Survival and acute exacerbation for patients with idiopathic pulmonary fibrosis (IPF) or non-IPF idiopathic interstitial pneumonias: 5-year follow-up analysis of a prospective multi-institutional patient registry.

OBJECTIVE: Few prospective cohort studies with relatively large numbers of patients with non-idiopathic pulmonary fibrosis (non-IPF) of idiopathic interstitial pneumonia (IIP) have been described. We aimed to assess disease progression and cause of death for patients with non-IPF IIPs or IPF under real-life conditions. METHODS: Data were analysed for a prospective multi-institutional cohort of 528 IIP patients enrolled in Japan between September 2013 and April 2016. Diagnosis of IPF versus non-IPF IIPs was based on central multidisciplinary discussion, and follow-up surveillance was performed for up to 5 years after patient registration. Survival and acute exacerbation (AE) were assessed. RESULTS: IPF was the most common diagnosis (58.0%), followed by unclassifiable IIPs (35.8%) and others (6.2%). The 5-year survival rate for non-IPF IIP and IPF groups was 72.8% and 53.7%, respectively, with chronic respiratory failure being the primary cause of death in both groups. AE was the second most common cause of death for both non-IPF IIP (24.1%) and IPF (23.5%) patients. The cumulative incidence of AE did not differ significantly between the two groups (p=0.36), with a 1-year incidence rate of 7.4% and 9.0% in non-IPF IIP and IPF patients, respectively. We found that 30.2% and 39.4% of non-IPF IIP and IPF patients, respectively, who experienced AE died within 3 months after an AE event, whereas 55.8% and 66.7% of such patients, respectively, died within 5 years after registration. CONCLUSION: Closer monitoring of disease progression and palliative care interventions after AE are important for non-IPF IIP patients as well as for IPF patients.

Early Recognition and Treatment of Relapsing Polychondritis.

We describe the case of a 60-year-old Japanese man with relapsing polychondritis (RP). The patient was referred to Hamanomachi Hospital due to mild elevation of C-reactive protein and mild anemia on medical checkup without any symptoms. Body CT imaging showed thickened tracheal and bronchial walls with no active lesions in the lung. Precise physical examination revealed swelling in both ears. Bronchoscopy revealed redness and swelling of the tracheal and bronchial mucosa in the membranous lesion. Histologic examination of the bronchial biopsy showed inflammatory cell infiltration in the sub-mucosa with no vasculitis. Serum anti-type 2 collagen antibodies were found to be positive (33.9 EU/mL). Corticosteroid treatment improved his tracheochondritis. It is challenging to diagnose RP in the early stage due to its rarity and nonspecific symptoms. Airway involvement in RP is irreversible and the major cause of morbidity and mortality; hence, early recognition of airway involvement and treatment is warranted.

Idiopathic Pulmonary Fibrosis Complicated by Adenocarcinoma and Organizing Pneumonia.

We describe a case of a 77-year-old male with idiopathic pulmonary fibrosis (IPF) complicated by lung adenocarcinoma and organizing pneumonia (OP). On initial examination, physical examination revealed fine crackles in both sides of his chest. There were no physical findings suggestive of collagen disease. Blood tests showed no elevation of C-reactive protein, and lactate dehydrogenase and Krebs von den Lungen-6 (KL-6) were within normal limits. A high-resolution CT (HRCT) of the chest showed multiple ground-glass opacities (GGOs) in both lungs, with consolidation and traction bronchiectasis in the left lower lobe. Although a bronchoscopy was performed, no diagnosis could be made. Bronchoalveolar lavage showed elevated lymphocytes, and treatment with prednisolone was started for the possibility of OP. Subsequent chest X-ray and chest CT showed worsening of the shadows over time, and shortness of breath on exertion progressed. Surgical lung biopsy revealed IPF complicated by adenocarcinoma and OP. Although the patient was treated with pemetrexed and carboplatin combination therapy, respiratory failure progressed, and palliative care was decided. There is no report of IPF complicated by adenocarcinoma and OP, and early surgical lung biopsy may be important for diagnosis.

Lenvatinib for poorly differentiated carcinoma of the anterior mediastinum.

