PubMed Health⌕ Search

Biomedical subjects

G L Delclos

Publications and source records attributed to G L Delclos.

At least 19 recordsLinked to original sources

Associations between temporary employment and occupational injury: what are the mechanisms?

OBJECTIVE: To determine whether observed higher risks of occupational injury among temporary workers are due to exposure to hazardous working conditions and/or to lack of job experience level. METHODS: Data systematically recorded for 2000 and 2001 by the Spanish Ministry of Labour and Social Affairs on fatal and non-fatal traumatic occupational injuries were examined by type of employment and type of accident, while adjusting for gender, age, occupation, and length of employment in the company. In the study period there were 1500 fatal and 1 806 532 non-fatal traumatic occupational injuries that occurred at the workplace. Incidence rates and rate ratios (RR) were estimated using Poisson regression models. RESULTS: Temporary workers showed a rate ratio of 2.94 for non-fatal occupational injuries (95% CI 2.40 to 3.61) and 2.54 for fatal occupational injuries (95% CI 1.88 to 3.42). When these associations were adjusted by gender, age, occupation, and especially length of employment, they loose statistic significance: 1.05 (95% CI 0.97 to 1.12) for non-fatal and 1.07 (95% CI 0.91 to 1.26) for fatal. CONCLUSIONS: Lower job experience and knowledge of workplace hazards, measured by length of employment, is a possible mechanism to explain the consistent association between temporary workers and occupational injury. The role of working conditions associated with temporary jobs should be assessed more specifically.

Accidents, Occupational↗

Validation of an asthma questionnaire for use in healthcare workers.

BACKGROUND: Previous studies have described increased occurrence of asthma among healthcare workers, but to our knowledge there are no validated survey questionnaires with which to study this occupational group. AIMS: To develop, validate, and refine a new survey instrument on asthma for use in epidemiological studies of healthcare workers. METHODS: An initial draft questionnaire, designed by a multidisciplinary team, used previously validated questions where possible; the occupational exposure section was developed by updating health services specific chemical lists through hospital walk-through surveys and review of material safety data sheets. A cross-sectional validation study was conducted in 118 non-smoking subjects, who also underwent bronchial challenge testing, an interview with an industrial hygienist, and measurement of specific IgE antibodies to common aeroallergens. RESULTS: The final version consisted of 43 main questions in four sections. Time to completion of the questionnaire ranged from 13 to 25 minutes. Test-retest reliability of asthma and allergy items ranged from 75% to 94%, and internal consistency for these items was excellent (Cronbach's alpha > or = 0.86). Against methacholine challenge, an eight item combination of asthma related symptoms had a sensitivity of 71% and specificity of 70%; against a physician diagnosis of asthma, this same combination showed a sensitivity of 79% and specificity of 98%. Agreement between self-reported exposures and industrial hygienist review was similar to previous studies and only moderate, indicating the need to incorporate more reliable methods of exposure assessment. Against the aerollergen panel, the best combinations of sensitivity and specificity were obtained for a history of allergies to dust, dust mite, and animals. CONCLUSIONS: Initial evaluation of this new questionnaire indicates good validity and reliability, and further field testing and cross-validation in a larger healthcare worker population is in progress. The need for development of more reliable occupational exposure assessment methods that go beyond self-report is underscored.

Adult↗

Organisational and occupational risk factors associated with work related injuries among public hospital employees in Costa Rica.

AIMS: To explore the relation between occupational and organisational factors and work related injuries (WRI) among public hospital employees in Costa Rica. METHODS: A cross-sectional survey was conducted among a stratified random sample of 1000 employees from 10 of the 29 public hospitals in Costa Rica. A previously validated, self-administered questionnaire which included occupational and organisational factors and sociodemographic variables was used. From the final eligible sample (n = 859), a total of 842 (response rate 98%) questionnaires were returned; 475 workers were analysed after excluding not-at-risk workers and incomplete questionnaires. WRI were computed for the past six months. RESULTS: Workers exposed to chemicals (RR = 1.36) and physical hazards (RR = 1.26) had higher WRI rate ratios than non-exposed workers. Employees reporting job tasks that interfered with safety practices (RR = 1.46), and a lack of safety training (RR = 1.41) had higher WRI rate ratios than their counterparts. Low levels of safety climate (RR = 1.51) and safety practices (RR = 1.27) were individually associated with an increased risk of WRI. Also, when evaluated jointly, low levels of both safety climate and safety practices showed the highest association with WRI (RR = 1.92). CONCLUSIONS: When evaluated independently, most of the occupational exposures and organisational factors investigated were significantly correlated with an increased injury risk. As expected, some of these associations disappeared when evaluated jointly. Exposure to chemical and physical hazards, lack of safety training, and low levels of safety climate and safety practices remained significant risk factors for WRI. These results will be important to consider in developing future prevention interventions in this setting.

