Hot tub lung: presenting features and clinical course of 21 patients

Disinfection and monitoring of Mycobacterium avium complex in the environment: A novel approach to the management of hot tub lung

A 45-year-old man visited our hospital with a chronic cough and breathing difficulties. Chest computed tomography revealed diffuse granular shadows. Mycobacterium avium (M. avium) was cultured from bronchoalveolar lavage fluid (BALF). Surgical lung biopsy revealed non-necrotizing granulomas, and M. avium-specific PCR was positive in the tissue. M. avium was also cultured in a sample from the inlet of the patient's bathtub. Mycobacterium avium tandem repeat variable-number tandem-repeat loci (MATR-VNTR) analysis confirmed that the M. avium cultured from BALF and the bathtub inlet had identical allele profiles. The patient's symptoms and oxygenation improved while the patient was in hospital, presumably because of lack of ongoing exposure to M. avium. He was diagnosed with hot tub lung. We advised the patient to avoid bathing to avoid re-exposure. However, the patient was unwilling to follow this advice. Therefore, his bathtub and pipework were disinfected by heating them to over 70 °C. We confirmed that the disinfection has been successful by repeated culture of environmental samples. Three months after resuming bathtub use, the patient's symptoms resolved, and the pulmonary shadows seen on the initial radiography did not recur. For the treatment of hot tub lung, disinfection of M. avium complex in the environment should be considered and the environment should be monitored to confirm eradication.

[Diagnosis and Treatment of Hypersensitivity Pneumonitis - S2k Guideline of the German Respiratory Society and the German Society for Allergology and Clinical Immunology]

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease (ILD) in sensitized individuals caused by a large variety of inhaled antigens. The clinical form of acute HP is often misdiagnosed, while the chronic form, especially the chronic fibrotic HP, is difficult to differentiate from other fibrotic ILDs. The present guideline for the diagnosis and treatment of HP replaces the former German recommendations for the diagnosis of HP from 2007 and is amended explicitly by the issue of the chronic fibrotic form, as well as by treatment recommendations for the first time. The evidence was discussed by a multidisciplinary committee of experts. Then, recommendations were formulated for twelve questions on important issues of diagnosis and treatment strategies. Recently published national and international guidelines for ILDs and HP were considered. Detailed background information on HP is useful for a deeper insight into HP and the handling of the guideline.

Chlorine-Induced Lung Injury From Hot Tub Exposure

Chlorine, a dense and irritating gas used in pool disinfection, can cause severe respiratory issues, including airway damage, alveolar injury, pulmonary edema, and chronic conditions such as bronchiolitis obliterans. This case study describes a patient initially thought to have hot tub lung (HTL) due to symptoms, hot tub use, and imaging findings. However, negative Mycobacterium tests and significant chlorine exposure led to a revised diagnosis of chlorine-induced lung injury. The diagnosis was further supported by the patient's clinical improvement and prior normal lung scans.

Effect of antigen removal in hypersensitivity pneumonitis

BACKGROUND

Antigen removal is a cornerstone of treatment of hypersensitivity pneumonitis (HP), but its association with transplant-free survival remains unclear. Further, HP guidelines conflict as to whether antigen removal is a recommended diagnostic test in patients with suspected HP.

OBJECTIVE

The purpose of this study is to (1) evaluate the impact of antigen removal on transplant-free survival and (2) to describe the impact of antigen removal on pulmonary function testing and imaging in a retrospective cohort of patients with HP.

METHODS

We retrospectively identified HP patients evaluated between 2011 and 2020. Demographic, physiologic, radiographic, and pathologic data were recorded.

RESULTS

212 patients were included in the cohort. Patients who identified and removed antigen had a better transplant-free survival than patients who did not identify antigen and patients who identified but did not remove antigen. Antigen removal was associated with improvement in FVC by 10% predicted in 16.9% of patients with fibrotic HP and 56.7% of patients with nonfibrotic HP.

DISCUSSION

Our results suggest that over 50% of nonfibrotic HP patients and 16.9% of fibrotic HP patients improve with exposure removal. In addition, antigen removal, rather than antigen identification, is associated with transplant-free survival in HP.

Growing from common ground: nontuberculous mycobacteria and bronchiectasis

Bronchiectasis and nontuberculous mycobacteria (NTM) are intricately intertwined, with NTM capable of being both a cause and consequence of bronchiectatic disease. This narrative review focuses on the common ground of bronchiectasis and NTM pulmonary disease (NTM-PD) in terms of diagnostic approach, underlying risk factors and treatment strategies. NTM-PD diagnosis relies on a combination of clinical, radiological and microbiological criteria. Although their epidemiology is complicated by detection and reporting biases, the prevalence and pathogenicity of NTM species vary geographically, with Mycobacterium avium complex and Mycobacterium abscessus subspecies most frequently isolated in bronchiectasis-associated NTM-PD. Diagnosis of nodular bronchiectatic NTM-PD should prompt investigation of host factors, including disorders of mucociliary clearance, connective tissue diseases and immunodeficiencies, either genetic or acquired. Treatment of NTM-PD in bronchiectasis involves a multidisciplinary approach and considers the (sub)species involved, disease severity and comorbidities. Current guideline-based antimicrobial treatment of NTM-PD is considered long, cumbersome and unsatisfying in terms of outcomes. Novel treatment regimens and strategies are being explored, including rifampicin-free regimens and inclusion of clofazimine and inhaled antibiotics. Host-directed therapies, such as immunomodulators and cytokine-based therapies, might enhance antimycobacterial immune responses. Optimising supportive care, as well as pathogen- and host-directed strategies, is crucial, highlighting the need for personalised approaches tailored to individual patient needs. Further research is warranted to elucidate the complex interplay between host and mycobacterial factors, informing more effective management strategies.

