A novel cause for bronchiolitis obliterans organizing pneumonia: exposure to paint aerosols in textile workshops

Safety of 0.5% hydrogen peroxide mist used in the disinfection gateway for COVID-19

Hydrogen peroxide (H2O2) is a reactive chemical used in a wide range of applications. Most importantly, it is used for sterilization process in health care environment. In the present study, safety assessment of 0.5% of H2O2 and its mist intended to be used in the disinfection gateway for COVID-19 was evaluated. Skin irritation and repeated-dose inhalation toxicity studies were carried out in rabbits and rats, respectively. In Skin irritation study, New Zealand white rabbits were exposed topically with 0.5% H2O2 solution and observed for 24 h, 48 h, and 72 h. For repeated-dose inhalation toxicity study, Wistar rats (both male and female) were exposed (whole body exposure) to 0.5% of H2O2 mist, at a concentration of 11.022 (low dose-2-min exposure), 22.044 (medium dose-4-min exposure), and 55.11mg/kg (high dose/high dose recovery-10-min exposure) body weight, daily for 7 days. Rats in the high-dose recovery group (55.11mg/kg-10-min exposure) were kept for another 7 days without any exposure. A toxicological evaluation was done based on general health parameters, hematology, serum biochemistry, gross necropsy, and histopathological data. The results of the study indicated that there was no skin irritation potential induced on exposure of 0.5% of H2O2 to rabbits. Similarly, the inhalation toxicity of 0.5% of H2O2 mist imparts no evidence of hematological, biochemical, gross pathology, or histopathological abnormalities in rats. Further, at the laboratory condition stimulated, the NOEL was found to be 55.11mg/kg body weight. Hence, the present study concluded that 0.5% H2O2 or its mist used in the disinfection gateway for COVID-19 failed to induce any skin irritation in rabbits or inhalation toxicity in rats. Graphical abstract.

Analysis of the clinical characteristics of 176 patients with pathologically confirmed cryptogenic organizing pneumonia

Background

Cryptogenic organizing pneumonia (COP), is a form of idiopathic interstitial pneumonia (IIP) and is diagnosed by clinical-radiologic-pathologic (CRP) diagnosis. To summarize the clinical, imaging, pathological, and prognostic characteristics of 176 patients with confirmed COP.

Methods

Patients who were diagnosed with organizing pneumonia (OP) by lung biopsy between January 1, 2000, and December 31, 2013, in our hospital were retrospectively analyzed and followed up until 12/31/2017. COP was confirmed by CRP diagnosis.

Results

A total of 1,346 OP cases were identified including 1,170 (86.9%) secondary OP cases (31 cases were originally misdiagnosed as COP but later confirmed as secondary OP during follow-up) and 176 (13.1%) cases of COP. The 176 patients with COP presented with no specific clinical symptoms and chest CT revealed diverse imaging features, such as patchy ground-glass opacity (112/176, 63.6%), consolidation (100/176, 56.8%), nodules (70/176, 39.8%), and fibrous stripes (69/176, 39.2%). The majority of patients (65.3%, 115/176) presented mixed patterns, and 12 (6.8%) showed a reversed halo sign. Of the 176 patients, 83 patients had unilateral lesions (ULs) and did not undergo glucocorticoid therapy. Of the 93 patients with bilateral lesions (BLs), 3 underwent complete resection and were radically cured. The other 90 patients underwent partial resection; of these patients, 37 cases achieved spontaneous remission, and 53 were treated with glucocorticoid therapy. After steroid therapy was reduced or stopped, 35 (66%) patients experienced recurrence. Overall, the 5-year survival rate for the COP patients in our study was 98.3%.

Conclusions

Our study showed that the majority of the patients pathologically diagnosed as OP had secondary OP (86.9%), with COP accounting for only 13.9% of cases. CRP diagnosis and continuous follow-up may be the key for the accurate diagnosis of COP.

Pneumoconiosis Caused by Inhalation of Metallic Titanium Grindings

A 61-year-old man was referred to our hospital with dyspnea and an abnormal lung shadow. His occupational history, pathological findings, and an elemental analysis led to a definitive diagnosis of pneumoconiosis induced by titanium grindings. The patient experienced gradual improvement solely by avoiding titanium grindings. Titanium-induced lung disease is very rare, and most of these cases are caused by inhalation of titanium dioxide (TiO₂), which is included in a wide range of commercially available products, such as paints, pigments, and cosmetics. However, industrial workers can also develop lung diseases due to the inhalation of metallic titanium materials during metal grinding.

