Effects of doxycycline on production of growth factors and matrix metalloproteinases in pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrosis and a poor prognosis. Alveolar epithelial cells (AECs) are considered to play important roles by releasing growth factors and matrix metalloproteinases (MMPs) and by being involved in epithelial mesenchymal transition in IPF. Doxycycline hydrochloride (DOXY), an inhibitor of MMPs, attenuates pulmonary fibrosis in models and in patients with IPF; however, the mechanism of this action remains obscure. OBJECTIVES: The present study investigated the effect of DOXY on growth factors and MMP production in AECs. METHODS: Bleomycin (BL)-induced murine pulmonary fibrosis was treated with DOXY and examined by pathological and immunohistochemical staining. The human alveolar epithelial cell line A549 was stimulated with transforming growth factor (TGF)-ß1 and incubated with DOXY, and then the expression of growth factors, MMPs, and collagen type I was evaluated at the mRNA and protein levels. We also evaluated the effects of DOXY on the TGF-ß1-induced Smad signaling pathway. RESULTS: DOXY reduced fibrosis scores and the production of collagen type I, connective tissue growth factor (CTGF), and TGF-ß1 in BL models. DOXY inhibited the mRNA expression of MMP-2, MPP-9, CTGF, and collagen type I as well as the production of MMP-2 and platelet-derived growth factor-AA protein induced in A549 cells by TGF-ß1 but not by Smad2 and Smad3 phosphorylation. We did not find a similar effect of DOXY in normal lung fibroblasts. CONCLUSIONS: Our results suggest that DOXY could be useful for attenuating pulmonary fibrosis through the inhibition of growth factors and MMP production in AECs.

[A case of Paragonimus westermani complicated empyema by Streptococcus pneumoniae].

A 75-year-old man, who had eaten wild boar and deer repeatedly until November 2006, visited our hospital because of a right pleural effusion on chest X-ray films after he bruised a hip in January 2007. A right thoracocentesis revealed exudative pleural effusion with many neutrophils. Ten days after his first visit, a pleural biopsy specimen suggested the existence of parasite eggs. Twenty-six days after his first visit, he was admitted to our hospital because of leukocytosis, increased systemic inflammatory markers and a right pleural effusion. We found a great number of neutrophils, eggs of the Paragonimus species and gram-positive cocci in the pleural effusion. Streptococcus pneumoniae was also identified in his pleural effusion. In addition, a diagnosis of Paragonimiasis westermani was made serological study. After the continuous drainage of the pleural effusion, the patient was treated with praziquantel and antibiotics, and he gradually improved.

Macrolide antibiotics induce apoptosis of human peripheral lymphocytes in vitro.

We previously reported that long-term administration of macrolides (MCL) reduced the number of lymphocytes in bronchoalveolar lavage fluid (BALF) of patients with chronic lower respiratory tract disease. To investigate the anti-inflammatory activity of macrolides, we evaluated their effect on apoptosis of lymphocytes isolated from human peripheral blood. Lymphocytes treated with clarithromycin, azithromycin and josamycin at a final concentration of 200 microg/ml showed positive staining for Annexin V, Fas and Fas ligand using flow cytometry with time at 12-72 h, while other antibiotics did not. Our results suggest that macrolides induce apoptosis of lymphocytes through Fas-Fas ligand pathway and could potentially reduce the number of lymphocytes in the lungs of patients with chronic lower respiratory tract disease.

Effect of erythromycin on chronic respiratory infection caused by Pseudomonas aeruginosa with biofilm formation in an experimental murine model.

Diffuse panbronchiolitis (DPB) is a chronic lower respiratory tract infection commonly associated with persistent late-stage Pseudomonas aeruginosa infection. However, low-dose long-term therapy with certain macrolides is effective in most patients with DPB. The present study was designed to examine the effects of long-term erythromycin (ERY) therapy by using our established murine model of chronic respiratory P. aeruginosa infection. ERY or saline was administered from day 80 after intubation with a P. aeruginosa-precoated tube for the subsequent 10, 20, 40, and 80 days. Bacteriologic and histologic analyses of the murine lungs and electron microscopy of the intubated tube were performed. In the murine model, treatment with ERY for 80 days significantly reduced the number of viable P. aeruginosa organisms in the lungs (P < 0.05). The biofilm formed in situ by P. aeruginosa on the inner wall of the inoculation tube placed into the murine bronchus became significantly thinner after 80 days of ERY treatment. We conclude that the clinical efficacy of macrolides in DPB may be due at least in part to the reduction in P. aeruginosa biofilm formation.

