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.

Pigeon fanciers' lung: effects of smoking on serum and salivary antibody responses to pigeon antigens

A reduced prevalence of pigeon fanciers' lung has been reported in pigeon breeders who smoke cigarettes. Serum and salivary antibodies to pigeon intestinal mucin and pigeon serum proteins were investigated in 227 pigeon fanciers, subdivided according to smoking habit and clinical status. Smokers had a lower incidence of precipitating antibodies to pigeon antigens and lower titres of serum IgG and IgA antibodies to mucin and to pigeon serum proteins in ELISA compared with non-smokers and ex-smokers. In contrast, IgG antibody titres to tetanus toxoid were similar in smoking and non-smoking groups. In contrast to serum antibodies, salivary IgA antibody titres to pigeon antigens were similar in smokers and non- or ex-smokers. Approximately one third of the smokers reported symptoms consistent with pigeon fanciers' lung but did not have precipitating antibodies. Only some individuals with precipitating antibodies had disease symptoms, and IgG antibody titres in these individuals were not significantly higher than in many asymptomatic individuals. Salivary IgA titres against pigeon mucin were significantly higher in asymptomatic individuals, consistent with a protective role for these antibodies. The results confirm that smoking is associated with a decreased serum antibody response to inhaled pigeon antigens, affecting IgG1, IgG2 and IgA responses, but this impairment does not extend to salivary IgA or to antibody responses to a parenterally administered protein antigen. The fact that responses to pigeon serum proteins and to pigeon intestinal mucin were similarly affected suggests that cigarette smoking depresses both T-independent and T-dependent responses to inhaled antigens.

[Sensitization in budgerigar owners]

In a prospective study 258 adults were investigated for sensitisation against bird antigens (budgerigar, canary, pigeon) using intracutaneous test. 18 of 78 budgerigar keepers were sensitised against budgerigar feathers. 30 (38%) showed a positive skin reaction at least with one of the three extracts tested. In none bird exposed persons a sensitisation was found in 18/96 (19%) against budgerigar and in 24/96 (25%) against at least one of the three allergen extracts. Late reactions occurred in 5/70 (7%) budgerigar keepers, 4/5 with pigeon feathers. The frequency of sensitisation against budgerigar antigens increased to 48% of bird keepers (24/50) if the birds could fly in their homes instead of being caged always (4/22, 18%). Three of the 78 budgerigar keepers (4%) had a positive nasal provocation with feathers extract, they were skin positive against all three bird antigens tested.

[Lung function in workers in a chicken slaughterhouse in the city of Maracaibo, Venezuela]

In order to evaluate the respiratory health status in workers exposed to antigenic substances (chicken feathers, serum and dropping), typical of usual practice in the avian slaughter-house, pulmonary function was studied on 49 exposed workers, and in a sample of 49 people with similar anthropometric characteristics, non exposed to these substances, by means of occupational-medical history, spirometric tests, hematologic and biochemical tests, and postero-anterior chest x-rays. The values for the spirometric parameters varied with sex, age, weight, size, smoking habits, length of employment and exposure time, and there were no significant differences between exposed and control groups as a whole; showing significant differences with decreasing values for CVF, VEF1, PFE, FEF-25% and FEF-50% in the intermediate zone workers, and in subjects with short exposure time (< 1 year). Prevalence of clinical findings in the exposed population was significantly higher than the non exposed group (p < 0.001). Laboratory tests showed reduction of monocytes cells in the exposed group (p < 0.05) in addition, in the exposed women there was an increase of the eosinophiles, total proteins and globulines (p < 0.05). The frequency of radiographic findings was significantly higher in the exposed group (p < 0.006), and they were no specific. The lack of association between clinical findings, laboratory and radiographic findings, with the spirometric results, could be explained by the short period of exposure, individual and collectives hygienic conditions and size of the sample.

