Hypersensitivity pneumonitis due to molds in a saxophone player

Clinical Manifestations of Human Exposure to Fungi

Biological particles, along with inorganic gaseous and particulate pollutants, constitute an ever-present component of the atmosphere and surfaces. Among these particles are fungal species colonizing almost all ecosystems, including the human body. Although inoffensive to most people, fungi can be responsible for several health problems, such as allergic fungal diseases and fungal infections. Worldwide fungal disease incidence is increasing, with new emerging fungal diseases appearing yearly. Reasons for this increase are the expansion of life expectancy, the number of immunocompromised patients (immunosuppressive treatments for transplantation, autoimmune diseases, and immunodeficiency diseases), the number of uncontrolled underlying conditions (e.g., diabetes mellitus), and the misusage of medication (e.g., corticosteroids and broad-spectrum antibiotics). Managing fungal diseases is challenging; only four classes of antifungal drugs are available, resistance to these drugs is increasing, and no vaccines have been approved. The present work reviews the implications of fungal particles in human health from allergic diseases (i.e., allergic bronchopulmonary aspergillosis, severe asthma with fungal sensitization, thunderstorm asthma, allergic fungal rhinosinusitis, and occupational lung diseases) to infections (i.e., superficial, subcutaneous, and systemic infections). Topics such as the etiological agent, risk factors, clinical manifestations, diagnosis, and treatment will be revised to improve the knowledge of this growing health concern.

Bitesize Epidemiology for General Awareness of All Students - I

This is the first part of a two-part series article. Recently, we have been in the middle of a difficult time due to the Covid-19 pandemic. Pandemics or global epidemics are not new to humankind; they have occurred many times in history. The discourse of epidemiology describes mainly the causal factors which need to be mitigated to prevent or combat the effects of epidemics. In epidemiology, we are not concerned for a person, but rather every individual globally, to make life healthier for all. In this article, we will discuss the basics of epidemiological practice that scientists have used for centuries to prevent epidemics with great results. Overall, we plan for better global health aided by epidemiology.

Questionnaires or Serum Immunoglobulin G Testing in the Diagnosis of Hypersensitivity Pneumonitis among Patients with Interstitial Lung Disease

Rationale: Hypersensitivity pneumonitis (HP) results from exposure to a variety of stimuli, which are challenging to identify. Questionnaires and serum immunoglobulin G (IgG) testing are methods to identify potentially causative exposures.Objectives: To perform a systematic review to determine the usefulness of questionnaires and serum IgG testing in identifying exposures that may have caused HP.Methods: This systematic review informed an international, multidisciplinary panel that developed a clinical practice guideline on the diagnosis of HP for the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax. MEDLINE, the Cochrane Library, and EMBASE were searched from January 1946 to October 2019 for studies that used a questionnaire or serum IgG testing to identify exposures that may have caused HP. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to appraise the quality of the evidence.Results: Searches identified 1,141 and 926 potentially relevant articles for questionnaires and serum IgG testing, respectively. The full texts of 32 and 49 articles, respectively, were reviewed. Two observational studies for questionnaires and 15 accuracy studies for serum IgG testing were selected. Questionnaires were better at detecting potentially relevant exposures than clinical history (100% vs. 26%; risk ratio [RR], 3.80; 95% confidence interval [95% CI], 1.79-8.06) and serum IgG testing (100% vs. 63%; RR, 1.58; 95% CI, 1.12-2.23) but did not differ from serum IgG testing plus bronchial challenge testing (59% vs. 65%; RR, 0.90; 95% CI, 0.65-1.24). Longer, detailed questionnaires were more likely to lead to identification of potential exposures. Only 70% of potential exposures identified by questionnaires were subsequently confirmed by environmental testing. Serum IgG testing distinguished HP from healthy exposed and unexposed control subjects with high sensitivity (90% and 92%, respectively) and high specificity (91% and 100%, respectively) but did not distinguish HP as effectively from interstitial lung diseases (ILDs; sensitivity of 83% and specificity of 68%).Conclusions: Using a questionnaire may help clinicians identify potentially relevant exposures when evaluating a patient with newly identified ILD for HP. Serum IgG testing may also lead to identification of potentially relevant exposures, but its usefulness for distinguishing HP from other types of ILD is poor.

