Inhalation challenge test using pigeon eggs for chronic hypersensitivity pneumonitis.

BACKGROUND: Chronic hypersensitivity pneumonitis (CHP) remains a diagnostic challenge. The process of collecting and extracting serum and droppings from causative animals for the inhalation challenge test is complicated and the risk of inducing disease progression exists. OBJECTIVE: To investigate the utility and safety of an inhalation challenge test using pigeon eggs. METHODS: Pigeon eggs were pasteurized and mixed with a saline solution to produce an inhalation fluid. An inhalation challenge test was conducted on 19 patients with bird-related CHP and 17 patients with interstitial lung disease other than bird-related CHP. To identify antigens in pigeon eggs, the antigen-antibody responses of the pigeon eggs and serum from patients were evaluated using Western blotting. RESULTS: The mean changes in C-reactive protein, alveolar-arterial oxygen difference, erythrocyte sedimentation rate, and lactate dehydrogenase significantly increased by 0.32 mg/dL (P = .014), 7.8 Torr (P = .002), 1.4 mm/h (P = .012), and 5.4 U/mL (P = .0019), respectively, in bird-related CHP group compared to the control 24 hours after the inhalation challenge test. Furthermore, within 24 hours of the inhalation test, the mean forced vital capacity decreased by 2.3% in the bird-related CHP group compared with a decline of 0.05% in the control group (P = .035). Serum collected from seven bird-related CHP patients who underwent the inhalation challenge test and reacted to antigens with molecular weights of 37-75 KDa, and these molecular weights were consistent with egg albumin and globulin. CONCLUSION: Since a mild response was observed after the inhalation challenge test using pigeon eggs, this test was an obvious candidate for diagnosing bird-related CHP.

Krebs von den Lungen-6 (KL-6) is a pathophysiological biomarker of early-stage acute hypersensitivity pneumonitis among pigeon fanciers.

BACKGROUND: Identifying early stages of hypersensitivity pneumonitis (HP) is hampered by variable presentation, heterogeneous or undetected causal antigens and lack of gold-standard biomarkers. Krebs von den Lungen (KL)-6 is pathophysiological biomarker of alveolar epithelial damage. Pigeon fanciers, susceptible to HP, provide a model to investigate early HP. OBJECTIVE: To test the hypothesis that plasma concentrations of KL-6 are increased in early-stage acute HP. METHODS: Clinical history, spirometry and blood samples were obtained from pigeon fanciers, 20 with intermittent acute symptoms indicative of developing HP, 27 with no symptoms and 10 healthy subjects with no avian exposure. Plasma KL-6 (units/mL) and pigeon antigen-specific IgG antibody were quantified by enzyme immunoassay. Blood lymphocytes were quantified by flow cytometry and antigen specificity by in vitro cytokine production. RESULTS: KL-6 was higher in fanciers than controls, median (IQR) 452 (244, 632) vs 274 (151, 377), P = .01. Although fanciers with symptoms had similar antigen exposure and lung function, they had higher KL-6 than those without, 632 (468, 1314) vs 320 (200, 480), P < .001. KL-6 correlated with IgG antibody titre in those with symptoms, r = .591, P = .006. High KL-6, irrespective of symptom category, was associated with higher antibody (P = .006) and lymphocyte proliferation (P = .041), and lower CD4+ T lymphocyte proportion (P = .032). CONCLUSION AND CLINICAL RELEVANCE: Raised KL-6 is associated with acute symptoms of early-stage HP, and its correlation with antibody may support therapeutic strategies when HP is suspected. KL-6 may act as a mechanistic biomarker of early pathogenesis by linking lung pathophysiological changes with an endotype of immune hypersensitivity.

Diagnostic accuracy and safety of inhalation challenge tests for bird fancier's lung-Systematic review and meta-analysis.

