HGF (Hepatocyte Growth Factor) and TGFβ1 (Transforming Growth Factor β1) are cytokines that are involved in the formation and growth parathyroid and thyroid tumors. We tried to determine, whether there are changes and relationships in the production of these cytokines by tumor cells of the parathyroid as compared to the thyroid tumors.We determined concentrations of HGF and TGFβ1 in sera from peripheral blood of 28 patients with thyroid cancer (14 adenomas, 14 papillary carcinomas) and of 16 patients with parathyroid adenoma and of 8 patients with parathyroid hyperplasia. The results were compared with the sera levels of healthy people. The levels of HGF in the sera of patients with parathyroid adenoma and hyperplasia are significantly higher as compared to healthy controls (adenoma 1551 ± 592, hyperplasia 2718 ± 1383, controls 652 ± 154 pg/mL).We found significantly higher concentrations of HGF in the sera of patients with thyroid adenoma and papillary carcinoma as compared to healthy controls (adenoma 29.74 ± 12.74, hyperplasia 14.81 ± 4.98, controls 13.64 ± 5.83 pg/mL). Also the increase in the post-surgery levels of TGFβ1 in parathyroid hyperplasia (28.82 ± 11.84, controls 13.64 ± 5.83 pg/mL), although of no statistical significance, seems to be interesting. The concentrations of TGFβ1 in the sera of patients with thyroid nodal goiter and papillary carcinoma did not show any significant differences (adenoma 35.87 ± 10.87, carcinoma 37.73 ± 12.99, controls 28.98 ± 20.02 pg/mL). The changes in the growth factor production by parathyroid and thyroid tumor cells are reflected by their concentrations in peripheral blood. The elevation of HGF sera levels in patients with parathyroid adenoma or hyperplasia and in thyroid tumors can be explained by very high production of HGF by tumor cells. Contradictory to that is the fact, that after the parathyroid surgery no decrease of HGF in sera was observed. These results are in favor of an extra-tumor production of this cytokine.

        Key words: parathyroid, thyroid, tumor, HGF, TGFβ1.