Antigen avoidance in people with hypersensitivity pneumonitis: A scoping review

BACKGROUND

Antigen avoidance (AA) is essential for people with hypersensitivity pneumonitis (HP). An intervention programme to promote continuous AA in people with HP will be the focus of future research.

OBJECTIVES

We systematically analysed the AA behaviour of people with HP, interventions of health-care providers to promote AA behaviour, clinical outcomes after AA, and evaluation methods after AA.

METHODS

We conducted a scoping review using six online databases and manual searches. Papers written in English or Japanese that reported cases on AA were selected. The extracted data were classified qualitatively.

RESULTS

In total 205 cases included in 109 eligible papers were examined.

CONCLUSIONS

This review clarified the fundamental evidence of AA in people with HP. These people required the continuous support of health-care providers to continue appropriate AA. This review highlighted four aspects that require further research to design interventions for promoting effective and continuous AA in people with HP.

Assessment and Management of Occupational Hypersensitivity Pneumonitis

The diagnosis and treatment of occupational hypersensitivity pneumonitis (OHP) remain complex and challenging in the absence of diagnostic gold standards or clinical guidelines. This review provides an update of the recent literature regarding the different presentations of OHP and the diagnostic yield and value of the diagnostic tests currently available, which include occupational and medical history, laboratory tests (serum-specific immunoglobulins, environmental sampling), imaging, bronchoalveolar lavage, transbronchial biopsy, transbronchial cryobiopsy, surgical lung biopsy, and specific inhalation challenges. These tools provide a precise differential diagnosis within the framework of interstitial lung diseases. However, among the chronic fibrotic forms, distinguishing OHP from sarcoidosis, nonspecific interstitial pneumonia and idiopathic pulmonary fibrosis remains a diagnostic challenge. Avoidance of exposure is pivotal for OHP management, whereas corticosteroids are fundamental in the pharmacological approach to this disease. In addition, studies describing the long-term benefits of immunosuppressive and antifibrotic agents have increased the use of these treatments in OHP.

Exposure assessment in hypersensitivity pneumonitis: a comprehensive review and proposed screening questionnaire

Hypersensitivity pneumonitis is an immune-mediated inflammatory lung disease characterised by the inhalation of environmental antigens leading to acute and chronic lung injury. Along with suggestive clinical and radiological findings, history and timing of suspected antigen exposure are important elements for diagnostic confidence. Unfortunately, many diagnoses remain tentative and based on vague and imprecise environmental or material exposure histories. To date, there has not been a comprehensive report highlighting the frequency and type of environmental exposure that might lead to or support a more systematic approach to antigen identification. We performed a comprehensive literature review to identify and classify causative antigens and their associated environmental contexts or source materials, with emphasis on the extent of the supportive literature for each exposure type. Eligible publications were those that reported unique inciting antigens and their respective environments or contexts. A clinical questionnaire was then proposed based on this review to better support diagnosis of hypersensitivity pneumonitis when antigen testing or other clinical and radiological variables are inconclusive or incomplete.

A Pathophysiological Perspective on COVID-19's Lethal Complication: From Viremia to Hypersensitivity Pneumonitis-like Immune Dysregulation

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the coronavirus responsible for our recent coronavirus disease 2019 pandemic, is driving a lung immunopathology that strongly resembles a severe form of hypersensitivity pneumonitis (HP). A review of recent Severe acute respiratory syndrome-related coronavirus (SARS-CoV) and SARS-CoV-2 medical reports, as well as described characteristics of HP, lead us to postulate a theory for SARS-CoV-2 severe disease. We propose that the novel SARS-CoV-2 can act as a trigger and substrate of an HP-like severe immune reaction especially in genetically vulnerable individuals in addition to those with immune senescence and dysregulation. Accordingly, the purpose of our letter is to shift the emphasis of concern surrounding immune activity from viral infection to an HP-like severe immune reaction. We review similarities in disease presentation between infection and allergy, relevant immunopathology, and outline phases of SARS-CoV-2 disease with perspectives on therapy and critical care. Altogether, the favored course is to begin treatments that address the disease at the earliest phase before immune dysregulation leading to uncontrolled pulmonary inflammation.

Hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a complex syndrome caused by the inhalation of a variety of antigens in susceptible and sensitized individuals. These antigens are found in the environment, mostly derived from bird proteins and fungi. The prevalence and incidence of HP vary widely depending on the intensity of exposure, the geographical area and the local climate. Immunopathologically, HP is characterized by an exaggerated humoral and cellular immune response affecting the small airways and lung parenchyma. A complex interplay of genetic, host and environmental factors underlies the development and progression of HP. HP can be classified into acute, chronic non-fibrotic and chronic fibrotic forms. Acute HP results from intermittent, high-level exposure to the inducing antigen, usually within a few hours of exposure, whereas chronic HP mostly originates from long-term, low-level exposure (usually to birds or moulds in the home), is not easy to define in terms of time, and may occur within weeks, months or even years of exposure. Some patients with fibrotic HP may evolve to a progressive phenotype, even with complete exposure avoidance. Diagnosis is based on an accurate exposure history, clinical presentation, characteristic high-resolution CT findings, specific IgG antibodies to the offending antigen, bronchoalveolar lavage and pathological features. Complete antigen avoidance is the mainstay of treatment. The pharmacotherapy of chronic HP consists of immunosuppressive drugs such as corticosteroids, with antifibrotic therapy being a potential therapy for patients with progressive disease.

Hypersensitivity pneumonitis of a bagpipe player: Fungal antigens as trigger?

Here we present a 79-year old man with chronic hypersensitivity pneumonitis probably caused by fungal contamination of a bagpipe. Several samples were taken from the patient's bagpipe. Four potential fungal antigens (Exophiala phaeomuriformis, Kwoniella europaea, Pyrenochaeta unguis-hominis and Aureobasidium melanogenum) as potential trigger of hypersensitivity pneumonitis were identified. A serum ELISA test with Exophiala phaeomuriformis indicated reactivity. Cessation of playing the bagpipe and application of glucocorticoids lead to an improvement of the patient's symptoms.

A Nonsmoker Man in His 40s With a Diagnosis of Genetic-Related Idiopathic Pulmonary Fibrosis (Surfactant-Protein C Gene Mutation)

A nonsmoker man in his 40s underwent bilateral lung transplantation with a referral diagnosis of genetic-related idiopathic pulmonary fibrosis (IPF). The patient had no medical history in childhood and early adulthood, nor was there a family history of IPF. His nonsmoker father presented with lung cancer at 59 years of age. The patient was a professional brass instrument player; he had started playing at 9 years of age, and he was recently playing 3 to 4 h per day. He had a 7-year clinical history of chronic cough and shortness of breath. Bilateral fine crackles were present at clinical examination. There was no digital clubbing. Data had been collected since 2015: no clinical or immunologic signs of connective tissue disease were evident, including autoantibodies for myositis or anti-synthetase syndrome. Chest radiograph showed diffuse interstitial lung disease. Results of pulmonary function tests yielded a restrictive pattern with decreased FVC and decreased total lung capacity (69% and 47% of predicted, respectively). The FEV₁/FVC ratio was 86%, and carbon monoxide transfer coefficient was 36% of predicted. BAL cellular analysis consisted of macrophages (66%), lymphocytes (19%; CD4⁺/CD8⁺ ratio, 0.16), neutrophils (10%), and eosinophils (5%).