OBJECTIVE: To assess the diagnostic accuracy of inhalation challenge tests for bird fancier's lung and related adverse reactions. DESIGN: We performed a systematic review and meta-analysis for the diagnostic test accuracy of inhalation challenge tests and a systematic review for adverse events of the tests. We evaluated the risk of bias and applicability of the included articles for diagnostic test accuracy with the modified Quality Assessment of Diagnostic Accuracy Studies-2 tool. We used hierarchical summary receiver operating characteristic (HSROC) curve analysis to evaluate the sensitivity and specificity of challenge tests and assessed subjective adverse reactions and steroid treatment use. Sensitivity was calculated by fixing specificity at 99% from the HSROC curve. DATA SOURCES: We searched for articles evaluating the diagnostic accuracy of inhalation challenge tests or describing adverse reactions in Medline, Embase, the Cochrane Library, the International Clinical Trials Registry Platform, and Web of Science. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: We included randomized control trials, prospective or retrospective cohort studies, or case-control studies assessing the diagnostic test accuracy of inhalation challenge tests for bird fancier's lung. For adverse effects review, we included the same articles, and case series or case reports reporting adverse reactions of inhalation challenge tests. RESULTS: In our review of 12 articles, the diagnostic accuracy of inhalation challenge tests was substantially high. Point estimate of sensitivity when calculated with a fixed specificity of 99% was 99%. Among 873 patients, 6 needed steroid treatment for adverse reactions; however, no death occurred due to acute exacerbation following a challenge test. CONCLUSIONS: Inhalation challenges for bird fancier's lung could be accurate and safe diagnostic procedures and may be considered both as rule-in and rule-out tests in tertiary care centres. However, caution is required regarding overestimation of diagnostic yield due to risk of bias. Systematic review registration: University hospital Medical Information Network Clinical Trials Registry (UMIN000038799).

[Bird fancier's disease in a child: about a rare and unusual case]. / La maladie du poumon des éleveurs d´oiseaux chez un enfant: à propos d´un cas rare et inhabituel.

Bird fancier's disease falls within the spectrum of hypersensitivity pneumonitis secondary to immuno-allergic reaction to avian antigens. This occurs only rarely in children. It is found in two-thirds of patients with hypersensitivity pneumonitis. Diagnosis is not so easy. It is based on a body of clinical evidence. We here report the peculiar case of a 7-year-old girl with a family history of atopic disease initially treated as asthma based on the presence of wheezing and dyspnea and cough without improvement. The patient had worsening of symptoms such as dyspnea at rest complicated by cyanosis in respiratory distress. All of this took place in a context of alteration of general state. Clinical examination showed growth retardation, perioral cyanosis with digital hippocratism. Lung auscultation revealed bilateral crackling sounds. Chest X-ray objectified bilateral interstitial syndrome. Chest computed tomography (CT) scan showed diffuse ground-glass opacities. Laboratory tests revealed hypereosinophilia with hyper-IgE and excluded tuberculosis, cystic fibrosis, immune deficiency. In a second stage interview contact with birds was reported. Serological tests for bird fancier's disease were positive. The patient received inhaled corticosteroids associated with avoidance of exposure to birds. After a follow-up of 2 months, outcome was favorable. Given that the signs of bird fancier's disease are non-specific, this should be suspected in patients with respiratory symptoms associated with exposure to avian antigens.

Periostin as a predictor of prognosis in chronic bird-related hypersensitivity pneumonitis.

