HIGH DEFINITION VIDEOBRONCHOSCOPY FOR THE DIAGNOSIS OF AIRWAY INVOLVEMENT IN SARCOIDOSIS: THE ENHANCE SARCOIDOSIS MULTICENTER STUDY.

BACKGROUND: The ability of high-definition (HD) videobronchoscopy to detect airway involvement in sarcoidosis was not evaluated previously.

RESEARCH QUESTION: What is the role of HD videobronchoscopy in the identification of sarcoidosis-associated airway abnormalities (AA)? What are the patterns of AA more commonly observed and more frequently associated with the detection of granulomas in endobronchial biopsy (EBB)?

STUDY DESIGN AND METHODS: In this prospective, international, multicenter cohort study, consecutive patients with suspected sarcoidosis underwent airway inspection with a HD videobronchoscope and EBB using a standardized workflow. AA were classified according to six patterns defined "a priori": nodularity, cobblestoning, thickening, plaque, increased vascularity, and miscellaneous. We assessed diagnostic yield of EBB, prevalence of AA, diagnostic yield of EBB and interobserver agreement for different patterns of AA.

RESULTS: AA were identified in 64/134 (47.8%) sarcoidosis patients, with nodularity (23, 17.2%), plaque (19, 14.2%) and increased vascularity (19, 14.2%) being the most prevalent. The diagnostic yield of EBB was 36.6%. AA were significantly more prevalent in patients with than in those without non-necrotizing granulomas in EBB (67.4% VS 36.5%, P=0.001). Likewise, parenchymal disease on CT was significantly more common in patients with than in those without non-necrotizing granulomas in EBB (79.6% VS 54.1%, P=0.003). On a per-lesion analysis, non-necrotizing granulomas were seen especially in EBB taken from areas of cobblestoning (9/10, 90%) and nodularity (17/29, 58.6%). The overall diagnostic yield of random EBB was low (31/134, 23.1%). The interobserver agreement for the different patterns of AA was fair (Fleiss k=0.34).

INTERPRETATION: In a population with a large prevalence of white Europeans, HD videobronchoscopy detected AA in approximately half of sarcoidosis patients. The diagnostic yield of EBB was higher in patients with parenchymal involvement on CT and in those with airway abnormalities, especially if manifesting as cobblestoning and nodularity.

CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, identifier NCT4743596.