Pigeon hypersensitivity pneumonitis: immunohistochemical demonstration of the causative antigen in the lung.

A number of clinicopathological manifestations may define the presence of hypersensitivity pneumonitis. Histological study is used to establish the diagnosis and to differentiate the disease from other respiratory disorders. This case report suggests that immunohistological demonstration of the causative antigen in the lung may be a useful diagnostic approach in cases of pigeon hypersensitivity pneumonitis. A 52 year-old woman was studied. She had a prior history of pigeon exposure, and lived in an area with a high prevalence of tuberculosis. Her clinical presentation, respiratory function tests and imaging studies revealed a predominant interstitial lung disease. The results of antiavian antibodies, bronchoalveolar analysis, and other laboratory parameters were non-diagnostic. A lung biopsy showed a prominent granulomatous reaction with a sarcoid-like appearance in some areas, and an interstitial infiltration constituted by lymphocytes, plasma cells and foamy macrophages. Although the disease manifestations were compatible with hypersensitivity pneumonitis, we decided to study the causal antigen by immunohistochemistry. The use of a polyclonal antibody raised against pigeon serum showed a predominant cytoplasmic immunostaining in multinucleated giant cells and histiocytes from lung granulomas. Other respiratory disorders were reasonably excluded. Previous exposure to a known antigen may support the diagnosis of hypersensitivity pneumonitis. Although the inhalation of organic dusts may be clinically evident, the aetiology is commonly evaluated by different challenge tests or immunological methods. We propose that the study of pigeon antigen by immunohistochemistry may be used as part of the diagnostic approach for hypersensitivity pneumonitis.

Anti-avian antibodies and rheumatoid factor in pigeon hypersensitivity pneumonitis.

BACKGROUND: Although several immunological abnormalities may be present in pigeon hypersensitivity pneumonitis (HP), few specific hallmarks have been described. OBJECTIVE: To determine whether the presence of rheumatoid factor (RF) could be useful to discriminate pigeon HP from asymptomatic breeders (AB) and other interstitial lung diseases. METHODS: Fifty-three patients with pigeon HP, 47 AB, 31 idiopathic pulmonary fibrosis (IPF) patients and a rheumatoid arthritis (RA) group were studied. IgM RF was determined through enzyme-linked immunosorbent assay (ELISA) and western blot using human IgG and IgG Fc fragment as antigens. IgG and IgA anti-avian antibodies (AA) against pigeon serum antigen were also measured. The use of F(ab')2 fraction of peroxidase-labelled anti-human immunoglobulins prevented endogenous interferences. Possible cross-binding of RF with avian antigens and the reactivity against human IgG by AA were studied. RESULTS: RF tests were frequently positive in HP (52.8%) in comparison to AB (4.2%) and IPF (12.9%; P = 2.6 x 10-10 and 4.1 x 10-5). Therefore, the presence of RF in pigeon HP showed a sensitivity of 52% and was highly specific considering the results of AB and IPF (95 and 87%, respectively). The RA group revealed positive RF but negative AA tests. RF activity was confirmed through western blot using purified IgG Fc fragment. Overlapping levels of IgG and IgA AA were found in HP and AB. The frequency of AA was low in IPF. The cross-reaction of RF with avian antigens was excluded, and no reactivity against human IgG by AA was detected. Other endogenous interferences were ruled out. CONCLUSION: No single immunological test may definitively distinguish pigeon HP from AB and other interstitial lung disorders; however, positive RF, together with high AA levels, seems to be useful in differentiating the diagnosis.

[Extrinsic allergic alveolitis. Clinical experience at the Instituto National de Enfermedades Respiratorias (INER)]. / Alveolitis alérgica extrínseca. Experiencia clínica del INER.

Extrinsic allergic alveolitis is an interstitial lung disease caused by exposure to a variety of inhaled antigens. In Mexico, the most frequent form is due to the inhalation of avian antigens, markedly pigeon proteins. Depending on type and time exposure, the disease presents different clinical forms usually characterized by progressive dyspnea, ground glass or reticulonodular images on chest x rays, a restrictive functional pattern, rest hypoxemia worsening with exercise, and increase of T lymphocytes in bronchoalveolar lavage with an inversion in the helper/suppressor ratio. In this paper, we discuss a 15-year experience with this pathological problem in Mexico, emphasizing the differences with this disorder in Caucasian populations. Generally, our patients display a chronic form of the disease, which evolves to fibrosis in about one-half of the patients. In this sense, the diagnostic, prognostic, and therapeutic focusing exhibit different elements, and thus the development of clinical and basic research is strongly required.

