Organic dust-induced lung injury and repair: Bi-directional regulation by TNFα and IL-10.

Exposure to organic dust increases chronic airway inflammatory disorders. Effective treatment strategies are lacking. It has been reported that hog barn dust extracts (HDE) induce TNFα through protein kinase C (PKC) activation and that lung inflammation is enhanced in scavenger receptor A (SRA/CD204) knockout (KO) mice following HDE. Because interleukin (IL)-10 production can limit excessive inflammation, it was hypothesized here that HDE-induced IL-10 would require CD204 to effect inflammatory responses. C57BL/6 wild-type (WT), SRA KO, and IL-10 KO mice were intranasally challenged daily for 8 days with HDE and subsequently rested for 3 days with/without recombinant IL-10 (rIL-10) treatment. Primary peritoneal macrophages (PM) and murine alveolar macrophages (MH-S cells) were treated in vitro with HDE, SRA ligand (fucoidan), rIL-10, and/or PKC isoform inhibitors. HDE induced in vivo lung IL-10 in WT, but not SRA KO mice, and similar trends were demonstrated in isolated PM from same treated mice. Lung lymphocyte aggregates and neutrophils were elevated in in vivo HDE-treated SRA and IL-10 KO mice after a 3-d recovery, and treatment during recovery with rIL-10 abrogated these responses. In vitro rIL-10 treatment reduced HDE-stimulated TNFα release in MH-S and WT PM. In SRA KO macrophages, there was reduced IL-10 and PKC zeta (ζ) activity and increased TNFα following in vitro HDE stimulation. Similarly, blocking SRA (24 hr fucoidan pre-treatment) resulted in enhanced HDE-stimulated macrophage TNFα and decreased IL-10 and PKCζ activation. PKCζ inhibitors blocked HDE-stimulated IL-10, but not TNFα. Collectively, HDE stimulates IL-10 by an SRA- and PKCζ-dependent mechanism to regulate TNFα. Enhancing resolution of dust-mediated lung inflammation through targeting IL-10 and/or SRA may represent new approaches to therapeutic interventions.

Immunoreactive proteins of Saccharopolyspora rectivirgula for farmer's lung serodiagnosis.

PURPOSE: Saccharopolyspora rectivirgula is the principal cause of farmer's lung disease (FLD). Serodiagnosis is based on immunoprecipitation techniques or enzyme immunoassays with homemade crude antigens and is not standardized. We aimed to produce specific recombinant antigens for the development of a standardized ELISA. EXPERIMENTAL DESIGN: We recruited 41 patients and 43 healthy exposed controls from five university hospital pneumology departments in France and Switzerland. S. rectivirgula proteins were extracted, separated by 2D electrophoresis, and subjected to Western blotting, with sera from FLD patients or controls. FLD-specific proteins were identified by MS and were produced as recombinant antigens. The diagnostic performance of ELISA tests using the recombinant antigens was assessed with all the sera from FLD patients and controls. RESULTS: We identified 25 FLD-specific proteins, some of which play important roles in transport, nutrition, or virulence. We produced 17 of these proteins as recombinant antigens and assessed their suitability for inclusion in the ELISA test. A combination of three of these proteins (SR1FA, SR17, and SR22) proved remarkably effective at discriminating between patients and controls, with a sensitivity of 83% and a specificity of 77%. CONCLUSIONS AND CLINICAL RELEVANCE: The recombinant antigens produced in this study constitute a major step toward the improvement of diagnostic performance and the standardization of FLD serodiagnosis.

[Farmer's lung antigens in Germany]. / Farmerlungen-Antigene in Deutschland.

Recent studies suggest that besides the long-known farmer's lung antigen sources Saccharopolyspora rectivirgula (Micropolyspora faeni), Thermoactinomyces vulgaris, and Aspergillus fumigatus, additionally the mold Absidia (Lichtheimia) corymbifera as well as the bacteria Erwinia herbicola (Pantoea agglomerans) and Streptomyces albus may cause farmer's lung in Germany. In this study the sera of 64 farmers with a suspicion of farmer's lung were examined for the following further antigens: Wallemia sebi, Cladosporium herbarum, Aspergillus versicolor, and Eurotium amstelodami. Our results indicate that these molds are not frequent causes of farmer's lung in Germany.

Farmer's lung in a case after bullectomy.

