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Journal of Endocrinological Investigation

, Volume 27, Issue 7, pp 636–642 | Cite as

Failure to use measurement of megalin secretory components complexed with serum thyroglobulin as a tool to identify metastases after surgery in papillary thyroid cancer

  • S. Lisi
  • F. Menconi
  • M. A. Altea
  • L. Agate
  • E. Molinaro
  • M. G. Castagna
  • D. Taddei
  • L. Grasso
  • A. Pinchera
  • R. Elisei
  • M. Marinò
Original Article

Abstract

When thyroid follicles are intact, some colloidal thyroglobulin (Tg) reaches the circulation by megalin-mediated transcytosis and is to various extents complexed with megalin secretory components. In contrast, in papillary thyroid cancer (PTC), serum Tg is not complexed with megalin because it is directly secreted by tumor cells. Here we attempted to use measurement of megalin secretory components to distinguish PTC patients with thyroid remnant plus metastases from those with thyroid remnant only, after thyroidectomy and before 131I ablation. Tg values in anti-Tg antibodies (TgAb)-free sera from 5 PTC patients with thyroid remnant plus metastases and 12 PTC patients with thyroid remnant only were measured following pre-adsorption with uncoupled protein A beads or with protein A beads coupled with antimegalin antibodies. The degree of Tg pre-adsorption with antimegalin antibodies was minimal, with no substantial differences between the two groups. Thus, we concluded that measurement of megalin secretory components is unlikely to be useful to identify the origin of serum Tg in PTC patients after thyroidectomy.

Key-words

Thyroglobulin thyroid megalin cancer transcytosis 

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Copyright information

© Italian Society of Endocrinology (SIE) 2004

Authors and Affiliations

  • S. Lisi
    • 1
  • F. Menconi
    • 1
  • M. A. Altea
    • 1
  • L. Agate
    • 1
  • E. Molinaro
    • 1
  • M. G. Castagna
    • 1
  • D. Taddei
    • 1
  • L. Grasso
    • 1
  • A. Pinchera
    • 1
  • R. Elisei
    • 1
  • M. Marinò
    • 1
  1. 1.Department of EndocrinologyUniversity of PisaPisaItaly

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