Screening and diagnosis of acute and chronic bird-related hypersensitivity pneumonitis by serum IgG and IgA antibodies to bird antigens with ImmunoCAP®.

BACKGROUND: Bird antigens are some of the most relevant antigens in hypersensitivity pneumonitis (HP). Possible sources of bird antigens are bird breeding, feather products and fertilizer with fowl droppings. For the screening and diagnosis of HP, the measurement of bird-specific antibodies should be standardized. The aim of this study was to clarify the utility of serum IgG (sIgG) and IgA (sIgA) antibodies to bird antigens in screening and diagnosing acute/chronic bird-related HP with ImmunoCAP® in multi-centre clinical research. METHODS: We executed a clinical performance test by conducting a multi-institutional study to measure the levels of sIgG/sIgA against pigeon, parrot and budgerigar antigens by the ImmunoCAP® system in 29 acute and 46 chronic bird-related HP patients. RESULTS: The levels of sIgG/sIgA against the bird antigens of the three species were significantly higher in subjects with acute bird-related HP and chronic bird-related HP with acute episodes (recurrent type) than in the control subjects. For sIgG, the optimal cutoff values by receiver operating characteristic (ROC) analysis were 24.6 mgA/L for pigeon, 14.0 mgA/L for parrot, and 8.7 mgA/L for budgerigar. By measuring multiple bird antigens and combining sIgG values of two species, the sensitivity and specificity for acute and recurrent-type chronic bird-related HP patients were 85-91% and 73-80%, respectively. For recurrent and insidious types of chronic bird-related HP, the sensitivity and specificity were 48-61% and 73-80%, respectively. CONCLUSIONS: Measurement of the levels of sIgG/sIgA against pigeon, budgerigar and parrot antigens by ImmunoCAP® was useful for screening and diagnosis in bird-related HP.

Do glucocorticoids or carotenoids mediate plumage coloration in parrots? An experiment in Platycercus elegans.

Conspicuous coloration can indicate phenotypic quality, and may reflect exposure or vulnerability to stress, or access to essential nutrients such as pigments. Although the production of pigmented colours is well understood, much less is known about how structural colours are affected by physiological state. In this study, we tested whether glucocorticoids (corticosterone) predicted expression of plumage coloration in an Australian parrot, the crimson rosella (Platycercus elegans). Parrots provide an interesting and unique test, as they possess conspicuous coloration produced by distinctive pigments known as psittacofulvins, in addition to structural coloration. We have previously documented that coloration in P. elegans is condition-dependent and responds to dietary manipulation. Here, n = 21 P. elegans underwent a dietary manipulation (including food restriction or carotenoid supplementation) during which they moulted, and the change in reflectance was measured for three structural and three pigmentary plumage patches. Stress-induced corticosterone (10 min after handling) measured at the start of the experiment predicted change in coloration in two pigmentary patches (crown and front). We also found that change in stress-induced corticosterone during the experiment was associated with the change in coloration of the crown and two structural patches (cheek and epaulette). Baseline corticosterone (<3 min after handling) was not associated with any measure of coloration. We found no effects of dietary manipulation on baseline or stress-induced corticosterone, but carotenoid supplementation was associated with an increase in a measure of chronic stress (heterophil/lymphocyte ratio), and the corticosterone response to handling decreased over the course of the study. Our results suggest that corticosterone may be linked to colour expression more broadly than previously recognised, including psittacofulvin and structural coloration in parrots, and they confirm the independence of plumage pigmentation in parrots from carotenoid accumulation. Moreover, our study provides new insight into the stress responses of Psittaciformes, one of the most highly threatened avian orders.

Changes in PH in exhaled breath condensate after specific bronchial challenge test in patients with chronic hypersensitivity pneumonitis: a prospective study.

