Oppenheim D S, Kana A R, Sangha J S, Klibanski A
Neuroendocrine Unit, Massachusetts General Hospital, Boston 02114.
J Clin Endocrinol Metab. 1990 Apr;70(4):859-64. doi: 10.1210/jcem-70-4-859.
Hypersecretion of the pituitary glycoprotein hormone alpha-subunit has been reported in pituitary adenomas, particularly in clinically nonfunctioning tumors and somatotroph adenomas. However, the prevalence of such hypersecretion has not been precisely defined. Using both a new highly sensitive and specific monoclonal antibody assay and a polyclonal antibody assay, serum levels of free alpha-subunit were compared in 63 unselected patients with these tumors, 19 patients with acromegaly, and 95 normal controls. In all patients the monoclonal assay detected a significantly greater number of subjects with elevated alpha-subunit levels than did the polyclonal assay (21 vs. 14; P less than 0.01). Fourteen of the 63 patients with clinically nonfunctioning tumors (22%) had elevated serum alpha-subunit levels in the monoclonal assay vs. 11 (17%) in the polyclonal assay. Among the 19 patients with acromegaly, the prevalence was 7 (37%) and 3 (16%) using the monoclonal and polyclonal assays, respectively. Twenty-eight (44%) of the patients with clinically nonfunctioning pituitary adenomas were female. Eleven (39%) of the women were under 45 yr old, as were 10 (29%) of the men. We conclude that the prevalence of free alpha-subunit hypersecretion in patients with clinically nonfunctioning and somatotroph adenomas may be higher than previously recognized, and that a sensitive and specific monoclonal antibody free alpha-subunit assay may provide a useful tumor marker in these patients. The prevalence of clinically nonfunctioning pituitary tumors among younger men and women may also have been previously under-estimated.
垂体腺瘤中曾有垂体糖蛋白激素α亚基分泌过多的报道，尤其是在临床无功能性肿瘤和生长激素腺瘤中。然而，这种分泌过多的发生率尚未得到精确界定。采用一种新型高灵敏度和特异性的单克隆抗体检测法以及一种多克隆抗体检测法，对63例未经挑选的此类肿瘤患者、19例肢端肥大症患者和95名正常对照者的血清游离α亚基水平进行了比较。在所有患者中，单克隆检测法检测出α亚基水平升高的受试者数量显著多于多克隆检测法（21例对14例；P<0.01）。63例临床无功能性肿瘤患者中，有14例（22%）在单克隆检测法中血清α亚基水平升高，而在多克隆检测法中有11例（17%）升高。在19例肢端肥大症患者中，单克隆检测法和多克隆检测法的发生率分别为7例（37%）和3例（16%）。临床无功能性垂体腺瘤患者中有28例（44%）为女性。其中11例（39%）女性年龄在45岁以下，男性有10例（29%）。我们得出结论，临床无功能性和生长激素腺瘤患者中游离α亚基分泌过多的发生率可能高于此前的认识，并且一种灵敏且特异的单克隆抗体游离α亚基检测法可能为这些患者提供一种有用的肿瘤标志物。年轻男性和女性中临床无功能性垂体肿瘤的发生率此前可能也被低估了。
