Diagnostic value of serum precipitins to mould antigens in active hypersensitivity pneumonitis

Serum precipitins have a controversial diagnostic value in hypersensitivity pneumonitis (HP). The present authors' objective was to assess their diagnostic value by developing scores from a panel of specific antigens tested by two techniques (electrosyneresis and double diffusion) to discriminate active HP from other interstitial lung diseases. Consecutive patients presenting with a condition for which HP was considered in the differential diagnosis were included in the study. All patients underwent the same standardised diagnostic procedure, including precipitin tests performed in routine conditions. Clinical manifestations, bronchoalveolar lavage and high-resolution computed tomography defined the presence or absence of HP. Receiver-operating characteristic curves and logistic regression were used to develop the serological scores. A total of 122 patients (including 31 cases of HP) were included in the study. Five antigens from the panel were selected for the serological scores (Absidia corymbifera, Eurotium amstelodami, Wallemia sebi, Saccharopolyspora rectivirgula and mesophilic Streptomyces sp.). Electrosyneresis was more discriminative than the double-diffusion technique. Predictive negative values varied 81-88% and predictive positive values varied 71-75% for prevalence of HP 20-35%. In conclusion, serological scores using a panel of relevant antigens may guide both biological and clinical practice in areas of high prevalence of hypersensitivity pneumonitis.

Circulating intercellular adhesion molecule-1 (ICAM-1) antigen in sera of patients with idiopathic pulmonary fibrosis

Intercellular adhesion molecule-1 (ICAM-1), a member of immunoglobulin supergene family with a five-domain structure, is known to play an important role in inflammatory diseases. An ELISA was developed using two MoAbs against human ICAM-1 in order to detect the soluble shedding ICAM-1 antigen in sera. We measured levels of circulating ICAM-1 antigen in sera of patients with idiopathic pulmonary fibrosis (IPF), pulmonary sarcoidosis, hypersensitive pneumonitis, bacterial and mycoplasmal pneumonia, and inflammatory diseases of other organs. The results clearly demonstrated that IPF had significantly high levels of circulating ICAM-1 in sera as compared with other disorders or normal controls. Moreover, immunohistochemical analysis with MoAb against human ICAM-1 disclosed that in IPF, the expression of ICAM-1 was intensively enhanced on alveolar epithelial cells. These results suggest that ICAM-1 may contribute to the pathogenesis of IPF.

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.

Summer-type hypersensitivity pneumonitis. A unique disease in Japan

A unique form of hypersensitivity pneumonitis in which clinical symptoms appear in the summer and subside spontaneously in the mid-autumn was found in Japan. This disease was named summer-type hypersensitivity pneumonitis and was found the most prevalent form in Japan. This disease has the following characteristic features: 1) initiation in the summer; 2) repeated episodes during subsequent seasons for many years; 3) familial occurrence; 4) no occupational relationship; 5) positive returning-home provocation test; 6) cough, dyspnea and remittent fever as a clinical triad; 7) diffuse nodular shadows on chest x-ray film; 8) leukocytosis with neutrophilia; 9) moderately decreased % VC and markedly decreased Dco and PaO2; 10) skin reactivity to PPD is negative while symptomatic; 11) pulmonary lesions of biopsied specimens show epithelioid cell granulomas without central necrosis (63.3 percent), plus alveolitis and/or pneumonitis; 12) isolation of patients from their home environment diminishes symptoms; 13) corticosteroid is effective; 14) seasonal atmospheric microbiological pollution is speculated upon, but the offending antigen is not defined yet.

Production of Soluble Tumor Necrosis Factor Receptors and Tumor Necrosis Factor-α by Alveolar Macrophages in Sarcoidosis and Extrinsic Allergic Alveolitis

BACKGROUND

Alveolar macrophage (AM)-derived tumor necrosis factor (TNF)-alpha plays a pivotal role in the pathogenesis of sarcoidosis and extrinsic allergic alveolitis (EAA). The effects of TNF-alpha are mediated by membrane TNF receptor (mTNFR)-1 and mTNFR-2, and can be blocked by soluble TNF receptor (sTNFR)-1 and sTNFR-2.

