[Value of alpha subunit assay in pituitary pathology].
We evaluated serum alpha-subunit concentrations in 72 patients bearing pituitary adenomas. We conclude that: 1) alpha-subunit hypersecretion is found in all patients with TSH secreting pituitary adenoma (n = 10). Two patients have a predominant secretion of alpha-subunit as compared to TSH secretion. 2) As concerns gonadotropin secreting pituitary adenomas (n = 3), all patient have elevated serum alpha-subunit levels with increased FSH and LT concentrations in 2 cases and 1 case respectively. 3) In prolactinomas (n = 14), alpha-subunit concentrations are not significantly different from that of normal subjects. 4) In 11 acromegalic patients, alpha-subunit hypersecretion is found in 2 patients only with GH-alpha and GH-PRL-alpha secreting pituitary adenomas. 5) Among 34 patients with nonsecreting adenomas, 8 have elevated alpha-subunit concentrations (24%). Positive immunocytochemical staining is found in 70% most often with gonadotropins (55%). Only a few pituitary tumors with positive alpha-subunit immunocytochemical staining have elevated serum alpha-subunit levels. At least, the measurement of basal circulating alpha-subunit levels is very useful in the follow-up of patients with nonsecreting adenomas. In our study, medical treatments including bromocriptine and somatostatin analogues have been found effective in patients with alpha-subunit hypersecretion. Further investigations are necessary to prove if such treatments could control tumoral growth and could prevent recurrences.
Morange
I
I
Service d'Endocrinologie, CHU Nord, Marseille.
Figarella-Branger
D
D
Gunz
G
G
Brue
T
T
Jaquet
P
P
D000172:Acromegaly / Q000097:blood; D000236:Adenoma / Q000097:blood* / Q000188:drug therapy / Q000378:metabolism; D000328:Adult; D000368:Aged; D001971:Bromocriptine / Q000627:therapeutic use; D005260:Female; D015292:Glycoprotein Hormones, alpha Subunit / Q000097:blood*; D006065:Gonadotropins, Pituitary / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use; D010911:Pituitary Neoplasms / Q000097:blood* / Q000188:drug therapy / Q000378:metabolism; D015175:Prolactinoma / Q000097:blood / Q000378:metabolism
D015292:Glycoprotein Hormones, alpha Subunit; D006065:Gonadotropins, Pituitary; D001971:Bromocriptine; D015282:Octreotide
Intérêt du dosage de la sous-unité alpha en pathologie hypophysaire.