Expression of the alpha- and beta-subunits of human chorionic gonadotropin by subsets of parathyroid cells in states of hyperparathyroidism.

Abstract

The alpha-subunit of human chorionic gonadotropin (hCG-alpha) has previously been found to be expressed in hyperplasias and tumours of numerous endocrine tissues including all those involved in MEN-I syndrome except the parathyroid glands. In the present immunohistochemical investigation of 86 patients with various states of hyperparathyroidism, expression of hCG-alpha by subsets of parathyroid cells was shown in 46 cases (54 per cent) including all states of hyperparathyroidism investigated: primary adenoma (n = 34, 44 per cent); uraemic secondary hyperplasia (n = 34, 53 per cent); MEN-I (n = 13, 77 per cent); MEN-II (n = 2, 100 per cent); and parathyroid carcinoma (n = 3, 100 per cent). Although the number of parathyroid cells expressing hCG-alpha was in general low, the occurrence of numerous immunoreactive cells appeared to be concentrated in primary adenoma and MEN-I (20 and 33 per cent of positive cases, respectively). No expression was found in ten normal control glands, except for very rare cells in one case. Expression of hCG-alpha was in part associated with that of hCG-beta, which appeared to be more commonly expressed than hCG-alpha in cases of secondary hyperparathyroidism. In separate experiments, Bouin fixation was found to preserve the immunoreactivity of hCG-alpha and hCG-beta better than the formalin fixation used in this study, suggesting that the figures may be underestimates. These immunohistochemical results are in agreement with a previous biochemical study showing hCG-alpha and hCG-beta in extracts of parathyroid tumours and extend to the parathyroid glands the otherwise ubiquitous finding of hCG-alpha expression in MEN-I-related neoplasms.

• Authors: G Carlinfante, R Lampugnani, C Azzoni, M R Aprile, M L Brandi, C Bordi
• Journal: The Journal of pathology (J Pathol) Vol. 185 Issue 4 Pg. 389-93 (Aug 1998) ISSN: 0022-3417 [Print] England
• PMID: 9828837 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Chorionic Gonadotropin, beta Subunit, Human
• Glycoprotein Hormones, alpha Subunit
• Neoplasm Proteins

Topics

• Adenoma (metabolism)
• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Chorionic Gonadotropin, beta Subunit, Human (metabolism)
• Female
• Glycoprotein Hormones, alpha Subunit (metabolism)
• Humans
• Hyperparathyroidism (metabolism, pathology)
• Hyperparathyroidism, Secondary (metabolism)
• Immunoenzyme Techniques
• Male
• Middle Aged
• Multiple Endocrine Neoplasia (metabolism)
• Neoplasm Proteins (metabolism)
• Parathyroid Glands (metabolism)
• Parathyroid Neoplasms (metabolism)
• Retrospective Studies
• Uremia (metabolism)