Hypersensitivity pneumonitis: A new strategy for serodiagnosis and environmental surveys

We propose a strategy for serodiagnosis of hypersensitivity pneumonitis (HP): 1) question patients about their private or occupational activity, or visit him on site; 2) select panels of six somatic specific antigens appropriate for each type of exposure; 3) and use ELISA to test concomitantly two recombinant antigens highly specific to Farmer's lung, Metalworking-fluid HP, and for Bird fancier's lung. The serodiagnosis provides an immunological argument that may complete radiological, functional lung exploration and clinical features; 4) If the serodiagnosis is negative but the suspicion of HP is strong, a microbial analysis of the patient's specific exposure is conducted; 5) "A la carte" antigens are produced from the microorganisms isolated in the patient's environment sample and tested; 6) Finally, the patient may be asked to undergo a specific inhalation challenge with the offending antigens in a safety cabin, or to avoid his usual environment for a few days.

Rare Persistent Corneal Infection by Phoma sp. - A Case Report

We report a case of severe Phoma sp. corneal infection in a middle-aged, otherwise healthy, female patient who was using a soft contact lens. This is the first time that such an infection has been reported in Greece. Our case demonstrates the clinical difficulties and management challenges presented by these recalcitrant corneal infections. Management steps included corneal grafting, vitrectomy, and intravitreal antibiotics.

Fungal contamination of wind instruments: Immunological and clinical consequences for musicians

INTRODUCTION

Playing a wind instrument is an increasingly reported cause of hypersensitivity pneumonitis. However, current knowledge about contamination of wind instruments by fungi and specific fungal sensitization is scarce. Therefore, we aimed: (i) to assess the current prevalence and type of fungal contamination of wind instruments, (ii) to identify potential risk factors associated with instrument contamination, and (iii) to evaluate the prevalence of sensitization to these fungi among musicians.

MATERIAL AND METHODS

Musicians from music schools in eastern France and who played a wind instrument were prospectively recruited (NCT01487850). The mouthpiece and the reed of their instrument were sampled to quantify the magnitude and type of fungi. Each subject had a physical examination, a mycological analysis of saliva and a blood sample in search of serum precipitins against the most frequent fungi isolated from instruments. The results were compared with those of 40 healthy non-exposed controls.

RESULTS

Forty musicians playing a wind instrument (bassoon, clarinet, oboe, saxophone) were included. (i) 95% of wind instruments were colonized by fungi, mainly with Phoma spp., Penicillium spp. and Rhodotorula mucilaginosa; (ii) absence of systematic drying of the instrument was a main contributing factor; (iii) serum precipitins were significantly more present in the musicians' sera than in control sera and were consistent with the fungi present in their instrument.

CONCLUSION

This study reveals a constant and specific fungal contamination among wind reed instruments with a significant sensitization among musicians, pleading in favour of regular instrument cleaning. Physicians should be aware of this possible source of antigenic exposure.

Hypersensitivity pneumonitis: Antigen diversity and disease implications

Hypersensitivity pneumonitis (HP) is an immune-mediated syndrome triggered by inhalation of a wide variety of allergens, to which an individual has previously been sensitized. More than 200 agents responsible for the disease have already been identified; however, HP occurs only in a small number of individuals exposed to causal antigens. The present report provides an overview of the role of antigen role in HP, highlighting its diversity, research methods, and prevention strategies, as well as the impact on disease prognosis following elimination of antigen. HP is an underdiagnosed disease and, therefore, it is difficult to accurately estimate its incidence. Triggering antigens can be divided into six broad categories: bacteria, fungi, mycobacteria, animal and plant proteins, chemicals, and metals, represented by disease prototypes. The identification of causal antigen is a major challenge; it is impossible to obtain in about 30-60% of cases. The acute form of HP, with early detection and immediate eviction of causal antigen, tends to have an excellent prognosis. In the chronic form, partial recovery of disease is still possible; however, some cases tend to progress to fibrosis, even after removal from exposure. In conclusion, HP diagnosis should be based on a proactive search for potential antigen sources, although their identification is hampered by the lack of standardized methods of demonstrating the specific antigen sensitization. Antigen avoidance is a critical determinant in disease prognosis.

