Endothelial dysfunction and cardiovascular risk in post-COVID-19 patients after 6- and 12-months SARS-CoV-2 infection.

INTRODUCTION: SARS-CoV-2 infection causes severe endothelial damage, an essential step for cardiovascular complications. Endothelial-colony forming cells (ECFCs) act as a biomarker of vascular damage but their role in SARS-CoV-2 remain unclear. The aim of this study was to assess whether the number of ECFCs and angiogenic biomarkers remained altered after 6 and 12-months post-infection and whether this imbalance correlated with the presence of long-COVID syndrome and other biological parameters measured. METHODS: Seventy-two patients were recruited at different time-points after overcoming COVID-19 and thirty-one healthy controls. All subjects were matched for age, gender, BMI, and comorbidities. ECFCs were obtained from peripheral blood and cultured with specific conditions. RESULTS: The results confirm the presence of a long-term sequela in post-COVID-19 patients, with an abnormal increase in ECFC production compared to controls (82.8% vs. 48.4%, P < 0.01) that is maintained up to 6-months (87.0% vs. 48.4%, P < 0.01) and 12-months post-infection (85.0% vs. 48.4%, P < 0.01). Interestingly, post-COVID-19 patients showed a significant downregulation of angiogenesis-related proteins compared to controls indicating a clear endothelial injury. Troponin, NT-proBNP and ferritin levels, markers of cardiovascular risk and inflammation, remained elevated up to 12-months post-infection. Patients with lower numbers of ECFC exhibited higher levels of inflammatory markers, such as ferritin, suggesting that ECFCs may play a protective role. Additionally, long-COVID syndrome was associated with higher ferritin levels and with female gender. CONCLUSIONS: These findings highlight the presence of vascular sequela that last up to 6- and 12-months post-infection and point out the need for preventive measures and patient follow-up.

Long-term respiratory consequences of COVID-19 related pneumonia: a cohort study.

BACKGROUND: Our aims were to describe respiratory sequelae up to 12 months after discharge in COVID-19 patients with severe pneumonia requiring non-invasive respiratory support therapies. METHODS: This study was undertaken at University Hospital Doctor Josep Trueta (Girona, Spain) between March 2020 and June 2020. Three months after discharge, we evaluated their dyspnoea and performed Saint George's respiratory questionnaire, pulmonary function tests, blood test, 6-min walking test, and a high-resolution CT (HRCT). At the six and 12-month follow-up, we repeated all tests except for pulmonary function, 6-min walking test, and HRCT, which were performed only if abnormal findings had been previously detected. RESULTS: Out of the 94 patients recruited, 73% were male, the median age was 62.9 years old, and most were non-smokers (58%). When comparing data three and 12 months after discharge, the percentage of patients presenting dyspnoea ≥ 2 decreased (19% vs 7%), the quality-of-life total score improved (22.8% vs 18.9%; p = 0.019), there were less abnormal results in the pulmonary function tests (47% vs 23%), the 6-min walking test distance was enhanced (368.3 m vs 390.7 m, p = 0.020), ground glass opacities findings waned (51.6% vs 11.5%), and traction bronchiectasis increased (5.6% vs 15.9%). Only age showed significant differences between patients with and without pulmonary fibrotic-like changes. CONCLUSION: Most patients improved their clinical condition, pulmonary function, exercise capacity and quality of life one year after discharge. Nonetheless, pulmonary fibrotic-like changes were observed during the follow-ups.

Thrombosis Models: An Overview of Common In Vivo and In Vitro Models of Thrombosis.