BACKGROUND: The aim of this study was to investigate the influence of the specific inhalation challenge (SIC) on changes of pH values in exhaled breath condensate (EBC) in patients with hypersensitivity pneumonitis (HP). METHODS: A prospective study of 85 patients with suspected HP, of whom 63 were diagnosed with HP due to exposure to avian or fungal antigens. In all cases, EBC samples were collected before and after completion of the SIC and pH values were determined. RESULTS: Taken as a whole, patients with HP did not present changes in EBC pH after SIC. However, considering only patients with exposure to molds, those diagnosed with HP had a significantly more acid pH post-SIC than those with another diagnosis (p = 0.011). This fact is not observed in patients exposed to bird's antigens. A ROC curve showed that a reduction in EBC pH of 0.3 units or more after SIC in patients diagnosed with HP due to exposure to molds had a sensitivity of 30 % (CI: 12.8 to 54.3 %) and a specificity of 100 % (CI: 65.5 to 100 %). CONCLUSION: EBC pH may be useful in interpreting SIC results in patients with HP, especially in those patients exposed to molds. Further studies are now required to test the validity of these proposals.

Evidence for multiple MHC class II ß loci in New Zealand's critically endangered kakapo, Strigops habroptilus.

Immunologically important genes of the major histocompatibility complex (MHC) have been characterized in a number of avian species with the general finding of considerable variation in size and structural organization among organisms. A range of nonpasserines which represent early-diverging Neoave lineages have been described as having only one MHC class II ß locus potentially leading to the conclusion that this is the ancestral condition. Here, we examine the monotypic, early-diverging, critically endangered kakapo, Strigops habroptilus, for allelic variation at MHC class II ß exon 2, as part of species' recovery efforts. We found two to four confirmed sequence variants per individual indicating the presence of more than one MHC class II ß locus. Given the kakapo's basal evolutionary status, evidence for multiple MHC class II ß loci seems to counter the proposed mono-locus history of modern birds. However, MHC gene duplication, maintenance, and loss among and within bird species may confound avian relationships making it difficult to elucidate the ancestral state. This study adds essential data for disentangling the course of MHC structural evolution in birds.

Prevalence of IgY antibodies against Erysipelothrix rhusiopathiae in a critically endangered parrot (kakapo, Strigops habroptilus) and associated responses to vaccination.

An enzyme-linked immunosorbent assay (ELISA) was developed to estimate levels of IgY antibody against the bacterium Erysipelothrix rhusiopathiae in serum samples collected from the critically endangered kakapo (Strigops habroptilus, Psittaciformes, Aves) before and after vaccination against this bacterium. Relative IgY antibody titres in pre-vaccination serum samples (n = 71 individual kakapo) were normally distributed with the exception of four outliers which displayed low IgY levels. Notably all four low IgY samples were collected from fledglings 3 - 6 months old. Pre-vaccination serum samples from nine nestlings <3 months old, seven of which were hatched in incubators and had no contact with either adult kakapo or their natural environment (e.g. soil), were found to have relatively high IgY levels, suggesting transfer of maternal IgY molecules to fledglings via the yolk. IgY levels in pre-vaccination serum samples from seven kakapo aged 25 - 30 months were also relatively high, suggesting that most kakapo naturally acquire anti- E.rhusiopathiae IgYs within their first 2 years. There was no evidence that vaccination increased the kakapo population's mean anti-E.rhusiopathiae IgY levels. However, there was a significant negative relationship between an individual bird's pre-vaccination IgY level and any subsequent increase following vaccination, suggesting that vaccination may only raise the IgY levels of birds with relatively low pre-vaccination IgY levels. A statistical model of the relationship between 'death from erysipelas' and sex, age and transfer from one to island sanctuary to another found that only transfer was significantly associated with death from erysipelas.

Identification of antibodies against hydropericardium syndrome in wild birds.

1. Domestic fowl and free-living birds were examined for the presence or absence of antibodies against hydropericardium syndrome (HPS) using an indirect haemagglutination assay. 2. Two-hundred and eighty serum samples of commercial (45 broilers, 20 adult layers and 15 Fayoumi fowl) and wild birds, including 65 peafowl, 45 pigeons, 10 crows, 30 house sparrows, 10 doves, 15 ducks, 10 parrots and 15 guinea fowl, were collected and examined. 3. The percentage of HPS-positive serum samples was 80% in house crows, 78% in pigeons, 7% in house sparrows and 6% in peafowl. 4. The sera obtained from parrots, doves, ducks and guinea fowl were all negative. 5. This study suggests that crows and pigeons could be carriers of the HPS agent.

