The Roles of Neuropeptide Y in Respiratory Disease Pathogenesis via the Airway Immune Response

The lungs are very complex organs, and the respiratory system performs the dual roles of repairing tissue while protecting against infection from various environmental stimuli. Persistent external irritation disrupts the immune responses of tissues and cells in the respiratory system, ultimately leading to respiratory disease. Neuropeptide Y (NPY) is a 36-amino-acid polypeptide and a neurotransmitter that regulates homeostasis. The NPY receptor is a seven-transmembrane-domain G-protein-coupled receptor with six subtypes (Y1, Y2, Y3, Y4, Y5, and Y6). Of these receptors, Y1, Y2, Y4, and Y5 are functional in humans, and Y1 plays important roles in the immune responses of many organs, including the respiratory system. NPY and the Y1 receptor have critical roles in the pathogenesis of asthma, chronic obstructive pulmonary disease, and idiopathic pulmonary fibrosis. The effects of NPY on the airway immune response and pathogenesis differ among respiratory diseases. This review focuses on the involvement of NPY in the airway immune response and pathogenesis of various respiratory diseases

Reactive Oxygen Species and Antioxidative Defense in Chronic Obstructive Pulmonary Disease

The respiratory system is continuously exposed to endogenous and exogenous oxidants. Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways, leading to the destruction of lung parenchyma (emphysema) and declining pulmonary function. It is increasingly obvious that reactive oxygen species (ROS) and reactive nitrogen species (RNS) contribute to the progression and amplification of the inflammatory responses related to this disease. First, we described the association between cigarette smoking, the most representative exogenous oxidant, and COPD and then presented the multiple pathophysiological aspects of ROS and antioxidative defense systems in the development and progression of COPD. Second, the relationship between nitric oxide system (endothelial) dysfunction and oxidative stress has been discussed. Third, we have provided data on the use of these biomarkers in the pathogenetic mechanisms involved in COPD and its progression and presented an overview of oxidative stress biomarkers having clinical applications in respiratory medicine, including those in exhaled breath, as per recent observations. Finally, we explained the findings of recent clinical and experimental studies evaluating the efficacy of antioxidative interventions for COPD. Future breakthroughs in antioxidative therapy may provide a promising therapeutic strategy for the prevention and treatment of COPD.</p

Successful Extracorporeal Life Support for Life-threatening Hypercapnia with Bronchiolitis Obliterans after Allogeneic Hematopoietic Stem Cell Transplantation

Bronchiolitis obliterans (BO) is a disease with a poor prognosis, and a key factor that limits long-term survival after allogeneic hematopoietic stem cell transplantation (HSCT). We here report a case of a 31-year woman with acute lymphatic leukemia, which was treated by chemotherapy and HSCT, and consequently developed BO 2 years after HSCT. A non-tuberculous mycobacterial infection occurred and showed gradual exacerbation. She started taking anti-mycobacterial drugs, but lost appetite, felt tired and finally lost consciousness one month after beginning medication. Arterial blood gas revealed marked hypercapnia. Using extracorporeal life support (ECLS), the carbon dioxide concentration was reduced and her consciousness recovered. To our knowledge, this is the first case in which ECLS was successfully used for hypercapnia in a patient with BO

Churg-Strauss Syndrome with Necrosis of Toe Tips

Churg-Strauss syndrome (CSS) is a granulomatous necrotizing vasculitis of unknown etiology associated with bronchial asthma. Despite affecting small to medium-sized vessels, necrosis of the digits due to vasculitis is extremely rare. We report a case of CSS with necrosis of the toe tips. A 37-year-old woman with asthma, who had been diagnosed with CSS 2 years ago, was admitted to our hospital with an exacerbation of CSS. The patient had a high grade fever and complained of abdominal pain and numbness of the lower extremities. Blood examination revealed marked eosinophilia. The fever pattern, abdominal pain and blood eosinophilia showed improvement by combination treatment with prednisolone and cyclophosphamide. However, the color of her right toe tips changed, and necrosis finally resulted despite antithrombotic therapy. Arteriography showed narrowing of the dorsalis pedis artery and of the more peripheral arteries of her right leg. Stump plasty with negative pressure dressing therapy for the toe tips, but not amputation, was done to preserve the leg function. While numbness of the extremities remained, no recurrence of necrosis was seen. Clinicians need to be aware that rare complications of CSS, including necrosis of the digits, can occur

Experimental Pulmonary Granuloma Mimicking Sarcoidosis Induced by Propionibacterium acnes in Mice