[Extrinsic allergic alveolitis of occupational origin]

Occupational factors encountered in farming and other agricultural activities produce a particular risk for respiratory diseases. For some, such as extrinsic allergic alveolitis, diagnosis depends upon a range of epidemiological, clinical, radiological and immunological arguments. Farmer's lung is one of the most common form of extrinsic allergic alveolitis. Bird breeder's lung is another, the list is long. The environmental allergens likely to affect alveoli and interstitial tissues have been identified, but simple detection of antibodies does not constitute a pathognomonic criterion of extrinsic allergic alveolitis. Co-immuno-electrodiffusion is a rapid and sensitive technique for the demonstration of remarkable precipitating systems of extrinsic allergic alveolitis. This investigation enables subjects who really have the disease to be distinguished from contact subjects. Diagnosis is important to prevent development of a disabling and irreversible pulmonary fibrosis.

Relationships between characteristics of exposure to pigeon antigens. Clinical manifestations and humoral immune response

An extensive clinical study has been performed on pigeon breeders in the Canary Islands. Three hundred forty-three subjects have participated in this study through the filling of a clinical and epidemiologic questionnaire. A venous blood sample was also taken from each fancier for a further serologic analysis. Detection of specific IgG antibodies was made by an indirect enzyme-linked immunosorbent assay (ELISA) using pigeon serum as antigenic material. Twenty-nine (8 percent) breeders fulfilled the "classic" pigeon breeders' disease (PBD) criteria. One hundred six (31 percent) had rhinitis, 62 (19 percent) had immediate bronchial symptoms, and 51 (15 percent) suffered from chronic bronchitis. A significant level of specific IgG was detected in 139 (40 percent) cases. Rates were correlated with pneumonitis symptomatology (p < 0.001) and with chronic bronchitis (p < 0.05). There was a significant association between the number of pigeons and the level of sensitization (p < 0.001). Finally, a statistical relationship between the intensity of exposure and specific IgG response was also found (p < 0.001). Titers of specific IgE could not be related either to the reported symptomatology in the questionnaire or to any of the exposure parameters analyzed.

Elevated levels of bronchoalveolar lavage vitronectin in hypersensitivity pneumonitis

Vitronectin is an adhesive glycoprotein that is present in plasma and the extracellular matrix. Hypersensitivity pneumonitis (HP) is characterized by pulmonary inflammation and damage to the extracellular matrix. Perhaps reflecting this, fibronectin has been found to be elevated in the lower respiratory tract of subjects with HP. Vitronectin, like fibronectin, binds to both extracellular matrix components and cells and may mediate tissue remodeling. Thus, it was investigated whether vitronectin might be increased in bronchoalveolar lavage (BAL) fluid of patients with HP. Vitronectin and, for comparison, fibronectin were measured in BAL fluid from 16 patients with HP and nine healthy control subjects by enzyme-linked immunosorbent assay. Vitronectin was significantly increased in the HP group (658.4 +/- 121.8 ng/ml) compared with the controls (58.4 +/- 11.1 ng/ml, p < 0.001) and was found to be positively correlated with fibronectin. Patients whose last antigenic exposure was 4 or fewer days before the BAL had statistically significantly higher BAL vitronectin and fibronectin than did patients whose last exposure was 5 or more days before the BAL. The serum vitronectin levels did not differ. There was no significant relationship between the lavage fluid vitronectin and fibronectin levels and the BAL cell profile in HP. This study confirms that vitronectin, like fibronectin, is a normal constituent of the lower respiratory tract, and demonstrates that vitronectin is elevated in the lower respiratory tract of patients with HP and may play a role in tissue remodeling and fibrosis in this disease.

