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

Ventricular predominance in biventricular arrhythmogenic cardiomyopathy: Should new subtype criteria be recognized?

Arrhythmogenic cardiomyopathy is a biventricular disease in which the effect on the left ventricle can be either equivalent to or more severe than that on the right ventricle. It is a rare disease due to its low reported prevalence and typically becomes clinically evident during the second to fourth decade of life. It represents 4% of sudden cardiac death cases referred for autopsy and 10% of cases of unexplained cardiac arrest. We present a challenging case report of a 68-year-old man who arrived at the emergency room with chest discomfort, palpitations, and light-headedness before a syncopal episode with urinary incontinence. During monitoring, ventricular tachycardia was detected and was treated with cardioversion. However, a follow-up electrocardiogram revealed low QRS voltages in limb leads and T-wave inversion in the left precordial leads. The patient underwent a transthoracic echocardiogram and a gadolinium-based magnetic resonance imaging study to evaluate the possibility of acute decompensated heart failure. Both imaging studies revealed low ejection fraction and systolic dysfunction in both right and left ventricles. Furthermore, in the late gadolinium enhancement study, extensive left ventricular subepicardial enhancement with septal predominance in a ring pattern and an irregular morphology of the right ventricular free wall were observed. A diagnosis of biventricular arrhythmogenic cardiomyopathy was established based on the 2020 Padua Criteria. Although there is not a recognized classification within these criteria to establish its subtype, in our case there was a left ventricular predominance due to the presence of additional left ventricular categories.

Predictors of Mortality in Sarcoidosis

Sarcoidosis is a systemic granulomatous disorder that affects individuals of all racial/ethnic origins and occurs at any time of life. Spontaneous remission is frequent and may occur in 2 of 3 patients, while the remaining cases have chronic, progressive disease, with some patients presenting with organ- and life-threatening involvements. Many reports have investigated which features may be related to poor outcomes in patients with sarcoidosis. Pulmonary hypertension and respiratory failure from pulmonary fibrosis are the most common complications associated with the cause of death in sarcoidosis. Other major causes of death include cardiac, neurologic, hepatic involvement, and hemoptysis from aspergilloma.

Fibrotic Pulmonary Sarcoidosis

Fibrotic pulmonary sarcoidosis (fPS) affects about 20% of patients. fPS carries a significant morbidity and mortality. However, its prognosis is highly variable, depending mainly on fibrosis extent, functional impairment severity, and the development of pulmonary hypertension. Moreover, fPS outcomes are also influenced by several other complications, including acute exacerbations, and infections. fPS natural history is unknown, in particular regarding the risk of progressive self-sustaining fibrosis. The management of fPS is challenging, including anti-inflammatory treatment if granulomatous activity persists, rehabilitation, and in highly selected patients antifibrotic treatment and lung transplantation.

Examination of eQTL Polymorphisms Associated with Increased Risk of Progressive Complicated Sarcoidosis in European and African Descent Subjects

Background

A limited pool of SNPs are linked to the development and severity of sarcoidosis, a systemic granulomatous inflammatory disease. By integrating genome-wide association studies (GWAS) data and expression quantitative trait loci (eQTL) single nuclear polymorphisms (SNPs), we aimed to identify novel sarcoidosis SNPs potentially influencing the development of complicated sarcoidosis.

Methods

A GWAS (Affymetrix 6.0) involving 209 African-American (AA) and 193 European-American (EA, 75 and 51 complicated cases respectively) and publicly-available GWAS controls (GAIN) was utilized. Annotation of multi-tissue eQTL SNPs present on the GWAS created a pool of ~46,000 eQTL SNPs examined for association with sarcoidosis risk and severity (Logistic Model, Plink). The most significant EA/AA eQTL SNPs were genotyped in a sarcoidosis validation cohort (n=1034) and cross-validated in two independent GWAS cohorts.