BACKGROUND: Periostin is an established biomarker of Th2 immune response and fibrogenesis. Recent research has indicated that periostin plays an important role in the pathogenesis of idiopathic interstitial pneumonias. To clarify the relationship between periostin and pathogenesis in chronic bird-related hypersensitivity pneumonitis (HP) and to reveal the usefulness of serum periostin levels in diagnosing and managing chronic bird-related HP. METHODS: We measured serum periostin in 63 patients with chronic bird-related HP, 13 patients with idiopathic pulmonary fibrosis, and 113 healthy volunteers. We investigated the relationship between serum periostin and clinical parameters, and evaluated if the baseline serum periostin could predict the prognosis. RESULTS: Serum periostin was significantly higher in patients with chronic bird-related HP compared to the healthy volunteers. In chronic bird-related HP, serum periostin had significant positive correlations with serum KL-6 levels, the CD4/CD8 ratio in bronchoalveolar lavage fluid, and fibrosis score on HRCT, and a significant negative correlation with the diffusing capacity of the lungs for carbon monoxide. Chronic bird-related HP patients with serum periostin levels exceeding ≥92.5 ng/mL and ≥89.5 ng/mL had a significantly worse prognosis and significantly higher frequency of acute exacerbation, respectively. Higher serum periostin (92.5 ng/mL or higher; binary response for serum periostin) was an independent prognostic factor in multivariate analysis. CONCLUSIONS: Serum periostin may reflect the extent of lung fibrosis and play an important role in pathogenesis of chronic bird-related HP. Elevated serum periostin could be a predictor of prognosis in patients with chronic bird-related HP.

Immunization of BALB/c mice with pigeon IgY induces the production of anti-IgG autoantibodies.

The breakdown of immunological tolerance due to the activation of autoreactive B and T cells triggers physiopathological processes. An example of such conditions is the production of IgG autoantibodies specific for the Fc portion of IgG (anti-Fcγ IgG). Previous reports have shown that patients with pigeon-related hypersensitivity pneumonitis exhibit an increase in the serum levels of anti-Fcγ IgG. There is no in vivo model for the study of this condition and the immunological mechanisms of tolerance breakdown associated with sensitization by pigeon antigens are still unknown. In this work, we show that the repeated immunization of BALB/c mice with pigeon IgY during 16-weeks induces the production of anti-Fcγ IgG and keeps their high levels for seven weeks. The late appearance of anti-Fcγ IgG autoantibodies in the plasma is similar to what has been reported in other experimental autoimmune models. With the occurrence of anti-Fcγ IgG, there is a reduction in the proportion of Foxp3 + cells (regulatory T cells, Tregs) within the population of splenic CD4 + CD25 + T cells. Thus, our data showed that the immunization of BALB/c mice with IgY promotes the production of anti-Fcγ IgG along with a decrease in Tregs in the spleen. We propose that immunization of mice with pigeon antigens, like IgY can provide a model to study the immunological mechanisms involved in the development of pigeon-related hypersensitivity pneumonitis.

Utility of Exhaled Nitric Oxide Fraction for the Diagnosis of Hypersensitivity Pneumonitis.

BACKGROUND: There is very little evidence of the utility of the exhaled fraction of NO (FeNO) for the diagnosis of interstitial lung disease and nearly all of it is related with connective tissue disease. Some authors have suggested that in patients with hypersensitivity pneumonitis (HP), evolution to pulmonary fibrosis may be mediated by a Th2 mechanism, which could redound in a potential utility of FeNO. The aim of this study was to investigate the values of FeNO before and after antigenic exposure with the specific inhalation challenge (SIC) and to analyze its potential utility for the diagnosis of HP. METHODS: It was a prospective, cross-sectional study of all patients older than 18 years referred to our center for suspected chronic HP between May 2012 and May 2014 and who underwent a SIC. FeNO was collected before and after SIC. RESULTS: The study sample comprised 25 patients. Eleven were diagnosed with chronic HP; six had been exposed to avian proteins and five to fungal agents. Of these 11 patients, seven had positive SICs. In the 14 patients with diagnoses other than HP, all the SICs were negative. No significant differences in baseline characteristics were observed according to HP diagnosis, except in the BAL lymphocyte count. No differences were found after the test in patients diagnosed with HP; nor were there differences in baseline FeNO in patients diagnosed with HP and those who received alternative diagnoses. CONCLUSIONS: The results suggest that FeNO measurement is not useful for the diagnosis of chronic HP.

Bird fancier's lung: clinical-radiological presentation in 15 cases.

