An Automated Method for Counting Cytotoxic T-cells From CD8 Stained Images of Renal Biopsies

Studying inflammatory cell subsets in transplant biopsies can be important for diagnosis and to understand pathogenesis. Counting the different subsets of lymphocytes and macrophages in the immunostained renal biopsy is often considered as the only way to characterize the inflammatory infiltrate. Counting each subset of cells in each biopsy under a light microscope can be extremely tedious, time consuming and subject to inter- and intra-personal variability. This paper presents a new method to automatically count the number of CD8 positive cytotoxic t-cells on scanned images of immunostained slides of renal allograft biopsies. The method uses normalized multi-scale difference of Gaussian to detect the potential cytotoxic t-cell candidates regions, both in the color channel and the intensity channel. Then, it fuses the information from both channels' candidate regions to detect the individual cells within cell clumps. The evaluation of the proposed method shows that there is a strong consensus between the proposed method's markings with the pathologist's markings (94.4%).