The effects of oxidative stress induced by prolonged low-dose diesel exhaust particle exposure on the generation of allergic airway inflammation differ between BALB/c and C57BL/6 mice

We have recently reported that airway inflammatory responses to the oxidative stress induced by prolonged low-dose diesel exhaust particle (DEP) exposure differ markedly between BALB/c and C57BL/6 mice. In the present study, the effects of genetic differences in the response to prolonged low-dose DEP exposure on the generation of ovalbumin-induced allergic airway inflammation were further explored using the same mouse strains. In BALB/c mice, eosinophils and mucous goblet cells in histopathological pulmonary specimens increased significantly after DEP exposure, and were more marked than in C57BL/6 mice. Interleukin (IL)-5 and IL-13 levels in bronchoalveolar lavage (BAL) fluid were increased significantly by DEP exposure only in BALB/c mice. The DEP-induced increases in peribronchial eosinophils and mucous goblet cells in the lung tissues, and of IL-5 and IL-13 in the BAL fluid, were significantly attenuated by the antioxidant N-acetylcysteine. Thus, the effects of prolonged low-dose DEP exposure on the generation of allergic airway inflammation differed markedly between the mouse strains. These differences may be caused by different antioxidant responses to the oxidative stress induced by DEP exposure. Our results contribute more information to the search for genetic susceptibility factors in the response to DEP, and may thus assist in the discovery of new biomarkers for DEP-related disease.

Pirfenidone: antifibrotic agent for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a devastating disease with rare incidence but high mortality, and the pathogenesis of which is still poorly understood. Available treatment options have been empirically applied but evidence-based benefits have not yet been confirmed. Pirfenidone is an antifibrotic agent that is potentially effective for IPF treatment. Preclinical studies have been reported using experimental animal models, which revealed inhibitory effects pn profibrotic and proinflammatory cytokines. Several clinical studies provided promising and reproducible effects for inhibition of IPF disease progression in different nations. The efficacy is demonstrated in patients with mild-to-moderate impairment of pulmonary functions, but not confirmed for patients with severe impairment. Major adverse events are photosensitivity and anorexia, but the treatment was generally safe and well tolerated. In this article, the usefulness and limitations of pirfenidone in IPF treatment are discussed to determine its potential for the management of IPF progression.

Heat shock protein 70 protects against bleomycin-induced pulmonary fibrosis in mice

Idiopathic pulmonary fibrosis (IPF) involves infiltration of leucocytes, pulmonary injury, fibrosis and resulting pulmonary dysfunction. Myofibroblasts and transforming growth factor (TGF)-beta1 have been suggested to play a major role in the pathology and the myofibroblasts are derived from both lung epithelial cells through epithelial-mesenchymal transition (EMT) and activation of lung fibroblasts. Heat shock protein 70 (HSP70) confers protection against various stressors and has the anti-inflammatory activity. In this study, we examined the effect of expression of HSP70 on bleomycin-induced pulmonary fibrosis in mice, a tentative animal model of IPF. Bleomycin-induced pulmonary injury and inflammatory response were ameliorated in transgenic mice overexpressing HSP70 compared to wild-type mice, even though bleomycin-induced pulmonary fibrosis and dysfunction were also suppressed in the transgenic mice. The production of TGF-beta1 and expression of pro-inflammatory cytokines was lower in cells from the transgenic mice than wild-type mice after the administration of bleomycin. In vitro, the suppression of HSP70 expression stimulated TGF-beta1-induced EMT-like phenotypes of epithelial cells but did not affect the TGF-beta1-dependent activation of fibroblasts. Orally administered geranylgeranylacetone (GGA), a clinically used drug with HSP-inducing activity, conferred protection against bleomycin-induced pulmonary injury, as well as against the inflammatory response, fibrosis and dysfunction. These results suggest that HSP70 plays a protective role against bleomycin-induced pulmonary injury, inflammation, fibrosis and dysfunction through cytoprotective effects and by inhibiting the production of TGF-beta1, TGF-beta1-dependent EMT of epithelial cells and expression of pro-inflammatory cytokines. Results also suggest that HSP70-inducing drugs, such as GGA, could be beneficial in the prophylaxis of IPF.

