Masahide Yasui

Immunoglobulin G4–related Lung Disease: CT Findings with Pathologic Correlations

PURPOSE To retrospectively analyze radiologic findings of immunoglobulin G4 (IgG4)-related lung disease as correlated with pathologic specimens. MATERIALS AND METHODS This study was approved by the institutional review board, and all patients had consented to the use of their medical records for the purpose of research. This study included 13 patients with IgG4-related lung disease (nine men and four women; age range, 43-76 years). Computed tomographic (CT) findings were retrospectively analyzed with regard to the characteristics, shape, and distribution of the radiologic findings and were correlated with surgically resected or biopsy lung specimens in seven patients. Statistical analysis was not used in this study. RESULTS On the basis of the predominant radiologic abnormality, IgG4-related lung disease could be categorized into four major subtypes: solid nodular type having a solitary nodular lesion that included a mass (four patients); round-shaped ground-glass opacity (GGO) type characterized by multiple round-shaped GGOs (two patients); alveolar interstitial type showing honeycombing, bronchiectasis, and diffuse GGO (two patients); and bronchovascular type showing thickening of bronchovascular bundles and interlobular septa (five patients). Pathologically, solitary nodular lesions consisted of diffuse lymphoplasmacytic infiltration with fibrosis. Thickened bronchovascular bundles or interlobular septa and GGO on CT images pathologically corresponded to lymphoplasmacytic infiltration and fibrosis in peribronchiolar or interlobular interstitium and alveolar interstitium, respectively. The radiologic findings of honeycombing corresponded to disrupted alveolar structures and dilated peripleural air spaces. CONCLUSION IgG4-related lung disease manifested as four major categories of CT features. Pathologically, these features corresponded to IgG4-related sclerosing inflammation along the intrapulmonary connective tissue.

Eosinophilic tracheobronchitis and airway cough hypersensitivity in chronic non‐productive cough

We have shown that some patients presenting with chronic bronchodilator‐resistant non‐productive cough have global atopic tendency and airway cough hypersensitivity without non‐specific bronchial hyperresponsiveness, abbreviated as atopic cough. The cough is successfully treated with histamine H1‐antagonists and/or glucocorticoids.

Characterization of increased cough sensitivity after antigen challenge in guinea pigs

Increased sensitivity of cough reflex is a fundamental feature of bronchodilator resistant non‐productive cough associated with eosinophilic tracheobronchitis. Our hypothesis is that cough sensitivity is increased by airway allergic reaction characterized by airway eosinophilic inflammation. The aim of this study was to elucidate the hypothesis and clarify the characteristics of the increased cough sensitivity.

Intercellular adhesion molecule-1 and L-selectin regulate bleomycin-induced lung fibrosis.

The development of bleomycin-induced lung injury, a model of pulmonary fibrosis, results from inflammatory cell infiltration, a process highly regulated by the expression of multiple adhesion molecules. At present, the identity and role of the adhesion molecules involved in the fibrotic process are unknown. Therefore, bleomycin-induced pulmonary fibrosis was examined in mice lacking L-selectin (L-selectin(-/-)) expression, intercellular adhesion molecule-1 (ICAM-1) expression, or both. After 16 days of intratracheal bleomycin challenge, collagen deposition was inhibited in both L-selectin(-/-) and ICAM-1(-/-) mice when compared with wild-type littermates. Interestingly, collagen deposition was virtually eliminated in L-selectin/ICAM-1(-/-) mice relative to either the L-selectin(-/-) or ICAM-1(-/-) mice. Decreased pulmonary fibrosis was associated with reduced accumulation of leukocytes, including neutrophils and lymphocytes. Decreased mRNA expression of proinflammatory cytokines and transforming growth factor (TGF)-beta1 paralleled the inhibition of collagen deposition. The present study indicates that L-selectin and ICAM-1 play a critical role in pulmonary fibrosis by mediating the accumulation of leukocytes, which regulate the production of proinflammatory cytokines and TGF-beta1. This suggests that these adhesion molecules are potential therapeutic targets for inhibiting human pulmonary fibrosis.

Atopy in cough sensitivity to capsaicin and bronchial responsiveness in young females

We have shown previously that female sex is a determinant of cough sensitivity to inhaled capsaicin, but the relationship between atopy and the cough sensitivity has not been examined. The capsaicin cough threshold, defined as the lowest concentration of capsaicin causing five or more coughs, nonspecific bronchial responsiveness, defined as the provocative concentration of methacholine causing a 20% fall in the forced expiratory volume in one second (PC20), total immunoglobulin E (IgE) and specific IgEs to eight common aeroallergens (house dust 1, 2 and 6, Dermatophagoides pteronyssinus and D. farinae, Japanese cedar, ragweed and orchard grass) in the serum were measured in 71 nonsmoking, healthy young women aged 20.6+/-0.1 yrs (mean+/-EM). A structured interviewer-led questionnaire on allergic diseases revealed that one and six subjects had mild current and past asthma, respectively. These seven subjects were excluded from the data analysis. PC20 was significantly lower in 42 subjects showing a positive specific IgE than in 22 subjects showing a negative specific IgE to any of the eight allergens (p<0.05), while the capsaicin cough threshold was not significantly different between the subgroups. PC20 was significantly lower in subjects with positive specific IgE to Dermatophagoides and house dust, but not to the three kinds of pollen examined. It was confirmed that atopy indicated by specific immunoglobulin E to mite-related antigens, but not to pollen antigens, is associated with nonspecific bronchial responsiveness, and it is suggested that atopy is not a determinant of airway cough sensitivity in healthy, nonasthmatic subjects.