METHODS

We measured the production of the two sTNFRs and TNF-alpha in AM culture supernatants from 10 patients with active sarcoidosis, 12 patients with EAA, and 9 control subjects using an enzyme-linked immunosorbent assay method.

RESULTS

Compared with control subjects, the spontaneous and lipopolysaccharide (LPS)-stimulated production of sTNFR-1, sTNFR-2, and TNF-alpha was significantly increased in patients with sarcoidosis and EAA. The concentrations of both sTNFRs, but especially of sTNFR-2, were closely related to those of TNF-alpha. The LPS-induced increase was 1.5-fold for sTNFR-1, at least fourfold for sTNFR-2, and at least 25-fold for TNF-alpha in all study populations.

CONCLUSION

These results indicate that AMs can release the two sTNFRs in relation to TNF-alpha. sTNFR-2 may be more liable to shedding than sTNFR-1. Both sTNFR-1 and sTNFR-2 may be involved in the pathogenesis of sarcoidosis and EAA, possibly as counterregulators of TNF-alpha.

Selection of T lymphocytes bearing limited TCR-Vbeta regions in the lung of hypersensitivity pneumonitis and sarcoidosis

Hypersensitivity pneumonitis (HP) and sarcoidosis are interstitial lung disorders (ILD) characterized by a lymphocytic alveolitis that, in the active phase of the disease, is sustained by different T-cell subsets, i.e., CD8+ cells in HP and CD4+ lymphocytes in sarcoid patients. To address the question of whether a bias in T-cell selection occurs in the lung of patients with HP and sarcoidosis, we analyzed the T-cell receptor beta chain variable region (TCR-Vbeta) repertoire by flow cytometry and polymerase chain reaction (PCR) analyses in blood and lung lymphocytes of 14 HP and 25 sarcoid patients. To verify whether these cells can be activated in vitro through the TCR, blood and lung lymphocytes were also assessed for their responsiveness to different superantigenic stimuli represented by staphylococcal enterotoxins, including SEA, SEB, SEC1, SEC2, SED, and SEE. Flow cytometry and PCR analyses demonstrated an overexpression of cells bearing Vbeta2, Vbeta3, Vbeta5, Vbeta6, and Vbeta8 gene segments in the lung of HP patients as compared with the peripheral blood. In sarcoid patients cells bearing Vbeta2, Vbeta5, and Vbeta6 gene segments in the lung of HP patients as compared with the peripheral blood. In sarcoid patients cells bearing Vbeta2, Vbeta5, and Vbeta6 gene segments were overrepresented in the lung rather than in the blood. Both in HP and sarcoid patients almost all T cells bearing the dominant Vbeta segment belonged to the T-cell subset that sustains the alveolitis, i.e., CD8 in HP patients and CD4 in sarcoid subjects. Follow-up studies demonstrated that the recovery of the alveolitis was characterized by the disappearance of cells bearing a limited T-cell repertoire. Interestingly, T-lymphocyte response to different superantigens demonstrated that the proliferation elicited by different staphylococcal toxins was more pronounced in the lung than in the blood. Taken together, our findings indicate a compartmentalization of cells bearing discrete Vbeta gene products in the pulmonary microenvironment and suggest that the expansion of specific Vbeta region subsets occurring in the lung might result from triggering by a specific antigen. In fact, the removal from exposure in HP patients or specific treatment in sarcoidosis resulted in the decrease of the overrepresented cell population accounting for the lymphocytic alveolitis.