Adult↗

Prevalence and risk factors of asthma and wheezing among US adults: an analysis of the NHANES III data.

The prevalence of asthma has been on the increase in the USA and worldwide. To understand the worsening epidemiological trends of asthma, this study analysed the data from the third National Health and Nutrition Examination Survey (NHANES III) to determine the prevalence and risk factors for asthma and wheezing among US adults. This analysis used data from 18,825 US adults aged > or = 20 yrs who had participated in the NHANES III project. After excluding subjects with physician-diagnosed emphysema, a total of 18,393 subjects were included in the final analysis. The prevalence of current asthma (asthma) was 4.5% and the prevalence of wheezing in the previous 12 months (wheezing) was 16.4%. Mexican-Americans exhibited the lowest prevalence of asthma when compared with other race/ethnic groups. Multiple logistic regression analysis showed that Mexican-Americans were less likely to report asthma when compared to non-Hispanic whites. Low education level, female sex, current and past smoking status, pet ownership, lifetime diagnosis of physician-diagnosed hay fever and obesity were all significantly associated with asthma and/or wheezing. No significant effect of indoor air pollutants, as derived from the use of household heating/cooking appliances, on asthma and wheezing was observed in this study. In conclusion, this study observed racial/ethnic differences in the prevalence of asthma and wheezing and identified several important risk factors that may contribute to development and/or exacerbation of asthma and wheezing. Contrary to earlier reports, the proxy measures of indoor air pollution used in this study were not found to be associated with increased risk of asthma and wheezing.

Adult↗

Prevalence and risk factors of work related asthma by industry among United States workers: data from the third national health and nutrition examination survey (1988-94).

OBJECTIVES: To estimate the prevalence of work related asthma and work related wheezing in United States workers. To identify high risk industries that could be targeted for future intervention. To determine the population attributable risk of work related asthma and work related wheezing. METHODS: The third national health and nutrition examination survey, 1988-1994 (NHANES III) was analyzed to determine the prevalence of work related asthma and wheezing and to identify initially defined industries at risk among United States workers aged 20 and older. Separate logistic models were developed with work related asthma and work related wheezing as outcomes. Work related asthma was defined as affirmative response to questions on self reported physician diagnosed asthma and work related symptoms of rhinitis, conjunctivitis, and asthma. Work related wheezing was defined as affirmative response to questions on self reported wheezing or whistling in the chest in the previous 12 months and work related symptoms of rhinitis, conjunctivitis, and asthma. All analyses were adjusted for age, sex, smoking, and atopy. RESULTS: The prevalence of work related asthma was 3.70% (95% confidence interval (95% CI) 2.88 to 4.52) and the prevalence of work related wheezing was 11.46% (95% CI 9.87 to 13.05). The main industries identified at risk of work related asthma and wheeze included the entertainment industry; agriculture, forestry, and fishing; construction; electrical machinery; repair services; and lodging places. The population attributable risk for work related asthma was 36.5% and work related wheezing was 28.5%. CONCLUSIONS: The findings provide impetus for further research and actions by public health professionals which prioritise occupational asthma on the public health agenda. Future intervention strategies need to be developed for effective control and prevention of asthma in the workplace.

Adult↗

Prevalence and correlates of smoking on the roof of the world.

OBJECTIVE: To determine the prevalence and correlates of cigarette smoking among adults in high mountain rural areas of northern Pakistan. DESIGN: Cross sectional survey. PARTICIPANTS: A sample of 4203 adults (aged 18 years and over) were selected by stratified random sampling from 16 villages. MAIN OUTCOME MEASURE: Self reported smoking prevalence; age of smoking initiation; daily cigarette consumption and association between current smoking and sociodemographic variables, use of snuff, wine, body mass index, blood pressure, family history of stroke, and hypertension. RESULTS: 614/1406 men (43.7%) and 154/2797 (5.5%) women reported smoking cigarettes. The age standardised prevalence of smoking was 40.5% for men and 6.3% for women. Men were more likely (odds ratio (OR) 6.5, 95% confidence interval (CI) 4.75 to 8.79) to be smokers. Smokers were more likely to use snuff (OR 1.39, 95% CI 1.12 to 1.73), drink wine (OR 3.47, 95% CI 2.81 to 4.29), and were more likely to work as farmers (OR 1.55, 95% CI 1.05 to 2.29) or shopkeepers (OR 2.63, 95% CI 1.67 to 4.14). Individuals with college level education and with desirable body mass index were less likely to smoke (OR 0.55, 95% CI 0.35 to 0.87; OR 0.74, 95% CI 0.57 to 0.96). CONCLUSION: Cigarette smoking is a major public health problem in this high mountain community of Pakistan, particularly among the male population, the majority of whom begin to smoke quite early in life. A comprehensive tobacco control effort incorporated into the existing community based health infrastructure is needed.

