The effect of pulmonary fibrosis on survival in patients with hypersensitivity pneumonitis

PURPOSE

To determine the effect of pulmonary fibrosis on survival in an unselected group of patients with hypersensitivity pneumonitis.

METHODS

We identified 72 patients with hypersensitivity pneumonitis confirmed by surgical lung biopsy in the database of the Clinical Interstitial Lung Disease Program at the National Jewish Medical and Research Center. All biopsy specimens were scored according to the presence or absence of fibrosis. Comparisons were made between patients with (fibrotic group) and without (nonfibrotic group) pathologic fibrosis. Vital status was ascertained and Kaplan-Meier curves were plotted. Cox regression analysis was used to determine predictors of survival.

RESULTS

Forty-six patients were classified as fibrotic and 26 as nonfibrotic. Twenty-nine percent had exposure to a bird antigen, 33% had exposure to a microbial antigen, and 38% had unknown exposure. Patients with fibrosis were significantly older, showed greater restrictive lung physiology, and had greater all-cause and respiratory mortality. Median survival in fibrotic patients was 7.1 years, which was significantly less than survival in those without fibrosis. In an age-adjusted regression analysis, antigen class, symptom duration, and lung function had no effect on survival. Only the presence of pathologic fibrosis was predictive of increased mortality (hazard ratio = 6.01; 95% confidence interval: 1.68 to 21.45; P = 0.006).

CONCLUSION

Pulmonary fibrosis is associated with diminished survival in patients with hypersensitivity pneumonitis.

[Current status and measures for lung injuries in cancer treatment]

The current status and measures for anticancer drug-induced lung injury and radiation pneumonia in cancer treatment were reviewed. Interstitial pneumonia induced by anticancer drugs is pathologically classified into the following: chronic interstitial pneumonia (CIP) or nonspecific interstitial pneumonia (NSIP), eosinophlic pneumonia (EP), bronchiolitis obliterans-organizing pneumonia (BOOP), diffuse alveolar damage (DAD), and hypersensitivity pneumonia (HP). In these pulmonary reactions to anticancer drugs, interstitial pneumonia manifested by DAD, which shows the acute or chronic clinical course, presents high mortality rates. Therefore, special care should be taken when DAD develops. Radiation pneumonia has two clinical phases, an acute phase of injury termed radiation pneumonitis, and a chronic phase of injuring termed lung fibrosis. It is usually confined to the irradiated area. On the other hand, sporadic radiation pneumonitis occurring outside the irradiated area has been reported besides classic radiation pneumonitis. Pathologically, it shows lymphocytic alveolitis or BOOP. Although radiation pneumonia has a good prognosis, mortality is rarely observed when lesion spreads outside the irradiated area.

Inhibitory Effect of Nicotine on Experimental Hypersensitivity PneumonitisIn VivoandIn Vitro

The incidence of hypersensitivity pneumonitis (HP) is lower in smokers than in nonsmokers. Because nicotine is immunosuppressive, we hypothesized that it could have a protective effect on HP induction in vivo. HP was induced in mice that were treated with nicotine either intraperitoneally (IP) (0.5 to 2.0 mg/kg/day) or intranasally (IN) (0.025 to 2.0 mg/kg/day). Both IP- and IN-treated animals had fewer bronchoalveolar lavage total cells and lymphocytes and a decreased lung tissue inflammation. IFN-gamma but not interleukin-10 mRNA expression was reduced in lung tissue of 2.0-mg/kg IN-treated animals. To test the effect of nicotine on alveolar macrophages, AMJ2-C11 cells were treated with nicotine and stimulated with lipopolysaccharide or Saccharopolyspora rectivirgula, a causative agent of HP. Nicotine reduced tumor necrosis factor release and tumor necrosis factor, interleukin-10, and IFN-gamma mRNA expression after stimulation and decreased CD80 expression by 55% in lipopolysaccharide-stimulated cells and by 41% in S. rectivirgula-stimulated cells. We conclude that nicotine could be, at least in part, responsible for the protection observed in smokers against HP. The inhibitory effect of nicotine on alveolar macrophages could be one of the mechanisms involved.

[Preliminary study on effect of pentoxifylline in treatment of extrinsic allergic alveolitis]

OBJECTIVES

Pentoxifylline (POF) is a well established drug with haemorrheological properties. Various evidence suggests an additional therapeutic potential in regard to inflammation and immunomodulation. Extrinsic allergic alveolitis (EAA) is a granulomatous disease which is driven by T cell and alveolar macrophage (AM) derived cytokines. To investigate the effects of POF on the production of tumor necrosis factor (TNF) alpha, interleukin (IL)-1beta, IL-6, IL-8, IL-10 and the soluble TNF receptors (sTNFR1 and sTNFR2) from AM in EAA, also in comparison with dexamethasone (DEX).

METHODS

AM from 9 patients with EAA were cultured for 24 h with 10% RPMI medium alone, or with lipopolysaccharide (LPS, 100 micro g/L), and with POF at concentrations of 0.01 mmol/L, 0.1 mmol/L and 1 mmol/L, or with 0.1 mmol/L DEX. Cytokines in the culture supernatants were analysed by ELISA.

RESULTS

POF induced a dose dependent suppression of spontaneous TNFalpha and IL-10 release from AM in EAA (P < 0.001 and P < 0.05). The spontaneous production of other cytokines was unaffected by POF at all tested concentrations. DEX inhibited only the spontaneous release of TNFalpha significantly (P < 0.05). POF and DEX also inhibited the LPS-stimulated production of all cytokines except of IL-1beta and sTNFR1 (P < 0.001 or P < 0.01 or P < 0.05).

CONCLUSION

Our results may be the basis for clinical trials to evaluate the role of POF as an immunotherapeutic agent in the treatment of EAA.

Chemokine production during hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is an interstitial lung disease that develops following repeated exposure to inhaled particulate antigens. Individuals with HP develop lymphocytic alveolitis,granuloma formation, and fibrosis. HP is categorized as a Th1 disease, and granuloma formation is dependent on T cells and the Th1 cytokine IFN-gamma. We therefore hypothesized that the IFN-gamma-inducible chemokines IP-10, Mig, and I-TAC, which are frequently associated with Th1 diseases, would play an important role in the pathogenesis of disease. We analyzed the expression of multiple chemokines in the lungs of wild-type (WT) and IFN-gamma-knockout (GKO) mice exposed to the particulate antigen Saccharopolyspora rectivirgula (SR). Our results demonstrate the production of IP-10, Mig, and I-TAC in WT mice during the development of HP, whereas GKO mice have reduced levels of IP-10 and no Mig or I-TAC mRNA in the lungs in response to SR exposure. The production of these chemokines is associated with an influx of CXCR3+/CD4+ T cells into lungs of WT mice, which is reduced in GKO mice. These results suggest that IFN-gamma mediates the recruitment of CXCR3+/CD4+ T cells into the lung via production of the chemokines IP-10, Mig, and I-TAC, resulting in granuloma formation.