Musical Instrument-Associated Health Issues and Their Management

Playing musical instruments can bring joy to people, but can also cause a wide variety of health issues that range from mild disorders to potentially fatal conditions. Although sports medicine is an established medical subspecialty, relatively few studies have investigated the health issues associated with musical instruments. Here we present an overview of these health issues. These include infections due to microorganisms, allergic reactions, as well as mechanical injuries from sustained high pressures within the oral, mediastinal, thoracic, and abdominal cavities. For example, wind instruments can potentially harbor thousands of pathogenic organisms. If several players share the same instrument, these instruments present potential hazards in the spread of infections. A fatal case of hypersensitivity pneumonitis in a bagpiper is particularly noteworthy. Similarly, a case of gastrointestinal anthrax in an animal-hide drummer is a reminder of this rare but highly fatal disease. Although not fatal, hearing-related disorders, neuromuscular issues, musculoskeletal problems, and contact dermatitis are also very common among instrumentalists. This review aims to illuminate these under-recognized health issues by highlighting both the common conditions and the rare but fatal cases.

Hypersensitivity pneumonitis due to unclean continuous positive airway pressure equipment

Hypersensitivity pneumonitis is a potentially fatal immunological lung disease caused by occupational or environmental exposure to specific antigens. Here, we report on an obstructive sleep apnea patient whose hypersensitivity pneumonitis was aggravated because of the use of unclean continuous positive airway pressure equipment. This report shows that careful history taking is important when diagnosing hypersensitivity pneumonitis. Sleep specialists should be aware of the risks related to unclean continuous positive airway pressure equipment use, and obstructive sleep apnea patients should be instructed and monitored in the regular cleaning of their equipment.

Hypersensitivity pneumonitis among wind musicians - an overlooked disease?

Hypersensitivity pneumonitis (HP) is a complex pulmonary disorder mediated by the immune system and caused by various inhaled antigens against which the subject has previously been sensitized. In about 50% of the cases, the antigen is not identified. Identification and removal of the eliciting antigen is important for the prognosis.

We report two cases of HP caused by molds and atypical mycobacteria isolated from wind instruments. We present the first case of HP caused by bassoon playing and another case of HP caused by molds in a trombone. HP caused by fungi and bacteria in wind instruments may be much more common than previously thought.

HP caused by fungi and bacteria in wind instruments is probably underdiagnosed; this calls for more clinical attention when HP is suspected.

Occupational Health and the Performing Arts: An Introduction

OBJECTIVE

Workplace hazards in the performing arts cause injuries, disabilities, and deaths every year. Occupational health professionals are familiar with most of these hazards and are particularly qualified to contribute to efforts to reduce them. This article reviews current health issues in the performing arts and highlights opportunities for occupational health contributions.

METHODS

Recognized experts in performing arts medicine were consulted and articles illustrating performing arts health issues were reviewed. Literature sources included medical databases, unindexed art-health publications, and popular press articles.

RESULTS

Resources discussing hazards and health issues in theater, dance, voice, and instrumental musicians were located and reviewed.

CONCLUSIONS

Treatment providers have a history of involvement with segments of the performing arts. The occupational health approach to workplace health issues can effectively complement these efforts. Sources of further information on performing arts health concerns are available.