Results

No single GWAS SNP achieved significance (p<1x10-8), however, analysis of the eQTL/GWAS SNP pool yielded 621 eQTL SNPs (p<10-4) associated with 730 genes that highlighted innate immunity, MHC Class II, and allograft rejection pathways with multiple SNPs validated in an independent sarcoidosis cohort (105 SNPs analyzed) (NOTCH4, IL27RA, BTNL2, ANXA11, HLA-DRB1). These studies confirm significant association of eQTL/GWAS SNPs in EAs and AAs with sarcoidosis risk and severity (complicated sarcoidosis) involving HLA region and innate immunity.

Conclusion

Despite the challenge of deciphering the genetic basis for sarcoidosis risk/severity, these results suggest that integrated eQTL/GWAS approaches may identify novel variants/genes and support the contribution of dysregulated innate immune responses to sarcoidosis severity.

The role of the host-microbiome and metabolomics in sarcoidosis

Sarcoidosis is a complex inflammatory fibrotic disease that affects multiple organ systems. It is characterized by the infiltration of lymphocytes and mononuclear phagocytes, which form non-caseating granulomas in affected organs. The lungs and intrathoracic lymph nodes are the most commonly affected organs. The underlying cause of sarcoidosis is unknown, but it is believed to occur in genetically predisposed individuals who are exposed to pathogenic organisms, environmental contaminants, or self and non-self-antigens. Recent research has suggested that the microbiome may play a role in the development of respiratory conditions, including sarcoidosis. Additionally, metabolomic studies have identified potential biomarkers for monitoring sarcoidosis progression. This review will focus on recent microbiome and metabolomic findings in sarcoidosis, with the goal of shedding light on the pathogenesis and possible diagnostic and therapeutic approaches.

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.

Sarcoidosis and burn pit exposure in military deployers to Iraq, Afghanistan, and Southwest Asia

BACKGROUND AND AIM

Inhalational exposures have been hypothesized to play a role in the pathogenesis of sarcoidosis. Herein, we describe a cohort of US Military personnel diagnosed with sarcoidosis during or after deployment to Southwest Asia and Afghanistan, who experienced complex inhalational exposures to burn-pits and desert dust.

METHODS

Consecutive military personnel at four sub-specialty clinics across the United States were screened for deployment to Southwest Asia and Afghanistan and diagnosis of sarcoidosis based on 1999 ATS/ERS/WASOG Statement on Sarcoidosis. Detailed demographic, deployment and exposure data was collected. The data combined was analyzed after de-identification and local IRB approval.

RESULTS

Twenty-one patients met our case definition. Seventeen patients were male and 62% had extrapulmonary involvement, including 38% with musculoskeletal involvement.  Conclusions: Our study suggests that the sarcoidosis in military personnel to Southwest Asia can be diagnosed many years after deployment. To our knowledge, this is the first case series to describe a group of military personnel diagnosed with sarcoidosis and exposures specific to military deployment to Southwest Asia.

Identification of Environmental Exposures Associated with Risk of Sarcoidosis in African Americans

Rationale: Sarcoidosis is a racially disparate granulomatous disease likely caused by environmental exposures, genes, and their interactions. Despite increased risk in African Americans, few environmental risk factor studies in this susceptible population exist. Objectives: To identify environmental exposures associated with the risk of sarcoidosis in African Americans and those that differ in effect by self-identified race and genetic ancestry. Methods: The study sample comprised 2,096 African Americans (1,205 with and 891 without sarcoidosis) compiled from three component studies. Unsupervised clustering and multiple correspondence analyses were used to identify underlying clusters of environmental exposures. Mixed-effects logistic regression was used to evaluate the association of these exposure clusters and the 51 single-component exposures with risk of sarcoidosis. A comparison case-control sample of 762 European Americans (388 with and 374 without sarcoidosis) was used to assess heterogeneity in exposure risk by race. Results: Seven exposure clusters were identified, five of which were associated with risk. The exposure cluster with the strongest risk association was composed of metals (P < 0.001), and within this cluster, exposure to aluminum had the highest risk (odds ratio, 3.30; 95% confidence interval [95% CI], 2.23-4.09; P < 0.001). This effect also differed by race (P < 0.001), with European Americans having no significant association with exposure (odds ratio, 0.86; 95% CI, 0.56-1.33). Within African Americans, the increased risk was dependent on genetic African ancestry (P = 0.047). Conclusions: Our findings support African Americans having sarcoidosis environmental exposure risk profiles that differ from those of European Americans. These differences may underlie racially disparate incidence rates that are partially explained by genetic variation differing by African ancestry.

