INCREASED PLASMA-CONCENTRATION OF EPIDERMAL GROWTH-FACTOR IN FEMALE-PATIENTS WITH NONTOXIC NODULAR GOITER

Objective: Epidermal growth factor (EGF) is believed to be one of the most potent growth factors for the thyroid gland. Design and methods: We tested plasma EGF concentrations (radioreceptor method) in patients with nontoxic nodular goitre (NNG). Blood samples from patients with NNG were collected on the day before the surgery, during subtotal thyr oidectomy (sTx) - from peripheral and thyroid veins, on the 3rd day af ter sTx, 3 months after sTx, and 9 months after the surgery. Results: Before the operation, the mean plasma EGF concentration in 50 women wi th NNG was significantly higher (1.16 +/- 0.69 ng/ml: mean +/- S.E.) t han that in 32 control female patients subjected subsequently to other (non-thyroid) operations (0.41 +/- 0.27 ng/ml; P < 0.001), and that i n 20 healthy women (0.35 +/- 0.11 ng/ml: P < 0.001), both of which gro ups were without goitre or had a small non-toxic diffuse goitre. The s urgical treatment of NNG resulted in a significant reduction in plasma EGF 3 months after sTx (0.56 +/- 0.22 ng/ml). A further slight decrea se was observed 9 months after sTx (0.44 +/- 0.14 ng/ml). Conclusions: Our observations confirm the assumption that EGF may participate in t he process of goitre formation in human subjects. However. the source of EGF involved in this process remains unclear. Some findings could s uggest that plasma EGF, which was increased in patients with NNG, map be of non-thyroid origin: however, the majority of our observations st rongly stress the significance of an intact thyroid in the preservatio n of an unchanged EGF value, suggesting a role of locally produced EGF in the pathogenesis of NNG.