Summer-type hypersensitivity pneumonitis outside Japan: a case report and the state of the art

Database analysis of hypersensitivity pneumonitis in Japan

BACKGROUND

Three epidemiological small-scale studies on hypersensitivity pneumonitis (HP) have been performed in Japan to date. Herein, we aimed to clarify the clinical characteristics of various types of HP diseases using a large nationwide database in Japan.

METHODS

We used the Japanese Diagnostic Procedure Combination database that includes data from 1,031 participant hospitals. Patients with HP from 2011 to 2017 were identified using International Classification of Diseases 10th Revision codes. We analyzed patient characteristics, the yearly transition of the number of HP cases, rate per one million hospitalizations, geographical distribution, seasonality, and risk factors for in-hospital mortality.

RESULTS

In total, 3,634 patients with HP were identified, including summer-type HP (SHP) (n = 490), bird fancier's lung (BFL) (n = 199), ventilation pneumonitis (n = 106), farmer's lung (n = 48), and unspecified HP (n = 2761). The length of hospital stay was significantly longer in patients with BFL (19 days) than in patients with SHP (15 days). SHP was more prevalent in the southwestern region of Japan, and hospitalization occurred mainly in summer (37.8%) and fall (37.3%). Ventilation pneumonitis was predominant in winter (28.6%) and spring (38.7%). In-hospital mortality was significantly associated with old age (p < 0.001), low body mass index (p = 0.016), severe dyspnea (p < 0.001), and BFL diagnosis on admission (p = 0.031).

CONCLUSIONS

This study revealed the clinical characteristics of SHP and BFL, including the frequency of causative antigens, geographical distribution, seasonality, and risk factors for mortality, which may help in diagnosing HP and identifying causative antigens.

Summer-type hypersensitivity pneumonitis in a share house for foreigners in Japan

Summer-type hypersensitivity pneumonitis commonly occurs in Japan during the warm and humid season, when the causative Trichosporon asahii flourish. The assessment of anti-T. asahii antibodies in patients with hypersensitivity pneumonitis without any obvious causative antigen may be useful even outside Japan.

Diagnosis of Hypersensitivity Pneumonitis in Adults. An Official ATS/JRS/ALAT Clinical Practice Guideline

Background: This guideline addresses the diagnosis of hypersensitivity pneumonitis (HP). It represents a collaborative effort among the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax.Methods: Systematic reviews were performed for six questions. The evidence was discussed, and then recommendations were formulated by a multidisciplinary committee of experts in the field of interstitial lung disease and HP using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach.Results: The guideline committee defined HP, and clinical, radiographic, and pathological features were described. HP was classified into nonfibrotic and fibrotic phenotypes. There was limited evidence that was directly applicable to all questions. The need for a thorough history and a validated questionnaire to identify potential exposures was agreed on. Serum IgG testing against potential antigens associated with HP was suggested to identify potential exposures. For patients with nonfibrotic HP, a recommendation was made in favor of obtaining bronchoalveolar lavage (BAL) fluid for lymphocyte cellular analysis, and suggestions for transbronchial lung biopsy and surgical lung biopsy were also made. For patients with fibrotic HP, suggestions were made in favor of obtaining BAL for lymphocyte cellular analysis, transbronchial lung cryobiopsy, and surgical lung biopsy. Diagnostic criteria were established, and a diagnostic algorithm was created by expert consensus. Knowledge gaps were identified as future research directions.Conclusions: The guideline committee developed a systematic approach to the diagnosis of HP. The approach should be reevaluated as new evidence accumulates.

Familial summer-type hypersensitivity pneumonitis in Japan: two case reports and review of the literature

BACKGROUND

Hypersensitivity pneumonitis is defined as an allergic lung disease that occurs in response to inhalation of fungal antigens, bacterial antigens, chemicals, dusts, or animal proteins. The incidence of summer-type hypersensitivity pneumonitis is higher in the summer season, especially in Japan, due to the influence of the hot and humid environment and the common style of wood house or old concrete condominiums.

CASE PRESENTATION

The present report describes a case of a middle-aged married couple who lived in the same house and who simultaneously suffered from summer-type hypersensitivity pneumonitis. This report analyzes these two cases in terms of environmental research and its microbiological, radiological, and pathological aspects. This case report is followed by a review of family occurrences of summer-type hypersensitivity pneumonitis from 22 studies with a total of 49 patients (including the two present cases) in Japan.

CONCLUSION

Summer-type hypersensitivity pneumonitis may be unrecognized and misdiagnosed as pneumonia or other respiratory diseases. A greater understanding of the clinical, pathologic, and environmental features of summer-type hypersensitivity pneumonitis might help improve diagnosis and delivery of appropriate management for this condition.

