Association of man-made mineral fibre exposure and sarcoidlike granulomas

Infectious and non-infectious precipitants of sarcoidosis

Sarcoidosis is a chronic inflammatory disease that can affect any organ in the body. Its exact cause remains unknown, but it is believed to result from a combination of genetic and environmental factors. Some potential causes of sarcoidosis include genetics, environmental triggers, immune system dysfunction, the gut microbiome, sex, and race/ethnicity. Genetic mutations are associated with protection against disease progression or an increased susceptibility to more severe disease, while exposure to certain chemicals, bacteria, viruses, or allergens can trigger the formation of immune cell congregations (granulomas) in different organs. Dysfunction of the immune system, including autoimmune reactions, may also contribute. The gut microbiome and factors such as being female or having African American, Scandinavian, Irish, or Puerto Rican heritage are additional contributors to disease outcome. Recent research has suggested that certain drugs, such as anti-Programmed Death-1 (PD-1) and antibiotics such as tuberculosis (TB) drugs, may raise the risk of developing sarcoidosis. Hormone levels, particularly higher levels of estrogen and progesterone in women, have also been linked to an increased likelihood of sarcoidosis. The diagnosis of sarcoidosis involves a comprehensive assessment that includes medical history, physical examination, laboratory tests, and imaging studies. While there is no cure for sarcoidosis, the symptoms can often be effectively managed through various treatment options. Treatment may involve the use of medications, surgical interventions, or lifestyle changes. These disparate factors suggests that sarcoidosis has multiple positive and negative exacerbants on disease severity, some of which can be ameliorated and others which cannot.

Systematic review of epidemiological studies evaluating the association between exposure to man-made vitreous fibers and non-malignant respiratory diseases

This study aimed to systematically review and synthesize epidemiological evidence evaluating the association between occupational man-made vitreous fiber (MMVF) exposure and non-malignant respiratory disease (NMRD). We searched PubMed and Scopus databases to identify epidemiological studies evaluating the association between occupational MMVF exposure (limited to insulation wools) and at least 1 NMRD outcome published prior to January 2023. A total of 23 studies met our inclusion criteria. Studies of NMRD mortality among workers with MMVF exposure (n = 9) predominately reported null findings. Qualitative and quantitative synthesis of evidence from these studies suggests that MMVF exposure is not associated with elevated risk of NMRD mortality. The remaining 14 studies evaluated NMRD morbidity, specifically self-reported respiratory symptoms and/or subclinical measures of respiratory disease. Our review did not identify any consistent or compelling evidence of an association between MMVF exposure and any NMRD morbidity outcome; however, this body of evidence was largely limited by cross-sectional design, self-reported exposure and/or outcome ascertainment, incomplete statistical analysis and reporting, and questionable generalizability given that 13/14 studies were published over 20 years ago. We recommend that future studies aim to overcome the limitations of this literature to more accurately characterize the association between occupational MMVF exposure and NMRD morbidity.

The Role of Cutibacterium acnes in Sarcoidosis: From Antigen to Treatable Trait?

Cutibacterium acnes (C. acnes, formerly Propionibacterium acnes) is considered to be a non-pathogenic resident of the human skin, as well as mucosal surfaces. However, it also has been demonstrated that C. acnes plays a pathogenic role in diseases such as acne vulgaris or implant infections after orthopedic surgery. Besides a role in infectious disease, this bacterium also seems to harbor immunomodulatory effects demonstrated by studies using C. acnes to enhance anti-tumor activity in various cancers or vaccination response. Sarcoidosis is a systemic inflammatory disorder of unknown causes. Cultures of C. acnes in biopsy samples of sarcoidosis patients, its presence in BAL fluid, tissue samples as well as antibodies against this bacterium found in serum of patients with sarcoidosis suggest an etiological role in this disease. In this review we address the antigenic as well as immunomodulatory potential of C. acnes with a focus on sarcoidosis. Furthermore, a potential role for antibiotic treatment in patients with sarcoidosis will be explored.

Altered pharmacology and toxicology during ageing: implications for lung disease

PURPOSE OF REVIEW

Drug use in elderly people is high compared to younger people. Simultaneously, elderly are at greater risk when exposed to environmental substances. It is puzzling therefore, that ageing, as a variable in pharmacological and toxicological processes is not investigated in more depth. Moreover, recent data suggest that molecular manifestations of the ageing process also hallmark the pathogenesis of chronic lung diseases, which may impact pharmacology and toxicology.

RECENT FINDINGS

In particular, absorption, distribution, metabolism and excretion (ADME) processes of drugs and toxins alter because of ageing. Polypharmacy, which is quite usual with increasing age, increases the risk of drug-drug interactions. Individual differences in combination of drugs use in conjunction with individual variations in drug metabolizing enzymes can influence lung function.

SUMMARY

Exploring exposure throughout life (i.e. during ageing) to potential triggers, including polypharmacy, may avoid lung disease or unexplained cases of lung damage. Understanding of the ageing process further unravels critical features of chronic lung disease and helps to define new protective targets and therapies. Optimizing resilience can be key in pharmacology and toxicology and helps in maintaining healthy lungs for a longer period.