We describe a Case of a 74-year-old Japanese man with poorly differentiated carcinoma of the anterior mediastinum. The patient underwent anterior mediastinal tumor resection through median sternotomy. The tumor, 7.0 × 5.0 cm, had invaded surrounding tissues (pericardium, right lung, right and left brachiocephalic veins, and superior vena cava). Complete resection of the tumor was not performed. One month after the operation, the patient developed multiple pulmonary metastases, right pleural dissemination, and carcinomatous pleurisy. He was treated with lenvatinib, a novel multi-kinase inhibitor, to which the metastasis responded favorably. This case reports for the first time the clinical usefulness of lenvatinib for poorly differentiated carcinoma of the anterior mediastinum. Management of side effects by several methods, including suspending use of medication on weekends (called a weekends-off strategy), is another strong argument to continue lenvatinib administration.

Pulmonary amyloidosis complicated with pulmonary hemosiderosis, diagnosed with bronchoscopy.

We describe a case of an 82-year-old Japanese woman with pulmonary amyloidosis and hemosiderosis associated with multiple myeloma. She had a background of end-stage renal failure of unknown etiology and had been on maintenance dialysis for 2 years. She complained of exertional dyspnea for four months. High-resolution CT of the chest revealed diffuse ground-glass opacities with mosaic attenuation, consolidation in the left lingular lobe, and wedge-shaped, subpleural nodules in the bilateral lower lobes. A transbronchial lung biopsy of the left lingular lobe showed deposition of amorphous, eosinophilic amyloid at the smooth muscle layer of bronchial tissue, with a positive Congo red staining signal in polarized light. Bronchoalveolar lavage fluid was brownish-yellow, and numerous hemosiderin-laden macrophages were detected with Berlin blue staining. From these findings, a diagnosis of pulmonary amyloidosis complicated with pulmonary hemosiderosis was made. Further work-up led to a diagnosis of multiple myeloma. Pulmonary amyloidosis complicated with pulmonary hemosiderosis is a rare disorder and may be underdiagnosed. Physical examination, such as the appearance of the tongue, can assist the diagnosis of systemic amyloidosis. Use of bronchoscopy allows physicians make an early diagnosis of pulmonary amyloidosis that is minimally invasive.

A Rare Case of Pembrolizumab-Induced Dermatomyositis in a Patient with Cancer of Unknown Primary Origin.

BACKGROUND Pembrolizumab is a humanized monoclonal antibody against programmed cell death-1 protein. Pembrolizumab sometimes causes immune-related adverse events (irAEs). Dermatomyositis is a rare irAE of immune checkpoint inhibitors. The presentation is usually acute, and symptoms include edema with erythema of the eyelids, erythema of the forehead, and muscle weakness in both thighs. CASE REPORT Here we report a case of pembrolizumab-induced dermatomyositis in a 71-year-old Japanese woman with cancer of unknown primary origin, who experienced a high fever and had difficulty walking after her sixth course of pembrolizumab. General physical examination revealed edema with a heliotrope rash, V-neck signs, and nonspecific erythema of the forehead. Laboratory evaluation revealed that myogenic enzymes were within normal ranges. Autoantibody tests revealed that antinuclear antibodies were negative, and autoantibodies related to myositis and anti-acetylcholine receptor antibodies were also negative. A magnetic resonance imaging scan of the thighs revealed signal abnormalities in the left lateral and distal vastus medialis muscle. The patient was treated with corticosteroids, subsequently followed by intravenous immunoglobulin therapy, which led to an improvement of the symptoms. CONCLUSIONS Pembrolizumab-induced dermatomyositis is rare. Corticosteroids have been administered in many cases, and this case also suggests the efficacy of intravenous immunoglobulin therapy in treating immune checkpoint inhibitor-related dermatomyositis. This case highlights practical management of pembrolizumab-induced dermatomyositis.

A Case of Drug-Induced Interstitial Lung Disease Caused by Epirubicin and Cyclophosphamide Therapy Before Breast Cancer Surgery.

We report a case of drug-induced interstitial lung disease (ILD) caused by epirubicin and cyclophosphamide (EC) therapy in a patient with breast cancer. The patient suffered from a dry cough, fever, and exertional dyspnea after two courses of EC therapy. Antibiotic treatment did not improve her symptoms. Chest CT images revealed diffuse, ground-glass opacities and mild interlobular septal thickening in both lungs, a pattern suggesting a hypersensitivity pneumonitis. Bronchoalveolar lavage fluid analysis revealed lymphocytosis with no evidence of infection nor malignancy. Corticosteroid therapy was initiated, which led to a rapid resolution of ILD. To date, there has been only one case report regarding drug-induced ILD caused by EC therapy. This case report could increase awareness of chemotherapy-induced pneumonitis.

