Bronchiolitis Pattern Research Articles

Nontuberculous mycobacterial pulmonary disease presenting as bronchiolitis pattern on CT without cavity or bronchiectasis

BackgroundThis study aimed to investigate the radiological changes in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) having bronchiolitis patterns on computed tomography (CT).MethodsWe retrospectively reviewed the final diagnosis and radiologic changes of patients suspected of having NTM-PD without cavity or bronchiectasis on CT image, between January 1, 2005 and March 31, 2021. NTM-PD was diagnosed based on the American Thoracic Society and Infectious Diseases Society of America criteria. The initial and final CT findings (bronchiectasis, cellular bronchiolitis, cavity formation, nodules, and consolidation) were compared between patients diagnosed with and without NTM-PD.ResultsThis study included 96 patients and 515 CT images. The median CT follow-up duration was 1510.5 (interquartile range: 862.2–3005) days. NTM-PD was recognized in 43 patients. The clinical variables were not significantly different between patients with and without NTM-PD, except for underlying chronic airway disease (P < 0.001). Nodule and consolidation were more frequently observed on the initial CT scans of patients with NTM-PD compared with those without (P < 0.05). On the final follow-up CT scan, bronchiectasis (P < 0.001), cavity (P < 0.05), nodule (P < 0.05), and consolidation (P < 0.05) were more frequently observed in patients with NTM-PD. Among the 43 patients with NTM-PD, 30 showed a radiological progression on CT, with bronchiectasis (n = 22) being the most common finding. The incidence of bronchiectasis increased over time.ConclusionThe bronchiolitis pattern on CT images of patients with NTM-PD showed frequent radiological progression during the follow-up period.

Determinants of radiological patterns and severity in immunocompromised adults with Metapneumovirus infection

BackgroundHuman Metapneumovirus (HMPV) belongs to the Pneumoviridae family and is responsible for respiratory infections. Mild infections are well-recognized in children, while its precise impact in various categories of immunocompromised adults has not been well addressed. Research questionWe retrospectively studied HMPV infections in immunocompromised adults followed in two large French university medical centers. Study design and methodsWe identified immunocompromised adults with positive HMPV Polymerase Chain Reaction (PCR) for 36 months and reviewed their medical charts. For lung transplant recipients (LTR), FEV1 was collected at baseline, during and after infection. Imaging was centralized and chest involvement was categorized by dominant CT patterns. We compared severe patients (requiring oxygen or ventilation) and non hypoxemic patients. ResultsSeventy-two patients were included, 27 were LTR, 25 had a hematological malignancy or were hematopoietic stem cell recipients, 20 had another immunocompromised status. Twenty patients (28%) presented a hypoxemic infection, requiring hospitalization and intensive care units transfers in 50/72 (69.4%) and 9/72 (12.5%) respectively, with only one death. Hypoxemia was less pronounced in LTRs (p = 0.014). Finally, age and dyspnea remained independent factors associated with hypoxemia (p < 0.005). The most frequent radiological patterns were bronchopneumonia (34.2%) and bronchiolitis (39.5% and 64.3% in the overall population and in LTRs respectively, p = 0.045). FEV1 improved in LTRs at one month and 85% had recovered their baseline FEV1 within 6 months. InterpretationsIn immunocompromised adults, HMPV infections required frequent hospitalizations and ICU transfers, while mortality is low. In LTRs, bronchiolitis pattern was predominant with short and long-term favorable outcome.

Changes in Bronchiolitis Incidence During the Last Two Decades in Tampere, Finland: A Retrospective Study.