A case of hot tub lung secondary to mycobacterium avium complex in Victoria, Australia

Hot tub lung (HTL) is a type of Hypersensitivity Pneumonitis (HP) caused by inhalation of aerosols containing non-tuberculous mycobacteria (NTM). We report the first case of hot tub lung in Victoria, Australia. A 31-year-old female presented with 3 weeks of dyspnoea, fevers and malaise, despite a course of antibiotics. She had used an indoor spa frequently for the past several months. She was hypoxic saturating 86% on room air. Examination revealed fine bilateral basal crepitations without wheeze. Inflammatory markers were elevated. A high resolution CT (HRCT) chest demonstrated extensive bilateral ground glass changes and centrilobular nodular opacities involving upper and lower zones. Bronchial washings were obtained and isolated Mycobacterium Avium Complex. Clinically, the patient had excellent response to empirical corticosteroids and avoidance of hot tub. This case highlights the importance of clinical history taking and suspicion of Hot Tub Lung as a differential diagnosis in a patient with a compatible clinical history, radiology and microbiology and exposure to a hot tub.

Recurrent episodes of febrile dyspnoea: hypersensitivity pneumonitis caused by a household ultrasonic humidifier

Hypersensitivity pneumonitis is an immune-mediated interstitial lung disease that presents with respiratory symptoms, with or without systemic symptoms, following exposure to an identified or unidentified external factor. It can be caused by extrinsic factors including household items such as ultrasonic humidifiers.We present an intriguing case of a previously healthy 50-year-old man who displayed recurrent episodes of progressive dyspnoea and fever after repeated exposure to his household ultrasonic humidifier. He was treated with corticosteroids, followed by the removal of the humidifier, resulting in total recovery and absence of recurrence of further episodes.The clinical presentation of hypersensitivity pneumonitis can be dramatic, and the differential diagnosis is broad. The correct diagnosis is achieved by combining clinical, radiological and histopathological patterns. The key to finding the aetiology lies in a thorough history, with an important role for household investigations to identify the external factor.

Differential diagnosis of pulmonary sarcoidosis: a review

Diagnosing pulmonary sarcoidosis raises challenges due to both the absence of a specific diagnostic criterion and the varied presentations capable of mimicking many other conditions. The aim of this review is to help non-sarcoidosis experts establish optimal differential-diagnosis strategies tailored to each situation. Alternative granulomatous diseases that must be ruled out include infections (notably tuberculosis, nontuberculous mycobacterial infections, and histoplasmosis), chronic beryllium disease, hypersensitivity pneumonitis, granulomatous talcosis, drug-induced granulomatosis (notably due to TNF-a antagonists, immune checkpoint inhibitors, targeted therapies, and interferons), immune deficiencies, genetic disorders (Blau syndrome), Crohn's disease, granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and malignancy-associated granulomatosis. Ruling out lymphoproliferative disorders may also be very challenging before obtaining typical biopsy specimen. The first step is an assessment of epidemiological factors, notably the incidence of sarcoidosis and of alternative diagnoses; exposure to risk factors (e.g., infectious, occupational, and environmental agents); and exposure to drugs taken for therapeutic or recreational purposes. The clinical history, physical examination and, above all, chest computed tomography indicate which differential diagnoses are most likely, thereby guiding the choice of subsequent investigations (e.g., microbiological investigations, lymphocyte proliferation tests with metals, autoantibody assays, and genetic tests). The goal is to rule out all diagnoses other than sarcoidosis that are consistent with the clinical situation. Chest computed tomography findings, from common to rare and from typical to atypical, are described for sarcoidosis and the alternatives. The pathology of granulomas and associated lesions is discussed and diagnostically helpful stains specified. In some patients, the definite diagnosis may require the continuous gathering of information during follow-up. Diseases that often closely mimic sarcoidosis include chronic beryllium disease and drug-induced granulomatosis. Tuberculosis rarely resembles sarcoidosis but is a leading differential diagnosis in regions of high tuberculosis endemicity.

Impact of diagnostic guidelines on the diagnosis of hypersensitivity pneumonitis

Introduction

Hypersensitivity pneumonitis (HP) is an immune-mediated interstitial lung disease from exposure to environmental antigens. Diagnosing HP could be challenging. The American College of Chest Physicians (CHEST) and American Thoracic Society/Japanese Respiratory Society/and Asociación Latinoamericana del Tórax (ATS/JRS/ALAT) have published diagnostic guidelines in 2021 and 2020 respectively. The CHEST guideline uses four grades of confidence: confident (>90%), provisional high (70-89%), provisional low (51-69%), and unlikely (≤50%). The ATS/JRS/ALAT guideline uses five grades of confidence: definite (>90%), high (80-89%), moderate (70-79%), low (51-69%) and not excluded (≤50%). In this study, we determined how these two guidelines could have affected the diagnosis of HP made before the guidelines.

Methods

Two hundred and fifty-nine adult patients from a previous cohort with HP (ICD-9:495) made between Jan. 1, 2008, and Dec. 31, 2013, at Duke University Medical Center were included. We simplified the diagnostic confidence into three categories so we could compare the guidelines: high (≥90%), intermediate (51-89%), and low (≤50%).

Results

There were 156 female and 103 male. Mean age was 58 (range: 20-90). 68.8% of the patients had restrictive defects (FVC < 80% pred) and 48.6% had lung biopsy. The CHEST guideline classified 33.6% of the patients into high, 59.5% into intermediate and 6.9% into low confidence categories. The ATS/JRS/ALAT guideline classified 29.7% of the patients into high, 21.2% into intermediate and 49.0% into low confidence categories (p < 0.0001 vs. CHEST). Cohen's kappa was 0.331. In patients with identifiable inciting agents (IAs) (N = 168), the CHEST guideline classified 32.1% of the patients into high, 64.3% into intermediate and 3.6% into low confidence categories. The ATS/JRS/ALAT guideline classified 29.2% of the patients into high, 20.8% into intermediate, and 50.0% into low confidence categories. Cohen's kappa was 0.314.

Discussion

In our HP cohort with two-thirds of the patients with restrictive defects, we found the two guidelines had fair agreement in diagnosing HP with or without identifiable IAs. They agreed more when the diagnostic confidence was high. When the diagnostic confidence was lower, however, the ATS/JRS/ALAT guideline was more stringent. Clinicians should be aware of the differences between the two guidelines when evaluating patients suspicious of HP.