Genome-wide association study identifies multiple HLA loci for sarcoidosis susceptibility

Sarcoidosis is a complex systemic disease. Our study aimed to (1) identify novel alleles associated with sarcoidosis susceptibility; (2) provide an in-depth evaluation of HLA alleles and sarcoidosis susceptibility and (3) integrate genetic and transcription data to identify risk loci that may more directly impact disease pathogenesis. We report a genome-wide association study of 1335 sarcoidosis cases and 1264 controls of European descent (EA) and investigate associated alleles in a study of African Americans (AA: 1487 cases and 1504 controls). The EA and AA cohort was recruited from multiple United States sites. HLA alleles were imputed and tested for association with sarcoidosis susceptibility. Expression quantitative locus and colocalization analysis were performed using a subset of subjects with transcriptome data. Forty-nine SNPs in the HLA region in HLA-DRA, -DRB9, -DRB5, -DQA1 and BRD2 genes were significantly associated with sarcoidosis susceptibility in EA, rs3129888 was also a risk variant for sarcoidosis in AA. Classical HLA alleles DRB1*0101, DQA1*0101 and DQB1*0501, which are highly correlated, were also associated with sarcoidosis. rs3135287 near HLA-DRA was associated with HLA-DRA expression in peripheral blood mononuclear cells and bronchoalveolar lavage from subjects and lung tissue and whole blood from GTEx. We identified six novel SNPs (out of the seven SNPs representing the 49 significant SNPs) and nine HLA alleles associated with sarcoidosis susceptibility in the largest EA population. We also replicated our findings in an AA population. Our study reiterates the potential role of antigen recognition and/or presentation HLA class II genes in sarcoidosis pathogenesis.

Sarcoidosis and Autoimmune Inflammatory Syndrome Induced by Adjuvants

Currently, sarcoidosis remains one of the diseases with unknown etiology, which significantly complicates its diagnosis and treatment. Various causes of sarcoidosis have been studied for many years. Both organic and inorganic trigger factors, provoking the development of granulomatous inflammation are considered. However, the most promising and evidence-based hypothesis is the development of sarcoidosis as an autoimmune disease, provoked by various adjuvants in genetic predisposed individuals. This concept fits into the structure of the autoimmune/inflammatory syndrome, induced by adjuvants (ASIA) that was proposed in 2011 by Professor Shoenfeld Y. In this paper, the authors reveal the presence of major and minor ASIA criteria for sarcoidosis, propose a new concept of the course of sarcoidosis within the framework of ASIA, and point out the difficulties in creating a model of the disease and the selection of therapy. It is obvious that the data obtained not only bring us closer to understanding the nature of sarcoidosis, but also potentiate new studies confirming this hypothesis by obtaining a model of the disease.

Environmental and occupational exposures in interstitial lung disease

PURPOSE OF REVIEW

We highlight recent advances in the understanding of how environmental and occupational exposures increase the risk of developing interstitial lung disease (ILD), and how to evaluate a patient for potential exposures.

RECENT FINDINGS

A review of emerging literature suggests that environmental and occupational exposures can be directly causal, as in the case of the pneumoconioses and smoking-related ILDs, or one of many contributors to disease, as in the case of idiopathic pulmonary fibrosis (IPF). Regardless of the level of association, exposures are clearly prevalent across all ILD subtypes studied.

SUMMARY

Inhalational exposures are increasingly recognized as an important component in the development of ILDs, and novel exposure-disease associations continue to be discovered. These exposures represent potential opportunities for further understanding the pathobiology of disease and for the prevention of these often progressive and debilitating disorders. Prospective, comprehensive data collection regarding occupational and environmental exposures are needed in ILD patients to fully elucidate specific antigens and their relationships to disease incidence and outcomes. Systematically collected exposure information will also inform potential interventions to remediate exposures and thus mitigate the course of frequently progressive and fatal diseases.

