Chemistry
Thyroid related
Thyroid stimulating hormone receptor antibody

Author: Nat Pernick, M.D. (see Authors page)

Revised: 23 February 2016, last major update March 2011

Copyright: (c) 2002-2016, PathologyOutlines.com, Inc.

PubMed Search: Thyroid stimulating hormone receptor antibody [title]
Definition / General
  • Also called TRAb (TSH Receptor Antibody)
  • Previously called thyroid stimulating immunoglobulin or long acting thyroid stimulators (LATS)
  • Present in 85 - 95% with Graves disease
  • Either stimulating (causing hyperthyroidism), blocking (usually no clinical impact) or no effect
  • Antibodies cross placenta and may cause thyroid dysfunction in newborns
Laboratory
Indications
  • Not for routine clinical testing
  • To confirm Graves disease in difficult cases, monitor hormone replacement therapy, diagnose neonatal thyrotoxicosis

Methodology
  • Thyrotropin binding inhibiting immunoglobulin technique, RIA

Reference ranges
  • Negative: 0 - 9%
  • Indeterminate: 10 - 15%
  • Positive: 16% or more
Interpretation
  • Positive results are consistent with autoimmune disease
  • Low antibody titer before drug therapy for Graves disease is a good prognostic factor for remission after drug therapy (Horm Metab Res 2004;36:92) or relapse (Horm Metab Res 2007;39:56), predicts risk of thyroid dysfunction in newborns of mothers with Graves disease
Additional References