Durable response to nivolumab in a lung adenocarcinoma patient with idiopathic pulmonary fibrosis.

The efficacy and safety of immune-checkpoint inhibitors in non-small cell lung cancer patients with idiopathic pulmonary fibrosis (IPF) remain unknown. Herein, we describe the case of a 62-year-old man with multiple pleural tumors and carcinomatous pleurisy. High-resolution computed tomography indicated usual interstitial pneumonia, and a respiratory function test revealed a restrictive disorder and decreased diffusion capacity. He was diagnosed with lung adenocarcinoma and IPF. After failure of initial chemotherapy, he was treated with nivolumab and achieved a complete response without any sign of exacerbation of IPF. The response to nivolumab has persisted for > 1 year. This is the first report of a non-small cell lung cancer patient with IPF who has been treated with immune-checkpoint inhibitors for such a long period and achieved a sustained response.

Probucol attenuates hyperoxia-induced lung injury in mice.

Hyperoxic lung injury is pathologically characterized by alveolar edema, interlobular septal edema, hyaline membrane disease, lung inflammation, and alveolar hemorrhage. Although the precise mechanism by which hyperoxia causes lung injury is not well defined, oxidative stress, epithelial cell death, and proinflammatory cytokines are thought to be involved. Probucol-a commercially available drug for treating hypercholesterolemia-has been suggested to have antioxidant and antiapoptotic effects. This study aimed to assess whether probucol could attenuate hyperoxic lung injury in mice. Mice were exposed to 95% O2 for 72 h, with or without pre-treatment with 130 µg/kg probucol intratracheally. Probucol treatment significantly decreased both the number of inflammatory cells in the bronchoalveolar lavage fluid and the degree of lung injury in hyperoxia-exposed mice. Probucol treatment reduced the number of cells positive for 8-hydroxyl-2'-deoxyguanosine or terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and suppressed NF-κB activation, Bax expression, and caspase-9 activation in lung tissues from hyperoxia-exposed mice. These results suggest that probucol can reduce oxidative DNA damage, apoptotic cell death, and inflammation in lung tissues. Intratracheal administration of probucol may be a novel treatment for lung diseases induced by oxidative stress, such as hyperoxic lung injury and acute respiratory distress syndrome.

Amphiregulin suppresses epithelial cell apoptosis in lipopolysaccharide-induced lung injury in mice.

BACKGROUND AND OBJECTIVE: As a member of the epidermal growth factor family, amphiregulin contributes to the regulation of cell proliferation. Amphiregulin was reported to be upregulated in damaged lung tissues in patients with chronic obstructive pulmonary disease and asthma and in lung epithelial cells in a ventilator-associated lung injury model. In this study, we investigated the effect of amphiregulin on lipopolysaccharide (LPS)-induced acute lung injury in mice. METHODS: Acute lung injury was induced by intranasal instillation of LPS in female C57BL/6 mice, and the mice were given intraperitoneal injections of recombinant amphiregulin or phosphate-buffered saline 6 and 0.5 h before and 3 h after LPS instillation. The effect of amphiregulin on apoptosis and apoptotic pathways in a murine lung alveolar type II epithelial cell line (LA-4 cells) were examined using flow cytometry and western blotting, respectively. RESULTS: Recombinant amphiregulin suppressed epithelial cell apoptosis in LPS-induced lung injury in mice. Western blotting revealed that amphiregulin suppressed epithelial cell apoptosis by inhibiting caspase-8 activity. CONCLUSION: Amphiregulin signaling may be a therapeutic target for LPS-induced lung injury treatment through its prevention of epithelial cell apoptosis.

A case of diffuse large B-cell lymphoma of the lung demonstrating diffuse ground-glass shadows.

We report a case of 77-year-old woman suffering from breathlessness on exertion and dry cough. Chest computed tomography (CT) showed diffuse ground-glass shadows. A video-assisted thoracoscopic lung biopsy resulted in the diagnosis of diffuse large B-cell lymphoma (DLBCL). Gene rearrangement analysis using polymerase chain reaction (PCR) technique was performed on the cells in bronchoalveolar lavage (BAL) fluid, and showed the clonality of the immunoglobulin heavy chain (IgH) gene, supporting the diagnosis. DLBCL should be considered in the differential diagnosis of diffuse ground-glass shadows in the chest CT, and gene rearrangement analysis may have an impact on the diagnosis of pulmonary DLBCL.