A comparison of the seroepidemiology of chlamydial infection in pigeon fanciers and farmers in the U.K

A detailed comparative seroepidemiological study of antibody responses was performed in 271 pigeon fanciers and 100 farmers. Overall 73% of pigeon fanciers had IgG antibodies at a titre greater than or equal to 16 to Chlamydia pneumoniae, 39% to Chlamydia psittaci, and 6.6% to Chlamydia trachomatis. The prevalence of chlamydial antibodies was significantly lower in the farmers at 47% for C. pneumoniae, 6% for C. psittaci, and 2% for C. trachomatis. Both populations were exposed to complex microbiological and antigenic environments: 50.5% of the pigeon fanciers had antibodies to pigeon antigens, 34% to egg membrane, and 0.73% to yolk sac antigen, and 59% of the farmers had antibodies to Micropolyspora faeni, but the high prevalence of chlamydial antibodies could not be attributed to interaction with these antigens. There was considerable overlap of chlamydial antibody responses in the pigeon fanciers but not in the farmers: 36% of the pigeon fanciers had antibodies to C. pneumoniae alone, 5% to C. psittaci alone, and 31% to both agents, whereas only 3% of farmers had antibodies to both C. pneumoniae and C. psittaci. The high prevalence of antibodies to C. psittaci in the pigeon fanciers is compatible with the known avian reservoir for this infection. The particularly high prevalence of antibodies to C. pneumoniae suggests that complex interactions may be occurring in a population exposed to two chlamydial organisms, whereby infection with one species may provoke an anamnestic response against other chlamydial organisms with which the subject has previously been infected.

Prevalence of high hematocrits in patients with interstitial lung disease in Mexico City

Erythrocytosis, a known response to chronic hypoxemia, is considered infrequent in interstitial lung diseases. We studied the prevalence of high hematocrit (Hct) values and the relationship between Hct and SaO2 in 79 patients with chronic pigeon breeder's lung (PBL) and 34 with idiopathic pulmonary fibrosis (IPF), all of whom lived in the Mexico City metropolitan area (2,240 m above sea level). Lung biopsy was performed in 31 patients with IPF and 71 with PBL. We analyzed only one simultaneous measurement of Hct and SaO2 per patient (usually the initial measurement) before treatment. No additional cause for anemia or erythrocytosis was detected. Forty-eight percent of the patients with PBL (38/79) and 62 percent of those with IPF (21/34) had high Hct values (greater than 2 SD above mean values for Mexico City); in 14 (12.3 percent) of the 113 patients (nine with PBL and five with IPF), the Hct was above 60 percent. The Hct and SaO2 values displayed a poor correlation for the whole group: Hct = 65.7-0.16(SaO2), r = 0.24, p = 0.012. The correlation between Hct and SaO2 was nonsignificant if patients were separated by diagnosis. For an SaO2 of less than 80 percent, the slope of SaO2 vs Hct was zero. Half of our patients with PBL and IPF had Hct values that were high for the altitude. In most cases, Hct responses fell within the confidence limits reported as normal at high altitudes. We found a poor relationship between Hct and awake SaO2.

Difference in the phenotypes of bronchoalveolar lavage lymphocytes in patients with summer-type hypersensitivity pneumonitis, farmer's lung, ventilation pneumonitis, and bird fancier's lung: report of a nationwide epidemiologic study in Japan

We performed a nationwide epidemiologic study of hypersensitivity pneumonitis (HP) in Japan by questionnaire and found that 835 cases of HP were recognized during the 1980s; 74.4% were summer-type HP, 8.1% farmer's lung, 4.3% ventilation pneumonitis, 4.1% bird fancier's lung, 2.3% other types, such as chemical worker's lung, and 6.8% of unknown causative agent. It was found that the CD4/CD8 ratios of bronchoalveolar lavage (BAL) lymphocytes were significantly different with the type of disease. The ratio was 0.6 +/- 0.1 (mean +/- SEM) in summer-type HP (N = 271), 4.4 +/- 0.7 in farmer's lung (N = 22), 1.6 +/- 0.3 in ventilation pneumonitis (N = 19), and 2.0 +/- 0.5 in bird fancier's lung (N = 19). In farmer's lung, the CD4/CD8 ratio in smokers was 6.2 +/- 1.9 (N = 6) in contrast with 3.4 +/- 0.7 for nonsmokers (N = 16) (p less than 0.05). It has been generally considered that the phenotypes of BAL lymphocytes in patients with HP are predominately CD8 cells. Our present results, however, indicate that the phenotypes of BAL lymphocytes vary with the type of HP, probably depending on factors such as causative agent, smoking, or staging of the disease.