Occlusions in the blood vessels caused by blood clots, referred to as thrombosis, and the subsequent outcomes are leading causes of morbidity and mortality worldwide. In vitro and in vivo models of thrombosis have advanced our understanding of the complex pathways involved in its development and allowed the evaluation of different therapeutic approaches for its management. This review summarizes different commonly used approaches to induce thrombosis in vivo and in vitro, without detailing the protocols for each technique or the mechanism of thrombus development. For ease of flow, a schematic illustration of the models mentioned in the review is shown below. Considering the number of available approaches, we emphasize the importance of standardizing thrombosis models in research per study aim and application, as different pathophysiological mechanisms are involved in each model, and they exert varying responses to the same carried tests. For the time being, the selection of the appropriate model depends on several factors, including the available settings and research facilities, the aim of the research and its application, and the researchers' experience and ability to perform surgical interventions if needed.

Malignant asbestos-related disease in a population exposed to asbestos.

OBJECTIVES: The first asbestos fiber cement plant in Spain operated in Cerdanyola, in the Barcelona metropolitan area, between 1907 and 1997. We describe clinical and epidemiological characteristics of patients diagnosed with the malignant asbestos-related disease (ARD) in the area of the plant between 2007 and 2016. METHODS: A prospective, descriptive study was undertaken in the 12 municipalities of the county of Barcelona most proximate to the plant. We describe malignant ARD cases by time of diagnosis, source of exposure, periods of exposure and latency, and distribution by sex. Cumulative incidence and age-standardized incidence rates (ASIR) are calculated. RESULTS: Of 477 patients diagnosed with ARD between 2007 and 2016, 128 (26%) presented with asbestos-associated malignancy. Pleural mesothelioma was noted in 105 patients (82.0%) with a linear trend Z-score of -0.2 (NS) in men and 2.7 (P < .01) in women. The highest ASIRs for malignant ARD (6.1/100 000 residents/year; 95% confidence interval [CI], 2.2-13.3) and pleural mesothelioma (4.8/100 000 residents/year; 95% CI, 1.5-11.6) occurred in municipalities closest to the focal point of contamination. The origin of malignant ARD was nonoccupational in 32.2% of men and 81.6% of women (P < .001). CONCLUSIONS: More than 20 years after the closure of the fiber cement plant, the grave consequences of exposure to asbestos remain. The detection of cases of pleural mesothelioma in men seems to have plateaued whereas in women an ascending trend continues, which principally has its origin in nonoccupational exposures.

Cleaning products and short-term respiratory effects among female cleaners with asthma.

OBJECTIVE: We evaluated the short-term effects of exposure to cleaning products on lung function and respiratory symptoms among professional cleaning women. METHODS: Twenty-one women with current asthma and employed as professional cleaners participated in a 15-day panel study. During 312 person-days of data collection, participants self-reported their use of cleaning products and respiratory symptoms in daily diaries and recorded their forced expiratory volume in 1 s (FEV1) and peak expiratory flow (PEF) three times per day using a handheld spirometer. We evaluated associations of cleaning product use with upper and lower respiratory tract symptoms using Poisson mixed regression models and with changes in FEV1 and PEF using linear mixed regression analyses. RESULTS: Participants reported using an average of 2.4 cleaning products per day, with exposure to at least one strong irritant (eg, ammonia, bleach, hydrochloric acid) on 56% of person-days. Among participants without atopy, lower respiratory tract symptoms were associated with the use of hydrochloric acid and detergents. Measurements of FEV1 and PEF taken in the evening were 174 mL (95% CI 34 to 314) and 37 L/min (CI 4 to 70), respectively, lower on days when three or more sprays were used. Evening and next morning FEV1 were both lower following the use of hydrochloric acid (-616 and -526 mL, respectively) and solvents (-751 and -1059 mL, respectively). Diurnal variation in FEV1 and PEF increased on days when ammonia and lime-scale removers were used. CONCLUSIONS: The use of specific cleaning products at work, mainly irritants and sprays, may exacerbate asthma.

Eradication Therapy against Pseudomonas aeruginosa in Non-Cystic Fibrosis Bronchiectasis.

