Reduced FEV1/FVC and FEV1 in the Normal Range as a Physiological Variant.

BACKGROUND: Healthy individuals without respiratory symptoms can sometimes present with low FEV1/FVC. The objective of this study was to characterize and compare subjects without symptoms and with reduced FEV1/FVC but normal FEV1 with subjects with mild obstructive lung disease. METHODS: Fifty healthy subjects with FEV1/FVC below the fifth percentile of reference values (normal variants) were compared with 52 subjects with asthma and 48 subjects with COPD who had similar FEV1/FVC. RESULTS: Subjects without symptoms were more likely to be male, younger, and taller, and to have higher FVC%, FEV1%, mid expiratory flow, and terminal flow than subjects with obstructive disease. A receiver operating characteristic curve analysis determined that the best separation between the groups was provided by age < 55 y, height ≥ 167 cm, and FVC > 105%. A logistic regression analysis confirmed that male sex, age, FVC%, and FEF75 (Forced expiratory flow in 75% of forced vital capacity) were significant factors for discriminating subjects without symptoms from those with obstructive lung disease. CONCLUSIONS: A reduced FEV1/FVC may be a normal finding in younger-to-middle age male subjects with an FVC% value above the mean predicted value, especially when terminal flow is within the normal range.

Chronic hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HSP) is a common interstitial lung disease resulting from inhalation of a large variety of antigens by susceptible individuals. The disease is best classified as acute and chronic. Chronic HSP can be fibrosing or not. Fibrotic HSP has a large differential diagnosis and has a worse prognosis. The most common etiologies for HSP are reviewed. Diagnostic criteria are proposed for both chronic forms based on exposure, lung auscultation, lung function tests, HRCT findings, bronchoalveolar lavage, and biopsies. Treatment options are limited, but lung transplantation results in greater survival in comparison to idiopathic pulmonary fibrosis. Randomized trials with new antifibrotic agents are necessary.

Doença pulmonar intersticial associada a bronquiolite respiratória / Respiratory bronchilitis-associated interstitial lung disease

A doença pulmonar intersticial associada a bronquiolite respiratória faz parte do espectro anatomopatológico das lesões pulmonares infiltrativas difusas induzidas pela fumaça de cigarro. Raramente tem apresentação clínico-funcional exuberante. Descrevemos dois casos diagnosticados por biópsia pulmonar aberta, caracterizados por dispnéia de evolução insidiosa, baqueteamento digital, lesões císticas à tomografia computadorizada e hipoxemia ao exercício. Enfatizamos considerar, em indivíduos tabagistas, a doença pulmonar intersticial associada a bronquiolite respiratória no contexto das pneumopatias intersticiais císticas, juntamente com a linfangioleiomiomatose, o granuloma eosinofílico e a fibrose pulmonar idiopática.