Down regulation in hypersensitivity pneumonitis

Levels of soluble interleukin-2 receptor (sol-IL-2R) in the bronchoalveolar lavage fluid (BALF) of pigeon breeders with hypersensitivity pneumonitis were compared with BALF levels in asymptomatic pigeon breeders who had been exposed to pigeon allergens for an equivalent length of time. No mean difference in sol-IL-2R levels was detected when these levels were expressed per milliliter BALF, epithelial lining fluid, or per T-lymphocyte. In sarcoidosis, the availability of sol-IL-2R per T cell was significantly higher for the group with inactive sarcoidosis compared with the group with active sarcoidosis. The results do not support the hypothesis that down regulation, in subjects exposed to allergens causing hypersensitivity pneumonitis, is a function of cell-free sol-IL-2R levels in BALF. In the dynamic situation, however, the hypothesis appears tenable.

[Diagnostic aspects of allergic alveolitis]

The clinical picture of extrinsic allergic alveolitis (EAA) or hypersensitivity pneumonitis is etiologically extremely multivarious and in disposed persons it can be caused by inhalation of proteins of various species of animals (in particular by avian proteins), mushrooms, bacteria, insects, thermoactinomycetes, vegetable antigens, possibly also haptens after fixation with protein produced inside the body. The inhaled dusts with a size particles of 4 to 5 micrometers which contain the disease-evoking antigens often have an activity-specific character which is expressed in the traditional names of individual forms of alveolitis (e.g. farmer's lung, mushroom-worker's lung, cheese-washer's lung, malt-worker's lung, bagassosis). However, according to our inquiries in the GDR as well as in other parts of Central and East Europe these diseases are relatively rare. In the GDR the so-called bird-fanciers' or bird-keepers' lung with a frequency of 83.4% has a supreme significance within all forms of alveolitis, followed by the farmer's lung (8.9%) and forms of alveolitis by mushrooms (7.7%). In a period of 10 years altogether 7,669 sera of patients with suspicion of alveolitis were investigated at our institute. According to the results of the immunological as well as of further paraclinical and clinical examinations in 550 cases the diagnosis of allergic alveolitis was made (459 bird-fancier's lungs, 49 farmer's lungs and 42 cases of allergic alveolitis by moulds). In 88.5% of the patients who fell ill with extrinsic allergic alveolitis the disease is accompanied by a positive or very positive antigen-specific antibody formation in the blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Enzyme immunoassay for pigeon breeders' disease without the use of extraneous antibody

A rapid enzyme immunoassay technique is described for the detection in human sera of antibodies of any class to pigeon antigens. The method is based on binding human antibodies in excess to polystyrene-fixed antigens from pigeon droppings or pigeon serum, followed by capture of the same antigens coupled to peroxidase. A very good correlation was found of titers obtained by means of this 60-min assay with traditional sandwich immunoassay and with precipitation- and complement - fixation tests.

Precipitating antibodies against pigeon bloom antigens as a specific and sensitive measure of pigeon exposure

Precipitating antibodies against pigeon bloom antigen and pigeon serum were evaluated as a measure of pigeon exposure in 62 male pigeon breeders compared with 40 unexposed control subjects. We found a combination of highly antigenic bloom extract and a sensitive counter current immunoelectrophoresis suitable for clinical estimation of pigeon exposure. The sensitivity of the test was 86% in never-smokers and 73% in smokers at the 98% specificity level. Smoking significantly reduced the humoral immune response to both antigens.

[Two cases of budgerigar breeder's lung]

We report 2 patients with Bird breeder's lung associated with keeping budgerigars. Patient 1 kept a budgerigar indoors for 13 years. Histological examination revealed fibrosis and granulomatous changes in the alveolar septa. Among T lymphocyte subsets in BALF, helper T cell were increased. In the serum, precipitating antibodies to budgerigar dropping extract were observed. Patient 2 had kept Budgerigar for 7 months. Histologically, alveolitis was the primary finding, and suppressor T cell in the BALF were increased. Precipitating antibodies to budgerigar dropping extract was observed only in the BALF but not in serum. In patient 1 who showed a chronic course and granuloma formation, helper T cell in the BALF were increased while in patient 2 who showed an acute course and alveolitis, suppressor T cell in the BALF were increased, and precipitating antibody was observed only in the BALF. These findings suggest that T lymphocyte subsets in the BALF differ depending on the stage of hypersensitivity pneumonitis, and specific local antibody production precedes systemic antibody production.