Inhalational exposures in patients with fibrotic interstitial lung disease: Presentation, pulmonary function and survival in the Canadian Registry for Pulmonary Fibrosis

BACKGROUND AND OBJECTIVE

Inhalational exposures are a known cause of interstitial lung disease (ILD), but little is understood about their prevalence across ILD subtypes and their relationship with pulmonary function and survival.

METHODS

Patients with fibrotic ILD were identified from the multicentre Canadian Registry for Pulmonary Fibrosis. Patients completed questionnaires regarding ILD-related occupational and environmental exposures. The relationship between exposures and the outcomes of baseline age, gender, family history, pulmonary function and survival was analysed using linear and logistic regression models, linear mixed-effect regression models and survival analysis using multivariable Cox proportional hazards along with the log-rank test.

RESULTS

There were 3820 patients included in this study, with 2385 (62%) having ILD-related inhalational exposure. Exposed patients were younger, particularly in the idiopathic pulmonary fibrosis subgroup. Inhalational exposure was associated with male gender (adjusted OR 1.46, 95% CI 1.28-1.68, p < 0.001) and family history of pulmonary fibrosis (adjusted OR 1.73, 95% CI 1.40-2.15, p < 0.001). Patients with any inhalational exposure had improved transplant-free survival (hazard ratio 0.81, 95% CI 0.71-0.92, p = 0.001); this effect persisted across diagnostic subtypes. The relationship between exposures and annual change in forced vital capacity varied by ILD subtype.

CONCLUSION

Patients with fibrotic ILD report high prevalence of inhalational exposures across ILD subtypes. These exposures were associated with younger age at diagnosis, male gender and family history of pulmonary fibrosis. Identification of an inhalational exposure was associated with a survival benefit. These findings suggest that inhaled exposures may impact clinical outcomes in patients with ILD, and future work should characterize the mechanisms underlying these relationships.

Occupational and environmental exposures in the Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS) study

INTRODUCTION

Sarcoidosis is a granulomatous disorder thought to be caused by exposures in genetically susceptible individuals. This study investigated whether specific exposures were associated with different sarcoidosis phenotypes.

METHODS

Extensive demographic, occupational and environmental exposure data was analyzed from subjects enrolled in the NHLBI Genomic Research in Alpha-1 Antitrypsin Deficiency and Sarcoidosis (GRADS) study.

RESULTS

In patients with sarcoidosis, radiation exposure was significantly associated with an increased risk of cardiac sarcoidosis versus non-cardiac sarcoidosis. No exposures were significantly associated with pulmonary only disease versus extrapulmonary disease with or without pulmonary involvement, Scadding Stage II/III/IV versus Scadding Stage 0/I, acute or remitting disease versus non-acute or non-remitting disease, nor chronic versus non-chronic disease. Although not reaching statistically significance after adjustment for multiple comparisons, there were a number of exposures associated with specific disease phenotypes, including exposures where relationships to sarcoidosis have previously been described such as rural exposures and pesticide exposures.

CONCLUSIONS

Radiation exposure may be a risk factor for cardiac sarcoidosis. Other exposures may also be associated with specific phenotypes and should be further explored. The study was limited by small groups of exposed subjects for individual exposures and multiple comparisons. The development of novel and innovative exposure assessment tools is needed.

Clinical characteristics of sarcoidosis patients in Belgium

BACKGROUND

Sarcoidosis is a non-caseating granulomatous disease, mostly affecting previously healthy persons in their fourth and fifth decade. In Belgium, there is a paucity of epidemiological data concerning sarcoidosis and it is unknown to what respect national data on sarcoidosis relates to the global epidemiology of the disease.

OBJECTIVES

In this cohort study we describe the patient population in an academic center of reference, serving both as a regional care center and a center for a tertiary referral.