Neutrophil adsorption by polymyxin B-immobilized fiber column for acute exacerbation in patients with interstitial pneumonia: a pilot study

BACKGROUND/AIMS

Polymyxin B-immobilized fiber (PMX) treatment has beneficial effects in patients with acute lung injury/acute respiratory distress syndrome or acute exacerbation of idiopathic pulmonary fibrosis. This study was aimed to clarify the mechanism of PMX treatment for acute exacerbation of interstitial pneumonia (IP).

MATERIALS AND METHODS

Sixteen consecutive IP patients with acute exacerbation were included. The patients were treated with PMX once daily for 2 successive days at a flow rate of 80-100 ml/min for 6 h. Cells adsorbed by PMX were analyzed morphologically by electron microscopy. Surface markers of these cells were determined by flow cytometry. Serum matrix metalloproteinase (MMP)-9 was measured before and after PMX treatment.

RESULTS

Cells adsorbed by PMX were neutrophils and highly expressed HLA-DR, CD14, CD62L and CD114. Serum MMP-9 levels were significantly decreased after PMX treatment.

CONCLUSION

This pilot study demonstrated neutrophil adsorption by PMX and its possible clinical application for acute exacerbation of IP.

Therapeutic effect of lecithinized superoxide dismutase on bleomycin-induced pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is thought to involve inflammatory infiltration of leukocytes, lung injury induced by reactive oxygen species (ROS), in particular superoxide anion, and fibrosis (collagen deposition). No treatment has been shown to improve definitively the prognosis for IPF patients. Superoxide dismutase (SOD) catalyzes the dismutation of superoxide anion to hydrogen peroxide, which is subsequently detoxified by catalase. Lecithinized SOD (PC-SOD) has overcome clinical limitations of SOD, including low tissue affinity and low stability in plasma. In this study, we examined the effect of PC-SOD on bleomycin-induced pulmonary fibrosis. Severity of the bleomycin-induced fibrosis in mice was assessed by various methods, including determination of hydroxyproline levels in lung tissue. Intravenous administration of PC-SOD suppressed the bleomycin-induced increase in the number of leukocytes in bronchoalveolar lavage fluid. Bleomycin-induced collagen deposition and increased hydroxyproline levels in the lung were also suppressed in animals treated with PC-SOD, suggesting that PC-SOD suppresses bleomycin-induced pulmonary fibrosis. The dose-response profile of PC-SOD was bell-shaped, but concurrent administration of catalase restored the ameliorative effect at high doses of PC-SOD. Intratracheal administration or inhalation of PC-SOD also attenuated the bleomycin-induced inflammatory response and fibrosis. The bell-shaped dose-response profile of PC-SOD was not observed for these routes of administration. We consider that, compared with intravenous administration, inhalation of PC-SOD may be a more therapeutically beneficial route of administration due to the higher safety and quality of life of the patient treated with this drug.

Pirfenidone in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease without proven effective therapy. A multicentre, double-blind, placebo-controlled, randomised phase III clinical trial was conducted in Japanese patients with well-defined IPF to determine the efficacy and safety of pirfenidone, a novel antifibrotic oral agent, over 52 weeks. Of 275 patients randomised (high-dose, 1,800 mg x day(-1); low-dose, 1,200 mg x day(-1); or placebo groups in the ratio 2:1:2), 267 patients were evaluated for the efficacy of pirfenidone. Prior to unblinding, the primary end-point was revised; the change in vital capacity (VC) was assessed at week 52. Secondary end-points included the progression-free survival (PFS) time. Significant differences were observed in VC decline (primary end-point) between the placebo group (-0.16 L) and the high-dose group (-0.09 L) (p = 0.0416); differences between the two groups (p = 0.0280) were also observed in the PFS (the secondary end-point). Although photosensitivity, a well-established side-effect of pirfenidone, was the major adverse event in this study, it was mild in severity in most of the patients. Pirfenidone was relatively well tolerated in patients with IPF. Treatment with pirfenidone may decrease the rate of decline in VC and may increase the PFS time over 52 weeks. Additional studies are needed to confirm these findings.

