The incidence, prevalence, and severity of sarcoidosis in New York City firefighters

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.

Sarcoidosis and its relation to other immune-mediated diseases: Epidemiological insights

Several epidemiological studies show a co-occurrence of sarcoidosis with other immune-mediated diseases (IMD). There are many similarities between sarcoidosis and IMDs in their geographical distribution and risk factors. Understanding these similarities and identifying the differences can help us to better understand sarcoidosis and put it into context with other IMDs. In this review, we present the current knowledge about the overlap between sarcoidosis and other IMDs derived from epidemiological studies. Epidemiologic methods utilize study design and statistical analysis to describe the patterns in data and, ideally, identify causal relationships between an exposure and a health outcome. We discuss how study design and analysis may affect the interpretation of epidemiological studies on this topic and highlight some theories that attempt to explain the relation between sarcoidosis and other IMDs.

Airborne occupational exposures associated with pulmonary sarcoidosis: a systematic review and meta-analysis

The aetiology and pathophysiology of sarcoidosis is ill defined-current hypotheses centre on complex genetic-immune-environmental interactions in an individual, triggering a granulomatous process. The aim of this systematic review is to define and describe which airborne occupational exposures (aOE) are associated with and precede a diagnosis of pulmonary sarcoidosis. The methodology adopted for the purpose was systematic review and meta-analyses of ORs for specified aOE associated with pulmonary sarcoidosis (DerSimonian Laird random effects model (pooled log estimate of OR)). Standard search terms and dual review at each stage occurred. A compendium of aOE associated with pulmonary sarcoidosis was assembled, including mineralogical studies of sarcoidosis granulomas. N=81 aOE were associated with pulmonary sarcoidosis across all study designs. Occupational silica, pesticide and mould or mildew exposures were associated with increased odds of pulmonary sarcoidosis. Occupational nickel and aluminium exposure were associated with a non-statistically significant increase in the odds of pulmonary sarcoidosis. Silica exposure associated with pulmonary sarcoidosis was reported most frequently in the compendium (n=33 studies) and was the most common mineral identified in granulomas. It was concluded that aOE to silica, pesticides and mould or mildew are associated with increased odds of pulmonary sarcoidosis. Equipoise remains concerning the association and relationship of metal dusts with pulmonary sarcoidosis.

Towards a Race-Neutral System of Pulmonary Function Test Results Interpretation

It has been observed widely that, on average, Black individuals in the United States have lower FVC than White individuals, which is thought to reflect a combination of genetic, environmental, and socioeconomic factors that are difficult to disentangle. Debate therefore persists even after the American Thoracic Society's 2023 guidelines recommending race-neutral pulmonary function test (PFT) result interpretation strategies. Advocates of race-based PFT results interpretation argue that it allows for more precise measurement and will minimize disease misclassification. In contrast, recent studies have shown that low lung function in Black patients has clinical consequences. Furthermore, the use of race-based algorithms in medicine in general is increasingly being questioned for its risk of perpetuating structural health care disparities. Given these concerns, we believe it is time to adopt a race-neutral approach, but note that more research is urgently needed to understand how race-neutral approaches impact PFT results interpretation, clinical decision-making, and patient outcomes. In this brief case-based discussion, we offer a few examples of how a race-neutral PFT results interpretation strategy will impact individuals from racial and ethnic minority groups at different scenarios and stages of life.

Sarcoidosis: Epidemiology and clinical insights

Sarcoidosis is characterized by noncaseating granulomas which form in almost any part of the body, primarily in the lungs and/or thoracic lymph nodes. Environmental exposures in genetically susceptible individuals are believed to cause sarcoidosis. There is variation in incidence and prevalence by region and race. Males and females are almost equally affected, although disease peaks at a later age in females than in males. The heterogeneity of presentation and disease course can make diagnosis and treatment challenging. Diagnosis is suggestive in a patient if one or more of the following is present: radiologic signs of sarcoidosis, evidence of systemic involvement, histologically confirmed noncaseating granulomas, sarcoidosis signs in bronchoalveolar lavage fluid (BALF), and low probability or exclusion of other causes of granulomatous inflammation. No sensitive or specific biomarkers for diagnosis and prognosis exist, but there are several that can be used to support clinical decisions, such as serum angiotensin-converting enzyme levels, human leukocyte antigen types, and CD4 Vα2.3+ T cells in BALF. Corticosteroids remain the mainstay of treatment for symptomatic patients with severely affected or declining organ function. Sarcoidosis is associated with a range of adverse long-term outcomes and complications, and with great variation in prognosis between populations. New data and technologies have moved sarcoidosis research forward, increasing our understanding of the disease. However, there is still much left to be discovered. The pervading challenge is how to account for patient variability. Future studies should focus on how to optimize current tools and develop new approaches so that treatment and follow-up can be targeted to individuals with more precision.

Non-cancer health risks in firefighters: a systematic review

osFirefighters are occupationally exposed to hazardous factors that may increase their risk of disease. However, non-cancer disease risk in firefighters has not been systematically examined. This systematic review aimed to identify non-cancer disease risk in firefighters and determine whether the risk differs according to job characteristics. We searched the Cochrane Library, Embase, PubMed, and KoreaMed databases using relevant keywords from their inception to April 30, 2021. The Risk of Bias Assessment Tool for Non-randomized Studies version 2.0 was used to assess the quality of evidence. Due to study heterogeneity, a narrative synthesis was presented. The systematic literature search yielded 2,491 studies, of which 66 met the selection and quality criteria. We confirmed that the healthy worker effect is strong in firefighters as compared to the general population. We also identified a significant increase in the incidence of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and post-traumatic stress disorder (PTSD) in firefighters compared to other occupational groups. Contradictory results for the risk of PTSD and anxiety disorders related to rank were reported. Sufficient evidence for increased risk of lumbar disc herniation, lower back pain, angina pectoris, acute myocardial infarction, and PTSD was available. The risk of non-cancer diseases varied depending on job type, years of service, and rank. However, caution should be exercised when interpreting the results because the classification criteria for firefighters' jobs and ranks differ by country.

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.

Interstitial Lung Disease in Firefighters: An Emerging Occupational Hazard

Introduction

Occupational risk factors for interstitial lung disease (ILD) are a remediable aspect of this progressive pulmonary disorder. The association between firefighting and ILD is unknown. Our objective was to assess the characteristics of firefighters with ILD from a large single-center ILD registry.