Current knowledge of Trichosporon spp. and Trichosporonosis

Trichosporon spp. are basidiomycetous yeast-like fungi found widely in nature. Clinical isolates are generally related to superficial infections. However, this fungus has been recognized as an opportunistic agent of invasive infections, mostly in cancer patients and those exposed to invasive medical procedures. It is possible that the ability of Trichosporon strains to form biofilms on implanted devices, the presence of glucuronoxylomannan in their cell walls, and the ability to produce proteases and lipases are all factors likely related to the virulence of this genus and therefore may account for the progress of invasive trichosporonosis. Disseminated trichosporonosis has been increasingly reported worldwide and represents a challenge for both diagnosis and species identification. Phenotypic identification methods are useful for Trichosporon sp. screening, but only molecular methods, such as IGS region sequencing, allow the complete identification of Trichosporon isolates at the species level. Methods for the diagnosis of invasive trichosporonosis include PCR-based methods, Luminex xMAP technology, and, more recently, proteomics. Treating patients with trichosporonosis remains a challenge because of limited data on the in vitro and in vivo activities of antifungal drugs against clinically relevant species of the genus. Despite the mentioned limitations, the use of antifungal regimens containing triazoles appears to be the best therapeutic approach.

A case of hypersensitivity pneumonitis caused by Penicillium species in a home environment

We report a case of hypersensitivity pneumonitis in a 30-yr-old female housewife caused by Penicillium species found in her home environment. The patient was diagnosed according to history, chest radiograph, spirometry, high-resolution chest CT, and transbronchial lung biopsy. To identify the causative agent, cultured aeromolds were collected by the open-plate method. From the main fungi cultured, fungal antigens were prepared, and immunoblot analysis with the patient's serum and each fungal antigen was performed. A fungal colonies were isolated from the patient's home. Immunoblotting analysis with the patient's sera demonstrated a IgG-binding fractions to Penicillium species extract, while binding was not noted with control subject. This study indicates that the patient had hypersensitivity pneumonitis on exposure to Penicillium species in her home environment.

Structural studies of a cell wall polysaccharide of Trichosporon asahii containing antigen II

The structure of a cell-wall polysaccharide containing antigen II from Trichosporon asahii was investigated. A purified glucuronoxylomannan (GXM) antigen was found to contain O-acetyl groups that contribute to the serological reactivity. The structure of GXM was analyzed by partial acid hydrolysis, methylation analysis, controlled Smith degradation, NMR studies, and fluorophore-assisted carbohydrate electrophoresis. GXM has an alpha-(1-->3)-D-mannan backbone with a beta-D-glucopyranosyluronic acid residue bound to O-2 of a mannopyranosyl residue and the same number of beta-D-xylopyranosyl residues as mannose. Side chains of beta-D-xylopyranosyl-D-xylopyranose, forming a nonreducing terminus, and beta-D-xylopyranosyl residues were attached to O-2, O-4, and O-6 of the mannose residues.

Genetic diversity and biochemical characteristics of Trichosporon asahii isolated from clinical specimens, houses of patients with summer-type-hypersensitivity pneumonitis, and environmental materials

Trichosporon asahii, which is distributed in the environment, is the major causative agent of the opportunistic infection trichosporonosis, and it also causes summer-type hypersensitivity pneumonitis (SHP). Random amplification of polymorphic DNA analysis was used to determine the intraspecies diversity of 39 T. asahii isolates from clinical specimens, SHP patients' houses, and environmental materials. The three primers used revealed 46 polymorphic bands. A phenogram was generated by the unweighted pair-group method with arithmetic mean. Clinical isolates formed a cluster, characterized by a 90% matching coefficient, but they did not cluster with strains isolated from SHP patients' houses or environmental sources. In addition, the biochemical characteristics of 86 strains from three sources were examined with 31 compounds using an ID32C kit, and a phenogram was constructed. The phenogram consisted of three major clusters. Cluster I included most of the clinical SHP isolates, and cluster II included most of the environmental isolates. Cluster III contained only one strain. A remarkable difference was found in the abilities of the strains belonging to clusters I and II to utilize six compounds. These results suggest that the genetic diversity and biochemical characteristics of T. asahii seem to be related to the source of the isolate. We also found a specific DNA fragment for the clinical isolates and strains isolated from SHP patients' houses.

Hypersensitivity pneumonitis caused by Fusarium napiforme in a home environment

BACKGROUND

We report a case of hypersensitivity pneumonitis (HP) in a 17-year-old male student caused by Fusarium napiforme found in his home environment.

METHODS

The patient was diagnosed according to history, chest radiograph, spirometry, high-resolution chest CT, and transbronchial lung biopsy. To identify the causative agent, cultured aeromolds were collected by the open-plate method. From the main fungi cultured, fungal antigens were prepared, and immunoblot analysis with the patient's serum and each fungal antigen was performed.

RESULTS

Five fungal species were isolated from the patient's home. Immunoblotting analysis with the patient's serum demonstrated more than 10 IgG-binding fractions to F. napiforme extract only, while little binding was noted with the other fungal antigens.

CONCLUSIONS

We should be aware that HP may be caused by F. napiforme in the home environment.