Expectations of respiratory physicians from psychologists in palliative care for patients with non-cancer respiratory diseases.

BACKGROUND: Psychological symptoms are common in patients with non-malignant respiratory disease (NMRD). Psychologists can likely play a role in NMRD palliative care. We aimed to explore the expectations of respiratory physicians from psychologists in NMRD palliative care. METHODS: An ad hoc questionnaire was developed based on a free-descriptive questionnaire survey among respiratory physicians from four hospitals in Japan. Using this questionnaire, we surveyed respiratory physicians from eight hospitals in Japan and assessed their expectations of psychologists' support and outcomes. Expectations were compared between physicians with and without experience of working with psychologists. RESULTS: The quantitative questionnaire was completed by 129 physicians. Data analysis from 108 participants revealed that the highly expected support included "getting early information on patients' psychological distress" (97.2%) and "counseling family members regarding anxiety caused by changes in patient's condition" (96.3%). Physicians also expected "relief in patient's psychological distress" (96.3%) and "providing the psychological support that families need" (95.4%) from psychologists. Compared to physicians with experience of working with psychologists, those without expected more in terms of "giving specific advice on the way of communication and psychological support" (p = 0.035) and "providing psychological support for difficult-to-handle patients and families on behalf of other medical staff" (p = 0.036). CONCLUSIONS: Respiratory physicians may expect relief of psychological distress experienced by patients and their families from psychologists by getting information about their distress and providing psychological support. These results may be useful for psychologists to provide palliative care for patients with NMRD in collaboration with respiratory physicians.

Prompt Reduction in CRP, IL-6, IFN-γ, IP-10, and MCP-1 and a Relatively Low Basal Ratio of Ferritin/CRP Is Possibly Associated With the Efficacy of Tocilizumab Monotherapy in Severely to Critically Ill Patients With COVID-19.

Background and Aim: Tocilizumab, a humanized anti-IL-6 receptor antibody, has been used to treat severely to critically ill patients with COVID-19. A living systematic review with meta-analysis of recent RCTs indicates that the combination therapy of corticosteroids and tocilizumab produce better outcomes, while previous observational studies suggest that tocilizumab monotherapy is beneficial for substantial numbers of patients. However, what patients could respond to tocilizumab monotherapy remained unknown. Methods: In this retrospective study we evaluated the effects of tocilizumab monotherapy on the clinical characteristics, serum biomediator levels, viral elimination, and specific IgG antibody induction in 13 severely to critically ill patients and compared with those of dexamethasone monotherapy and dexamethasone plus tocilizumab. Results: A single tocilizumab administration led to a rapid improvement in clinical characteristics, inflammatory findings, and oxygen supply in 7 of 11 patients with severe COVID-19, and could recover from mechanical ventilation management (MVM) in 2 patients with critically ill COVID-19. Four patients exhibited rapidly worsening even after tocilizumab administration and required MVM and additional methylprednisolone treatment. Tocilizumab did not delay viral elimination or inhibit IgG production specific for the virus, whereas dexamethasone inhibited IgG induction. A multiplex cytokine array system revealed a significant increase in the serum expression of 54 out of 80 biomediators in patients with COVID-19 compared with that in healthy controls. Compared with those who promptly recovered in response to tocilizumab, patients requiring MVM showed a significantly higher ratio of basal level of ferritin/CRP and a persistent increase in the levels of CRP and specific cytokines and chemokines including IL-6, IFN-γ, IP-10, and MCP-1. The basal high ratio of ferritin/CRP was also associated with clinical deterioration even in patients treated with dexamethasone and tocilizumab. Conclusion: Tocilizumab as monotherapy has substantial beneficial effects in some patients with severe COVID-19, who showed a relatively low level of the ratio of ferritin/CRP and prompt reduction in CRP, IL-6, IFN-γ, IP-10, and MCP-1. The high ratio of ferritin/CRP is associated with rapid worsening of pneumonia. Further evaluation is warranted to clarify whether tocilizumab monotherapy or its combination with corticosteroid is preferred for severely to critically ill patients with COVID-19.

Prognostic significance of serum cytokines during acute exacerbation of idiopathic interstitial pneumonias treated with thrombomodulin.

