Pigeon allergens in indoor environments: a preliminary study

Airborne methicillin-resistant Staphylococcus aureus, other bacteria, fungi, endotoxin, and dust in a pigeon exhibition

Pigeon breeding is associated with exposure to airborne microorganisms and endotoxin and with symptoms of the airways. Antibiotic resistance is a threat to human health. Some pigeons participate in national and international indoor exhibitions. This study aims to obtain knowledge about the potential human exposure to dust, endotoxin, fungi, and bacteria including the methicillin-resistant Staphylococcus aureus (MRSA) in a pigeon exhibition in Denmark. In walking areas for visitors, airborne microorganisms in different size fractions able to enter the airways were sampled and following identified. The average concentrations were: 5000 cfu fungi/m³, 1.8 × 10⁴ cfu bacteria/m³, 37 endotoxin units/m³, and 0.18 mg dust/m³ air with the highest concentrations in-between rows with pigeon cages. The fungal species Wallemia sp. and Aspergillus versicolor and the bacterial species S. equorum and S. aureus were found in high concentrations. MRSA spa type t034 described to be associated with livestock was found in the air. Most of the S. aureus was present in the size fraction of 1.1-2.1 μm, which are particles able to enter the human terminal bronchi. In conclusion, fungi, bacteria, and endotoxin, respectively, were found in concentrations 10, 2000, and 200 times higher than outdoor references. The airborne bacteria in the exhibition were mainly species found previously in pigeon coops showing that the pigeons are the sources of exposure. The presence of airborne MRSA in the pigeon exhibition highlights the importance of also considering this environment as a potential place of exchange of resistant bacteria between animals and between animals and humans.

A rapid test for the environmental detection of pigeon antigen

INTRODUCTION

Avoidance of inhaled bird antigens is essential to prevent hypersensitivity pneumonitis disease progression. The aim of the present study was to develop a sandwich enzyme link immunoassay (ELISA) and an immunochromatographic test (ICT) and compare their ability to detect pigeon antigens in environmental samples.

METHODS

An amplified sandwich ELISA using pigeon serum as a calibration standard and a ICT using gold-labeled anti-pigeon serum antibodies for the rapid detection of pigeon antigens in environmental samples were developed. Twenty-two different airborne samples were collected and analysed using both methods. Strip density values obtained with ICT were calculated and compared with the concentrations determined by the ELISA method for pigeon antigens. Strips results were also visually analysed by five independent evaluators.

RESULTS

The ELISA method to quantify pigeon antigen had a broader range (58.4 and 10,112.2 ng/ml), compared to the ICT assay (420 to 3360 ng/ml). A kappa index of 0.736 (p < 0.0001) was obtained between the observers evaluating the ICT strips. The results of the ELISA and the relative density of the ICT showed a highly significant correlation (rs:0.935; p < 0.0001). Bland-Altman plot also confirmed excellent agreement between the two methods (mean difference: -1.626; p < 0.0001).

CONCLUSIONS

Since there was a good correlation between both assays, we can conclude that the rapid and simple ICT assay is a good and valid alternative, which does not require expensive equipment, for the validated ELISA technique.

Expression profile of MUC1 protein in Pigeon allergens positive asthmatic

BACKGROUND

Certain urban areas could contain many pigeon's allergens, which may play an imperative role in the exacerbation of asthma in pigeon allergen sensitive asthma patients. The circulating form of MUC1 in human serum has been considered as a biomarker for some allergic diseases. The study aimed to investigate the role of MUC1 in pigeon allergens positive asthma patients.

METHODS

We were enrolled 200 asthma patients including 81 males and 119 females. After positive pigeon exposure history, 108 patients underwent SPT testing against pigeon allergens (dropping and feather). A total of 17 patients, who had exposure history with SPT positive were undergone detail clinical examination. Serum MUC1expression analysis was done by western blotting method.

RESULTS

Out of 200 asthmatic patients, 108 (54%) patients had a history of exposure to pigeons. Skin prick test against pigeon (feather & dropping) allergens was positive in 17 (15.7%) patients among exposure asthmatics. The mean age of the study population was 28.8 ± 10.4 years with 9 males and 8 females. Baseline airway obstruction was seen in 58.8% cases. Out of 17 pigeons expose and sensitive asthmatic the MUC1 expression was up-regulated in 15 (88.2%) and down-regulated in 2 (11.8%). The mean value MUC1 fold change of 15 patients with up-regulation was 4.63 ± 3.00 fold.