Mushroom worker's lung caused by spores of Hypsizigus marmoreus (Bunashimeji): elevated serum surfactant protein D levels

This is a report on two patients with occupational hypersensitivity pneumonitis (HP) caused by spores of Hypsizigus marmoreus (Bunashimeji) and serial follow-up measurements of serum surfactant protein D (SP-D) levels. The diagnosis of HP was confirmed immunologically by the detection of serum precipitins to spores of Bunashimeji, but not to other antigens, and by the positive results of in vitro lymphocyte proliferative response for Bunashimeji antigens using BAL fluid lymphocytes. This is the first case report of HP caused by Bunashimeji. Serum SP-D levels for the two patients (493 and 226 ng/mL; cut off level, 110 ng/mL) were elevated at diagnosis and decreased after separation from antigens following corticosteroid therapy. However, in one patient who returned to the same job, the symptoms appeared again and SP-D level also increased.

Sequential bronchoalveolar lavage in experimental extrinsic allergic alveolitis. The influence of cigarette smoking

We studied the alterations induced by acute experimental extrinsic allergic alveolitis (EAA) on bronchoalveolar cell population in smoking and nonsmoking guinea pigs. Sixty-two animals divided into 3 groups were studied: Group 1 (17 animals), controls; Group 2 (21 animals), extrinsic alveolitis; Group 3 (24 animals), cigarette smoking and alveolitis. Bronchoalveolar lavages (BAL) were performed on Days 1, 19, and 44 for all animals. Group 3 animals had a fourth lavage before starting cigarette smoking, that is, 28 days before the beginning of the antigen injections. The other lavages were as for the other groups. BAL results on Day 1 were similar for each group. Cigarette smoking per se did not modify BAL in Group 3. EAA induction resulted in a large increase in all BAL cells, especially neutrophils of recovered fluid, which increased from 38 x 10(3) to 1,474 x 10(3) ml-1 (p less than 0.01) in Group 2 and from 58 x 10(3) to 740 x 10(3) in Group 3 (p less than 0.01). After maintenance, BAL neutrophils.ml-1 decreased to 444 x 10(3) in Group 2 (p less than 0.01), but stayed the same in Group 3: 973 x 10(3). After EAA induction, BAL neutrophils.ml-1 were higher in Group 2 than in Group 3 (p = 0.039); however, Group 2 had less neutrophils.ml-1 than Group 3 (p = 0.035) after EAA maintenance. We conclude that EAA results in a neutrophilic alveolitis and which can be evaluated by sequential BAL, and that cigarette smoking decreases the initial neutrophilic response and retards the eventual recovery during maintenance injections.

A clinical study of minocycline-induced pneumonitis

We studied the clinical features of minocycline-induced pneumonitis in seven patients. Acute symptoms included fever, dry cough and dyspnea, indicating acute respiratory failure. Diffuse ground glass shadows with Kerley's B lines, bronchial wall thickening, swelling of vascular bundles and pleural effusion were visible on radiography. Bronchoalveolar lavage or transbronchial lung biopsy confirmed pulmonary eosinophilia. Cessation of minocycline led to rapid remission with no treatment or only short-term steroid therapy. The lymphocyte stimulation test for minocycline with peripheral blood lymphocytes was not found to be useful for diagnosis.

Ia-like antigens on T-cells and their subpopulations in pulmonary sarcoidosis and in hypersensitivity pneumonitis. Analysis of bronchoalveolar and blood lymphocytes

We investigated the expression of Ia antigens on T-cells from lung and blood, as a sign of T-cell activation, in 17 patients with active pulmonary sarcoidosis, 12 patients with inactive sarcoidosis, 9 patients with hypersensitivity pneumonitis, and 10 normal control subjects. Lymphocyte subsets were identified by mouse monoclonal antibodies using a peroxidase-antiperoxidase method. Patients with active sarcoidosis and patients with hypersensitivity pneumonitis had a significant increase in Ia+ T-cells in bronchoalveolar lavage fluid compared with that in patients with inactive sarcoidosis and that in control subjects (p less than 0.01). Blood T-cells from the same patients did not show this sign of activation. The highest numbers of Ia+ T-cells were recovered from the lungs of patients with hypersensitivity pneumonitis, indicating the high state of activation of immunoregulatory T-cells in this disease. Additional analysis revealed that in sarcoidosis, Ia+ lung T-cells were exclusively of the OKT4+ helper phenotype, whereas in hypersensitivity pneumonitis, OKT4+ helper as well as OKT8+ suppressor lung cells expressed in part Ia antigens. These observations suggest that different T-cell subpopulations are activated in sarcoidosis and in hypersensitivity pneumonitis.