We present a case of farmer's lung (FL) with the primary presenting feature of a large bulla in the lung. A 70-year-old nonsmoking woman with dyspnea on exercise was referred for surgical resection of a large bulla in the lung. The postoperative evaluation of the lung tissue revealed a follicular lymphocytic alveolitis and loosely formed granulomas suspicious for hypersensitivity pneumonitis (HP). The patient had worked in farming since her youth. Dyspnea on exercise was the only symptom, but it was related to the large bulla. No other radiologic features of HP were shown in a high-resolution CT of the lung. Specific IgG antibodies against typical antigens of FL were detected, bronchoalveolar lavage demonstrated no lymphocytic alveolitis but an inhalative challenge with own hay was positive. A diagnosis of chronic FL was made. Despite lung emphysema being a possible reaction in FL, giant bullae as primary and single manifestation of this disease have not been reported before.

Daily exposure to dust alters innate immunity.

Pig farmers are exposed to organic material in pig barns on a daily basis and have signs of an ongoing chronic airway inflammation and increased prevalence of chronic inflammatory airway diseases, predominantly chronic bronchitis. Interestingly, the inflammatory response to acute exposure to organic dust is attenuated in farmers. The aim of the study was to closer characterize innate immunity features in blood and airways in farmers and in naïve, non-exposed, controls. The expression of pattern recognition receptors (TLR2, TLR4 and CD14) whose ligands are abundant in pig barn dust and adhesion proteins (CD11b, CD62L and CD162L) on blood and sputum neutrophils in pig farmers and soluble TLR2 and CD14 (sTLR2 and sCD14) in blood and sputum were assessed in pig farmers and previously unexposed controls. The release of pro-inflammatory cytokines from blood cells stimulated with LPS ex vivo was measured in the absence and presence of anti-ST2. We also examined, in a separate study population, serum levels of soluble ST2 (sST2), before and after exposure in a pig barn and a bronchial LPS challenge. Farmers had signs of ongoing chronic inflammation with increased number of blood monocytes, and decreased expression of CD62L and CD162 on blood neutrophils. Farmers also had lower levels of sTLR2 and sCD14 in sputum and reduced expression of CD14 on sputum neutrophils than controls. Exposure to organic dust and LPS induced increase of serum sST2 in controls but not in farmers. In conclusion, farmers have signs of local and systemic inflammation associated with altered innate immunity characteristics.

Bronchoalveolar lavage in hypersensitivity pneumonitis: a series of 139 patients.

Hypersensitivity pneumonitis (HP) is characterized by a lymphocytic alveolitis, classically delineated by an increase of CD8+ lymphocytes, with an inversion of the CD4+/CD8+ ratio. The aim of this study is both to describe the yield and cell bronchoalveolar lavage (BAL) profile and to revisit the assumption of low BAL CD4/CD8 ratio in the diagnosis of HP. A multicentric study was conducted on 139 patients who fulfilled the standardized diagnostic criteria of HP, mainly affected by farmer's lung. Mean total cell count in BAL fluid was 594 ± 401.10(3) cells /ml. Prominent absolute lymphocytic alveolitis, moderate neutrophilia, and mild eosinophilia and mastocytosis were found. Mean CD4/CD8 ratio was 3.8 ± 6.1 (median 2.1). Thirty four percent of the patients showed lymphocytic CD8 alveolitis (ratio < 1). The CD4/CD8 ratio was not different between forms, etiologies of HP, and time elapsed since last antigen exposure, but was higher in women (p=0.02). BAL in HP shows high total cell and lymphocyte counts, moderate neutrophilia, and mild eosinophilia and mastocytosis. An absence of low CD4/CD8 ratio should not at all exclude diagnosis.

Farmer's lung-induced hypersensitivity pneumonitis complicated by shock.

Hypersensitivity pneumonitis is an immunologic reaction to an inhaled antigen, with a wide spectrum of clinical presentations. The most common manifestations are fever, cough, and dyspnea. We describe a case of hypersensitivity pneumonitis with marked alveolar lymphocytosis; the patient presented with respiratory failure and shock requiring mechanical ventilation and vasopressive agents. We hypothesized that immune mediators implicated in the pathogenesis of hypersensitivity pneumonitis were responsible for the transient shock observed in this patient.

New evidence of the involvement of Lichtheimia corymbifera in farmer's lung disease.