T cells in the lung of patients with hypersensitivity pneumonitis accumulate in a clonal manner

Hypersensitivity pneumonitis (HP) is characterized by an alveolitis sustained by CD8(+) T lymphocytes showing a limited expression of the T cell receptor (TCR). We previously demonstrated that a bias in T cell selection occurs in the lower respiratory tract of patients with HP, with a compartmentalization in the lung of CD8(+) T cells bearing (TCR)-beta variable (TCRBV) #2, 3, 5, 6, 8, and 13 gene segments. We herein characterized the clonal T cell populations present in the lung and in the blood of patients with HP. Heteroduplex analyses, cloning, and sequencing T cells bearing TCR indicate oligoclonal expansions of T cells expressing homologous or identical complementary-determining region 3. Furthermore, T cell clones isolated from the two compartments expressed similar, sometimes identical, junctional regions. Removal from antigenic exposure led to the disappearance of T cell clones. Our findings indicate that expansions of T lymphocytes bearing clonal TCRBV region gene segments take place in the lung of patients with HP during exposure. The evidence that identical T cell clones are present in the lung and the blood of the same patient suggests that the immune reaction occurring at lung level gives rise to a systemic reaction.

Uniportal VATS wedge pulmonary resections

Since 2000, 15 patients have undergone single port (uniportal) video-assisted thoracic surgery for wedge pulmonary resection either for diagnosis of interstitial lung diseases (10 patients) or for treatment of primary spontaneous pneumothoraces (5 patients). Diagnosis was obtained in all patients and no recurrences of pneumothorax were seen at follow-up. This initial experience shows that, for specific indications, uniportal video-assisted thoracic surgery for wedge pulmonary resections can be safe and effective.

Expression of the thioredoxin system in interstitial lung disease

The thioredoxin system containing thioredoxin (Trx) and thioredoxin reductase (TrxR) has profound effects on cell proliferation and protection against exogenous oxidants. The significance of the Trx system in human lung and lung diseases is, however, largely unresolved. Altogether, 66 specimens of human lung were investigated by immunohistochemistry for their expression of Trx and TrxR. The diseases included interstitial pneumonias such as usual interstitial pneumonia (UIP), desquamative interstitial pneumonia (DIP), and UIP associated with collagen vascular diseases (CVD-ILD), and granulomatous diseases such as sarcoidosis and allergic alveolitis. The ultrastructural localization of Trx and TrxR was analysed by immunoelectron microscopy. In healthy lung, Trx and TrxR were expressed in bronchial epithelium and alveolar macrophages. Trx and TrxR were highly concentrated in areas of metaplastic epithelium in UIP and in alveolar macrophages in DIP, though fibrotic areas in UIP were mainly negative. The expression of both enzymes was clearly weaker in CVD-ILD than in UIP. Granulomas of sarcoidosis showed moderate to intense Trx immunoreactivity. Ultrastructurally, Trx and TrxR were expressed diffusely in the cytosolic compartment and plasma membrane of metaplastic type II pneumocytes, macrophages, and bronchial epithelial cells. This study highlights the importance of Trx and TrxR in primary defence in bronchial epithelium, alveolar epithelium, and macrophages in human lung, but also indicates that elevated expression of these proteins may serve as markers of ongoing cell regeneration and inflammation.

[Hypersensitivity pneumonitis recognised by open lung biopsy in patients at the Institute of Tuberculosis and Lung Diseases]

Diagnosis of hypersensitivity pneumonitis (HP) is made on the basis of a combination of clinical features connected with the exposition to organic dusts, radiographic abnormalities, lung function tests and immunological tests. Open lung biopsy (OLB) and histological examination is not necessary and is indicated mainly in chronic and subacute form of HP. In the chronic form of HP symptoms often do not show a temporal relationship with antigen exposure and errors occur especially if specific questions are not asked about exposure to antigen if HP. The aim of this paper was to analyse whether OLB was necessary in all patients in whom HP was recognised just after this procedure. Material included 21 patients in whom microscopic examination suggested HP among 258 pts in whom OLB was performed in the period of 1998-2003. There were 13 men and 8 women at the age of 18 to 65 years, mediana 42 years.

RESULTS

We found 3 groups of pts. Group "+" included 9 exposed pts. They were asked and confirmed contact with birds, hay and 7 of them observed correlation between exposition and symptoms. The second Group "-" included 7 pts who were asked about exposition and who answered in the negative. In all of them HRCT scans suggested HP. Restriction was below 70% of VC in 3 pts. The third Group "0" included 5 pts who were not asked about exposition and correlation with symptoms. Two from them lived in the rural area.

CONCLUSIONS

Open lung biopsy was not necessary for 6 patients in Group "+", because then had enough symptoms to recognise HP. In 3 patients of Group "+" and in 5 of Group "0" OLB could be not necessary because specific anamnesis and additional examinations were not collected. OLB was necessary method for 7 patients in Group "-".

Suberosis and bird fancier's disease: a comparative study of radiological, functional and bronchoalveolar lavage profiles

Hypersensitivity Pneumonitis (HP) is an immunologically mediated interstitial lung disease that may result from repeated inhalation of many different environmental agents. Heterogeneity of the clinical presentation and bronchoalveolar lavage profiles have been described, possibly related to different occupational exposures. The aim of our study was to compare bronchoalveolar lavage fluid (BALF), clinical, functional and radiological characteristics of the two most frequent forms of HP seen in our practice: Suberosis (an HP related to moldy cork dust exposure) and bird fancier's disease (BFD). We included 81 patients with Suberosis, with a mean age of 38.8 +/- 11.3 years and a mean exposure of 20.0 +/- 10.5 years and 32 patients with BFD, with a mean age of 46.3 +/- 11.8 years and mean exposure of 10.5 +/- 1.0 years. Patients with BFD had more acute forms, while subacute and chronic presentations predominated in Suberosis. Restrictive defect was the most frequent pattern of lung function impairment, and more severe in BFD. Ground glass opacities were the most frequent pattern in high-resolution computed tomography. A normal chest x-ray was more frequently seen in Suberosis. Both types of HP had lymphocytic alveolitis in BALF: Suberosis - 6.6 +/- 5.7 x 10(5) ml-l cells, 58.8 +/- 18.9% lymphocytes; bird fancier's disease - 9.0 +/- 6.5 x 105 ml-l cells, 61.7 +/- 22.2% lymphocytes. Although BALF CD8+ lymphocytes predominated in both diseases, the proportion of CD4+ and CD4/CD8 ratios were significantly higher in bird fancier's disease (Suberosis: 0.47 +/- 0.33 versus BFD: 1.1 +/- 1.5; p < 0.005). Moreover, BALF cellularity and mast cell counts were also significantly higher in BFD. In conclusion, Suberosis and bird fancier's disease are HP with different clinical and laboratory profiles, suggesting that despite their pathophysiological similarities, different antigenic exposures may cause different immune and inflammatory response dynamics in the lung.

