parathyroid; tumor; HGF; TGFb1; IGF-ISerum levels of growth factors HGF, TGFbeta-1 and IGF-I in parathyroid tumors

INTRODUCTION: HGF (Hepatocyte Growth Factor), TGFb1 (Transforming Growth Factor b1) and IGF-I (Insulin Like Growth Factor I) are cytokines that are involved in the parathyroid tumors formation and growth. We tried to determine, if there are changes and relationships in the production of these cytokines by tumor cells of parathyroid tumors. MATERIAL AND METHODS: We determined concentrations of HGF, TGFb1 and IGF-I in serum from peripheral blood of 16 patients with parathyroid adenoma and of 8 patients with parathyroid secondary hyperplasia before and after parathyroidectomy. Results were compared with serum levels in healthy people. RESULTS: Both preoperative and postoperative HGF serum levels in patients with parathyroid adenoma and secondary hyperplasia are significantly higher than in healthy people. Preoperative and postoperative serum levels of TGFb1 in parathyroid adenoma and postoperative TGFb1 serum levels in parathyroid secondary hyperplasia are higher, compared with those in the healthy population and in parathyroid secondary hyperplasia preoperatively. There are no significant differences of IGF-I serum levels among the all investigated groups of patients. CONCLUSIONS: Changes in the growth factors production by parathyroid tumor cells are reflected by their concentrations in peripheral blood. The elevation of HGF serum levels in patients with parathyroid adenoma and hyperplasia can be explained by very high HGF production by tumor cells. Nevertheless, there is no decrease of HGF serum levels after the parathyroidectomy. That may be the result of the extratumoral production of this cytokine. Also TGFb1 and IGF-I serum levels indicate high possibility of the extratumoral production of these cytokines. Higher postoperative IGFI serum levels (but not significantly) in parathyroid secondary hyperplasia are in accordance with its bone production.