Fibred confocal fluorescence microscopy in the diagnosis of interstitial lung diseases

Abstract

Background: Accurate diagnosis is critical to both therapeutic decisions and prognostication in interstitial lung diseases (ILD). However, surgical lung biopsies carry high complication rates. Fibred confocal fluorescence microscopy (FCFM) offers an alternative as it can visualize lung tissue in vivo at the cellular level with minimal adverse events. We wanted to investigate the diagnostic utility, and safety of using FCFM for patients with ILD.Methods: In patients with suspected ILD, FCFM images were obtained from multiple bronchopulmonary segments using a miniprobe inserted through the working channel of a flexible bronchoscope. The procedure was performed under moderate sedation in an outpatient setting. Morphometric measurements and fibre pattern analyses were co-related with computed tomography (CT) findings and patients' final diagnoses based on multi-disciplinary consensus.Results: One hundred and eighty four segments were imaged in 27 patients (18 males) with a median age of 67 years (range, 24-79 years). They were grouped into chronic fibrosing interstitial pneumonia (16 patients) and other ILDs. Six distinct FCFM patterns were observed: normal, increased fibres, densely packed fibres, hypercellular, thickened fibres and others/non-specific. The pattern resembling densely packed fibres was seen in at least one segment in 68.8% patients with chronic fibrosing interstitial pneumonia, but only 36.4% in other ILD (P=0.097). An association between inflammatory patterns on CT and a hypercellular pattern on FCFM was also found (P<0.001).Conclusions: Our study shows the potential of FCFM in classifying ILD, but its role in further diagnosis remains limited.

Confocal Laser Endomicroscopy as a Guidance Tool for Transbronchial Lung Cryobiopsies in Interstitial Lung Disorder

“…It has previously been shown that elastin is autofluorescent with the CLE wavelength of 488 nm [10] and that an increase and distortion of the elastin fibers is found in the histology of fibrotic lung [14, 15], comparable with our CLE findings. The CLE pattern that we found in densely fibrotic areas resembles the previously described (densely packed fiber) pattern by Meng et al [14], which they hypothesized to be indicative of late-stage scarring.…”

“…The CLE pattern that we found in densely fibrotic areas resembles the previously described (densely packed fiber) pattern by Meng et al [14], which they hypothesized to be indicative of late-stage scarring. Uncertainty remained due to the unavailability of histology specimens of cryobiopsy and surgical biopsy as a reference standard.…”

Automated evaluation of probe-based confocal laser endomicroscopy in the lung

“…The presented method aims to quantify features that have previously been reported to change due to different DPLDs, such as increase/decrease of elastic fibres, disorganization of elastic network and enlarged axial elastic fibre bundle diameter [14][15][16][17]. Similar elastin thickness values were found here as in other work [29], albeit with a higher variability.…”

“…With a multitude of technical improvements over the last 15 years to overcome the low specificity of autofluorescence defects [10,11], pCLE has shown promise as a diagnostic method to visualize lung tissue in vivo [12,13]. Multiple studies [14][15][16][17] have investigated the structural changes of lung tissue caused by different DPLDs and specifically highlighted increased elastin fibre thickness, density of fibres and number of cellular structures as important features. The aim of this study was to develop a fully automatic workflow for quantifying these structural properties using pCLE measurements and to perform a preliminary assessment of their diagnostic potential.…”

Avances en tomografía de coherencia óptica y endomicroscopía confocal láser en enfermedades pulmonares

“…Se han realizado varios estudios para identificar características específicas en imágenes por pECL en EPIs. Meng et al [83] identificaron seis patrones diferentes para discriminar una EPI fibrosante crónica de otras EPIs. Salaün et al [84] identificó nueve características específicas de ECL empleando datos de 80 individuos (59 pacientes con EPI, 21 sujetos sanos).…”