Angiogenesis in hypersensitivity pneumonitis

Angiogenesis is an essential process required for growth and tissue repair after injury, but it may also contribute to the pathology of a number of human disorders including neoplasias, atherosclerosis and inflammatory diseases. Vascular endothelial growth factor (VEGF) is a potent angiogenic peptide upregulated by many cytokines and endothelium shear stresses. Lung is a highly vascular tissue with finely organized and regulated microvascular beds, and its inflammation may lead to dysregulated angiogenesis. Hypersensitivity pneumonitis (HP) is a lung disorder characterized by chronic lymphocytic inflammation and endothelial damage. However, neovascularization has not been previously explored. In this study, we examined the expression and localization of VEGF in 38 patients with HP and 14 healthy control subjects (CS). VEGF levels in bronchoalveolar lavage fluid (BALF) were measured by ELISA, and cellular lung localization was determined by immunohistochemistry. In addition, VEGF expression was analyzed in lung tissue by RT-PCR. Our results showed sera levels significantly increased in HP patients compared with CS (209.3 +/- 189.3 vs. 55.3 +/- 31.4 pg/ml; p = 0.004). By contrast, BALF levels of VEGF were significantly decreased in HP patients compared with CS (35.3 +/- 51.5 pg/ml vs. 185.1 +/- 191.4 pg/ml; p < 0.001). VEGF was primary expressed by epithelial cells, smooth muscle cells, and interstitial macrophages in HP tissue. Flt-1 and Flk-1 receptors were highly expressed by endothelial cells from medium and small vessels in HP tissue. By RT-PCR the VEGF RNA was increased compared with those in normal lung. Our results suggest that abnormal expression of VEGF may contribute to impair the lung repair in HP.

[Cytomorphologic changes detected in bronchial biopsy specimens in patients with alveolitis]

Eighty-nine patients with alveolitis were followed up. Of them, 60 patients had exogenous allergic alveolitis (EAA) and 29 had idiopathic fibrosing alveolitis (IFA). Transbronchial lung biopsy (TLB) proved to be the most informative method for alveolitis. At the same time a cytomorphologic study of TLB specimens revealed exogenous allergic alveolitis in all phases of the disease in 91.2% of the cases. In idiopathic fibrosing alveolitis, the informative value of TLB was 59.7%.

Hypersensitivity pneumonitis. High resolution CT findings with pathological correlations. A pictorial essay

The diagnosis of HP is based upon the association of antigen exposure history, compatible clinical and radiological findings and high titres of precipitating serum antibodies to specific antigens. The manifestations of HP are usually divided into three typesacute, sub-acute and chronicbut a significant overlap exists. The clinical spectrum probably reflects different factors, specific to the subject, as well as the frequency and degree of exposure. The aim of this pictorial essay is to present the more common presentations of HP.

[Hypersensitivity pneumonitis induced in guinea pigs by antigens to bat feces]

A bat feces extract was able to induce the synthesis of specific IgG in rabbits and IgE in atopics. These findings were corroborated by skin tests, RAST and RAST-inhibition. Nowadays, data concerning the experimental induction of hypersensitivity pneumonitis using a glycoprotein of bat feces are presented. This antigen was aerosolized for inhalation by adult guinea pigs for 12 weeks to detect specific serum IgM, IgG and IgE antibodies as well as sensitized T-CD4 cells. Histopathological studies of the lungs showed interstitial infiltrates of macrophages and lymphocytes, cellular bronchiolitis and single non-necrotizing granulomas from the seventh to the ninth weeks. From the tenth week to the end of the experiment the lesions of the lungs progressively worsened. The results from this animal model suggest that the chronic contact with the bat feces'antigen can induce other inflammatory lung reactions than those IgE dependant.

Thrombin-activatable fibrinolysis inhibitor and protein C inhibitor in interstitial lung disease

Intraalveolar activation of the coagulation system due to reduced fibrinolytic function plays a critical role in the pathogenesis of interstitial lung disease. Recently, a new potent inhibitor of fibrinolysis, thrombin-activatable fibrinolysis inhibitor, has been isolated and characterized from human plasma. This study evaluated the levels of thrombin-activatable fibrinolysis inhibitor and protein C inhibitor, another suppressor of fibrinolysis, in the bronchoalveolar lavage fluid from patients with interstitial lung disease. There were 82 patients with interstitial lung disease and 8 normal subjects. The bronchoalveolar lavage fluid levels of thrombin-activatable fibrinolysis inhibitor and protein C inhibitor were significantly higher in all patients with interstitial lung disease than in normal subjects. Both inhibitors of fibrinolysis were significantly and inversely correlated with fibrinolytic activity in all patients. The levels of thrombin-activatable fibrinolysis inhibitor were significantly correlated with those of protein C inhibitor, thrombin-antithrombin complex, and monocyte chemoattractant protein-1. Reverse transcriptase-polymerase chain reaction showed that alveolar macrophages isolated from patients with interstitial lung disease as well as immortalized lung epithelial cell lines express thrombin-activatable fibrinolysis inhibitor antigen. Overall, these findings suggest that thrombin-activatable fibrinolysis inhibitor and protein C inhibitor may play important roles in the mechanism of intraalveolar hypofibrinolysis associated with interstitial lung diseases.

[Comparison of cellular composition of induced sputum, bronchial washings and bronchoalveolar lavage fluid in sarcoidosis, hypersensitivity pneumonitis and COPD]

This study compares the cellular profiles of induced sputum (IS), bronchial washing (BW), and BAL fluid (BAL) in newly diagnosed sarcoidosis (BBS) and hypersensitivity pneumonitis (HP) patients to COPD group, and examines whether inflammatory cell counts from IS correlated with inflammatory cell counts from BW and BAL in sarcoidosis and HP patients.

METHODS

We recruited 23 untreated patients with stage II pulmonary sarcoidosis, 15 untreated patients with HP and 17 COPD patients. Sputum was induced with hypertonic saline solution in all individuals. Bronchoscopy was performed on a different occasions in all patients.

RESULTS

Mean lymphocyte counts in IS, BW, and BAL fluid from sarcoidosis and HP patients were significantly higher than in COPD subjects (8.9% and 13.8 vs 2.9%, p < 0.05; 11.9% and 30.5 vs 3.2%, p < 0.05; 21.5% and 56 vs 3.4%, p < 0.05, respectively). Moreover we found higher percentage of CD4+, CD3+ CD28+, CD3+ HLADRV+, and gamma delta T cells in IS, BW, and BAL fluid from both BBS and HP groups than in from COPD. Elevated CD4/CD8 ratio characterized IS, BW and BAL fluid in BBS group. Strong correlation IS/BAL and IS/BW of CD3+ CD28+, CD3+ HLADRV+, and CD4/CD8 ratio was found.

CONCLUSIONS

We demonstrated that, although the relative proportion of inflammatory cells differed in the three samples, lymphocyte counts in IS were high. This finding suggests that IS could be used as a valuable alternative method to more conventional invasive techniques in clinical assessment of interstitial lung diseases patients.

[Biochemical characteristics of fluid and cells of bronchoalveolar washings in patients with extrinsic allergic alveolitis]

In 43 patients with exogenous allergic alveolitis (EAA), including 30 and 13 in its acute and chronic disease, bronchoalveolar lavage was performed, bronchoalveolar washing fluid (BAWF), isolated alveolar macrophages (AM) and unfractionated cellular sediment (NFCS) were separately studied. The BAWF showed high rates of lipid peroxidation (LPO), decreased antiproteolytic defense, and activated local synthesis of haptoglobin (Hp), fibronectin (FN), platelet activation factor (PAF), and enzymes of antioxidative defense (AOD). There was a rise in FN and PAF concentrations in the acute phase of the disease and higher PLO rates and elevated Hp levels in chronic EAA. The rate of oxidative metabolism in AMs was much higher in acute EAA than that in chronic EAA and accompanied by imbalance in the PLO-AOD system. AM levels of PAF was high in patients in both groups. The rate of LPO was higher in NFCS than in AM and was also followed by simultaneous AOD mobilization with preserved imbalance. A particularly significant AOD insufficiency in the NFCS was noted in chronic EAA, which was accompanied by decreased PAF. Thus, local pathochemical processes are of significance in developing the pattern of the process in EAA.