Hypersensitivity pneumonitis: a complex lung disease

Hypersensitivity pneumonitis (HP), also called extrinsic allergic alveolitis, is a respiratory syndrome involving the lung parenchyma and specifically the alveoli, terminal bronchioli, and alveolar interstitium, due to a delayed allergic reaction. Such reaction is secondary to a repeated and prolonged inhalation of different types of organic dusts or other substances to which the patient is sensitized and hyper responsive, primarily consisting of organic dusts of animal or vegetable origin, more rarely from chemicals. The prevalence of HP is difficult to evaluate because of uncertainties in detection and misdiagnosis and lacking of widely accepted diagnostic criteria, and varies considerably depending on disease definition, diagnostic methods, exposure modalities, geographical conditions, agricultural and industrial practices, and host risk factors. HP can be caused by multiple agents that are present in work places and in the home, such as microbes, animal and plant proteins, organic and inorganic chemicals. The number of environment, settings and causative agents is increasing over time. From the clinical point of view HP can be divided in acute/subacute and chronic, depending on the intensity and frequency of exposure to causative antigens. The mainstay in managing HP is the avoidance of the causative antigen, though the complete removal is not always possible due to the difficulties to identify the agent or because its avoidance may lead to major changes in life style or occupational settings. HP is a complex syndrome that needs urgently for more stringent and selective diagnostic criteria and validation, including wider panels of IgG, and a closer collaboration with occupational physicians, as part of a multidisciplinary expertise.

First case of chromoblastomycosis due to Phoma insulana

Chromoblastomycosis is a chronic infection, caused by pigmented fungi affecting skin and subcutaneous tissues characterized by verrucous nodules or plaques. Fonsecaea pedrosoi and Cladophialophora carrionii are the prevalent agents in the endemic areas. Phoma is an uncommon agent of human infection and involved mainly with phaeohyphomycosis cases. The case of a patient with a history of laceration in foot followed by verrucous aspect and scaly lesions, which had evolved for 27 years is presented. On physical examination disease was clinically compatible with chromoblastomycosis and the microscopic examination of scales showed fumagoid cells. On culture a dematiaceous fungus was grown. The agent was confirmed to be Phoma insulana based on its morphology and PCR-sequencing. This fungal agent has not been previously reported in association with this pathology.

Chronic hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HSP) is a common interstitial lung disease resulting from inhalation of a large variety of antigens by susceptible individuals. The disease is best classified as acute and chronic. Chronic HSP can be fibrosing or not. Fibrotic HSP has a large differential diagnosis and has a worse prognosis. The most common etiologies for HSP are reviewed. Diagnostic criteria are proposed for both chronic forms based on exposure, lung auscultation, lung function tests, HRCT findings, bronchoalveolar lavage, and biopsies. Treatment options are limited, but lung transplantation results in greater survival in comparison to idiopathic pulmonary fibrosis. Randomized trials with new antifibrotic agents are necessary.

Chronic hypersensitivity pneumonitis: important considerations in the work-up of this fibrotic lung disease

PURPOSE OF REVIEW

Chronic hypersensitivity pneumonitis is increasingly recognized as an important mimic of other fibrotic lung diseases. This review will summarize recent data regarding the importance and difficulty of determining causative exposures both for accurate diagnosis and prognosis, and describe the expanded pathologic spectrum of the disease, the effects of fibrosis on prognosis and challenges in the diagnostic evaluation.

RECENT FINDINGS

Several recent publications show the potential pathologic patterns induced by chronic hypersensitivity pneumonitis are broader than the classic triad of bronchiolitis, interstitial infiltrates and granulomas. Other pathologic patterns include nonspecific interstitial pneumonia, usual interstitial pneumonia, organizing pneumonia, bronchiolitis and airway centric fibrosis. Detecting a causative antigen in fibrotic hypersensitivity pneumonitis is challenging but critically important both for accurate diagnosis and improved prognosis. The prognosis in hypersensitivity pneumonitis worsens in the presence of fibrosis, but it remains significantly better than idiopathic pulmonary fibrosis.

SUMMARY

Hypersensitivity pneumonitis is increasingly recognized as an important cause of fibrotic interstitial lung disease. Hypersensitivity pneumonitis demonstrates a remarkable tendency to mimic other idiopathic interstitial pneumonias. A detailed exposure history remains a cornerstone of diagnosis and management.

Fatal Hypersensitivity Pneumonitis from Exposure to Fusarium vasinfectum in a Home Environment: A Case Report

BACKGROUND

Hypersensitivity pneumonitis (HP) is a rare, non-IgE-mediated inflammatory lung disease caused by inhalational exposure to various antigens found in occupational, avocational and home environments. The prognosis is favorable with early detection and prompt removal of the causative agent, and fatalities are unusual. We present a fatal case of HP caused by chronic exposure to Fusarium vasinfectum mold in the home.