Chronic effects of occupational exposure to mineral fibers and recurrent chest infections in insulators

Mineral fibres, which are types of commercially produced man-made vitreous fibres (MMVFs) with a woolly consistency, are industrially manufactured by passing air through molten glass, rock or slag, and are commonly known as glass, slag or rock wool. Although all these materials are grouped together as mineral fibres, there are differences in their composition and physical properties. Glass wool/fibreglass is made from borosilicate glass, which is composed of sand, soda ash dolomite, limestone, ulexite and anhydrite, while rock and slag wools are produced from naturally occurring igneous rock (basalt or dolomite rocks) and molten furnace slag, respectively [1]. These disorganised, interlocking fibres were reported to deliver potentially deleterious health effects, particularly on the skin and upper respiratory tract, to workers occupationally exposed to these materials, such as during installation or removal of insulation [2, 3]. While a few studies reported no evidence of pneumoconiosis in the industrial workers exposed to glass, rock or slag wool [4], several case reports appeared in recent years describing a long biopersistence of MMVFs leading to the development of pulmonary fibrosis at a later stage [5–8]. However, evidence of mineral fibre-associated respiratory tract infections has been limited. In this study, we aimed to investigate whether occupational exposure to mineral fibres was associated with recurrent chest infections.

Exposure to mineral fibres (man-made forms of vitreous fibres often used as insulating material) is a risk factor for recurrent chest infections among workers, underscoring the necessity of workplace surveillance for protection from hazardous substanceshttps://bit.ly/38cUpmA

Sarcoid-like Granulomatous Lung Disease with Subacute Progression in Silicosis

A 67-year-old man was admitted to our hospital with cough and fatigue. He had had long-term exposure to silica due to cement processing. Chest computed tomography showed bilateral centrilobular nodules, and hilar and mediastinal lymphadenopathy with calcification, suggesting chronic silicosis. Within a few months, these nodules enlarged, and bilateral patchy consolidations appeared. A lung biopsy revealed sarcoid-like granulomas with birefringent particles under polarized light without malignancy or infection. He was diagnosed with silicosis-associated sarcoid-like granulomatous lung disease, rather than sarcoidosis, according to the clinicopathological findings. His pulmonary manifestations improved after the discontinuation of silica exposure and combination therapy of corticosteroid and azathioprine.

Epigenetics and sarcoidosis

Epigenetic modifications are emerging as important regulatory mechanisms of gene expression in lung disease, given that they are influenced by environmental exposures and genetic variants, and that they regulate immune and fibrotic processes. In this review, we introduce these concepts with a focus on the study of DNA methylation and histone modifications and discuss how they have been applied to lung disease, and how they can be applied to sarcoidosis. This information has implications for other exposure and immunologically mediated lung diseases, such as chronic beryllium disease, hypersensitivity pneumonitis, and asbestosis.

A Primer on the Clinical Aspects of Sarcoidosis for the Basic and Translational Scientist

The immunopathogenesis of sarcoidosis remains unclear. This failure in understanding has been clinically impactful, as it has impeded the accurate diagnosis, treatment, and prevention of this disease. Unraveling the mechanisms of sarcoidosis will require input from basic and translational scientists. In order to reach this goal, scientists must have a firm grasp of the clinical aspects of the disease, including its diagnostic criteria, the immunologic defects, clinical presentations, response to therapy, risk factors, and clinical course. This manuscript will provide an overview of the clinical aspects of sarcoidosis that are particularly relevant for the basic and translational scientist. The variable phenotypic expression of the disease will be described, which may be integral in identifying immunologic disease mechanisms that may be relevant to subgroups of sarcoidosis patients. Data concerning treatment and risk factors may yield important insights concerning germane immunologic pathways involved in the development of disease. It is hoped that this manuscript will stimulate communication between scientists and clinicians that will eventually lead to improved care of sarcoidosis patients.

Pneumoconiosis with a Sarcoid-Like Reaction Other than Beryllium Exposure: A Case Report and Literature Review

Background: Chronic beryllium disease (CBD) is a granulomatous disease that resembles sarcoidosis but is caused by beryllium. Clinical manifestations similar to those observed in CBD have occasionally been reported in exposure to dusts of other metals. However, reports describing the clinical, radiographic, and pathological findings in conditions other than beryllium-induced granulomatous lung diseases, and detailed information on mineralogical analyses of metal dusts, are limited. Case presentation: A 51-year-old Japanese man with rapidly progressing nodular shadows on chest radiography, and a 10-year occupation history of underground construction without beryllium exposure, was referred to our hospital. High-resolution computed tomography showed well-defined multiple centrilobular and perilobular nodules, and thickening of the intralobular septa in the middle and lower zones of both lungs. No extrathoracic manifestations were observed. Pathologically, the lung specimens showed 5–12 mm nodules with dust deposition and several non-necrotizing granulomas along the lymphatic routes. X-ray analytical electron microscopy of the same specimens revealed aluminum, iron, titanium, and silica deposition in the lung tissues. The patient stopped smoking and changed his occupation to avoid further dust exposure; the chest radiography shadows decreased 5 years later. Conclusion: The radiological appearances of CBD and sarcoidosis are similar, although mediastinal or hilar lymphadenopathy is less common in CBD and is usually seen in the presence of parenchymal opacities. Extrathoracic manifestations are also rare. Despite limited evidence, these findings are similar to those observed in pneumoconiosis with a sarcoid-like reaction due to exposure to dust other than of beryllium. Aluminum is frequently detected in patients with pneumoconiosis with a sarcoid-like reaction and is listed as an inorganic agent in the etiology of sarcoidosis. It was also detected in our patient and may have contributed to the etiology. Additionally, our case suggests that cessation of dust exposure may contribute to improvement under the aforementioned conditions.