Preliminary results of toxicity studies in rats following low-dose and short-term exposure to methyl mercaptan

The present study was carried out to evaluate the hematotoxicity and respiratory toxicity of methyl mercaptan in Sprague-Dawley rats. A dynamic exposure methodology was adopted in this study following 7 days of exposure by repeated inhalation. The concentration of methyl mercaptan used in the exposure was 0.5 ppm and the exposure time was 6 h/day for 7 days. After exposure, the rats were sacrificed to collect lung tissue and blood samples. Routine blood and serum biochemistry were conducted. Morphological injury of lung tissue was detected by hematoxylin and eosin staining. Decreased food consumption and body weight gain in both sexes were noted in the exposure group compared with the control group. Several significant changes in hematological parameters were observed. The results showed that the blood urea nitrogen (UREA) levels and superoxide dismutase (SOD) values were significantly decreased in exposed male rats. Malondialdehyde (MDA) in lung tissue was significantly increased in both males and females in the exposed group. In the histopathological examination of lung tissue, terminal bronchiole constriction, alveolar congestion, and erythrocyte exudation were observed, suggesting that the lungs may be target organs after inhaling methyl mercaptan and workers exposed to this concentration may cause some pulmonary stimulation and injury.

28-day inhalation toxicity of 3-methoxybutyl chloroformate in rats

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3-MBCF up to 6 ppm induced mortality in 28-day inhalation study of rats.

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The NOAEL of 3-MBCF in 28 day inhalation toxicity study, was less than 3 ppm.

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3-MBCF under 12 ppm did not induce micronucleus formation in the bone marrow of rats.

The 28-day repeated inhalation study was applied for hazard assessment of 3-methoxybutyl chloroformate (3-MBCF) in Sprague Dawley rats. Groups of five rats per sex were exposed 6 h/day, 5 days per week for 4 weeks to test substance concentration (ranging from 3 to 12 ppm) using a whole-body exposure system. At the terminal sacrifice, following blood collection and gross pathological examination, organ weights were determined and fixed organs were examined. The micronucleus test was performed using bone marrow cells. Exposure of 3-MBCF induced mortality at concentrations above 6 ppm. Decreases in body weight and food intake, hematologic alterations, organ weight changes, and gross and microscopic findings were seen even at the lowest concentrations of 3 ppm. Histopathology revealed principal test substance exposure correlated with lesions in the respiratory tract in both male and female rats above 3 ppm. Groups of male rats exposed above 6 ppm show microscopic lesions in spleens, livers, testes and epididymides; however, the micronucleated polychromatic erythrocytes frequency in bone marrow cells was not changed. Based on histopathology of the respiratory tract and other organs, the no observed adverse effect level (NOAEL) of 3-MBCF in the present study was less than 3 ppm.

Two Cases of Tsunami Dust Pneumonia: Organizing Pneumonia Caused by the Inhalation of Dried Tsunami Sludge after the 2011 Great East Japan Earthquake

We report two cases of organizing pneumonia (OP) secondary to the inhalation of the dried tsunami sludge which formed during the 2011 Great East Japan Earthquake and the consequent tsunami. After the disaster, both of these patients had been engaged in the restoration work. About half a month later, they developed shortness of breath and pulmonary infiltrates. These patients were diagnosed with interstitial pneumonia. Their biopsy specimens revealed multifocal peribronchiolitis and OP. An electron probe microanalysis of these specimens demonstrated the presence of elements from the earth's crust in the inflammatory lesions. These two cases indicate that exposure to dried tsunami sludge can cause OP.

Occupational and environmental bronchiolar disorders

Occupational and environmental causes of bronchiolar disorders are recognized on the basis of case reports, case series, and, less commonly, epidemiologic investigations. Pathology may be limited to the bronchioles or also involve other components of the respiratory tract, including the alveoli. A range of clinical, functional, and radiographic findings, including symptomatic disease lacking abnormalities on noninvasive testing, poses a diagnostic challenge and highlights the value of surgical biopsy. Disease clusters in workplaces and communities have identified new etiologies, drawn attention to indolent disease that may otherwise have been categorized as idiopathic, and expanded the spectrum of histopathologic responses to an exposure. More sensitive noninvasive diagnostic tools, evidence-based therapies, and ongoing epidemiologic investigation of at-risk populations are needed to identify, treat, and prevent exposure-related bronchiolar disorders.