High-Resolution Computed Tomography of Nonfibrotic Interstitial Lung Disease

Nonfibrotic interstitial lung diseases include a heterogeneous group of conditions that can result in various patterns of lung involvement. When approaching the computed tomographic (CT) scan of a patient with a suspected or known interstitial lung disease, the use of the appropriate radiological terms and a systematic, structured approach to the interpretation of the imaging findings are essential to reach a confident diagnosis or to limit the list of differentials to few possibilities. The large number of conditions that cause nonfibrotic interstitial lung diseases prevents a thorough discussion of all these entities. Therefore, this article will focus on the most common chronic lung diseases that can cause these CT findings. A pattern-based approach is used, with a discussion of nodular pattern, consolidation, crazy paving, ground-glass opacities, septal thickening, and calcifications. The different clinical conditions will be described based on their predominant pattern, with particular attention to findings that can help in the differential diagnosis.

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.

Antigen avoidance and outcome of nonfibrotic and fibrotic hypersensitivity pneumonitis

Background

Hypersensitivity pneumonitis (HP) is classified into nonfibrotic and fibrotic phenotypes. Patients with nonfibrotic HP often experience recurrence and develop fibrosis, whereas those with fibrotic HP have a poor prognosis. Although antigen avoidance has long been the first line of treatment for HP, its impact on prognosis has been poorly reported.

Methods

Medical records of 121 patients with HP diagnosed by new diagnostic criteria of American Thoracic Society/Japanese Respiratory Society/Asociación Latinoamericana del Tórax (ATS/JRS/ALAT) guidelines and treated at our institution in Saitama, Japan, were retrospectively analysed. HP was classified into nonfibrotic and fibrotic phenotypes and six HP subtypes: summer-type, bird-related, home-related and occupational HP, humidifier lung, and hot tub lung. Achievement of reduced exposure to inciting agents was divided into complete antigen avoidance (CAA) and incomplete antigen avoidance (IAA) by HP subtype.

Results

Of the 74 patients with nonfibrotic HP, 30 achieved CAA and experienced no recurrence or development of fibrosis. In the remaining 44 patients with IAA, 24 (54.5%) experienced recurrence and/or development of fibrosis. The all-cause 5-year mortality rate in the 47 patients with fibrotic HP was 47.8%. Negative prognostic factors of HP-related mortality in these patients were <50% lymphocytes in bronchoalveolar lavage (BAL) and honeycombing. Multivariate analysis showed a tendency for IAA to be related to poorer survival (hazard ratio 3.452, 95% CI 0.964–12.359, p=0.057).

Conclusions

In the patients with nonfibrotic HP, CAA resulted in no recurrence or development of fibrosis and longer survival. In the patients with fibrotic HP, <50% lymphocytes in BAL and honeycombing were negative prognostic factors for mortality.

Complete antigen avoidance reduces the recurrence and development of fibrosis in patients with nonfibrotic HP and may be related to longer survival in patients with fibrotic HPhttps://bit.ly/3E5EVLR

Varying clinical presentations of nontuberculous mycobacterial disease : Similar to but different from tuberculosis

The incidence rate of pulmonary nontuberculous mycobacterial disease (PNTMD) in Japan is the highest among major industrialized nations. Although the typical clinical course and radiological manifestations of PNTMD are different from those of pulmonary tuberculosis (TB), confusion about these mycobacterial diseases leads to a diagnostic pitfall. Diagnostic challenges include the coexistence of Mycobacterium tuberculosis (MTB) and nontuberculous mycobacteria (NTM), false positives for NTM in MTB nucleic acid amplification tests, microbial substitution, and abnormal radiological manifestations caused by NTM. Features of extrapulmonary NTM diseases, such as pleurisy, vertebral osteomyelitis, and disseminated disease, are different from the corresponding tuberculous diseases. Moreover, the immunological background of the patient (status of human immunodeficiency virus infection with or without antiviral therapy, continuation or discontinuation of immunosuppressive therapy, use of immune checkpoint inhibitor, pregnancy and delivery, etc.) influences the pathophysiology of mycobacterial diseases. This review describes the varying clinical presentations of NTM disease with emphasis on the differences from TB. J. Med. Invest. 68 : 220-227, August, 2021.

Management of Fibrotic Hypersensitivity Pneumonitis

Fibrotic hypersensitivity pneumonitis (fHP) is a chronic, often progressive fibrosing form of interstitial lung disease caused by inhaled antigenic exposures. fHP can lead to impaired respiratory function, reduced disease-related quality of life, and early mortality. Management of fHP should start with exposure remediation where possible, with systemic immunosuppression and antifibrotic therapy considered in patients with symptomatic or progressive disease. Nonpharmacologic and supportive management should be offered and, in cases of treatment-resistant, progressive illness, lung transplant should be considered.

Transbronchial biopsy in chronic hypersensitivity pneumonitis

Introduction

The diagnosis of chronic hypersensitivity pneumonitis (CHP) is based on relevant exposure, tomographic findings and, in some cases, pathological data. The role of bronchoscopy is uncertain, especially in the fibrotic form of CHP.

Aim

To analyze the yield of transbronchial biopsy (TBBx) in patients with CHP according to tomographic findings and to evaluate the importance of bronchoalveolar lavage (BAL) in the diagnostic approach.

Methods

This retrospective study analyzed patients with CHP who underwent TBBx in São Paulo, Brazil. The TBBx findings were classified as characteristic (granulomas and/or multinucleated giant cells, associated or not with peribronchiolar infiltration of lymphocytes and plasma cells and bronchiolocentric distribution) and supportive (data indicative of small airway injury: peribronchiolar metaplasia, organizing pneumonia, and intra-alveolar foamy macrophages).

Results

One hundred nine patients were included. The presence of characteristic findings of HP was seen in 16 patients (14.7%), and supportive findings were seen in 32 patients (29.4%), with a total yield of 44%. Pathological characteristic findings were more common in cases without fibrosis on high-resolution computed tomography (HRCT) (27.3% vs. 9.2%, p= 0.014), whereas the presence of supportive findings was more common in fibrotic HP (38.1% vs. 9.1%, p= 0.002). Fifty-two patients had differential cytology in BAL fluid. Lymphocytosis (> 20%) was present in 51.9% of the patients. There was no difference in the median lymphocyte count according to nonfibrotic and fibrotic tomographic findings on HRCT.