CONCLUSION

MUC1 expression was up-regulated in 88.2% of patients, who were exposed and sensitive to pigeon allergen (dropping and feather). MUC1 may consider as a biomarker in pigeon sensitive asthma patients.

Ectoparasites and Intestinal Helminths of Pigeons in Medina, Saudi Arabia

The prevalence of ectoparasites and intestinal helminths of different pigeon taxa in Medina, Saudi Arabia, with special emphasis on the feral pigeon, Columba livia domestica (Columbiformes: Columbidae), was evaluated. Fifty-four pigeons were examined externally for ectoparasites and 28 feral pigeons were examined for helminths. Two ectoparasites were recorded on feral C. l. domestica (Harami) pigeons, including the shaft louse Menopon gallinae (Phthiraptera: Menoponidae), and the pigeon fly, Pseudolynchia canariensis (Diptera: Hippoboscidae), with 100 and 88.90% prevalence, respectively. Ectoparasites were also collected from 5 other breeds of C. l. domestica (Pakistani, Farensi, Turki, Kori, and Qatifi). Menopon gallinae infected Pakistani, Farensi, and Turki pigeons with 100% prevalence. A third ectoparasite, the brown poultry louse, Goniodes dissimilis (Psocodea: Philopteridae), infected Farensi, Turki, and Kori pigeons at rates of 100, 50, and 50%, respectively. Qatifi pigeons were not infected with any ectoparasites. Two types of intestinal helminths were recovered from feral pigeons: cestodes of Raillietina spp. (Cyclophyllidea: Davaineidae) and nematodes of Ascaridia sp. (Ascaridida: Ascaridiidae) (with 10.71 and 3.57% prevalences, respectively). To the best of our knowledge, this is the first study to shed light on the parasites of pigeons in Medina, Saudi Arabia.

Feeding ecology of blue rock pigeon (Columba livia) in the three districts of Punjab, Pakistan

Present paper provides information on the feeding regimens of the two genders of the blue-rock pigeon (Columba livia Linn.) in the sampled habitats of the three districts viz. Rawalpindi, Faisalabad and Bahawalpur of the Punjab province, Pakistan. This feral pigeon, considered ubiquitous species, inhabits both the grasslands and clumped environments to establish their roosts and nests. The study explored about comparable feeding proportions from three major habitats of the pigeons which were captured with medium sized mist-nets. For Rawalpindi in the winter season, the Zea mays was one of the predominant food item (30.6%) for males, and other ranked major food contents were (26.7%, 22.4% and 20.2%), and fairly similar feeding proportions were also recorded for the females (50.4%, 33.3%, 36.4% and 23.9%) for Carthamus oxyacantha, Hordeum vulgare, Triticum aestivum and Zea mays respectively. Evidently, no significant deviations in the existing food crops for the three sites for the feral pigeon were detected, which strongly suggested that the, modes of feeding habits among the sustainable roosts and nests which were closely located to food crops, exerted negligible impacts during intermittent pigeon foraging movements in the diurnal conditions.

Environmental levels of avian antigen are relevant to the progression of chronic hypersensitivity pneumonitis during antigen avoidance

Background

In chronic hypersensitivity pneumonitis (chronic HP), antigen avoidance is critical for disease management; however, complete avoidance is difficult because of unrecognized exposure to antigens. Recently, we revealed that the amount of avian antigen (AAA) in household dust at the time of diagnosis predicted the progression of chronic bird‐related HP. The purpose of this study is to evaluate the relationship between the prognosis of chronic bird‐related HP and the AAA that remained in the environment during antigen avoidance.

Methods

First, we measured the AAA in household dust of 28 consecutive patients (22 with chronic bird‐related HP and 6 with acute bird‐related HP) and 12 healthy volunteers. Second, we measured the AAA and collected questionnaires on the environmental conditions of the homes of 53 patients with various lung diseases, including bird‐related HP, to investigate the environmental parameters related to a higher AAA. Finally, we prospectively recruited 14 consecutive patients with chronic bird‐related HP, measured the AAA periodically, and collected clinical data.

Results

The AAA was higher in patients with chronic bird‐related HP at the time of diagnosis compared to healthy volunteers and was highest in patients with acute bird‐related HP. Logistic regression analysis showed that birds frequenting a residence was the only significant factor for a higher AAA (odds ratio, 5.686; 95%CI, 1.263–25.59; P = 0.024). There was a correlation between the mean AAA and decline of vital capacity for 1 year (r = −0.55; 95%CI −0.84 to −0.01; P = 0.043).

