Hypersensitivity pneumonia-nonspecific interstitial pneumonia/fibrosis histopathologic presentation: a study in diagnosis and long-term management

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.

Frequency of goose and duck down causation of hypersensitivity pneumonitis within an 80-patient cohort

BACKGROUND

A variety of antigens have been identified as causative of hypersensitivity pneumonitis (HP), which is characterized by inflammation to the lung parenchyma that is induced by exposure. Goose and duck down (GDD) bedding is often overlooked by physicians as a potential cause, yet the use of GDD has markedly increased in recent years, paralleling an increased frequency of reports of GDD-induced HP.

OBJECTIVE

To determine the frequency of GDD as the causative antigen in patients with HP who use bedding that contains GDD.

METHODS

Patients referred with a working diagnosis of HP underwent a detailed environmental history. Those who were using GDD were asked to remove it as an avoidance procedure. Signs, symptoms, spirometry, and inflammatory markers were followed up at weekly intervals for up to 1 month to determine the effect of remediation.

RESULTS

Eighty patients with HP were seen during an 8-year period. Thirty-two patients (40%) were using GDD bedding. Of these 32 patients, 12 (37.5% of those exposed and 15% of the total HP population experienced remission (or nonprogression) of disease by simply avoiding GDD bedding. Eleven (92%) of these 12 patients were female. In patients with GDD-induced HP, lung biopsy patterns were varied.

CONCLUSION

Approximately one-third of patients with HP, who slept with GDD, had persistent improvement or remission with simple avoidance. The higher incidence of GDD-induced HP in females may be hormonal and/or sociocultural related. Lung biopsy findings were across the spectrum of histopathologic patterns. Avoidance-challenge techniques were effective in confirming diagnoses and causation and mitigating the need for additional remediation.

Nonspecific interstitial pneumonia: clinical associations and outcomes

Background

Studies have shown that nonspecific interstitial pneumonitis (NSIP), even when initially diagnosed as an idiopathic form of the disease, might be associated with an autoimmune background that later reveals itself as an organ-specific or a systemic autoimmune disease.

Methods

NSIP patients were divided into three groups. The NSIP patients who met the criteria for having a systemic autoimmune disease (SAD) were defined as the systemic autoimmune disease-associated NSIP (SAD-NSIP) group. The NSIP patients who did not meet the criteria for a systemic autoimmune disease were defined as an antibody-positive group (i-NSIP-Ab + group) if their sera were positive for autoantibodies. The NSIP patients with negative serologic tests for auto-antibodies were defined as the antibody-negative group (i-NSIP-Ab- group). The clinical characteristics were analyzed and compared among the three groups.

Results

Ninety-seven NSIP patients were included. The mean age of the study population was 48 ± 11 years. The mean follow-up time was 54 ± 34 months. At the time of the surgical lung biopsies, 23/97 (23.7%) of the patients were classified as SAD-NSIP; 30/97 (30.9%) were in the i-NSIP-Ab + group; and 44/97 (45.4%) were in the i-NSIP-Ab- group. At the end of the follow-up period, three cases were diagnosed with polymyositis (one case from the i-NSIP-Ab + group, two cases from the i-NSIP-Ab- group), one with scleroderma (from the i-NSIP-Ab + group, scl-70 positive and skin biopsy) and another one with microscopic polyarteritis (from the i-NSIP-AB-group, p-ANCA and MPO positive, renal biopsy). Three cases in the i-NSIP-Ab- group were later found to be positive for autoantibodies. Due to these changes in classification, at the end of the follow-up period, the SAD-NSIP group consisted of 28/97 patients (28.9%), the i-NSIP-Ab + group of 31/97 (32.0%) and the i-NSIP-Ab- group of 38/97(39.1%). There were no significant differences in clinical manifestations, radiographic findings or pulmonary function tests among the three groups at the time of surgical lung biopsy or after reclassification after the follow-up period. SAD was an independent risk factor for the survival of the patients with NSIP after follow-up.

Conclusion

Follow-up is recommended because idiopathic NSIP may be the first manifestation of a systemic autoimmune disease.

Fungal pollution of indoor environments and its management

Indoor environments play important roles in human health. The health hazards posed by polluted indoor environments include allergy, infections and toxicity. Life style changes have resulted in a shift from open air environments to air tight, energy efficient, environments, in which people spend a substantial portion of their time. Most indoor air pollution comes from the hazardous non biological agents and biological agents. Fungi are ubiquitous in distribution and are a serious threat to public health in indoor environments. In this communication, we have reviewed the current status on biotic indoor air pollution, role of fungi as biological contaminants and their impact on human health.