Environmental Risk Factors for Sarcoidosis

Sarcoidosis is a multisystem granulomatous disease that may affect any body organ. Sarcoidosis is associated with many environmental and occupational exposures. Because the exact immunopathogenesis of sarcoidosis is unknown, it is not known whether these exposures are truly causing sarcoidosis, rendering the immune system more susceptible to the development of sarcoidosis, exacerbating subclinical cases of sarcoidosis, or causing a granulomatous condition distinct from sarcoidosis. This manuscript outlines what is known about the immunopathogenesis of sarcoidosis and postulates mechanisms whereby these exposures could cause or exacerbate the disease. We also describe the varied environmental and occupational exposures that have been associated with sarcoidosis. This includes potential infectious exposures such as mycobacteria and Propionibacterium acnes, a skin commensal bacterium, as well as non-infectious environmental exposures including inhaled bioaerosols, metal dusts and products of combustion. Further insights concerning the relationship of environmental exposures to the development of sarcoidosis may have a major impact on the prevention and treatment of this enigmatic disease.

Immunoreactivity to metal and silica associates with sarcoidosis in Dutch patients

Background

Involvement of metals or silica in the pathogenesis of sarcoidosis has been suggested by several case reports and specific epidemiological studies. However, the combination of occupational exposure and an immunological reaction has not been studied before in a group of sarcoidosis patients and non-sarcoidosis controls.

Methods

In 256 sarcoidosis patients and 73 control patients with obstructive sleep apnea, exposure to metal and silica was assessed using a questionnaire consisting of a complete occupational history subsequently linked to job-exposure matrices. Next, immunoreactivity to aluminium, beryllium, zirconium and silica was determined in 33 sarcoidosis and 19 control patients using a lymphocyte proliferation test.

Results

In sarcoidosis, 83 out 256 patients (32.4%) had occupational exposure to metals or silica, compared to 24.7% in the control group (p = 0.21). A significantly higher percentage of the sarcoidosis patients tested showed immunoreactivity to metals or silica compared to the control group (21.2 and 0% respectively, p = 0.039).

Conclusions

Immunoreactivity to silica and metals was only found in sarcoidosis patients, supporting the hypothesis that these antigens may be involved in the pathogenesis of a distinct subgroup of sarcoidosis patients. This indicates that when searching for causative agents in sarcoidosis patients, besides beryllium, also zirconium, aluminium and silica deserve clinical investigation.

New advances in the management of pulmonary sarcoidosis

Sarcoidosis is a highly variable granulomatous multisystem syndrome. It affects individuals in the prime years of life; both the frequency and severity of sarcoidosis are greater in economically disadvantaged populations. The diagnosis, assessment, and management of pulmonary sarcoidosis have evolved as new technologies and therapies have been adopted. Transbronchial needle aspiration guided by endobronchial ultrasound has replaced mediastinoscopy in many centers. Advanced imaging modalities, such as fluorodeoxyglucose positron emission tomography scanning, and the widespread availability of magnetic resonance imaging have led to more sensitive assessment of organ involvement and disease activity. Although several new insights about the pathogenesis of sarcoidosis exist, no new therapies have been specifically developed for use in the disease. The current or proposed use of immunosuppressive medications for sarcoidosis has been extrapolated from other disease states; various novel pathways are currently under investigation as therapeutic targets. Coupled with the growing recognition of corticosteroid toxicities for managing sarcoidosis, the use of corticosteroid sparing anti-sarcoidosis medications is likely to increase. Besides treatment of granulomatous inflammation, recognition and management of the non-granulomatous complications of pulmonary sarcoidosis are needed for optimal outcomes in patients with advanced disease.

Granulomatous lung disease in two workers making light bulbs

BACKGROUND

Associations between sarcoidosis or sarcoid-like granulomatous lung disease and exposure to silica and other inorganic agents have been suggested in several studies.

CASES

We describe granulomatous lung disease in two workers of a small production unit making metal-halide lamps. Initially, both were diagnosed with sarcoidosis. However, in both men, birefringent particles were observed in the lung or mediastinal lymph node biopsies. Clipping of glass tubes led to moderate exposure to dust, consisting mainly of amorphous fused silica, with some cristobalite. After removal from exposure, both subjects improved clinically, radiologically, and functionally.

CONCLUSION

The present cases support the hypothesis that silica might be a trigger for sarcoid-like granulomatous lung disease. Sarcoidosis should be considered a diagnosis of exclusion and clinicians should carefully collect occupational and environmental exposure histories to identify workplace triggers.

