. These studies suggest that epithelial cells of the distal lung may play a primary role in the pathogenesis of CF as well as expand the spectrum of target cells that should be considered in the development of gene therapies.

[Yellow nail syndrome]

The yellow nail syndrome, first described in 1964 by Samman and White, consists of yellowish, dystrophic nails, lymphedema and pleural effusion. We present the clinical findings of a 53 years old woman who suffered of this very rare syndrome. The literature review reveals the different clinical features which were reported to be associated with the yellow nail syndrome. The pathogenesis of this autosomal-dominantly inherited syndrome consists of a dysfunction of the lymphatic drainage system, but details remain unknown. Up to now a causative treatment does not exist but topic tocopherol may improve the aspect of involved nails. A new study reports of good effects of oral zinc-application to nails and lymphedema.

A leucine-to-proline substitution causes a defective alpha 1-antichymotrypsin allele associated with familial obstructive lung disease

Using denaturing gradient gel electrophoresis and direct sequencing of amplified genomic DNA, we have identified two defective mutants of the human alpha 1-antichymotrypsin (ACT) gene associated with chronic obstructive pulmonary disease (COPD). A leucine 55-to-proline substitution causing a defective ACT allele (Bochum-1) was observed in a family with COPD in three subsequent generations. Another mutation, proline 229-to-alanine (Bonn-1), was associated with ACT serum deficiency in four patients with a positive family history. These mutations were not detected among 100 healthy control subjects, suggesting a possible pathogenetic role of ACT gene defects in a subset of patients with COPD.

Lung cancer, race, and a CYP1A1 genetic polymorphism

The assessment of human cancer risk using molecular epidemiological techniques involves determining the relative contributions of inherited and acquired genetic predispositions, in the context of environmental exposures. Recently described genetic polymorphisms for CYP1A1, a gene involved in the metabolic activation of polycyclic aromatic hydrocarbons, have been associated with lung cancer risk in a Japanese population. We report herein findings from a United States case-control study of lung cancer (56 cases; 48 controls). The polymerase chain reaction followed by an Msp1 restriction enzyme digestion was used to analyze constitutive DNA but no association between the restriction fragment length polymorphism and lung cancer risk was found (odds ratio, 0.7; 95% confidence interval, = 0.3-1.6). Analysis of genotype by cumulative smoking status did not reveal an elevated risk among lesser or greater smokers. The presence of the CYP1A1 Msp1 site-present allele, which was previously found to be associated with Japanese lung cancer risk, was statistically increased in African compared to Caucasian Americans (odds ratio, 2.9; 95% confidence interval, 1.2-2.7). When stratified by race, however, no association between case status and the polymorphism was observed, but the small number of study subjects within each racial group limited the statistical power. Larger studies are required to evaluate the risk of the CYP1A1 Msp1 polymorphism in African Americans.

Biological markers of host susceptibility to air pollutants in epidemiologic studies on chronic airways obstruction

Measuring the variations in risk among individuals or populations of environmentally induced chronic airways obstruction is necessary to develop rational policy to reduce the incidence of those diseases in a given population. Before being able to formulate this policy, however, one must know how to detect those individuals who are susceptible to ari pollutants since they are at increased risk of disease. In the paper the authors discussed several monitoring techniques to detect markers of early biological events relevant to host susceptibility and disease progression. The biological markers are based on genetic traits, pulmonary function tests, biochemical and immune changes. The authors discuss merits and demerits of particular approaches in identifying persons prone to chronic airways obstruction. They stress the point that more research is needed on biochemical and immunological markers of lung injury to assess their usefulness in identifying individuals at higher risk.