Conclusion

TBBx and BAL fluid cytology have a role in CHP diagnosis.

Approach to the diagnosis and treatment of non-tuberculous mycobacterial disease

Non-tuberculous mycobacteria (NTM) is a collective name given to a group of more than 190 species of Mycobacterium. The clinical presentation for most NTM infections is non-specific, often resulting in delayed diagnosis. Further complicating matters is that NTM organisms can be difficult to isolate. Medications used to treat NTM infection can be difficult for patients to tolerate, and prolonged courses of anti-mycobacterial therapy are often required for adequate suppression or eradication. Herein, we review different NTM syndromes, appropriate diagnostic tests, and treatment regimens.

Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report

BACKGROUND

The purpose of this analysis is to provide evidence-based and consensus-derived guidance for clinicians to improve individual diagnostic decision-making for hypersensitivity pneumonitis (HP) and decrease diagnostic practice variability.

STUDY DESIGN AND METHODS

Approved panelists developed key questions regarding the diagnosis of HP using the PICO (Population, Intervention, Comparator, Outcome) format. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion, and vetted evaluation tools were used to assess the quality of included studies, to extract data, and to grade the level of evidence supporting each recommendation or statement. The quality of the evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Graded recommendations and ungraded consensus-based statements were drafted and voted on using a modified Delphi technique to achieve consensus. A diagnostic algorithm is provided, using supporting data from the recommendations where possible, along with expert consensus to help physicians gauge the probability of HP.

RESULTS

The systematic review of the literature based on 14 PICO questions resulted in 14 key action statements: 12 evidence-based, graded recommendations and 2 ungraded consensus-based statements. All evidence was of very low quality.

INTERPRETATION

Diagnosis of HP should employ a patient-centered approach and include a multidisciplinary assessment that incorporates the environmental and occupational exposure history and CT pattern to establish diagnostic confidence prior to considering BAL and/or lung biopsy. Criteria are presented to facilitate diagnosis of HP. Additional research is needed on the performance characteristics and generalizability of exposure assessment tools and traditional and new diagnostic tests in modifying clinical decision-making for HP, particularly among those with a provisional diagnosis.

Executive Summary: Diagnosis and Evaluation of Hypersensitivity Pneumonitis: CHEST Guideline and Expert Panel Report

BACKGROUND

The purpose of this summary is to provide a synopsis of evidence-based and consensus-derived guidance for clinicians to improve individual diagnostic decision-making for hypersensitivity pneumonitis (HP) and decrease diagnostic practice variability.

STUDY DESIGN AND METHODS

Approved panelists developed key questions regarding the diagnosis of HP using the PICO (Population, Intervention, Comparator, and Outcome) format. MEDLINE (via PubMed) and the Cochrane Library were systematically searched for relevant literature, which was supplemented by manual searches. References were screened for inclusion and vetted evaluation tools were used to assess the quality of included studies, to extract data, and to grade the level of evidence supporting each recommendation or statement. The quality of the evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Graded recommendations and ungraded consensus-based statements were drafted and voted on using a modified Delphi technique to achieve consensus.

RESULTS

The systematic review of the literature based on 14 PICO questions resulted in 14 key action statements: 12 evidence-based, graded recommendations, and 2 ungraded consensus-based statements. All evidence was of very low quality.

INTERPRETATION

Diagnosis of HP should employ a patient-centered approach and include a multidisciplinary assessment that incorporates the environmental and occupational exposure history and CT pattern to establish diagnostic confidence prior to considering BAL and/or lung biopsy. Additional research is needed on the performance characteristics and generalizability of exposure assessment tools and traditional and new diagnostic tests in modifying clinical decision-making for HP, particularly among those with a provisional 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.

[Hot tub lung: A retrospective analysis of 14 cases]

INTRODUCTION

Hot tub lung (HTL) is a hypersensitivity pneumonitis (HP) related to inhalation of non-tuberculous mycobacteria (NTM) when exposed to ejected jet droplets from a jacuzzi. The aetiological debate is not completely settled in the literature.

METHOD

An observational study of 14 cases of HTL, diagnosed at the University Hospital of Besançon, France, between 2004 and 2018 according to the diagnostic criteria used in the clinic.

RESULTS

This cohort corresponds to type I HP (inflammatory), with one case of type II HP. Decrease of lung transfer for carbon monoxide was present in 86% of examinations (n=12/14). In total, 84% of bronchoalveolar lavages showed a lymphocytic cellular pattern≥30% (n=11/13). The environmental survey enabled the identification of NTM in 93% of cases (n=13/14), mainly Mycobacterium avium. Serum precipitins directed against NTM were found in 10% of the cases (n=2/20). Three cases received corticosteroid therapy and none received antibiotics. Antigenic eviction has improved the symptomatology in all cases.

CONCLUSIONS

Our cohort supports the hypothesis that HTL is predominantly a type I HP. Avoidance of the agent involved (NTM) is necessary. The diagnosis is difficult because serum precipitins against NTM are not easily demonstrable. An environmental survey could facilitate the identification of the NTM. Prevention of HTL depends on education of the clinician and the patient.

Exposure Assessment Tools for Hypersensitivity Pneumonitis. An Official American Thoracic Society Workshop Report

This report is based on proceedings from the Exposure Assessment Tools for Hypersensitivity Pneumonitis (HP) Workshop, sponsored by the American Thoracic Society, that took place on May 18, 2019, in Dallas, Texas. The workshop was initiated by members from the Environmental, Occupational, and Population Health and Clinical Problems Assemblies of the American Thoracic Society. Participants included international experts from pulmonary medicine, occupational medicine, radiology, pathology, and exposure science. The meeting objectives were to 1) define currently available tools for exposure assessment in evaluation of HP, 2) describe the evidence base supporting the role for these exposure assessment tools in HP evaluation, 3) identify limitations and barriers to each tool's implementation in clinical practice, 4) determine which exposure assessment tools demonstrate the best performance characteristics and applicability, and 5) identify research needs for improving exposure assessment tools for HP. Specific discussion topics included history-taking and exposure questionnaires, antigen avoidance, environmental assessment, specific inhalational challenge, serum-specific IgG testing, skin testing, lymphocyte proliferation testing, and a multidisciplinary team approach. Priorities for research in this area were identified.

