Enfermedad del pulmón del granjero: análisis de 75 casos / Farmer's lung disease: Analysis of 75 cases

Introducción: La enfermedad del pulmón de granjero (EPG) es una forma frecuente de neumonitis por hipersensibilidad, posiblemente infradiagnosticada. El objetivo de este estudio es describir las características clínicas, la evolución y los factores que influyen en el pronóstico de los pacientes con EPG. Pacientes y métodos: Estudio retrospectivo que incluyó a todos los pacientes diagnosticados de EPG por haber presentado una exposición ambiental de riesgo, una clínica, una función pulmonar y una radiología compatible, en los que se demostró sensibilización antigénica y/o una anatomía patológica concordante. Resultados: Se incluyeron 75 pacientes con EPG, 50 con forma aguda o subaguda (FAS) y 25 con forma crónica (FC). Un 44% de los pacientes (n=33) fue diagnosticado durante los meses de marzo y abril, especialmente aquellos con FAS en comparación con las FC (52 vs. 28%; p=0,0018). En las FAS la DLco presentó una mejoría durante el seguimiento (p=0,047). La determinación de anticuerpos IgG específicos fue positiva en 39 pacientes (78%) con FAS (44% de ellos frente a Aspergillus) y en 12 con FC (48%). La realización de la evitación antigénica (OR 9,26, IC 95% 1,3-66,7, p=0,026) y la administración de tratamiento inmunodepresor (OR 16,13, IC 95% 1,26-200, p=0,033) fueron los factores predictores de mejor evolución de la enfermedad. Conclusiones: La EPG presenta un inicio con predominio estacional en nuestro medio. Las FC presentan habitualmente determinación de anticuerpos IgG específicos negativos, a diferencia de las FAS, donde los anticuerpos frente Aspergillus son las más frecuentes. La evitación antigénica y el tratamiento inmunodepresor son posibles predictores de mejor evolución de la enfermedad (AU)

Introduction: Farmer's lung disease (FLD) is a common form of hypersensitivity pneumonitis possibly underdiagnosed in our midst. The aim of this study was to describe clinical characteristics, evolution and factors that influence the prognosis of patients with FLD. Patients and methods: A retrospective study that included all patients diagnosed with FLD presenting an environmental exposure risk, a clinic, lung function and a compatible radiology, in which antigen sensitisation was demonstrated and/or a concordant pathology. Results: We selected 75 patients with FLD, 50 with acute or subacute form (ASF) and 25 with chronic form (CF). Forty-four percent of patients (n=33) were diagnosed during the months of March and April, especially those with ASF compared to CF (52 vs. 28%; P=.0018). In the ASF group, DLco showed an improvement during follow-up (P=.047). The determination of specific IgG antibodies was positive in 39 patients (78%) with ASF (44% of them against Aspergillus) and CF 12 (48%). The realisation of antigenic avoidance (OR 9.26, 95% CI 1.3-66.7, P=.026) and the administration of immunosuppressive therapy (OR 16.13, 95% CI 1.26-200, P=.033) were predictors of better disease progression. Conclusions: FLD is predominantly seasonal in our environment. CF usually has a negative specific IgG antibodies unlike ASF, where antibodies against Aspergillus are the most common. The realisation of antigenic avoidance and immunosuppressive treatment are possible predictors of better disease progression (AU)

Clinical aspects of farmer's lung: airway reactivity, treatment and prognosis.

This study reviews the results of five clinical studies dealing with farmer's lung (FL). The total number of patients included was 107, with a mean age of 49 years. All patients were farmers with dairy cattle. The clinical symptoms, auscultatory findings, chest radiography, laboratory data, partial pressure of oxygen in arterial blood at rest (PaO2), dynamic spirometry (FVC and FEV1) and lung diffusing capacity of carbon monoxide (DLco) were recorded at the first visit to the hospital and one, three, six and twelve months later during the follow-up and every six months after that. Half of the patients with FL reported insidious onset of the disease, and 28% reported acute onset. Dyspnoea was reported by all patients, coughing was almost as common. A considerable proportion of the patients reported muscle and joint pains. Diffuse opacities were detected in the chest radiograms of 99 patients (93%): the more severe the radiological change, the more impaired the DLco value. A normal chest radiogram was seen in eight of the 107 patients at the first evaluation. Half of the patients showed a restrictive type of impairment of ventilatory function at the first evaluation. Lung diffusing capacity was less than 80% of the predicted value in 89% of the patients. Ninety-nine patients were initially challenged with histamine and twenty-two of them (22%) showed increased bronchial responsiveness. Bronchial hyper-reactivity was transient in most of the patients and might also fluctuate with exacerbation of FL symptoms. Specimens of the airway epithelium of FL patients were taken by rigid bronchoscope from five patients for electronmicroscope studies. Extensive bronchial damage to the airway epithelium associated with the presence of spore-like fungi was observed. Aspiration biopsy of the spleen was carried out on ten FL patients during their first visit to the hospital. Granuloma-like reactions were detected in the aspiration biopsy material of five FL patients. The granulomatous changes in the spleen had disappeared when the procedure was repeated on two patients at an asymptomatic stage of the disease. Ninety-three patients were included in a follow-up study with a mean follow-up period of 18.6 months. The patients with clinically less severe disease were observed without medication. It appeared that corticosteroid medication was usually started if the DLco value was less than 65% of the predicted value. Fourteen patients with a DLco value less than 65% were observed without medication and served as a control group for those on medication.(ABSTRACT TRUNCATED AT 400 WORDS)