Immune investment is explained by sexual selection and pace-of-life, but not longevity in parrots (Psittaciformes).

Investment in current reproduction should come at the expense of traits promoting future reproduction, such as immunity and longevity. To date, comparative studies of pace-of-life traits have provided some support for this, with slower paced species having greater immune function. Another means of investment in current reproduction is through secondary sexual characters (SSC). Investment in SSC's is considered costly, both in terms of immunity and longevity, with greater costs being borne by species with more elaborate traits. Yet within species, females prefer more ornate males and those males are typically immunologically superior. Because of this, predictions about the relationship between immunity and SSC's across species are not clear. If traits are costly, brighter species should have reduced immune function, but the opposite is true if SSC's arise from selection for more immunocompetent individuals. My approach was to investigate immune investment in relation to SSC's, pace-of-life and longevity while considering potentially confounding ecological factors. To do so I assessed leukocyte counts from in a novel group, the Psittaciformes. Investment in SSC's best explained investment in immunity: species with brighter plumage had higher leukocyte counts and those with a greater degree of sexual dichromatism had fewer. Ecological variables and pace-of-life models tended to be poor predictors of immune investment. However, shorter incubation periods were associated with lower leukocyte counts supporting the notion that species with a fast pace-of-life invest less in immunity. These results suggest that investment in reproduction in terms of fast pace-of-life and sexual dichromatism results in reduced immunity; however, investment in plumage colour per se does not impose a cost on immunity across species.

Diagnosis of Avian bornavirus infection in psittaciformes by serum antibody detection and reverse transcription polymerase chain reaction assay using feather calami.

Avian bornavirus (ABV) is the causative agent of proventricular dilatation disease (PDD), a highly devastating and contagious disease of psittacines (parrots and parakeets), which has resulted in the death of many captive birds. Accurate diagnosis of bornavirus infection is therefore important for the identification and isolation of infected birds. The current study showed that nonvascular contour (chest) feather calami provide a ready and minimally invasive source of RNA for the detection of ABV by reverse transcription polymerase chain reaction (RT-PCR). Storage of the feathers at room temperature for at least a month did not affect the results. Serological analysis by enzyme-linked immunosorbent assay (ELISA) showed that identification of anti-bornaviral nucleoprotein P40 antibodies can identify many birds with a past or present infection. The presence of anti-avian bornaviral P24 phosphoprotein and P16 matrix protein antibodies was quite variable, rendering these antibodies less useful for diagnosis of ABV infection. The significance of the present findings is that the use of nonvascular feathers as a source of RNA allows sample collection under conditions where storage of other samples would be difficult. Serum detection by ELISA of anti-P40 antibodies allows the identification of infected birds when RT-PCR fails.

Antigen-specific IgG antibodies in feather duvet lung.

BACKGROUND: Feather duvet lung (FDL) is a rare subgroup of bird fancier's lung (BFL). We were interested in determining antigen-specific IgG antibodies in patients with FDL and comparing them with those with BFL. MATERIAL AND METHODS: Specific IgG antibodies against goose and duck feathers, analysed with an automated fluorimetric enzyme immunoassay, were measured in healthy subjects (group A, n = 30), in patients with FDL (group B, n = 10) and with BFL (group C, n = 35); typical specific IgG antibodies of BFL in groups B and C. RESULTS: An optimal threshold value for antibodies against goose or duck feathers to differentiate patients with either BFL or FDL from healthy subjects was determined at 10.85 mg L(-1) for goose feathers and at 8.81 mg L(-1) for duck feathers, respectively. Specific IgG antibodies against goose feathers were significantly higher in group B compared with group C. A ratio of specific IgG antibodies against goose feathers and budgerigar antigens with a threshold value of 0.91 could discriminate between patients with FDL and BFL with a specificity of 97% and a sensitivity of 90%. CONCLUSIONS: We were able to demonstrate the significant difference in IgG antibodies in patients with FDL and BFL and their contribution to discriminate between these similar kinds of extrinsic allergic alveolitis.

