Whole Slide Quantitative Image Analysis Can Demonstrate Bleomycin Induced Dose-Dependent Increases in Fibrotic Areas Within Histologically Stained Rat Lung Tissue

RationaleThe accurate classification and quantification of specific morphological and cellular components within the bleomycin (Bleo)-induced rodent lung tissue model is challenging. This study aimed to employ histology in combination with whole slide digital image analysis to quantify the extent of lesion formation and content within lung tissue from Bleo treated rats. MethodsMale SD rats, n=5 per group (Gr), were treated with either saline (Gr1) each day for 7 days or 1.5mg/Kg Bleo (Gr2) and 3.0mg/Kg Bleo (Gr3) on one dose occasion or 0.5mg/Kg Bleo (Gr4) and 1.0mg/Kg Bleo (Gr5) each day for 7 days. On day 22, lungs were fixed, paraffin embedded, sectioned and histologically stained using Picrosirius Red. Whole slide images of lung tissue were captured and analysis algorithms developed by OracleBio (using Definiens Tissue Studio® software) to define specific regions of interest (ROI) per section including Parenchyma and Lesion, excluding basal collagen. Collagen content and cell density can then be quant...