Clinical and serologic follow-up of four children and five adults with bird-fancier's lung

We report the clinical and serologic findings in four children and five adults with chronic avian hypersensitivity pneumonitis. All subjects were treated with corticosteroids and bird exposure was reduced or eliminated. After a variable period, ranging from 6 months to 10 years, their clinical and serologic findings were reassessed. In terms of symptomatology, chest findings, and pulmonary functions, all four children improved and four adults improved, whereas one adult had a progressive clinical deterioration, ultimately resulting in her death 5 years later. In terms of serologic data, precipitating antibody tended to persist, and antibody to avian antigens, as determined by ELISA, remained positive, although the titer declined. We conclude that, while serologic positivity remains, the prognosis for children and adults with chronic avian hypersensitivity pneumonitis is very good, provided that irreversible damage has not already occurred at the time of diagnosis.

[A case of pigeon breeder's disease]

A 73-year-old woman developed dry cough and exertional dyspnea. She had been breeding pigeons for thirty years. Her serum showed positive precipitin reaction against pigeon serum. Furthermore the lymphocyte stimulation test against pigeon serum was positive. An X-ray film of the chest showed diffuse ground glass infiltrate, fine nodular shadows and reticular shadows. Histopathology revealed diffuse interstitial infiltration with mononuclear cells and occasional giant cell formation as well as granuloma formation in the bronchiole. The symptoms subsided after admission. From these results, this case was diagnosed as pigeon breeder's disease. She had the subacute form probably because of her old age and smoking. It could be that exacerbation of pneumonitis was caused by cessation of smoking in an attempt to alleviate the symptoms. This is the fifth case reported in Japan.

Detection of antibodies against avian antigens in bronchoalveolar lavage from patients with pigeon breeder's disease: usefulness of enzyme-linked immunosorbent assay and enzyme immunotransfer blotting

The study reported here evaluated the usefulness of the enzyme-linked immunosorbent assay (ELISA) in the detection of antibodies against pigeon antigens in the serum and bronchoalveolar lavage (BAL) of patients with clinical, radiological, and functional evidence of interstitial lung disease (ILD) with and without pigeon breeder's disease (PBD). The results were compared with those obtained by the simultaneous use of counterimmunoelectrophoresis (CIE) in the same patients. In PBD, ELISA detected antibodies against pigeon's sera in both serum and BAL in 100% of patients, while CIE failed to detect the antibodies in the serum of one patient and in most of the samples of BAL. In addition, we used enzyme immunotransfer blotting to determine the number of epitopes in pigeon serum recognized by antibodies present in serum and BAL. There was a heterogeneous response in both fluids, but the reaction pattern demonstrated that patient's sera recognize to-25 different pigeon epitopes. We conclude that ELISA is a highly sensitive and specific method for the detection of antibodies against pigeon antigens in the serum and BAL of patients with PBD and that the host response involves a great number of avian antigens.

Identification of a 'disease-associated' antigen in pigeon breeder's disease by western blotting

Sera from 9 symptomatic and 7 asymptomatic pigeon breeders were analyzed for their reactivity to pigeon serum by western blotting. All 9 symptomatic sera (9/9; 100%) and only 4 of 7 (57%) asymptomatic sera revealed specific antibodies. The immunoreactivity patterns of the sera varied: the majority of the sera reacted to antigens having molecular weights of 220 kD or more (9/16 sera), 98 kD (8/16 sera), and 86 kKD (8/16 sera). However, only sera from symptomatic breeders recognized an antigen of approximate molecular weight of 29-32 kD (9/9; 100% of symptomatics). We conclude that this antigen is 'disease associated' and may be useful in the diagnosis of pigeon breeder's disease.

[Allergic alveolitis among pigeon breeders in the county of Funen]

Two hundred pigeon breeders from the county of Funen were invited to participate in the study. No definite cases of allergic alveolitis were found among the 68 participants. 40% had experienced airway and/or general symptoms in connection with pigeon exposure. However, most of these symptoms could be explained as irritation of the airway and chronic bronchitis. Precipitating antibodies to pigeon serum and to an aqueous pigeon bloom extract were determined. The antibody titers did not differ in pigeon breeders with or without symptoms. Smokers had lower antibody titers to pigeon antigens and a lower level of total serum IgG, but reported symptoms in connection with pigeon exposure as often as non smokers.