Farmer's lung disease (FLD) is a form of hypersensitivity pneumonitis resulting from recurrent exposure to moldy plant materials. We investigated and compared the initial response of respiratory epithelium after exposure to extracts of Sacharopolyspora rectivirgula, Lichtheimia corymbifera (formerly Absidia corymbifera), Eurotium amstelodami and Wallemia sebi. The two criteria for selection of these species were their high prevalence in the hay handled by FLD patients and the presence of high levels of specific precipitins to these molds in FLD patients’ sera. Hydrosoluble extracts were prepared from spores and hyphae grown in culture under optimal conditions for each of the four species. Confluent A549 cells were inoculated with one of the four calibrated soluble extracts. Two mediators, one inflammatory (Interleukin (IL)-8) and one allergic (IL-13), were quantified using real-time PCR and ELISA assay, after four exposure periods (30 min, 2 h, 4 h and 8 h). S. rectivirgula and L. corymbifera extracts were the only ones which induced a marked upregulation of IL-8, as shown by both real-time PCR and ELISA assay 8 h after the initial contact. This study adds to the growing body of evidence that L. corymbifera should be recognized as an etiologic agent of FLD along with S. rectivirgula.

Protein kinase D1 is essential for the proinflammatory response induced by hypersensitivity pneumonitis-causing thermophilic actinomycetes Saccharopolyspora rectivirgula.

Hypersensitivity pneumonitis is an interstitial lung disease that results from repeated pulmonary exposure to various organic Ags, including Saccharopolyspora rectivirgula, the causative agent of farmer's lung disease. Although the contributions of proinflammatory mediators to the disease pathogenesis are relatively well documented, the mechanism(s) involved in the initiation of proinflammatory responses against the causative microorganisms and the contribution of signaling molecules involved in the host immune defense have not been fully elucidated. In the current study, we found that S. rectivirgula induces the activation of protein kinase D (PKD)1 in lung cells in vitro and in vivo. Activation of PKD1 by S. rectivirgula was dependent on MyD88. Inhibition of PKD by pharmacological PKD inhibitor Gö6976 and silencing of PKD1 expression by small interfering RNA revealed that PKD1 is indispensable for S. rectivirgula-mediated activation of MAPKs and NF-kappaB and the expression of various proinflammatory cytokines and chemokines. In addition, compared with controls, mice pretreated with Gö6976 showed significantly suppressed alveolitis and neutrophil influx in bronchial alveolar lavage fluid and interstitial lung tissue, as well as substantially decreased myeloperoxidase activity in the lung after pulmonary exposure to S. rectivirgula. These results demonstrate that PKD1 is essential for S. rectivirgula-mediated proinflammatory immune responses and neutrophil influx in the lung. Our findings also imply the possibility that PKD1 is one of the critical factors that play a regulatory role in the development of hypersensitivity pneumonitis caused by microbial Ags and that inhibition of PKD1 activation could be an effective way to control microbial Ag-induced hypersensitivity pneumonitis.

[Three cases of hypersensitivity pneumonitis in citrus farmers].

We report 3 cases of occupational hypersensitivity pneumonitis in citrus farmers. They were admitted to our hospital with abnormal chest shadows with coughs, fevers and breathlessness between January and February, but their symptoms disappeared with isolation from their workplace. The diagnoses were comprehensively confirmed by their occupational histories, radiological findings, and the positive findings of environmental provocation tests. Although we cannot clearly determine the pathogenic antigen of this hypersensitivity pneumonitis, Aspergillus and Penicillium might be the causative agents, because they were detected in the patients' workplaces and in double immunodiffusion tests. In Ouchterlony's immunodiffusion test, these antigens were positive in some patients.

Respiratory health effects and immunological response to Thermoactinomyces among sugar cane workers in Nicaragua.

Specific sensitization and respiratory effects associated with the inhalation of sugar cane dust were evaluated in a group of 51 Nicaraguan workers exposed to bagasse. A questionnaire interview, lung function test, serum precipitin tests for Thermoactinomyces sacchari and T. vulgaris, and immunoglobulin E tests for specific environmental allergens were performed for each worker. Twenty-one workers reported at least one respiratory symptom and 16 reported possible symptoms of bagassosis. Six workers demonstrated acute symptoms, 1 had chronic symptoms, and 9 had the reacutized form of the disease. A higher proportion of precipitin response to T. sacchari and T. vulgaris was found in workers reporting symptoms suggestive of acute bagassosis. A possible restrictive ventilatory pattern was observed in 8 subjects and a mild airway obstruction in 1 subject. Priority must be given to a surveillance and exposure prevention program for workers employed in sugar cane production and processing.