BACKGROUND: No prospective study has assessed eradication treatment of early Pseudomonas aeruginosa colonisation in bronchiectasis not due to cystic fibrosis (CF). OBJECTIVES: To evaluate the efficacy of 3 months of nebulised tobramycin after a short course of intravenous antibiotics in the eradication of P. aeruginosa and its clinical consequences in non- CF bronchiectasis following initial P. aeruginosa infection. METHODS: A 15-month, single-masked, randomised study including 35 patients was conducted in a tertiary university hospital. Following the isolation of P. aeruginosa and a 14-day intravenous treatment with ceftazidime and tobramycin, patients received 300 mg nebulised tobramycin twice daily or placebo during 3 months, and were followed up for 12 months thereafter. RESULTS: The median time to recurrence of P. aeruginosa infection was higher in the tobramycin than in the placebo group (p = 0.048, log-rank test). At the end of the study 54.5% of the patients were free of P. aeruginosa in the tobramycin group and 29.4% in the placebo group. The numbers of exacerbations (p = 0.044), hospital admissions (p = 0.037) and days of hospitalisation (p = 0.034) were lower in the tobramycin than in the placebo group. A global, non-significant trend to improvement in the tobramycin group was observed in most of the other studied parameters on comparing the two groups. Bronchospasm in the tobramycin group was remarkable. CONCLUSIONS: Our study shows that 3 months of nebulised tobramycin following a short course of intravenous antibiotics may prevent bronchial infection with P. aeruginosa and has a favourable clinical impact on non-CF bronchiectasis.

Pleural mesothelioma in relation to meteorological conditions and residential distance from an industrial source of asbestos.

OBJECTIVES: Few studies have focused on pleural mesothelioma and environmental exposure in individuals residing around an industrial source of asbestos. The aim of this study is to determine whether residential distance and wind conditions are related to the risk of developing pleural mesothelioma. METHODS: In this retrospective cohort study carried out in an area of Barcelona province (Catalonia, Spain), 24 environmental pleural mesothelioma cases were diagnosed between 2000 and 2009. We calculated the age-standardised incidence rate ratios of developing this disease in the population studied, taking into account the residential distance from the plant. For cases living within a 500-m radius of the plant, the geographical location in relation to the factory was also assessed. RESULTS: The incidence rate of environmental pleural mesothelioma was higher in the population living within 500 m of the plant than in those living in a radius of 500-2000 m and much higher than those living at 2000-10 000 m. The highest incidence rate ratio for pleural mesothelioma (161.9) was found in the southeast quadrant of the 500-m area, coinciding with the predominant wind direction. CONCLUSIONS: Residential distance from an industrial source of asbestos and local wind conditions have a considerable impact on the risk of developing environmental pleural mesothelioma.

Oxidative Stress and Antioxidant Therapy in Pulmonary Hypertension.

Pulmonary hypertension (PH) is a progressive disease characterized by elevated artery pressures and pulmonary vascular resistance. Underlying mechanisms comprise endothelial dysfunction, pulmonary artery remodeling and vasoconstriction. Several studies have shown evidence of the critical role of oxidative stress in PH pathophysiology. Alteration of redox homeostasis produces excessive generation of reactive oxygen species, inducing oxidative stress and the subsequent alteration of biological molecules. Exacerbations in oxidative stress production can lead to alterations in nitric oxide signaling pathways, contributing to the proliferation of pulmonary arterial endothelial cells and smooth muscle cells, inducing PH development. Recently, antioxidant therapy has been suggested as a novel therapeutic strategy for PH pathology. However, the favorable outcomes observed in preclinical studies have not been consistently reproduced in clinical practice. Therefore, targeting oxidative stress as a therapeutic intervention for PH is an area that is still being explored. This review summarizes the contribution of oxidative stress to the pathogenesis of the different types of PH and suggests antioxidant therapy as a promising strategy for PH treatment.

Occupational risk factors for hand dermatitis among professional cleaners in Spain.