Background:Bronchiolitis, a lower respiratory tract infection, causes a remarkable number of hospitalizations globally. The epidemiology follows the same pattern as respiratory syncytial virus (RSV), the most common pathogen in bronchiolitis. Epidemics have typically followed a biannual pattern in Nordic countries—first, a small epidemic during spring, followed by a higher peak the next autumn. The aim of this study was to evaluate whether the incidence of bronchiolitis hospitalization has changed during the last 2 decades in Tampere, Finland.Methods:In this retrospective register-based study, data on infants <12 months of age hospitalized with bronchiolitis in 2000–2019 were collected from electronic files of Tampere University Hospital and analyzed by monthly incidences. Additionally, data on RSV incidences were collected from the Finnish National Infectious Diseases Register for children <5 years of age and living in the study area. Poisson’s regression analysis was used to evaluate changes in the incidence rates of bronchiolitis.Results:Of the 1481 infants hospitalized with bronchiolitis, 82.0% had a diagnosis of RSV bronchiolitis. At first, bronchiolitis’ epidemiological pattern followed its typical biannual pattern, then shifted to annual in the middle of the study period, and thereafter occurred biannually again. The highest incidence rate ratios compared to the low-incidence months were between December (22.5), January (25.8) and February (25.5) in 2000–2006, and between February (24.7), March (25.1) and April (21.0) in 2007–2019.Conclusions:The epidemiological pattern of bronchiolitis changed during the study period; incidence peaks were higher and have shifted toward spring in recent years.

Severe lung disease characterized by lymphocytic bronchiolitis, alveolar ductitis, and emphysema (BADE) in industrial machine-manufacturing workers.

A cluster of severe lung disease occurred at a manufacturing facility making industrial machines. We aimed to describe disease features and workplace exposures. Clinical, functional, radiologic, and histopathologic features were characterized. Airborne concentrations of thoracic aerosol, metalworking fluid, endotoxin, metals, and volatile organic compounds were measured. Facility airflow was assessed using tracer gas. Process fluids were examined using culture, polymerase chain reaction, and 16S ribosomal RNA sequencing. Five previously healthy male never-smokers, ages 27 to 50, developed chest symptoms from 1995 to 2012 while working in the facility's production areas. Patients had an insidious onset of cough, wheeze, and exertional dyspnea; airflow obstruction (mean FEV1 = 44% predicted) and reduced diffusing capacity (mean = 53% predicted); and radiologic centrilobular emphysema. Lung tissue demonstrated a unique pattern of bronchiolitis and alveolar ductitis with B-cell follicles lacking germinal centers, and significant emphysema for never-smokers. All had chronic dyspnea, three had a progressive functional decline, and one underwent lung transplantation. Patients reported no unusual nonoccupational exposures. No cases were identified among nonproduction workers or in the community. Endotoxin concentrations were elevated in two air samples; otherwise, exposures were below occupational limits. Air flowed from areas where machining occurred to other production areas. Metalworking fluid primarily grew Pseudomonas pseudoalcaligenes and lacked mycobacterial DNA, but 16S analysis revealed more complex bacterial communities. This cluster indicates a previously unrecognized occupational lung disease of yet uncertain etiology that should be considered in manufacturing workers (particularly never-smokers) with airflow obstruction and centrilobular emphysema. Investigation of additional cases in other settings could clarify the cause and guide prevention.

The emerging spectrum of exposure-related bronchiolitis.

Exposure-related bronchiolitis is increasingly recognized as an important but challenging clinical diagnosis. Acute and chronic inhalational exposures are associated with variable clinical presentations and a spectrum of histopathologic abnormalities affecting the small airways. This review provides an overview of the histologic patterns and occupational settings for exposure-related bronchiolitis, along with recent advances in disease diagnosis and management. The entire histopathologic spectrum of bronchiolitis (constrictive, obliterative, proliferative, lymphocytic, respiratory) has been reported in exposure-related bronchiolitis. Recent studies have shown that lung clearance index testing and impulse oscillometry are more sensitive than spirometry in detecting small airways abnormalities and may augment the diagnosis of occupational bronchiolitis. Prognosis in indolent occupational bronchiolitis appears more favorable than some other types of bronchiolitis but is variable depending on the extent of bronchiolar inflammation and the stage of disease at which exposure removal occurs. No specific histopathologic pattern of bronchiolitis is pathognomonic for occupational bronchiolitis as one or more histologic patterns may be present. A high index of suspicion is needed for exposure and disease recognition. Recent advances that may aid in diagnosis include transbronchial cryobiopsy, lung clearance index testing, and impulse oscillometry, although further research is needed.

