To compare the usefulness of specimens obtained by bronchoalveolar lavage (BAL) and using a protected specimen brush (PSB) in the diagnosis of nosocomial pneumonia, both procedures were performed via fiberoptic bronchoscopy just after death in a series of 20 ventilated patients who had not developed pneumonia before the terminal phase of their disease and who had no recent changes in antimicrobial therapy. These results were compared with both histologic and microbiologic postmortem lung features in the same area. The total number of bacteria obtained by culture of lung segments and the latters' histologic grade were closely correlated (rho = 0.79, p < 0.0001). PSB and BAL quantitative culture results were strongly correlated with lung tissue values (rho = 0.67 and 0.75, respectively; p < 0.0001). Using discriminative values of > or = 10(3) and > or = 10(4) bacteria/ml to define positive PSB and BAL cultures, respectively, these techniques identified lung segments yielding > or = 10(4) bacteria/g tissue with sensitivities of 82 and 91% and specificities of 89 and 78%, respectively. Moreover, upon direct observation, the percentage of BAL cells containing intracellular bacteria was closely correlated with the total number of bacteria obtained from corresponding lung samples (p < 0.001). These findings indicate that bronchoscopic PSB and BAL samples very reliably identify both qualitatively and quantitatively microorganisms present in lung segments with bacterial pneumonia, even when the infection develops as a superinfection in a patient already receiving antimicrobial treatment for several days.

To evaluate the effect of cigarette smoking on the number, distribution, and differentiated state of dendritic cells (DC) and Langerhans cells (LC) in the human lung, we have quantitated the number of these cells present in the bronchioles and alveolar parenchyma of lung tissue from nonsmokers and cigarette smokers using anti-CD1 monoclonal antibodies which react preferentially with DC (M241) and LC (T6). M241+ DC were found in the bronchiolar submucosa and alveolar parenchyma of nonsmokers; T6+ LC were present within the bronchiolar epithelium. Cigarette smoking was associated with a twofold increase in the total number of cells of DC/LC lineage and a 30-fold increase in the number of T6+ cells, many of which contained Birbeck granules (LC), present in the alveolar parenchyma. Most LC found in the parenchyma of smokers were observed in close association with areas of alveolar type II pneumocyte hyperplasia. Cigarette smoking did not change the number of differentiated state of cells of DC/LC lineage within the bronchioles. Both DC and LC are present in the human lung. Cigarette smoking has an important effect on the number, distribution, and differentiated state of these cells, which may explain why most adult patients who develop Langerhans cell granulomatosis are smokers.

No abstract

This study describes the chest radiographs of 50 adult patients with histologically verified histiocytosis X, proposes a radiological classification, and examines the role of radiology in assessing the prognosis of the disease. Radiologically the lesions predominate in the middle and lower lung fields, usually sparing the costophrenic angles, and are typically micronodular, reticular, or cystic. These features are especially suggestive of histiocytosis X if lung volume is normal or increased, there is an associated pneumothorax, they occur in a young male and there are no other intrathoracic changes (pleural or mediastinal). The three evolutionary patterns of improvement, stabilisation, and worsening are analysed with respect to the initial radiological features; one which carries a good prognosis is sparing of both costophrenic angles.Pulmonary histiocytosis X (HX) is a chronic interstitial disease characterised by the presence of multiple specific granulomas which contain many Langerhans cells.The radiological features of this disease comprise nodular, reticulonodular, or honeycomb patterns which classically appear "predominantly in the upper lung fields".' However, in our experience the radiographic findings often depart from the classic description.The aims of this study, therefore, were: (1) to use a defined group of adults with HX to describe the chest radiological features of the disease; (2) to develop a qualitative method of analysing the chest radiographs; and (3) Follow-up information extending from one to 12 years was available for 37 patients; 26 of these were followed for over three years (mean = 5 4 years). RADIOGRAPHIC STUDYOnly posteroanterior chest radiographs were considered; tomography was not included. In assessing prognosis, special attention was paid to the earliest and latest films.

The characteristic lesions of pulmonary Langerhans cell histiocytosis (LCH) associate destructive granulomas containing large numbers of Langerhans cells and cysts. The lesions are usually considered to develop around small airways, and cysts are thought to result from destruction of the bronchiolar wall by the granulomatous reaction. However, the extent to which the granulomatous reaction is truly bronchocentric remains unknown, and the mode of formation of the cysts has not been defined. By using serial sections, this study aimed to explore further the relationships between pulmonary LCH lesions and distal airways, and the development of cysts. The results demonstrated that the granulomatous process of pulmonary LCH affected exclusively small airways, in an acinar distribution. The lesions extended without interruption along the bronchiolar axis, forming a continuous sheath around distal airways. The granulomatous reaction seemed to progress along the bronchiolar axis over time, extending the abnormalities in both the proximal and distal directions. Cystic lesions resulted from the destruction of the bronchiolar wall and progressive dilatation of the lumen, subsequently circumscribed by fibrous tissue. Because pulmonary LCH lesions affect and progressively destroy distal airways, it may be proper to consider the disease a bronchiolitis rather than an interstitial lung disorder.