Methods

The University of Chicago ILD database was reviewed for patients with a history of firefighting. Clinical information was abstracted from the medical record. The prevalence rate ratio of firefighters in the database compared to the baseline prevalence of firefighting in the Chicago metropolitan area was calculated via the Poisson distribution.

Results

Nineteen firefighters were identified; all were men. A variety of ILD subtypes were seen across the cohort, including four patients with a diagnosis of connective tissue disease. Patients had mild forced vital capacity (FVC) and moderate diffusing capacity for carbon monoxide (DLCO) decrements on presentation; three patients died and two received lung transplantation over an average follow-up time of 76 months. Firefighters were seen at a greater proportion in the ILD registry than in the general population with a prevalence rate ratio of 3.98.

Conclusions

Firefighting was overrepresented in our cohort compared to the general population, suggesting that there may be a causative association between firefighting and the presence of ILD. The wide variety of ILD subtypes observed suggest that all ILD patients should be asked about their occupational history. Further investigation to identify occupational exposures and determine the benefit of remediation is needed.

Occupational exposures and sarcoidosis: current understanding and knowledge gaps

PURPOSE OF REVIEW

Sarcoidosis is an idiopathic granulomatous disease that primarily affects the lungs. Several lines of evidence suggest that occupational exposures are associated with disease risk. This review critically evaluates studies using the Bradford Hill criteria for causation to determine if a causal relationship can be established between occupational exposure and sarcoidosis.

RECENT FINDINGS

Large epidemiological studies have proposed multiple occupational exposures associated with sarcoidosis but lack consistency of results. Many convincing studies demonstrate an association between World Trade Center (WTC) dust and sarcoidosis, which illustrates a causal relationship based on the fulfillment of the Bradford Hill criteria. Studies describing an association between silica/metals and sarcoidosis are intriguing but fulfill a limited number of the Bradford Hill criteria and warrant further investigation before a causal relationship can be determined. Finally, we also discuss preliminary studies associating sarcoidosis phenotypes with specific occupational exposures.

SUMMARY

Using the Bradford Hill criteria for causation, we demonstrate that WTC dust has a causative relationship with sarcoidosis, which reinforces the theory that sarcoidosis is an exposure-related disease. More research is needed to determine other specific occupational exposures causing disease.

Sarcoidosis in Iceland: a nationwide study of epidemiology, clinical picture and environmental exposure

Background

This nationwide study aimed to elucidate the incidence and clinical characteristics of tissue-verified sarcoidosis in Iceland. A secondary aim was to analyse sex differences and identify possible environmental factors contributing to the pathological process.

Materials and methods

This is a descriptive study covering 36 years (January 1, 1981 through December 31, 2016). Histopathological reports and electronic hospital discharge registries were reviewed in context for granulomas and/or sarcoidosis. National data were used for comparison regarding smoking habits and occupation, adjusted for age, sex and year of diagnosis. The data were stored in FileMaker and calculations were made by extracting data from this database to the statistical software package R.

Results

A total of 418 patients (54% females) were diagnosed with tissue-verified sarcoidosis. The incidence rate was 4.15/100 000/year, similar among females and males. The mean age at diagnosis was higher among females (53.0±14.2 years) than males (48.2±13.8 years). Fatigue was the most frequent single symptom (49.7%), but when all respiratory symptoms were grouped, they were the most frequent symptoms (60%). No significant difference was found between smoking status and sarcoidosis. Possible hazardous exposure in the workplace was reported by 19.4% of the cases.

Conclusion

The incidence of sarcoidosis in Iceland was higher than in an Asian population where the same inclusion criteria were applied. The clinical picture diverges partly from that in the Asian population but resembles that among other Caucasians. Fatigue and respiratory symptoms were predominant. The biphasic pattern of age at disease debut seen elsewhere among females was not evident in Iceland.

This paper describes a nationwide study on the incidence of tissue-verified sarcoidosis in Iceland, focusing on clinical symptoms, smoking and occupation. The incidence is low, and main symptoms are fatigue and symptoms of the respiratory tract.https://bit.ly/3ur6jk8

Canadian Career Firefighters' Mental Health Impacts and Priorities

Firefighters' perceptions of mental health can inform management. This qualitative study explored Canadian career firefighters' experiences, needs, and research priorities with respect to mental health. Thirty-nine career firefighters (33 men, 6 women) of different ranks and geographic locales were interviewed using a semi-structured interview guide. The interviews were recorded, transcribed, and qualitatively analyzed using thematic analysis within an interpretive description approach. Firefighters reported that critical incidents and chronic job stressors contributed to mental health symptoms that led to burnout, compassion fatigue, and mental and physical injury. They were concerned with family impacts, like lack of full openness, reduced financial stability, and risk of divorce; and work impacts, like interpersonal conflict, lack of support to fellow firefighters, task avoidance, and absenteeism. A broad array of barriers and facilitators were found in firefighter work, culture, programs, social supports, health care, and societal factors. Variability in access to help, the changing fire service, and the complexity of knowing what to do to achieve mental health were evident across themes. Firefighters identified the need for research in four areas: awareness and monitoring, understanding etiology of mental health, better prevention and treatment, and access to care. Across domains of inquiry, context, "two sides to the coin", and uncertainty were overarching themes.

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.

Sarcoidosis: An Occupational Disease?

Sarcoidosis is an important member of the family of granulomatous lung diseases. Since its recognition in the late 19th century, sarcoidosis has been thought of as a disease of unknown cause. Over the past 20 years, this paradigm has been shifting, more rapidly in the past 10 years. Epidemiologic studies, bolstered by case reports, have provided evidence of causal associations between occupational exposure to specific agents and sarcoidosis. Pathogenesis has been more clearly defined, including the role of gene-exposure interactions. The use of in vitro lymphocyte proliferation testing to detect sensitization to inorganic antigens is being examined in patients with sarcoidosis. These antigens include silica and certain metals. Results of studies to date show differences in immunoreactivity of occupationally exposed sarcoidosis cases compared with control cases, suggesting that lymphocyte proliferation testing may prove useful in diagnosing work-related disease. This review discusses recently published findings regarding associations between occupational exposure to silica and silicates, World Trade Center dust, and metals and risk for sarcoidosis, as well as advances in the development of diagnostic tools. Not all cases of sarcoidosis have an identified cause, but some do. Where the cause is occupational, its recognition is critical to enable effective treatment through removal of the affected worker from exposure and to inform intervention aimed at primary prevention.