Sarcoidosis, inorganic dust exposure and content of bronchoalveolar lavage fluid: the MINASARC pilot study

Inhalation of mineral dust was suggested to contribute to sarcoidosis. We compared the mineral exposome of 20 sarcoidosis and 20 matched healthy subjects. Bronchoalveolar lavage (BAL) samples were treated by digestion-filtration and analyzed by transmission electron microscopy. The chemical composition of inorganic particles was determined by energy-dispersive X-ray (EDX) spectroscopy. Dust exposure was also assessed by a specific questionnaire. Eight sarcoidosis patients and five healthy volunteers had a high dust load in their BAL. No significant difference was observed between the overall inorganic particle load of each group while a significant higher load for steel was observed in sarcoidosis patients (p=0.029). Moreover, the building activity sub-score was significantly higher in sarcoidosis patients (p=0.018). These results suggest that building work could be a risk factor for sarcoidosis which could be considered at least in some cases as a granulomatosis caused by airborne inorganic dust. The questionnaire should be validated in larger studies. (Sarcoidosis Vasc Diffuse Lung Dis 2018; 35: 327-332)

Sarcoidosis in iron-steel industry: mini case series

Sarcoidosis is a disease of unknown etiology. Despite the proposed connection between the development of sarcoidosis and exposure to environmental and toxic substances, no definitive associations could be established. Also, the role of silica and silicates in the etiology of this condition is currently unknown. Heat-treatment of silica results in the generation of tridymite and cristobalite forms and iron-steel industry represents one branch of industry in which silicone element is exposed to temperatures around 2000°C. Studies reporting on the incidence of sarcoidosis in the workers of iron-steel industry are scarce in number, and workers of this industrial branch are known to be exposed to silica in the form of cristobalite, nano-particulate silicone, metal oxides, and silicates. These substances, which have respiratory toxic properties and have been reported to be associated with autoimmune conditions, may also play a role in the pathogenesis of sarcoidosis. In our clinic, sarcoidosis was diagnosed in a total of 4 individuals, who works in the iron-steel industry. Through this report involving a series of patients with sarcoidosis, we also wanted to discuss the role of crystalline silica forms and silicates in the etiology of sarcoidosis, which is also considered to be an auto-immune condition. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 365-372).

Elemental analysis of occupational granulomatous lung disease by electron probe microanalyzer with wavelength dispersive spectrometer: Two case reports

The parenchymal lung diseases caused by metal inhalation include interstitial fibrosis, giant cell interstitial pneumonitis, chemical pneumonitis, and granulomatous disease, among others. We reported two cases of granulomatous lung disease with occupational exposure to metal dusts other than beryllium. They had worked in the battery manufacturing industry for 7 years and in an aluminum-processing factory for 6 years, respectively. Chest high-resolution computed tomography showed diffuse micronodules, and histology of video-assisted lung biopsy specimens revealed granulomatous lesions in the pulmonary interstitium. Results of microscopic examination of the tissue with special stains for mycobacteria and fungi were negative. Analysis by an electron probe microanalyzer with a wavelength-dispersive spectrometer (EPMA-WDS) confirmed the presence of silicon, iron, aluminum, and titanium in the granulomas. In particular, aluminum was distributed in a relatively high concentration in the granulomatous lesions. Although chronic beryllium disease is well known as an occupational granulomatous lung disease, much less is known about the other metals that cause granulomatous reactions in humans. Our report pointed out manifestations similar to beryllium disease after other metal dust exposures, in particular aluminum exposure. To our knowledge, this is the first report showing two-dimensional images of elemental mapping in granulomatous lesions associated with metal inhalation using EPMA-WDS.

Association Between Occupational Exposures and Sarcoidosis: An Analysis From Death Certificates in the United States, 1988-1999

BACKGROUND

Sarcoidosis is a disease that is associated with occupational and environmental antigens, in the setting of a susceptible host. The aim of this study was to examine the association between sarcoidosis mortality and previously reported occupational exposures based on sex and race.

METHODS

The decedents enrolled in this study were derived from United States death certificates from 1988-1999. Cause of death was coded according to ICD-9 and ICD-10. The usual occupation was coded with Bureau of the Census Occupation Codes. Mortality odds ratio (MOR) were determined and multiple Poisson regression were performed to evaluate the independent exposure effects after adjustment for age, sex, race and other occupational exposures.

RESULTS

Of the 7,118,535 decedents in our study, 3,393 were identified as sarcoidosis-related, including 1,579 identified as sarcoidosis being the underlying cause of death. The sarcoidosis-related MOR of any occupational exposure was 1.52 (95% CI, 1.35-1.71). Women with any exposure demonstrated an increased MOR compared to women without (MOR 1.65, 95% CI, 1.45-1.89). The mortality risk was significantly elevated in those with employment involving metal working, health care, teaching, sales, banking, and administration. Higher sarcoidosis-related mortality risks associated with specific exposures were noted in women vs men and blacks vs whites.

CONCLUSIONS

Findings of prior occupations and risk of sarcoidosis were verified using sarcoidosis mortality rates. There were significant differences in risk for sarcoidosis mortality by occupational exposures based on sex and race.

Man-made mineral fibers and the respiratory tract

Man-made mineral fibers are produced using inorganic materials and are widely used as thermal and acoustic insulation. These basically include continuous fiberglass filaments, glass wool (fiberglass insulation), stone wool, slag wool and refractory ceramic fibers. Likewise, in the last two decades nanoscale fibers have also been developed, among these being carbon nanotubes with their high electrical conductivity, mechanical resistance and thermal stability. Both man-made mineral fibers and carbon nanotubes have properties that make them inhalable and potentially harmful, which have led to studies to assess their pathogenicity. The aim of this review is to analyze the knowledge that currently exists about the ability of these fibers to produce respiratory diseases.

Pathogenesis of sarcoidosis

Sarcoidosis is a systemic granulomatous disorder of unknown origin. Recent research uncovered underlying immunological and genetic mechanisms, which will pave the way for more effective pharmaceutical studies. At present some of this knowledge is clinically exploited to monitor therapy and expected genetic progress will allow the development of prognostic genetic patterns or molecular signatures. Moreover, it has become obvious that several etiologic agents and cofactors will exist. These will be of animate and inanimate nature and their interplay with host mechanisms discussed in this review determines disease phenotypes.