EGFR tyrosine kinase inhibition worsens acute lung injury in mice with repairing airway epithelium.

RATIONALE: Epidermal growth factor receptor (EGFR) and its ligands play important roles in the regeneration of damaged epithelium and proliferation of various epithelial tumors. Although the EGFR-tyrosine kinase inhibitor gefitinib is effective against advanced non-small cell lung cancer with EGFR mutations, some patients treated with this agent develop severe acute interstitial pneumonia. Characteristics of patients who develop interstitial pneumonia include older age, smoking history, and preexisting interstitial pneumonia suggesting a connection between airway injury and alveolar dysfunction. OBJECTIVES: The purpose of this study was to investigate the effects of gefitinib on airway repair after injury. METHODS: C57BL/6J mice received intraperitoneally naphthalene at Day 0. Gefitinib (20, 90, or 200 mg/kg) was given daily at Days--1 to 13 after naphthalene administration. Bronchoalveolar lavage fluid and lung tissue were obtained at Days 7 and 14. Terminal bronchial epithelial cells from Days 7 and 14 were retrieved with laser capture microdissection, and gene expression analyzed using microarray. MEASUREMENTS AND MAIN RESULTS: Gefitinib treatment after naphthalene prolonged neutrophil sequestration and worsened acute lung injury. We found 17 genes with more than a threefold increase in bronchiolar epithelial cells from mice treated with 200 mg/kg of gefitinib after naphthalene at Day 14 compared with those treated with naphthalene alone. Up-regulated genes included S100A8, S100A6, and StefinA3. These genes are known to participate in neutrophil sequestration, acute inflammation, and airway remodeling. CONCLUSIONS: EGFR inhibition in repairing airway epithelial cells modulated significant expression of genes involved in the airway microenvironment, prolonged inflammation, and potentiated acute lung injury.

[A case of interstitial pneumonia with smoldering adult T-cell leukemia].

A 66-year-old woman was admitted because of dry cough and dyspnea. Computed tomography showed ground-glass opacities and traction bronchiectasis in both lung fields. Then, ATL cells appeared in her peripheral blood, and the number of lymphocytes in BALF increased. Inverse PCR for HTLV-1 clonality of the peripheral blood revealed a polyclonal pattern, and she was given a diagnosis of smoldering adult T-cell leukemia. Using BALF flow cytometry, both CD4- and CD25-positive cells accounted for only 0.8%. Secondary interstitial pneumonia was diagnosed and we started therapy with prednisolone and cyclophosphamide. BALF flow cytometry may be useful in the differential diagnosis of ATL lung lesions.

Amphiregulin attenuates bleomycin-induced pneumopathy in mice.

Amphiregulin, an EGF receptor (EGFR) ligand, is essential for epithelial development in various organs. A recent report suggested that amphiregulin acts as a protective factor in a liver injury model. Little is known about the roles of amphiregulin in lung injury and pulmonary fibrosis. The purpose of the present study was to investigate the role of amphiregulin in an experimental model of bleomycin-induced pneumopathy in mice. C57BL/6 mice were administered a bleomycin hydrochloride solution intratracheally. Recombinant human amphiregulin was injected intraperitoneally at 6, 8, 10, and 12 days after the bleomycin instillation. The grades of inflammation and fibrosis were assessed histologically and biochemically, and the numbers of apoptotic cells were counted after TdT-mediated dUTP nick end labeling (TUNEL) staining in the lung tissues. We also examined downstream survival signals of EGFR, namely phosphorylated Akt and phosphorylated Erk, in lung tissues by Western blotting analysis and immunohistochemistry. Expression of intrinsic amphiregulin was increased in murine lung tissues after bleomycin instillation. Administration of recombinant amphiregulin improved the survival rate and suppressed the degrees of inflammation and fibrosis and the number of TUNEL-positive cells in lung tissues. Amphiregulin treatment enhanced the activation of Akt and Erk in lung epithelial cells. Amphiregulin may play a protective role in bleomycin-induced pneumopathy in mice, probably through the activation of survival signals. Administration of amphiregulin may be a novel therapeutic strategy against lung injury and fibrosis.

Recombinant human erythropoietin reduces epithelial cell apoptosis and attenuates bleomycin-induced pneumonitis in mice.