Adolescent↗

Genetic variants of myeloperoxidase and lung cancer risk.

The cytochrome P450 family of enzymes is responsible for many of the initial metabolic conversions of procarcinogenic compounds in tobacco smoke to reactive metabolites. However, other enzyme-based systems such as myeloperoxidase (MPO) may also be involved in this metabolic process. MPO is a phase I metabolic enzyme that has a polymorphic region upstream of the gene that appears to reduce transcriptional activity. The polymorphic G-->A nucleotide base shift negates the binding region for the general transcription factor SP1. Thus, individuals with the variant allele may be provided with a protective effect due to decreased metabolic conversion of carcinogenic compounds in tobacco smoke. This study has investigated the hypothesis that individuals with the variant allele may be at a reduced risk for lung cancer. Our results demonstrate that the protective effects of the MPO variant allele reduced overall lung cancer risk in Caucasians by 48% (OR = 0.52, 95% CI 0.30-0.90, P = 0.02). There was a 72% protective effect (OR = 0.28, 95% CI 0.12-0.61, P < 0.05) evident in men but not in women. Additionally, in younger individuals (<61 years) there was a statistically significant 72% reduction in risk (OR = 0.28, 95% CI 0. 11-0.69, P < 0.05) but not in older individuals. A protective effect was observed for current smokers (OR = 0.24, 95% CI 0.10-0.58, P < 0. 05) but not in former smokers and those who had never smoked. These data demonstrate that there is a reduction in lung cancer risk associated with a variant allele of MPO that is evident in men, younger individuals and current smokers.

Base Sequence↗

Allelic deletion analyses of MMAC/PTEN and DMBT1 loci in gliomas: relationship to prognostic significance.

The frequency of loss of heterozygosity (LOH) around MMAC/PTEN and DMBT1 loci and survival analyses based on the LOH status were assessed in 110 patients with different histological groups of gliomas. Twenty-six of the patients had anaplastic oligodendrogliomas, 31 had anaplastic astrocytomas, and 53 had glioblastomas multiforme (GM). At the DMBT1 locus, LOH was observed very frequently in all three histological groups, with no significant difference in the frequency of LOH among the three histological groups. At the MMAC/PTEN locus, patients with GM exhibited a significantly increased frequency of LOH (72%) compared with patients with anaplastic astrocytomas (29%) or anaplastic oligodendrogliomas (31%) (P < 0.0001). Kaplan-Meier survival plots showed that patients with LOH at the MMAC/PTEN locus had a significantly worse prognosis than did patients without LOH at the MMAC/PTEN locus [hazard ratio (LOH versus non-LOH), 2.65; 95% confidence interval (CI), 1.69-4.46; P < 0.0001]. Cox proportional hazards regression analysis, adjusted for age at surgery and histological grades (GM and non-GM), showed that LOH at the MMAC/PTEN locus was a significant predictor of shorter survival [hazard ratio (LOH versus non-LOH), 2.01; 95% CI, 1.1-3.5; P = 0.018). Our analysis failed to indicate a similar association between the frequency of LOH at the DMBT1 locus and patient survival [hazard ratio (LOH versus non-LOH), 2; 95% CI, 0.37-3.13; P = 0.2]. These results suggest that the DMBT1 gene may be involved early in the oncogenesis of gliomas, whereas alterations in the MMAC/PTEN gene may be a late event in the oncogenesis related to progression of gliomas and provide a significant prognostic marker for patient survival.

Agglutinins↗

The effectiveness of a needleless intravenous connection system: an assessment by injury rate and user satisfaction.