Apoptosis of bronchoalveolar lavage lymphocytes in hypersensitivity pneumonitis

The aim of this study was to look at the apoptosis of alveolar lymphocytes in hypersensitivity pneumonitis (HP). HP patients and normal unexposed controls were studied. The percentage of apoptotic lymphocytes was significantly lower in HP patients than in normal patients (37.4 +/- 3.4 versus 56.5 +/- 5.5% for Annexin V and propidium iodine detection methods and 0.4 +/- 0.1 versus 1.0 +/- 0.2% for dUTP nick end-labelling technique (TUNEL)). The proportion of bronchoalveolar lavage (BAL) lymphocytes positive for Fas antigen was significantly higher in HP patients than in normal subjects (71.7 +/- 5.4 versus 50.4 +/- 9.0%). However, no significant difference was found in the proportion of BAL lymphocytes positive for Fas ligand (FasL) between the two groups. Soluble Fas (sFas) levels in the BAL fluid of the patients and normals were 80.5 +/- 8.5 pg x mL(-1) and 23.2 +/- 3.1 pg x mL(-1), respectively. A positive correlation was found between the percentage of BAL lymphocytes and the levels of sFas for the total subjects but not within the separate study groups. The intracellular quantity of the inducible anti-apoptotic gene Bcl-xL product was significantly higher in the pulmonary lymphocytes of HP patients than in lymphocytes of the control, while no difference was found for constitutive anti-apoptotic protein (Bcl-2). In conclusion, the apoptosis of pulmonary lymphocytes is lower in hypersensitivity pneumonitis than in normal subjects. This could be explained, at least in part, by an increase of soluble Fas, the anti-apoptic gene, and Bcl-xL.

Clinicopathological features of chronic hypersensitivity pneumonitis

OBJECTIVE

Only limited information exists concerning the clinical and pathological features of chronic hypersensitivity pneumonitis (HP) in Japan and elsewhere. We present data on clinicopathological features of chronic HP obtained through a Japanese nationwide survey.

METHODOLOGY

We studied the clinical and pathological findings in 10 patients with chronic HP who underwent surgical lung biopsy or postmortem examination.

RESULTS

There were three types of clinical course: six of the 10 patients had persistent symptoms followed by repeated acute episodes; two showed a subacute onset with persistent symptoms; and two exhibited an insidious onset. Five patients made no attempt to avoid antigen exposure and they all had progressive disease. Pathological findings indicated that lesions were mainly centrilobular with or without epithelioid cell granulomas in specimens obtained during the acute or subacute stage. In contrast, most patients in the chronic stage predominantly showed interstitial fibrosis with a usual interstitial pneumonia pattern.

CONCLUSIONS

The pathological findings of chronic HP depend on the stage of the disease at tissue sampling.

Hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a group of immunologically mediated lung diseases caused by the inhalation of environmental agents in susceptible individuals. Most HP patients are non-smokers and have been exposed to organic dusts from vegetable or animal products. Some HP cases are associated with exposures to relatively simple chemical compounds. HP may present as an acute, subacute, or chronic disease and may follow various clinical courses. The type of exposure is thought to be more important in the clinical outcome than the nature of the antigen. A diagnosis of HP is often considered on the basis of clinical history of exposure with resulting respiratory symptoms, but the definitive diagnosis requires a constellation of clinical, radiologic, laboratory, and pathologic findings. The characteristic histologic triad in HP includes bronchiolitis, interstitial lymphocytic infiltration, and granulomas; however, biopsy in HP cases may lack the diagnostic triad and manifest as nonspecific interstitial pneumonia (NSIP). Avoiding exposure to the offending antigen(s) is usually sufficient to resolve symptoms and physiological abnormalities. Pulmonary fibrosis and physiological abnormalities occurring in chronic HP may be irreversible. Steroid therapy is helpful for symptomatic relief, but probably does not affect the long-term prognosis. Type III and type IV hypersensitivity reactions are involved in the pathogenesis; alveolar macrophages and T cells (Th-1 type) play a central role in the immune responses after antigen exposure via their increased interaction and secretion of regulatory mediators.

Microbial cell wall product contamination of bedding may induce pulmonary inflammation in rats

To test the hypothesis that airborne microbial cell wall components could induce an inflammatory response in the lungs, measurements were made of the amounts of bacterial endotoxin and (1-->3)-beta-D-glucan in laboratory animal bedding materials. Groups of rats were exposed by inhalation to airborne endotoxin, (1-->3)-beta-D-glucan or a combination of the two for 5 weeks. The results demonstrated that measurable amounts of endotoxin and (1-->3)-beta-D-glucan could be detected in the different bedding materials. In contrast to animals at delivery, those kept on bedding for 5 weeks showed moderate inflammatory reactions in the lung. These were most pronounced among animals exposed to endotoxin and (1-->3)-beta-D-glucan. The results suggest that further studies need to be undertaken to elucidate the role of microbial cell wall products in the development of inflammatory lung responses among research animals.

Hypersensitivity pneumonitis in children

Hypersensitivity pneumonitis in children is an underrecognized form of immune-mediated interstitial lung disease that results from repeated exposure to the inhalation of organic antigens. Because overt disease develops in only a small percentage of exposed individuals, complex interactions between the nature of the antigen, the intensity and duration of the exposure, and the host response in susceptible individuals are most likely involved. In most reported pediatric cases, hypersensitivity pneumonitis results from exposure to avian antigens, but it has also been seen with exposure to molds and methotrexate. The diagnosis is established by documented exposure, compatible clinical presentation, and consistent radiologic features; it is supported by positive precipitating antibodies, lymphocytosis in bronchoalveolar lavage fluid, and characteristic histologic changes on lung biopsy. Treatment consists of antigen avoidance in all cases, and corticosteroids in severe cases. The prognosis is excellent when prompt recognition and treatment are initiated.

[A case of loxoprofen-induced pneumonitis pathologically resembling hypersensitivity pneumonitis]

A 66-year-old woman was admitted to our hospital because of high fever, general fatigue, hypoxemia and liver dysfunction. Chest radiographs showed diffuse interstitial shadows in both lungs. We suspected drug-induced pneumonitis because of her history of drug administration for upper respiratory infection. Her symptoms and findings were markedly decreased by discontinuation of the drugs. Transbronchial lung biopsy specimens showed infiltration of eosinophils and lymphocytes to the alveolar septa, granuloma with Langhans' giant cells, and Masson bodies in a manner suggestive of hypersensitivity pneumonitis. Drug lymphocyte stimulation tests were negative except for loxoprofen. There was no recurrence of systemic or respiratory symptoms during overnight stays at home. On the basis of these findings, we arrived at a diagnosis of drug-induced pneumonitis caused by loxoprofen.