Elevated Serum Amyloid a Levels Are not Specific for Sarcoidosis but Associate with a Fibrotic Pulmonary Phenotype

Elevated Serum Amyloid A (SAA) levels have been found in several inflammatory diseases, including sarcoidosis. SAA is suggested to be involved in sarcoidosis pathogenesis by involvement in granuloma formation and maintenance. We hypothesized that SAA serum levels would be higher in sarcoidosis compared to other non-infectious granulomatous and non-granulomatous diseases. SAA levels were measured in serum from sarcoidosis, Hypersensitivity pneumonitis (HP), and (eosinophilic) granulomatosis with polyangiitis ((E)GPA) patients. Idiopathic pulmonary fibrosis (IPF) patients were included as non-granulomatous disease group. SAA levels of patients with sarcoidosis (31.0 µg/mL), HP (23.4 µg/mL), (E)GPA (36.9 µg/mL), and IPF (22.1 µg/mL) were all higher than SAA levels of healthy controls (10.1 µg/mL). SAA levels did not differ between the diagnostic groups. When SAA serum levels were analyzed in sarcoidosis subgroups, fibrotic sarcoidosis patients showed higher SAA levels than sarcoidosis patients without fibrosis (47.8 µg/mL vs. 29.4 µg/mL, p = 0.005). To conclude, the observation that fibrotic sarcoidosis patients have higher SAA levels, together with our finding that SAA levels were also increased in IPF patients, suggests that SAA may next to granulomatous processes also reflect the process of fibrogenesis. Further studies should clarify the exact role of SAA in fibrosis and the underlying mechanisms involved.

Humidifier lung: possible contribution of endotoxin-induced lung injury

A 56-year-old man was admitted with cough, fever, myalgia, and arthralgia. Chest computed tomography demonstrated bilateral diffuse ground-glass opacities predominantly in the upper lungs. Subpleural non-segmental consolidation was observed in the late phase. Hypersensitivity pneumonitis was suspected, and an environmental provocation test with the incidental use of a home ultrasonic humidifier was positive. Unlike typical hypersensitivity pneumonitis, serum KL-6 levels were normal. Although several microorganisms were isolated from the humidifier water, there was no evidence for immune sensitization. We detected high amounts of endotoxin in the humidifier water, which may have contributed to the lung injury of this patient.

Antigen characterization of major cork moulds in Suberosis (cork worker's pneumonitis) by immunoblotting

BACKGROUND

We characterized by immunoblotting the antigenicity of the most frequent fungi colonizing cork during its industrial processing, Penicillium glabrum and Chrysonilia sitophila. Penicillium glabrum is the main causative agent of Suberosis, a hypersensitivity pneumonitis of cork workers. Chrysonilia sitophila induces both IgE sensitization and occupational asthma in the wood processing industry.

METHODS

Serum-specific IgG, IgG4 and IgE to P. glabrum and C. sitophila from nine cork workers with hypersensitivity pneumonitis (HP) and seven with asthma (four with occupational asthma) were analysed by immunoblotting.

RESULTS

Both HP and asthmatic patients' sera showed immunoreactivity to several proteins resolved in the specific immunoblot strips. The frequency of specific IgG recognition to 12-13.5 and 33 kDa proteins of P. glabrum was significantly higher in HP patients. The sera of HP patients had significantly higher specific IgG recognition to 16 and 51-55 kDa proteins of C. sitophila. There was no specific IgE recognition in the sera of HP or asthmatic patients to both fungi.