OBJECTIVE: To assess the impact of a needleless intravenous (i.v.) connection system on the rate of reported intravenous-connection-related (IVCR) percutaneous injuries, and to assess user satisfaction, frequency of use, and barriers to use. DESIGN: A pre-post intervention design, with injury incidence rates being compared 3 years before and 1 year after hospital wide device implementation; and a cross-sectional descriptive user satisfaction survey. SETTING: Two tertiary-care teaching hospitals, one general and one pediatric, located in a large metropolitan medical center. OUTCOME VARIABLE: All IVCR percutaneous injuries reported to the employee health services at both hospitals during the years from 1989 to 1991 and 1993. STUDY POPULATION: Survey participants were selected randomly from licensed nursing employees at both hospitals. INTERVENTION: i.v. connection system consisting of blunt plastic cannulas and compressed latex injection sites. RESULTS: After device implementation, the IVCR injury rate was reduced 62.4% (rate ratio [RR], 0.38; 95% confidence interval [CI95], 0.27-0.53) at the general hospital and 70.2% (RR, 0.30; CI95, 0.17-0.53) at the pediatric hospital. After adjusting for the reduction in injury rate due to factors other than device implementation, the IVCR injury rate was reduced 54.5% (adjusted RR, 0.46; CI95, 0.32-0.65) at the general hospital and 57.2% (adjusted RR, 0.43; CI95, 0.24-0.78) at the pediatric hospital. Approximately 94% of survey respondents (n = 478, response rate = 51%) were satisfied with the device and recommended continued use. However, needles still were being used for activities that could have been performed with the needleless system because of compatibility, accessibility, and other technical problems related to the device. CONCLUSIONS: The device was effective in reducing the rate of reported IVCR percutaneous injuries and users were satisfied with the device, but barriers to universal use were identified.

Cross-Sectional Studies↗

Associations between cytochrome P4502E1 genotype, mutagen sensitivity, cigarette smoking and susceptibility to lung cancer.

Cytochrome P4502E1 (CYP2E1) is involved in the metabolic activation of carcinogenic N-nitrosoamines. We therefore assessed the genotype frequencies of PstI or RsaI CYP2E1 restriction fragment length polymorphisms and another susceptibility marker, mutagen sensitivity, in 137 lung cancer cases (92 African American and 45 Mexican American) and 206 controls (114 African American and 92 Mexican American) identified in a molecular epidemiological study of lung cancer. The CYP2E1 c1/c1 genotype was found in 86.7% of Mexican American cases, 70.6% of Mexican American controls, 89.1% of African American cases and 86.8% of African American controls. By multivariate analysis, this genotype was found to be associated with a 14.0-fold increased risk of lung cancer in Mexican Americans but not in African Americans; a 9.9-fold increased risk of lung cancer in Mexican American former smokers, but not in non-smokers or current smokers; a 15-fold increased risk of lung cancer in Mexican American males, but not in females. Patients with the susceptible genotype appeared to have developed cancer at an earlier age and with lower cigarette pack-year of exposure than did patients with the c1/c2 or c2/c2 genotypes. Stratified analysis suggested a greater than multiplicative interaction between cigarette smoking and CYP2E1 c1/c1 genotype, although not statistically significant. The odds ratios (ORs) for the CYP2E1 c1/c1 genotype, cigarette smoking and both risk factors combined were 1.3, 6.7 and 16.3, respectively. The association between CYP2E1 c1/c1 genotype and pack-years of smoking followed the same pattern. The interaction between mutagen sensitivity and CYP2E1 c1/c1 genotype was especially strong in former smokers (the ORs for the CYP2E1 c1/c1 genotype, mutagen sensitivity and both risk factors combined were 3.9, 5.4 and 23.0, respectively). Therefore, the data suggest that individuals who lack a c2 allele might be at higher risk for developing lung cancer.

Alleles↗

Compliance with universal precautions among physicians.

This study characterized and assessed self-reported levels of compliance with universal precautions (UP) among hospital-based physicians, and determined significant factors associated with both compliance and noncompliance. The physicians (n = 322) were a subgroup of a larger study population of hospital-based health care workers recruited from three geographically distinct locations (n = 1746), and were surveyed using a detailed confidential questionnaire that assessed personal, work-related, and organizational factors. Compliance with UP was measured through 11 items that examined how often physicians followed specific recommended work practices. Compliance was found to vary among the 11 items: they were high for certain activities (eg, glove use, 94%; disposal of sharps, 92%) and low for others (eg, wearing protective clothing, 55%; not recapping needles, 56%). Compliance with all items was low (31% to 38%). Stepwise logistic regression revealed that noncompliant physicians were likely to be age 37 or older, to report high work stress, and to perceive a conflict of interest between providing patient care and protecting themselves. Compliant physicians were more likely to be knowledgeable and to have been trained in universal precautions, to perceive protective measures as being effective, and to perceive an organizational commitment to safety.