Conclusion

Measurements of the AAA after diagnosis predict the progression of chronic bird‐related HP. Avian antigen can exist in the indoor environment regardless of antigen avoidance. The presence of avian antigen in the indoor environment can be attributed to wild birds found outdoors.

The amount of avian antigen in household dust predicts the prognosis of chronic bird-related hypersensitivity pneumonitis

RATIONALE

Bird-related hypersensitivity pneumonitis is induced by inhalation of avian antigen. Evaluation to avoid repeated exposure to avian antigen is a key part of the treatment for bird-related hypersensitivity pneumonitis. It can be difficult, however, to reliably evaluate exposure to the antigen because bird-related hypersensitivity pneumonitis in its chronic form may be caused by unrecognized and indirect exposure.

OBJECTIVE

The purpose of the present study is to establish a method for measuring environmental avian antigen in patients with chronic bird-related hypersensitivity pneumonitis and to evaluate the clinical utility of the method.

METHODS

The amount of avian antigen was measured in samples of dust collected from the household environments of patients with chronic bird-related hypersensitivity pneumonitis. The patients whose clinical progress could be followed by periodic pulmonary function tests for 1 year were classified into a deterioration group and a stable group. Age, sex, smoking status, FVC % predicted, and the amount of avian antigen in household dust samples at the diagnosis of bird-related hypersensitivity pneumonitis, as well as survival, were determined and evaluated for each group. The total number of subjects was 23.

MEASUREMENTS AND MAIN RESULTS

The clinical condition deteriorated in 11 patients and remained stable in 12. The amount of avian antigen in household dust samples was significantly higher for the deterioration group than for the stable group. In logistic regression analysis, avian antigen was the only variable found to be significant for distinguishing between the two groups. The patients with higher amounts household dust avian antigen had a poor prognosis in the survival analysis. Avian antigen was the only variable to significantly influence the prognosis of chronic bird-related hypersensitivity pneumonitis.

CONCLUSIONS

The levels of exposure to avian antigen were related to disease progression and prognosis in chronic bird-related hypersensitivity pneumonitis.

Chronic hypersensitivity pneumonitis in patients diagnosed with idiopathic pulmonary fibrosis: a prospective case-cohort study

BACKGROUND

The clinical features of idiopathic pulmonary fibrosis (IPF) and chronic hypersensitivity pneumonitis can be indistinguishable; the need to eliminate occult environmental factors known to cause pulmonary fibrosis in patients suspected to have IPF during diagnostic evaluation is evident. We aimed to investigate occult, putative causes in the environments of patients diagnosed with IPF using tests beyond those conventionally used.

METHODS

In this case-cohort study, 60 consecutive patients diagnosed with IPF on the basis of the 2000 American Thoracic Society (ATS) and the European Respiratory Society (ERS) criteria were prospectively followed up every 4 months for 6 years between Jan 1, 2004, and Dec 31, 2009. At each visit a uniformly applied questionnaire was administered to these 60 patients to identify occult antigen exposure known to cause hypersensitivity pneumonitis. Patients underwent specific IgG determination, bronchoalveolar lavage, bronchial challenge testing with suspected antigens, and re-review of histopathological features in existing and subsequently obtained surgical lung biopsy samples and from lung explants. Specimens obtained from suspected sources from the patient's environment were subjected to cultures in microbiology laboratory. These clinical data and discussions among pulmonologists and radiologists familiar with IPF were used to confirm the diagnosis in accordance with 2011 ATS, ERS, Japanese Respiratory Society, and Latin American Thoracic Association guidelines; 46 of the 60 patients had IPF according to the 2011 guidelines, and our analyses in this study were focused on these 46 patients.

FINDINGS

20 of the 46 (43%, 95% CI 29-58) patients with IPF according to 2011 guidelines had a subsequent diagnosis of chronic hypersensitivity pneumonitis: nine patients had positive bronchial challenge testing (eight of whom were also IgG positive and six of these patients also had surgical lung biopsy showing a pattern consistent with chronic hypersensitivity pneumonitis); seven were IgG positive plus had histopathology on surgical lung biopsy that was consistent with hypersensitivity pneumonitis; one was IgG positive plus had greater than 20% lymphocytes in bronchoalveolar lavage fluid; and three had findings on surgical lung biopsy that were consistent with subacute hypersensitivity pneumonitis (and IgG positive). Altogether, 29 of 46 patients diagnosed with IPF who had met the 2011 criteria had lung tissue available for histopathology (surgical lung biopsy in 28 patients and explanted lung in two patients, one of whom also had surgical biopsy) during the study period, and 16 of the 20 patients with chronic hypersensitivity pneumonitis had histopathological features on surgical lung biopsy that were consistent with this diagnosis. 26 of the 46 patients remained with a diagnosis of IPF.