Studies in a Murine Granuloma Model of Instilled Carbon Nanotubes: Relevance to Sarcoidosis

Poorly soluble environmental antigens, including carbon pollutants, are thought to play a role in the incidence of human sarcoidosis, a chronic inflammatory granulomatous disease of unknown causation. Currently, engineered carbon products such as multiwall carbon nanotubes (MWCNT) are manufactured commercially and have been shown to elicit acute and chronic inflammatory responses in experimental animals, including the production of granulomas or fibrosis. Several years ago, we hypothesized that constructing an experimental model of chronic granulomatosis resembling that associated with sarcoidosis might be achieved by oropharyngeal instillation of MWCNT into mice. This review summarizes the results of our efforts to define mechanisms of granuloma formation and identify potential therapeutic targets for sarcoidosis. Evidence is presented linking findings from the murine MWCNT granuloma model to sarcoidosis pathophysiology. As our goal was to determine what pulmonary inflammatory pathways might be involved, we utilized mice of knock-out (KO) backgrounds which corresponded to deficiencies noted in sarcoidosis patients. A primary example of this approach was to study mice with a myeloid-specific knock-out of the lipid-regulated transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) which is strikingly depressed in sarcoidosis. Among the major findings associated with PPARγ KO mice compared to wild-type were: (1) exacerbation of granulomatous and fibrotic histopathology in response to MWCNT; (2) elevation of inflammatory mediators; and (3) pulmonary retention of a potentially antigenic ESAT-6 peptide co-instilled with MWCNT. In line with these data, we also observed that activation of PPARγ in wild-type mice by the PPARγ-specific ligand, rosiglitazone, significantly reduced both pulmonary granuloma and inflammatory mediator production. Similarly, recognition of a deficiency of ATP-binding cassette (ABC) lipid transporter ABCG1 in sarcoidosis led us to study MWCNT instillation in myeloid-specific ABCG1 KO mice. As anticipated, ABCG1 deficiency was associated with larger granulomas and increased levels of inflammatory mediators. Finally, a transcriptional survey of alveolar macrophages from MWCNT-instilled wild-type mice and human sarcoidosis patients revealed several common themes. One of the most prominent mediators identified in both human and mouse transcriptomic analyses was MMP12. Studies with MMP12 KO mice revealed similar acute reactions to those in wild-type but at chronic time points where wild-type maintained granulomatous disease, resolution occurred with MMP12 KO mice suggesting MMP12 is necessary for granuloma progression. In conclusion, these studies suggest that the MWCNT granuloma model has relevance to human sarcoidosis study, particularly with respect to immune-specific pathways.

The role of occupational factors in the development and course of respiratory sarcoidosis

Aim. The aim of the study was to study the frequency of occurrence of exposure to harmful occupational factors in patients with sarcoidosis of the respiratory organs, depending on the course of the disease. Materials and methods. An open prospective study included 121 patients with sarcoidosis of the respiratory system from the age of 21 to 66 years, from 20072019. The diagnosis was histologically confirmed in all patients. Patients underwent a set of laboratory and instrumental examinations, studied profane history. The presence of a history of contact with harmful and dangerous production factors was clarified. To determine the effect of a harmful production factor on the course of sarcoidosis, patients were divided into 2 clinical groups: the first group consisted of 85 (70.2%) patients with a favorable course of the disease, the second group included 36 (29.8%) patients with an unfavorable course sarcoidosis (standardization coefficient between groups 2.4:1). Results and discussion. Among the examined patients of working age prevailed (87%). Patient groups were comparable by age, but statistically differed by gender (chi2=9.75, p=0.0018). Frequency analysis of the occurrence of harmful occupational factors in sarcoidosis of the respiratory organs showed that the most frequently encountered factors in all the studied groups were contact with chemical hazards. Conclusion. The presence of contact with harmful production factors increases the risk of an unfavorable course of sarcoidosis by more than 2 times.

Biologic and advanced immunomodulating therapeutic options for sarcoidosis: a clinical update

Introduction: Sarcoidosis is a multi-organ disease with a wide range of clinical manifestations and outcomes. A quarter of sarcoidosis patients require long-term treatment for chronic disease. In this group, corticosteroids and cytotoxic agents be insufficient to control diseaseAreas covered: Several biologic agents have been studied for treatment of chronic pulmonary and extra-pulmonary disease. A review of the available literature was performed searching PubMed and an expert opinion regarding specific therapy was developed.Expert opinion: These agents have the potential of treating patients who have progressive disease. Many of these agents have different mechanisms of action, response rates, and toxicity profiles.

A rare case of follicular sarcoidosis

The article is devoted to a rare variant of skin sarcoidosis the so-called follicular sarcoidosis. According to the literature, the follicular form of sarcoidosis is extremely rare, several isolated cases are described in foreign literature, there are no publications in the russian literature. A 30-year-old female patient came to the clinic of the Military Medical Academy with a skin rash of the upper extremities, trunk and neck that lasted for one year. Anamnesis: repeated use of topical corticosteroids for the treatment with a temporary positive effect. The skin process was represented by common follicular papules; a histological examination of one of the elements revealed granulomas of the sarcoid type, which were located perifolliculary, mainly around the infundibular sections of the hair follicles. The rash resolved after a course of external corticosteroid therapy. The clinical case described by us illustrates the need for histological examination to verify the diagnosis.

Potential use of biomarkers for the clinical evaluation of sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology and pathogenesis with a heterogeneous clinical presentation. In the appropriate clinical and radiological context and with the exclusion of other diagnoses, the disease is characterized by the pathological presence of non-caseating epithelioid cell granulomas. Sarcoidosis is postulated to be a multifactorial disease caused by chronic antigenic stimulation. The immunopathogenesis of sarcoidosis encompasses a complex interaction between the host, genetic factors and postulated environmental and infectious triggers, which result in granuloma development.The exact pathogenesis of the disease has yet to be elucidated, but some of the inflammatory pathways that play a key role in disease progression and outcomes are becoming apparent, and these may form the logical basis for selecting potential biomarkers.Biomarkers are biological molecules that are altered pathologically. To date, there exists no single reliable biomarker for the evaluation of sarcoidosis, either diagnostically or prognostically but new candidates are emerging. A diagnosis of sarcoidosis ideally requires a biopsy confirming non-caseating granulomas, but the likelihood of progression that requires intervention remains unpredictable. These challenging aspects could be potentially resolved by incorporating biomarkers into clinical practice for both diagnosis and monitoring disease activity.This review outlines the current knowledge on sarcoidosis with an emphasis on pulmonary sarcoidosis, and delineates the understanding surrounding the implication of biomarkers for the clinical evaluation of sarcoidosis.