Clubbing in hypersensitivity pneumonitis. Its prevalence and possible prognostic role

To know the prevalence and prognostic significance of finger clubbing in hypersensitivity pneumonitis induced by avian antigen, this physical sign was evaluated in 82 patients who were followed up from 1 to 5 years (mean, 2.6 years). According to clinical, roentgenographic, and functional criteria, the patients were classified in one of three stages at admission as well as at least 1 year later. Digital clubbing was retrospectively recorded as present or absent by physical examination. Our results showed that 44 patients (51%) included in this study presented clubbing at the time of diagnosis. Sixteen of these patients presented with worsening of their lung disease, whereas only 5 of the 38 patients without clubbing incurred a worsening of their condition. This finding suggests that digital clubbing is frequent in pigeon breeder's disease and may help to predict clinical deterioration.

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.

[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.

Chronic simple bronchitis in pigeon fanciers. Relationship of cough with expectoration to avian exposure and pigeon breeders' disease

The prevalence of chronic bronchitis and its relationship to antigenic exposure was studied in a population of pigeon fanciers. Two hundred and eighty seven fanciers completed a questionnaire regarding symptoms and circumstances of avian exposure and had IgG antibody to pigeon gammaglobulin measured by an enzyme linked immunosorbent assay. Chronic bronchitis occurred in 26.2 percent of nonsmoking fanciers and increased in prevalence as antibody levels rose (p less than 0.001). Although significantly more common (p less than 0.005) in the 85 (29.6 percent) fanciers who also had typical delayed symptoms of pigeon breeders' disease (PBD), chronic bronchitis was the only manifestation of the disease in 24 (8.4 percent) of the population surveyed. Chronic bronchitis was not related to the intensity or duration of avian exposure suggesting that host factors are more important in its pathogenesis. Chronic bronchitis must be considered to be an integral part of the clinical spectrum of PBD.

A survey of P1-antibodies in Scottish pigeon fanciers

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

Budgerigar-fancier's lung: the commonest variety of allergic alveolitis in Britain

A questionnaire survey of 1005 consecutive attenders at four outpatient clinics yielded 117 (12%) budgerigar fanciers (exposed to budgerigars- known in North America as parakeets-for at least three months) and 296 (29%) former fanciers. Twnety had precipitins to budgerigar serum or droppings or both, and 10 of these together with 39 precipitin-negative patients reported undue breathlessness on exertion during exposure to buderigars. These 59 patients were investigated further, seven completing a series of inhalation provocation tests with budgerigar antigens designed to confirm or exclude budgerigar-fancier's lung (BrFL). Typical positive responses were obtained from four current and one former fancier. The prevalence of confirmed BrFL among the 11n current budgerigar fanciers was 3.4% (four cases). This was biased, however, by the inclusion of one patient whose attendance at the surveyed clinic was attributable to the disease. With the exclusion of this patient, confidence limits suggested that the true prevalence of BrFL among current budgerigar fanciers in the general population lies between 0.5% and 7.5%, which is similar to the prevalence of farmer's lung in farm workers. In view of the enormous population at risk, however, this implies that BrFL rather than farmer's lung is by far the commonest type of allergic alveolitis in Britain.

Pigeon breeders' disease--a prevalence study and review

Among fifty-three Salt Lake City, Utah area pigeon fanciers, 21% were found to have the clinical picture of pigeon breeders' disease. This is a much higher frequency than has been observed previously. Abnormal spirometry and increased skin reactivity to pigeon sera were found more often, statistically significantly, in symptomatic than in exposed asymptomatic fanciers. Pigeon breeders' disease is associated with a variety of abnormal findings; skin test, precipitins, pulmonary function changes and radiographic derangements; but unfortunately none of these are diagnostic. Pigeon breeders' disease is best identified by clinical criteria.