CASE REPORT

A 37-year-old white male presented with a 6-month history of progressively worsening dyspnea, cough, weight loss and fatigue associated with the self-renovation of his water-damaged, mold-infested mobile home. Evaluation included a physical examination (hypoxia, inspiratory crackles and expiratory rhonchi), baseline pulmonary function testing (mixed obstructive/restrictive pattern), chest computed tomography (bronchiectasis, fibrosis and diffuse interstitial involvement), bronchoalveolar lavage (macrophages 20%, lymphocytes 28% and neutrophils 52%) and transbronchial biopsy (interstitial fibrosis and chronic inflammatory infiltrate). Mold culture from the home grew out F. vasinfectum. An Ouchterlony double diffusion technique documented high antibody titer to F. vasinfectum. Despite aggressive intravenous corticosteroid treatment, the patient's lung function declined to the extent that he could not be removed from ventilator support following an open lung biopsy, eventually resulting in death.

CONCLUSION

This is the first reported case of fatal HP related to an acute exacerbation of a chronic form of HP following continuous and intense exposure to F. vasinfectum. Although uncommon, a high index of suspicion for HP is necessary in patients with progressive respiratory symptoms and known environmental antigen exposure. With early detection and prompt removal of the causative antigen, HP prognosis is generally favorable, but can progress to fatal disease with continued exposure.

Chronic hypersensitivity pneumonitis in patients diagnosed with idiopathic pulmonary fibrosis: a prospective case-cohort study

BACKGROUND

The clinical features of idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis can be indistinguishable; the need to eliminate occult environmental factors known to cause pulmonary fibrosis in patients suspected to have IPF during diagnostic evaluation is evident. We aimed to investigate occult, putative causes in the environments of patients diagnosed with IPF using tests beyond those conventionally used.

METHODS

In this case-cohort study, 60 consecutive patients diagnosed with IPF on the basis of the 2000 American Thoracic Society (ATS) and the European Respiratory Society (ERS) criteria were prospectively followed up every 4 months for 6 years between Jan 1, 2004, and Dec 31, 2009. At each visit a uniformly applied questionnaire was administered to these 60 patients to identify occult antigen exposure known to cause hypersensitivity pneumonitis. Patients underwent specific IgG determination, bronchoalveolar lavage, bronchial challenge testing with suspected antigens, and re-review of histopathological features in existing and subsequently obtained surgical lung biopsy samples and from lung explants. Specimens obtained from suspected sources from the patient's environment were subjected to cultures in microbiology laboratory. These clinical data and discussions among pulmonologists and radiologists familiar with IPF were used to confirm the diagnosis in accordance with 2011 ATS, ERS, Japanese Respiratory Society, and Latin American Thoracic Association guidelines; 46 of the 60 patients had IPF according to the 2011 guidelines, and our analyses in this study were focused on these 46 patients.

FINDINGS

20 of the 46 (43%, 95% CI 29-58) patients with IPF according to 2011 guidelines had a subsequent diagnosis of chronic hypersensitivity pneumonitis: nine patients had positive bronchial challenge testing (eight of whom were also IgG positive and six of these patients also had surgical lung biopsy showing a pattern consistent with chronic hypersensitivity pneumonitis); seven were IgG positive plus had histopathology on surgical lung biopsy that was consistent with hypersensitivity pneumonitis; one was IgG positive plus had greater than 20% lymphocytes in bronchoalveolar lavage fluid; and three had findings on surgical lung biopsy that were consistent with subacute hypersensitivity pneumonitis (and IgG positive). Altogether, 29 of 46 patients diagnosed with IPF who had met the 2011 criteria had lung tissue available for histopathology (surgical lung biopsy in 28 patients and explanted lung in two patients, one of whom also had surgical biopsy) during the study period, and 16 of the 20 patients with chronic hypersensitivity pneumonitis had histopathological features on surgical lung biopsy that were consistent with this diagnosis. 26 of the 46 patients remained with a diagnosis of IPF.