The Clinical Features of Patients with Sarcoidosis and Malignant Diseases in Japan

Objective Recent studies suggest a significant association between sarcoidosis and malignancy, although the results have remained controversial. The aim of this study is to evaluate the clinical features of patients with sarcoidosis associated with malignant diseases in Japan. Patients We conducted a medical record review of all sarcoidosis patients in Tohoku University Hospital between January 1, 1981, and May 31, 2017. Methods The clinical records and pathology reports for each patient were screened, and the clinical characteristics of malignancies as well as sarcoidosis were reviewed. Results A total of 52 (18.8%) patients with malignancy were identified among 277 patients with sarcoidosis. Among those 52 patients, we identified 62 with malignant diseases. These patients were older and more likely to be women than the remaining 225 (81.2%) sarcoidosis patients without malignancy. The most prevalent malignant disease was breast cancer (14 cases, 22.6%), followed by stomach cancer (8 cases, 12.9%) and lung cancer (7 cases, 11.3%). Among the 14 patients with both sarcoidosis and breast cancer, 8 (57.1%) were diagnosed with breast cancer before sarcoidosis. All of these eight cases had undergone surgical resection of the cancer. Conclusion This study showed a higher incidence of patients with both sarcoidosis and malignancy in Japan than in some western countries. Breast cancer is the most prevalent malignant disease. The high frequency of sarcoidosis after surgical resection of breast cancer may suggest a causative association between malignancy and the development of sarcoidosis.

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.

Peroxisome Proliferator-activated Receptor-γ Deficiency Exacerbates Fibrotic Response to Mycobacteria Peptide in Murine Sarcoidosis Model

We established a murine model of multiwall carbon nanotube (MWCNT)-elicited chronic granulomatous disease that bears similarities to human sarcoidosis pathology, including alveolar macrophage deficiency of peroxisome proliferator-activated receptor γ (PPARγ). Because lymphocyte reactivity to mycobacterial antigens has been reported in sarcoidosis, we hypothesized that addition of mycobacterial ESAT-6 (early secreted antigenic target protein 6) to MWCNT might exacerbate pulmonary granulomatous pathology. MWCNTs with or without ESAT-6 peptide 14 were instilled by the oropharyngeal route into macrophage-specific PPARγ-knockout (KO) or wild-type mice. Control animals received PBS or ESAT-6. Lung tissues, BAL cells, and BAL fluid were evaluated 60 days after instillation. PPARγ-KO mice receiving MWCNT + ESAT-6 had increased granulomas and significantly elevated fibrosis (trichrome staining) compared with wild-type mice or PPARγ-KO mice that received only MWCNT. Immunostaining of lung tissues revealed elevated fibronectin and Siglec F expression on CD11c⁺ infiltrating alveolar macrophages in the presence of MWCNT + ESAT-6 compared with MWCNT alone. Analyses of BAL fluid proteins indicated increased levels of transforming growth factor (TGF)-β and the TGF-β pathway mediator IL-13 in PPARγ-KO mice that received MWCNT + ESAT-6 compared with wild-type or PPARγ-KO mice that received MWCNT. Similarly, mRNA levels of matrix metalloproteinase 9, another requisite factor for TGF-β production, was elevated in PPARγ-KO mice by MWCNT + ESAT-6. Analysis of ESAT-6 in lung tissues by mass spectrometry revealed ESAT-6 retention in lung tissues of PPARγ-KO but not wild-type mice. These data indicate that PPARγ deficiency promotes pulmonary ESAT-6 retention, exacerbates macrophage responses to MWCNT + ESAT-6, and intensifies pulmonary fibrosis. The present findings suggest that the model may facilitate understanding of the effects of environmental factors on sarcoidosis-associated pulmonary fibrosis.

Alveolar Macrophage ABCG1 Deficiency Promotes Pulmonary Granulomatous Inflammation

Pulmonary granuloma formation is a complex and poorly understood response to inhaled pathogens and particulate matter. To explore the mechanisms of pulmonary granuloma formation and maintenance, our laboratory has developed a multiwall carbon nanotube (MWCNT)-induced murine model of chronic granulomatous inflammation. We have demonstrated that the MWCNT model closely mimics pulmonary sarcoidosis pathophysiology, including the deficiency of alveolar macrophage ATP-binding cassette (ABC) lipid transporters ABCA1 and ABCG1. We hypothesized that deficiency of alveolar macrophage ABCA1 and ABCG1 would promote pulmonary granuloma formation and inflammation. To test this hypothesis, the effects of MWCNT instillation were evaluated in ABCA1, ABCG1, and ABCA1/ABCG1 myeloid-specific knockout (KO) mice. Histological examination revealed significantly larger pulmonary granulomas in ABCG1-KO and ABCA1/ABCG1 double-KO animals when compared with wild-type animals. Evaluation of BAL cells indicated increased expression of CCL2 and osteopontin, genes shown to be involved in the formation and maintenance of pulmonary granulomas. Single deficiency of alveolar macrophage ABCA1 did not affect MWCNT-induced granuloma formation or proinflammatory gene expression. These observations indicate that the deficiency of alveolar macrophage ABCG1 promotes pulmonary granulomatous inflammation and that this is augmented by additional deletion of ABCA1.

PPARγ Deficiency in Carbon Nanotube-elicited Granulomatous Inflammation Promotes a Th17 Response to a Microbial Antigen

BACKGROUND

The pathological consequences of interaction between environmental carbon pollutants and microbial antigens have not been fully explored. We developed a murine model of multi-wall carbon nanotube (MWCNT)-elicited granulomatous disease which bears a striking resemblance to sarcoidosis, a human granulomatous disease. Because of reports describing lymphocyte reactivity to mycobacterial antigens in sarcoidosis patients, we hypothesized that addition of mycobacterial antigen (ESAT-6) to MWCNT might elicit activation in T cells.

METHODS

Macrophage-specific peroxisome-proliferator-activated receptor gamma (PPARγ) knock out (KO) mice were studied along with wild-type mice because our previous report indicated PPARγ deficiency in sarcoidosis alveolar macrophages. MWCNT+ESAT-6 were instilled into mice. Controls received vehicle (surfactant-PBS) or ESAT-6 and were evaluated 60 days post-instillation. As noted in our recent publication, lung tissues from PPARγ KO mice instilled with MWCNT+ESAT-6 yielded more intensive pathophysiology, with elevated fibrosis.

