Computer-assisted quantitative analysis of Ki-67 antigen in dysplasia--associated lesions or masses in ulcerative colitis.
OBJECTIVE
The aim of this study was to apply computer-assisted methodology in assessment of Ki-67 positivity in "adenoma-like" dysplasia associated lesions or masses (DALMs), and carcinoma in ulcerative colitis (UC), and to determine a new approach to grading of Ki-67 staining intensity.


METHODS
Immunohistochemical slides were quantitatively analyzed for estimation of proportion and intensity of Ki-67 positive-stained cells in a total of 50 "adenoma-like" DALMs (27 with low-grade dysplasia and 23 with high-grade dysplasia), and 17 adenocarcinomas associated with UC. The four grades of immunohistochemical staining intensity were established by an automated classification of nuclear optical densities.


RESULTS
The Ki-67 labeling index (LI) in low-grade dysplasia was significantly lower than in high-grade dysplasia, and carcinoma (p < 0.001). The Ki-67 LI of carcinomas was not significantly different from the value obtained in high-grade dysplasia (p > 0.05), however having the difference in percentage values of the moderate stained nuclei (p < 0.05). The overall average values of chromogene nuclear optical density, showed statistically significant differences between DALMs and carcinoma (p < 0.05), although not between normal mucosa and low-grade dysplasia (p > 0.05).


CONCLUSIONS
The obtained results imply, according to the overall percentage of labeled nuclei, that high-grade dysplasia is very close to carcinoma, while there is the difference in the percentage of moderately stained nuclei. We showed that Ki-67 positivity have a different internal distribution which could be useful in analysing these lesions. These findings also, indicate the important biological differences between low-grade dysplasia and carcinoma in UC, and a low proliferative potential of the former. Automated image analysis permits an objective [corrected] estimation of Ki-67 immunohistochemical staining in UC-associated dysplasia and carcinoma.
School of Medicine Nis, Institute of Pathology, Nis, Serbia. vekivz@eunet.yu
Vesna
V
Zivković
Aleksandar
A
Petrović
Biljana
B
Dordević
Vuka
V
Katić
Jasmina
J
Gligorijević
Voja
V
Pavlović
Miljan
M
Krstić
D000328:Adult; D000368:Aged; D003093:Colitis, Ulcerative / Q000276:immunology* / Q000473:pathology; D015179:Colorectal Neoplasms / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007150:Immunohistochemistry; D007413:Intestinal Mucosa / Q000276:immunology / Q000473:pathology; D007417:Intestinal Polyps / Q000276:immunology / Q000473:pathology; D019394:Ki-67 Antigen / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D011230:Precancerous Conditions / Q000276:immunology* / Q000473:pathology
D019394:Ki-67 Antigen