Th17-polarized immune response in a murine model of hypersensitivity pneumonitis and lung fibrosis.

Hypersensitivity pneumonitis is an environmental lung disease characterized by a diffuse mononuclear cell infiltrate in the lung that can progress to pulmonary fibrosis with chronic exposure to an inhaled Ag. Using a well-established murine model of hypersensitivity pneumonitis, we repeatedly exposed C57BL/6 mice to Saccharopolyspora rectivirgula to investigate whether T cells are required for lung fibrosis. In the absence of alphabeta T cells, TCRbeta(-/-) mice exposed to S. rectivirgula for 4 wk had markedly decreased mononuclear infiltrates and collagen deposition in the lung compared with wild-type C57BL/6 mice. In contrast to CD8(+) T cells, adoptive transfer of CD4(+) T cells reconstituted the S. rectivirgula-induced inflammatory and fibrotic response, suggesting that the CD4(+) T cell represents the critical alphabeta T cell subset. Cytokine analysis of lung homogenates at various time points after S. rectivirgula exposure failed to identify a predominant Th1 or Th2 phenotype. Conversely, IL-17 was found in the lung at increasing concentrations with continued exposure to S. rectivirgula. Intracellular cytokine staining revealed that 14% of CD4(+) T cells from the lung of mice treated with S. rectivirgula expressed IL-17A. In the absence of IL-17 receptor signaling, Il17ra(-/-) mice had significantly decreased lung inflammation and fibrosis compared with wild-type C57BL/6 mice. These data are the first to demonstrate an important role for Th17-polarized CD4(+) T lymphocytes in the immune response directed against S. rectivirgula in this murine model of hypersensitivity pneumonitis and pulmonary fibrosis.

[Farmer's lung disease caused by straw or hay? Case report]. / Hálmsótt eda heysótt?

A young woman was admitted to Akranes Regional Hospital because of dyspnea, fatigue and fever. She was found to have bilateral pneumonia but etiology was not found. She was treated with antibiotics with good resolution and was discharged after eight days from the hospital. Four weeks later she noticed rapidly progressive dyspnea and was found to be hypoxemic, and to have restrictive spirometry and diffuse interstitial changes on chest radiography. Computerized tomography of the lungs showed diffuse ground glass changes. Transbronchial biopsies from the lungs showed numerous small granulomas. She was treated with prednisolone for a short time with excellent recovery. She stall-fed horses and underneath them was straw containing organic dust. This is important to keep in mind as a differential diagnosis to farmers lung disease that is caused by hay.

Significance of precipitins and asymptomatic lymphocytic alveolitis: a 20-yr follow-up.

What is the significance of serum precipitins and lymphocytic alveolitis in a healthy subject exposed to antigens responsible for hypersensitivity pneumonitis (HP)? This study was done to evaluate the 20-yr outcome of asymptomatic dairy farmers with or without precipitins or lymphocytic alveolitis in their bronchoalveolar lavage (BAL). Twenty-seven of the initial 43 farmers were restudied. Of the missing 16, 11 refused the follow-up, three had died and two could not be located. The restudied farmers had a clinical evaluation, lung function tests and a high resolution computed tomography (HRCT). Only one subject, an asthmatic, had dyspnoea, none described present or past symptoms suggestive of HP. Of those who were no longer on the farm, none had quit because of respiratory problems. Lung function changes were as expected with aging. The only difference was that farmers with positive precipitins had a statistically significant greater decrease in their forced expiratory volume in one second than the sero-negative farmers. Four HRCTs showed signs of minimal parenchymal abnormalities; these were not more prevalent for subjects with or without precipitins or BAL lymphocytosis. Serum precipitins and asymptomatic lymphocytic alveolitis in an asymptomatic, exposed dairy farmer have no clinically meaningful long-term consequences.

[Dermatologic occupationally relevant type I allergies]. / Berufsdermatologisch relevante Typ-I-Allergien.

In Germany the most frequent initial report of occupational disease is due to occupational skin diseases ("Berufskrankheitenanzeige nach Nr. 5101 der Berufskrankheitenverordnung") defined as "severe or recurrent skin diseases that force the discontinuation of any activity that causes or that could be causing the development, the worsening, or the recurrence of the skin disease". The majority of these occupational skin diseases consists of irritant and allergic contact dermatitis. In contrast, work place- related Type I allergy (contact urticaria syndrome) is less frequent, but carries the risk of systemic reactions. The clinical manifestations and pattern of exposure to Type I allergens in the work place are described.