Haemorrhagic hypersensitivity pneumonitis due to naphthylene-1,5-diisocyanate

Symptoms of hypersensitivity pneumonitis and massive pulmonary haemorrhage occurred in a 24-yr-old male shortly after occupational exposure to naphthylene-1,5-diisocyanate (NDI). The present examination was performed approximately 1-yr after the initial life-threatening haemoptysis and following an uneventful recovery after resection of the middle lobe, which had been identified bronchoscopically as the bleeding source. Histological re-examination of the lung was compatible with hypersensitivity pneumonitis. After a chamber challenge with NDI (5 parts per billion (ppb) for 10 min, 10 ppb for 110 min), rales were heard in both lungs, and a fall in vital capacity and partial pressure of arterial oxygen as well as a rise in body temperature were documented. Isocyanate-specific immunoglobulin-G antibodies could not be detected in the patient's serum, possibly due to the long period without exposure to isocyanates. The authors conclude that naphthylene-1,5-diisocyanate may cause immunological pulmonary haemorrhage. The underlying disease is consistent with hypersensitivity pneumonitis and may be triggered by low concentrations of the diisocyanate.

Expression of adhesion molecules in allergic lung diseases

Endothelial adherence and migration of leukocytes into tissue is mediated by different sets of adhesion molecules. The expression of these sets might not only preselect the types of leukocytes that enter the inflammatory sites, but also activate these leukocytes, induce adherence to epithelial cells, and cause the release of cytokines. Atopic asthma, extrinsic allergic alveolitis, and sarcoidosis as examples of immunologic lung diseases were investigated for the expression of adhesion molecules. Bronchial biopsies in chronic obstructive lung disease (COPD) and resected lung tissue of juvenile emphysema were chosen for controls. Immunohistochemistry was done on sections from bronchial and transbronchial biopsies and on smears from bronchoalveolar lavage cells. In all three types of immune disorders, lymphocytes expressed the integrins alpha4/beta1 (VLA4) and ICAM3, whereas lymphocytes in COPD bronchitis and in emphysema controls were unreactive. Eosinophils in atopic asthma bronchitis in contrast to COPD bronchitis also expressed both VLA4 and ICAM3. The expression of VCAM1 on endothelial cells was only seen in atopic asthma and was related to disease activity. The expression of other adhesion molecules was nonspecific. Expression of VCAM1 on endothelial cells and its ligand VLA4 on lymphocytes and eosinophils seems to be a specific event in atopic asthma. Expression of VLA4 and ICAM3 on lymphocytes, however, might be a specific event in all three immune reactions.

[Morphological diagnosis of tuberculosis and some disseminated diseases of the lungs]

Based on the results of light optic and electron microscopic studies of lung tissue biopsy specimens from patients with disseminated tuberculosis (n = 31), sarcoidosis (n = 46), exogenous allergic alveolitis (n = 22), the authors present a set of various morphological signs of specific inflammation, which are detectable both in the area of a focus and in its adjacent sites. The set allows the diagnosis of the most common granulomatoses of the lung to be verified.

High-resolution CT in the evaluation of occupational and environmental disease

The most common of the pneumoconioses are silicosis, CWP, and asbestosis. The former two are characterized by the presence of small nodular opacities predominantly distributed in the upper zones of the lung. The small nodular opacities are classified into two patterns on HRCT: (1) ill-defined fine branching lines and (2) well-defined discrete nodules. Asbestosis demonstrates thickened interlobular and intralobular lines, subpleural dot-like or curvilinear opacities, and honeycombing on HRCT, predominantly distributed in the bases of the lungs. Although HRCT findings of other pneumoconioses are variable and nonspecific, there are predominant and characteristic findings for each type of pneumoconiosis. HRCT is useful in achieving more accurate categorization of the parenchymal changes in each type of pneumoconiosis.

Inducible nitric oxide synthase, but not xanthine oxidase, is highly expressed in interstitial pneumonias and granulomatous diseases of human lung

We assessed the distribution and expression of inducible nitric oxide synthase (i-NOS), endothelial nitric oxide synthase (e-NOS), and xanthine oxidase (XAO) in usual interstitial pneumonia, desquamative interstitial pneumonia, and granulomatous diseases. The material consisted of biopsy specimens from 5 healthy subjects (nonsmokers), 9 patients with usual interstitial pneumonia, 11 with desquamative interstitial pneumonia, 14 with sarcoidosis, and 8 with extrinsic allergic alveolitis. i-NOS was expressed intensively in inflammatory but not infibrotic lesions. It was expressed most prominently in alveolar macrophages and alveolar epithelium of all disorders and in the granulomas of sarcoidosis and extrinsic allergic alveolitis. In contrast with i-NOS, e-NOS was expressed prominently in control lung tissue samples but also in granulomas of sarcoidosis and extrinsic allergic alveolitis. Reverse transcription-polymerase chain reaction performed on bronchoalveolar lavage fluid samples from patients with sarcoidosis or usual interstitial pneumonia andfrom healthy subjects indicated positivity for XAO, but immunohistochemical analysis in samples from healthy lung and all parenchymal lung disorders showed no immunoreactivity for XAO. i-NOS has an important role in the pathogenesis of interstitial lung diseases, being up-regulated during the inflammatory but not during the fibrotic disease stage.

Chronic hypersensitivity pneumonitis induced by Shiitake mushroom spores associated with lung cancer

A 61-year-old man was admitted to our hospital with a 6-month history of productive cough. He, along with his wife, had been involved with Shiitake mushroom cultures for a period of 12 years. On admission, chest radiography showed bilateral fine-nodular shadow and CT scans showed reticulonodular opacities and a ground-glass appearance predominantly in the subpleural area in both lungs, and a mass in the left S6. Resected pathological specimens obtained by left lower lobectomy revealed lung adenosquamous carcinoma (stage IB), interstitial changes accompanied with lymphocyte proliferation and fibrosis, and granuloma with giant cells. Serum precipitins for Shiitake mushroom antigens were positive. The productive cough improved after the hospital admission and occurred again when he returned to work with the Shiitake mushroom production. Therefore, chronic hypersensitivity pneumonitis (HP) caused by Shiitake mushroom spores was diagnosed. Moreover, his wife was found to have HP caused by mushrooms at this time. There are only two previous reports of chronic HP caused by Shiitake mushroom in Japan, and this is the first case of chronic HP associated with lung cancer.

Hypersensitivity pneumonitis induced by spores of Lyophyllum aggregatum

OBJECTIVES

Lyophyllum aggregatum (LA) is called Shimeji in Japanese and is eaten commonly as a mushroom. Shimeji mushrooms are cultivated in an indoor environment all year round. This study aimed to clarify the clinical features of hypersensitivity pneumonitis (HP) induced by LA.

PATIENTS AND SETTING

Ten patients showed mild respiratory symptoms including dry cough, sputum, and low-grade fever. We tried to characterize the clinical features and the findings using chest high-resolution CT (HRCT), pulmonary function tests (PFTs), and BAL fluid (BALF) tests in patients with HP induced by LA. HP was diagnosed from clinical features, HRCT findings, BALF findings, lung histology, and lymphocyte stimulation tests (LSTs) for LA.