CONCLUSIONS

Different patterns of antibody reactivity to P. glabrum and C. sitophila are seen in cork workers with hypersensitivity pneumonitis or asthma. The 12-13.5 and 33 kDa proteins of P. glabrum and the 16 and 51-55 kDa proteins of C. sitophila may be major antigens in Suberosis.

Qualitative and Quantitative Evaluation of Bird-Specific IgG Antibodies

BACKGROUND

Exposure to organic dust produced by birds often gives rise to an immune response, e.g. IgG antibodies, but intense exposure can lead to high concentrations of IgG antibodies and the development of allergic alveolitis, often known as "bird fancier's lung". The aim of this study was to establish the distribution of bird-specific IgG antibodies in exposed and nonexposed individuals and compare a nonquantitative and quantitative method in evaluating raised levels of IgG antibodies.

METHODS

Sera were collected in Sweden and South Africa and levels of IgG antibodies specific to pigeon, budgerigar and parrot antigens were quantified using the UniCAP system. Results were compared to the precipitation in gel assay. The IgG antibody values of symptomatic patients without precipitating antibodies (non-PP group; n = 51) and patients with precipitating antibodies (PP group; n = 34) were analyzed and compared to nonexposed asymptomatic blood donors (BD group; n = 73) and environmentally exposed pigeon breeders (n = 11).

RESULTS

The IgG antibody response of the analyzed groups in Sweden and South Africa did not vary significantly from each other. IgG antibody responses were the strongest to pigeon antigens with clear increased IgG antibody levels in the PP group [geometric mean (GM) 603 mg/l] compared to the non-PP (GM 6.9 mg/l) and BD group (GM 5.0 mg/l). Threshold values, calculated as the GM value from the BD group plus 3 standard deviations (99% confidence interval), were 9.8, 10.8 and 10.0 mg/l for pigeons, budgerigars and parrots, respectively. Comparison of the two methods resulted in a good concordance with a level of agreement of 94.1% (kappa statistic = 0.83).

CONCLUSIONS

The UniCAP system for the detection of bird-specific IgG antibodies is a highly reproducible, generally available, quantitative method for routine diagnostic testing and monitoring of exposed subjects with a very high level of agreement to the precipitating gel assay.

Serum CXCL9 and CCL17 as biomarkers of declining pulmonary function in chronic bird-related hypersensitivity pneumonitis

The clinical course of chronic hypersensitivity pneumonitis (HP) with fibrosis is similar to that of idiopathic pulmonary fibrosis (IPF). Current research is expected to identify biomarkers effective in predicting the deterioration of lung function in a clinical setting. Our group analyzed the relationships between the following parameters in chronic bird-related HP: patient characteristics, serum markers, lung function, HRCT findings, BALF profiles, and the worsening of lung function. We also analyzed serum levels of CXCL9, CCL17, and Krebs von den Lungen 6 (KL-6) as serum markers. Patients showing declines in vital capacity (VC) of over 5% at 6 months after first admission were categorized as the “decline group”; the others were categorized as the “stable group.” The serum level of CCL17 and the percentage of BALF macrophages were significantly higher in the decline group compared to the stable group. Serum levels of CXCL9 and CCL17 were significant variables in a multivariate logistic regression analysis of factors associated with VC decline. Patients with a chemokine profile combining lower serum CXCL9 and higher serum CCL17 exhibited significantly larger VC decline in a cluster analysis. Higher serum CCL17 and lower serum CXCL9 were important predictors of worsening lung function in patients with chronic bird-related HP.