Tunnel excavation triggering pulmonary sarcoidosis

CONTEXT

A definite cause of sarcoidosis has not been identified, however past research suggests that environmental factors may be triggers of the granulomatous response in genetically susceptible individuals.

CASE PRESENTATION

A 22-year-old male non-smoker, presented with progressive exertional dyspnea and cough of 3 months duration. One year before, when he started working in tunnel excavation, he had a normal chest radiograph. Chest imaging revealed bilateral nodules and masses of peribronchovascular distribution plus mediastinal lymphadenomegaly. Histologic lymph node analysis revealed non-caseating confluent granulomas. Sarcoidosis was diagnosed. The patient was treated with corticosteroids and advised to change jobs. Complete remission of the disease was achieved and persisted for at least one year without steroid treatment.

DISCUSSION

Sarcoidosis is believed to have environmental triggers. The timing of the onset of sarcoidosis in this patient following intensive exposure to tunnel dust suggests an environmental contribution. The recognition that sarcoidosis may have occupational triggers have medical, employment, and legal implications.

"Sarcoid like" granulomatous pulmonary disease in World Trade Center disaster responders

BACKGROUND

More than 20,000 responders have been examined through the World Trade Center (WTC) Medical Monitoring and Treatment Program since September 11, 2001. Studies on WTC firefighters have shown elevated rates of sarcoidosis. The main objective of this study was to report the incidence of "sarcoid like" granulomatous pulmonary disease in other WTC responders.

METHODS

Cases of sarcoid like granulomatous pulmonary disease were identified by: patient self-report, physician report and ICD-9 codes. Each case was evaluated by three pulmonologists using the ACCESS criteria and only "definite" cases are reported.

RESULTS

Thirty-eight patients were classified as "definite" cases. Six-year incidence was 192/100,000. The peak annual incidence of 54 per 100,000 person-years occurred between 9/11/2003 and 9/11/2004. Incidence in black responders was nearly double that of white responders. Low FVC was the most common spirometric abnormality.

CONCLUSIONS

Sarcoid like granulomatous pulmonary disease is present among the WTC responders. While the incidence is lower than that reported among firefighters, it is higher than expected.

Case report: analytical electron microscopy of lung granulomas associated with exposure to coating materials carried by glass wool fibers

CONTEXT

Man-made vitreous fibers (MMVFs) are noncrystalline inorganic fibrous material used for thermal and acoustical insulation (e.g., rock wool, glass wool, glass microfibers, and refractory ceramic fibers). Neither epidemiologic studies of human exposure nor animal studies have shown a noticeable hazardous effect of glass wools on health. However, MMVFs have been anecdotally associated with granulomatous lung disease in several case reports.

CASE PRESENTATION

Here, we describe the case of a patient with multiple bilateral nodular opacities who was exposed to glass wool fibers and coating materials for 7 years. Bronchoalveolar lavage fluid revealed an increased total cell count (predominantly macrophages) with numerous cytoplasmic particles. Lung biopsy showed peribronchiolar infiltration of lymphoid cells and many foreign-body-type granulomas. Alveolar macrophages had numerous round and elongated platelike particles inside the cytoplasm. X-ray microanalysis of these particles detected mainly oxygen/aluminum/silicon and oxygen/magnesium/silicon, compatible with kaolinite and talc, respectively. No elemental evidence for glass fibers was found in lung biopsy.

DISCUSSION

The contribution of analytical electron microscopy applied in the lung biopsy was imperative to confirm the diagnosis of pneumoconiosis associated with a complex occupational exposure that included both MMVFs and coating materials.

RELEVANCE TO CLINICAL OR PROFESSIONAL PRACTICE

This case study points out the possible participation of other components (coating materials), beyond MMVFs, in the etiology of pneumoconiosis.

The role of tumor necrosis factor alpha G-308A polymorphisms in the course of pulmonary sarcoidosis

This study was designed to evaluate the relationship between the presence of tumor necrosis factor (TNF) polymorphisms, human leukocyte antigen (HLA)-DRB1*03 linkage and the prognosis of sarcoidosis. In a retrospective case-control study, TNF-alpha G-308A, TNF-alpha G-238A, lymphotoxin-alpha (LTA) and HLA-DRB1*03 were genotyped in 625 sarcoidosis patients. These patients were classified into 298 patients with persistent disease and 327 patients with non-persistent disease using chest X-ray (CXR) appearances and lung function parameters after at least 2 years of follow-up. The TNF-alpha-308A variant allele was observed in 25.5% of patients with persistent disease compared with 44.0% of patients with non-persistent disease. The corresponding odds ratio (OR) was 0.43 with a 95% confidence interval (CI) of 0.30-0.61. A strong linkage was found between TNF-alpha G-308A and HLA-DRB1*03 (OR = 0.03, 95% CI: 0.02-0.05). For TNF-alpha G-238A and LTA NcoI A252G, there were no statistically significant differences in the distribution of genotypes between the groups with and without persistent disease. The data indicate that presence of a TNF-alpha-308A variant allele and HLA-DRB1*03 were associated with a favorable prognosis. Because of the strong linkage between TNF-alpha G-308A and HLA-DRB1*03, genotyping of one simple and less expensive TNF-alpha single nucleotide polymorphism can be used to predict the prognosis of pulmonary sarcoidosis in clinical practice.