BACKGROUND AND OBJECTIVE: Erythropoietin (EPO) has recently been demonstrated to have a tissue protective role by acting as an anti-apoptotic agent in various tissues, such as brain, spinal cord, heart and kidney. The purpose of this study was to determine whether human recombinant EPO reduces epithelial cell apoptosis and attenuates bleomycin-induced pneumonitis in mice. METHODS: Bleomycin was instilled intratracheally into C57BL/6 mice. Recombinant human EPO or saline was injected intraperitoneally, daily from day 5 to day 13 after bleomycin instillation. RESULTS: EPO receptor was expressed in bronchiolar and alveolar type II cells. At 14 days after instillation, the number of terminal uridine deoxynucleotidyl transferase nick end-labelled positive cells in the lung was decreased, and the histological degree of inflammation and fibrosis was attenuated in mice injected with EPO compared with controls. Expression of phosphorylated Akt and Erk, which are thought to mediate the survival signalling pathway induced by EPO, tended to be increased in lung tissues from mice treated with EPO compared with those from mice treated with saline after bleomycin instillation. CONCLUSIONS: As it is likely that EPO protects epithelial cells from injury and apoptosis, EPO administration could be a potential therapeutic strategy for the prevention of lung injury.

The role of high mobility group box1 in pulmonary fibrosis.

High mobility group box1 protein (HMGB1) was originally discovered as a nuclear binding protein, and is known to play an important role in acute lung injury. However, the role of HMGB1 in pulmonary fibrosis has not been addressed. Therefore, we measured the HMGB1 levels in serum and bronchoalveolar lavage fluids (BALF) from patients with idiopathic pulmonary fibrosis (IPF), nonspecific interstitial pneumonia, interstitial pneumonia associated with collagen vascular diseases, and hypersensitivity pneumonitis (HP) by enzyme-linked immunosorbent assay. We also assessed the HMGB1 expression in bleomycin-induced pulmonary fibrosis in mice, and examined the effect of anti-HMGB1 antibody and ethyl pyluvate, which inhibits the HMGB1 secretion from alveolar macrophages. In addition, we examined the effect of HMGB1 on fibroblast proliferation, apoptosis, and collagen synthesis in vitro. Serum HMGB1 levels were not significantly increased in interstitial lung diseases compared with control subjects. BALF HMGB1 levels were significantly increased in IPF and HP compared with control subjects. HMGB1 protein was predominantly detected in inflammatory cells and hyperplasic epithelial cells in IPF. In bleomycin-induced pulmonary fibrosis in mice, HMGB1 protein was predominantly up-regulated in bronchiolar epithelial cells at early phase and in alveolar epithelial and inflammatory cells in fibrotic lesions at later phase. Intraperitoneal injection of anti-HMGB1 antibody or ethyl pyluvate significantly attenuated lung inflammation and fibrosis in this model. HMGB1 significantly induced proliferation, but not apoptosis or collagen synthesis on cultured fibroblasts. HMGB1 may be a promising target against pulmonary fibrosis as well as acute lung injury.

Dual-immunohistochemistry provides little evidence for epithelial-mesenchymal transition in pulmonary fibrosis.

Epithelial-mesenchymal transition (EMT) has been considered to be involved in organ fibrogenesis. However, there is few direct evidence of this process in the pathophysiology of pulmonary fibrosis in vivo. Therefore, we tried to verify the involvement of this process in the development of pulmonary fibrosis. Since the co-expressions of epithelial and mesenchymal markers are thought to be a marker of EMT, we performed dual-immuunohistochemistry to assess the co-expressions of these proteins in lung tissues from bleomycin-induced pulmonary fibrosis in mice, and from patients with idiopathic pulmonary fibrosis, and nonspecific interstitial pneumonia. Double positive cells for epithelial markers including E-cadherin, T1alpha, or aquaporin 5, and a mesenchymal markers alpha-smooth muscle actin or vimentin were not found in bleomycin-induced pulmonary fibrosis in mice. Double positive cells for E-cadherin, ICAM-1, LEA, CD44v9, or SP-A and alpha-smooth muscle actin or vimentin were not found in lung tissues from normal lung parenchyma, idiopathic pulmonary fibrosis and nonspecific interstitial pneumonia. These results offer at least two possibilities. One is that EMT does not occur in IPF or bleomycin-induced pulmonary fibrosis in mice. Another is that EMT may occur in pulmonary fibrosis but the time during this transition in which cells express detectable levels of epithelial and mesenchymal markers is too small to be detected by double immunohistochemistry.