TA-19, a novel protein antigen of Trichosporon asahii, in summer-type hypersensitivity pneumonitis

The most common form of hypersensitivity pneumonitis in Japan is summer-type hypersensitivity pneumonitis (SHP), which is caused by the inhalation of Trichosporon asahii or Trichosporon mucoides. To seek protein antigens relevant to the immunopathogenesis of SHP, we constructed a cDNA expression library of T. asahii, a major causative yeast species of SHP. Using the immunoscreening method, we identified and cloned a novel gene encoding a 19-kD protein, named TA-19, which proved to be specifically recognized in the bronchoalveolar lavage (BAL) fluids and sera of patients with SHP. IgG, IgA, and IgM antibodies to the recombinant TA-19 protein were significantly elevated in the sera as well as in the BAL fluids from SHP patients compared with those from non-SHP groups. This protein also induced SHP-specific proliferation of the mononuclear cells from both the peripheral blood and BAL. These results reveal that TA-19 derived from T. asahii may play a relevant role in specific cellular and humoral immune responses in patients with SHP.

Hypersensitivity pneumonitis resulting from Aspergillus fumigatus in a greenhouse

A 57-y-old female who had cultivated vegetables in a plastic greenhouse developed a case of hypersensitivity pneumonitis from Aspergillus fumigatus. This report exemplifies a potential hazard caused by a thermotolerant fungus, A. fumigatus, in a poorly constructed greenhouse.

A component of pigeon dropping extract that reacts specifically with sera of individuals with pigeon breeder's disease

A component of pigeon droppings has been demonstrated to react with sera of individuals with pigeon breeder's disease, a form of hypersensitivity pneumonitis, by crossed isoelectric focusing. Similarly, exposed but asymptomatic pigeon breeders do not exhibit antibody to this component, even though they possess significant levels of antibody to other components of pigeon droppings. Purification of this disease-specific component of pigeon dropping was attempted by preparative isoelectric focusing, gel filtration, and affinity chromatography on an immunoadsorbent prepared with asymptomatic antibody. After repeated passage over the affinity column, complete purification could not be achieved. A rabbit antiserum made against the partially purified component revealed the presence of at least one other component that did not react with either symptomatic or asymptomatic sera. Despite these contaminants, the disease-specific component was characterized as a single polypeptide having a molecular weight of approximately 50,000 daltons and having an isoelectric point between 3.5 and 5.1.

Up-regulation of L-selectin and E-selectin in hypersensitivity pneumonitis

BACKGROUND

Selectins are adhesion molecules that contribute to leukocyte recruitment into the tissue after an injury. Hypersensitivity pneumonitis (HP) is a lymphocytic alveolitis, and we hypothesized that the overexpression of selectins could play a role in this process.

PATIENTS AND MEASUREMENTS

We studied 16 patients with HP and 7 healthy control subjects (HCs). Sera and BAL selectins and tumor necrosis factor-alpha were determined by enzyme-linked immunosorbent assay, and cellular lung localization was determined by immunohistochemistry. Additionally, BAL L-selectin, and L-selectin-bearing T-lymphocytes analyzed by flow cytometry were evaluated in HP patients and in exposed but asymptomatic subjects (EAS).

SETTING

Tertiary referral center and immunohistochemistry laboratory.

RESULTS

Raised levels of E-selectin (mean [+/- SD], 178.9 +/- 30.5 vs 59.4 +/- 4.7 ng/mL, respectively; p < 0.001) and P-selectin (mean, 232.6 +/- 29.9 vs 67.6 +/- 14.2 ng/mL, respectively; p < 0.001) were detected in HP patient sera compared to control subjects, while L-selectin levels showed no differences between groups. Conversely, HP patients displayed a significant increase in levels of L-selectin found in BAL fluid compared with both HCs and EAS (11.0 +/- 1.7 vs 6.9 +/- 0.43 and 3.1 +/- 0.5 ng/mL, respectively; p < 0.05). The levels of E-selectin found in BAL fluid were similar in patients from both groups, and P-selectin was not detected. Percentage of CD3+CD62 L+ lymphocytes was lower in HP patients compared with EAS (2.33 +/- 0.8 vs 4.31 +/- 2.4, respectively; p = 0.05). By immunohistochemistry, L-selectin was detected in interstitial macrophages and polymorphonuclear cells, and E-selectin was detected in endothelial cells.