Obstructive airways disease in non-smoking subjects with pigeon fanciers' lung

The aim of the study was to assess the degree of airways involvement in non-smoking subjects with extrinsic allergic alveolitis resulting from pigeon-derived antigens. Two hundred and eight pigeon fanciers completed a questionnaire of symptoms, performed spirometry on a Vitalograph Compact spirometer and had IgG antibody to pigeon gamma-globulin measured. Eighty fanciers had the acute form of pigeon fanciers' lung (PFL) and these subjects were less likely to be current smokers (P less than 0.001). Subjects with PFL had a higher prevalence of chronic bronchitis (P less than 0.001), large airways (P = 0.014) and peripheral airways obstruction (P less than 0.001). The prevalence of chronic bronchitis and peripheral airways obstruction increased significantly as the level of antibody to pigeon gamma-globulin rose. Peripheral airways obstruction, as manifest by a reduced FEF25-75%, was the most common abnormality found. Airways disease is an important feature of the acute form of PFL and consists of a hypersecretory disorder in the form of chronic bronchitis and of obstructive airways disease particularly affecting the peripheral airways.

Immunoregulatory proteins in bronchoalveolar lavage fluid. A comparative analysis of pigeon breeders' disease, sarcoidosis and idiopathic pulmonary fibrosis

Bronchoalveolar lavage fluid (BALF) cell profiles, interleukins 1 and 2, (IL-1 and IL-2) and soluble interleukin 2 receptor (IL-2R) levels from patients with pigeon breeders' disease (PBD) (n = 24) and asymptomatic pigeon breeders (n = 10) were compared with those from patients with active sarcoidosis (n = 11), inactive sarcoidosis (n = 10), idiopathic pulmonary fibrosis (n = 25) and normal subjects (n = 10). BALF total cells, lymphocytes and OKT4 receptor-bearing lymphocytes/ml were higher in PBD and active sarcoidosis compared with normals (P less than 0.02 all comparisons). In the asymptomatic pigeon breeders bronchoalveolar (BA) lymphocyte numbers/ml were higher than controls (P less than 0.01) producing a subclinical lymphocytic "alveolitis" in 80% of subjects, although compared with symptomatics, % OKT4 (helper) cell numbers were lower (P less than 0.05). OKT4/OKT8 ratios in both groups were normal, whereas in active sarcoidosis ratios were higher (P less than 0.05) but with considerable overlap. Mean levels of IL-1 and IL-2 were raised in the BALF from all groups compared with normals (P less than 0.01 all comparisons), IL-2 being higher in active sarcoidosis and IPF compared with PBD (P less than 0.01). There was no significant difference in detectable BALF soluble IL-2R between patient groups, although its levels correlated positively with IL-1 (22 paired samples from all groups (rs = 0.8, P less than 0.02) and negatively with % and T-lymphocytes/ml in PBD (rs = 0.75, P less than 0.02, rs less than 0.8, P less than 0.01). However, when BALF soluble IL-2R is expressed in terms of T lymphocytes/ml of epithelial lining fluid (ELF), asymptomatic pigeon breeders had significantly higher levels than their symptomatic counterparts (P less than 0.01). It is concluded that percentage lymphocytes [corrected] are similar in both groups of pigeon breeders, although those with PBD had increased numbers of OKT4 (helper) cells. Patients with active sarcoidosis could not be reliably differentiated from those with acute PBD on the basis of BAL cell profiles. Our results suggest that IL-1 leads to soluble IL-2R formation and that continued antigenic stimulation, as with inhaled pigeon allergens, results in a down regulation of BALF IL-2. Excess BALF soluble IL-2R on a cellular basis suggests a mechanism by which some pigeon breeders remain asymptomatic.

Longitudinal course of extrinsic allergic alveolitis in pigeon breeders

The purpose of this study was to assess the longitudinal course of pigeon breeders' disease by evaluating 24 patients with the acute form of the disease 10 years after their original diagnosis. Twenty one patients attended for clinical assessment, pulmonary function studies, chest radiography, and antibody measurement. Eighteen had continued to keep pigeons, emphasising their commitment to the hobby. Despite continued antigen exposure pigeon related symptoms had improved in most patients and only five still had troublesome symptoms. Four patients had residual abnormalities of pulmonary function or chest radiographs and three had chronic bronchitis. Fanciers had attempted to regulate their exposure to the birds by use of masks and by spending less time in their lofts but this is an unlikely explanation for the benign course of their disease, as levels of antibody to pigeon gammaglobulin remained high, suggesting that appreciable antigen exposure was still occurring. In most cases a state of equilibrium between host and antigen appeared to have developed. This observation has implications for the clinical management and understanding of the nature of the disease.