Computed tomography findings of aspiration pneumonia in 53 patients

No large case series has so far shown the chest computed tomography (CT) features in patients with aspiration pneumonia, despite the fact that aspiration pneumonia is the most common pulmonary disease in the elderly and is regarded as gravity-dependent pneumonia. The aim of the present study was to elucidate the CT features based on the patients' status in patients with dysphagia-associated aspiration pneumonia. A total of 53 patients, who were hospitalized because of pneumonia and subsequently confirmed to have dysphagia by videofluorography, were entered into this study. The CT findings were independently evaluated by two radiologists who were unaware of the patients' clinical information. The relationships between the patients' status and the CT patterns of pneumonia or their distributions were analyzed. There were eight patients (15%) with lobar pneumonia, 36 patients (68%) with bronchopneumonia and nine patients (17%) with bronchiolitis. Posterior lung predominance was seen in 49 patients (92%). In the craniocaudal observation, lower lung predominance was found in 25 patients (47%) and diffuse distribution was seen in 28 patients (53%). A decreased performance status was significantly associated with a diffuse distribution (P=0.039). Aspiration pneumonia more frequently presented as a bronchopneumonia pattern followed by a bronchiolitis pattern on CT. Their distributions were characterized by gravity dependence, and anterior- or upper lung-limited pneumonia might not be due to dysphagia-associated pneumonia.

Diffuse bronchiolitis pattern on a computed tomography scan as a presentation of pulmonary tumor thrombotic microangiopathy: a case report

IntroductionPulmonary tumor thrombotic microangiopathy is a rare complication of malignant diseases. The diagnosis is extremely difficult and is most often performed after death. Invariably, patients develop acute pulmonary hypertension causing right heart failure, shortness of breath and death in a few days. We describe the clinical and radiological findings of a patient who presented with this complication.Case presentationA 28-year-old Caucasian woman with a previous history of pelvic tumor resection two months previously, suggestive of metastatic adenocarcinoma, presented with intense shortness of breath. A computed tomography scan showed signs of acute cor pulmonale and diffuse nodular opacities associated with a tree-in-bud pattern disseminated through her lungs, suggestive of bronchiolitis. Our patient's condition worsened and she underwent a surgical biopsy. Pathologic analysis of the biopsied specimens revealed pulmonary tumor thrombotic microangiopathy. Our patient's tumor evolved from a gastric origin (Krukenberg tumor). She underwent progressive clinical deterioration and died less than 24 hours after the biopsy. None of the cases described previously in the literature had diffuse centrilobular nodular opacities associated with a tree-in-bud pattern disseminated through the lungs, as in our case.ConclusionPulmonary tumor thrombotic microangiopathy should be considered in cancer patients with rapidly progressing dyspnea, chest computed tomography findings compatible with pulmonary hypertension and typical findings of inflammatory bronchiolitis.

