Accurate Quantitation of Ki67-positive Proliferating Hepatocytes in RabbitLiver by a Multicolor Immunohistochemical (IHC) Approach Analyzed with Automated Tissueand Cell Segmentation Software

摘要

Determination of hepatocyte proliferation activity is hampered by the presence ofKi67-positive non-parenchymal cells. We validated a multicolor immunohistochemical approach using multispectral tissue and cell segmentation software. Portal vein branchesto the cranial liver lobes of 10 rabbits were embolized, leading to atrophy of the craniallobes and hyperplasia of the caudal lobes. Slides from cranial and caudal lobes were double-stained and triple-stained. The Ki67 proliferation index was calculated using automatedtissue and cell segmentation software and compared with manual counting by two independentobservers. A substantial variation was seen in the number of Ki67-positive hepatocytes inthe different specimens in both double and triple staining . Correlationcoefficients between manual counting and the digital analysis were 0.76 for observer 1 and 0.78 for observer 2 withdouble staining and R ~(2) = 0.91 for observer 1 and R ~(2) = 0.89 for observer 2, p <0.001 withtriple staining. In conclusion, in rabbit, the hepatocellular proliferation index can bereliably determined using automated tissue and cell segmentation software in combinationwith IHC multiple staining. Our findings may be useful in clinical practice when Ki67proliferation index yields prognostic significance.