RESUMEN
To investigate the contribution of direct cytotoxicity and immune-mediated hypersensitivity to the pathogenesis of amiodarone pneumonitis, we evaluated cells recovered by bronchoalveolar lavage from 13 patients with amiodarone pneumonitis. Alveolar macrophages from all patients contained two types of abnormal inclusions: small clear vacuoles and large phagolysosomes containing phospholipid in lamellar structures, abnormalities previously attributed to direct cytotoxicity from amiodarone. However, these changes were always associated with abnormalities in the numbers and types of immune and inflammatory cells present in the lower respiratory tract, which closely resemble those seen in hypersensitivity pneumonitis associated with inhaled antigens. Following discontinuation of amiodarone and institution of corticosteroid therapy, clinical improvement correlated with a return toward normal in the pattern of inflammatory cells present in the lung, although alveolar macrophages continued to display evidence of drug-induced cytotoxicity. These findings support the possibility that a cell-mediated immune response usually plays a role in the pathogenesis of amiodarone pneumonitis, although direct cytotoxicity may predispose these patients to the development of this abnormal immune response.
Asunto(s)
Alveolitis Alérgica Extrínseca/inducido químicamente , Amiodarona/efectos adversos , Bronquios/efectos de los fármacos , Anciano , Alveolitis Alérgica Extrínseca/patología , Bronquios/citología , Bronquios/ultraestructura , Separación Celular , Femenino , Humanos , Inmunidad Celular , Inflamación/patología , Recuento de Leucocitos , Activación de Linfocitos , Linfocitos/clasificación , Macrófagos/ultraestructura , Masculino , Microscopía Electrónica , Persona de Mediana Edad , Irrigación TerapéuticaRESUMEN
Two therapeutic trials aimed at determining whether a high-dose inhaled corticosteroid, beclomethasone dipropionate (BDP), could reduce or suppress a long term and continuous treatment with a systemic corticosteroid, triamcinolone acetonide (TA), were carried out in a homogeneous population of severe, steroid-dependent asthmatics. The first one was a controlled, double-blind versus placebo trial involving 25 patients followed up for 5 months. The second one was an open trial involving 105 patients followed up for 12 months. In both trials the mean doses of TA were reduced by 60 to 65 per cent, and TA could be totally or nearly totally suppressed in almost 60 per cent of the cases with clinical and functional results that were equal or superior to those previously obtained with systemic corticosteroid therapy. It is concluded that: (a) continuous systemic corticosteroid therapy in mean doses of more than 5 mg/day of prednisone equivalent is now rarely indicated in patients with steroid-dependent asthma, and (b) inhaled corticosteroid therapy with BDP could be extended to cases of non steroid-dependent asthma inadequately controlled by bronchodilators.
Asunto(s)
Asma/tratamiento farmacológico , Beclometasona/uso terapéutico , Triamcinolona Acetonida/uso terapéutico , Administración por Inhalación , Adulto , Aerosoles , Beclometasona/administración & dosificación , Ensayos Clínicos como Asunto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Triamcinolona Acetonida/administración & dosificaciónRESUMEN
Four cases of amiodarone-induced restrictive, hypoxaemic lung disease are described. The cumulative dosages of amiodarone were relatively low (30 to 100 g). Alveolar lavage studies showed a lymphocytosis and study of the lymphocytic sub-populations showed an increase in the OKT8 group, and an inversion of the OKT4/OKT8 ratio. The outcome was favourable on withdrawal of amiodarone and steroid therapy. The immunological origin of this form of lung disease was confirmed. Two patients had renal failure; in the first case, hypercalcaemia, hyperphosphoremia and renal calcification were observed. The second patient had endo- and extracapillary glomerulonephritis with C3 deposits and circulating immune complexes. Renal failure regressed in both cases on withdrawal of amiodarone and with steroid therapy.