Endocrine Abstracts

Background: Primary hyperparathyroidism is one of the most common endocrine disorders caused by adenoma (80%), hyperplasia (15%) and carcinoma (5%). It is often difficult to differentiate between hyperplasia from an adenoma of a parathyroid gland. Accordingly, the aim of this study was to assess apoptotic index as a potentially useful in diagnosis.

Methods: Apoptotic cells was investigated in the parathyroid specimens of 21patients (4M, 17F, average age of 57 years) undertaken surgery due to primary hyperparathyroidism caused by adenoma, n=11, and primary hyperplasia, n=10 cases. For immunohistochemistry, frozen sections were incubated with murine monoclonal antihuman antibodies, anti-CD253 and anti-CD95. The dilution of the primary antibodies was verified in a series of pilot experiments. The immunohistological investigations were performed by the EnVision method with New Fuchsine Chromogen from DAKO. The number of apoptotic cells (apoptotic index) were counted and expressed as a mean value of at least six counted high power fields (HPF, ×400). The sections were counterstained with Mayer’s haematoxylin. The protocol was approved by the Institutional Ethics Committee.

Results: Unexpectedly, the apoptotic index was the highest in capillary endothelial vessels stained both with CD253 and CD95 in all cases. Only a few chief cells were positively stained with these antigens. There were no differences between adenoma and primary hyperplasia in the relation to number of apoptotic cells.

Conclusion: The results suggest that increased apoptotic capillary endothelial cells may be related to pathogenesis of hyperplasic state of the parathyroid glands.