Cell-mediated immunity in pigeon breeders' lung: the effect of removal from antigen exposure

Eighteen precipitin-positive pigeon breeders, thirteen symptomatic (SPB), with extrinsic allergic alveolitis (EAA), and five asymptomatic (APB), without lung disease, underwent bronchoalveolar lavage (BAL). Cytospins were prepared on which differential cell counts were performed. Immunocytological methods, using monoclonal antibodies, were performed to identify lymphocyte and macrophage subsets. Marked abnormalities in cell populations were observed in both groups but with no suggestion of differences between the groups. All subjects had a lymphocytosis in BAL (SPB 45%; APB 29%). These lymphocytes were almost exclusively T-cells. The cluster designation CD4/CD8 ratio was decreased (SPB 0.86; APB 1.13) and a significantly higher proportion of these cells than normal expressed UCHL1 (an antigen associated with the common leucocyte antigen complex) indicating immune commitment. In the macrophage population increased proportions of cells expressing antigens associated with interdigitating cells (RFD1+) and mature macrophages (RFD7+) were also abnormal. When six SPB patients were relavaged after isolation from pigeons for three weeks, there was a significant reduction in the lymphocytosis and in the proportion of UCHL1+ lymphocytes. This was accompanied by reductions in the percentage of macrophages expressing RFD1 and UCHL1. We suggest that EAA in pigeon breeders is associated with a cell-mediated immune response which is down-regulated by isolating patients from exposure to pigeon derived antigens.

Impaired non-specific delayed cutaneous hypersensitivity in bird fancier's lung

The relation between non-specific delayed cutaneous hypersensitivity and bird fancier's lung was investigated in 13 patients with the disorder. They were compared with 50 subjects who had no reason to have decreased non-specific delayed cutaneous hypersensitivity (control group) and 34 patients with pulmonary sarcoidosis. In addition, 13 patients with bird fancier's lung (11 of the original group) were tested at least one year after avoiding exposure to the causal antigen. Five antigens (candidine, staphylococcal toxoid, tuberculin purified protein derivative, trichophyton, and streptokinase-streptodornase) were injected intradermally (0.1 ml) and the mean weal diameter was measured at 48 hours. The mean weal size was significantly less in the subjects with bird fancier's lung at the time of diagnosis than in the control group (2.23 v 5.66 mm) but did not differ significantly from that of the subjects with sarcoidosis (2.80 mm) or from that of the bird fanciers with no exposure to the causal antigen for one year (2.75 mm). The impairment of non-specific delayed cutaneous hypersensitivity in patients with bird fancier's lung appears to be quantitatively similar to that occurring in sarcoidosis.

The long-term effect of a positive pressure respirator on the specific antibody response in pigeon breeders

A group of pigeon fanciers with Pigeon Breeder's Lung wore a positive pressure respirator with a full mask and hood when working with pigeons. Serial measurements of specific IgG antibody to pigeon globulin (ELISA) were made in 22 subjects. Thirteen wore a respirator (monitored over 14 months) and nine did not (monitored over 3 months). Following introduction of the respirator, the serum antibody to pigeon globulin significantly decreased when compared with the non-respirator group. This fall in antibody persisted over 14 months reflecting the reduction of antigen inhalation. Although circulating antibody decreased in all those wearing respirators, the remaining levels were still within the range that can be associated with clinical symptoms possibly because of inward leakage of antigen bypassing the filter.