BACKGROUND: Dermatitis is an important health outcome for workers whose jobs put them in contact with irritants or sensitizing agents. OBJECTIVES: We conducted an analysis of data from the Epidemiological Study on the Risk of Asthma in Cleaning Workers 2 (EPIASLI2) to assess worksites and cleaning products as risk factors for hand dermatitis among professional cleaning workers. MATERIALS/METHODS: We distributed 4993 questionnaires to employees of 37 cleaning companies, and used data from 818 (16%) respondents who provided information about skin symptoms and cleaning-related exposures. We assessed associations between the frequencies of worksite and cleaning product exposures and a symptom-based definition of hand dermatitis among current cleaning workers (n = 693) and a comparison population (n = 125). RESULTS: Hand dermatitis was reported by 28% of current cleaning workers, versus 18% of the comparison population, and was associated with cleaning outdoor areas and schools, and the use of hydrochloric acid [prevalence ratio (PR) 1.92, 95% confidence interval (CI) 1.22-3.02] and dust mop products (PR 1.75, 95% CI 1.11-2.75). CONCLUSIONS: Professional cleaning workers may not be sufficiently protected from cutaneous disease at work. Future research should further investigate the roles of multiple product exposures and personal protective equipment.

Endothelial Dysfunction and Cardiovascular Risk in Obstructive Sleep Apnea: A Review Article.

Obstructive sleep apnea (OSA) is a respiratory condition during sleep caused by repeated pauses in breathing due to upper airway obstruction. It is estimated that OSA affects 30% of the population, but only 10% are well diagnosed due to the absence of a well-defined symptomatology and poor screening tools for early diagnosis. OSA is associated to an endothelial dysfunction inducing several biological responses such as hypoxia, hypercapnia and oxidative stress, among others. OSA also triggers respiratory, nervous, metabolic, humoral and immunity system activations that increase the possibility of suffering a cardiovascular (CV) disease. In this review, we expose different studies that show the relationship between OSA and endothelial dysfunction and its association with CV pathologies like hypertension, and we define the most well-known treatments and their limitations. Additionally, we describe the potential future directions in OSA research, and we report clinical features such as endothelial progenitor cell alterations that could act as biomarkers for the development of new diagnostic tools and target therapies.

Post-COVID-19 patients show an increased endothelial progenitor cell production.

SARS-CoV-2, the cause of COVID-19, has generated a global emergency. The endothelium is a target of SARS-CoV-2, generating endothelial dysfunction, an essential step for the development of cardiovascular complications. The number of endothelial progenitor cells acts as an indicator of vascular damage. However, its role in SARS-CoV-2 is unknown. The aim of this study was to quantify the number of endothelial colony forming cells (ECFCs) and assess for the first time if there is a significant increase after SARS-CoV-2 infection. This study also evaluates whether the number of ECFC is related to the presence of pulmonary embolism (PE), and if this increase correlates with any of the clinical parameters studied. A total of 63 subjects were recruited including 32 subjects 3-months after overcoming COVID-19 and 31 healthy controls. The results confirm the presence of vascular sequelae in post-COVID-19 patients, with an abnormal increase in the number of ECFCs in blood circulation compared to controls (2.81 ± 2.33 vs 1.23 ± 1.86, P = 0.001). There was no difference in ECFC production in COVID-19 who presented acute PE compared to those that did not (3.21 ± 2.49 vs 2.50 ± 2.23, P > 0.05). The appearance of ECFC colonies in COVID-19 patients was significantly related to male gender (P = 0.003), the presence of systemic hypertension (P = 0.01) and elevated hemoglobin levels (P = 0.02) at the time of ECFC isolation and lower PaO2 levels (P = 0.01) at admission. Whether these results indicate a prompt response of the patient to repair the damaged endothelium or reflect a postinfection injury that will persist in time is not known.

Individuals With SARS-CoV-2 Infection During the First and Second Waves in Catalonia, Spain: Retrospective Observational Study Using Daily Updated Data.