Bronchoalveolar lavage cell findings in three types of eosinophilic pneumonia: acute, chronic and drug-induced eosinophilic pneumonia

There are clinically different types of eosinophilic pneumonia (EP) but no study to date has compared pulmonary inflammatory cells between different types of EP, such as acute eosinophilic pneumonia (AEP), chronic eosinophilic pneumonia (CEP) and drug-induced eosinophilic pneumonia (drug-EP). The present study compared bronchoalveolar lavage fluid (BALF) cell findings to elucidate whether the profiles of the pulmonary inflammatory cells were different among the three types of EP. Clinical records of 28 patients with EP, consisting of eight AEP patients, 10 CEP patients and 10 drug-EP patients, were examined retrospectively. The differential cell counts, the CD4+/CD8+ ratio of lymphocytes, the percentage of HLA-DR+ in CD4+ and CD8+ lymphocytes, and the mean number of nuclear segmentations in cosinophils in BALF were compared among the three types of EP. The numbers of total cells, lymphocytes, neutrophils and eosinophils in BALF from patients with AEP were increased compared with those from normal subjects, and patients with CEP and drug-EP. The CD4+/CD8+ ratio of the BALF lymphocytes in patients with AEP, which exceeded 1.0 in all patients, was significantly higher than that in normal subjects. The percentages of HLA-DR+ cells in CD8+ lymphocytes in BALF from patients with CEP were significantly higher than those from patients with AEP and drug-EP. There was no significant difference in the mean number of nuclear segmentations in eosinophils in BALF among the three types of EP. The BALF cell findings in patients with EP showed some characteristics in accordance with type of EP. It is suggested that pulmonary neutrophils and lymphocytes, rather than eosinophils, may be related to the pathogenesis of the different types of EP.

The specific chymase inhibitor TY-51469 suppresses the accumulation of neutrophils in the lung and reduces silica-induced pulmonary fibrosis in mice

ABSTRACT Chymase is a chymotrypsin-like serine protease that is present in mast cells. Its activities include various effects associated with inflammatory responses. But little is known about the effects of chymase in pulmonary fibrosis. The mouse silicosis model was induced by intratracheal injection of 10 mg silica. The Ashcroft pathological score and the hydroxyproline content of lungs were measured to evaluate the effect of a chymase inhibitor, 2-[4-(5-fluoro-3-methylbenzo[b]thiophen-2-yl)sulfonamido-3-methanesulfonylphenyl] thiazole-4-carboxylic acid (TY-51469). The cellular composition and cytokine levels in bronchoalveolar lavage fluid (BALF) were also examined. Following TY-51469 treatment, the lung fibrosis score and hydroxyproline level were significantly reduced, and the number of neutrophils and the levels of macrophage inflammatory protein-2, monocyte chemoattractant protein-1, and transforming growth factor-β1 in BALF were reduced on day 21. The administration of TY-51469 at an early stage showed a greater reduction of fibrosis compared to administration at a later stage. The neutrophil number in BALF in mice treated with TY-51469 both at an early stage and late stage was significantly reduced. The level of mouse mast cell proteinase-4 mRNA increased with time in silica-induced fibrosing lung tissue. These results show that the chymase inhibitor TY51469 suppresses the migration of neutrophils, which results in the suppression of lung fibrosis.

Angiotensin II type 2 receptor antagonist reduces bleomycin-induced pulmonary fibrosis in mice

BackgroundThe role of angiotensin II type 2 receptor (AT2) in pulmonary fibrosis is unknown. To evaluate the influence of angiotensin II type 1 receptor (AT1) and AT2 antagonists in a mouse model of bleomycin (BLM)-induced pulmonary fibrosis.MethodsWe examined effects of the AT1 antagonist (AT1A) olmesartan medoxomil (olmesartan) and the AT2 antagonist (AT2A) PD-123319 on BLM-induced pulmonary fibrosis, which was evaluated by Ashcrofts pathological scoring and hydroxyproline content of lungs. We also analyzed the cellular composition and cytokine levels in bronchoalveolar lavage fluid (BALF).ResultsWith olmesartan, the lung fibrosis score and hydroxyproline level were significantly reduced, and lymphocyte and neutrophil counts and tumor necrosis factor (TNF)-α levels in BALF were reduced on day 7. On day 14, macrophage and lymphocyte counts in BALF were reduced, accompanied by a reduction in the level of transforming growth factor (TGF)-β1. With PD-123319, the lung fibrosis score and hydroxyproline level were reduced. On day 7, macrophage, lymphocyte, and neutrophil counts in BALF were reduced, accompanied by reductions in TNF-α and monocyte chemoattractant protein (MCP)-1 levels. On day 14, macrophage, lymphocyte, and neutrophil counts in BALF were also reduced, accompanied by a reduction in the level of macrophage inflammatory protein (MIP)-2 level but not TGF-β1.ConclusionBoth AT1 and AT2 are involved in promoting interstitial pneumonia and pulmonary fibrosis via different mechanisms of action.