Differences in the clinical characteristics of Pneumocystis jirovecii pneumonia in immunocompromized patients with and without HIV infection

BACKGROUND AND OBJECTIVE

The incidence of Pneumocystis jirovecii pneumonia (PCP) in patients with predisposing immunodeficiencies other than AIDS is growing. Knowing the different characteristics and outcomes of PCP according to HIV status would help physicians manage and treat patients with PCP.

METHODS

The medical charts of all patients with a proven first episode of PCP, diagnosed between 1997 and 2007 were retrospectively reviewed, and clinical and laboratory data abstracted.

RESULTS

Of the 35 patients with PCP, 18 were HIV-positive and 17 were HIV-negative with other immunosuppressive conditions. HIV-negative patients were significantly older than HIV-positive patients. The WCC (10 952 +/- 5669 vs 9750 +/- 3133/microL; P = 0.015), neutrophil counts (9631 +/- 5421 vs 5680 +/- 2628/microL; P = 0.01) and CD4+ lymphocyte counts (329 +/- 502 vs 47 +/- 50/microL; P < 0.001) were significantly higher in HIV-negative patients. Six of the 17 HIV-negative patients had a CD4+ lymphocyte count >300/microL. Serum IgG levels were lower in HIV-negative patients (943 +/- 379 vs 1635 +/- 657 mg/dL; P = 0.017). Mortality was higher in HIV-negative (52.9%) than in HIV-positive patients (0%). On univariate analysis, risk factors for mortality from PCP were the presence of underlying pulmonary disease (odds ratio 4.000, 95% CI: 1.501-10.658) and HIV-negative status (odds ratio 2.125, 95% CI: 1.283-3.518).

CONCLUSIONS

The characteristics and outcomes of PCP differ significantly depending on HIV status. The existence of underlying pulmonary diseases may be associated with the prognosis of HIV-negative patients with PCP.

AIRWAY INFLAMMATORY RESPONSES TO OXIDATIVE STRESS INDUCED BY LOW-DOSE DIESEL EXHAUST PARTICLE EXPOSURE DIFFER BETWEEN MOUSE STRAINS

Low-dose diesel exhaust particle (DEP) exposure induces airway inflammation and exaggerates asthmatic responses in mice, but it is unclear whether strains differ in their susceptibility to adverse effects from low-dose DEP exposure. The authors used BALB/c and C57BL/6 mouse strains to search for genetically based differences in response to low-dose DEP (100 microg/m(3)) exposure in terms of airway inflammatory response. The macrophage count in bronchoalveolar lavage (BAL) fluid soon after DE exposure began was significantly greater in C57BL/6 mice (P < .05) than that in BALB/c mice. The count did not increase significantly in BALB/c mice until later. Heme oxygenase-1 (HO-1) mRNA expression and protein production in lung tissues soon after exposure began were more marked in BALB/c mice than in C57BL/6 mice, but the reverse was true later on. The increases in interleukin (IL)-1beta and interferon (IFN)-gamma levels in BAL fluid after DE exposure were significant only in BALB/c mice; there were significantly increases in monocyte chemoattractant protein (MCP)-1, IL-12, IL-10, IL-4, and IL-13 in both strains, but these were more marked in C57BL/6 mice. These interstrain differences in airway inflammatory response after DE exposure were significantly attenuated by antioxidant N-acetylcysteine (NAC) treatment. Changes in airway hyperresponsiveness were independent of the airway inflammation induced by low-dose DEP. Thus, in BALB/c mice, innate immunity may play a central role in DE exposure response, whereas in C57BL/6 mice Th2-dominant responses play a central role. Low-dose DEP exposure induces airway inflammatory responses that differ among strains, and these differences may be caused by differences in sensitivity to oxidative stress.