A 26-Year-Old Welder with Severe Non-Reversible Obstructive Lung Disease

A 26-year-old white male, lifelong non-smoker presented with a history of increased shortness of breath, for approximately 1 year. He had a history of welding aluminum parts. He had evidence of partially reversible reactive airways disease with a non obstructive component as well. VATS biopsy revealed evidence of airway and parenchymal inflammation consistent with aluminum pneumoconiosis. Approximately 5-10% of COPD is attributable to non-smoking causes including occupational exposures. There are studies to suggest that the persistence of aluminum particulate may cause ongoing inflammation despite removal from exposure. It is possible that the persistence of particulate matter from tobacco smoke remaining in the lung may contribute to the persistent inflammatory response found in former smokers. Further study is required to examine the importance of this potential inflammatory mechanism both in occupationally exposed and in cigarette smokers. Reduction of certain particulate components of cigarette smoke may have implications for prevention of disease or at least disease progression in some COPD patients.

Upper and lower respiratory diseases after occupational and environmental disasters

Respiratory consequences from occupational and environmental disasters are the result of inhalation exposures to chemicals, particulate matter (dusts and fibers) and/or the incomplete products of combustion that are often liberated during disasters such as fires, building collapses, explosions and volcanoes. Unfortunately, experience has shown that environmental controls and effective respiratory protection are often unavailable during the first days to week after a large-scale disaster. The English literature was reviewed using the key words-disaster and any of the following: respiratory disease, pulmonary, asthma, bronchitis, sinusitis, pulmonary fibrosis, or sarcoidosis. Respiratory health consequences after aerosolized exposures to high-concentrations of particulates and chemicals can be grouped into 4 major categories: 1) upper respiratory disease (chronic rhinosinusitis and reactive upper airways dysfunction syndrome), 2) lower respiratory diseases (reactive [lower] airways dysfunction syndrome, irritant-induced asthma, and chronic obstructive airways diseases), 3) parenchymal or interstitial lung diseases (sarcoidosis, pulmonary fibrosis, and bronchiolitis obliterans, and 4) cancers of the lung and pleura. This review describes several respiratory consequences of occupational and environmental disasters and uses the World Trade Center disaster to illustrate in detail the consequences of chronic upper and lower respiratory inflammation.

World Trade Center "sarcoid-like" granulomatous pulmonary disease in New York City Fire Department rescue workers

BACKGROUND

Previous reports suggest that sarcoidosis occurs with abnormally high frequency in firefighters. We sought to determine whether exposure to World Trade Center (WTC) "dust" during the collapse and rescue/recovery effort increased the incidence of sarcoidosis or "sarcoid-like" granulomatous pulmonary disease (SLGPD).

METHODS

During the 5 years after the WTC disaster, enrollees in the Fire Department of New York (FDNY) WTC monitoring and treatment programs who had chest radiograph findings suggestive of sarcoidosis underwent evaluation, including the following: chest CT imaging, pulmonary function, provocative challenge, and biopsy. Annual incidence rates were compared to the 15 years before the WTC disaster.

RESULTS

After WTC dust exposure, pathologic evidence consistent with new-onset sarcoidosis was found in 26 patients: all 26 patients had intrathoracic adenopathy, and 6 patients (23%) had extrathoracic disease. Thirteen patients were identified during the first year after WTC dust exposure (incidence rate, 86/100,000), and 13 patients were identified during the next 4 years (average annual incidence rate, 22/100,000; as compared to 15/100,000 during the 15 years before the WTC disaster). Eighteen of 26 patients (69%) had findings consistent with asthma. Eight of 21 patients (38%) agreeing to challenge testing had airway hyperreactivity (AHR), findings not seen in FDNY sarcoidosis patients before the WTC disaster.

CONCLUSION

After the WTC disaster, the incidence of sarcoidosis or SLGPD was increased among FDNY rescue workers. This new information about the early onset of WTC-SLGPD and its association with asthma/AHR has important public health consequences for disease prevention, early detection, and treatment following environmental/occupational exposures.

[Granulomatous diseases of occupational etiology]

A variety of diseases are encompassed in the didactic denomination of "granulomatous diseases of probable occupational etiology". As well as presenting similar clinical aspects, such diseases are characterized by certain common traits: formation of granulomas; systemic and respiratory manifestations; environmental or occupational exposure to organic or inorganic agents; and T lymphocyte involvement in the pathogenesis. Included in this category are hypersensitivity pneumonitis, mycobacteriosis (all forms) and sarcoidosis, as well as beryllium disease and other lung diseases caused by exposure to heavy metals. In order to highlight the risk of developing one of these diseases as a result of environmental or occupational exposure to etiologic agents, we address aspects related to epidemiology, pathogenesis and evaluation of exposure of these diseases, as well as those related to diagnostic criteria, prevention and control. We have given special emphasis to groups of individuals considered to be at high risk for developing these diseases, as well as to the need for health care professionals to remain aware of the potential occupational etiology of such diseases, a decisive factor in devising effective measures of prevention and epidemiological surveillance.

Bérylliose pulmonaire chronique (2e partie)

INTRODUCTION

Chronic beryllium disease (CBD) is an occupational lung disease caused by the inhalation of beryllium dust, fumes or metallic salts.