METHODS

We collected epidemiological data among 234 consecutive patients consulting the outpatient sarcoidosis clinic during a two-year time period. We manually explored the electronic patient file for data retrieval.

RESULTS

Out of the 234 patients, 140 are male (60%) and 94 are female (40%) patients. Forced vital capacity showed a median decline of 2% during follow-up, whereas median diffusion capacity increased with 4% over the same period of time. Within our study cohort, we observed a preponderance in employment as construction workers (14%), the chemical industry (6%) and in the metal processing industry (6%).

CONCLUSION

The current study reports on epidemiological findings among the largest cohort of sarcoidosis patients in Belgium published to date.

Graphical abstract [Figure: see text].

Sarcoidosis in Northern Ontario hard-rock miners: A case series

Sarcoidosis is a rare multisystem granulomatous disease traditionally considered to be of unknown etiology. The notion that sarcoidosis has no known cause is called into question with the increasing number of case reports and epidemiologic studies showing associations between occupational exposures and disease published in the past 10-20 years. Occupational exposures for which associations are strongest and most consistent are silica and other inorganic dusts, World Trade Center (WTC) dust, and metals. Occupations identified as at-risk for sarcoidosis include construction workers; iron-foundry and diatomaceous earth workers; WTC emergency responders; and metal workers. We report here 12 cases of sarcoidosis in a cohort of hard-rock miners in Northern Ontario, Canada. To our knowledge sarcoidosis has not been reported previously in hard-rock miners. The cases are all male and Caucasian, with average age 74 years. At the time of diagnosis, two were never smokers; six, former smokers; and four, current smokers. Five have extrapulmonary sarcoidosis: two cardiac and three endocrine (hypercalciuria). Using occupational histories and air sampling data from the gold, uranium, and base-metal mines in which they worked, we examined exposure of each case to respirable crystalline silica (RCS). The annual mean RCS exposure for the 12 cases was 0.14 mg/m³ (range: 0.06-1.3 mg/m³ ); and the mean cumulative RCS exposure was 1.93 mg/m³  years (range: 0.64-4.03 mg/m³  years). We also considered their exposure to McIntyre Powder, an aluminum powder used for silicosis prophylaxis.

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: A nationwide registry-based study of incidence, prevalence and diagnostic work-up

INTRODUCTION

The primary objective was to evaluate the prevalence and incidence of sarcoidosis, and secondly, to evaluate differences in incidence by age at diagnosis, gender, region, calendar year and treatment and to evaluate sarcoidosis-related diagnostic work-up.

METHODS

Patients diagnosed with sarcoidosis from 2001 to 2015 and information on diagnostic procedures three months before and after initial diagnosis were identified in the Danish National Patient Register. Incidence proportion and prevalence proportion were calculated using the total population count of Danish citizens.

RESULTS

We identified 8545 sarcoidosis cases. Mean age was 46.0 ± 15.0 years, male gender was overrepresented (56.2%) and systemic corticosteroid was initiated in 46% of cases. The prevalence was 77 per 100,000 citizens in 2015. From 2001 to 2015, the incidence varied from 11.3 to 14.8 per 100,000 per year. The age-associated incidence peaked at 30-39 years in both men (23.6 per 100,000 per year) and women (15.0 per 100,000 per year). Incidence varied from 10.4 to 15.7 per 100,000 per year among regions. In particular, the share of bronchoscopies and chest-computed tomography were high in the region with the highest incidence and low in the region with the lowest incidence. Invasive procedures were more frequently performed in patients treated with systemic corticosteroid.

CONCLUSION

We find an increasing incidence and prevalence of sarcoidosis, with a peak incidence for both men and women between 30 and 39 years of age. The share of procedures performed seems to correlate well with incidence and disease severity.

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.

Characteristics and Prevalence of Domestic and Occupational Inhalational Exposures Across Interstitial Lung Diseases

BACKGROUND

Inhalational exposures are increasingly recognized as contributing factors in interstitial lung disease (ILD). However, the characteristics of both exposures and exposed patients are not well understood. We hypothesized that domestic and occupational inhalational exposures would be common and associated with differences in demographics, clinical characteristics, and transplant-free survival in patients with all forms of ILD.