INTERPRETATION

Almost half of patients diagnosed with IPF on the basis of 2011 criteria were subsequently diagnosed with chronic hypersensitivity pneumonitis, and most of these cases were attributed to exposure of occult avian antigens from commonly used feather bedding. Our results reflect findings in one centre with recognised expertise in chronic hypersensitivity pneumonitis, and further research and studies at other centres are warranted.

FUNDING

Fondo de Investigaciones Sanitarias; Fundació Privada Cellex; SEPAR 2010.

Management of hypersensivity pneumonitis

Hypersensitivity pneumonitis (HP) is an interstitial lung disease due to a combined type III and IV reaction with a granulomatous inflammation, caused by cytotoxic delayed hypersensitivity lymphocytes, in a Th1/Th17 milieu, chaperoned by a deficient suppressor function of T regulatory cells. Skewing toward a Th2 phenotype is reported for chronic HP. Phenotypic expression and severity depends on environmental and/or host genetic and immune co-factors. The wide spectrum of causative antigens is continuously up-dated with new sources of airborne organic particles and drug-induced HP. The diagnosis requires a detailed history, measurement of environmental exposure, pulmonary function tests, imaging, detection of serum specific antibodies, broncho-alveolar lavage, antigen-induced lymphocyte proliferation, environmental or laboratory-controlled inhalation challenge and lung biopsy. Complete antigen avoidance is the best therapeutic measure, although very difficult to achieve in some cases. Systemic steroids are of value for subacute and chronic forms of HP, but do not influence long term outcome. Manipulation of the immune response in HP holds future promise.

Detection of indoor and outdoor avian antigen in management of bird-related hypersensitivity pneumonitis

BACKGROUND

In the management of hypersensitivity pneumonitis (HP), antigen avoidance is crucial to prevent the progression of disease. Indirect and unrecognized exposure to the antigen may continue for a long time if persistence of the causative antigen is not recognized. To make a correct assessment of the patients' environment, we tried to establish the methods to detect indoor and outdoor avian antigens.

METHODS

Sixteen patients with bird-related HP, 4 asymptomatic breeders, and 6 healthy controls were examined. We prepared anti-pigeon dropping extracts (PDE) polyclonal antibody from rabbits. Air samples and house dust samples were analyzed by an antigen-capture ELISA with signal amplification using catalyzed reporter deposition.

RESULTS

In air samples, avian antigen could be detected in patients with HP (0.73 +/- 0.53 ng/m3) and asymptomatic breeders (0.63 +/- 0.23 ng/m3). In house dust samples, the amount of avian antigen was higher in patients with HP (2.4 +/- 1.8 microg/g) and asymptomatic breeders (4.1 +/- 2.3 microg/g) than in the controls (0.1 +/- 0.2 microg/g).

CONCLUSIONS

Detection of indoor and outdoor avian antigen might contribute to the correct diagnosis and appropriate managements of bird-related HP.

Potential contribution of fungal infection and colonization to the development of allergy

Fungi have long been recognized as an important source of allergens in patients with atopic disease. In this review, we explore the hypothesis that fungal exposures resulting in colonization or infection directly influence the tendency of an individual to develop allergic disease. According to this hypothesis, fungal exposures especially those early in life may influence the manner in which the immune response handles subsequent responses to antigen exposures. Studies detailing this potential connection between fungi have already provided important insights into the immunology of fungal-human interactions and offer the potential to provide new approaches and targets for the therapy of allergic disease. The first half of this review summarizes the data concerning fungal infections and asthma, including possible connections between fungal infections and urban asthma. The second half explores the potential role of the fungal gastrointestinal microbiota in promoting allergic inflammation.