On the correct determination of reference values for serum antibodies against pigeon serum antigen using a group of healthy blood donors

An ensymatic immunoassay was developed in order to evaluate the statistical distribution of IgG serum antibodies against pooled pigeon ser antigen in 102 healthy blood donors (HBD). A non-normal distribution was obtained as demonstrated by abnormal values of skewness (2.02) and kurtosis (6.50). A cut-off point (0.120) was determined from the mean plus 2 standard derivations of the optical density values obtained in the HBD group. This value was able to segregate 94 percent of subjects. However, when calculation of the mean less 2 SD was performed to delimit 95 percent of the samples, an aberrant negative value was obtained. In contrast, when the nonparametric method of percentile calculation was applied, an optical density value of 0.130 discriminated 97.5 percent of samples. In addition, the interval between p97.5 and p2.5 delimited 95 percent of samples. We conclude that when reference values and cut-off point are determined from an enzymatic immunoassay, careful analysis of the statistical distribution of reference values is necesary in order to avoid the inappropiated in this study for antibodies against pigeon serum antigens

[Lung function in workers in a chicken slaughterhouse in the city of Maracaibo, Venezuela]. / Estudio de la función pulmonar en trabajadores de una industria beneficiadora de pollos en la ciudad de 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.

[Capability of clinical and laboratory findings to predict the grade of fibrosis and the diagnosis in diffuse interstitial lung diseases]. / Capacidad de clínica y laboratorio para predecir el grado de fibrosis y el diagnóstico en enfermedades pulmonares intersticiales difusas.

Our objective was to assess the capacity of clinical and laboratory information to predict findings in the lung biopsy in interstitial lung diseases (ILD). We studied 121 patients with ILD as a cohort recruited in our institute from 1983 to 1987 with the diagnosis of hypersensitivity pneumonitis (HP) and usual interstitial pneumonia (UIP). Histologic diagnosis (HP vs UIP) and degree of fibrosis (< 50% of the biopsy surface vs > or = 50%) were used as the gold standard to compare a series of clinical and laboratory variables in the initial assessment. We used a stepwise logistic regression model to predict the biopsy results. The model was calculated in half of the patients selected by random sampling, and the calculated model was tested in the other half of the patients. Variables found to predict degree of fibrosis were (with relative risk RR and 95% confidence interval): a radiographic pattern of honeycombing (RR 5.0 from 0.9-29), digital clubbing (RR 8 from 1.4-48) and gender (RR 2.9 from 0.4-20). This model classified correctly 72% of the biopsies, with a sensitivity of 0.38, a specificity of 0.85 and a kappa of 0.25 +/- 0.19 (p = 0.17 NS). For histologic diagnosis (NIU vs NH), the model included gender (RR 6.6, 1.3-33), honeycombing (RR 1.6, from 0.4-6.0), digital clubbing (RR 4.6, from 1.2-18), and vital capacity expressed as percent of predicted (RR 0.96, from 0.92-1.00).(ABSTRACT TRUNCATED AT 250 WORDS)

Enfermedad del criador de palomas: presentación de cinco casos / Pigeon breeder's disease: report of 5 patients

En este trabajo se describen las manifestaciones clínicas y de laboratorio de cinco pacientes con la Enfermedad del Criador de Palomas, los cuales fueron diagnosticados y atendidos en nuestro Hospital en los últimos dos años. Se hace énfasis en las diferentes formas de presentación clínica, así como la importancia que tiene el estudio serológico para el diagnóstico, al demostrarse la presencia de anticuerpos precipitantes en el suelo de estos pacientes en contra de antígenos presentes en el suero y en las excretas de las palomas. En uno de los casos, tuvimos la oportunidad además de estudiar a varios de sus familiares. Clínicamente nuestros pacientes tuvieron una evolución crónica (promedio 27.4 meses) lo que sugiere exposición prolongada a los antígenos aviarios y la falta de diagnóstico oportuno. Serológicamente, en los cinco pacientes detectamos la presencia de anticuerpos precipitantes en contra de antígenos de paloma. En los familiares del caso estudiado, aunque clínicamente estaban asintomáticos, en tres de los nueve encontramos los mismos anticuerpos precipitantes, por lo que consideramos la posibilidad de que algunos factores genéticos pueden ser importantes en la expresión de la respuesta inmune humoral a los antígenos aviarios, que ocurre en esta forma de neumonitis por hipersensibilidad

[Pneumonitis caused by hypersensitivity to pigeons. (I). Clinical value of counterimmunoelectrophoresis for detection of specific antibodies in the serum]. / Neumonitis por hipersensibilidad a palomas. (I). Valor clínico de la contrainmunoelectroforesis (CIE) para detectar anticuerpo específico en suero.

Hypersensitivity pneumonitis due to pigeon's exposure (pigeon's breeder disease) is a interstitial lung disease caused by immune mechanisms after sensitization to pigeon serum antigens. An immunological test, counterimmunoelectrophoresis (CIE), has been developed to recognize the humoral immune response against pigeon serum and dropping antigens, in a simple, low cost and fast test than other cumbersome tests presently in use. The CIE has high sensibility and specificity (X2 = 35.8 p 0.001) that guarantee its clinical usefulness. When Pigeon breeder's disease is suspected on clinical grounds, the CIE test is indicated to confirm diagnosis.