RESEARCH QUESTION

What is the prevalence of inhalational exposures across all ILD diagnoses, and are these exposures associated with differences in demographics, clinical characteristics, and transplant-free survival?

STUDY DESIGN AND METHODS

Patients from a tertiary ILD clinic underwent an interview designed to capture inhalational exposures including occupational, home, hobbies, and tobacco. Demographic and survival data were collected from the electronic medical record. Survival analysis was performed using Cox regression to compare exposed vs unexposed patients and adjusted for gender-age-physiology score and smoking.

RESULTS

One hundred and fifty-six patients seen between May and October 2018 were analyzed. Patients had a wide variety of multidisciplinary diagnoses, with a minority of patients with hypersensitivity pneumonitis (14%). One hundred and one patients (65%) had potentially relevant inhalational exposures. More men than women had a history of any exposure (82% vs 51%; P < .001), occupational exposure (66% vs 14%, P < .001), and multiple exposures (56% vs 26%, P < .001), respectively. White race was associated with bird and hobby exposure. Patients with any exposure had worse transplant-free survival (unadjusted hazard ratio, 2.58; 95% CI, 1.13-5.92; P = .025), but this was not statistically significant after adjustment (hazard ratio, 1.82; 95% CI, 0.77-4.27; P = .17).

INTERPRETATION

A standardized interview revealed most patients across all types of ILD had potentially relevant inhalational exposures. Exposures were markedly different based on demographics and were associated with worse transplant-free survival, but this survival difference was not significant after multivariable adjustment. Identification and avoidance of exposures represent actionable targets in ILD management.

Silicosis: An Update and Guide for Clinicians

This overview provides an update on silicosis epidemiology with review of exposures and emerging trends in acute and accelerated silicosis in the twenty-first century. The silicosis epidemics in mining, denim sandblasting, and engineering stone industries are highlighted. Clinical presentations of silicosis and silica-related conditions such as autoimmune, kidney, and mycobacterial disease, as well as lung cancer, are discussed. Important aspects of the new OSHA 2017 Silica Standard are presented. This review also includes practical guidance for clinicians to address questions that may arise when evaluating silica-exposed patients and to the public health responses needed following a diagnosis of silica-related disease.

Sarcoidosis: a prospective observational cohort from Northern Alberta

INTRODUCTION

Sarcoidosis is a multi-system disease reported to occur with a higher incidence in Alberta than many other health jurisdictions within and outside of Canada. The reasons for this higher incidence are currently not known. Exposure to beryllium can result in a clinically and radiologically identical disease to sarcoidosis. The purpose of our study was to identify patterns with potential occupational or environmental exposures to beryllium amongst individuals with sarcoidosis in Alberta through a tertiary referral center.

METHODS

A prospective observational study was carried out at the University of Alberta Hospital. Patients with confirmed sarcoidosis (stages 0-4) were recruited from subspecialty clinics (Respirology, Cardiology, Neurology and Occupational Health). A predetermined list of industries thought to involve potentially relevant exposures for the development of sarcoidosis was used to capture current and previous exposure history. Results were entered into a database and where possible verified by comparing with existing electronic medical records (including histories, physical examination, diagnostic imaging and physiology).

RESULTS

A total of 45 patients were recruited, 25 men and 20 women. Of these, 84% of participants reported working in or being exposed to an industry/environment suspected of contributing to development of sarcoidosis over their lifetime. The most frequently reported exposures were within farming and agriculture (27%), oil and gas (20%), metalworking and handling animals (18%).

CONCLUSIONS

Amongst this cohort, a high proportion reported working with a potentially relevant exposure. Individuals being assessed for sarcoidosis should have their most responsible physician elicit a detailed work and environmental history. (Sarcoidosis Vasc Diffuse Lung Dis 2020; 37 (4): e2020014).