BACKGROUND: Acute exacerbation (AE) has been reported to herald a poor prognosis in idiopathic pulmonary fibrosis and is now thought to do so in idiopathic interstitial pneumonias (IIPs). However, the pathophysiology of AE-IIPs is not sufficiently understood. In our previously reported SETUP trial, we found better survival in patients with AE-IIPs treated with corticosteroids and thrombomodulin than in those treated with corticosteroids alone. In that study, we collected serum samples to evaluate changes in cytokine levels and retrospectively examined the prognostic significance and pathophysiological role of serum cytokines in patients with AE-IIPs. METHODS: This study included 28 patients from the SETUP trial for whom serial serum samples had been prospectively obtained. AE-IIPs were diagnosed using the Japanese Respiratory Society criteria. All patients were treated with intravenous thrombomodulin and corticosteroids from 2014 to 2016. Serum levels of 27 cytokines were measured using Bio-Plex. The high-resolution CT pattern at the time of diagnosis of AE was classified as diffuse or non-diffuse. RESULTS: Univariate analysis revealed that higher serum levels of interleukin (IL)-2, IL-7, IL-9, IL-12, IL13, basic fibroblast growth factor, granulocyte-macrophage colony-stimulating factor, interferon-γ inducible protein-10, platelet-derived growth factor and regulated on activation, normal T cell expressed and secreted (RANTES) at AE were significant predictors of 90-day survival. The HRCT pattern was also a significant clinical predictor of 90-day survival. Multivariate analysis with stepwise selection identified a higher serum RANTES level at AE to be a significant predictor of 90-day survival, including after adjustment for HRCT pattern. Multivariate analysis with stepwise selection suggested that a marked increase in the serum IL-10 level on day 8 could predict 90-day mortality. CONCLUSIONS: A higher serum RANTES level at AE the time of diagnosis predicted a good survival outcome, and an elevated serum IL-10 level on day 8 predicted a poor survival outcome. TRIAL REGISTRATION NUMBER: UMIN000014969.

Scoring system for identifying Japanese patients with COVID-19 at risk of requiring oxygen supply: A retrospective single-center study.

INTRODUCTION: Japan is facing the threat of medical system collapse due to the rapid spread of coronavirus disease 2019 (COVID-19). The present scoring system may help assess disease severity and oxygen supply requirements in COVID-19 patients. METHODS: Data on patient characteristics at baseline and throughout hospitalization for COVID-19 were extracted from medical records. Disease severity was dichotomized into two categories without or with oxygen supply as asymptomatic, mild, and moderate illness (AMMI), and severe and critical illness (CSI). The AMMI and CSI groups were compared. Predictors of disease severity, previously identified in the outpatient setting, were included in multivariable logistic regression analysis; the obtained coefficients were converted to integers and assigned a score. RESULTS: A total of 206 patients diagnosed with COVID-19 were included in this study. Correlation between COVID-19 severity and medical information was examined by comparing AMMI and CSI. Age, hemodialysis, and C-reactive protein (CRP) levels were candidate predictors of the need for oxygen supply in patients with COVID-19. Coefficients associated with age, hemodialysis, and CRP were as follows: 1 × age (in years, coded as 0 for values of <50, and as 1 for values of ≥50) + 1 × hemodialysis (coded as 0 for "no", and as 1 for "yes") + 1 × CRP (in mg/dL, coded as 0 for values of <1.0, and as 1 for values of ≥1.0). Patients with scores of ≥2 points required oxygen supply (sensitivity, 68.4%; specificity, 79.0%) CONCLUSION: The present model can help predict disease severity and oxygen requirements in COVID-19 patients in Japan.

Clinical COVID-19 diagnostic methods: Comparison of reverse transcription loop-mediated isothermal amplification (RT-LAMP) and quantitative RT-PCR (qRT-PCR).

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is a major public health concern. Accurate and rapid diagnosis of COVID-19 is critical for disease control. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) is a nucleic acid amplification assay similar to reverse transcription-polymerase chain reaction (RT-PCR), the former being a simple, low cost, and rapid method. OBJECTIVES: This study aimed to compare the RT-LAMP assay with RT-PCR using the Loopamp™ SARS-CoV-2 Detection Kit. STUDY DESIGN: One hundred and fifty-one nasopharyngeal swab and 88 sputum samples obtained from individuals with suspected or confirmed COVID-19 were examined. RESULTS: RT-LAMP had high specificity (98.5 % (95 % CI: 96.9-100 %)), sensitivity (87.0 % (95 % CI: 82.8-91.3 %)), positive predictive value (97.9 % (95 % CI: 96.1-99.7 %)), negative predictive value (90.2 % (95 % CI: 86.4-94.0 %)), and concordance rate (93.3 % (95 % CI: 90.1-96.5 %)). Nasopharyngeal and sputum samples positive in RT-LAMP contained as few as 10.2 and 23.4 copies per 10 µL, respectively. RT-LAMP showed similar performance to RT-PCR for samples with cycle threshold value below 36. CONCLUSIONS: These results indicate that RT-LAMP is a highly reliable and at least equivalent to RT-PCR in utility, and potentially applicable in settings that are more diverse as a point-of-care tool.