INTRODUCTION: Bird fancier's lung (BFL) is a type of hypersensitivity pneumonitis occurring in response to avian antigens (usually inhaled proteins in bird feathers and droppings). The diagnosis is based on a combination of clinical, radiological, and biopsy characteristics. The present study was planned to highlight the clinico-radiological presentation in cases of BFL. MATERIAL AND METHODS: The present study is a retrospective analysis of cases of bird fancier's lung diagnosed in a unit of Vallabhbhai Patel Chest Institute over a period of two years, from 2013-2014. The clinico-radiological features of the subjects were analysed. The diagnosis of BFL was made as per criteria laid down by Mark Schuyler and Yvon Cormier. RESULTS: There were a total of fifteen cases diagnosed with BFL during the study period, comprising twelve females and three males with a mean age of 54.93 ± 14.21 years. All the studied subjects gave significant history of exposure to pigeons and were non-smokers. The period of symptoms prior to presentation varied from one to eight years. The main symptoms on presentation were exertional breathlessness and cough. Radiologically, diffuse centrilobular nodules, ground glassing - diffuse or patchy predominant in upper lobes, fibrosis with or without traction bronchiectasis, honeycombing, and mediastinal lymphadenopathy were seen. Bronchoscopy showed ill-defined granulomas and chronic interstitial inflammation. CONCLUSIONS: BFL can exhibit a wide range of radiological patterns, and a high index of suspicion must be maintained, with particular attention to detailed exposure history in every case of interstitial lung disease.

The prevalence of "pigeon breeder's disease" in a Turkish city and review of the literature.

Hypersensitivity pneumonitis (HP) is a rarely encountered inflammatory interstitial lung disease caused by various antigens. Studies in the literature report contradictory rates about its prevalence. The aim of the present study was to determine the prevalence of "pigeon breeder's disease" (PBD) among pigeon breeders in Samsun province. The present study was performed in two phases. In the first phase, we contacted the Samsun Serinofil Association (Samsun Serinofil Dernegi) and a detailed questionnaire was given to the pigeon breeders to fill out. In the second phase, advanced diagnostic tests such as chest X-ray, high-resolution chest computed tomography, pulmonary function tests, natural provocation, bronchoalveolar lavage (BAL), and transbronchial lung biopsy (TBLB) were used to verify the diagnosis in those suspected with PBL. The questionnaire was administered to 185 male volunteers, of whom 11 had suspicious findings. Of eight subjects in whom the natural provocation was performed, one had a positive (acute PBL) response. After discontinuation of exposure, clinical improvement was observed in the second subject (subacute HP), of whom the radiological findings, BAL, and TBLB results were consistent with PBL. The third subject, who had dyspnea for 28 years, was diagnosed with chronic PBL. Consequently, the prevalence of PBL and the positivity of the natural provocation were 1.6 and 12.5%, respectively. In the present study, in which the prevalence of PBL was determined using natural provocation for the first time, the prevalence of HP (1.6%) was quite low compared with previous studies. The present study has demonstrated that a study solely based on a questionnaire is not adequate in determining the prevalence of HP.

Presenting features of feather duvet lung.

BACKGROUND: Feather duvet lung (FDL) is a rare subgroup of bird fancier's lung. It is caused by inhalation of organic dust due to goose or duck feathers in duvets or pillows. METHODS: A retrospective review of the medical records of 13 patients with FDL was performed to assess the specific history and review clinical characteristics of patients with this disease. RESULTS: All patients were female with a mean age of 53 years (26-71). They were recently exposed to feather duvets (6), pillows (1) or both (6). Specific histories were duvets or pillows filled with raw goose feathers from their own farms (4), intensive contact with goose feathers in youth (3), and bird exposure prior to symptom onset (5). In all patients specific IgG antibodies to goose and/or duck feathers were detected. Pulmonary function tests revealed a moderate to severe reduced diffusion capacity and a mild restrictive pattern. High-resolution computed tomography was performed in 11 patients and demonstrated predominantly ground-glass opacities (10) and fibrosis (6). In bronchoalveolar lavage fluid, lymphocytic alveolitis was demonstrated in all patients. Lung biopsies were obtained in 9 patients and demonstrated lymphocytic alveolitis (8), granulomas (3), bronchiolitis obliterans organizing pneumonia pattern (2), and usual interstitial pneumonia pattern (1). CONCLUSIONS: The clinical findings of FDL are typical of extrinsic allergic alveolitis. Primary sensitization could be due to former exposure to bird antigens at home or goose/duck feather exposure in youth. In view of the increasing popularity of feather duvets, FDL should be considered in the differential diagnosis of patients with extrinsic allergic alveolitis.