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.

[Adenopathy and mammary carcinoma: It is sometimes in the details that one encounters hypersensitivity pneumonitis!]

INTRODUCTION

Hypersensitivity pneumonitis (HP) is an interstitial lung disease due to an immunological reaction to exposure, by inhalation, to a large variety of antigens. The patho-physiological mechanism remains poorly understood. The diagnosis can be challenging and requires a detailed medical history taking especially when the clinical presentation is atypical or when the causal agent remains unknown.

CASE REPORT

We report the case of a 75-year-old woman with a history of mammary carcinoma who presented with recently identified intramammary adenopathy. Biopsy of the adenopathy revealed non-necrotising, giant cell epithelioid granuloma. A diagnosis of hot tub lung with extra-pulmonary granulomatous lymph node involvement was made based on the clinical, functional, radiological and microbiological investigations. The evolution was favorable following antigen avoidance.

CONCLUSION

Extrapulmonary lymph node involvement is rare in HP, suggesting a systemic inflammatory involvement.

Infectious Lung Disease

Infectious diseases are one of the main causes of morbidity and mortality worldwide. With new pathogens continuously emerging, known infectious diseases reemerging, increasing microbial resistance to antimicrobial agents, global environmental change, ease of world travel, and an increasing immunosuppressed population, recognition of infectious diseases plays an ever-important role in surgical pathology. This becomes particularly significant in cases where infectious disease is not suspected clinically and the initial diagnostic workup fails to include samples for culture. As such, it is not uncommon that a lung biopsy becomes the only material available in the diagnostic process of an infectious disease. Once the infectious nature of the pathological process is established, careful search for the causative agent is advised. This can often be achieved by examination of the hematoxylin and eosin-stained sections alone as many organisms or their cytopathic effects are visible on routine staining. However, ancillary studies such as histochemical stains, immunohistochemistry, in situ hybridization, or molecular techniques may be needed to identify the organism in tissue sections or for further characterization, such as speciation.

[Hypersensitivity pneumonitis and abscess reaction to nontuberculous mycobacteria acquired form jacuzzi aerosol]

INTRODUCTION

Mycobacterium avium complex can be responsible for a number of different radio-clinical presentations, ranging from invasive infections to hypersensitivity pneumonitis due to repeated inhalation of antigens. The diagnosis of hypersensitivity pneumonitis is clinical, radiological, biological and microbiological.

CASE REPORT

A 61-year-old male developed a hypersensitivity pneumonitis reaction to non-tuberculous mycobacteria, following the repeated use of his own spa, which later evolved into chronic respiratory failure. The diagnosis was made via an environmental analysis. Immunosuppressive treatment comprising corticosteroids and methotrexate led to moderate improvement, but may also have been responsible for the development of a M. intracellulare abscess. Despite 12 months of well-conducted antibiotic treatment, the evolution was unfavourable, with a relapse of a M. intracellulare infection three months after the end of treatment, followed by the patient's death.

CONCLUSION

Hypersensitivity pneumonitis reaction to non-tuberculous mycobacteria should be considered in patients who have their own spa. In the absence of microbiological identification, environmental analysis may guide the diagnosis. A fatal evolution of PHS is infrequent but prognosis may depend on the degree of associated fibrosis.

Host Variability in NTM Disease: Implications for Research Needs

Non-tuberculous mycobacteria (NTM) are ubiquitous environmental organisms that may cause opportunistic infections in susceptible hosts. Lung infections in immunocompetent persons with structural lung disease are most common, while disseminated disease occurs primarily in immunocompromised individuals. Human disease caused by certain species, such as Mycobacterium avium complex, Mycobacterium abscessus, and Mycobacterium kansasii, is increasing in incidence and varies by geographic distribution. The spectrum of NTM disease varies widely in presentation and clinical outcome, but certain patterns can be organized into clinical phenotypes. Treatment options are limited, lengthy, and often toxic. The purpose of this case-based review is to provide non-clinician scientists with a better understanding of human NTM disease with an aim to stimulate more research and development.

[Two cases of hot tub lung disease: Environmental investigations]

INTRODUCTION

Hot tub lung is a hypersensitivity pneumonitis (HP) due to exposure to inhaled non-tuberculous mycobacteria, the most frequent being Mycobacterium avium complex (MAC).

CASE REPORT

A French couple developed typicalHP in the context of a repeated use of hot tubs. The husband had a severe hypoxemic form whereas his wife had a micronodular form with patchy ground glass on the thoracic scan, with less severe functional impairment. MAC was recovered in the hot tub water, but not in broncho-alveolar lavage fluid, and serologies were negative. Samples taken at home showed unusual exposure to Aureobasidium pullulans and Aspergillus flavus, as well as the presence of potentially responsible domestic molds. Blood precipitins for these microorganisms were identified. The evolution was favorable after removal of the hot tub.

CONCLUSIONS

These cases represent two of the typical presentations of hot tub lung, with a possible HP to an antigen other than MAC, which may have been enhanced by chronic exposure to multiple microorganisms.

Hot Tub Lung: An Intriguing Diffuse Parenchymal Lung Disease

In pulmonary medicine, identical pathogenesis due to varied etiological agents can present with indistinguishable clinical presentation, and produce similar laboratory and radiological changes. The importance of eliciting detailed occupational and social history from patients cannot be stressed enough when dealing with patients suffering from diffuse parenchymal lung diseases. Hot Tub Lung(HTL) is a perplexing pulmonary disease attributed to the Mycobacterium Avium-intracellulare Complex (MAC). MAC is a ubiquitous atypical mycobacterium present in moist environment, and is not considered pathogenic, without the predisposing conditions like immunosuppression. However, HTL is a unique disease seen in healthy individuals following the exposure to contaminated hot water in spas. The less virulent MAC will, in healthy individual will elicit mild granulomatous inflammation particularly around the peribronchiolar region, which leads to the development of diffuse parenchymal lung. We report a case of HTL to increase the awareness of this rare and enigmatic disease among medical professionals, and to reiterate the importance of eliciting social and occupational details in clinical practice.