Factors significantly associated with COVID-19 severity in symptomatic patients: A retrospective single-center study.

INTRODUCTION: The severity of coronavirus disease (COVID-19) in Japanese patients is unreported. We retrospectively examined significant factors associated with disease severity in symptomatic COVID-19 patients (COVID-Pts) admitted to our institution between February 20 and April 30, 2020. METHODS: All patients were diagnosed based on the genetic detection of severe acute respiratory syndrome coronavirus 2. Information on the initial symptoms, laboratory data, and computed tomography (CT) images at hospitalization were collected from the patients' records. COVID-Pts were categorized as those with critical or severe illness (Pts-CSI) or those with moderate or mild illness (Pt-MMI). All statistical analyses were performed using R software. RESULTS: Data from 61 patients (16 Pt-CSI, 45 Pt-MMI), including 58 Japanese and three East Asians, were analyzed. Pt-CSI were significantly older and had hypertension or diabetes than Pt-MMI (P < 0.001, 0.014 and < 0.001, respectively). Serum albumin levels were significantly lower in Pt-CSI than in Pt-MMI (P < 0.001), whereas the neutrophil-to-lymphocyte ratio and C-reactive protein level were significantly higher in Pt-CSI than in Pt-MMI (P < 0.001 and P < 0.001, respectively). In the CT images of 60 patients, bilateral lung lesions were more frequently observed in Pt-CSI than in Pt-MMI (P = 0.013). Among the 16 Pt-CSI, 15 received antiviral therapy, 12 received tocilizumab, five underwent methylprednisolone treatment, six received mechanical ventilation, and one died. CONCLUSIONS: The illness severity of Japanese COVID-Pts was associated with older age, hypertension and/or diabetes, low serum albumin, high neutrophil-to-lymphocyte ratio, and C-reactive protein.

Efficacy of recombinant thrombomodulin for poor prognostic cases of acute exacerbation in idiopathic interstitial pneumonia: secondary analysis of the SETUP trial.

BACKGROUND: Acute exacerbation (AE) in idiopathic pulmonary fibrosis and other idiopathic interstitial pneumonias (IIPs) are poor prognostic events although they are usually treated with conventional therapy with corticosteroids and immunosuppressants. Previously, we demonstrated the safety and efficacy of recombinant human soluble thrombomodulin (rhTM) for AE-IIP in the SETUP trial. Here, we aimed to clarify the efficacy of rhTM for poor-prognosis cases of AE-IIP. METHODS: In this study, we included 85 patients, in whom fibrin degradation product (FDP)/d-dimer was evaluated at AE, from the 100 patients in the SETUP trial. The AE-IIP patients in the rhTM arm (n=39) were diagnosed using the Japanese criteria from 2014 to 2016 and treated with intravenous rhTM for 6 days in addition to the conventional therapy. The AE-IIP patients in the control arm (n=46) were treated with the conventional therapy without rhTM between 2011 and 2013. The subjects were classified into higher and lower FDP/d-dimer groups based on the Japanese Association for Acute Medicine Disseminated Intravascular Coagulation scoring system. A multivariate Cox proportional hazard regression analysis with stepwise selection was performed to reveal the prognostic factors of AE-IIP. RESULTS: We developed a prognostic scoring system using two significant prognostic factors, higher FDP/d-dimer at AE and prednisolone therapy before AE, with 3 and 2 points assigned for each parameter, respectively. The prognostic scores ranged from 0 to 5. Survival of AE-IIP patients with a prognostic score=0 was significantly better than that of patients with score ≥2. Survival was improved with the rhTM therapy (p<0.05) in the poor prognostic cases (score ≥2), but not in the good prognostic cases (score=0). CONCLUSIONS: Treatment with rhTM might improve survival in AE-IIP cases with poor prognoses.Trial registration numberUMIN000014969, date: 28 August 2014.

Invasive Tracheobronchial Aspergillosis with Bronchial Ulcers Complicated by Nontuberculous Mycobacterial Disease.