Sentinel approach to detect emerging causes of work-related respiratory diseases

BACKGROUND

The world of work is continually changing, and this could result in new and emerging risks being introduced, including those that may cause work-related respiratory diseases (WRRD).

AIMS

To describe recently emerging and new cases of WRRD and the relevant methodology using data in a national occupational respiratory disease surveillance scheme in the UK.

METHODS

Incident cases of respiratory diseases reported by physicians to the Surveillance of Work-related and Occupational Respiratory Disease (SWORD) between January 2015 and December 2017 were included. Potentially emerging respiratory hazards manifesting in SWORD data were identified with the following hierarchical approach: (i) new respiratory disease not previously associated with work, (ii) specific exposure/agent not previously associated with WRRD and (iii) industry and/or occupation not previously associated with WRRD.

RESULTS

A total of 1215 cases of WRRD were reported to SWORD between January 2015 and December 2017. No new WRRD were identified. Thirteen potentially emerging causes of occupational asthma were identified, including exposures to agents such as ninhydrin. Four potential new causes were identified for interstitial pneumonia, which included wood and brass dust. Two potentially emerging causes of WRRD were identified for inhalational accidents (green coffee and nitrocellulose), hypersensitivity pneumonitis (diphenylmethane diisocyanate and salami mould), rhinitis (morphine and Amaranthus quitensis) and sarcoidosis (prions and horses).

CONCLUSIONS

Continuous monitoring and reporting of any new work-related disease is a critical function of any occupational disease reporting scheme. Potential emerging causes of work-related health risks have been identified by using a simple and systematic way of detecting emerging causes of WRRDs.

The Occupational Burden of Nonmalignant Respiratory Diseases. An Official American Thoracic Society and European Respiratory Society Statement

Rationale: Workplace inhalational hazards remain common worldwide, even though they are ameliorable. Previous American Thoracic Society documents have assessed the contribution of workplace exposures to asthma and chronic obstructive pulmonary disease on a population level, but not to other chronic respiratory diseases. The goal of this document is to report an in-depth literature review and data synthesis of the occupational contribution to the burden of the major nonmalignant respiratory diseases, including airway diseases; interstitial fibrosis; hypersensitivity pneumonitis; other noninfectious granulomatous lung diseases, including sarcoidosis; and selected respiratory infections. Methods: Relevant literature was identified for each respiratory condition. The occupational population attributable fraction (PAF) was estimated for those conditions for which there were sufficient population-based studies to allow pooled estimates. For the other conditions, the occupational burden of disease was estimated on the basis of attribution in case series, incidence rate ratios, or attributable fraction within an exposed group. Results: Workplace exposures contribute substantially to the burden of multiple chronic respiratory diseases, including asthma (PAF, 16%); chronic obstructive pulmonary disease (PAF, 14%); chronic bronchitis (PAF, 13%); idiopathic pulmonary fibrosis (PAF, 26%); hypersensitivity pneumonitis (occupational burden, 19%); other granulomatous diseases, including sarcoidosis (occupational burden, 30%); pulmonary alveolar proteinosis (occupational burden, 29%); tuberculosis (occupational burden, 2.3% in silica-exposed workers and 1% in healthcare workers); and community-acquired pneumonia in working-age adults (PAF, 10%). Conclusions: Workplace exposures contribute to the burden of disease across a range of nonmalignant lung conditions in adults (in addition to the 100% burden for the classic occupational pneumoconioses). This burden has important clinical, research, and policy implications. There is a pressing need to improve clinical recognition and public health awareness of the contribution of occupational factors across a range of nonmalignant respiratory diseases.

Female workers' silicosis diagnosis delayed due to gender bias

After excluding alternative explanations, a silicosis diagnosis is based on the combination of appropriate silica exposure history and compatible clinical, radiological and occasionally pathological findings. Not taking appropriate occupational history by a physician may cause a misdiagnosis or underdiagnosis of silicosis. Herein, we present a female worker in a small-scale sandblasting factory who worked as a controller. Her silicosis diagnosis was established 10 years after her first symptoms, and she underwent invasive procedures due to a lack of inquiry about her occupational history. Gender bias may be one of the reasons that her occupational history was not taken.