[Bird-related chronic hypersensitivity pneuminitis demonstrating the fluctuation of disease activity accompanied with environmental changes].

We report a case of bird-related chronic hypersensitivity pneuminitis exhibiting the fluctuation of serum markers for interstitial lung disease along with the changes in life environment. A 65-year-old man had had an abnormal chest radiograph for 2 years and had complained of a non-productive cough. He had had 30 parakeets 20 years previously and had used feather products for 15 years. In autumn and early winter wild birds had visited persimmons trees in the neighboring garden. Antibodies to bird-related antigens in the broncho-alveolar lavage fluids and sera were positive and the thoracoscopic lung biopsy specimens histologically revealed airway-centered fibrosis. We then determined he was having bird-related chronic hypersensitivity pneumonitis. After avoidance of feather products, all of serum SP-A, SP-D and KL-6 decreased. But three markers elevated and radiographic findings worsened accompanied with the increase of visiting wild birds in next autumn. After pruning persimmon trees and starting corticosteroid with cyclosporine, disease activity gradually improved.

Hypersensitivity pneumonitis as a cause of airway-centered interstitial fibrosis.

BACKGROUND: Airway-centered interstitial fibrosis (ACIF) has been postulated to be related to environmental exposures. OBJECTIVE: To describe a patient with ACIF associated with hypersensitivity pneumonitis. METHODS: We evaluated a patient with a 2-year history of progressive dyspnea and exercise intolerance. We performed computed tomography, pulmonary function tests, and skin prick tests. RESULTS: The patient's computed tomogram suggested hypersensitivity pneumonitis. Pulmonary function testing demonstrated a restrictive pattern. Results of skin prick tests to chicken, goose, canary, and budgie were negative. However, serum precipitins were positive to serum from pigeon, goose, duck, and chicken feathers. The patient was diagnosed as having ACIF. CONCLUSION: We believe that ACIF may represent a final common pathway for lung injury due to environmental exposure.

Nerve growth factor in serum and lymphocyte culture in pigeon fanciers' acute hypersensitivity pneumonitis.

BACKGROUND: Nerve growth factor (NGF) is a neurotrophic cytokine with immunomodulatory activity. NGF contributes to neurogenic inflammation and has been described in asthma and idiopathic pulmonary fibrosis. OBJECTIVES: To identify and quantify NGF in serum and peripheral blood lymphocyte cultures from pigeon fanciers, and to investigate an association with the immune response to inhaled avian antigens, and with symptoms of acute hypersensitivity pneumonitis (HP). METHODS: NGF was quantified and compared with serum IgG antibody against inhaled avian antigens, with serum C-reactive protein (CRP), and with KL-6, a marker of lung interstitial inflammation. These were measured using enzyme-linked immunoassay. Levels were compared with symptom history in 55 pigeon fanciers (26 subjects with acute HP but symptom-free at the time of testing) and 15 subjects with no avian exposure. RESULTS: Pigeon fanciers had higher-than-normal serum IgG antibody, CRP, and KL-6 levels (p < 0.01 each). These measures were unrelated to HP symptom category; instead, in all pigeon fanciers, the concentrations of CRP and KL-6 correlated with each other and with the antibody titers (p < 0.01 each). Serum NGF levels were normal; however, NGF production by mitogen-activated lymphocytes was higher than normal, and correlated with IgG antibody titer (p < 0.05) and with serum CRP (p < 0.05). CONCLUSIONS: Serum NGF was normal in pigeon fanciers; however, their blood lymphocytes ex vivo synthesized increased NGF in concentrations that correlated with the titer of serum IgG antibody to inhaled avian antigens. These also correlated with CRP and KL-6 levels, suggesting that antigen exposure in seropositive subjects is associated with subclinical inflammation involving coordinated synthesis of neurotrophin and immune mediators.