[Hot tub lung: A case report]

Hot tub lung is a type of hypersensitivity pneumonitis caused by inhalational exposure to the Mycobacterium avium complex. We report the case of a 14-year-old boy presenting dyspnea with hypoxemia, whose medical history and clinical course helped make the diagnosis. Infectious causes were considered first, and antibiotics were initiated without success. Further questioning and explorations led to discussing a hypersensitivity pneumonitis diagnosis. Relapse after exposure to a hot tub enabled us to confirm hot tub lung. Hypersensitivity pneumonitis is a rare cause of pulmonary disorder, especially in children. It should be discussed with unusually severe and progressive cough or dyspnea. Further explorations should therefore be undertaken (CT, fibroscopy). Taking a precise medical history allows early diagnosis, leading to a quick withdrawal from the allergenic source and appropriate treatments.

Hot Tub Lung: A Diagnostic Challenge

Hot tub lung (HTL) is a granulomatous lung disease thought to occur as a result of a hypersensitivity response to non-tuberculous mycobacteria (NTM). Typical radiographic findings are diffuse micronodular and/or ground glass opacities. We report an interesting case of HTL that presented with unique radiographic features, making its diagnosis a predicament. A 56-year-old immunocompetent female with chronic dyspnea and dry cough was found to have subcentimeter cavitary nodules, predominantly in the upper lung zones. Tissue culture obtained via bronchoscopy was positive for Mycobacterium avium complex (MAC). The patient's clinical and radiographic status, however, deteriorated on antimycobacterial therapy. Complete clinical and radiographic resolution was achieved only after avoidance of hot tub use and treatment with steroids. We believe this is the first reported case of HTL manifesting as cavitary lung nodules with mediastinal lymphadenopathy, and we recommend physicians keep HTL in consideration when encountering patients with these radiographic findings.

A case of hypercalcaemia in an immunocompetent patient with Mycobacterium avium intracellulare

Mycobacterium avium intracellulare infection or colonization should be considered in the differential diagnosis of hypercalcemia, especially in immunocompromised individuals, in the appropriate clinical context.

Successful treatment of acute respiratory failure in a patient with pulmonary Mycobacterium abscessus infection accompanied by organizing pneumonia

Organizing pneumonia (OP) is an inflammatory lung disease characterized pathologically by the presence of buds of granulation tissue in the distal air spaces. There are numerous causes of OP including acute respiratory infections such as viral and bacterial infections. However, Mycobacterium abscessus (M. abscessus) has rarely been reported as a causative pathogen of OP. Here, we report a 67-year-old woman with rapidly progressive pulmonary M. abscessus infection who developed OP and acute respiratory failure (ARF). She was treated successfully with a corticosteroid and anti-mycobacterial therapy. Our observations suggest that pulmonary M. abscessus infection should be added to the list of infectious conditions associated with OP.

Microbiological problems and biofilms associated with Mycobacterium chimaera in heater-cooler units used for cardiopulmonary bypass

The role of heater-cooler units (HCUs) in the transmission of Mycobacterium chimaera during open heart surgery has been recognized since 2013. Subsequent investigations uncovered a remarkable global outbreak reflecting the wide distribution of implicated devices. HCUs are an essential component of cardiopulmonary bypass operations and their withdrawal would severely affect capacity for life-saving cardiac surgery. However, studies have demonstrated that many HCUs are contaminated with a wide range of micro-organisms, including M. chimaera and complex biofilms. Whole genome sequencing of M. chimaera isolates recovered from one manufacturer's HCUs, worldwide, has demonstrated a high level of genetic similarity, for which the most plausible hypothesis is a point source contamination of the devices. Dissemination of bioaerosols through breaches in the HCU water tanks is the most likely route of transmission and airborne bacteria have been shown to have reached the surgical field even with the use of ultraclean theatre ventilation. Controlling the microbiological quality of the water circulating in HCUs and reducing biofilm formation has been a major challenge for many hospitals. However, enhanced decontamination strategies have been recommended by manufacturers, and, although they are not always effective in eradicating M. chimaera from HCUs, UK hospitals have not reported any new cases of M. chimaera infection since implementing these mitigation strategies. Water safety groups in hospitals should be aware that water in medical devices such as HCUs may act as a vector in the transmission of potentially fatal water-borne infections.

Mycobacterium avium Complex Disease

Despite the ubiqitous nature of Mycobacterium avium complex (MAC) organisms in the environment, relatively few of those who are infected develop disease. Thus, some degree of susceptibility due to either underlying lung disease or immunosuppression is required. The frequency of pulmonary MAC disease is increasing in many areas, and the exact reasons are unknown. Isolation of MAC from a respiratory specimen does not necessarily mean that treatment is required, as the decision to treatment requires the synthesis of clinical, radiographic, and microbiologic information as well as a weighing of the risks and benefits for the individual patient. Successful treatment requires a multipronged approach that includes antibiotics, aggressive pulmonary hygiene, and sometimes resection of the diseased lung. A combination of azithromycin, rifampin, and ethambutol administered three times weekly is recommend for nodular bronchiectatic disease, whereas the same regimen may be used for cavitary disease but administered daily and often with inclusion of a parenteral aminoglycoside. Disseminated MAC (DMAC) is almost exclusively seen in patients with late-stage AIDS and can be treated with a macrolide in combination with ethambutol, with or without rifabutin: the most important intervention in this setting is to gain HIV control with the use of potent antiretroviral therapy. Treatment outcomes for many patients with MAC disease remain suboptimal, so new drugs and treatment regimens are greatly needed. Given the high rate of reinfection after cure, one of the greatest needs is a better understanding of where infection occurs and how this can be prevented.

