Sanno N, Teramoto A, Sugiyama M, Itoh Y, Osamura R Y
Department of Pathology, Tokai University School of Medicine, Kanagawa, Japan.
Am J Clin Pathol. 1996 Jul;106(1):16-21. doi: 10.1093/ajcp/106.1.16.
Pituitary adenomas that are characterized by the absence of a particular clinical syndrome and the absence of excessive hormone secretion have been classified as nonfunctioning adenomas. Recent development of immunohistochemical analysis and hormonal assay have suggested that many of these tumors have function to secret the gonadotropin subunits. A novel procedure biotin amplification in immunohistochemistry, catalyzed signal amplification (CSA) has been reported recently. In this study, the authors applied this new method to tissues from 50 cases of clinically nonfunctioning adenomas. These cases had no evidence of endocrinological signs by hormone secretion. When the CSA system was applied in normal pituitary gland, each of subunits was positive even when the antibody was diluted 1:1,000,000, which is 1,000 folds of standard indirect immunoperoxidase method. Immunohistochemical staining by indirect immunohistochemical method revealed that all 50 adenomas were negative for all the anterior hormones, including growth hormone (GH), prolactin (PRL), adrenocorticotropic hormone (ACTH), beta-subunit of luteinizing hormone (LH beta), follicle-stimulating hormone (FSH beta), thyroid stimulating hormone (TSH beta), and a-subunit of glycoprotein (alpha SU). Using avidin-biotin complex (ABC) method, two cases were positive for FSH beta and four cases were positive for alpha SU, respectively, and the immunopositivities were observed weakly in scattered cells. By CSA system, 26 cases of 50 nonfunctioning adenoma were positive for FSH beta, 16 cases were positive for LH beta, and 29 cases were positive for alpha SU, respectively. The immunoreactivities were clearly observed in cytoplasm of many adenoma cells. This amplification procedure provides a means of greatly increasing the sensitivity of the immunohistochemistry including subunits of glycoproteins that are difficult to detect by previous indirect immunoperoxidase method or ABC method. This amplification procedure provides a great increase in the sensitivity of the immunohistochemistry for the detection of gonadotropin subunits and suggest that significant proportion of the nonfunctioning adenomas are gonadotropin subunit producing adenomas.
缺乏特定临床综合征且无激素分泌过多表现的垂体腺瘤被归类为无功能腺瘤。免疫组织化学分析和激素检测的最新进展表明，这些肿瘤中有许多具有分泌促性腺激素亚基的功能。最近报道了一种免疫组织化学中的新方法——生物素扩增，即催化信号放大（CSA）。在本研究中，作者将这种新方法应用于50例临床无功能腺瘤的组织。这些病例没有激素分泌导致的内分泌体征证据。当CSA系统应用于正常垂体时，即使抗体稀释至1:1,000,000（比标准间接免疫过氧化物酶法高1000倍），每个亚基仍呈阳性。间接免疫组织化学方法的免疫组织化学染色显示，所有50例腺瘤对所有前叶激素均为阴性，包括生长激素（GH）、催乳素（PRL）、促肾上腺皮质激素（ACTH）、黄体生成素β亚基（LHβ）、卵泡刺激素（FSHβ）、促甲状腺激素（TSHβ）和糖蛋白α亚基（αSU）。采用抗生物素蛋白-生物素复合物（ABC）法时，分别有2例FSHβ阳性和4例αSU阳性，免疫阳性在散在细胞中呈弱阳性。通过CSA系统，50例无功能腺瘤中有26例FSHβ阳性，16例LHβ阳性，29例αSU阳性。在许多腺瘤细胞的细胞质中可清晰观察到免疫反应性。这种放大程序提供了一种极大提高免疫组织化学敏感性的方法，包括检测以前用间接免疫过氧化物酶法或ABC法难以检测的糖蛋白亚基。这种放大程序极大提高了检测促性腺激素亚基的免疫组织化学敏感性，并表明相当一部分无功能腺瘤是产生促性腺激素亚基的腺瘤。