BACKGROUND: A description of individuals with SARS-CoV-2 infection comparing the first and second waves could help adapt health services to manage this highly transmissible infection. OBJECTIVE: We aimed to describe the epidemiology of individuals with suspected SARS-CoV-2 infection, and the characteristics of patients with a positive test comparing the first and second waves in Catalonia, Spain. METHODS: This study had 2 stages. First, we analyzed daily updated data on SARS-CoV-2 infection in individuals from Girona (Catalonia). Second, we compared 2 retrospective cohorts of patients with a positive reverse-transcription polymerase chain reaction or rapid antigen test for SARS-CoV-2. The severity of patients with a positive test was defined by their admission to hospital, admission to intermediate respiratory care, admission to the intensive care unit, or death. The first wave was from March 1, 2020, to June 24, 2020, and the second wave was from June 25, 2020, to December 8, 2020. RESULTS: The numbers of tests and cases were lower in the first wave than in the second wave (26,096 tests and 3140 cases in the first wave versus 140,332 tests and 11,800 cases in the second wave), but the percentage of positive results was higher in the first wave than in the second wave (12.0% versus 8.4%). Among individuals with a positive diagnostic test, 818 needed hospitalization in the first wave and 680 in the second; however, the percentage of hospitalized individuals was higher in the first wave than in the second wave (26.1% versus 5.8%). The group that was not admitted to hospital included older people and those with a higher percentage of comorbidities in the first wave, whereas the characteristics of the groups admitted to hospital were more alike. CONCLUSIONS: Screening systems for SARS-CoV-2 infection were scarce during the first wave, but were more adequate during the second wave, reflecting the usefulness of surveillance systems to detect a high number of asymptomatic infected individuals and their contacts, to help control this pandemic. The characteristics of individuals with SARS-CoV-2 infection in the first and second waves differed substantially; individuals in the first wave were older and had a worse health condition.

A workforce-based study of occupational exposures and asthma symptoms in cleaning workers.

OBJECTIVES: To study associations between use of cleaning products and asthma symptoms in cleaning workers. METHODS: Information on respiratory symptoms, history of asthma, workplaces, use of cleaning products and acute inhalation incidents were obtained through a self-administered questionnaire. 917 employees of 37 cleaning companies in Barcelona were studied. 761 (83%) were current cleaners, 86 (9%) former cleaners and 70 (8%) had never worked as cleaners. Multivariable logistic regression analyses were used to evaluate the associations between specific exposures among current cleaners and wheeze without having a cold, chronic cough and current asthma. Associations with an asthma symptom score were also studied using negative binomial regression analyses to report mean ratios. RESULTS: After adjusting for sex, age, nationality and smoking status, the prevalence of current asthma was non-significantly higher among current (OR 1.9; 95% CI 0.5 to 7.8) and former cleaners (OR 1.9; CI 0.6 to 5.5) than in never cleaners. Cleaners working in hospitals during the last year had a significantly increased prevalence of wheeze, current asthma and a 1.8 (95% CI 1.2 to 2.8) times higher mean asthma score. Use of hydrochloric acid was strongly associated with asthma score (mean ratio 1.7; 95% CI 1.1 to 2.6). Use of ammonia, degreasers, multiple purpose products and waxes was also associated with asthma score. CONCLUSIONS: Cleaning work in places with high demand for disinfection, high cleaning standards and use of cleaning products containing respiratory irritants is associated with higher risk of asthma symptoms. This suggests irritants have an important role in cleaning-related asthma.

Prospective study of asbestos-related diseases incidence cases in primary health care in an area of Barcelona province.

BACKGROUND: Asbestos related diseases include a number of conditions due to inhalation of asbestos fibres at work, at home or in the environment, such as pleural mesothelioma, asbestosis and calcified pleural plaques. Few epidemiological studies have established the incidence of asbestos related diseases in our area. The present proposal is based on a retrospective study externally funded in 2005 that is currently taking place in the same area and largely carried out by the same research team.The aim of the study is to achieve a comprehensive and coordinated detection of all new cases of Asbestos Related Diseases presenting to primary care practitioners. METHODS/DESIGN: This is a multicentre, multidisciplinary and pluri-institutional prospective study.Setting12 municipalities in the Barcelona province within the catchment area of the health facilities that participate in the study.SampleThis is a population based study, of all patients presenting with diseases caused by asbestos in the study area.MeasurementsA clinical and epidemiological questionnaire will be filled in by the trained researchers after interviewing the patients and examining their clinical reports. DISCUSSION: Data on the incidence of the different Asbestos Related Diseases in this area will be obtained and the most plausible exposure source and space-time-patient profile will be described. The study will also improve the standardization of patient management, the coordination between health care institutions and the development of preventive activities related with asbestos exposure and disease.