RESULTS

Inspection of mediastinal lymph nodes (MLN) revealed no granulomas but deposition of MWCNT. MLN cell counts were higher in PPARγ KO than in wild-type instilled with MWCNT+ESAT-6. Moreover, the CD4:CD8 T cell ratio, a major clinical metric for human disease, was increased in PPARγ KO mice. Bronchoalveolar lavage (BAL) cells from PPARγ KO mice instilled with MWCNT+ESAT-6 displayed increased Th17 cell markers (RORγt, IL-17A, CCR6) which associate with elevated fibrosis.

CONCLUSION

These findings suggest that PPARγ deficiency in macrophages may promote ESAT-6-associated T cell activation in the lung, and that the MWCNT+ESAT-6 model may offer new insights into pathways of lymphocyte-mediated sarcoidosis histopathology.

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.

Sarcoidosis

Sarcoidosis is an inflammatory disorder of unknown cause that is characterized by granuloma formation in affected organs, most often in the lungs. Patients frequently suffer from cough, shortness of breath, chest pain and pronounced fatigue and are at risk of developing lung fibrosis or irreversible damage to other organs. The disease develops in genetically predisposed individuals with exposure to an as-yet unknown antigen. Genetic factors affect not only the risk of developing sarcoidosis but also the disease course, which is highly variable and difficult to predict. The typical T cell accumulation, local T cell immune response and granuloma formation in the lungs indicate that the inflammatory response in sarcoidosis is induced by specific antigens, possibly including self-antigens, which is consistent with an autoimmune involvement. Diagnosis can be challenging for clinicians because of the potential for almost any organ to be affected. As the aetiology of sarcoidosis is unknown, no specific treatment and no pathognomic markers exist. Thus, improved biomarkers to determine disease activity and to identify patients at risk of developing fibrosis are needed. Corticosteroids still constitute the first-line treatment, but new treatment strategies, including those targeting quality-of-life issues, are being evaluated and should yield appropriate, personalized and more effective treatments.

Genetic Variants Associated with FDNY WTC-Related Sarcoidosis

Sarcoidosis is a systemic granulomatous disease of unknown etiology. It may develop in response to an exposure or inflammatory trigger in the background of a genetically primed abnormal immune response. Thus, genetic studies are potentially important to our understanding of the pathogenesis of sarcoidosis. We developed a case-control study which explored the genetic variations between firefighters in the Fire Department of the City of New York (FDNY) with World Trade Center (WTC)-related sarcoidosis and those with WTC exposure, but without sarcoidosis. The loci of fifty-one candidate genes related to granuloma formation, inflammation, immune response, and/or sarcoidosis were sequenced at high density in enhancer/promoter, exonic, and 5’ untranslated regions. Seventeen allele variants of human leukocyte antigen (HLA) and non-HLA genes were found to be associated with sarcoidosis, and all were within chromosomes 1 and 6. Our results also suggest an association between extrathoracic involvement and allele variants of HLA and non-HLA genes found not only on chromosomes 1 and 6, but also on chromosomes 16 and 17. We found similarities between genetic variants with WTC-related sarcoidosis and those reported previously in sporadic sarcoidosis cases within the general population. In addition, we identified several allele variants never previously reported in association with sarcoidosis. If confirmed in larger studies with known environmental exposures, these novel findings may provide insight into the gene-environment interactions key to the development of sarcoidosis.

Bone marrow involvement in sarcoidosis: an elusive extrapulmonary manifestation

Sarcoidosis is a granulomatous disease with various extrapulmonary manifestations. We describe a 51-year-old African American woman with a history of cutaneous sarcoidosis admitted with bicytopenia. Suspicion for systemic sarcoidosis was established after contrast-enhanced computerized tomography of the chest, abdomen and pelvis showed a pulmonary nodule, diffuse lymphadenopathy and hepatosplenomegaly. Cytopenias in sarcoidosis, when present, may reflect bone marrow infiltration. Hence, biopsy was obtained and bone marrow sarcoidosis was diagnosed. This manifestation, in spite of ethnic and gender predilection, is rarely seen. As with other forms of sarcoidosis, treatment comprises of corticosteroids.

Abbreviations: ANCA: Antineutrophil cytoplasmic antibody; BM: Bone marrow; BMS: Bone marrow sarcoidosis; CT: Computerized tomography; HIV: Human immunodeficiency virus; HLA: Human leukocyte antigen; MRI: Magnetic resonance imaging

Epidemiology of sarcoidosis: current findings and future directions

Sarcoidosis is a granulomatous inflammatory disease with unknown etiology. Epidemiological studies have contributed greatly to our knowledge about sarcoidosis, providing critical information on the determinants and distribution of the disease. In this review, we summarize recently published findings from epidemiological studies on sarcoidosis. We review the epidemiological tools used, the incidence and prevalence of disease, mortality and cancer risk after sarcoidosis and nongenetic risk factors for sarcoidosis. Genetics studies have not been included as they deserve a separate review. Leveraging existing epidemiological data to conduct etiological studies aimed towards understanding and preventing disease is critical for future sarcoidosis research.

PPAR-gamma pathways attenuate pulmonary granuloma formation in a carbon nanotube induced murine model of sarcoidosis

Peroxisome proliferator activated receptor gamma (PPARγ), a ligand activated nuclear transcription factor, is constitutively expressed in alveolar macrophages of healthy individuals. PPARγ deficiencies have been noted in several lung diseases including the alveolar macrophages of pulmonary sarcoidosis patients. We have previously described a murine model of multiwall carbon nanotubes (MWCNT) induced pulmonary granulomatous inflammation which bears striking similarities to pulmonary sarcoidosis, including the deficiency of alveolar macrophage PPARγ. Further studies demonstrate alveolar macrophage PPARγ deficiency exacerbates MWCNT-induced pulmonary granulomas. Based on these observations we hypothesized that activation of PPARγ via administration of the PPARγ-specific ligand rosiglitazone would limit MWCNT-induced granuloma formation and promote PPARγ-dependent pathways. Results presented here show that rosiglitazone significantly limits the frequency and severity of MWCNT-induced pulmonary granulomas. Furthermore, rosiglitazone attenuates alveolar macrophage NF-κB activity and downregulates the expression of the pro-inflammatory mediators, CCL2 and osteopontin. PPARγ activation via rosiglitazone also prevents the MWCNT-induced deficiency of PPARγ-regulated ATP-binding cassette lipid transporter-G1 (ABCG1) expression. ABCG1 is crucial to pulmonary lipid homeostasis. ABCG1 deficiency results in lipid accumulation which promotes pro-inflammatory macrophage activation. Our results indicate that restoration of homeostatic ABCG1 levels by rosiglitazone correlates with both reduced pulmonary lipid accumulation, and decreased alveolar macrophage activation. These data confirm and further support our previous observations that PPARγ pathways are critical in regulating MWCNT-induced pulmonary granulomatous inflammation.