Acute and subacute chemical-induced lung injuries: HRCT findings

Lung injury caused by chemicals includes bronchitis, bronchiolitis, chemical pneumonitis, pulmonary edema, acute respiratory distress syndrome, organizing pneumonia, hypersensitivity pneumonitis, acute eosinophilic pneumonia, and sarcoid-like granulomatous lung disease. Each chemical induces variable pathophysiology and the situation resembles to the drug induced lung disease. The HRCT features are variable and nonspecific, however HRCT may be useful in the evaluation of the lung injuries and so we should know about HRCT features of lung parenchymal abnormalities caused by chemicals.

Bronchiolitis obliterans organizing pneumonia, 25 years: a variety of causes, but what are the treatment options?

Bronchiolitis obliterans organizing pneumonia is an inflammatory lung disease involving the distal bronchioles, respiratory bronchioles, bronchiolar ducts and alveoli. Its cause is generally unknown, but there are several known causes and associated systemic diseases. The clinical features include cough, shortness of breath and bilateral crackles. The vital capacity is slightly decreased, and the diffusing capacity is moderately to severely decreased. The high-resolution chest CT scan shows bilateral ground-glass opacities with air bronchograms and triangular, pleura-based opacities. Corticosteroid therapy is the best treatment option. The outcome of patients suffering from bronchiolitis obliterans organizing pneumonia is good, as up to 80% of individuals will be cured.

Bronchiolitis obliterans organizing pneumonia: pathogenesis, clinical features, imaging and therapy review

Bronchiolitis obliterans organizing pneumonia (BOOP) was first described in the early 1980s as a clinicopathologic syndrome characterized symptomatically by subacute or chronic respiratory illness and histopathologically by the presence of granulation tissue in the bronchiolar lumen, alveolar ducts and some alveoli, associated with a variable degree of interstitial and airspace infiltration by mononuclear cells and foamy macrophages. Persons of all ages can be affected. Dry cough and shortness of breath of 2 weeks to 2 months in duration usually characterizes BOOP. Symptoms persist despite antibiotic therapy. On imaging, air space consolidation can be indistinguishable from chronic eosinophilic pneumonia (CEP), interstitial pneumonitis (acute, nonspecific and usual interstitial pneumonitis, neoplasm, inflammation and infection). The definitive diagnosis is achieved by tissue biopsy. Patients with BOOP respond favorably to treatment with steroids.

Uncommon occupational lung diseases: high-resolution CT findings

OBJECTIVE

The purpose of this article is to describe the high-resolution CT (HRCT) features of uncommon occupational lung diseases.

CONCLUSION

HRCT plays an increasing role in the evaluation of occupational lung diseases. We present several cases of unusual occupational lung diseases and their HRCT findings. The diseases studied were siderosis, talcosis, berylliosis, calcicosis, hypersensitivity pneumonitis (due to wheat flour and isocyanates), and Ardystil syndrome. The characteristic HRCT findings together with clinical features and related occupational history improve the diagnostic accuracy of these diseases.

Occupational asthma due to acrylates in a graphic arts worker

BACKGROUND

Acrylates are used in a wide variety of products such as solvents, adhesives, paints, printing ink, soft contact lenses, porcelain nails, and methacrylates (used by dentists and orthopedists). Currently there are various types of acrylic compounds: acrylates, cyanoacrylates (such as tissue adhesives and home glues), and methacrylates (prostheses and dental and orthopedic fillings). The sensitization mechanism is unknown, but the allergy is believed to be due to a non-IgE mediated phenomenon, since a late asthmatic response occurs. Various cases of acrylate-induced asthma have been reported, especially in dentists and persons using glues or paints containing this substance.

MATERIAL AND METHODS

We present the case of a 52-year-old man who had been working in graphic arts for the previous 7 years. For the previous 2 years he had experienced persistent cough with a sensation of drowning, dyspnea that increased with moderate exertion, and nasal obstruction despite continuous treatment. The symptoms first appeared after an episode of acute respiratory difficulty associated with weight loss, pulmonary infiltrates, and eosinophilia. Peak expiratory flow (PEF) was measured during work and sick leave, and specific bronchial challenge with acrylates was performed in a bronchial chamber.

RESULTS

The PEF improved on weekends and sick leave. The challenge test provoked a late asthmatic response and the non-specific bronchial hyperreactivity increased after the test. As well in the sputum samples there was a increase of eosinophil amount.

