Value and limitations of immunohistochemistry and gene sequencing for detection of the IDH1-R132H mutation in diffuse glioma biopsy specimens

J Neuropathol Exp Neurol. 2011 Aug;70(8):715-23. doi: 10.1097/NEN.0b013e31822713f0.


To assess the value of anti-isocitrate dehydrogenase 1 (IDH1) immunohistochemistry for evaluating diffuse gliomas, we analyzed anti-IDH1-R132H immunohistochemistry using monoclonal antibodies DIA-H09 and IMab-1 and IDH1 gene sequencing in formalin-fixed and paraffin-embedded biopsy samples of 95 diffuse gliomas. We found concordant immunostaining results using the 2 antibodies in 94 (98.9%) of the 95 cases, but DIA-H09 generally showed a higher signal-to-background ratio than IMab-1 did. Fifty-five percent of cases showed anti-IDH1-R132H immunostaining of virtually all tumor cells and 15% of only a fraction of tumor cells. All cases with complete or partial immunostaining of the tumor tissue carried the IDH1-R132H mutation. In all cases with negative immunostaining results (approximately 30%), genetic analysis showed IDH1 wild-type or non-R132H-IDH1 mutations. In a single tiny biopsy, both anti-IDH1-R132H antibodies showed immunoreactivity, but genetic testing was inconclusive. Our data confirm anti-IDH1-R132H immunostaining as a reliable method for evaluation of IDH1 gene mutation status. They also suggest the following: (i) in some cases, nonspecific background staining or regional heterogeneity of IDH1-R132H protein expression may necessitate confirmatory genetic analysis; (ii) for individual cases, anti-IDH1-R132H immunostaining may not reliably identify infiltrating tumor cells admixed with preexisting or reactive glial cells; and (iii) in tiny biopsies, immunohistochemistry may be more sensitive for detection of IDH1-R132H mutation than genetic analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arginine / genetics*
  • Biopsy
  • Brain Neoplasms / diagnosis*
  • Brain Neoplasms / genetics*
  • Genetic Testing
  • Glioma / diagnosis
  • Glioma / genetics*
  • Histidine / genetics*
  • Humans
  • Immunohistochemistry / methods
  • Isocitrate Dehydrogenase / genetics*
  • Mutation / genetics*
  • Reproducibility of Results
  • Sequence Analysis / methods


  • Histidine
  • Arginine
  • Isocitrate Dehydrogenase
  • IDH1 protein, human