Invasive tracheobronchial aspergillosis (ITBA) complicated by nontuberculous mycobacteria (NTM) is rare. An 88-year-old man was admitted for hemoptysis. Bronchoscopy revealed bronchial ulcers, and a tissue biopsy showed Aspergillus fumigatus. He was diagnosed with ITBA, which improved with voriconazole. During treatment, infiltrative shadows appeared in his lungs, and bronchoscopy was performed once again. A non-necrotic epithelioid granuloma and Mycobacterium intracellulare were detected in the biopsy specimen. He was diagnosed with NTM disease. It is important to note that tracheobronchial ulcers may cause hemoptysis and to identify the etiology and treat it appropriately when multiple bacteria are found.

Recombinant thrombomodulin for acute exacerbation in idiopathic interstitial pneumonias.

BACKGROUND AND OBJECTIVE: Acute exacerbation (AE) in idiopathic pulmonary fibrosis (IPF) or other idiopathic interstitial pneumonias (IIP) is a poor prognostic event despite conventional therapy with corticosteroids and/or immunosuppressants. We aimed to evaluate the efficacy and safety of recombinant human soluble thrombomodulin (rhTM) for AE-IIP. METHODS: For this prospective single-arm open-label multicentre cohort study, we retrospectively registered 61 cases of AE-IIP treated with conventional therapy between 2011 and 2013 (control arm), and prospectively enrolled 39 cases of AE-IIP treated with conventional therapy and rhTM (380 U/kg/day for 6 days) between 2014 and 2016 (rhTM arm). To reduce potential confounding in treatment comparisons, an adjusted mortality analysis for 90-day survival was conducted with weighted Cox proportional hazards regression models using inverse probability of treatment weighting. Weights were derived from propensity scores estimated using a multivariable logistic regression analysis including potential confounders. RESULTS: The 90-day survival rates of AE-IIP patients treated with/without rhTM were 66.7% (26/39) and 47.5% (29/61), respectively. After adjusting for imbalances, rhTM therapy was significantly associated with reduced mortality (adjusted hazard ratio (HR): 0.453; 95% CI: 0.237-0.864; P = 0.0163). The frequencies of adverse events with/without rhTM were 17.9% (7/39) and 19.7% (12/61), which were similar in both arms (P = 1.0). Two bleeding-related adverse events occurred in the rhTM arm. CONCLUSION: Safety and efficacy were observed for rhTM treatment of AE-IIP. A future randomized controlled trial is required to draw final conclusions.

Spontaneous Regression of Allergic Bronchopulmonary Mycosis Due to Curvularia lunata.

Allergic bronchopulmonary mycosis (ABPM) is a pulmonary hypersensitivity disease mainly caused by Aspergillus fumigatus. The mainstay treatment for ABPM is systemic corticosteroid therapy. A 25-year-old man presented with pulmonary infiltrates. His peripheral eosinophil, total serum IgE, and serum Aspergillus-specific IgE levels were elevated. The patient tested positive in a skin test for Aspergillus. However, sputum cultures revealed a Curvularia lunata infection. We therefore diagnosed ABPM possibly caused by C. lunata, which is rare in Japan. The clinical state of the patient improved under observation. Identification of the causative fungus is an important aspect of the ABPM diagnosis.

Endoscopic Bronchial Occlusion with Silicon Spigots for the Treatment of an Alveolar-pleural Fistula during Anti-tuberculosis Therapy for Tuberculous Empyema.

A prolonged air leak caused by pulmonary tuberculosis is difficult to treat, and little is known about optimal treatment strategies. We herein report the case of a 60-year-old man who demonstrated tuberculous empyema with a fistula. An air leak from a tuberculous cavity in his left upper lobe persisted for approximately 4 months; surgical repair could not be performed due to a poor physical status and undernourishment. However, the air leak was successfully treated with endobronchial occlusion using two silicone spigots in left B3b and B4, without any adverse effects or aggravation of the infection.

[A case of severe COPD associated with tracheo-bronchial stenosis, treated with non-invasive positive pressure ventilation].

A 76-year-old man was admitted with acute exacerbation of COPD. He was administered bronchodilators, antibiotics and oral corticosteroids. Although his cough, sputum, fever and the laboratory data improved. wheezing and dyspnea remained. The chest CT revealed severe stenosis of the trachea and both main bronchi, which was thought to be the cause of the symptoms, and similar to the condition of "excessive dynamic airway collapse (EDAC)". We treated him with NPPV and his symptoms improved and he returned home. "EDAC"-like tracheobronchial stenosis with COPD treated with NPPV is rare.