Small airway obstruction in patients with rheumatoid arthritis

This work was intended to evaluate the prevalence of obstructive small-airway disease in patients with rheumatoid arthritis (RA) and its association with clinical characteristics. Pulmonary function testing (PFT) and high-resolution computed tomography (HRCT) were performed on 189 consecutive RA patients. Each case was diagnosed based on abnormal HRCT findings. We defined obstructive dysfunction of small airways as a forced expiratory flow from 25% to 75% of vital capacity (FEF25–75) value >1.96 residual standard deviation (RSD) below predicted values. We found 19 patients (10.1%) with an interstitial pneumonia (IP) pattern and 15 (7.9%) with a bronchiolitis pattern; the other 155 (82.0%) had no abnormal HRCT patterns. In patients with neither abnormal pattern, median values of percentage predicted for carbon monoxide diffusing capacity (DLCO) and ratio of DLCO to alveolar ventilation (DLco/VA) were within the normal range, but median FEF25–75, forced expiratory flow at 25% of vital capacity (V25), and V25/height were <70% of predicted values. Forty-seven patients (30.3%) in this group had obstructive small-airway dysfunction. Multivariate logistic regression analysis indicated that this type of abnormality is strongly associated with respiratory symptoms [odds ratio (OR) 5.18; 95% confidence interval (CI) 1.70–15.75; p = 0.012), smoking history (OR 2.78; 95% CI 1.10–6.99; p = 0.03), and disease duration >10 years (OR 2.86; 95% CI 1.27–6.48; p = 0.012). Parenchymal micronodules, bronchial-wall thickening, and bronchial dilatation on HRCT scans were also predictive factors for abnormal FEF25–75, although these morphological changes were too limited for us to diagnose these patients with the bronchiolitis pattern. Obstructive dysfunction of small airways is apparently common among RA patients, even among those with neither the IP nor the bronchiolitis pattern on HRCT scans. Factors significantly associated with abnormal FEF25–75 are respiratory symptoms, smoking history, and RA duration.

Small airway obstruction in patients with rheumatoid arthritis.

This work was intended to evaluate the prevalence of obstructive small-airway disease in patients with rheumatoid arthritis (RA) and its association with clinical characteristics. Pulmonary function testing (PFT) and high-resolution computed tomography (HRCT) were performed on 189 consecutive RA patients. Each case was diagnosed based on abnormal HRCT findings. We defined obstructive dysfunction of small airways as a forced expiratory flow from 25% to 75% of vital capacity (FEF25–75) value >1.96 residual standard deviation (RSD) below predicted values. We found 19 patients (10.1%) with an interstitial pneumonia (IP) pattern and 15 (7.9%) with a bronchiolitis pattern; the other 155 (82.0%) had no abnormal HRCT patterns. In patients with neither abnormal pattern, median values of percentage predicted for carbon monoxide diffusing capacity (DLCO) and ratio of DLCO to alveolar ventilation (DLco/VA) were within the normal range, but median FEF25–75, forced expiratory flow at 25% of vital capacity (V25), and V25/height were <70% of predicted values. Forty-seven patients (30.3%) in this group had obstructive small-airway dysfunction. Multivariate logistic regression analysis indicated that this type of abnormality is strongly associated with respiratory symptoms [odds ratio (OR) 5.18; 95% confidence interval (CI) 1.70–15.75; p = 0.012), smoking history (OR 2.78; 95% CI 1.10–6.99; p = 0.03), and disease duration >10 years (OR 2.86; 95% CI 1.27–6.48; p = 0.012). Parenchymal micronodules, bronchial-wall thickening, and bronchial dilatation on HRCT scans were also predictive factors for abnormal FEF25–75, although these morphological changes were too limited for us to diagnose these patients with the bronchiolitis pattern. Obstructive dysfunction of small airways is apparently common among RA patients, even among those with neither the IP nor the bronchiolitis pattern on HRCT scans. Factors significantly associated with abnormal FEF25–75 are respiratory symptoms, smoking history, and RA duration.

Drs. Mori and Cho reply

We thank Dr. Georgiadis and colleagues for their comments on our study1. We are pleased that our findings have attracted the interest of readers, and we offer the following response. First, Georgiadis, et al state that we reported no significant differences in HRCT findings between patients with early RA and those with longstanding RA, but we think that this is a misinterpretation. We performed HRCT on a total of 126 patients with either early RA (n = 65) or longstanding RA (n = 61). Abnormalities on HRCT imaging were categorized, and the frequency of each finding and its extent in the lungs were compared between the 2 patient populations. We found that the frequency of interstitial abnormalities such as ground-glass attenuation, reticulation, honeycombing, and consolidation was not significantly different between the 2 groups. Yet it is important to recall that, in contrast, there were significant differences in the frequencies of parenchymal micronodules and bronchial wall thickening, both of which are indicative of small-airway diseases; specifically, these conditions were more prominently observed in the patients with longstanding RA, which tendency apparently contributed to the higher incidence of the bronchiolitis pattern in this group. We therefore concluded that the incidence of bronchiolar abnormalities is associated with the duration of RA. The longstanding RA group appeared to be predisposed to complications … Address reprint requests to Dr. S. Mori, Clinical Research Center for Rheumatic Disease and Department of Rheumatology, Kumamoto Saishunsou National Hospital, 2659 Suya, Kohshi, Kumamoto 861-1196, Japan. E-mail: moris{at}saisyunsou1.hosp.go.jp