THE EFFECTS OF INHALATION OF DIESEL EXHAUST ON MURINE MYCOBACTERIAL INFECTION

The authors investigated the effects of inhalation of diesel exhaust (DE) on murine mycobacterial infection in vivo. Eight-week-old female BALB/c mice were exposed to DE (3 mg/m3 of diesel exhaust particles [DEPs]) for 1 month, 2 months, or 6 months (for 7 hours a day, 5 days a week). Control mice were housed in a clean room for the same periods. On the day following the last DE exposure, control mice and DE-exposed mice were aerially infected with Mycobacterium tuberculosis (1 x 10(6) colony-forming units (CFU), Kurono strain). At 7 weeks after mycobacterial infection, the authors examined the lung tissues for histopathological changes and performed reverse transcriptase-polymerase chain reaction (RT-PCR) to measure the messenger RNA (mRNA) expression of several proinflammatory cytokines and inducible nitric oxide synthase (iNOS). Then, the homogenates of lungs and spleens were cultured on 1% (v/v) Ogawa's egg slant medium, and after a 4-week incubation period at 37 degrees C, colonies on the medium were counted. After 1 month of DE exposure, the mycobacterial infection had slightly ameliorated. After 2 months of DE exposure, the expression levels of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-12p40, interferon (IFN)-gamma, and iNOS mRNAs were slightly increased. However, after 6 months of DE exposure, the expression levels of IL-1beta , IL-12p40, IFN-gamma, and iNOS mRNAs were decreased, and the infection as measured by increased lung burden (CFU) actually increased. These results indicate that long-term DE exposure may increase pulmonary mycobacterial burden.

[A case of suspected idiopathic pulmonary upper lobe fibrosis (Amitani disease) with acute exacerbation]

An 82-year old man was admitted to our hospital for evaluation of progressive general malaise. He had previously been in good health. His chest roentgenogram showed reticular shadows and we suspected interstitial lung disease. On admission, his roentgenographic images showed deterioration compared with previous images. Acute lung injury was diagnosed by transbronchial lung biopsy, and steroid administration was started. He initially responded to treatment, but bilateral spontaneous pneumothorax occurred. Despite treatment, he died of respiratory failure. Amitani disease (idiopathic pulmonary upper lobe fibrosis) was suspected based on postmortem pathology, but his lung parenchyma was poor due to the presence of changes producing diffuse alveolar damage. We report and discuss this case because there are apparently no previous similar cases.

Exacerbation of idiopathic interstitial pneumonias associated with lung cancer therapy

OBJECTIVE AND METHODS

Idiopathic interstitial pneumonias (IIPs) frequently occur in association with lung cancer. However, there is no consensus on the best treatment of acute exacerbation of IIP in lung cancer patients (LC with IIP), including those with iatrogenic acute lung injury resulting from cancer treatments. We aimed to identify an appropriate strategy for treatment of this condition. We analyzed clinical features of 120 LC with IIP, retrospectively.

RESULTS

The incidence of acute exacerbation related to anticancer treatment was 22.7%; when the incidence was examined separately for patients receiving chemotherapy or the best supportive care, the incidence was 20.0% and 31.3%, respectively. Additional investigations should be directed to finding suitable regimens for treatment of LC with IIP and the selection of appropriate patients with LC with IIP for chemotherapy. The incidence of acute exacerbation caused by combination regimens of carboplatin + paclitaxel or a platinum agent + etoposide was significantly lower than that of other regimens (0% vs. 18%, respectively; p=0.025, Fisher's Exact Test). Patients with high levels of C-reactive protein before chemotherapy had a significantly higher risk of developing acute exacerbation (odds ratio 5.60, p=0.028).

CONCLUSION

There was no evidence that anticancer treatment, including chemotherapy, should be avoided in LC with IIP. To establish an appropriate cancer treatment for LC with IIP, a prospective clinical study should be performed to evaluate various treatment modalities in a larger patient population.

Evaluation of fractional analysis of bronchoalveolar lavage combined with cellular morphological features

BACKGROUND

The value of bronchoalveolar lavage (BAL) still remains controversial, prompting a need for further improvement. The purpose of this study was to develop and evaluate a sequential analysis of cell content in fractional BAL (FBAL) from the airways and alveolar sacs with incorporation of the cellular morphologic features.

METHODS

Initially, 30 ml saline was infused into a subsegmental lobe of the lung and the recovered fluid was assigned as FBAL-I being mainly originated from whole airways. The second and third lavages (FBAL-II and FBAL-III) each were performed using 50 ml saline being from more distal portions of airways and alveolar sacs respectively in the same lobe. Total cell number/ml and percentages of macrophages, lymphocytes, neutrophils, and eosinophils in each fraction together with their morphological alterations and mast cells, basophils and Masson bodies were assessed.