RESULTS

Laboratory findings showed mean (+/- SD) elevated levels of C-reactive protein (0.78 +/- 1.3 mg/dL), erythrocyte sedimentation rate (48 +/- 23 mm/h), and gamma-globulin (26.9 +/- 7.6%). PFTs revealed a slight decrease in the percentage diffusing capacity of the lung for carbon monoxide, possibly due to the presence of epithelial granulomas in the alveoli. Although 4 of 10 patients showed normal findings on the chest radiograph (CXR), chest HRCT findings of all patients showed centrilobular small nodules and diffuse ground-glass opacities. The BALF testing revealed an increase in total cell counts, showing predominantly activated T lymphocytes. The CD4/CD8 cell ratio was significantly decreased (0.5 +/- 0.3). The results of the LSTs were positive in seven of seven cases.

CONCLUSIONS

Since patients with HP induced by LA typically have mild respiratory symptoms and sometimes normal CXR findings, their conditions might remain undiagnosed. However, the chest HRCT images showed the typical subacute phase of HP.

CCL18/DC-CK-1/PARC up-regulation in hypersensitivity pneumonitis

Hypersensitivity pneumonitis (HP) is a lung inflammatory disorder characterized by accumulation of T lymphocytes. However, the mechanisms implicated in this process remain undefined. We examined the expression of dendritic cell (DC)-derived CC chemokine 1 (CK1)/CCL18, a chemokine putatively involved in naive T cell recruitment, in lungs from 10 patients with HP, 9 patients with idiopathic pulmonary fibrosis (IPF), and 20 healthy lungs. CCL18 was measured by real-time quantitative PCR and localized in lungs by in situ hybridization and immunohistochemistry. CCL18 expression was significantly increased in lungs affected by HP in comparison with lungs affected by IPF (2,085+/-393 vs. 1,023+/-110; P<0.05) and controls (2,085+/-393 vs. 467+/-94; P<0.01). Macrophages, DCs, and alveolar epithelial cells were the main sources of CCL18. There was a direct correlation between the levels of tissue CCL18 and the number of lymphocytes in the bronchoalveolar lavage fluids. High levels of CCL18 were detected in the subacute rather than the chronic phase of HP. These findings suggest a role for CCL18 in the pathogenesis of HP.

Computer program supporting the diagnostic accuracy of cellular BALF analysis: a new release

Recently we developed a validated computer program based on polychotomous logistic regression analysis using bronchoalveolar avage fluid (BALF) results to distinguish between the three most common interstitial lung diseases (ILD): sarcoidosis, idiopathic pulmonary fibrosis (IPF) and extrinsic allergic alveolitis (EAA) or drug-induced pneumonitis. One of the limitations of this program was that it was not useful in discriminating between infectious disorders and non-infectious disorders. Therefore, we added BALF samples obtained from patients with a confirmed bacterial pulmonary infection based on culture results > or = 10(4) cfum l(-1) (group I: n=31) to the study population mentioned above (group II: n=272). Notably, just one variable, i.e. the percentage of polymorphonuclear neutrophils, allowed us to distinguish between infectious and non-infectious disorders. The agreement of predicted with the actual diagnostic group membership was 99.67% (groups I and II). Additionally, 91.2% of the cases with ILD were correctly classified. In conclusion, this updated Windows version 2000 of the validated computer program provides a very reliable prediction of the correct diagnosis for an arbitrary patient with suspected pneumonia or with ILD given information obtained from BALF analysis results, and is thought to improve the diagnostic power of BALF analysis.

Extended exhaled NO measurement differentiates between alveolar and bronchial inflammation

Lower respiratory tract inflammation can be detected by measuring exhaled nitric oxide (NO) concentration at a single exhalation flow rate, but this does not differentiate between alveolar and bronchial NO production. We assessed alveolar NO concentration and bronchial NO flux with an extended method of measuring exhaled NO at several exhalation flow rates in 40 patients with asthma, 17 patients with alveolitis, and 57 healthy control subjects. Bronchial NO flux was higher in asthma (2.5 +/- 0.3 nl/s, p < 0.001) than in alveolitis (0.7 +/- 0.1 nl/s) and healthy control subjects (0.7 +/- 0.1 nl/s). Alveolar NO concentration was higher in alveolitis (4.1 +/- 0.3 ppb, p < 0.001) than in asthma (1.1 +/- 0.2 ppb) and healthy control subjects (1.1 +/- 0.1 ppb). In asthma, bronchial NO flux correlated with serum level of eosinophil protein X (EPX) (r = 0.60, p < 0.001) and bronchial hyperresponsiveness (r = 0.55, p < 0.001). In alveolitis, alveolar NO concentration correlated inversely with pulmonary diffusing capacity (r = -0.55, p = 0.022) and pulmonary restriction. Glucocorticoid treatment or allergen avoidance normalized bronchial NO flux in asthma and decreased alveolar NO concentration toward normal in alveolitis. In conclusion, extended exhaled NO measurement can be used to separately assess alveolar and bronchial inflammation and to assess disease activity/severity in asthma and alveolitis.

Regulatory effects of eotaxin on acute lung inflammatory injury

Eotaxin, which is a major mediator for eosinophil recruitment into lung, has regulatory effects on neutrophil-dependent acute inflammatory injury triggered by intrapulmonary deposition of IgG immune complexes in rats. In this model, eotaxin mRNA and protein were up-regulated during the inflammatory response, resulting in eotaxin protein expression in alveolar macrophages and in alveolar epithelial cells. Ab-induced blockade of eotaxin in vivo caused enhanced NF-kappaB activation in lung, substantial increases in bronchoalveolar lavage levels of macrophage inflammatory protein (MIP)-2 and cytokine-induced neutrophil chemoattractant (CINC), and increased MIP-2 and CINC mRNA expression in alveolar macrophages. In contrast, TNF-alpha levels were unaffected, and IL-10 levels fell. Under these experimental conditions, lung neutrophil accumulation was significantly increased, and vascular injury, as reflected by extravascular leak of (125)I-albumin, was enhanced. Conversely, when recombinant eotaxin was administered in the same inflammatory model of lung injury, bronchoalveolar lavage levels of MIP-2 were reduced, as was neutrophil accumulation and the intensity of lung injury. In vitro stimulation of rat alveolar macrophages with IgG immune complexes greatly increased expression of mRNA and protein for MIP-2, CINC, MIP-1alpha, MIP-1beta, TNF-alpha, and IL-1beta. In the copresence of eotaxin, the increased levels of MIP-2 and CINC mRNAs were markedly diminished, whereas MIP-1alpha, MIP-1beta, TNF-alpha, and IL-1beta expression of mRNA and protein was not affected. These data suggest that endogenous eotaxin, which is expressed during the acute lung inflammatory response, plays a regulatory role in neutrophil recruitment into lung and the ensuing inflammatory damage.