Bird fancier's lung: a series of 86 patients

Bird fancier's lung (BFL) is one of the most common types of hypersensitivity pneumonitis. Nevertheless, the criteria for diagnosing this condition are not standardized. The current study is an in-depth investigation into the clinical characteristics of BFL in the largest series examined for this purpose by a single group, to our knowledge, taking into account the acute, subacute, or chronic clinical presentation. From 1977 to 2003, BFL was diagnosed in 86 patients using a homogeneous protocol. Data from the clinical history and physical examination were analyzed, as well as the results from the following complementary examinations: laboratory analyses, specific serum IgG antibodies determination, chest X-ray, chest computed tomography (CT), pulmonary function testing, immediate hypersensitivity skin testing, delayed cutaneous hypersensitivity testing, bronchofibroscopy with bronchoalveolar lavage (BAL) and/or transbronchial biopsy, bronchial challenge testing, and surgical lung biopsy. In addition, clinical and epidemiologic characteristics were determined in a control group of 60 pigeon breeders who did not meet the diagnostic criteria of BFL. Eighty-six patients (21 men and 65 women) with a mean age of 47 years were studied. Seven (8%) patients were younger than 15 years of age at the time of the diagnosis. In 3 cases, the disease was caused by exposure to feather-filled bedding. Nearly 1 in 5 patients was diagnosed in the chronic phase of the disease. The mean diagnostic delay was 1.6 years overall, and 3.2 years in patients diagnosed in the chronic phase of the disease. Among the 17% of patients with chronic disease, the mean interval from initiation of exposure to diagnosis was 16 years, a higher value than in the acute or subacute presentation forms. Dyspnea and cough were the most common clinical symptoms (98% and 82%, respectively), and nearly 25% had grade III or IV dyspnea at diagnosis. Only 18% of patients experienced chest tightness, a symptom classically considered to be frequent in this condition. Erythrocyte sedimentation rate was elevated (>30 mm/h) in 44% of patients. Urinary calcium was elevated in 20% of patients. Angiotensin-converting enzyme was not elevated in any of the patients in which it was measured. Lactate dehydrogenase increases were found in 51% of patients. Specific IgG antibodies to avian antigens were documented in 92% of BFL patients, but also in 87% of pigeon breeder controls. The most frequent radiologic finding was an interstitial pattern in 79% of patients. Common chest CT features were ground glass areas (68%) and a mosaic pattern (61%); areas of emphysema were found in 7/41 (17%) patients, 5 of whom had never smoked. Two patients had a CT pattern of pulmonary fibrosis indistinguishable from idiopathic pulmonary fibrosis. Immediate hypersensitivity skin testing with bird sera and pigeon bloom was positive in 78% and 100% of BFL patients, respectively, and in 64% and 88% of control pigeon breeders, respectively. Almost one-third of the patients (29%) presented an anergic response on delayed cutaneous hypersensitivity testing. Restrictive ventilatory impairment was the most frequent functional pattern (77%), although 9% and 4% showed a pure obstructive and mixed pattern, respectively. The carbon monoxide diffusing capacity was decreased (<80% of the predicted value) in 85% of cases. Forty-one percent of patients had PaO2 <60 mm Hg at diagnosis when blood gas analysis was performed. Lymphocytosis (>20% lymphocytes) was documented in 83% of patients who underwent BAL, with a similar frequency in the 3 presentation forms: 70% acute, 89% subacute, and 85% chronic. In addition, inversion of the CD4/CD8 ratio (<1) was observed in 62% of the patients, but 38% of cases showed a CD4 predominance. The characteristic triad of histopathologic findings in hypersensitivity pneumonitis was found in only 9% of patients undergoing transbronchial biopsy, but at least 1 of these findings was seen in 69%. Surgical lung biopsy was undertaken in 14/86 (16%) patients; the complete triad was observed in 50% and at least 1 finding in 100%. In 54/86 (63%) patients, the diagnosis was confirmed by bronchial challenge testing, a test with a sensitivity of 92% and specificity of 100%. BFL is a potentially severe disease that can progress to respiratory failure secondary to pulmonary fibrosis or chronic obstructive pulmonary disease, as a form of chronic occupational respiratory disease. Respiratory symptoms in exposed patients, including children and adults who have only 1 pet bird at home, should raise the suspicion of BFL. Diagnosis in the chronic phase is frequent, and the delay to diagnosis was greatest in these cases. Elevated urinary calcium, lactate dehydrogenase, and erythrocyte sedimentation rate in a bird fancier may constitute a combined marker for suspected BFL. Chest CT frequently discloses emphysema and a pattern of idiopathic pulmonary fibrosis in some patients. An anergic response on delayed cutaneous hypersensitivity testing is not infrequent. The presentation with respiratory failure and the predominance of CD4 T lymphocytes in some patients' BAL are both remarkable. Lymphocytosis on BAL also persists in the chronic phase of the disease. Bronchial challenge testing has a high diagnostic yield, and surgical lung biopsy is not needed to reach the final diagnosis in the vast majority of cases.

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.