Hypoxemia: an early indication of pigeon breeders' disease. Clinical and laboratory findings among pigeon breeders in the Salonica area.

The purpose of this study is to identify pathological findings among pigeon breeders in the Salonica area. Fifty-four volunteer breeders with varying intensity of contact with pigeons participated in the study. All the breeders, after filling in a questionnaire that included questions about the existence of conjunctivitis, rhinitis, chronic cough and sputum, were subjected to clinical examination and spirometric, hematological (arterial and venous), radiographic and immunologic tests. Twenty-five point nine percent of the breeders suffered from conjunctivitis, 31.5% from rhinitis and 33.3% from chronic cough and sputum. Fourteen point eight percent of them had class I precipitins, 7.4% had class II, 5.6% had class III and 16.7% had class IV and a positive correlation of precipitin class with the number of pigeons bred was found. Seven breeders (13%) had hypoxemia at rest and other 8 (14.8%) presented with hypoxemia after the exercise testing. Two breeders presented with a combination of findings of allergic alveolitis that satisfied the criteria of the Pigeon Breeders' Disease (PBD). A substantial number of the examined pigeon breeders were sensitized to pigeon serum antigens. Arterial hypoxemia, either at rest and/or after exercise was observed in 27.8% of breeders. Three point seven percent of breeders presented with clinical and laboratory findings consistent with PBD. Chronic cough and sputum in pigeon breeders should be considered as a possible manifestation of PBD.

Chronic bird fancier's lung presenting with acute exacerbation due to use of a feather duvet.

A 67-year-old man was admitted due to fever and exertional dyspnea. He used to raise budgerigars and hill mynahs from 1980 to 1988. He was diagnosed as having chronic bird fancier's lung (BFL) based on a positive peripheral lymphocyte proliferation to pigeon serum in 1994. His disease was stable until 2000. Three months before admission he became a daily user of a feather duvet. A chest CT showed newly-developed peribronchial ground-glass opacities and preexisting honeycombing. Inhalation provocation test was positive. Administration of steroids improved his condition. He has been well after refraining from the use of the feather duvet.

[Suberosis and bird fancier's disease: comparative study of radiological, functional and bronchoalveolar characteristics profile]. / Suberose e doença dos criadores de aves: estudo comparativo do perfil radiológico, funcional e do lavado broncoalveolar.

Extrinsic Allergic Alveolitis (EAA) 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 has 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 EAA seen in our practice: Suberosis 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 EAA had lymphocytic alveolitis in BALF: Suberosis - 6.6 +/- 5.7 x 105 ml-1 cells, 58.8 +/- 18.9% lymphocytes; bird fancier's disease - 9.0 +/- 6.5 x 105 ml-1 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 EAA 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.

Clinical features of recurrent and insidious chronic bird fancier's lung.