Fungal pollution of indoor environments and its management

Indoor environments play important roles in human health. The health hazards posed by polluted indoor environments include allergy, infections and toxicity. Life style changes have resulted in a shift from open air environments to air tight, energy efficient, environments, in which people spend a substantial portion of their time. Most indoor air pollution comes from the hazardous non biological agents and biological agents. Fungi are ubiquitous in distribution and are a serious threat to public health in indoor environments. In this communication, we have reviewed the current status on biotic indoor air pollution, role of fungi as biological contaminants and their impact on human health.

Hypersensitivity pneumonitis: beyond classic occupational disease-changing concepts of diagnosis and management

OBJECTIVE

To review inhaled antigens in home environments that cause hypersensitivity pneumonitis (HP) of varied clinical expressions and histopathologic patterns.

DATA SOURCES

Computer-assisted MEDLINE and manual searches for articles concerning HP, interstitial lung disease (ILD), epidemiology of HP and ILD, challenge procedures of HP, and indoor fungi.

STUDY SELECTION

Published articles concerning inhaled antigens in home environments and HP were selected.

RESULTS

Current criteria for the diagnosis of HP are too restrictive, because most apply only to the classic acute presentation and are of limited value in the subacute and insidious forms. Clinical expressions vary across the gamut of respiratory tract signs and symptoms. Patterns on lung biopsy may include all histopathologic descriptions of idiopathic ILD. The home is the likely causative environment rather than the workplace. Exposures may be occult and require in-depth environmental histories and on-site investigations to detect antigens and sources.

CONCLUSIONS

Natural or environmental challenges have become an important tool for diagnosing HP and determining effectiveness of remediation. Early diagnosis and effective remediation of the cause lead to a high survival rate, whereas diagnosis in advanced stages leads to disability and/or premature death.

Nonspecific interstitial pneumonia: a real clinical entity?

Based on the current multidisciplinary classification of idiopathic interstitial pneumonia (IIP) organized by ATS/ERS, nonspecific interstitial pneumonia (NSIP) is considered as one type of IIP. An incidence of idiopathic NSIP is relatively small and possesses clinical features that are different than idiopathic pulmonary fibrosis (IPF) and usual interstitial pneumonia (UIP). Because there is little evidence of a long-term prognosis in patients with NSIP, some of them have an unfavorable prognosis similar to IPF/UIP. We review the significance of prognostic factors that have been reported in patients with IPF/UIP by applying them to patients with NSIP. The association with collagen vascular diseases focuses on etiologic background. Finally, the article discusses whether NSIP could be an early lesion of UIP based on the reported evidence and our own professional experiences.

Toxic mold: phantom risk vs science

OBJECTIVE

To review the available literature on the subject of fungi (molds) and their potential impact on health and to segregate information that has scientific validity from information that is yet unproved and controversial.

DATA SOURCES

This review represents a synthesis of the available literature in this area with the authors' collective experience with many patients presenting with complaints of mold-related illness.

STUDY SELECTION

Pertinent scientific investigation on toxic mold issues and previously published reviews on this and related subjects that met the educational objectives were critically reviewed.

RESULTS

Indoor mold growth is variable, and its discovery in a building does not necessarily mean occupants have been exposed. Human response to fungal antigens may induce IgE or IgG antibodies that connote prior exposure but not necessarily a symptomatic state. Mold-related disease has been discussed in the framework of noncontroversial and controversial disorders.

CONCLUSIONS

When mold-related symptoms occur, they are likely the result of transient irritation, allergy, or infection. Building-related illness due to mycotoxicosis has never been proved in the medical literature. Prompt remediation of water-damaged material and infrastructure repair should be the primary response to fungal contamination in buildings.

Recent advances in the diagnosis and management of nonspecific interstitial pneumonia

Idiopathic interstitial pneumonia is a heterogeneous group of diseases. Recently, the importance of a detailed differentiation of nonspecific interstitial pneumonia from other idiopathic interstitial pneumonias has been demonstrated. Most critical appeared to be a proper classification based on clinical presentation, high-resolution CT findings, bronchoalveolar lavage fluid cell findings, and histopathology. This classification may guide the most appropriate therapeutic approach and has significant implications regarding prognosis. Recent advances in the diagnosis and management of nonspecific interstitial pneumonia, cellular and fibrosing variants, are discussed.