Adult↗

Controversy of oral contraceptives and risk of rheumatoid arthritis: meta-analysis of conflicting studies and review of conflicting meta-analyses with special emphasis on analysis of heterogeneity.

The authors analyze the heterogeneity present in the combined results of past observational studies that investigated the association between oral contraceptive use and rheumatoid arthritis. The authors also evaluate discrepancies among meta-analyses that focus on the same relation. Of the 15 initially reviewed studies, 10 were selected for this meta-analysis, which also includes a qualitative summary of study characteristics and a critical appraisal of study quality. The authors used the direct method to combine the study results when there was no evidence of heterogeneity and the DerSimonian-Laird method when heterogeneity was present. Using a meta-regression to assess the sources of heterogeneity, the authors weighted summary estimates by sample size and undertook a sensitivity analysis. There was a strong indication of heterogeneity when combining all studies (x2 = 29.34, p = 0.00060) with the source of controls explaining most of the heterogeneity. The most important factor in explaining the differences among the overall summary estimates given by the meta-analyses is that different effect estimates had been selected for the same studies. There is no conclusive evidence of a protective effect of oral contraceptives on the risk of developing rheumatoid arthritis. Consensus is needed on how meta-analyses of observational studies should be conducted.

Arthritis, Rheumatoid↗

Survival of cells with bleomycin-induced chromosomal lesions in the cultured lymphocytes of lung cancer patients.

In a previous study of lung cancer, we showed that bleomycin, a radiomimetic agent, induced breaks preferentially on chromosomes 4 and 5. The molecular cytogenetic study reported here, using chromosome painting and G banding, was designed to assess whether the chromatid breaks induced by bleomycin could survive as chromosome-type aberrations after treated lymphocyte populations were allowed to recover in a drug-free medium for one or two cell generations and whether the survival rates of lesions on chromosomes 4 and 5 differed in cases with lung cancer and controls. The findings from 16 cases and 14 controls showed that in samples allowed to recover for 48 h, most aberrations were of the chromosome type. The proportion of chromosome 5 abnormalities surviving as chromosome-type aberrations was significantly higher in the cells of lung cancer cases (13.4%) than in controls (4.6%; P < 0.0001). However, no significant differences in survival of chromosome 4 abnormalities were detected between cases and controls. The proportions of chromosome 5q13-q22 abnormalities were 5.3% in the cases and 0.6% in the controls (P < 0.0001). 5q13-q22 regions encompassed 38.4% of all abnormalities on chromosome 5 in the cases but only 14.5% in the controls. Therefore, the survival rate of chromosome 5 lesions (especially those at 5q13-q22) in lymphocytes might be used as a biomarker to identify populations at high risk for lung cancer.

Antibiotics, Antineoplastic↗

Compliance with universal precautions among health care workers at three regional hospitals.

OBJECTIVE: To assess and characterize self-reported levels of compliance with universal precautions among hospital-based health care workers and to determine correlates of compliance. DESIGN: Confidential questionnaire survey of 1716 hospital-based health care workers. PARTICIPANTS: Participants were recruited from three geographically distinct hospitals. A stratified convenience sample of physicians, nurses, technicians, and phlebotomists working in emergency, surgery, critical care, and laboratory departments was selected from employment lists to receive the survey instrument. All participants had direct contact with either patients or patient specimens. RESULTS: For this study, overall compliance was defined as "always" or "often" adhering to the desired protective behavior. Eleven different items composed the overall compliance scale. Compliance rates varied among the 11 items, from extremely high for certain activities (e.g., glove use, 97%; disposal of sharps, 95%) to low for others (e.g., wearing protective outer clothing, 62%; wearing eye protection, 63%). Compliance was strongly correlated with several key factors: (1) perceived organizational commitment to safety, (2) perceived conflict of interest between workers' need to protect themselves and their need to provide medical care to patients; (3) risk-taking personality; (4) perception of risk; (5) knowledge regarding routes of HIV transmission; and (6) training in universal precautions. Compliance rates were associated with some demographic characteristics: female workers had higher overall compliance scores than did male workers (25% of female and 19% of male respondents circled "always" or "often" on each of the 11 items, p < 0.05); and overall compliance scores were highest for nurses, intermediate for technicians, and lowest for physicians. Overall compliance scores were higher for the mid-Atlantic respondents (28%) than for those from the Southwest (20%) or Midwest (20%, p = 0.001). CONCLUSIONS: This study supports earlier findings regarding several compliance correlates (perception of risk, knowledge of universal precautions), but it also identifies important new variables, such as the organizational safety climate and perceived conflict of interest. Several modifiable variables were identified, and intervention programs that address as many of these factors as possible will probably succeed in facilitating employee compliance.