Clinical Course of Sarcoidosis in World Trade Center-Exposed Firefighters

BACKGROUND

Sarcoidosis is believed to represent a genetically primed, abnormal immune response to an antigen exposure or inflammatory trigger, with both genetic and environmental factors playing a role in disease onset and phenotypic expression. In a population of firefighters with post-World Trade Center (WTC) 9/11/2001 (9/11) sarcoidosis, we have a unique opportunity to describe the clinical course of incident sarcoidosis during the 15 years postexposure and, on average, 8 years following diagnosis.

METHODS

Among the WTC-exposed cohort, 74 firefighters with post-9/11 sarcoidosis were identified through medical records review. A total of 59 were enrolled in follow-up studies. For each participant, the World Association of Sarcoidosis and Other Granulomatous Diseases organ assessment tool was used to categorize the sarcoidosis involvement of each organ system at time of diagnosis and at follow-up.

RESULTS

The incidence of sarcoidosis post-9/11 was 25 per 100,000. Radiographic resolution of intrathoracic involvement occurred in 24 (45%) subjects. Lung function for nearly all subjects was within normal limits. Extrathoracic involvement increased, most prominently joints (15%) and cardiac (16%) involvement. There was no evidence of calcium dysmetabolism. Few subjects had ocular (5%) or skin (2%) involvement, and none had beryllium sensitization. Most (76%) subjects did not receive any treatment.

CONCLUSIONS

Extrathoracic disease was more prevalent in WTC-related sarcoidosis than reported for patients with sarcoidosis without WTC exposure or for other exposure-related granulomatous diseases (beryllium disease and hypersensitivity pneumonitis). Cardiac involvement would have been missed if evaluation stopped after ECG, 48-h recordings, and echocardiogram. Our results also support the need for advanced cardiac screening in asymptomatic patients with strenuous, stressful, public safety occupations, given the potential fatality of a missed diagnosis.

Granulomatous diseases: Kids are not just little people

Granulomatous diseases represent a heterogeneous group of conditions characterized by histiocytic inflammation that affect patients of any age. These diseases differ widely in their pathogenesis and include infectious and noninfectious conditions. This review focuses on noninfectious granulomatous conditions, with particular emphasis on age-related differences in the onset, epidemiology, clinical manifestations, prognosis, and age-specific management of specific granulomatous disorders. Knowledge of age-specific aspects of granulomatous conditions in adults and children improves both the extent of the diagnostic workup and the management of these patients.

Clinical Characteristics of Sarcoid Arthropathy: A Population-Based Study

OBJECTIVE

The epidemiology and clinical characteristics of sarcoid arthropathy are not well described, as only referral-based studies have been reported. This study aimed to use the data from a geographically well-defined population to characterize the clinical characteristics of sarcoid arthropathy.

METHODS

An inception cohort of patients with incident sarcoidosis in the years 1976-2013 in a geographically well-defined population was identified based on comprehensive individual medical records review. Inclusion required physician diagnosis supported by histopathology and radiologic features of intrathoracic sarcoidosis, compatible clinical presentation, and exclusion of other granulomatous diseases. Patients with joint pain were then identified from this cohort.

RESULTS

In 1976-2013, all 345 incident cases of sarcoidosis were identified. Symptoms of joint pain occurred in 42 patients (mean age 41.2 years, 57.1% female, and 95% white), and 35 patients had swollen joint(s) on physical examination. Most patients had arthralgia prior to the diagnosis of sarcoidosis, with an average time to diagnosis of 21 days. Of the 35 cases, oligoarthritis (2 to 4 joints) was the most common pattern (88% of cases), followed by monoarthritis (6%) and polyarthritis (6%). Ankles were involved in 91% of cases. In the majority of patients (88%), the arthritis resolved within 6 weeks. Classic Lofgren's syndrome was observed in 11 patients (26%).

CONCLUSION

Inflammatory arthritis occurs in a minority of patients with sarcoidosis. Acute oligoarthritis with bilateral ankle involvement was the most common pattern of sarcoid arthropathy. It should be noted that the generalizability of the results may be limited, as the cohort was predominantly white.

Post-9/11 sarcoidosis in WTC-exposed firefighters and emergency medical service workers

INTRODUCTION

The World Trade Center (WTC) disaster released a huge quantity and variety of toxicants into the environment. To-date, studies from each of the three major cohorts of WTC-exposed workers have suggested "greater than expected" numbers of post-9/11 cases in some workers. We undertook this study to estimate the incidence of post-9/11 sarcoidosis in ∼13,000 male firefighters and EMS workers enrolled in The Fire Department of the City of New York (FDNY) WTC Health Program; to compare FDNY incidence to rates from unexposed, demographically similar men in the Rochester Epidemiology Project (REP); and, to examine rates by level of WTC exposure.

METHODS

We calculated incidence of sarcoidosis diagnosed from 9/12/2001 to 9/11/2015, and generated expected sex- and age-specific rates based on REP rates. Standardized incidence ratios (SIR) based on REP rates, and 95% confidence intervals (95% CI) were estimated. Two sensitivity analyses limited cases to those with intra-thoracic symptoms or biopsy confirmation.

RESULTS

We identified 68 post-9/11 cases in the FDNY cohort. Overall, FDNY rates were significantly higher than expected rates (SIR = 2.8; 95% CI = 2.2, 3.6). Including only symptomatic cases, the SIR decreased (SIR = 2.2; 95% CI = 1.5, 3.0), but remained significantly elevated. SIRs ranged from 2.7 (95% CI = 2.0, 3.5) in the lower WTC exposure group to 4.2 (95% CI = 1.9, 8.0) in the most highly exposed.

CONCLUSIONS

We found excess incident post-9/11 sarcoidosis in WTC-exposed workers. Continued surveillance, particularly of those most highly exposed, is necessary to identify those with sarcoidosis and to follow them for possible adverse effects including functional impairments and organ damage.