Fc gamma RIII-mediated production of TNF-alpha induces immune complex alveolitis independently of CXC chemokine generation

We recently demonstrated a codominant role of C5aR and FcgammaRIII in the initiation of IgG immune complex-mediated inflammation in mice. In this study, we investigated the relative contribution of FcgammaRIII in the generation of several cytokines during experimental hypersensitivity pneumonitis/alveolitis in vivo. Induction of immune complex-alveolitis in C57BL/6 mice resulted in strong accumulation of neutrophils into the lung and enhanced chemotactic activity within bronchoalveolar lavage fluid accompanied by an increased production of the proinflammatory cytokines TNF-alpha and IL-1beta as well as the ELR-CXC chemokines macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (KC). FcgammaRIII-deficient C57BL/6 mice (FcgammaRIII(-/-)) showed a marked reduction of the inflammatory response due to decreased production of TNF-alpha, IL-1beta, and MIP-2. Results obtained in C57BL/6 mice either lacking the TNF-alpha class I receptor (TNF-alphaRI(-/-)) or treated with neutralizing anti-TNF-alpha mAb demonstrated an essential contribution of TNF-alpha for mediating IL-1beta release, neutrophil influx, and hemorrhage. Surprisingly, MIP-2 and KC chemokine levels remained largely unaffected in TNF-alphaRI(-/-) mice or after functional inhibition of TNF-alpha. These data suggest that in immune complex alveolitis, the activation of FcgammaRIII may induce divergent downstream effector pathways with TNF-alpha acting independently of CXC chemokines to trigger the inflammatory response in C57BL/6 mice.

[A case of chronic hypersensitivity pneumonitis due to wild pigeons]

A 61-year-old woman was admitted to the Oita Medical University Hospital because of a nonproductive cough and exertional dyspnea. Interstitial changes had been seen on her chest radiograph 5 years previously, but no respiratory symptoms were identified at that time. On admission, chest radiography revealed linear and ground-glass opacities in the middle and lower lung fields. Computed tomography provided evidence of bronchiectasis and micro-honeycombing of the lungs, while lymphocyte and neutrophil counts in the bronchoalveolar lavage fluid were increased. Transbronchial lung biopsy demonstrated alveolitis and Masson's bodies. The patient was not a pigeon breeder, but she could have been exposed to pigeons at her workplace. Indeed, she had specific antibodies against pigeon serum and droppings, and her peripheral lymphocytes showed proliferation in response to pigeon serum. A positive provocation test involving inhalation of pigeon serum confirmed that she had chronic hypersensitivity pneumonitis caused by allergy to pigeons. This is a rare case of chronic hypersensitivity pneumonitis associated with wild pigeons, that progressed to pulmonary fibrosis. Antigen provocation testing proved to be of great value.

Granzyme activity in the inflamed lung is not controlled by endogenous serine proteinase inhibitors

Numerous lung diseases, such as hypersensitivity pneumonitis (HP), are characterized by the presence of activated alveolar CTL and NK cells. Since these cells produce granzymes, granzyme A and B levels in bronchoalveolar lavage (BAL) fluids from 14 normal subjects and 12 patients with HP were measured by ELISA. Median (range) BAL granzyme A and B levels were 4 (0-37) and 0 (0-6) pg/ml in normal subjects. BAL granzyme levels were significantly higher in HP patients, being at 74 (0-1,889) and 10 (0-78) pg/ml for granzymes A and B, respectively. In vitro, neither of the three main serine protease inhibitors of the lung, namely alpha1-antitrypsin, secretory leukocyte protease inhibitor, and elafin, showed any effect on granzyme A or B activity. In addition, granzyme A was shown to be fully active in BAL fluids. Hence, these data show that granzyme activity may be poorly controlled by protease inhibitors in inflamed tissues. Thus, granzymes could contribute to tissue remodeling and inflammation characterizing HP.

Small airway involvement in interstitial lung disease: radiologic evidence

High resolution computed tomography (HRCT) has considerably improved the ability to diagnose and characterize interstitial lung disease (ILD). This paper assesses the role of HRCT in evaluating small airway disease associated with ILD particularly sarcoidosis, hypersensitivity pneumonitis, and interstitial pulmonary fibrosis.

Relationship between inflammatory cells in bronchoalveolar lavage fluid and pathologic changes in the lung interstitium

Bronchoalveolar lavage (BAL) is recognized as an important research tool for various lung diseases, but it is still uncertain whether inflammatory cells in BAL fluid (BALF) accurately reflect pathologic changes in the lung interstitium. We used a morphometric method to quantify the density of inflammatory cells in the lung interstitium by utilizing a computer-aided graphic analyzer and compared those findings with BALF results. Two types of animal models were studied, i.e., endotoxemia (Escherichia coli endotoxin) and hypersensitivity pneumonitis (inhaled ovalbumin). Male Wistar rats were used; the right lungs were lavaged and the left lungs were prepared for morphometric study. In the endotoxemia model, the neutrophil fraction in BALF and the neutrophil density in the lung interstitium correlated significantly at 18 h (r = 0.81, p < 0.05) and 24 h (r = 0.81, p < 0.05) but not at any other time points after injection. In the hypersensitivity pneumonitis model, the neutrophil fraction in BALF and the neutrophil density in the lung interstitium correlated significantly (r = 0.80, p < 0.05) only at 3 h after inhalation. The lymphocyte fraction in BALF and the lymphocyte density in the lung interstitium were correlated positively at 3 h (r = 0.83, p < 0.05), 1 day (r = 0.82, p < 0.05), 2 days (r = 0.67, p = NS), and 4 days (r = 0.87, p < 0.05), but not at 6 days after inhalation. Our data suggest that neutrophil fraction in BALF does not reflect neutrophil populations in the lung interstitium except at the time of maximal neutrophil count in lung lavage. For lymphocytes in the hypersensitivity pneumonitis model, those in BALF and in the lung interstitium roughly correlate in the majority of measurements.

Mediators of hypersensitivity pneumonitis

Inhalation of Saccharopolyspora rectivirgula (S. rectivirgula) causes farmer's lung disease, a classic example of hypersensitivity pneumonitis (HP). HP is characterized by bronchoalveolar lavage fluid (BALF) neutrophilia (within the first 48 hours after inhalation), followed by BALF lymphocytosis. We utilized a well-described murine model of HP to determine the timing of the appearance of the C-C chemokines monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1alpha (MIP-1alpha); the inflammatory cytokines tumor necrosis factor (TNF), interleukin-1alpha (IL-1alpha), and interleukin-6 (IL-6); and the Th1 -differentiating cytokine interleukin-12 (IL-12) in BALF. After a single intratracheal administration of S. rectivirgula, there was remarkable BALF neutrophilia (peak 24 to 48 hours), followed by a BALF lymphocytosis (peak 48 to 72 hours) in both C57Bl/6 and BALB/c mice that was preceded by the appearance of MIP-1alpha in BALF (peak 4 to 6 hours) and MCP-1 (peak at 48 hours). In both strains of mice there was a striking increase of BALF IL-12 (peak 48 to 72 hours). There was also an increase in BALF IL-6, IL-1alpha, and TNF that was greater in the BALB/c mice than in the C57Bl/6 mice. S. rectivirgula induced the secretion of MIP-1alpha, MCP-1, IL-6, IL-1alpha, and IL-12 from the murine macrophage cell line J774A.1; MIP-1alpha, IL-6, IL-1alpha, IL-12, and TNF from C57Bl/6 alveolar macrophages; and IL-1alpha, IL-6, and TNF-but not IL-12-from BALB/c alveolar macrophages. We conclude that chemokines and cytokines induced by intratracheal administration of S. rectivirgula precede BALF neutrophilia and lymphocytosis and may cause differentiation of Th1 cells; we also conclude that pulmonary macrophages represent a potential source of these substances.