Do leucocytes reflect condition in nestling burrowing parrots Cyanoliseus patagonus in the wild?

The different leucocyte types are an important part of the immune system. Thus, they have been used in ecological studies to assess immune function and physiological stress in wild birds. It is generally assumed that increased stress and decreased condition are associated with an increase in the ratio of heterophils to lymphocytes, the H/L ratio. We studied leucocyte profiles in relation to body condition in nestling Burrowing Parrots (Cyanoliseus patagonus) in North-eastern Patagonia, Argentina. As in other wild parrots, heterophils were the most numerous leucocyte type, suggesting strong investment into innate immunity. Leucocyte profiles did not change with the age, while nestlings in better body condition increased the number of heterophils. Because the number of lymphocytes was independent of body condition, as a result we observed a positive correlation between body condition and the H/L ratio. The total number of leucocytes relative to erythrocytes increased in nestlings in better body condition, indicating a larger overall investment into immune function in well-nourished nestlings. The observed heterophilic profiles of nestling Burrowing Parrots together with the positive relationship between H/L ratio and body condition may indicate a favoured investment in a robust innate immunity that reduces the risk of infection taking hold in these long-lived birds.

Production of a rabbit anti-cockatiel immunoglobulin G and characterization of its cross-reactivities with immunoglobulin G of other psittacine species.

The purpose of this work was to produce rabbit anti-cockatiel immunoglobulin G (IgG) and compare its cross-reactivity with sera from eight other psittacine birds: Quaker parakeet, budgerigar, green-wing macaw, blue-fronted Amazon parrot, eclectus parrot, African grey parrot, Patagonian conure, Moluccan cockatoo. Cockatiel IgG did not bind to protein A or G; therefore, these proteins could not be used in column chromatography to isolate the IgG. A combination of serum IgG precipitation by ammonium sulfate and yolk IgG extraction from egg was loaded in sodium dodecyl sulfate-polyacrylamide gel upon which the IgG was resolved by electrophoresis. The resolved IgG in sodium dodecyl sulfate-polyacrylamide gel was stained with Coomassie blue, cut, crushed in phosphate-buffered saline, and injected into rabbits. The rabbit anti-cockatiel IgG produced in this way reacted with a single protein in gel immunodiffusion assay with all nine psittacine bird sera but not with those of chicken and ostrich. Immunoelectrophoresis confirmed the cross-reactivity of different psittacine sera with the anti-cockatiel IgG serum but not with ostrich and chicken sera. This antiserum detected antibody responses in sera from cockatiels vaccinated against chlamydial major outer membrane protein in an immunoblot assay.

Feather mites are potentially an important source of allergens for pigeon and budgerigar keepers.

BACKGROUND: Previous studies on allergy to feathers have not addressed whether organisms living on feathers (mites, lice, moulds) are a source of allergens. OBJECTIVE: To investigate whether feather mites produced allergens of clinical relevance to bird keepers. METHODS: We examined serum IgE responses of 96 pigeon breeders to an extract of feather mites from pigeons (predominantly Diplaegidia columbae), using Western blotting, specific IgE assay using AlaSTAT EIA and RAST inhibition. RESULTS: Feather mites are a major source of soluble proteins derived from feathers, accounting for up to 10% of the total weight of the feather. Forty-three sera had a negative score (0) for anti-feather mite IgE, 27 were weakly positive (1-2) and 26 had strongly positive scores (3-4). Fewer pigeon breeders with scores > or = 3 were asymptomatic than those with negative scores (12 versus 40%), more had late onset symptoms (with or without early onset symptoms: 77% versus 44%) and had IgE antibody against house dust mite (89% versus 23%). Western blotting of eight sera against the extract of Diplaegidia columbae revealed 20 IgE-binding components ranging from 22 to 200 kDa. A high diversity of components was recognized by each serum: arithmetic mean 7 (range 2-14). RAST inhibition indicated feather mites had species-specific epitopes as well as ones that cross-reacted with Dermatophagoides pteronyssinus. CONCLUSION: Strongly-positive AlaSTAT scores to pigeon feather mite were associated with allergic symptoms of late onset in pigeon breeders. We conclude that feather mites are a major source of clinically-relevant allergens for pigeon breeders.