In-silico modeling of granulomatous diseases

PURPOSE OF REVIEW

The pathogenesis of genetically complex granulomatous diseases, such as sarcoidosis and latent tuberculosis, remains largely unknown. With the recent advent of more powerful research tools, such as genome-wide expression platforms, comes the challenge of making sense of the enormous data sets so generated. This manuscript will provide demonstrations of how in-silico (computer) analysis of large research data sets can lead to novel discoveries in the field of granulomatous lung disease.

RECENT FINDINGS

The application of in-silico research tools has led to novel discoveries in the fields of noninfectious (e.g., sarcoidosis) and infectious granulomatous diseases. Computer models have identified novel disease mechanisms and can be used to perform 'virtual' experiments rapidly and at low cost compared with conventional laboratory techniques.

SUMMARY

Granulomatous lung diseases are extremely complex, involving dynamic interactions between multiple genes, cells, and molecules. In-silico interpretation of large data sets generated from new research platforms that are capable of comprehensively characterizing and quantifying pools of biological molecules promises to rapidly accelerate the rate of scientific discovery in the field of granulomatous lung disorders.

A Novel In Vitro Human Granuloma Model of Sarcoidosis and Latent Tuberculosis Infection

Many aspects of pathogenic granuloma formation are poorly understood, requiring new relevant laboratory models that represent the complexity (genetics and diversity) of human disease. To address this need, we developed an in vitro model of granuloma formation using human peripheral blood mononuclear cells (PBMCs) derived from patients with active sarcoidosis, latent tuberculosis (TB) infection (LTBI), or normal healthy control subjects. PBMCs were incubated for 7 days with uncoated polystyrene beads or beads coated with purified protein derivative (PPD) or human serum albumin. In response to PPD-coated beads, PBMCs from donors with sarcoidosis and LTBI formed robust multicellular aggregates resembling granulomas, displaying a typical T-helper cell type 1 immune response, as assessed by cytokine analyses. In contrast, minimal PBMC aggregation occurred when control PBMCs were incubated with PPD-coated beads, whereas the response to uncoated beads was negligible in all groups. Sarcoidosis PBMCs responded to human serum albumin-coated beads with modest cellular aggregation and inflammatory cytokine release. Whereas the granuloma-like aggregates formed in response to PPD-coated beads were similar for sarcoidosis and LTBI, molecular profiles differed significantly. mRNA expression patterns revealed distinct pathways engaged in early granuloma formation in sarcoidosis and LTBI, and they resemble molecular patterns reported in diseased human tissues. This novel in vitro human granuloma model is proposed as a tool to investigate mechanisms of early granuloma formation and for preclinical drug discovery research of human granulomatous disorders. Clinical trial registered with www.clinicaltrials.gov (NCT01857401).

Sarcoidosis-related mortality in France: a multiple-cause-of-death analysis

We evaluated mortality rates and underlying causes of death among French decedents with sarcoidosis from 2002 to 2011.We used data from the French Epidemiological Centre for the Medical Causes of Death to 1) calculate sarcoidosis-related mortality rates, 2) examine differences by age and gender, 3) determine underlying and nonunderlying causes of death, 4) compare with the general population (observed/expected ratios), and 5) analyse regional differences.1662 death certificates mentioning sarcoidosis were recorded. The age-standardised mortality rate was 3.6 per million population and significantly increased over the study period. The mean age at death was 70.4 years (versus 76.2 years for the general population). The most common underlying cause of death was sarcoidosis. Sarcoidosis decedents were more likely to be males when aged <65 years. When sarcoidosis was the underlying cause of death, the main other mentions on death certificates were chronic respiratory and cardiovascular diseases. The overall observed/expected ratio was >1 for infectious disease, tuberculosis and chronic respiratory disease, and <1 for neoplasms. We observed a north-south gradient of age-standardised mortality ratio at the country level.Despite the limitation of possibly capturing the more severe cases of sarcoidosis, this study may help define and prioritise preventive interventions.