Diffuse Aspiration Bronchiolitis Research Articles

"Tree-in-bud" opacities with false-positive Gaffky score and diffuse aspiration bronchiolitis.

We present a case of diffuse aspiration bronchiolitis (DAB) with a false-positive Gaffky score. "Tree-in-bud" opacities detected after aspiration should be considered DAB rather than mycobacterial infection.

Chronic Microaspiration and Frailty: A Geriatric Smoking Gun?

Chronic microaspiration and diffuse aspiration bronchiolitis may account for some otherwise unexplained frailty in nursing home patients.

Recent advances in the understanding of bronchiolitis in adults.

Bronchiolitis is injury to the bronchioles (small airways with a diameter of 2 mm or less) resulting in inflammation and/or fibrosis. Bronchioles can be involved in pathologic processes that involve predominantly the lung parenchyma or large airways, but, in some diseases, bronchioles are the main site of injury (“primary bronchiolitis”). Acute bronchiolitis caused by viruses is responsible for most cases of bronchiolitis in infants and children. In adults, however, there is a wide spectrum of bronchiolar disorders and most are chronic. Many forms of bronchiolitis have been described in the literature, and the terminology in this regard remains confusing. In clinical practice, a classification scheme based on the underlying histopathologic pattern (correlates with presenting radiologic abnormalities) facilitates the recognition of bronchiolitis and the search for the inciting cause of the lung injury. Respiratory bronchiolitis is the most common form of bronchiolitis in adults and is usually related to cigarette smoking. Currently, the diagnosis of respiratory bronchiolitis is generally achieved based on the clinical context (smoking history) and chest CT findings. Constrictive (obliterative) bronchiolitis is associated with airflow obstruction and is seen in various clinical contexts including environmental/occupational inhalation exposures, transplant recipients (bronchiolitis obliterans syndrome), and many others. Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) is increasingly recognized and can be associated with progressive airflow obstruction related to constrictive bronchiolitis (“DIPNECH syndrome”). Diffuse aspiration bronchiolitis is a form of aspiration-related lung disease that is often unsuspected and confused for interstitial lung disease. Novel forms of bronchiolitis have been described, including lymphocytic bronchiolitis and alveolar ductitis with emphysema recently described in employees at a manufacturing facility for industrial machines. Bronchiolitis is also a component of vaping-related lung injury encountered in the recent outbreak.

特発性肺線維症に合併したびまん性誤嚥性細気管支炎の 1 例

特発性肺線維症に合併したびまん性誤嚥性細気管支炎の 1 例

Diffuse aspiration bronchiolitis: analysis of 20 consecutive patients.

OBJECTIVE: Aspiration can cause a variety of pulmonary syndromes, some of which are not well recognized. The objective of this study was to assess the demographic, clinical, radiological, and histopathological correlates of diffuse aspiration bronchiolitis (DAB), a bronchiolocentric disorder caused by recurrent aspiration. METHODS: This was a retrospective study of 20 consecutive patients with DAB seen at the Mayo Clinic in Rochester, Minnesota, between January 1, 1998 and June 30, 2014. RESULTS: The median age of the patients was 56.5 years (range, 22-76 years), and the male/female ratio was 2.3:1.0. In 18 patients, the diagnosis of DAB was based on the results of a lung biopsy; in the 2 remaining patients, it was based on clinical and radiological features, together with documented aspiration observed in a videofluoroscopic swallow study. In 19 patients (95%), we identified predisposing factors for aspiration, including gastroesophageal reflux disease (GERD), drug abuse, and dysphagia. Common presenting features included cough, sputum production, dyspnea, and fever. Twelve patients (60%) had a history of recurrent pneumonia. In all of the patients, chest CT revealed bilateral pulmonary infiltrates consisting of micronodules and tree-in-bud opacities. In the majority of patients, interventions aimed at preventing recurrent aspiration (e.g., anti-GERD therapies) led to improvement in the symptoms of DAB. CONCLUSIONS: Young to middle-aged subjects with recognizable predisposing factors for aspiration and who report a history of recurrent pneumonia are at increased risk for DAB. Although DAB is not well recognized, certain chest CT features are characteristic of the disorder.