Radiologic Features of World Trade Center-related Sarcoidosis in Exposed NYC Fire Department Rescue Workers

PURPOSE

An increased incidence of sarcoidosis has been demonstrated in firefighters, supporting the concern that occupational/environmental exposure may pose an etiologic risk factor. This incidence increased further after September 11, 2001 following exposure to World Trade Center (WTC) dust and gases. We review computed tomography (CT) features in this population, comparing the range of findings and physiological correlates with those typically reported in unexposed individuals with pulmonary sarcoidosis.

MATERIALS AND METHODS

With CT imaging we retrospectively identified 46 patients with WTC-related sarcoidosis, between March 18, 2002 and April 5, 2014. Scans were independently reviewed by 2 dedicated thoracic radiologists and assessed for disease patterns and correlation with pulmonary functions.

RESULTS

The majority (37/46; 80%) had symmetric mediastinal and hilar lymphadenopathy. Similarly, most (38/46; 83%) had perilymphatic nodules. Foci of ill-defined ground glass attenuation were present in 6 (13%). Coalescent nodularity was present in 15 (33%). Only 3 (7%) had parenchymal reticulation. A mixed pattern of lung findings was present in 21 (46%). When all forms of parenchymal disease were scored by zonal distribution, 21 (46%) had parenchymal disease predominantly involving mid and upper lungs; 11/46 (24%) had a random distribution without zonal predominance; 6/46 (13%) demonstrated atypical lower zone predominance. Whereas 15/46 (33%) had obstructive airways disease on pulmonary function tests, there were no CT findings that were predictive of obstructive airways disease.

CONCLUSIONS

The majority of cases of WTC-related sarcoidosis demonstrated typical radiographic appearances of sarcoidosis, with symmetric hilar and mediastinal lymphadenopathy and mid to upper lung perilymphatic nodules; these findings were consistent with other previously reported cases of sarcoid-like granulomatous disease in association with various alternate underlying etiologies. There was no correlation between disease patterns or extent on CT and pulmonary function testing, likely at least in part due to the overall mild extent of disease in this population.

Sarcoidosis in an Italian province. Prevalence and environmental risk factors

BACKGROUND AND AIM

Sarcoidosis is a systemic granulomatous inflammatory disease whose causes are still unknown and for which epidemiological data are often discordant. The aim of our study is to investigate prevalence and spatial distribution of cases, and identify environmental exposures associated with sarcoidosis in an Italian province.

METHODS

After georeferentiation of cases, the area under study was subdivided with respect to Municipality and Health Districts and to the altitude in order to identify zonal differences in prevalence. The bioaccumulation levels of 12 metals in lichen tissues were analyzed, in order to determine sources of air pollution. Finally, the analysis of the correlation between metals and between pickup stations was performed.

RESULTS

223 patients were identified (58.3% female and 41.7% male of total) and the mean age was 50.6±15.4 years (53.5±15.5 years for the females and 46.5±14.4 for the males). The mean prevalence was 49 per 100.000 individuals. However, we observed very heterogeneous prevalence in the area under study. The correlations among metals revealed different deposition patterns in lowland area respect to hilly and mountain areas.

CONCLUSIONS

The study highlights a high prevalence of sarcoidosis cases, characterized by a very inhomogeneous and patchy distribution with phenomena of local aggregation. Moreover, the bioaccumulation analysis was an effective method to identify the mineral particles that mostly contribute to air pollution in the different areas, but it was not sufficient to establish a clear correlation between the onset of sarcoidosis and environmental risk factors.

Medical diagnostics for indoor mold exposure

In April 2016, the German Society of Hygiene, Environmental Medicine and Preventative Medicine (Gesellschaft für Hygiene, Umweltmedizin und Präventivmedizin (GHUP)) together with other scientific medical societies, German and Austrian medical societies, physician unions and experts has provided an AWMF (Association of the Scientific Medical Societies) guideline 'Medical diagnostics for indoor mold exposure'. This guideline shall help physicians to advise and treat patients exposed indoors to mold. Indoor mold growth is a potential health risk, even without a quantitative and/or causal association between the occurrence of individual mold species and health effects. Apart from the allergic bronchopulmonary aspergillosis (ABPA) and the mycoses caused by mold, there is only sufficient evidence for the following associations between moisture/mold damages and different health effects: Allergic respiratory diseases, asthma (manifestation, progression, exacerbation), allergic rhinitis, exogenous allergic alveolitis and respiratory tract infections/bronchitis. In comparison to other environmental allergens, the sensitizing potential of molds is estimated to be low. Recent studies show a prevalence of sensitization of 3-10% in the total population of Europe. The evidence for associations to mucous membrane irritation and atopic eczema (manifestation, progression, exacerbation) is classified as limited or suspected. Inadequate or insufficient evidence for an association is given for COPD, acute idiopathic pulmonary hemorrhage in children, rheumatism/arthritis, sarcoidosis, and cancer. The risk of infections from indoor molds is low for healthy individuals. Only molds that are capable to form toxins can cause intoxications. The environmental and growth conditions and especially the substrate determine whether toxin formation occurs, but indoor air concentrations are always very low. In the case of indoor moisture/mold damages, everyone can be affected by odor effects and/or impairment of well-being. Predisposing factors for odor effects can be given by genetic and hormonal influences, imprinting, context and adaptation effects. Predisposing factors for impairment of well-being are environmental concerns, anxieties, conditioning and attributions as well as a variety of diseases. Risk groups that must be protected are patients with immunosuppression and with mucoviscidosis (cystic fibrosis) with regard to infections and individuals with mucoviscidosis and asthma with regard to allergies. If an association between mold exposure and health effects is suspected, the medical diagnosis includes medical history, physical examination, conventional allergy diagnosis, and if indicated, provocation tests. For the treatment of mold infections, it is referred to the AWMF guidelines for diagnosis and treatment of invasive Aspergillus infections. Regarding mycotoxins, there are currently no validated test methods that could be used in clinical diagnostics. From the perspective of preventive medicine, it is important that mold damages cannot be tolerated in indoor environments.

Animal models of sarcoidosis

Sarcoidosis is a debilitating, inflammatory, multiorgan, granulomatous disease of unknown cause, commonly affecting the lung. In contrast to other chronic lung diseases such as interstitial pulmonary fibrosis or pulmonary arterial hypertension, there is so far no widely accepted or implemented animal model for this disease. This has hampered our insights into the etiology of sarcoidosis, the mechanisms of its pathogenesis, the identification of new biomarkers and diagnostic tools and, last not least, the development and implementation of novel treatment strategies. Over past years, however, a number of new animal models have been described that may provide useful tools to fill these critical knowledge gaps. In this review, we therefore outline the present status quo for animal models of sarcoidosis, comparing their pros and cons with respect to their ability to mimic the etiological, clinical and histological hallmarks of human disease and discuss their applicability for future research. Overall, the recent surge in animal models has markedly expanded our options for translational research; however, given the relative early stage of most animal models for sarcoidosis, appropriate replication of etiological and histological features of clinical disease, reproducibility and usefulness in terms of identification of new therapeutic targets and biomarkers, and testing of new treatments should be prioritized when considering the refinement of existing or the development of new models.

