Expression of vascular endothelial growth factor (VEGF) and VEGF receptor-1 (Flt-1) in Graves disease possibly correlated with increased vascular density

To evaluate the relation between hypervascularization and vascular endothel ial growth factor (VEGF) in the thyroid glands of patients with Graves dise ase, 19 Graves disease tissues and 6 normal thyroid tissues were studied by immunohistochemistry, in situ hybridization (ISH), and reverse transcripta se-polymerase chain reaction. The mean microvascular densities per follicle and per millimeter of the thyroid follicles' circumferential length in the Graves disease tissues (mean 3.37 and 13.91) were significantly higher tha n those in the normal thyroid tissues (mean 2.15 and 7.28) (tied P = .0005, P = .0185, and P < .05, respectively). An antibody against VEGF markedly r eacted with hyperplastic follicular cells in Graves disease. The intensity was especially strong in the cells covering papillary growth regions contai ning accumulated microvessels. By ISH, VEGF messenger RNA (mRNA) signals we re also detected in the hyperplastic follicular cells in Graves disease tis sues and were especially strong in papillary growth regions. The VEGF recep tor-1 (Flt-1) protein and mRNA were observed in endothelial cells of all Cr aves disease tissues. These findings suggest that hypervascularity in Grave s disease tissues is related to upregulated VEGF expression in hyperplastic follicles. Copyright (C) 2001 by W.B. Saunders Company