Dose response models and a quantitative microbial risk assessment framework for the Mycobacterium avium complex that account for recent developments in molecular biology, taxonomy, and epidemiology

Mycobacterium avium complex (MAC) is a group of environmentally-transmitted pathogens of great public health importance. This group is known to be harbored, amplified, and selected for more human-virulent characteristics by amoeba species in aquatic biofilms. However, a quantitative microbial risk assessment (QMRA) has not been performed due to the lack of dose response models resulting from significant heterogeneity within even a single species or subspecies of MAC, as well as the range of human susceptibilities to mycobacterial disease. The primary human-relevant species and subspecies responsible for the majority of the human disease burden and present in drinking water, biofilms, and soil are M. avium subsp. hominissuis, M. intracellulare, and M. chimaera. A critical review of the published literature identified important health endpoints, exposure routes, and susceptible populations for MAC risk assessment. In addition, data sets for quantitative dose-response functions were extracted from published in vivo animal dosing experiments. As a result, seven new exponential dose response models for human-relevant species of MAC with endpoints of lung lesions, death, disseminated infection, liver infection, and lymph node lesions are proposed. Although current physical and biochemical tests used in clinical settings do not differentiate between M. avium and M. intracellulare, differentiating between environmental species and subspecies of the MAC can aid in the assessment of health risks and control of MAC sources. A framework is proposed for incorporating the proposed dose response models into susceptible population- and exposure route-specific QMRA models.

[Cutaneous lesions during hot-tub hypersensitivity pneumonitis: Pseudomonas folliculitis ?]

BACKGROUND

Interstitial lung disease, cutaneous rash and elevated serum angiotensin converting enzyme (ACE) may suggest diagnoses other than sarcoidosis.

PATIENTS AND METHODS

A 58-year-old man had presented dyspnoea for 2 years with increased angiotensin-converting enzyme, as well as an interstitial syndrome and micronodules. The possibility of sarcoidosis was raised. Systemic corticosteroids resulted in improvement of the dyspnoea although it recurred on dose reduction. We noted fluctuating eczematous macules of the limbs with a histology of aspecific folliculitis. The identification of Mycobacterium avium complex (MAC) in the bronchoalveolar wash prompted us to initiate antimycobacterial therapy, but this was to no avail. Review of the CT-scan and questioning of the patient (daily use of a Jacuzzi for 7 years) resulted in diagnosis of hypersensitivity pneumonitis due to MAC. The cutaneous lesions were taken to indicate "hot tub folliculitis". Discontinuation of hot-tub use and a short course of oral corticosteroids resulted in healing within 4 months, with no recurrence at 2 years.

DISCUSSION

HTL is a form of hypersensitivity pneumonitis due to the presence of MAC in the water of Jacuzzis. This condition regresses spontaneously without treatment on discontinuation of Jacuzzi use. Hot-tub folliculitis due to Pseudomonas aeruginosa (PA) presents as macules and papules on covered skin areas (swimsuit) within 48hours of bathing and often declines within 2 weeks.

CONCLUSION

Our case is original as regards the concomitant lung and cutaneous involvement associated with Jacuzzi use, with an immunoallergic mechanism for the MAC and probably an infectious mechanism for the PA.

Hypersensitivity pneumonitis in a beautician

A 52-year-old non-smoking beautician using a skincare device spraying steam and ozone (a "vapozone" facial steamer) was referred for progressive dyspnea and dry cough during working periods. Although spirometry was normal, she had decreased diffusing capacity of the lung for carbon monoxide, bronchiolitis with air trapping on high-resolution CT scan and 60% lymphocytosis by bronchoalveolar lavage. Twenty-six antigens were tested and serum-specific precipitins were found mainly against Pseudomonas sp. and Mycobacterium mucogenicum. Cultures from her skincare device isolated Pseudomonas sp. Outcome was favorable with cessation of occupational exposure to the device, without any medication. This is the first report of a case of HP in a beautician due to steam contaminated by Pseudomonas sp. from a vapozone. HP, and not only asthma and contact dermatitis, should be suspected in beauticians with respiratory symptoms. Am. J. Ind. Med. 59:1041-1045, 2016. © 2016 Wiley Periodicals, Inc.

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.

Molecular analysis of idiopathic subglottic stenosis for Mycobacterium species

Objectives/Hypothesis

Idiopathic subglottic stenosis (iSGS) is an unexplained obstruction involving the lower laryngeal and upper tracheal airway. Persistent mucosal inflammation is a hallmark of the disease. Epithelial microbiota dysbiosis is found in other chronic inflammatory mucosal diseases; however, the relationship between tracheal microbiota composition and iSGS is unknown.

Given the critical role for host defense at mucosal barriers, we analyzed tissue specimens from iSGS patients for the presence of microbial pathogens.

Methods

Utilizing 30 human iSGS, 20 intubation‐related tracheal stenosis (iLTS), and 20 healthy control specimens, we applied molecular, immunohistochemical, electron microscopic, immunologic, and Sanger‐sequencing techniques.

Results

With unbiased culture‐independent nucleic acid, protein, and immunologic approaches, we demonstrate that Mycobacterium species are uniquely associated with iSGS. Phylogenetic analysis of the mycobacterial virulence factor rpoB suggests that, rather than Mycobacterium tuberculosis, a variant member of the Mycobacterium tuberculosis complex or a closely related novel mycobacterium is present in iSGS specimens.

Conclusion

These studies identify a novel pathogenic role for established large airway bacteria and provide new targets for future therapeutic intervention.

Level of Evidence

NA Laryngoscope, 127:179–185, 2017

Miliary pulmonary nodules due to Mycobacterium xenopi in a steroid-induced immunocompromised patient successfully treated with chemotherapy: a case report

Background

Mycobacterium xenopi-infected patients have a high prevalence of pulmonary cavities and nodules. However, the clinical course for patients with miliary nodules due to M. xenopi has not yet been reported.