Epidemiology of Sarcoidosis in a Prospective Cohort Study of U.S. Women

RATIONALE

Sarcoidosis is a systemic granulomatous and inflammatory disorder that most often involves the lungs but also affects many other organs. Data on sarcoidosis from large epidemiological studies remain scarce.

OBJECTIVES

To evaluate the baseline prevalence and 22-year incidence of sarcoidosis and their associations with demographic and geographic characteristics in a large cohort of U.S. women.

METHODS

The Nurses' Health Study II is a prospective cohort study of U.S. female nurses enrolled in 1989 (aged 25-44 yr, n = 116,430). Data on major illnesses were collected through biennial questionnaires (1989-2011). Cases were identified by the nurses' self-report of physician-diagnosed sarcoidosis. Associations of demographic and geographic characteristics with sarcoidosis were evaluated by logistic regression and Cox models.

MEASUREMENTS AND MAIN RESULTS

A total of 377 sarcoidosis cases were identified. The baseline prevalence was 100/100,000 women. The average annual incidence rate was 11/100,000 during 2,275,028 person-years of follow up. Incidence rate increased with age (P = 0.003), from 9 to 15/100,000 in women aged less than 35 to 55 or more years, respectively. Black women had a higher prevalence (odds ratio, 5.24; 95% confidence interval, 2.87-9.55) and incidence (hazard ratio, 3.80; 95% confidence interval, 2.31-6.24) than white women. Across U.S. regions, more than twofold differences were observed in sarcoidosis prevalence and incidence, with consistently higher rates in the Northeast.

CONCLUSIONS

We provide recent national data on the epidemiology of sarcoidosis among U.S. women. Important differences in prevalence and incidence were observed across U.S. regions. Large epidemiological studies are needed to better understand the causes of the observed demographic and geographic differences in sarcoidosis.

Epidemiology of Sarcoidosis 1946-2013: A Population-Based Study

OBJECTIVE

To characterize the epidemiology of sarcoidosis from 1946 through 2013.

PATIENTS AND METHODS

An inception cohort of patients with incident sarcoidosis from January 1, 1976, through December 31, 2013, in Olmsted County, Minnesota, was identified based on comprehensive individual medical record review. Inclusion required physician diagnosis supported by histopathologic confirmation, radiologic features of intrathoracic sarcoidosis, and a compatible clinical presentation. Data were collected on demographic characteristics, clinical presentation, laboratory investigations, and mortality. The data were augmented with a previously identified cohort of Olmsted County residents diagnosed as having sarcoidosis in 1946-1975. Incidence rates were age and sex adjusted to the 2010 US white population.

RESULTS

A total of 448 incident cases of sarcoidosis were identified (mean age, 44.2 years; 52% women). The annual incidence of sarcoidosis was 10.0 per 100,000 population. The incidence of sarcoidosis increased in women from 1950 to 1960, but otherwise there were no significant calendar year trends. However, the peak age at incidence for women shifted from 40 to 59 years in 1950 to 50 to 69 years in 2010. Similarly, the peak age at incidence for men shifted from 30 to 49 years in 1950 to 40 to 59 years in 2010. Ninety-seven percent of patients had intrathoracic involvement, but only 43% had respiratory symptoms. The overall mortality of patients with sarcoidosis was not different from that of the general population (standardized mortality ratio=0.90; 95% CI, 0.74-1.08).

CONCLUSION

Sarcoidosis occurred in approximately 10 persons per 100,000 per year. Most of the patients had intrathoracic involvement, although less than half had respiratory symptoms. Overall mortality was not different from that of the general population.

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.

[Cutaneous manifestations of sarcoidosis]

Sarcoidosis is a systemic granulomatous disorder of unknown aetiology. Its dermatological manifestations are extremely polymorphous. They are normally classed as either specific lesions, comprising granulomas, which are generally chronic, or non-specific lesions, principally acute erythema nodosum. These signs are seen in around 25% of sarcoidosis patients. The disease may be heralded by a skin disorder. Diagnosis of cutaneous sarcoidosis provides the clinician with three problems: screening for a visceral site of the disease, determination of the prognosis, and long-term management with regular monitoring coupled with suitable therapy in the event of cosmetic or functional impairment.

Exposure to a Mycobacterial Antigen, ESAT-6, Exacerbates Granulomatous and Fibrotic Changes in a Multiwall Carbon Nanotube Model of Chronic Pulmonary Disease

Recent studies suggest additive effects of environmental pollutants and microbial antigens on respiratory disease. We established a granuloma model in which instilled multiwall carbon nanotubes (MWCNT) elicit granulomatous pathology. We hypothesized that mycobacterial antigen ESAT-6, a T cell activator associated with tuberculosis and sarcoidosis, might alter pathology. Wild-type C57Bl/6 mice received MWCNT with or without ESAT-6 peptide. Controls received vehicle (surfactant-PBS) or ESAT-6 alone. Mice were evaluated 60 days later for granulomas, fibrosis, and bronchoalveolar lavage (BAL) cell expression of inflammatory mediators (CCL2, MMP-12, and Osteopontin). Results indicated increased granulomas, fibrosis, and inflammatory mediators in mice receiving the combination of MWCNT+ESAT-6 compared to MWCNT or vehicle alone. ESAT-6 alone showed no significant effect on these pathological endpoints. However, CD3 (+) lymphocyte infiltration of lung tissue increased with MWCNT+ESAT-6 versus MWCNT alone. Findings suggest that concurrent exposure to microbial antigen and MWCNT exacerbates chronic pulmonary disease.

Neurosarcoidosis

Neurosarcoidosis is known as the great mimicker and may appear similar to lymphoma, multiple sclerosis, and other diseases affecting the nervous system. Although definitive diagnosis requires histologic confirmation of the affected neural tissue, characteristic clinical manifestations, gadolinium-enhanced MRI patterns and specific cerebrospinal fluid findings can help support the diagnosis in the absence of neural biopsy. An understanding of the common clinical presentations and diagnostic findings is central to the evaluation and management of neurosarcoidosis.