Gene transfer of soluble transforming growth factor type II receptor by in vivo electroporation attenuates lung injury and fibrosis.

BACKGROUND: Transforming growth factor-beta1 (TGF-beta1) has the potential to induce acute inflammation and apoptosis in lung epithelial cells and plays a central role in subsequent fibrosis. AIMS: To examine a new anti-TGF-beta1 therapy against lung injury and fibrosis, which comprises the transfection of soluble TGF type II receptor (sTGFRII) gene into skeletal muscles by in vivo electroporation. METHODS: Soluble TGFRII was detectable between 1 and 14 days in the serum and significantly increased between 3 and 10 days after gene transfer into muscles. Based on these findings, the sTGFRII gene was injected at 3 days before or 4 days after the bleomycin instillation in order to examine the significance of TGF-beta1 on the early inflammatory phase (day 0 to day 7) or the fibrotic phase (day 7 to day 14) in this model. RESULTS: Transfection of sTGFRII gene at 3 days before or 4 days after bleomycin instillation significantly attenuated apoptosis, injury, and fibrosis at 7 or 14 days, respectively. This method does not require the use of viral vector or neutralising antibody, and it is therefore possible to avoid problems regarding the pathogenicity of the viral vector or immunocomplex. CONCLUSIONS: This novel anti-TGF-beta1 strategy may have clinical application in the treatment of lung injury and fibrosis.

Anti-vascular endothelial growth factor gene therapy attenuates lung injury and fibrosis in mice.

Vascular endothelial growth factor (VEGF) is an angiogenesis factor with proinflammatory roles. Flt-1 is one of the specific receptors for VEGF, and soluble flt-1 (sflt-1) binds to VEGF and competitively inhibits it from binding to the receptors. We examined the role of VEGF in the pathophysiology of bleomycin-induced pneumopathy in mice, using a new therapeutic strategy that comprises transfection of the sflt-1 gene into skeletal muscles as a biofactory for anti-VEGF therapy. The serum levels of sflt-1 were significantly increased at 3-14 days after the gene transfer. Transfection of the sflt-1 gene at 3 days before or 7 days after the intratracheal instillation of bleomycin decreased the number of inflammatory cells, the protein concentration in the bronchoalveolar lavage fluid and with von Willebrand factor expression at 14 days. Transfection of the sflt-1 gene also attenuated pulmonary fibrosis and apoptosis at 14 days. Since the inflammatory cell infiltration begins at 3 days and is followed by interstitial fibrosis, it is likely that VEGF has important roles as a proinflammatory, a permeability-inducing, and an angiogenesis factor not only in the early inflammatory phase but also in the late fibrotic phase. Furthermore, this method may be beneficial for treating lung injury and fibrosis from the viewpoint of clinical application, since it does not require the use of a viral vector or neutralizing Ab.

Serum CC-10 in inflammatory lung diseases.

BACKGROUND: Although Clara cell secretory protein (CC-10) has been ascribed an anti-inflammatory role in lung diseases, its precise role remains unclear. OBJECTIVE: To further our understanding of the role of CC-10 in inflammatory lung diseases, CC-10 protein levels were measured. METHODS: Sera or bronchoalveolar lavage (BAL) fluids were collected from patients with different inflammatory lung diseases including bronchial asthma, chronic obstructive lung disease (COPD), sarcoidosis, idiopathic interstitial pneumonia (IIP), chronic eosinophilic pneumonia (CEP), pneumonia and lung cancer. Serum CC-10 concentrations were measured by enzyme-linked immunosorbent assay using urinary protein-1 antibody. Then, the relationships between CC-10 concentrations and lung diseases were investigated. Immunohistochemistry was performed using lung biopsy samples. RESULTS: Increased serum CC-10 levels were recognized in IIP patients, while CC-10 levels were decreased in bronchial asthma patients and CEP patients. Immunohistochemistry revealed an aberrant expression in areas of fibrosis in IIP patients. Serum CC-10 concentrations were not associated with severity among IIP, COPD, and sarcoidosis. In contrast, serum CC-10 concentrations were correlated with FEV(1)/FVC in bronchial asthma patients. CONCLUSIONS: Although the number of patients was quite limited, these data provide new insights into the role of CC-10 in lung diseases, and the possibility that the CC-10 concentration in serum could be a new marker indicating the severity of bronchial asthma.