INTERPRETATION

Almost half of patients diagnosed with IPF on the basis of 2011 criteria were subsequently diagnosed with chronic hypersensitivity pneumonitis, and most of these cases were attributed to exposure of occult avian antigens from commonly used feather bedding. Our results reflect findings in one centre with recognised expertise in chronic hypersensitivity pneumonitis, and further research and studies at other centres are warranted.

FUNDING

Fondo de Investigaciones Sanitarias; Fundació Privada Cellex; SEPAR 2010.

The use of specific inhalation challenge in hypersensitivity pneumonitis

PURPOSE OF REVIEW

The diagnosis of hypersensitivity pneumonitis remains a dilemma because of the absence of any characteristic features able to distinguish it from other interstitial lung diseases. We analyze the current role of the specific inhalation challenge (SIC) in the diagnosis of this entity.

RECENT FINDINGS

Few descriptions of the use of SIC for the diagnosis of hypersensitivity pneumonitis have been published in recent years. In fact, hypersensitivity pneumonitis is still diagnosed on the basis of clinical criteria, as there is no agreement on the diagnostic utility of SIC. Two major reviews carried out in the past year have concluded that this test is not standardized and is usually unnecessary; however, a third study found that the test can indeed recreate the symptoms and functional abnormalities in the laboratory, and may therefore be of considerable use in the diagnosis of hypersensitivity pneumonitis.

SUMMARY

Hypersensitivity pneumonitis remains a diagnostic challenge. Given that the main cause of the disease is sensitization and hyper-responsiveness to specific antigens in susceptible individuals, SIC is an obvious candidate as the gold standard for diagnosis of this entity. The present review analyzes the reasons for the test's limited use, assesses its diagnostic utility, and proposes a basis for its standardization.

New occupational and environmental causes of asthma and extrinsic allergic alveolitis

Asthma and extrinsic allergic alveolitis (EAA) remain prevalent respiratory diseases and the cause of a significant disease burden. This article reviews the recent occupational and environmental causes described for these conditions. Even over the limited time spam addressed by this article, novel agents and new data relating to already suggested causes have been described. Various types of work tasks or exposures are described that appear to cause both asthma and EAA. Isocyanates, the best example of dual potential to cause asthma and EAA are discussed, as is the new understanding of the role metal-working fluids play when causing respiratory diseases.

Hypersensitivity pneumonitis

Clinical manifestations of hypersensitivity pneumonitis may closely mimic other interstitial lung diseases, and the disease onset is usually insidious. High-resolution computed tomography and bronchoalveolar lavage are the sensitive and characteristic diagnostic tests for hypersensitivity pneumonitis. The relevant antigen to hypersensitivity pneumonitis cannot be identified in up to 20% to 30% of patients. Clinicians should be aware that hypersensitivity pneumonitis must be considered in all cases of interstitial lung disease, and a detailed environmental exposure history is mandatory.

Indoor air contaminants and their impact on respiratory pathologies

Humans spend a considerable amount of their time breathing air inside enclosed spaces in which, due to various sources, there may be contaminants that deteriorate the air quality. This is an important risk factor for the health of the general population. This review evaluates the contaminants that are present in the air of indoor air spaces, describing the sources that generate them as well as the physiopathological mechanisms and the diseases that they may cause in the respiratory system.

Chronic hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a complex syndrome caused by the inhalation of environmental antigens. Chronic HP may mimic other fibrotic lung diseases, such as idiopathic pulmonary fibrosis. Recognition of the antigen is important for diagnosis; avoidance of further exposure is critical for treatment. Fibrosis on biopsy or high-resolution computed tomography is a predictor of increased mortality. Additional research is needed to understand why the disease develops only in a minority of exposed individuals and why cases of chronic HP may progress without further antigen exposure.