Blood-Borne Pathogens↗

A case-control study of wood dust exposure, mutagen sensitivity, and lung cancer risk.

The associations between lung cancer risk, mutagen sensitivity (a marker of cancer susceptibility), and a putative lung carcinogen, wood dust, were assessed in a hospital-based case-control study. There were 113 African -American and 67 Mexican-American cases with newly diagnosed, previously untreated lung cancer and 270 controls, frequency-matched on age, ethnicity, and sex. Mutagen sensitivity ( 1 chromatid break/cell after short-term bleomycin treatment) was associated with statistically significant elevated risk for lung cancer [odds ration (OR) = 4.3; 95% confidence intervals (CI) = 2.3-7.9]. Wood dust exposure was also a significant predictor of risk (overall OR = 3.5; CI = 1.4-8.6) after controlling for smoking and mutagen sensitivity. When stratified by ethnicity, wood dust exposure was s significant risk factor for African-Americans (OR = 5.5; CI = 1.6-18.9) but not for Mexican-Americans (OR = 2.0; CI = 0.5-8.1). The ORs were 3.8 and 4.8 for non-small cell lung cancer in Mexican-Americans (CI = 1.2-18.5). Stratified analysis suggested evidence of strong interactions between wood dust exposure and both mutagen sensitivity and smoking in lung cancer risk.

Adult↗

Influence of smoking on radiographic profusion and pleural changes in asbestos-exposed subjects.

The influence of smoking on pleural and parenchymal radiographic changes, particularly in asbestos-exposed cohorts, has been debated. We studied this issue in 440 asbestos-exposed subjects referred for evaluation between 1981 and 1985. Information was obtained on age, exposure, and smoking. Chest radiographs were independently read by three "B" readers under blind conditions and it was determined that 80.5% of the subjects had a history of smoking. The odds ratio for smoking and parenchymal opacities greater than or equal to 1/0 was 1.98 (95% confidence interval, 1.2 to 3.3); this association was not affected by adjustment for asbestos exposure and/or age. A dose-response pattern emerged between increasing pack-years and parenchymal opacities greater than or equal to 1/0; the effect between asbestos exposure and smoking appeared to be additive. No associations were found between smoking and pleural abnormalities. The findings in this investigation are consistent with prior studies showing an influence of smoking on radiographic parenchymal, but not pleural, changes, at least in asbestos-exposed groups. The anatomical equivalent of these radiographic changes and their impact, if any, on the natural history of asbestos-associated disease remains unclear.

Aged↗

Bronchoalveolar lavage analysis, gallium-67 lung scanning and soluble interleukin-2 receptor levels in asbestos exposure.

This study examined different markers of lung immunologic and inflammatory responses to previous asbestos exposure. We performed bronchoalveolar lavage (BAL) and gallium-67 (67Ga) lung scans and measured serum and BAL soluble interleukin-2 receptor (IL-2R) and angiotensin-converting enzyme (SACE) levels in 32 subjects with a history of significant asbestos exposure, 14 without (EXP) and 18 with (ASB) radiographic evidence of asbestosis. BAL analysis revealed increases in neutrophils in both ASB and EXP when compared to controls (P less than 0.01), which persisted after adjustment for smoking category. Although significant abnormalities of macrophage and total lymphocyte profiles were not found in the study population, lymphocyte subpopulation analysis revealed elevation of BAL T4/T8 ratios in the entire study group (ASB + EXP) when compared to controls (P less than 0.05), independent of smoking category. 67Ga lung scan activity was increased in 56% of ASB and in 36% of EXP: no correlations between positive scans and different radiological and functional parameters could be found. There was no significant elevation of mean SACE, serum, or BAL IL-2R levels in any of the study categories. These data suggest that asbestos exposure may be associated with parenchymal inflammation, even in the absence of clinical criteria for asbestosis. Abnormalities of gallium uptake and of BAL analysis reflect the clinically inapparent inflammation. The increased BAL T4/T8 ratios observed suggest that abnormal local pulmonary immunoregulation may play a role in the pathogenesis of asbestos-related lung diseases.

Adult↗