[Immunohistochemical analysis with anti-cytokeratin antibody in the prostatic epithelium]

We performed immunohistochemical studies of the prostatic epithelium using three different anti-cytokeratin monoclonal antibodies (35 beta-H11, RCK108, and 34 beta-E12), and also investigated the immunoreactivity of various prostatic lesions with basal cell specific anti-cytokeratin antibody (34 beta-E12).

One hundred and thirty one prostatic specimens were obtained at surgery or biopsy. H-E stained sections were available for review in all cases. They were classified according to histopathology; benign prostatic hyperplasia (BPH), prostatic cancer (PCA), atrophic acini, atypical adenomatous hyperplasia (AAH), and prostatic intraepithelial neoplasia (PIN). ABC or LSAB method was utilized for immunohistochemical staining with 3 anti-cytokeratin monoclonal antibodies.

35 beta-H11 was mainly stained in the luminal cells and RCK108 was stained both in the luminal and the basal cells in BPH. 35 beta-H11 showed highly positive staining in the prostatic cancer regardless of degree of differentiation. RCK108 tended to be less stained in the prostatic cancer cells with lower grades of tumor differentiation compared to those with higher grades. 34 beta-E12 was stained only in the basal cells, but neither in the normal luminal cells nor the cancer cells. Using 34 beta-E 12, basal cells were positively stained in most of the cases with BPH, while not in PCA. Atrophic acini and AAH was stained with 34 beta-E12 as positively as BPH. Basal cells were discontinuously or negatively stained in many cases with high-grade PIN.

The luminal cells in BPH were highly positively stained using 35 beta-H11 or RCK108. RCK108 tended to be less stained in the prostatic cancer cells with lower grades of tumor differentiation. Positive staining of 34 beta-E12 strongly suggested a benign lesion, therefore immunohistochemistry using this antibody would be useful as an aid for pathological diagnosis.