Gefitinib-sensitive EGFR lacking residues 746-750 exhibits hypophosphorylation at tyrosine residue 1045, hypoubiquitination, and impaired endocytosis.

Gefitinib-sensitive nonsmall cell lung cancers (NSCLC) are characterized by somatic mutations in the kinase domain of epidermal growth factor receptor (EGFR). The mutant EGFR forms are reported to mediate characteristic signal transduction pathways that are different from those mediated by the wild-type EGFR and are involved in transformation in vivo. We have examined signal transduction pathways initiated from a frequently identified gefitinib-sensitizing mutant EGFR lacking residues 746-750 by employing a mouse fibroblast cell line that is free of endogenous EGFR and transiently transfected COS-7 cells. Upon EGF stimulation, the deletion-mutant EGFR mediated prolonged downstream signals. The analysis of the phosphotyrosine patterns of the receptor revealed that the deletion-mutant EGFR lacked phosphorylation at tyrosine residue 1045, which is the major binding site of Cbl. The EGF-induced endocytosis of the deletion-mutant EGFR was impaired. The ubiquitination and downregulation of the deletion-mutant EGFR were also reduced. On the other hand, another mutant, EGFR, possessing a L858R substitution, exhibited phosphorylation at 1045 and its downstream signalings were not prolonged. These data suggest that the signal transduction pathways initiated from these mutant forms are different, and that impaired endocytosis might be responsible for the prolonged signals mediated by the deletion-mutant EGFR.

Short-term gefitinib treatment brought about a long-term regression of bronchioloalveolar carcinoma without EGFR gene alterations: a case report.

The tyrosine kinase inhibitor (TKI) of the epidermal growth factor receptor (EGFR) gefitinib has beneficial effect in some patients with refractory advanced non-small cell lung cancer (NSCLC). However, the majority of responders eventually develop acquired resistance during the course of prolonged continuous treatment. Here we present a case of 76-year-old Japanese female, who had never smoked, with poor performance status from bronchioloalveolar carcinoma (BAC), in whom a brief initial 5-week administration of gefitinib resulted in dramatic antitumor effects that lasted approximately 8.5 months after cessation of the treatment. Furthermore, the relapsed tumor later regressed again by re-treatment with the TKI. She survived 26 months since she first took gefitinib. Unexpectedly, neither sensitizing mutations for EGFR-TKIs nor increased copy numbers were detected in EGFR gene of her BAC cells. This case suggests that, in some patients with NSCLC, even short-term administration of gefitinib may bring about clinical benefits and disease response comparable to the standard long-term daily dosing schedule. Short-term use of gefitinib will also be able to minimize the expensive medical cost of the TKI. The potential role of short-term or pulse-dose therapy with EGFR-TKIs should be clarified in further prospective studies. Moreover, it is urgent to develop better strategies by which we could distinguish responders to the TKIs from nonresponders among patients who do not have any EGFR gene alterations.

A case of alpha-thalassemia-2 associated with pulmonary infarction.

Pulmonary infarction is an entity of medical significance that develops concurrently in beta-thalassemia but not in alpha-thalassemia. The reason for this difference is yet to be elucidated. We have evaluated a 21-year-old male alpha-thalassemia-2 patient who had profound microcytic anemia and pulmonary infarction. Analysis of the alpha-globin gene revealed -alpha3.7/alpha alpha genotype. His mother also had the same heterozygous gene deletion, though she had neither anemia nor pulmonary infarction. Since the patient had no other predisposition to pulmonary infarction, it is suggested that there is a close etiologic relationship between morphologic abnormality of the erythrocytes caused by alpha-thalassemia-2 and development of pulmonary infarction.

Plasminogen-mediated activation and release of hepatocyte growth factor from extracellular matrix.

Interventions that enhance plasminogen activation within the lung consistently limit the fibrosis that follows alveolar injury. However, this protective effect cannot be attributed solely to accelerated clearance of fibrin that forms as a provisional matrix after lung injury. To explore other mechanisms, we considered interactions between the plasminogen activation system and hepatocyte growth factor (HGF). HGF is known to have antifibrotic activity, but to do so, it must be both released from its sites of sequestration within extracellular matrix (ECM) and activated by proteolytic cleavage. A recent study using bleomycin-exposed mice showed that manipulations of the plasminogen activation system influenced the amount of free HGF within bronchoalveolar lavage fluid without affecting total lung HGF mRNA or protein. To elucidate the mechanisms, we studied the role of plasminogen activation in fibroblast-mediated HGF release and activation. We found that NIH3T3 and mouse lung fibroblasts release ECM-bound HGF in a plasminogen-dependent fashion. The plasminogen effect was lost when lung fibroblasts from urokinase-type plasminogen activator (uPA)-deficient mice were used, and was increased by fibroblasts from plasminogen activator inhibitor (PAI)-1-deficient mice. Plasminogen addition to NIH3T3 or mouse lung fibroblasts increased conversion of pro-HGF to its active form. The plasminogen effect on activation was lost when uPA-deficient fibroblasts were used and accentuated by PAI-1-deficient fibroblasts. In conjunction with the previous in vivo study, these results suggest that plasminogen activation can protect the lung against fibrosis by increasing the availability of active HGF.