CONCLUSION

These findings demonstrate that L-selectin and E-selectin are up-regulated during the development of HP, suggesting that they may contribute to the increased traffic of lung inflammatory cells.

Significance of specific IgG against sensitizing antigens in extrinsic allergic alveolitis: serological methods in EAA

The aim of our study is to find differences in IgG in sera of potentially exposed and nonexposed individuals and to detect differences in concentrations of specific serum IgG among subjects with and without EAA. Seventy-two patients being followed for suspected interstitial lung disease were included. Specific IgG in sera were established by ImmunoCAP. Serum concentrations of Aspergillus fumigatus, Candida albicans IgG and mixture of moulds IgG were higher in subjects with exposure to relevant inhalation antigens (p<0.05). Patients exposed to parrot and mammal hair mixture had higher serum concentration of specific IgG (p<0.05). Subjects without exposure to mites had lower serum IgG to Dermatophagoides pteronyssinus, Dermatophagoides farinae, Dermatophagoides microceras and Glycophagus domesticus (p<0.05). Higher concentration of serum specific IgG may show previous exposure to this antigen. Even though mite specific IgG are not commonly tested in EAA patients, we suggest their immunomodulatory activity may influence susceptibility to other inhalation antigens.

Acute-phase reactants in experimental inhalation lung disease

An investigation on the occurrence and role of acute-phase reactants in experimental inhalation lung disease (ILD) was undertaken. Using an experimental model of ILD in which rabbits are exposed to aerosols of appropriate fungal spores, haptoglobin analysis was compared with depressions in arterial oxygen tension (PaO2) with time following challenge. Haptoglobin values of rabbits exposed to single 30-min aerosol challenges of Aspergillus terreus, demonstrated a significant (two- to three fold) increase 24-48 hr after challenge. Haptoglobin elevation was found to be a more reliable and consistent indicator of pulmonary inflammation than depression of PaO2. In an effort to determine the role of haptoglobin in this response, acute phase reactant levels were elevated either actively or passively. When rabbits with augmented haptoglobin levels were exposed to aerosol challenges with A. terreus, the typical depressions in PaO2 at 1-4 hr postchallenge were not observed. This indicated the plasma containing elevated acute-phase reactants may be involved in limiting the pulmonary response that normally occurs following challenge. Haptoglobin was not found to bind to A. terreus spores in vitro.

Acute autoimmune response in a case of pyromellitic acid dianhydride-induced hemorrhagic alveolitis

A 17-year-old man was occupationally exposed to pyromellitic acid dianhydride dust during the production of epoxy resin in a chemical factory. He was clinically diagnosed as having acute hemorrhagic alveolitis associated with anemia. The serologic analysis revealed a high concentration of IgG antibodies against pyromellitic acid dianhydride-treated human serum albumin (PMDA-HSA). Immunoblotting with PMDA-treated human serum as antigen and the patient's serum as the first antibody showed that additional PMDA-modified serum proteins other than HSA were recognized by the patient's IgG antibodies in the higher mol. mass range (> 67 kDa). No specific IgG could be detected against other anhydride conjugates (maleic acid, MA; phthalic acid, PA) with the exception of a reaction with the trimellitic acid anhydride-conjugated HSA (TMA-HSA). No specific IgE antibodies could be detected against any of the above mentioned antigens, but immunoblotting of the patient's serum indicated IgG4-type autoantibodies against in vitro PMDA-treated Ig molecules of normal serum proteins.