Propionibacterium acnes has been implicated as an etiologic agent of sarcoidosis since the isolation of this bacterium from sarcoid lesions. We experimentally produced a murine pulmonary granuloma model using P. acnes with several features that simulate sarcoidosis. Mice were sensitized with heat-killed P. acnes and complete Freund's adjuvant and were subsequently challenged with heat-killed P. acnes at 2-week intervals. P. acnes-challenged mice developed epitheloid cell granulomas in the lungs. These mice showed a pulmonary immune response characterized by an increased number of T-lymphocytes, especially CD4 cells, and the ratio of CD4/CD8 in bronchoalveolar lavage (BAL) fluid also increased. Furthermore, significant elevations in both angiotensin-converting enzyme (ACE) serum levels and antibody titers against P. acnes were observed. Mice sensitized with P. acnes without complete Freund's adjuvant were capable of forming pulmonary granulomas, which appeared to be caused by indigenous P. acnes. The genome of P. acnes was found in the lungs, BAL cells, hilar lymph nodes, liver, and spleen in non-sensitized mice, which were thought to be germ-free. These results suggest that the immune response against indigenous P. acnes may play an important role in the pathogenesis of granuloma formation in a murine model.</p

Dramatic Response to Tezepelumab as an Initial Biologic Agent for Refractory Asthma Associated with Type 2 and Non-type 2 Traits

A 74-year-old Japanese woman presented with a 45-year history of refractory asthma. She had been treated with inhaled corticosteroids, a long-acting β2-agonist, and a long-acting muscarinic antagonist for 6 months. She also had a repeated viral infection. Her condition had been characterized as a refractory asthma associated with type 2 and non-type 2 traits. We began treatment with tezepelumab. The control of the patient’s asthma symptoms and quality of life improved greatly within 1 month (changes in eosinophil count from 748 to 96 /μL, in FeNO from 32 to 17 ppb, in the Asthma Quality of Life Questionnaire score from 3.59 to 6.68, and in the Asthma Control Test score from 13 to 23). Tezepelumab was effective as an initial biologic agent for a patient with refractory asthma associated with type 2 and non-type 2 traits

Diffuse alveolar hemorrhage with chronic thyroiditis in an advanced-age adult

AbstractIdiopathic pulmonary hemosiderosis (IPH) is one of the rare causes of diffuse alveolar hemorrhage (DAH), and usually occurs in children. The mechanism underlying this disease development has not been defined. During the acute phase, death due to massive alveolar hemorrhage and subsequent severe respiratory failure with multiple organ failure often occurs. We report a case of IPH which occurred in an advanced-aged adult during following thyroidectomy for chronic thyroiditis. Following surgery this 83-year-old male developed acute onset dyspnea and pulmonary hemorrhage. In a search for underlying causes, no disorders were found and the only finding was the presence of anti-thyroid antibody. Systemic corticosteroid therapy was effective and he fully recovered. To our knowledge, this is the second documentation of IPH in association with chronic thyroiditis

Increased Serum KL-6 Levels Induced by Pulmonary Mycobacterium Avium Complex Infection in a Patient with RA-associated Lung Disease

KL-6 is a glycoprotein found predominantly on type II pneumocytes and alveolar macrophages, and often shows increased serum levels in patients with interstitial pneumonia. We report a case of mycobacterium avium complex (MAC) infection whose disease activity was correlated with KL-6 levels in serum. During treatment of rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) with prednisolone, chest image findings improved in association with decreased KL-6 levels. Following tapering of prednisolone, chest image findings deteriorated again as levels of KL-6 increased, suggesting recurrence of RA-ILD. Bronchoscopic examination revealed active MAC infection. Treatment of MAC infection not only improved chest image findings but also decreased KL-6 levels in serum, suggesting that KL-6 was increased by active MAC infection by itself, not by recurrence of RA-ILD. To the best of our knowledge, this is the first documentation of KL-6 elevation in serum in association with active MAC infection

Successful Re-administration of Osimertinib in Osimertinib-induced Interstitial Lung Disease with an Organizing Pneumonia Pattern: A Case Report and Literature Review

Osimertinib is the standard therapy for epidermal-growth-factor-receptor (EGFR)-mutant lung cancers. We herein report a case of osimertinib-induced interstitial lung disease (OsiILD) with an organizing pneumonia (OP) pattern and provide a literature-based review. Six months after osimertinib administration, a 75-year-old woman with right pleural carcinomatosis developed ILD with an OP pattern. After salvage chemotherapy, osimertinib with corticosteroid was successfully re-administered. A literature review suggested that 1) OsiILD with an OP pattern was rare but should be recognized, and 2) re-administration of osimertinib in OsiILD was successful in select patients. A criterion that determines whether a patient would benefit from re-administration is warranted

A case of axillary lymphadenitis caused by Mycobacterium intracellulare in an immunocompetent patient

Axillary lymphadenitis caused by non-tuberculous mycobacteria is rare and has been reported in immunocompromised hosts. Herein, we report the case of a 67-year-old man without immunodeficiency who developed right axillary lymphadenitis caused by Mycobacterium intracellulare and showed a small nodular shadow in the left pulmonary apex. Biopsy of the right axillary lymph node revealed several epithelioid granulomas, and the culture of the lymph node aspirate yielded Mycobacterium intracellulare. The lymph node lesion and left lung apex shadow resolved spontaneously after careful outpatient monitoring. This case suggests that axillary lymphadenitis could be caused by Mycobacterium intracellulare in an immunocompetent patient