Comparative Usefulness of Bronchial Cryobiopsy vs Conventional Incisional Biopsy in Severe Asthma: Histopathological Evaluation

BACKGROUND: Histopathological analysis of bronchial tissue in patients with severe asthma makes it possible to characterize inflammatory and remodeling phenomena that are not identifiable using noninvasive biomarkers. Although bronchial cryobiopsy is considered an advantageous technique, its diagnostic utility compared with conventional forceps biopsy has not been clearly established. The objective of the present study was to compare the diagnostic performance of bronchial cryobiopsy and forceps biopsy in the histopathological evaluation of severe asthma. METHODS: A prospective comparative study was conducted in 27 patients with severe asthma who underwent bronchoscopy. Samples were obtained using both techniques, and histological and immunohistochemical findings were compared. RESULTS: Both techniques confirmed the high prevalence of remodeling, highlighting smooth muscle hyperplasia (85.2% with incisional biopsy, 81.4% with cryobiopsy) and basement membrane thickening (59.3% with incisional biopsy, 55.6% with cryobiopsy). Nonsignificant differences were observed between the techniques, although diagnostic sensitivity was greater with incisional biopsy. Cryobiopsy showed lower rates of epithelial denudation overall. However, in patients with bronchial obstruction, epithelial loss was consistently observed in cryobiopsy samples, possibly reflecting a technical limitation. The correlation between peripheral eosinophilia and submucosal tissue infiltrate was weak and nonsignificant with both techniques (r=0.168; P=.403). CONCLUSIONS: Bronchial cryobiopsy is an effective tool with a yield comparable to that of incisional biopsy for the assessment of deep structural remodeling. However, incisional biopsy maintains superior diagnostic sensitivity and diagnostic yield. The discordance observed between peripheral and tissue eosinophilia underscores the need for histological evaluation to complement peripheral biomarkers for the stratification and personalization of biological therapies in obstructive disease.