Increase of lung neutrophils in hypersensitivity pneumonitis is associated with lung fibrosis

Hypersensitivity pneumonitis (HP) is characterized by a T-cell-mediated alveolitis, and the putative role of other inflammatory cells in its pathogenesis remains unclear. In this study we determined whether increased quantities of neutrophils were present in HP lungs, and if they were positive for gelatinase B and collagenase-2. Fifteen nonsmoking patients with subacute/chronic active HP were included. Lung samples were analyzed using myeloperoxidase antibody, and neutrophil/total cell ratio was evaluated by digital processing. All HP tissue samples exhibited variable quantities of neutrophils located inside vessels, and in the interstitial and alveolar spaces. Lung neutrophil percentage ranged from 0.7% to 4.8% (2.1 +/- 1.4%). There was a positive correlation between the percentage of lung neutrophils and the percentage of lung fibrosis (r = 0.6, p < 0.02). Tissue neutrophils showed intense immunoreactive collagenase-2 and gelatinase B staining. Additionally, gelatinolytic activities corresponding to progelatinases A and B and their activated forms, were several-fold increased in the bronchoalveolar lavage fluid (BALF) from patients with HP as compared with control subjects. These findings suggest that in HP lungs there is a persistent traffic of neutrophils loaded with gelatinase B and collagenase-2 that may play a role in the lung damage and in the fibrotic response.

Inhibition of binding of E- and P-selectin to sialyl-Lewis X molecule suppresses the inflammatory response in hypersensitivity pneumonitis in mice

The carbohydrate structure of sialyl-Lewis X (SLe(x)) can function as a ligand for E- and P-selectin, which play important roles in mediating the initial interactions of leukocytes with the endothelium in inflammatory responses. In this study we evaluated the effects of inhibiting E- and P-selectin function with the SLe(x) molecule on the inflammatory response in an experimental murine model of hypersensitivity pneumonitis (HP). Antigen exposure induced marked interstitial and especially perivascular and peribronchiolar infiltration with lymphocytes and granuloma formation, in murine lung sensitized with Saccaropolyspora rectivirgula. These pathologic changes were significantly suppressed with SLe(x) ganglioside analogues through a reduction in the numbers of lymphocytes in bronchoalveolar lavage fluid, as evidenced by the lung index and histologic scores indicating the severity of the inflammatory response. Using specific antibodies, we also evaluated the immunohistochemical localization of SLe(x) in mononuclear cells in granulomas, and of E- and P-selectin in vascular endothelium. Our findings suggest that the molecular interaction between SLe(x), and E- and P-selectin mediates lymphocyte recruitment into the lung parenchyma, which is critical for the inflammatory response in experimental murine models of HP.

Muc-5/5ac mucin messenger RNA and protein expression is a marker of goblet cell metaplasia in murine airways

Airway inflammation, hyperreactivity, increased number of goblet cells, and mucus overproduction characterize asthma. Respiratory challenge with ovalbumin (OVA) of sensitized mice has been shown by several laboratories to cause pulmonary pathology similar to that observed in human allergic asthma. Recently, interleukin (IL)-13 has been shown to be a central mediator in this process. Because the airways of healthy mice have few, if any, mucus-producing cells, an increase in the number of these cells likely reflects induction of mucin-gene expression. The purpose of this study was to identify mucin genes induced as a result of airway goblet-cell metaplasia (GCM) in mice sensitized and challenged with OVA or in mice treated with IL-13 alone. BALB/c mice were sensitized by intraperitoneal injection (Days 0, 4, 7, 11, and 14) and intranasal instillation (Day 14) of 100 microg of OVA in saline, and then challenged by intranasal instillation (Days 25, 26, and 27) of the same. IL-13-treated mice received 5 microg of IL-13 by intranasal instillation on three consecutive days. Control mice were given saline alone. All mice were studied 24 h after the last challenge. Histologic analysis of the lungs revealed both a striking peribronchial and perivascular lymphocytic and eosinophilic inflammation and airway GCM in OVA-treated mice, and also airway GCM without inflammation in IL-13-treated mice. Northern blot analysis of lung RNA demonstrated (1) expression of Muc-5/5ac messenger RNA (mRNA) in OVA-treated and IL-13-treated mice, but not in control mice; (2) expression of Muc-1 mRNA at comparable levels in all mice regardless of treatment; and (3) no expression of Muc-2 or Muc-3 mRNA in control or treated mice. Western blot analysis demonstrated the expression of Muc-5/5ac protein (both apomucin and glycosylated mucin) in lung lysates of OVA-treated (but not control) mice, and also the expression of Muc-5/5ac mucins in the bronchoalveolar lavage fluid of OVA-treated and IL-13-treated mice. These findings demonstrate that airway GCM is associated with the induction of pulmonary expression of Muc-5/5ac mRNA and mucin in murine models of allergic asthma.

The invaluable pressure-volume curve

We present a case in which the pressure-volume (P-V) curve proved invaluable in the diagnostic workup of a patient. The patient was a 43-year-old man who presented with progressive dyspnea on exertion, restrictive spirometry, exercise desaturation, and an unremarkable CT scan. Because of the unexpected finding of an unremarkable CT scan, we wanted more data assuring the presence of an indication for lung biopsy. Detailed pulmonary function tests, including a P-V curve, were administered. The P-V curve was abnormal, thus prompting a biopsy, which revealed hypersensitivity pneumonitis. In this report, we discuss the use of P-V curves and the clinical presentation of hypersensitivity pneumonitis.

Manganese superoxide dismutase and catalase are coordinately expressed in the alveolar region in chronic interstitial pneumonias and granulomatous diseases of the lung

Free radicals have been suggested to play an important role in the pathogenesis of interstitial lung diseases, the most important of which are chronic interstitial pneumonias such as usual interstitial pneumonia (UIP) and desquamative interstitial pneumonia (DIP) and granulomatous lung diseases such as sarcoidosis. Because manganese superoxide dismutase (MnSOD) and catalase are two important intracellular antioxidant enzymes that probably play a central role in lung defense, the localization and intensity of these two enzymes were assessed by immunohistochemistry in biopsies of UIP (n = 9), DIP (n = 11), pulmonary sarcoidosis (n = 14), and extrinsic allergic alveolitis (n = 6). The mRNA of these enzymes in selected samples of bronchoalveolar lavage was assessed by Northern blotting. Catalase, but not MnSOD, was constitutively expressed, especially in type II pneumocytes of the healthy lung of nonsmoking individuals. In contrast, manganese SOD immunoreactivity was markedly upregulated in all of the interstitial lung diseases investigated, whereas no increased expression of catalase could be detected in any case. Both enzymes were expressed, especially in type II pneumocytes and alveolar macrophages of DIP and UIP, in the well-preserved areas of the lung, in the acute fibromyxoid lesions of UIP, and in the granulomas of sarcoidosis and extrinsic allergic alveolitis. The simultaneous expression of MnSOD and catalase in the alveolar region suggests their protective role against the progression of lung disease.