Reported occupational respiratory diseases in three Spanish regions.

BACKGROUND: In 2002, a voluntary registry of occupational respiratory diseases was initiated in the test phase in Asturias, Catalonia, and Navarre (Spain). Based on data from the fully implemented voluntary registry, we assessed the differences in the incidence and characteristics of the diseases reported in the three regions studied and compared them with those notified to the compulsory official system. METHODS: Physicians whose daily practice includes patients with occupational respiratory diseases were invited to participate. Newly diagnosed cases occurring during 2003 in the work force of the three regions studied were reported on a notification form every 2 months. Data from the compulsory official notification system were obtained from statistics on work-related diseases for possible disability benefits. RESULTS: Five hundred thirty-three new cases, representing a cumulative incidence of 183.52 (168.27-199.78) per million workers per year, were reported. The number of cases and the incidence, overall and for each disease, causes of the diseases, and the occupations varied considerably between regions. The number of cases reported to the voluntary system was more than threefold greater than the number reported to the compulsory official system. CONCLUSIONS: The compulsory scheme for reporting occupational respiratory diseases is seriously under-reporting in the three Spanish regions studied. Our voluntary surveillance program, which showed considerable differences in the characteristics and incidence of these diseases among the regions, appears to be more effective.

[Course of bronchial hyperresponsiveness in patients with occupational asthma caused by exposure to persulfate salts]. / Evolución de la hiperrespuesta bronquial en pacientes con asma ocupacional por exposición a sales de persulfato.

OBJECTIVE: Persulfate salts are among the most frequently implicated causes of occupational asthma. The aim of this study was to describe the course of bronchial hyperresponsiveness and immunologic test results in patients with occupational asthma due to persulfate salts. PATIENTS AND METHODS: Ten patients with occupational asthma due to persulfate salts were studied. Diagnosis was based on specific bronchial challenge tests performed at least 3 years before enrollment. An exhaustive medical and work history was taken during interviews with all patients, and all underwent spirometry and nonspecific bronchial challenge testing. Total immunoglobulin E levels were determined and skin prick tests to several persulfate salts were performed. RESULTS: At the time of evaluation, 7 patients had avoided workplace exposure to persulfate salts. The bronchial hyperresponsiveness of 3 of those 7 patients had improved significantly. No improvement was observed in patients who continued to be exposed. Specific skin prick tests became negative in 3 patients who were no longer exposed at the time of the follow-up evaluation. Most of the patients continued to report symptoms, although improvements were noted. One patient, however, reported worsening of symptoms in spite of avoidance of exposure. CONCLUSIONS: Although asthma symptoms and bronchial hyperresponsiveness may persist for patients with occupational asthma due to persulfate salts, their condition seems to improve if they avoid exposure. This course does not seem to differ from that reported for other cases of occupational asthma.

Risk Factors of Mortality from All Asbestos-Related Diseases: A Competing Risk Analysis.