Aspiration-Related Pulmonary Syndromes

Aspiration of foreign matter into the airways and lungs can cause a wide spectrum of pulmonary disorders with various presentations. The type of syndrome resulting from aspiration depends on the quantity and nature of the aspirated material, the chronicity, and the host responses. Aspiration is most likely to occur in subjects with a decreased level of consciousness, compromised airway defense mechanisms, dysphagia, gastroesophageal reflux, and recurrent vomiting. These aspiration-related syndromes can be categorized into airway disorders, including vocal cord dysfunction, large airway obstruction with a foreign body, bronchiectasis, bronchoconstriction, and diffuse aspiration bronchiolitis, or parenchymal disorders, including aspiration pneumonitis, aspiration pneumonia, and exogenous lipoid pneumonia. In idiopathic pulmonary fibrosis, aspiration has been implicated in disease progression and acute exacerbation. Aspiration may increase the risk of bronchiolitis obliterans syndrome in patients who have undergone a lung transplant. Accumulating evidence suggests that a causative role for aspiration is often unsuspected in patients presenting with aspiration-related pulmonary diseases; thus, many cases go undiagnosed. Herein, we discuss the broadening spectrum of these pulmonary syndromes with a focus on presenting features and diagnostic aspects.

Aspiration-related lung diseases.

Aspiration is a common but underrecognized clinicopathologic entity, with varied radiographic manifestations. Aspiration represents a spectrum of diseases, including diffuse aspiration bronchiolitis, aspiration pneumonitis, airway obstruction by foreign body, exogenous lipoid pneumonia, interstitial fibrosis, and aspiration pneumonia with or without lung abscess formation. Many patients who aspirate do not present with disease, suggesting that pathophysiology is related to a variety of factors, including decreased levels of consciousness, dysphagia, impaired mucociliary clearance, composition of aspirate, and impaired host defenses. In this pictorial essay, we will review the different types of aspiration lung diseases, focusing on their imaging features and differential diagnosis.

Nine pulmonary aspiration syndrome cases of atypical clinical presentation, in which the final diagnosis was obtained by histological examinations

While pulmonary aspiration syndrome (PAS) is primarily clinically diagnosed, atypical PAS cases can be misdiagnosed clinically and are more accurately diagnosed histologically. To elucidate clinicopathological features of these rare cases, we examined PAS cases determined by histological examination of transbronchial lung biopsy (TBLB) specimens. Of 6105 TBLB cases investigated from 1990 to 2007, 11 were diagnosed as PAS based on histology. Of these, we examined 9 records in detail, as the medical records for 2 cases were unavailable. Histopathological findings indicated 8 patients with aspiration pneumonia and 1 with diffuse aspiration bronchiolitis. However, the pre-bronchoscopy diagnoses included lung cancer, mycobacteriosis, organizing pneumonia, repetitive pneumonia, fungal infection, and interstitial pneumonia. PAS was not considered before TBLB. Only 4 of the 9 patients developed subjective symptoms including fever and cough with sputum production. Laboratory findings demonstrated elevation of white blood cell (WBC) count in only 1 patient and elevation of C reactive protein (CRP) level in 4 patients. Radiographic examination revealed abnormal findings in the dorsal right lower lobes, which was the most vulnerable site for aspiration pneumonia, and also in the upper and ventral portions of the lung. Although the characteristic findings of PAS were scarce, all patients had conditions predisposing to aspiration; i.e., gastrectomy, excessive alcohol drinking, post-cerebral infarction, and sinobronchial syndrome. We diagnosed 9 PAS patients on the basis of histological findings that were distinct from clinical findings. Despite presenting with variable symptoms and laboratory and radiographic findings, they all exhibited predisposing factors to aspiration.

Clinical Significance of Aspiration Pneumonia and Diffuse Aspiration Bronchiolitis in the Elderly

Aspiration Pneumonia (AP) and Diffuse Aspiration Bronchiolitis (DAB) are often found in elderly, debilitated patients with dysphagia. The prevalence of AP in hospitals and nursing homes is rapidly expanding. The incidence of AP to total pneumonia is very high in elderly patients aged 70 years and older. For the diagnosis of AP or DAB, the evaluation of swallowing function is important. Food aspiration alone may cause DAB, but not always cause AP. Two different therapeutic approaches such as antibiotics administration and swallowing rehabilitation with oral hygiene are necessary for the cure of AP. Drugs that improve the swallowing reflex, vaccinations and oral health care management are effective in preventing aspiration pneumonia; however, percutaneous endoscopic gastrostomy is not recommended for the purpose of preventing aspiration pneumonia. The proper management of AP and DAB may be a central issue of geriatric medicine.