BACKGROUND: Chronic bird fancier's lung (BFL) can be subgrouped into two types. One subgroup of patients develops interstitial pulmonary fibrosis after recurrent acute episodes (recurrent BFL), and the other subgroup of patients has no history of acute episodes but has slowly progressive chronic respiratory disease (insidious BFL). OBJECTIVE: To define the clinical characteristics of both types of BFL and to provide clues for diagnosis. METHODS: We performed a retrospective review of the medical records of patients with chronic BFL who were evaluated between October 1992 and March 2001 at the Tokyo Medical and Dental University Hospital in Japan. Patients were evaluated for their clinical characteristics, including history, laboratory, and immunologic findings; imaging; bronchoalveolar lavage; and histologic findings. RESULTS: Thirty-two patients with chronic BFL were included in this study; 15 patients had recurrent BFL and 17 had insidious BFL. The patients with recurrent BFL tended to breed dozens of pigeons in a loft, whereas the patients with insidious BFL were likely to be exposed to smaller birds kept indoors. Specific antibodies against pigeon dropping extracts or budgerigar dropping extracts were positive in 87% of the recurrent BFL cases and 35% of the insidious BFL cases. Antigen-induced lymphocyte proliferation was positive in more than 90% of both groups. The upper lung field was frequently involved in both groups as demonstrated by chest radiographic findings. In all of the patients with insidious BFL, the diagnosis was confirmed by positive laboratory-controlled inhalation test results. CONCLUSIONS: Insidious BFL may be misdiagnosed as idiopathic pulmonary fibrosis if a careful history is not taken and antigen-induced lymphocyte proliferation, careful imaging evaluation, and laboratory-controlled inhalation challenge testing are not conducted. In contrast, the clinical findings of recurrent BFL are consistent with hypersensitivity pneumonitis induced by other antigens.

The long-term outcome in acute, subacute, and chronic forms of pigeon breeder's disease hypersensitivity pneumonitis.

BACKGROUND: Pigeon breeder's disease (PBD) is an avian-induced hypersensitivity pneumonitis. The limited data that exist on the long-term outcome for the disease are conflicting. OBJECTIVE: We sought to determine the long-term outcome of patients with PBD to evaluate the course of the disease. METHODS: Review a case series of 18 pigeon breeders that were followed from 4 to 26 years after initial diagnosis. RESULTS: Fourteen breeders reduced their bird contact significantly; four kept their birds. In eight patients with the acute form of the disease, pulmonary function either did not change from normal or improved to normal. Of five patients with subacute disease, four had persistent symptoms. All had mildly abnormal spirometry with either restrictive or obstructive changes which persisted. Five patients with chronic disease exhibited daily dyspnea. They had severe abnormalities of lung function at diagnosis. Of these patients, three improved and two deteriorated. Chest radiographs were of little value in predicting outcome. CONCLUSIONS: Patients with the acute form of PBD have the best prognosis, compared with those with subacute and chronic forms. Although some improvement could be seen in most individuals, recovery may still not be complete. Those with the chronic form are at particular risk for morbidity.

Inhalation provocation tests in chronic bird fancier's lung.

BACKGROUND: Patients with chronic bird fancier's lung (BFL) can be classified into two types. One group of patients develops chronic disease with fluctuating acute episodes, including low-grade fever, mild exertional dyspnea, and cough (fluctuating chronic BFL; formerly termed recurrent and relapsing chronic BFL). The other group of patients shows no history of acute episodes (insidious chronic BFL). The diagnosis of chronic BFL is difficult, since the onset of chronic BFL may be insidious, with few if any symptoms during the early stages of the disease process. STUDY OBJECTIVE: To attempt to diagnose the conditions of these patients more precisely, inhalation provocation tests were conducted using avian dropping extracts. DESIGN: Retrospective chart review. SETTING: The Tokyo Medical and Dental University Hospital in Japan. PATIENTS: Eleven patients with chronic BFL (6 with fluctuating chronic BFL and 5 with insidious chronic BFL) and 6 control subjects (4 asymptomatic bird owners and 2 idiopathic pulmonary fibrosis patients) were evaluated. MEASUREMENTS AND RESULTS: Inhalation provocation tests using avian dropping extracts were conducted. All BFL patients were evaluated as positive or probable by inhalation challenge, whereas control subjects were evaluated as negative. A peripheral leukocytosis, an increase of alveolar-arterial oxygen pressure difference, an increase of body temperature, and the development of respiratory symptoms including cough and dyspnea were more frequently observed in chronic BFL patients than in control subjects. All the BFL patients had an increase in neutrophils in BAL fluids following inhalation challenge. CONCLUSIONS: We validated the utility of inhalation challenge for the diagnosis of chronic BFL, including fluctuating and insidious BFL. We also demonstrated that neutrophilia in BAL fluids following inhalation challenge could be added to the diagnostic criteria for chronic BFL.