RESULTS

In the 12 controls, percentage of neutrophils was high and lymphocytes and macrophages were low in FBAL-I while in FBAL-III, neutrophils decreased to nearly nil and lymphocytes and macrophages were increased. Analysis of FBAL from 76 patients with sarcoidosis and 14 with hypersensitivity pneumonitis (HP) revealed that a predominance of small, round and well-differentiated lymphocytes with relative absence of neutrophils, basophils and Masson bodies correlated best with sarcoidosis. In contrast, neutrophil predominance and presence of lymphocytes having deep nuclear indentations and abundant cytoplasm with a process resembling a "hand-mirror" correlated well with HP.

CONCLUSIONS

Evaluation of FBAL together with cellular morphological features especially characteristics of lymphocytes provides valuable information for establishing the diagnosis in interstitial lung diseases.

EM703, a new derivative of erythromycin, inhibits transforming growth factor-beta signaling in human lung fibroblasts

Long-term, low-dose macrolide therapy has been proven to improve survival in patients with diffuse panbronchiolitis and cystic fibrosis, although the mechanisms by which it does so remain unknown. To elucidate the molecular mechanisms of the anti-inflammatory effects of macrolides, the authors examined the effects of erythromycin (EM-A) and new derivative EM703 on transforming growth factor (TGF)-beta /Smad signaling fibroblasts. EM-A and EM703 each inhibited fibroblast proliferation and the collagen production in human lung fibroblasts induced by TGF-beta. EM-A and EM703 inhibited the augmentation of Smad3 mRNA induced by TGF-beta. Smad7 mRNA was inhibited by TGF-beta, but augmented by coincubation with EM-A or EM703. EM-A and EM703 each inhibited p-Smad2/3 proteins induced by TGF-beta. Smad7 protein inhibited by TGF-beta restored beyond basal level by EM-A and EM703. These findings suggest that EM-A and EM703 inhibit TGF-beta signaling in human lung fibroblasts via inhibition of p-Smad2/3 through recovery of Smad7 level.

Airway inflammatory responses to oxidative stress induced by prolonged low-dose diesel exhaust particle exposure from birth differ between mouse BALB/c and C57BL/6 strains

The authors used BALB/c and C57BL/6 mouse strains to search for genetically based differences in response to prolonged (6 months) low-dose (100 microg/m3) diesel exhaust particle (DEP) exposure from birth in terms of airway inflammatory responses. Histopathological assessment showed that inflammatory cells infiltrated the perivascular areas only in C57BL/6 mice. The count of DEP-laden alveolar macrophages in bronchoalveolar lavage (BAL) fluid was significantly greater in BALB/c mice (P < .05) than in C57BL/6 mice. The lymphocyte and eosinophil count in BAL fluid was significantly greater in C57BL/6 mice (P < .05) than in BALB/c mice. Immunoglobulin (Ig) IgG1 and IgG2 levels in serum, and the monocyte chemoattractant protein (MCP)-1 level in BAL fluid were significantly greater in BALB/c mice than in C57BL/6 mice. The interleukin (IL)-12 level in BAL fluid was significantly greater in C57BL/6 mice than in BALB/c mice, but the IL-13 level in BAL fluid was significantly less in BALB/c mice than in C57BL/6 mice. Glutathione S-transferase (GST) mRNA expression and protein production in lung tissues were significantly lower in C57BL/6 mice than in BALB/c mice, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) level in the lung tissues were significantly greater in C57BL/6 mice than in BALB/c mice. In conclusion, prolonged low-dose DEP exposure induces airway inflammatory responses that differ remarkably among mouse strains; these differences are caused by differences in the host defense response to the oxidative stress induced by DEP exposure and may be useful in the development of biomarkers.

Clinical factors on cavitary and nodular bronchiectatic types in pulmonary Mycobacterium avium complex disease

BACKGROUND AND OBJECTIVE

Pulmonary Mycobacterium avium complex (MAC) disease is the most common pulmonary non-tuberculous mycobacteriosis (NTM). The clinical and radiological findings were similar to those of pulmonary tuberculosis, both of which are characterized by upper lobe cavities. On the other hand, the presence of middle and lower field lesions with centrilobular nodules and bronchiectasis has been noted. We analyzed the clinical feature of these two radiologically different types and identified their prognostic factors.