Circulating autoantibodies in patients with pigeon breeder's disease

Sera from 19 patients with hypersensitivity pneumonitis induced by avian antigens were studied in order to determine the presence of circulating autoantibodies. IgM and IgG rheumatoid factors were positive in 68% and 100% of the cases respectively. IgM-rheumatoid factor was detected with at least two methods, showing titers between 1:20 and 1:1280 by the latex agglutination test and between 140 and 579 IU/ml by nephelometry test. The IgG rheumatoid factor was studied by the indirect immunofluorescence technique, showing positive determinations in all of our hypersensitivity pneumonitis patients. Titers of these autoantibodies ranged from 1:80 to 1:640. In addition, we studied the presence of antinuclear, anti-nDNA, anti-mitochondrial, and anti-smooth muscle antibodies by the immunofluorescence test using HEp-2 cells, mouse kidney, and Crithidia luciliae targets. Sera from all of our hypersensitivity pneumonitis patients have negative results of autoantibodies to these antigens. Negative results of autoantibodies to the nRNP, Sm, SS-A(Ro) and SS-B(La) nuclear antigens by counterimmuno-electrophoresis and double immunodiffusion techniques were also obtained. As controls we studied 14 healthy individuals and 8 subjects exposed to avian antigens but without hypersensitivity pneumonitis symptoms and no positive determinations for rheumatoid factor, antinuclear antibodies, as well as to anti-mitochondrial and anti-smooth muscle antibodies, were found. These findings support that different immune abnormalities are present in patients with hypersensitivity pneumonitis induced by avian antigens. One of these immune alterations or a combination of them may promote or facilitate the acute interstitial lung injury and/or perpetuate a chronic inflammatory process.

Pigeon breeder's disease: the effect of antigen-specific antibodies on in vitro T cell responses of normal blood lymphocytes

The effect(s) of affinity-purified antibodies to pigeon serum immunoglobulins on normal T cell responses in vitro was measured. Our results show that the antibodies partially inhibited the concanavalin-A-induced proliferation of normal lymphocytes (32% at 10 micrograms/ml concentration; p less than 0.001), whilst they had no significant effects at equivalent doses on the phytohemagglutinin-induced response. A study of the kinetics of this inhibition revealed that the antibodies exerted their effect(s) within the first 24 h of culture (p less than 0.001); this is probably due to their interference in early events intimately involved in the de novo synthesis and expression of activation antigens such as HLA-DR and Tac: antibody-treated cultures expressed 51.6 and 41.4% less HLA-DR and Tac, respectively. Two-colour immunofluorescence analysis showed that the specific antibodies bind to a subset of CD8+ cells only.

In vitro reactivities of blood lymphocytes from symptomatic and asymptomatic pigeon breeders to antigen and mitogens

The proliferation of blood lymphocytes in response to pigeon gammaglobulin in the presence or absence of IL2 was measured in 9 symptomatic and 12 asymptomatic pigeon breeders and 24 controls. The symptomatic breeders exhibited spontaneous lymphocyte proliferation (p less than 0.001) when compared with controls whilst lymphocytes from asymptomatic breeders required the simultaneous addition of IL2 in order to proliferate (p less than 0.001). IL2 alone did not induce cellular proliferation. Both patient groups had abnormal T-cell functions and response to lectins and, in the symptomatic group, there existed an inverse correlation (r = -0.70, p less than 0.001) between specific antibody titres to pigeon gammaglobulin and the Con A response. We conclude that both patient groups have circulating, presensitized antigen-specific lymphocytes but these require different stimulatory signals at the cellular level.

Effect of cigarette smoking on the specific antibody response in pigeon fanciers

Titres of circulating IgG antibodies to pigeon gammaglobulin and end expired carbon monoxide concentrations were measured in 86 pigeon fanciers attending the "Show of the Year." Antibody levels were significantly higher in non-smokers and in those with end expired carbon monoxide concentrations below 10 parts per million.

Immunochemical properties of the antigens involved in the pigeon breeder's disease

The pigeon breeder's disease is a form of extrinsic allergic alveolitis caused by the exposure to pigeon droppings. Chemical analysis of this antigen was carried out employing column fractionation techniques. Sephadex G-50 and DEAE cellulose were performed and several proteins and hexoses peaks were recorded. Molecular weights were determined by comparison with standardized marker proteins passed through a drop counting fraction collector. The whole extract revealed a molecular weight of 100 Kd while fraction 1 showed 66 Kd and fraction 2 only 30 Kd. A guinea pig experimental model was developed with the whole extract injected by the intradermal route, administered by an intragastric catheter or aerosolized in a glass chamber. Histopathological studies were carried out with the lungs, kidneys, liver and spleen obtained by the necropsy of the animals. The lungs and the kidneys showed the paramount changes in their structures with lymphomononuclear infiltrates and an Arthus-like phenomenon surrounding the vessels. Immunological techniques were applied to the sera and the lymphocytes obtained from the animals. Precipitin and hemagglutinating IgG antibodies were detected against the whole extract and the fractions obtained by column fractionation. Sensitized lymphocytes were also detected. This experimental model represents a guide in the approach to the human allergic alveolitis whose immunological findings will be presented in a forth-coming report.