Pulmonary aspiration syndromes

Pulmonary aspiration syndromes are a common cause of morbidity and mortality. These syndromes are often misdiagnosed and their management is frequently suboptimal. This paper reviews the clinical features and management of the most common aspiration syndromes. Pulmonary aspiration syndromes refer to a group of pulmonary diseases resulting from aspiration of foreign material into the lung. The type of syndrome depends on the quantity and nature of the aspirated material as well as its chronicity. The most common syndromes include aspiration pneumonia, diffuse aspiration bronchiolitis, and aspiration pneumonitis. Aspiration pneumonia and diffuse aspiration bronchiolitis generally occur in elderly, debilitated patients with dysphagia and usually present as 'community acquired pneumonia', which tends to be recurrent in patients with diffuse aspiration bronchiolitis. Treatment consists of broad-spectrum antibiotics and management of the underlying dysphagia. Aspiration pneumonitis follows the aspiration of gastric contents, usually in patients with a marked decreased level of consciousness. Treatment of aspiration pneumonitis is essentially supportive; however, corticosteroids and other immunomodulating agents may have a role in these patients. Aspiration syndromes are common with their management dictated by the type of aspiration syndrome.

Can Maximum Intensity Projection Images With Multidetector-Row Computed Tomography Help to Differentiate Between the Micronodular Distribution of Focal and Diffuse Infiltrative Lung Diseases?

The objective of this study was to evaluate whether maximum intensity projection (MIP) images increased the ability of experienced and resident radiologists to differentiate between the micronodular distribution of focal and diffuse infiltrative lung diseases. The cases used in the study were those of 26 patients with focal or diffuse micronodular lung diseases, including 7 cases of sarcoidosis, 6 of miliary tuberculosis, 3 of pulmonary tuberculosis, 3 of chronic bronchitis, 2 of human T-lymphotropic virus type 1-associated bronchoalveolar disorder, 2 of diffuse aspiration bronchiolitis, 1 of atypical mycobacterial infection, and 1 of lymphangitic carcinomatosis. Scans of the entire lung during a single breath hold at 1.25-2.5 mm thickness and a pitch of 6 were performed using a multidetector-row computed tomography (MDCT) apparatus with a 4-row detector. Additional MIP image slabs were produced from the initial axial images on all study patients on a workstation according to a protocol that incorporated a slab thickness of 10 mm, a reconstructed interval of 10 mm, and a window width of -1500 Hounsfield units. The ability of 10 radiologists (5 board-certified radiologists and 5 radiology residents) to interpret contiguous thin-section CT scans and additional MIP images was then studied in an observer performance study. The results of both sets of observer performances were compared using receiver operating characteristic analysis. In the resident observers, the mean area under the receiver operating characteristic curve (Az) value increased significantly from 0.654 without the MIP images to 0.753 with the MIP images (P < 0.01). In the board-certified radiologists, however, the mean Az values remained unchanged at 0.867 without the MIP images and 0.846 with the MIP images. This study showed that MIP images may help radiologists in training to differentiate between the micronodular distribution of focal and diffuse infiltrative lung diseases.

Clinical, Radiologic, and Pathologic Findings in Diffuse Aspiration Bronchiolitis

PURPOSE: Diffuse aspiration bronchiolitis (DAB) represents a clinical entity characterized by chronic bronchiolar inflammation resulting from recurrent aspiration of food particles. Autopsy studies suggest that DAB occurs mainly in elderly, debilitated patients that are known to have dysphagia and at risk for aspiration. We reviewed four cases of evaluated at our institution in an attempt to further characterize the clinical, radiologic, and histopathologic aspects of this condition.

多発・長期停留した気管支異物症例

Chronic pulmonary disease of the elderly caused by frequent aspiration has been recognized in the recent Japanese literatures. We report an elderly case with cerebrovascular disease who had long-term bronchial foreign bodies and had been treated for “asthma” for years. He was taken to an emergency room because of a dyspnea which occurred at breakfast. Fiberscopy showed a bean-like foreign body in his right main bronchus. Using ventilation bronchoscopy, we removed not only this pulse but a piece of fish vertebra from his right main bronchus and another older one coated by granulation tissue from his left superior lobar bronchus. A chest x-ray of this patient showed a diffusely scattered nodular shadow in the right lower lung field; this finding resembled that of diffuse aspiration bronchiolitis (DAB). He showed a multiple brain infarct on MR imaging. A low signal-intensity area in the white matter of the left supra orbital gyrus on T1 weighted image might be related to his characteristic aspiration. We assumed the fine crackle in his lung fields and his continuous productive cough had been caused by frequent aspiration. In the elderly, some patients could have latent aspiration but be incorrectly diagnosed as asthma or other pulmonary diseases. When we meet elderly patients with moist rale and productive cough, we must consider the possibility of chronic pulmonary disease caused by aspiration. There is a need to develop for testing and treating methods for these patients.

