Trichosporon asahii-induced asthma in a family with Japanese summer-type hypersensitivity pneumonitis

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.

An unusual but unmissable link between summer-type hypersensitivity pneumonitis and asthma in an old house

While hypersensitivity pneumonitis (HP) and asthma are usually recognized as different disease entities based on their different allergic mechanisms, they may have some connections. A previously healthy 54-year-old Japanese man with no history of allergic diseases was hospitalized due to fever and breathlessness. He had lived in an old musty wooden house. He was diagnosed with acute summer-type HP induced by Trichosporon asahii based on bilateral ground-glass opacities on chest computed tomography (CT), a high titer of serum anti-T. asahii antibody, an increased number of lymphocytes and a decreased CD4/CD8 ratio in bronchoalveolar lavage fluid (BALF) and lung pathology suggestive of HP. However, untypical increased eosinophils in BALF (25.2%) and infiltrative eosinophils around bronchial walls were observed. After systemic corticosteroid treatment was started, he recovered, and was discharged with oral prednisone. However, two weeks after returning to his former house, he had fever and severe cough, and was re-hospitalized. While chest CT showed no abnormal shadows indicating a worsening of HP, pulmonary function test revealed a typical obstructive defect and eosinophilic inflammation in his sputum. He spontaneously recovered after re-hospitalization without increasing any treatments. During this second hospitalization, he was diagnosed with asthma, although it remains to be determined whether both HP and asthma were caused by T. asahii. Clinicians should not miss the possible overlapping presentations between HP and asthma, caused by environmental antigens.

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.

Familial Summer-type Hypersensitivity Pneumonitis: A Review of 25 Families and 50 Cases in Japan

Summer-type hypersensitivity pneumonitis (SHP) is the most common form of pneumonitis in Japan; it accounts for 74% of all cases. It has been reported that 19.5-23.8% of SHP cases occur in families who live in the same house. We present our SHP cases and review 50 familial cases in 23 families that were reported in Japan (including our own) and 48 cases that were previously described in 22 articles published between January 1982 and October 2011. To the best of the authors' knowledge, this is the first review article in English to document the familial occurrence of SHP in Japan.

Hypersensitivity pneumonitis secondary to residential exposure to Aureobasidium pullulans in 2 siblings

BACKGROUND

Hypersensitivity pneumonitis (HP) is an immune-mediated hypersensitivity reaction to a variety of inhaled particles that may lead to acute, subacute, or chronic interstitial pneumonitis and possibly end-stage lung disease. Avian antigens most commonly cause HP in children, but fungi have also been implicated.

OBJECTIVE

To describe a 15-year-old girl and her 6-year-old brother who developed HP from residential exposure to Aureobasidium pullulans.

METHODS

Allergy skin testing, serum precipitating antibodies, pulmonary function testing, chest radiography, chest computed tomography, bronchoalveolar lavage, and a home survey for possible causative antigens were performed.

RESULTS

Both patients lived on a horse farm and had fatigue, weight loss, cough, and dyspnea. The siblings had restrictive patterns on pulmonary function tests, with decreased diffusion capacity of carbon monoxide, ground-glass opacities on high-resolution chest computed tomography, and serum precipitins to A pullulans. Bronchoalveolar lavage in the girl demonstrated lymphocytosis, with a preponderance of CD8+ T cells and natural killer cells. Symptoms improved after the children vacated the home and recurred on repeated exposure in both patients. Home evaluation revealed extensive mold contamination, with A pullulans counts of 659, 329, and 71 CFU/m3 in the boy's bedroom, the girl's bedroom, and outdoors, respectively.

CONCLUSIONS

The diagnosis of HP in these siblings is supported by the clinical history, the diagnostic findings, and the recurrence of symptoms on repeated exposure. These cases represent the second report of HP resulting from nonoccupational exposure to A pullulans in North America and the first report in children.

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.

Cork workers' occupational asthma: lack of association with allergic sensitisation to fungi of the work environment

OBJECTIVES

To evaluate allergic sensitisation to Chrysonilia sitophila, Penicillium glabrum, and Trichoderma longibrachiatum in cork workers with asthma.

METHODS

Skin prick tests with a battery of common allergens and with the three fungi were performed on ten cork workers with asthma and eight non-exposed asthmatics. Based on serial peak expiratory flow measurements, five were classified as having occupational asthma (AO) and five as having non-occupational asthma (NOA). In exposed patients, specific antibodies for the three fungi were also studied by immunoblotting

RESULTS

Two out of ten patients with occupational exposure and four out of eight of the control group showed positive results for skin prick tests for common allergens. Moreover, two out of five patients with OA and three out of eight controls exhibited sensitisation to storage mites. All exposed patients (with OA or NOA) had negative skin prick test results for the fungal extracts. In patients with asthma and occupational exposure, immunoblotting results confirmed the absence of specific IgE. However, specific IgG4 was present in some cases.

CONCLUSIONS

Atopy does not seem to characterise occupational asthma in cork workers. Despite their long exposure to moulds, we could not find evidence of IgE sensitisation to the three most prevalent cork fungi in patients with OA, which points to the search for other causative agents, such as cork chemical compounds or contaminants.