Evaluation of pulmonary function using breathing chest radiography with a dynamic flat panel detector : Primary results in pulmonary diseases

Objectives:Dynamic flat panel detectors (FPD) permit acquisition of distortion-free radiographs with a large field of view and high image quality. The present study was performed to evaluate pulmonary function using breathing chest radiography with a dynamic FPD. We report primary results of a clinical study and computer algorithm for quantifying and visualizing relative local pulmonary airflow. Materials and Methods:Dynamic chest radiographs of 18 subjects (1 emphysema, 2 asthma, 4 interstitial pneumonia, 1 pulmonary nodule, and 10 normal controls) were obtained during respiration using an FPD system. We measured respiratory changes in distance from the lung apex to the diaphragm (DLD) and pixel values in each lung area. Subsequently, the interframe differences (D-frame) and difference values between maximum inspiratory and expiratory phases (D-max) were calculated. D-max in each lung represents relative vital capacity (VC) and regional D-frames represent pulmonary airflow in each local area. D-frames were superimposed on dynamic chest radiographs in the form of color display (fusion images). The results obtained using our methods were compared with findings on computed tomography (CT) images and pulmonary functional test (PFT), which were examined before inclusion in the study. Results:In normal subjects, the D-frames were distributed symmetrically in both lungs throughout all respiratory phases. However, subjects with pulmonary diseases showed D-frame distribution patterns that differed from the normal pattern. In subjects with air trapping, there were some areas with D-frames near zero indicated as colorless areas on fusion images. These areas also corresponded to the areas showing air trapping on computed tomography images. In asthma, obstructive abnormality was indicated by areas continuously showing D-frame near zero in the upper lung. Patients with interstitial pneumonia commonly showed fusion images with an uneven color distribution accompanied by increased D-frames in the area identified as normal on computed tomography images. Furthermore, measurement of DLD was very effective for evaluating diaphragmatic kinetics. Conclusions:This is a rapid and simple method for evaluation of respiratory kinetics for pulmonary diseases, which can reveal abnormalities in diaphragmatic kinetics and regional lung ventilation. Furthermore, quantification and visualization of respiratory kinetics is useful as an aid in interpreting dynamic chest radiographs.

Pulmonary manifestations of anti-ARS antibody positive interstitial pneumonia – With or without PM/DM

BACKGROUND Autoantibodies against aminoacyl-tRNA synthetases (ARS) have been found to be highly specific for polymyositis and dermatomyositis (PM/DM) and to correlate strongly with complicating interstitial pneumonia (IP). The aim of the present study was to compare the clinical presentations of anti-ARS antibody-positive IP patients with or without manifestations of PM/DM. METHODS We retrospectively examined 36 IP patients with anti-ARS antibodies. Sixteen patients presented with and 20 without the features of PM/DM. They were divided into PM/DM-IP and idiopathic-IP (IIP) groups. Clinical symptoms, findings on physical examination, laboratory data, pulmonary function, computed tomography (CT), and bronchoalveolar lavage fluid (BALF) cell counts were compared. RESULTS Skin findings, myalgia, and elevation of serum creatinine kinase were found in the PM/DM-IP group. Features common to both groups included: volume loss in lower bilateral lobes; ground-glass opacities, reticular shadows and traction bronchiectasis on chest CT; high percentage of lymphocytes (IIP: 44.0% ± 21.0% (mean ± SD), PM/DM-IP: 50.5% ± 23.5%) and low CD4/8 ratios (IIP: 0.36 ± 0.34, PM/DM-IP: 0.44 ± 0.42) in BALF; decreased pulmonary function, including percentage of predicted vital capacity (VC) (IIP: 80.1% ± 15.4%, PM/DM-IP: 73.6% ± 16.4%), residual volume (RV) (IIP: 70.7% ± 21.7%, PM/DM-IP: 71.5% ± 17.1%), total lung capacity (TLC) (IIP: 73.4% ± 13.6%, PM/DM-IP: 71.6% ± 13.0%), and diffusing capacity DLco (IIP: 57.5% ± 26.7%, PM/DM-IP: 46.4% ± 10.3%). Both groups achieved good responses to initial corticosteroid or immunosuppressant therapy. CONCLUSION Patients with anti-ARS antibody-positive IP have common pulmonary manifestations regardless of the presence of PM/DM.