Immunohistochemical finding of alpha-1-antichymotrypsin in tissues of benign prostatic hyperplasia and prostate cancer.
BACKGROUND
Ratio of free to total (F/T) prostate-specific antigen (PSA) is higher in the blood of patients with benign prostatic hyperplasia than those with prostate cancer. To clarify the difference between ratios in these two, alpha-1-antichymotrypsin, the major component of the bound PSA in the blood, was immunohistochemically examined.


METHODS
Tissues were obtained surgically via a retropubic approach from patients with benign prostatic hyperplasia (nine cases) and prostate cancer (27 cases). These samples were processed in paraffin blocks, cut into 5 mm sections and stained with antibodies against alpha-1-antichymotrypsin and PSA.


RESULTS
The percentage of alpha-1-antichymotrypsin-stained cells in prostate cancer was higher than that in benign prostatic hyperplasia (P<0.05). Almost all of glandular and cancer cells were stained with PSA antibody. The percentage of alpha-1-antichymotrypsin-stained cells in prostate cancer did not correlate to histologic grade, although alpha-1-antichymotrypsin-stained cells were more widely scattered in high grade tissues. No correlation was found between alpha-1-antichymotrypsin-stained cells and ratio of F/T in the blood of cancer patients. In about 20% of cancer tissues, histiocytes with positive alpha-1-antichymotrypsin staining were found in stroma but not in that of benign prostatic hyperplasia.


CONCLUSIONS
Prostate cancer tissues are shown to have a richer environment of alpha-1-antichymotrypsin than those of benign prostatic hyperplasia. Some cancer tissues contained alpha-1-antichymotrypsin-stained histiocytes. These local events may correlate to a high amount of the bound form among total PSA in the blood of prostate cancer patients.
Tanaka
M
M
Department of Urology, Asahi General Hospital, Chiba, Japan. aghp1326@a1.mbn.or.jp
Suzuki
Y
Y
Takaoka
K
K
Murakami
S
S
Suzuki
N
N
Shimazaki
J
J
D000368:Aged; D006644:Histiocytes / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood / Q000378:metabolism; D011470:Prostatic Hyperplasia / Q000378:metabolism* / Q000473:pathology; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D014018:Tissue Distribution; D000514:alpha 1-Antichymotrypsin / Q000378:metabolism*
D000514:alpha 1-Antichymotrypsin; D017430:Prostate-Specific Antigen