Validation of Alveolar Probe-based Confocal Laser Endomicroscopy Descriptors in Diffuse Parenchymal Lung Diseases

Diffuse parenchymal lung diseases (DPLD) include a variety of respiratory conditions that affect either the pulmonary interstitium or the alveolar space . The etiological diagnosis of DPLD is often challenging, because of the large number of pathological entities involved, which share close clinical and radiological presentations. High resolution Chest CT, a key diagnostic procedure in DPLD, is subject to significant inter-observer analysis variations, so that the diagnosis sometimes requires a surgical or transbronchial lung biopsy sampling. This invasive procedure is not devoid of morbidity and may be impossible to perform in fragile patients. Therefore, the definite diagnosis of DPLD is usually achieved following a multi-disciplinary expert consensus, based on careful medical history, chest CT and bronchoalveolar lavage examinations. Alveolar probe-based confocal laser endomicroscopy (pCLE) is a mini invasive endoscopic technique that allows distal lung microscopic imaging in vivo, during a flexible bronchoscopy performed under topical anaesthesia. Since 2006, Alveolar pCLE has been used in a monocentric clinical trial at the Rouen University Hospital in more than 200 patients and healthy volunteers. This allowed the first pCLE in-vivo description of normal pulmonary acinus, and confirmed the safety of the technique.