Methods for estimating the transfer efficiency of a compressed air spray gun

The transfer efficiency of a compressed air spray gun is an important performance index with regard to worker health, environmental, and economic considerations. It is defined as the fraction of paint sprayed that coats the surface. Worker exposure has been identified as a function of the transfer efficiency based on total mass of paint sprayed, which can be predicted by a mathematical model developed with nonvolatile oil. This study extends the existing model to include volatile effects by employing a mathematical approach based on a mass balance. This method allows the current model to predict transfer efficiency bounds at two extreme situations: all volatile compounds evaporate either before or after droplet impaction. Model predictions show that tight transfer efficiency bounds are obtained, especially for high values of transfer efficiency. Thus, the average of the upper and lower bounds should be a reasonable estimate of transfer efficiency. It is also found that the current model prediction, which is based on total mass of paint sprayed, for nonvolatile material can be converted to a transfer efficiency based on the mass of solids. The laboratory study shows that the predicted transfer efficiency based on the mass of solids is within the 95 percent C.I. of the measured value. This work relates the transfer efficiency used in industry, which is calculated on the basis of paint solids, with a model that predicts worker exposure during spray painting operations.

Polyanions protect against the in vitro pulmonary toxicity of polycationic paint components associated with the Ardystil syndrome

The polycationic paint components of the Acramin F system have led to severe pulmonary disease in textile printing sprayers in Spain and Algeria (Ardystil syndrome). In order to elucidate the underlying mechanisms of the toxicity of these nitrogen-containing polymeric paint components, Acramin FWR (FWR), Acramin FWN (FWN), and Acrafix FHN (FHN), we have studied the effect of coincubation with polyanionic compounds, Sulodexide (heparin-like substance), DNA and poly-l-glutamic acid (of different lengths) in different pulmonary cell types. This study shows that the cytotoxicity of the three polycationic paint components FWR (a polyurea), FWN (a polyamide-amine), and FHN (a polyamine) is markedly decreased in the presence of the polyanions. It is concluded that the paint components FWR, FWN, and FHN execute their cytotoxicity at least partly by the abundant positive charges these molecules carry at physiological pH.

Inhalation studies in laboratory animals--current concepts and alternatives

Highly standardized and controlled inhalation studies are required for hazard identification to make test results reproducible and comparable and to fulfill general regulatory requirements for the registration of new drugs, pesticides, or chemicals. Despite significant efforts, the results of inhalation studies have to be analyzed judiciously due to the great number of variables. These variables may be related to technical issues or to the specific features of the animal model. Although inhalation exposure of animals mimics human exposure best, ie, error-prone route-to-route extrapolations are not necessary, not all results obtained under such very rigorous test conditions may necessarily also occur under real-life exposure conditions. Attempts are often made to duplicate as closely as possible these real-life exposure conditions of humans in appropriate bioassays. However, this in turn might affect established baseline data, rendering the interpretation of new findings difficult. In addition, specific use patterns, eg, of inhalation pharmaceuticals or pesticide-containing consumer products, may impose test agent-specific constraints that challenge traditional approaches. Moreover, specific modes of action of the substance under investigation, the evaluation of specific endpoints, or the clarification of equivocal findings in common rodent species may require exposure paradigms or the use of animal species not commonly used in inhalation toxicology. However, particularly in inhalation toxicology, the choice of animal models for inhalation toxicity testing is usually based on guideline requirements and practical considerations, such as exposure technology, expediency, and previous experience rather than validity for use in human beings. Larger animal species, apart from the welfare aspects, may require larger inhalation chambers to accommodate the animals, but for technical reasons and the difficulty of generating homogeneous exposure atmospheres in such inhalation chambers, this may jeopardize the outcome of the study. Some of the many variables and possible artifacts likely to occur in animal inhalation studies are addressed in this paper.

Repeated pulmonary function measurements in rats after intratracheal instillation of a polyamine textile pigment component

The pulmonary response of Wistar rats to a cumulative dose of 1 mg/kg body weight of a polymeric alpha,omega-diamine was examined using the intratracheal route of administration. Instillation of the test substance was on days 0 and 7 followed by a 3-month postobservation period. Static and dynamic pulmonary function tests, including arterial blood gas determinations, were performed during wk 5, 9, and 13. At all time points, significantly depressed flow-volume curves, reduced quasistatic compliance, and reduced vital capacity were observed. These were associated with increases of residual volume and functional residual capacity in the presence of unremarkable changes of total lung capacity (TLC). One of the most predominant dysfunctions of the lung was a severe maldistribution of ventilation, indicated by the single-breath nitrogen washout test. The carbon monoxide diffusing capacity (DL(CO)), in turn, was only mildly decreased, and differences between treatment and control groups did not reach statistical significance. Assessment of arterial blood gases demonstrated a statistically significantly increased venous admixture with subsequent slight hypoxemia. In summary, the predominant dysfunction appeared to be consistent with an obstructive rather than restrictive lung disease. The functional changes observed may account for the effect on arterial blood gases, suggesting a mismatch of the ventilation-perfusion relationship. Either measurement appear to demonstrate a relative stable dysfunction during the 3-mo postinstillation observation period. Collectively, this study supports the view held that polymeric alpha, omega-diamines appear to be potent pneumotoxicants.