Usefulness of ultrathin bronchoscopy in diagnosis of lung cancer.

Although ultrathin bronchoscopes are suggested to have comparable abilities to conventional bronchoscopes in diagnosing peripheral lung lesions, how to introduce ultrathin bronchoscopes into bronchoscopic examination is still to be determined. In our first study, 35 patients with peripheral lung lesions underwent ultrathin followed by conventional bronchoscopy to compare their diagnostic abilities. The diagnostic rate was 54.3% in conventional bronchoscopy alone, 60.0% in ultrathin bronchoscopy alone, and 62.8% in the combination of the two. In the next study, we introduced a rapid cytology test of the material obtained in conventional bronchoscopy. When malignant cells were not detected in the material by the rapid cytology, ultrathin bronchoscopy was immediately conducted. Thirty-two patients with negative rapid cytology were enrolled in this study. Ultrathin bronchoscopy resulted in diagnostic materials in 59.3% of these cases. Ultrathin bronchoscopes showed better access to the lesions than a brush or a curette introduced through conventional bronchoscopes. We conclude that ultrathin bronchoscopes have a comparable ability to conventional ones in diagnosing peripheral lung cancer even when used alone, and become a good complement to conventional ones by introducing the rapid cytology test.

Increased level of soluble E-selectin in the serum from patients with idiopathic pulmonary fibrosis.

To elucidate the biological significance of selectin for idiopathic pulmonary fibrosis, we titrated the serum soluble E-selectin. From 31 cases of idiopathic pulmonary fibrosis patients without signs or symptoms of infection, the serum was obtained and the concentration was titrated by enzyme-linked immunosorbent assay. The serum soluble E-selectin titer was significantly higher than that of healthy controls. However, significant elevation was not observed in the sera from the patients with other pulmonary diseases, such as pulmonary emphysema, sarcoidosis, or bronchiectasis. In the patients with idiopathic pulmonary fibrosis, the number of white blood cells, C-reactive protein or lactate dehydrogenase activity did not show a significant relationship with the soluble E-selectin titer. About 16 out of the 31 idiopathic fibrosis patients, the serum surfactant apoprotein-A titer, which is a parameter of the disease activity of idiopathic pulmonary fibrosis, was also tested. The surfactant apoprotein-A titer was loosely correlated with the soluble E-selectin titer. These observations suggest that E-selectin may be relevant to the pathogenesis of idiopathic pulmonary fibrosis, and it may be a novel clinical parameter for idiopathic pulmonary fibrosis.

Hepatoma-derived growth factor is involved in lung remodeling by stimulating epithelial growth.

Lung epithelial cells have an integral role in the maintenance of lung homeostasis; however, the regulatory mechanism thereof has not been fully clarified. Recently, hepatoma-derived growth factor (HDGF) was reported to be involved in organ development and remodeling through its mitogenic effect. We investigated the biological role of HDGF in lung remodeling. HDGF was more highly expressed in the lungs of idiopathic pulmonary fibrosis, chiefly in the epithelial cells, than in control nonfibrotic lungs. We also confirmed the expression of HDGF protein and mRNA in the lungs of bleomycin-instilled mice, mainly in the bronchial and alveolar epithelial cells, by immunohistochemical analysis and in situ hybridization. We found that recombinant HDGF promoted DNA synthesis in rat alveolar epithelial cells and A549 cells in vitro. Endogenous HDGF overexpressed by gene transfer was translocated into the nucleus and promoted the proliferation of A549 cells. In vivo intratracheal instillation of recombinant HDGF induced the proliferation of bronchial and alveolar epithelial cells without causing marked interstitial inflammation. These findings suggest that HDGF may be involved in lung remodeling after injury by promoting the proliferation of lung epithelial cells, probably in an autocrine manner.