Immunohistochemical analysis of iris biopsy specimens from patients with Fuchs' heterochromic cyclitis.

Using immunohistochemical techniques, we analyzed iris biopsy specimens from eight patients with Fuchs' heterochromic cyclitis, seven patients with various other types of uveitis, and eight glaucoma patients without uveitis. No specific abnormalities related to Fuchs' heterochromic cyclitis could be detected. Four of the patients with Fuchs' heterochromic cyclitis and four of the patients with uveitis showed evidence of an inflammatory cell infiltrate, which was a mixture of interleukin-2 receptor-negative T helper and suppressor cells, B lymphocytes, and plasma cells. Only an occasional T lymphocyte could be seen in two of the patients without uveitis. The class II antigen HLA-DR was expressed on iris stromal cells in every patient in the Fuchs' heterochromic cyclitis group and uveitis group and in six of the patients in the nonuveitis group. In six of the Fuchs' heterochromic cyclitis patients, including two without immunohistochemical evidence of inflammatory cell infiltrate, histologic abnormalities were present on hematoxylin and eosin sections.

Variation of prostate-specific antigen expression in different tumour growth patterns present in prostatectomy specimens.

A series of 55 randomly chosen radical prostatectomy specimens was analyzed for expression of prostate-specific antigen (PSA) by immunohistochemical techniques. Tissue sections were selected in such a manner that in addition to glandular benign prostatic hyperplasia (BPH), one or more different prostatic tumour growth patterns were present. Four monoclonal antibodies, directed against three different PSA epitopes, and one polyclonal anti-PSA antiserum were used. Expression of PSA was compared with that of prostate-specific acid phosphatase (PAP), recognized by two different polyclonal antisera. A critical dilution aimed at a maximum of staining intensity on BPH tissue sections was chosen for all antibodies. Anti-PSA and anti-PAP antisera stained essentially all BPH samples (over 90%). Irrespective of the nature of the antibodies used, PSA expression was found to be decreased in prostatic carcinoma. A clear cut relationship was found between immunoreactivity for PSA and the degree of differentiation of the tumour area. Under the experimental conditions used the PSA monoclonal antibodies stained only 1 out of 10 undifferentiated carcinomas, whereas 50% to 70% of the well- and moderately-differentiated carcinomas showed immunoreactivity. This correlation was less pronounced with the PAP staining pattern. If the PSA antibody titer was raised the percentage of clearly staining undifferentiated carcinomas could be considerably increased (up to 60%-100%), indicating that PSA expression is not absent, but lowered in most (if not all) undifferentiated carcinomas.

Monoclonal antibody Ki-67 defined growth fraction in benign prostatic hyperplasia and prostatic cancer.

Growth fractions were assessed immunohistochemically in prostatic tissues with benign glandular hyperplasia (BPH) and in specimens of prostatic cancer using the monoclonal antibody Ki-67. This antibody is specific for a proliferation-associated nuclear antigen. In BPH tissues about 0.3% of nuclei of epithelial cells was reactive with Ki-67. The Ki-67 positive nuclei were distributed equally among the basal and luminal cells of the hyperplastic prostatic acini. In prostatic cancer the Ki-67 defined growth fraction ranged from 0.4% to 9.1% (mean value 2.9%). Cancers with a cribriform growth pattern and tumors composed of solid areas of undifferentiated cancer cells showed the highest growth fraction (average values 4.0%, respectively 7.6%). The investigated four tumors composed of undifferentiated solitary tumor cells with diffuse infiltration of the stroma demonstrated an unexpectedly low growth activity (average 1.2%). In cancers with a glandular growth pattern the Ki-67 defined growth fraction of tumor cells varied from 2.2% to 5%. Compared with other epithelial tumors these values are low, but they are in agreement with the earlier findings on prostatic cancer obtained with 3H-thymidine labeling and bromodeoxyuridine incorporation. The observed variation in the level of Ki-67 defined growth activity partly related to the histological tumor pattern suggests that Ki-67 labeling may serve as a prognostic factor additional to the current histopathological grading criteria of prostatic cancer.