CURRENT DATA

Beryllium affects the lungs via particles deposited in the pulmonary alveoli. These are ingested by alveolar macrophages which act as antigen presenting cells to CD4+ T lymphocytes. T lymphocytes proliferate in response to beryllium antigens and combined with macrophages produce numerous epithelioid granulomas with the release of inflammatory cytokines (IFNgamma, IL-2, TNFalpha and IL6) and growth factors. Beryllium induces macrophage apoptosis which reduces its clearance from the lung which in turn contributes to the host's continual re-exposure and thus a chronic granulomatous disorder. Pulmonary granulomatous inflammation is the primary manifestation of CBD, but the disease occasionally involves other organs such as the liver, spleen, lymph nodes and bone marrow. The clinical, radiological, and histopathological features of CBD can be difficult to distinguish from sarcoidosis. The Beryllium lymphocyte proliferation test (BeLPT) demonstrates a beryllium specific immune response, confirms the diagnosis of CBD, and excludes sarcoidosis.

CONCLUSIONS AND PERSPECTIVES

CBD provides a human model of pulmonary granulomatous disease produced by an occupational exposure, occurring more frequently in those with a genetic pre-disposition. It can be differentiated from sarcoidosis by specific immunological testing.

Trends and occupational associations in incidence of hospitalized pulmonary sarcoidosis and other lung diseases in Navy personnel: a 27-year historical prospective study, 1975-2001

STUDY OBJECTIVES

This study examines long-term trends in incidence rates of hospitalized pulmonary sarcoidosis in a large cohort of Navy personnel, and evaluates the possible relationship of sarcoidosis with occupation.

DESIGN

Incidence rates of first hospitalizations were determined for black and white male Navy enlisted personnel on active duty from 1975 to 2001.

SETTING

Navy service includes a potential for exposure to a variety of substances, including nonskid coatings used on ship decks that may be aerosolized during removal. Particulate matter containing aluminum, titanium, and silicates has been identified in nonskid samples. Specific occupational groups may have had greater exposure potential than others.

PATIENTS OR PARTICIPANTS

Hospitalized cases included sarcoidosis (n = 674), asthma (n = 3,536), emphysema and chronic bronchitis (n = 1,103), respiratory conditions due to fumes and vapors (n = 61), and pneumoconiosis (n = 51) observed in 9,953,607 person-years of active-duty service.

INTERVENTIONS

None. However, improvements were made in personal protective gear and other countermeasures to prevent or limit respiratory exposures during service.

MEASUREMENTS AND RESULTS

Annual overall hospitalized sarcoidosis incidence rates per 100,000 were 24.9 for black men and 3.5 for white men (black/white ratio of 7.1, p < 0.0001). Annual incidence rates in blacks declined markedly, particularly since 1989, but the black/white ratio remained high through 1999. Occupational associations were present in blacks and whites. Black ship's servicemen (23 cases) and aviation structural mechanics specializing in structures (12 cases) had more than twice the expected incidence rate compared to all blacks, and white mess management specialists (15 cases) had twice the overall white incidence rate.

CONCLUSIONS

There was a steep decline in incidence of hospitalized sarcoidosis in blacks in the Navy. Occupational associations suggest the possibility that a dust or moisture-related lung disease may have been erroneously classified as sarcoidosis, or, alternatively, that sarcoidosis had a previously unrecognized occupational component.

A case control etiologic study of sarcoidosis: environmental and occupational risk factors

Past research suggests that environmental factors may be associated with sarcoidosis risk. We conducted a case control study to test a priori hypotheses that environmental and occupational exposures are associated with sarcoidosis. Ten centers recruited 706 newly diagnosed patients with sarcoidosis and an equal number of age-, race-, and sex-matched control subjects. Interviewers administered questionnaires containing questions regarding occupational and nonoccupational exposures that we assessed in univariable and multivariable analyses. We observed positive associations between sarcoidosis and specific occupations (e.g., agricultural employment, odds ratio [OR] 1.46, confidence interval [CI] 1.13-1.89), exposures (e.g., insecticides at work, OR 1.52, CI 1.14-2.04, and work environments with mold/mildew exposures [environments with possible exposures to microbial bioaerosols], OR 1.61, CI 1.13-2.31). A history of ever smoking cigarettes was less frequent among cases than control subjects (OR 0.62, CI 0.50-0.77). In multivariable modeling, we observed elevated ORs for work in areas with musty odors (OR 1.62, CI 1.24-2.11) and with occupational exposure to insecticides (OR 1.61, CI 1.13-2.28), and a decreased OR related to ever smoking cigarettes (OR 0.65, CI 0.51-0.82). The study did not identify a single, predominant cause of sarcoidosis. We identified several exposures associated with sarcoidosis risk, including insecticides, agricultural employment, and microbial bioaerosols.

Sarcoidosis: benefits of a multidisciplinary approach

It is well established that sarcoidosis is a multisystem disorder of unknown cause(s). Practically no organ is immune to sarcoidosis. It subsides in most cases, but it may worsen and become chronic in others. Pulmonary problems may persist, but also devastating extrapulmonary complications may become apparent. Appropriate management of sarcoidosis is mandatory as it predominantly affects fairly young adults. This requires the attention of pulmonologists as well as specialists from other medical disciplines. Accordingly, when treating sarcoidosis patients, a multidisciplinary approach is recommended that focuses attention on somatic as well as psychosocial aspects of this erratic disorder. Specialists from all participating medical disciplines-including respiratory diseases-may benefit from a multidisciplinary approach and be stimulated to enhance their professional interest and knowledge of sarcoidosis. The benefit of such an approach should be explored in the near future.

