A role of probe-based confocal laser endomicroscopy for diagnosis of pulmonary alveolar proteinosis

Abstract

Introduction. Probe-based confocal laser endomicroscopy (pCLE) of distal airways is a new technology allowing visualization of cells and structures that have autofluorescence. Endomicroscopic features of a number of rare lung diseases including pulmonary alveolar proteinosis (PAP) has not been yet investigated. The purpose of the study was to describe endomicroscopic features of PAP before and after the whole lung lavage (WLL). Methods. pCLE was performed during bronchoscopy in 6 PAP patients before and after the WLL. In certain lung segments, pCLE was done under the HRCT control. More than 1300 endomicroscopic images have been evaluated using a semiquantitative method. Results. We found floating fluorescent amorphous aggregates sticking with alveolar macrophages in all the patients. These changes reduced after the WLL. pCLE allowed to reveal PAP characteristic features not only in lung segments with «crazy paving» HRCT sign but also in lung zones without any HRCT changes. Conclusions. pCLE can detect specific PAP features both at presence and absence of HRCT signs that confirms diffuse injury of the lung parenchyma. pCLE could be a helpful tool for diagnosis and assessment of treatment efficacy in patients with PAP.