Bronchiolitis obliterans-organizing pneumonia: an Italian experience

The purpose of this study was to describe the clinical features at onset and outcome and the diagnostic approach in subjects with bronchiolitis obliterans-organizing pneumonia (BOOP). Over a 7-year period we observed 78 cases of biopsy-proven bronchiolitis obliterans-organizing pneumonia, in which well documented clinical and radiographic data were available. The final diagnosis of BOOP was validated when patients presented: (i) negative microbiological analysis on BAL fluid; (ii) a well documented improvement either spontaneous, or after steroid treatment or (iii) cases with progressive respiratory failure and increasing radiographic shadows, an open lung biopsy or autopsy that excluded other entities. There were 42 males and 36 females; the mean age was 61+/-12 years (range 12-85 years). Forty-two (54%) patients were current smokers, 25 (32%) had never smoked and 11 (14%) were ex-smokers. The clinical pattern at presentation of BOOP was more frequently similar to classical acute or sub-acute infectious pneumonia. Fever (63%), dyspnoea (58%) and dry cough (53%) were the typical symptoms on admission. A flu-like syndrome preceeding BOOP was observed in 21 cases (27%). Inspiratory crackles (78%) were the most typical finding at physical examination. However, 13% of the patients were asymptomatic and an abnormal chest X-ray film was the reason for seeking medical attention. Radiographically the most frequent pattern of BOOP was a unilateral consolidation (44%) with lower field predominance. A migratory behaviour was present in 22% of the cases. High-resolution computed tomographic (HR-CT) scan when performed, was more sensitive in detecting ground glass infiltrates, sub-pleural or peri-bronchovascular distribution or the presence of nodules or cavitation. Most patients (68%) were classified as having idiopathic BOOP. However, the same clinical-roentgenological pattern was observed in patients after radiotherapy for ductal breast carcinoma (6%), in collagen-vascular diseases (6%), related to drugs (9%), to infections serologically documented (4%), and to graft vs. host disease (4%). Four patients (all of whom had idiopathic BOOP) presented a rapid progressive respiratory failure needing mechanical ventilation. In another two cases respiratory failure appeared after a long period during which patients experienced exertional dyspnoea and low grade fever. BAL profile was characterized by lymphocytosis with a reduction of the CD4/CD8 ratio, associated with a slight increase of neutrophils and eosinophils and scattered mast cells. However in two cases we had an increased CD4/CD8 ratio and in one case the presence of a significant 12% of polyclonal B cells. In a few cases atypical (cytokeratin-positive cells) epithelial cells were detected: these cells were constantly present in the BAL fluid of patients with rapidly progressive respiratory failure. From the diagnostic point of view this series documents that transbronchial lung biopsy (coupled with BAL) can be the first diagnostic step. However, therapy can be started on the basis of BAL data (when a characteristic morphological and phenotypical profile is evident) in cases in which the clinical presentation is suggestive and a biopsy cannot be made. Most patients showed a rapid and good response to steroid therapy. However, three patients died (4%) in spite of steroid therapy (two cases) and steroid and cyclophosphamide therapy (one case). In conclusion, although clinical findings, chest X-ray film and CT Scan findings usually suggest the diagnosis a definite confirmation requires transbronchial lung biopsy and BAL and, less frequently, open lung biopsy.

The past and present of pneumoconioses

Pneumoconioses are still a common cause of chronic lung disease. In industrialized countries, improvements in working conditions and dust control measures have led to a decrease in the incidence of severe forms of silicosis, coal worker pneumoconiosis, and parenchymal asbestosis. However, the diversity of settings in which silica and asbestos are used fuels a continued input of cases, and the burden of cases related to remote exposures is still considerable. Overall, the clinical picture of the classic pneumoconioses and their complications has not changed substantially. However, their limits and links have expanded toward systemic and connective tissue disease, idiopathic pulmonary fibrosis, and antineutrophil cytoplasmic autoantibody-positive vasculitides. Immunologically mediated occupational lung diseases have emerged, such as berylliosis and hard-metal disease. Advances in imaging, mineralogic analysis of bronchoalveolar lavage fluid, and immunologic techniques have been instrumental in describing new patterns of disease and are helpful in litigious or difficult cases.