[Pulmonary fibrosis in young patients with hypersensitivity pneumonitis]. / Zwlóknienie pluc u mlodych chorych na alergiczne zapalenie pecherzyków plucnych.

UNLABELLED: Hypersensitivity pneumonitis (HP) is more common in middle-aged individuals but has been also diagnosed in patients of all ages including infants and children. Host risk factors are poorly characterized. The aim of this paper is presentation of 6 young patients in whom HP was diagnosed at the stage of lung fibrosis. There were 5 females at the age of 16-35 years and 1 male at the age of 28 years. All of them were exposed to organic dust for many years. Three of them were asthenic with scoliosis, 5 had clubbing. All patients were released from sport exercises in school due to fatigue but the diagnostic procedures were started at that time only in 2 patients. One woman had been ill from early childhood (recurrent pneumonia was recognised). In the another girl (16 years old) the spontaneous pneumothorax was the cause of the first chest X-ray examination. In the next woman (21 years old) marked dyspnea was connected with pregnancy and massive fibrotic lesions were recognised after delivery of her child. The only man was diagnosed before change of his job; he had no complaints. Two oldest women (34 and 35 years old) were diagnosed in childhood but avoidance of antigen exposure and corticotherapy were not effective. In all patients precipitins against farmer's lung and pigeon fancier's lung antigens were found. In all patients chest X-ray showed features of advanced lung fibrosis. All patients were treated with steroids without improvement. Two patients died during corticotherapy. CONCLUSIONS: 1) HP could be taken into consideration during differential diagnosis of interstitial lung diseases, 2) Cough and dyspnea on exertion could be the first symptoms of chronic HP in children also.

Experimental hypersensitivity pneumonitis: role of MCP-1.

Inhalation of Saccharopolyspora rectivirgula causes "farmer's lung" disease, a classic example of hypersensitivity pneumonitis (HP). Monocyte chemoattractant protein-1 (MCP-1) is increased in the bronchoalveolar lavage fluid of mice challenged with S rectivirgula, and S rectivirgula induces MCP-1 secretion by alveolar macrophages. We tested the hypothesis that MCP-1 and its receptor CC chemokine receptor-2 (CCR2) are essential to the development of experimental HP by treating mice with MCP-1 antibody and using CCR2(-/-) mice. Administration of anti-MCP-1 did not change the response to intratracheally administered S rectivirgula. CCR2(-/-) animals responded in a fashion similar to that of wild-type animals to intratracheally administered.S rectivirgula. To determine the influence of the MCP-1-CCR2 interaction in vitro, we transferred S rectivirgula-cultured spleen cells from S rectivirgula-sensitized mice, to naïve recipients. Later, challenge of the recipients with intratracheal S rectivirgula and examination of both lung histology and bronchoalveolar lavage fluid characteristics were used to determine whether adoptive transfer had occurred. We found that cultured cells from CCR2(-/-) animals were fully capable of adoptive transfer. We conclude that interaction of MCP-1 with CCR2 is not necessary for the development of pulmonary inflammation in response to intratracheally administered S rectivirgula or cells able to adoptively transfer experimental HP.

Role of molds in farmer's lung disease in Eastern France.

Farmer's lung disease (FLD) is common in the east of France. In the absence of the primary recognized FLD agent, Saccharopolyspora rectivirgula, its etiology remains unknown. A prospective case-control study was performed to find the etiology of FLD in this area. Eleven patients were matched with 11 healthy control farmers. Twenty-two urban subjects constituted the nonexposed control group. Microorganisms from cowshed air and fodder were identified and counted. The antigens of the microorganisms most frequently isolated at the 22 farms were used for serological tests. Farms of patients with FLD contained more Absidia corymbifera than those of healthy farmers (p < 0.05 in air, p < 0.01 in fodder). Electrosyneresis, performed with A. corymbifera somatic antigen, differentiated 9 of 11 patients with FLD from control subjects (p < 0.01). Other significant results were obtained with Eurotium amstelodami (p < 0.01) and Wallemia sebi (p < 0.05). In contrast, no significant results were obtained with the other seven antigens tested, including S. rectivirgula. Absidia corymbifera and, to a lesser degree, W. sebi or E. amstelodami are likely to be the main causes of FLD in this area. Modifications in working conditions over time could explain the emergence of these new contributing etiologies.