METHODS

The clinical, laboratory and radiological findings of 273 cases of MAC disease, newly diagnosed during the recent 7 years periods, were investigated. They were radiologically classified into cavitary (Cav) and nodular bronchiectasis (NB) types at the time of diagnosis. The findings of 44 fatal cases were compared with those of the newly diagnosed cases.

RESULTS

A prominent increase in the number of cases was recently found only in females. Low body mass index (BMI) and moderately reduced serum albumin were found at the time of first hospital visit in both newly diagnosed and fatal cases. In the latter, peripheral blood lymphocyte count was slightly decreased, and tuberculin skin test was negative in 57.7% of the cases. Radiologically, Cav type was prevalent in males and NB type in females in the newly diagnosed cases, while in the fatal cases Cav type was frequently found in both males and females. The two radiological patterns did not change during the entire disease course.

CONCLUSION

Cav type in females was one of the pathogenetic factors. Deterioration of cell-mediated immunity may underlie MAC disease.

Tiotropium ameliorates symptoms in patients with chronic airway mucus hypersecretion which is resistant to macrolide therapy

OBJECTIVE

Low-dose, long-term macrolide therapy has been shown to be effective for the treatment of diffuse panbronchiolitis (DPB) and similar disorders in terms of the presence of airway mucus hypersecretion such as bronchiectasis, chronic bronchitis and sinobronchial syndrome. However, there are some patients, especially advanced cases, whose volume of sputum does not decrease sufficiently with macrolide therapy. These patients suffer from copious expectoration. There is currently no effective treatment, and an effective therapy is therefore urgently required. The aim of this study was to clarify whether or not the inhalation of tiotropium improves the symptoms in these cases.

METHODS

Tiotropium (18 microg/day) was administered to patients with DPB and similar disorders with airway mucus hypersecretion who did not respond to macrolide. The symptoms were evaluated by a visual analog scale (VAS) prior to and at 1 and 3 months after tiotropium administration. Radiological and pulmonary function tests were also performed to evaluate the effects of tiotropium.

RESULTS

Thirteen patients (DPB 5, sinobronchial syndrome 5, bronchiectasis 3) were enrolled. The VAS scores were dramatically improved after the introduction of tiotropium. FEV(1) was significantly improved after 3 months of treatment with tiotropium. In contrast, the radiological findings remained unchanged.

CONCLUSION

Tiotropium improved the symptoms of cough, sputum and breathlessness in the macrolide-resistant cases of DPB or similar disorders. These beneficial effects might be due to the suppression of airway secretion through the anticholinergic effect of tiotropium on the submucosal gland, however, the long-term efficiency of this treatment still needs to be further assessed.

Preventive effect of sulfamethoxasole-trimethoprim on Pneumocystis jiroveci pneumonia in patients with interstitial pneumonia

BACKGROUND

Pneumocystis jiroveci pneumonia (PCP) is a potentially fatal complication in interstitial pneumonia patients receiving glucocorticoid therapy. Prophylaxis of PCP during glucocorticoid therapy is an important issue in the treatment of interstitial pneumonia.

OBJECTIVE

We evaluated the prophylactic effect of sulfamethoxasole-trimethoprim (TMP-SMX) in interstitial pneumonia patients receiving glucocorticoids.

METHODS

We retrospectively analyzed 74 interstitial pneumonia patients who received glucocorticoid therapy.

RESULTS

Seven of the 74 patients developed PCP. At the time of diagnosis of PCP, the mean duration of glucocorticoid therapy was 71 days and the mean daily dose of prednisolone was 37 mg. Among the 7 patients, the circulating CD4+ lymphocyte count was 370 /microl on average and it was over 200 /microl in 3 cases. The PCP patients showed a significant reduction of the lymphocyte count at 4 weeks after initiation of steroid therapy. None of the patients who received prophylactic TMP-SMX therapy developed PCP even if the CD4+ lymphocyte count was less than 200 /microl.

CONCLUSION

Interstitial pneumonia patients receiving glucocorticoid therapy can benefit from TMP-SMX prophylaxis against PCP. Development of PCP cannot be ruled out in patients with a CD4+ lymphocyte count of greater than 200 /microl.