Lower respiratory tract infection of positive antigen test for respiratory syncytial virus on children under 2 years of age

Purpose:This study was design and performed for evaluations of resent clinical pattern of bronchiolitis caused by RSV infection with children under 2 year of age for 5 years, who were admitted to pediatric ward. Methods:The inclusion criteria of the patients were children under 24 month-of-age, clinical manifestations of lower respiratory tract infection, and RSV antigen that was detected by a direct immunofluorescence test from the nasal secretions. The additional laboratory and simple chest X-ray findings were reviewed from the medical records of children who were admitted Wonkwang university hospital from Jan. 1999 to Dec. 2003. Results:In the 5 year study duration, 127 patients were enrolled and outbreak of RSV bronchiolitis took place in 2001. The 80 cases(63 percent) of RSV infection were concentrated in later autumn and winter. Number of the cases show coughing were 120(94.5 percent), but rale was audible in 78 cases(61.4 percent). Dyspnea, wheezing, and intercostal retraction were noticed in 27(21.3 percent), 21(16.5 percent), and 4(3 percent) cases respectively. The most common chest X-ray finding was hyperinflation of the lung that was noticed in 110 cases(86.6 percent). Care with mechanical ventilator for more than 2 days required in 5 cases. Conclusion:Lower respiratory tract infection by RSV was common in late autumn and winter season but year-round infection was noticed. The severity of RSV respiratory tract infectiontakes in some degree a grave course. So we suggest that population-based surveillance of acute respiratory infection due to RSV is necessary for assessment of prevalence and epidemiology of this disease.

Acute bronchiolitis in tropical Africa: a hospital-based perspective in Ibadan, Nigeria.

In a 30-month prospective study of severe acute lower respiratory infections in hospitalized pre-school Nigerian children, acute bronchiolitis was diagnosed in 67 cases; 19 (28.4%) and 2 (3.0%) of these had concomitant pneumonia or croup, respectively. The peak prevalence was in the wet (rainy) season (May-October). The male/female (M:F) ratio in infants < or = 6 months was 2.9:1, differing significantly from the 1.1:1 in older subjects (P = 0.04). None of the subjects had severe malnutrition. Neither a high fever (> or = 39 degrees C), nor tachypnea on admission was significantly correlated with co-existing pneumonia. Of the 29 subjects in whom it was possible to explore viral immunofluorescence studies and/or serodiagnosis, we identified 26 viral identifications in 18 (62.1%) cases; 6 (20.7%) had > or = 2 viruses. Respiratory syncytial virus was identified in 11 (38.0%) of the 29 cases, and parainfluenza virus (PIV) types 1, 2, and 3 in 10 (34.5%). PIV type 3 accounted for 7 cases, including 3 with bacteremia. Bacterial isolates were made in 9 (21.4%) of 42 blood cultures and in the only lung aspirate; Staphylococcus epidermidis and Staphylococcus aureus accounted for 4 and 3 cases, respectively. Although bacteremia was 2.9 times more common in cases with co-existing pneumonia or croup, the respective frequency of virus-positive cases and that of bacteremia was not significantly different between cases with bronchiolitis alone and those with associated pneumonia or croup. No deaths were recorded, but subjects aged > 6 months had a significantly shorter hospital stay than those < 6 months old (P = 0.02). Despite the limited sample size, our findings reflect the etiological importance of the paramyxoviruses and the seasonal pattern of bronchiolitis in tropical Africa.