The Transcription Factor SCX is a Potential Serum Biomarker of Fibrotic Diseases

Fibrosing diseases are causes of morbidity and mortality around the world, and they are characterized by excessive extracellular matrix (ECM) accumulation. The bHLH transcription factor scleraxis (SCX) regulates the synthesis of ECM proteins in heart fibrosis. SCX expression was evaluated in lung fibroblasts and tissue derived from fibrotic disease patients and healthy controls. We also measured SCX in sera from 57 healthy controls, and 56 Idiopathic Pulmonary Fibrosis (IPF), 40 Hypersensitivity Pneumonitis (HP), and 100 Systemic Sclerosis (SSc) patients. We report high SCX expression in fibroblasts and tissue from IPF patients versus controls. High SCX-serum levels were observed in IPF (0.663 ± 0.559 ng/mL, p < 0.01) and SSc (0.611 ± 0.296 ng/mL, p < 0.001), versus controls (0.351 ± 0.207 ng/mL) and HP (0.323 ± 0.323 ng/mL). Serum levels of the SCX heterodimerization partner, TCF3, did not associate with fibrotic illness. IPF patients with severely affected respiratory capacities and late-stage SSc patients presenting anti-topoisomerase I antibodies and interstitial lung disease showed the highest SCX-serum levels. SCX gain-of-function induced the expression of alpha-smooth muscle actin (α-SMA/ACTA2) in fibroblasts when co-overexpressed with TCF3. As late and severe stages of the fibrotic processes correlated with high circulating SCX, we postulate it as a candidate biomarker of fibrosis and a potential therapeutic target.

Superoxide anion release from blood monocytes and alveolar macrophages in patients with diffuse lung fibrosis

Superoxide anion release (O2-) after stimulation with phorbol myristate acetate was measured in alveolar macrophages (AM) obtained by bronchoalveolar lavage and in blood monocytes from 47 patients with diffuse interstitial lung disease: idiopathic pulmonary fibrosis (N = 15), hypersensitivity pneumonitis (N = 7), pneumoconiosis (N = 6) and sarcoidosis (N = 19). Differential cell counts demonstrated a lymphocyte predominance in patients with hypersensitivity pneumonitis (HP) and sarcoidosis while the other groups had neutrophil predominance. No correlation between O2- activity in alveolar macrophages (AM) or blood monocytes (BM) compared to lung function (VC and diffusing capacity) could be demonstrated. Smoking pneumoconiotics had significantly decreased BM O2- release (1.25 +/- 0.25 (SEM) nmol/min/10(6) cells) and significantly increased AM/BM O2- ratios (2.04 +/- 0.26) compared to smokers with idiopathic pulmonary fibrosis (IPF) who had the following mean values: BM O2- release = 2.58 +/- 0.25 and AM/BM O2- ratio = 0.86 +/- 0.23. When matched for sex and smoking, a significantly increased AM/BM O2- ratio was seen among patients with HP (2.19 +/- 0.98) in comparison with patients who had sarcoidosis (0.40 +/- 0.18). Patients with either HP or pneumoconiosis had generally elevated AM O2- release and reduced BM O2- release. These results suggest that environmentally related interstitial lung disorders (HP and pneumoconiosis) may be associated with elevated AM O2- release relative to BM O2- release in comparison to non-environmentally related disorders (IPF or sarcoidosis).

A survey of P1-antibodies in Scottish pigeon fanciers

The incidence and characteristics of P1-antibodies in Scottish pigeon fanciers has been assessed. Of 223 individuals participating in the study, 23.3% were P1-negative and of these, 53.9% had detectable P1-antibodies. These antibodies were shown to belong to the IgM class and the highest serum levels were found in those pigeon fanciers with symptoms of respiratory disease who were sensitized to pigeon antigens. Of pigeon fanciers' sera, 10.3% gave false positive reactions for the Hepatitis B surface antigen in a reversed passive haemagglutination test. The reactions were most prevalent in sensitized fanciers and were shown to be directed not against the absorbed HBsAg antibody, but against the turkey red cells used as carriers in the test. No relationship was observed between the existence of P1-antibodies and false-positive hepatitis reactions. It was concluded that the inhalation of avian antigens by pigeon fanciers can induce the production of at least three distinct populations of antibodies. No evidence was obtained to imply any special role for P1-antibodies in the aetiology of pigeon fanciers' disease.