Failure of maternally derived yolk IgG to reach detectable concentrations in the sera of nestling budgerigars (Melopsittacus undulatus).

Transfer of maternal immunoglobulin G (IgG) to the yolk and nestling was investigated in the budgerigar. Specific antibodies to avian polyomavirus and Newcastle disease virus could be detected in 82% of yolk extracts of eggs from seropositive hens. Using a double immunodiffusion assay with anti-chicken IgG antibodies, IgG could also be detected in yolk supernatants with virus neutralizing activity. In all assays, IgG concentrations in the yolk extracts were significantly less than those of the adult budgerigar serum. No antiviral activity was detected in nestling serum. Examination of nestling serum with the double immunodiffusion assay and an immuno-dot-blot technique specific for IgG showed that detectable concentrations of IgG are not present in nestling serum until after the yolk sac is fully absorbed. This observation, coupled with the absence of specific anti-viral antibody in nestlings of seropositive hens, indicated that none of the yolk sac antibody reached the nestling circulation.

Elementary body agglutination for rapidly demonstrating chlamydial agglutinins in avian serum with emphasis on testing cockatiels.

The development and use of a stained chlamydial elementary body agglutination (EBA) antigen for detecting antibody activity in avian sera is described. Examples of serologic results on serum samples from various types of birds indicate the usefulness of EBA, latex agglutination (LA), and direct complement fixation (DCF) in diagnosing avian chlamydiosis. Results of tests on 10 cockatiels examined in clinics indicate that a combination of serology, culture, and/or antigen-detection enzyme-linked immunosorbent assay may be helpful when testing this type of bird. Agreement between EBA, LA, and DCF was 81.8% when testing 407 serum samples from cockatiels of unknown health status. The relationship between positive (> or = 10 titer) antibody activity and known health status of 77 cockatiels revealed that agreement between the two criteria was only 59.7%. Of 13 Chlamydia-inoculated cockatiels, seven birds seroconverted from negative to positive by EBA; five seroconverted by DCF. Only the five birds that seroconverted by both EBA and DCF were culture-positive for chlamydiae. None of 15 sham-inoculated control cockatiels developed detectable antibody activity, and none of 10 cultured were positive. In tests with column-separated IgM and IgG, EBA detected only IgM activity, LA detected IgM and IgG activity, and DCF detected only IgG activity.

Parrot breeder's lung: first case report in China.

The authors report the first case of parrot breeder's lung in China and the study of its immunology, respiratory physiology, as well as pathology. The main characteristics of this disease are progressive dyspnea after contacting parrots, patchy or reticular shadows in the lower lung fields on chest X-ray, the presence of alveolitis, accompanied by pulmonary interstitial fibrosis as demonstrated in lung biopsy, restrictive or mixed ventilation disorders with reduction of diffusing capacity and lung compliance. The results of specific ring precipitation test and counter immunoelectrophoresis were helpful in diagnosis. The importance of early diagnosis and treatment is also discussed.

Nasal allergy to avian antigens.

This study describes the case of a patient who developed symptoms of rhinoconjunctivitis on exposure to budgerigars and parrots. An IgE-mediated allergy to budgerigar, parrot and pigeon antigens was demonstrated using both in-vivo challenge tests (skin and nasal provocation tests) and in-vitro investigations (radio-allergo-sorbent test, histamine release test). The study shows that the development of nasal disease can be associated with allergy to avian antigens.