Case presentation

We encountered a case of miliary nodules with gradually worsening coughing and sputum production in a 44-year-old male who had renal dysfunction due to glomerulosclerosis with a decade-long history of steroid therapy. Although we started anti-tuberculosis treatment on clinical suspicion of miliary tuberculosis, cultures of sputum and bronchial lavage were both positive for M. xenopi. The patient was successfully treated with rifampin, ethambutol and clarithromycin, without fibrosis. It was unclear whether the miliary pattern was induced by hematogenous or endobronchial spread of the M. xenopi infection.

Conclusion

Even when clinical and radiological disease manifestations are similar to those of miliary tuberculosis, M. xenopi infection should be considered in the differential diagnosis of miliary nodules.

Pulmonary Disease Caused by Non-Tuberculous Mycobacteria

Non-tuberculous mycobacteria (NTM) include more than 160 ubiquitous, environmental, acid-fast-staining bacterial species, some of which may cause disease in humans. Chronic pulmonary infection is the most common clinical manifestation. Although patients suffering from chronic lung diseases are particularly susceptible to NTM pulmonary disease, many affected patients have no apparent risk factors. Host and pathogen factors leading to NTM pulmonary disease are not well understood and preventive therapies are lacking. NTM isolation and pulmonary disease are reported to rise in frequency in Europe as well as in other parts of the world. Differentiation between contamination, infection, and disease remains challenging. Treatment of NTM pulmonary disease is arduous, lengthy, and costly. Correlations between results of in vitro antibiotic susceptibility testing and clinical treatment outcomes are only evident for the Mycobacterium avium complex, M. kansasii, and some rapidly growing mycobacteria. We describe the epidemiology of NTM pulmonary disease as well as emerging NTM pathogens and their geographical distribution in non-cystic fibrosis patients in Europe. We also review recent innovations for the diagnosis of NTM pulmonary disease, summarize treatment recommendations, and identify future research priorities to improve the management of patients affected by NTM pulmonary disease.

Diagnosis and Treatment of Nontuberculous Mycobacterial Lung Disease

Nontuberculous mycobacteria (NTM) are ubiquitous organisms; their isolation from clinical specimens does not always indicate clinical disease. The incidence of NTM lung diseases has been increasing worldwide. Although the geographic diversity of NTM species is well known, Mycobacterium avium complex (MAC), M. abscessus complex (MABC), and M. kansasii are the most commonly encountered and important etiologic organisms. Two distinct types of NTM lung diseases have been reported, namely fibrocavitary and nodular bronchiectatic forms. For laboratory diagnosis of NTM lung diseases, both liquid and solid media cultures and species-level identification are strongly recommended to enhance growth detection and determine the clinical relevance of isolates. Treatment for NTM lung diseases consists of a multidrug regimen and a long course of therapy, lasting more than 12 months after negative sputum conversion. For MAC lung disease, several new macrolide-based regimens are now recommended. For nodular bronchiectatic forms of MAC lung diseases, an intermittent three-time-weekly regimen produces outcomes similar to those of daily therapy. Treatment of MABC lung disease is very difficult, requiring long-term use of parenteral agents in combination with new macrolides. Treatment outcomes are much better for M. massiliense lung disease than for M. abscessus lung disease. Thus, precise identification of species in MABC infection is needed for the prediction of antibiotic response. Likewise, increased efforts to improve treatment outcomes and develop new agents for NTM lung disease are needed.

A case of familial hot tub lung

Hot tub lung is a lung disease caused by Mycobacterium avium complex. We report the first case of familial hot tub lung appearing simultaneously in a husband and wife. Our case supports the consideration that hot tub lung is a hypersensitivity pneumonitis rather than an infectious lung disease. It also suggests that the state of hot tub lung changes seasonally depending on temperature variations, in a manner similar to summer-type hypersensitivity pneumonitis. This case demonstrates similarities between hot tub lung and summer-type hypersensitivity pneumonitis in regards to familial occurrence and seasonal changes in the disease state.

A case of hypercalcemia secondary to hot tub lung

Hypersensitivity pneumonitis (HP) is a diffuse granulomatous lung disease resulting from inhalation of an antigen to which an individual has been previously sensitized. Hot tub lung is an increasingly common form of HP associated with inhalation of water aerosols containing Mycobacterium avium complex organisms that contaminate hot tub water. Granulomatous lung disorders, most classically sarcoidosis, have been associated with unregulated 1-α-hydroxylase expression by macrophages present in the granulomas, causing conversion of 25-OH-vitamin D to the active form of vitamin D, 1,25(OH)2 vitamin D, and, thus, hypercalcemia. To our knowledge, this is the first confirmed case of hypercalcemia secondary to elevated 1,25(OH)2 vitamin D levels associated with HP.

Strategies for safe living among lung transplant recipients: a single-center survey

BACKGROUND

Lung transplant (LT) recipients are at high risk for infection owing to lifelong immunosuppression and direct communication of the graft with the environment. Guidelines have been established for safe-living strategies after transplantation. We conducted a survey of LT patients to determine compliance with these strategies.

METHODS

Adult LT outpatients completed a survey consisting of questions on a 5-point Likert scale with the following categories: hand washing, gardening, respiratory infections, food and water safety, animal contact, travel, and occupation.

RESULTS

A total of 194 LT recipients completed the survey (age 54.4 ± 13.3 years; time post transplant 4.76 ± 3.5 years). Regular hand washing was practiced usually or always by 87.6%. Of those who worked with soil/gardened, 70/99 (70.7%) never wore a mask and 15.7% never wore gloves. Pet ownership was common (52%), but most patients used specific precautions during handling. Over one-third of patients continued employment after transplant but, of these, 56% had modified their occupation often because of perceived infectious risks. Most patients were fully compliant with influenza vaccination (92.3%). Patients <40 years of age were less likely to wear long-sleeved clothing in mosquito season (P = 0.002), more likely to handle pet feces (P = 0.005), and less likely to wear a mask with sick contacts (P = 0.021).

CONCLUSIONS

We provide important insight into safe-living practices following lung transplantation and identify specific areas and subgroups of patients that could be targeted for enhanced education, with potential significant clinical benefit.