Importance of Diffuse Aspiration Bronchiolitis Caused by Chronic Occult Aspiration in the Elderly

Diffuse aspiration bronchiolitis (DAB) is a new term that we proposed to define a clinical entity that is characterized by a chronic inflammation of bronchioles caused by recurrent aspiration of foreign particles. In the present study, a total of 4,880 consecutive autopsies were reviewed and we found 31 patients with DAB (0.64%). To investigate the clinicopathologic features of DAB, the 23 patients with DAB (age, 81.2 +/- 6.2 years [mean +/- SD]), from whom clinical information was available, had their features compared to those of 40 randomly selected patients with aspiration pneumonia (age, 81.9 +/- 8.3 years [mean +/- SD]). Oropharyngeal dysphagia was observed in half of the patients with DAB, and two thirds of patients with DAB were bedridden. The onset of DAB was more insidious than aspiration pneumonia, and in half of the patients with DAB episodes of aspiration were unrecognized. Neurologic disorders (52.2%) and dementia (47.8%) were common associated diseases. Most patients with DAB showed signs of bronchorrhea, bronchospasm, and dyspnea. The macroscopic appearance of the cut surface of DAB lung showed diffusely scattered miliary yellowish nodules that resembled those of diffuse panbronchiolitis (DPB). Histologic findings of DAB were characterized by localization of chronic mural inflammation with foreign body reaction in bronchioles. Recurrence of small amounts of aspiration might play a role in the pathogenesis of DAB. In view of possible therapeutic intervention, we emphasized the importance of recognizing this entity and differentiating DAB from pulmonary diseases associated with bronchospasm in the elderly, in particular, late-onset asthma and DPB.

Detection of human T lymphotropic virus type I proviral DNA in patients with diffuse panbronchiolitis.

In Japan a number of reported cases of diffuse panbronchiolitis (DPB) have been associated with human T lymphotropic virus type I (HTLV-I) infection. In this study the hypothesis that HTLV-I proviral DNA may be prevalent in DPB was examined using polymerase chain reaction (PCR) for the region of env or the two-step PCR for the pX region of this virus. The presence of HTLV-I proviral DNA was studied in the peripheral blood mononuclear cells (PBMC) obtained from 10 patients with DPB. The presence of proviral DNA in PBMC in 12 patients with chronic obstructive pulmonary disease (COPD), eight patients with idiopathic interstitial pneumonia (IIP), four patients disease were also studied as relevant controls. The lung tissue obtained from 11 patients with DPB, 12 patients with diffuse aspiration bronchiolitis (DAB) at autopsy, and the surgical lung samples obtained from 12 patients with bronchogenic cancer were also studied. Peripheral blood mononuclear cells obtained from one DPB patient and one bronchogenic carcinoma patient were positive for the HTLV-I pX region. The presence of the pX region was also found in the lung tissue of three DPB patients (27.3%) and one DAB patient (8.3%). None of other subjects were positive for HTLV-I proviral DNA, In conclusion, HTLV-I is not the causative virus in the pathogenesis of COPD, IIP, bronchiectasis and bronchogenic carcinoma. There is a likelihood that HTLV-I infection is associated with some cases of DPB; however this association needs further verification.

上部消化管運動機能の障害 えん下性肺炎

Aspiration pneumonia is caused by materials inhaled into the lower respiratory tract, such as gastric juice or food particles. In adults, most of the patients have a swallowing disturbance such as bulbar palsy or a consciousness disturbance as well as a reduced cough reflex.Acute aspiration pneumonia caused by gastric juice is sometimes referred to as the“Mendelson syndrome”, which is a chemical injury to the broncho-alveolar epithelium and vascular endothelium. Food particles from the oral cavity or stomach, which are usually contaminated with resident bacteria from the oral cavity or pharynx, subsequently cause bacterial infections and sometimes even lung abscesses. One kind of chronic aspiration pneumonia which is similar to diffuse pan-bronchiolitis (DPB), is called diffuse aspiration bronchiolitis (DAB), is due to continuous small amount of aspiration.It is important to diagnose aspiration pneumonia immediately and to start its treatment at an early stage.

Diffuse aspiration bronchiolitis (DAB) produced in animals by repeated HCl microaspiration

We recently reported that diffuse aspiration bronchiolitis (DAB) was detected in 1% of autopsied lungs of aged cases of pneumonia. We hypothesized whether repeated HCl micro-aspiration (RHMA) is involved in DAB and established an animal model by administering HCl intratracheally to rats every two days for 2 weeks. Saline was given to control animals in the same fashion. Then, we performed bronchio-alveolar lavage (BAL) or excised lungs for histologic examination. There was no difference in BAL cell counts, TNF alpha-production, elastase-like activity or albumin levels between the HCl and control groups. Histologically, DAB-like findings were observed in the HCl-treated animals. These data suggest that RHMA might be involved in DAB, while neither TNF alpha-production nor elastase-like activity may play a significant role in inducing DAB.