Development of a Tissue Image Analysis Algorithm for Celiac Drug Development

Abstract

Celiac disease, an immune-mediated condition related to gluten sensitivity, is gaining pharmaceutical development interest. Recent conversations with the US Food and Drug Administration (FDA) indicate pathology readouts from intestinal biopsies will continue to be a primary clinical trial endpoint. The existing methodology, the Marsh-Oberhuber score, is a qualitative assessment of celiac severity, combining a morphological criterion known as villous height to crypt depth ratio (VC), with an assessment of localized immune response, manually estimating intraepithelial lymphocyte (IEL) counts. A stereology and image analysis based whole slide imaging methodology was developed for use in CLIA-based clinical trials. Experimental Design: A series of ten normal and ten abnormal patient small bowel biopsies were manually evaluated by two pathologists to determine celiac disease (CD) state using the standard Marsh score. Two quantitative methods were developed—an automated stereological methodology was used to evaluate surface area on whole slide images and an image analysis complementary approach. Methods: Stereology line probes were used to count one-dimensional “hits” on points at the distal ends of the lines which exist over reference tissue area, and “cuts” through the two-dimensional range of the line as it passes through the epithelium of the reference tissue to background, or vice versa. Results: There was strong concordance between the pathologist scores, and the automated stereology analysis, with the automated approaches able to sufficiently delineate intermediate grades of disease, normally more difficult in visual assessments. Conclusion: The quantitative methodology is a valuable addition to CLIA-based clinical trials. Quantitation provides reproducible and unbiased endpoints that can evaluate both the morphological and immune response in therapeutic clinical studies.