Accumulation of ultrasmall superparamagnetic particles of iron oxide in human atherosclerotic plaques can be detected by in vivo magnetic resonance imaging

BACKGROUND

One of the features of high-risk atherosclerotic plaques is a preponderance of macrophages. Experimental studies with hyperlipidemic rabbits have shown that ultrasmall superparamagnetic particles of iron oxide (USPIOs) accumulate in plaques with a high macrophage content and that this induces magnetic resonance (MR) signal changes. The purpose of our study was to investigate whether USPIO-enhanced MRI can also be used for in vivo detection of macrophages in human plaques.

METHODS AND RESULTS

MRI was performed on 11 symptomatic patients scheduled for carotid endarterectomy before and 24 (n=11) and 72 (n=5) hours after administration of USPIOs (Sinerem) at a dose of 2.6 mg Fe/kg. Histological and electron microscopical analyses of the plaques showed USPIOs primarily in macrophages within the plaques in 10 of 11 patients. Histological analysis showed USPIOs in 27 of 36 (75%) of the ruptured and rupture-prone lesions and 1 of 14 (7%) of the stable lesions. Of the patients with USPIO uptake, signal changes in the post-USPIO MRI were observed by 2 observers in the vessel wall in 67 of 123 (54%) and 19 of 55 (35%) quadrants of the T2*-weighted MR images acquired after 24 and 72 hours, respectively. For those quadrants with changes, there was a significant signal decrease of 24% (95% CI, 33% to 15%) in regions of interest in the images acquired after 24 hours, whereas no significant signal change was found after 72 hours.

CONCLUSIONS

Accumulation of USPIOs in macrophages in predominantly ruptured and rupture-prone human atherosclerotic lesions caused signal decreases in the in vivo MR images.

Occupational risk factors for sarcoidosis in African-American siblings

OBJECTIVES

To determine whether certain occupations and occupationally related exposures were associated with a history of sarcoidosis in African-American siblings.

METHODS

We collected occupational data from 921 African Americans in 273 sibships that had been identified through a sarcoidosis case. Among the 648 siblings of sarcoidosis index cases enrolled, 30 (4.6%) also had a history of sarcoidosis. A detailed job history was obtained for any job held for > or = 6 months throughout the subject's life.

RESULTS

Having a usual occupation in education (odds ratio [OR], 2.18; 95% confidence interval [CI], 1.07 to 4.44), in metal machining (OR, 7.47; 95% CI, 1.19 to 47.06), and ever working in metalworking, not elsewhere classified (OR, 2.05; 95% CI, 1.14 to 3.70) were associated with increased sarcoidosis risk. Occupations ever held in the transportation services industry (OR, 12.71; 95% CI, 1.32 to 122.56) and usual occupations in the retail trade industry (OR, 0.49; 95% CI, 0.27 to 0.88) also were associated with sarcoidosis risk. Specific occupational exposures that were associated with sarcoidosis included titanium (OR, 3.15; 95% CI, 1.02 to 9.68) and vegetable dust (OR, 1.82; 95% CI, 1.01 to 3.27), and indoor exposure to high humidity (OR, 1.51; 95% CI, 1.13 to 2.02), water damage (OR, 1.50; 95% CI, 1.11 to 2.03), or musty odors (OR, 1.78; 95% CI, 1.32 to 2.40) for > 1 year.

CONCLUSION

Individuals who work in occupations with potential metal exposures or in workplaces with high humidity may be at an increased risk for sarcoidosis, but the complexity of occupationally related exposures makes it difficult to identify specific agents by using job titles as a surrogate for exposure. A more detailed exposure assessment of such jobs, along with the incorporation of genetic risk factors, should help to uncover the complex etiology of sarcoidosis.

What causes sarcoidosis?

Limited but encouraging progress has been made over the last several years in our understanding of the etiology of sarcoidosis as a result of recent investments in epidemiologic, immunologic, and molecular biologic studies. A recent US multicenter study of sarcoidosis found few environmental or occupational exposures associated with a two-fold or higher risk of development of sarcoidosis, suggesting noninfectious exposures play a small, if any, role in causing systemic sarcoidosis. In contrast, recent studies have linked infectious agents including mycobacterial and propionibacterial organisms with sarcoidosis. The association of sarcoidosis with the use of Th1-promoting biologic response modifiers is consistent with a central role for enhanced Th1 immune responses in the pathogenesis of sarcoidosis. Given evidence for a genetic predisposition to sarcoidosis, these findings suggest that the etiology of systemic sarcoidosis is linked to genetically determined enhanced Th1 immune responses to a limited number of microbial pathogens.

Role of bronchoalveolar lavage in interstitial lung disease

Bronchoalveolar lavage remains an important research tool in understanding ILD. It is still an important part of the clinical management of patients with ILD. It is most useful in detecting unusual forms of ILD. It helps the clinician narrow down the possible causes of the interstitial pattern. It also can confirm a clinical impression of certain conditions. Although rarely diagnostic, it is often supportive. In conjunction with high-resolution CT scan, most patients with ILD can be diagnosed using relatively noninvasive methods.