Giant cell interstitial pneumonia in a 15-year-old boy.

Giant cell interstitial pneumonia (GIP) is a very uncommon respiratory disease. We report a juvenile patient with GIP aged 15 years. Although he has a negative past history of direct exposure to hard metals, we could not exclude possible exposure in very small amounts through his parents. Microscopic examination of lung biopsy specimen obtained by video-assisted thoracoscopy revealed marked cellular interstitial infiltrates and prominent intraalveolar macrophages as well as giant cells showing cellular cannibalism. Analysis of the biopsied lung tissue for cobalt and tungsten was negative. Clinical symptoms, laboratory, and radiological findings improved markedly after treatment with corticosteroids. To our knowledge, only eleven cases of GIP have been reported in Japan. Although possible exposure to hard metals was identified in 9 of the 11 reported cases, there is no clear dose-dependent relationship with onset and prognosis. The average age at onset was 46.2+/-15.0 years. Our patient is the youngest case of GIP reported in the world.

[Comparison of bronchoalveolar lavage fluids from nonspecific interstitial pneumonia and from ordinary interstitial pneumonia].

We studied cell findings in the bronchoalveolar lavage fluid (BALF) of 13 patients with nonspecific interstitial pneumonia (NSIP) and 20 with ordinary interstitial pneumonia (UIP). NSIP and UIP were difficult to distinguish by high-resolution CT. Surgical lung biopsies were performed in all patients. We divided the patients with NSIP and UIP into 4 groups, a group of idiopathic NSIP (idiopathic NSIP), a group of NSIP patients associated with collagen vascular disease (CVD NSIP), a group of idiopathic UIP patients (idiopathic UIP) and a group of UIP patients associated with collagen vascular disease (CVD UIP). We then examined the differences in BALF cell findings between these groups. The percentage of lymphocytes in BALF was higher in idiopathic NSIP and CVD NSIP than in the healthy control. The percentage of alveolar macrophages was lower and the percentage of lymphocytes was higher in CVD NSIP than in idiopathic UIP. The CD4/CD8 ratio in BALF of idiopathic NSIP was lower than with idiopathic UIP. It is important that NSIP be distinguished from UIP clinically, and our results suggest that BALF cell findings may be useful for making this distinction.

[Desquamative interstitial pneumonia--case report and review of literature].

A 50-year-old man was admitted to our hospital because diffuse reticulonodular shadows in the bilateral lung fields had deteriorated on chest radiographs during a regular checkup. The bronchoalveolar lavage (BAL) fluid revealed an increase in the total number of cells, including slightly elevated levels of eosinophils and neutrophils. The thoracoscopic lung biopsy specimens showed findings compatible with desquamative interstitial pneumonia (DIP). Corticosteroid therapy was done, and improvement of chest CT findings and pulmonary function were seen. We reviewed the clinical features in seventeen patients with biopsy-proven DIP reported in Japan. All patients have good prognoses and a high frequency of steroid responsiveness. Moreover, many patients were positive for antinuclear antibodies in serological tests, and there was a tendency toward increasing eosinophils in BAL fluids.

[A case of endobronchial sarcoidosis presenting as a polypoid lesion].

A 51-year-old woman was admitted to our hospital because of deterioration of abnormal chest shadows. Though the shadows had been pointed out at another hospital about two years before, no evaluation had been made at that time. A chest CT scan showed multiple small nodular shadows and thickening of the bronchovascular bundles bilaterally, and marked swollen lymph nodes in the axilla, mediastinum, and bilateral the hili of both lungs. Bronchoscopic evaluation revealed bronchial mucosal hypervascularity and a polypoid lesion at the orifice of the right B8b. The transbronchial biopsy specimen of the polypoid lesion showed non-caseating epithelioid cell granulomas in the bronchial mucosa. The bronchoalveolar lavage revealed a increase in the total number of cells including high levels of lymphocytes. Therefore, a diagnosis of sarcoidosis was made. This is a very rare case of endobronchial sarcoidosis. However, biopsy specimens of normal mucosa in sarcoidosis often show a microscopic sarcoid process, so a diagnosis of endobronchial sarcoidosis in this case should be given prudently.