BACKGROUND: The mortality from all malignant and nonmalignant asbestos-related diseases remains unknown. The authors assessed the incidence and risk factors for all asbestos-related deaths. METHODS: The sample included 544 patients from an asbestos-exposed community in the area of Barcelona (Spain), between Jan 1, 1970, and Dec 31, 2006. Competing risk regression through a subdistribution hazard analysis was used to estimate risk factors for the outcomes. RESULTS: Asbestos-related deaths were observed in 167 (30.7%) patients and 57.5% of these deaths were caused by some type of mesothelioma. The incidence rate after diagnosis was 3,600 per 100,000 person-years. In 7.5% of patients death was non-asbestos-related, while pleural and peritoneal mesothelioma were identified in 87 (16.0%) and 18 (3.3%) patients, respectively. CONCLUSIONS: Age, sex, household exposure, cumulative nonmalignant asbestos-related disease, and single malignant pathology were identified as risk factors for asbestos-related death. These findings suggest the need to develop a preventive approach to the community and to improve the clinical follow-up process of these patients.

Radiologically recognized pleural changes in nonpneumoconiotic silica-exposed coal miners.

OBJECTIVES: Whether nonpneumoconiotic silica-exposed coal miners develop radiologically recognizable pleural changes was studied. METHODS: In a retrospective follow-up study, the oldest and the most recent chest X-rays of 765 workers with a profusion category lower than 1/0 according to the International Labour Office were read. RESULTS: Altogether 720 (94.1%) workers had no abnormalities, and 45 (5.9%) showed some pleural alteration in the first X-ray. In 43 (6%) of the 720 with no initial abnormalities, some pleural change was detected in the last X-ray. There was a statistical difference (P = 0.022) according to silica exposure category [low: 5 (2.4%); medium: 8 (6%); high: 30 (8%)]. The relative risk for any pleural alteration was significantly increased in relation to the silica-exposed group [medium: odds ratio (OR) 5.72, 95% confidence interval (95% CI) 1.4-23.5, P = 0.016; high: OR 7.62, 95% CI 2.1-27.2, P = 0.002] and to rib alterations (OR 3.74, 95% CI 1.4-9.7, P = 0.007). In 19 (2.6%) workers with no alterations initially, a costophrenic sinus alteration was detected later. Again the silica exposure categories [low: 1 (0.5%); medium: 3 (2.2%); high: 15 (4.2%)] differed significantly (P = 0.033). The relative risk of costophrenic sinus obliteration was significantly increased in relation to the silica-exposed group [medium: OR 8.59, 95% CI 0.7-113, P = 0.102; high: OR 16.44, 95% CI 1.5-177, P = 0.021]. The appearance of two costophrenic sinus obliterations and the disappearance of four were detected in the last chest X-ray of the 45 workers with some pleural alteration initially. CONCLUSIONS: Costophrenic sinus obliteration can be found in nonpneumoconiotic silica-exposed coal miners and seems to be associated with silica exposure intensity.

Occupational asthma due to persulfate salts: diagnosis and follow-up.

BACKGROUND: Persulfate salts have been identified as a cause of occupational asthma (OA). The aim of the present study was to describe the clinical characteristics, diagnostic testing results, and follow-up of eight patients with OA that was triggered by these chemical compounds. METHODS: Eight patients with OA due to exposure to persulfate salts were studied. Immunologic, lung function, and specific bronchial challenge tests (SBCTs) were performed in all patients. Once their condition had been diagnosed, the patients were seen every 1, 3, and 6 months for a mean duration of 18 months. RESULTS: The mean time of exposure to persulfate salts up to diagnosis was 15 years (range, 3 to 27 years), and mean time that had elapsed between symptom onset and diagnosis was 38 months (range, 3 to 120 months). Three patients were smokers, six patients presented with rhinitis prior to asthma in relation to persulfate exposure, and three presented with dermatitis. The results of total IgE tests were positive in six patients, and the results of skin-prick tests for detection of persulfate salts were positive in five of these patients. The results of a SBCT was positive in the seven patients in whom it was performed. Symptoms persisted in all but one patient and required medical treatment. CONCLUSIONS: The results suggest that the reliable diagnosis of OA due to persulfate salts must be based on the specific challenge test until further experience has been acquired. Despite avoiding exposure, patients continued with symptoms and required treatment for the control of symptoms. Finally, a dependent IgE mechanism appears to be implicated in the pathogenesis of OA due to exposure to persulfate salts.