Anti-Fibrotic Drug Development (AFDD) Summit 2017

New Standards in Fibrosis Quantification: the Value of Label-free Second Harmonic Generation

By Dr Mathieu Petitjean, CEO, MedNest, USA

Fibrosis is associated with excessive accumulation of extracellular matrix in response to persistent injury, inflammation, and abnormal wound healing. The current standard to assess fibrosis are conventional staining and histopathological criteria scoring. This assessment has limitation as it uses a narrow range scoring (when scoring exists), it is prone to observer variations, and requires multiple histopathology workflows and stains.

• Here, we use second harmonic generation (SHG) together with two-photon excitation fluorescence (2PE) imaging and computerized image analysis algorithms to provide a novel, sensitive, and efficient method for collagen quantitation. We extract information on the collagen fibers in various animal models to assess fibrosis as it advances or regress in response to therapeutic compounds.

• We present animal models including NASH livers, IPF lungs and UUO kidneys treated with or without reference anti-fibrotic drugs including Nintedanib and Pirfenidone. 

• In addition to basic quantifiable metrics including total collagen, we offer novel analysis capabilities that conventional method are not able to provide such as tissue regional segmentation (for livers, lung, kidney), collagen network structure, collagen fiber density, etc. These metrics may be the key to better fibrosis scoring and staging. 

• Due to the nature of the technology, this stain-free SHG/2PE imaging and automated image analysis allow for a reliable and quick turnaround time for data results.

*We thank GenScript and Intercept Pharmaceuticals for providing the conventional staining images and respective graphs. We thank HistoIndex and A*STAR (Singapore) for their assistance in the image analysis of the IPF rodent model images.