PAX8 and PAX5 are differentially expressed in B-cell and T-cell lymphomas.

Abstract

AIMS:

  The purpose of this study was to evaluate the expression patterns of B-cell specific activator protein (BSAP)/PAX5 and PAX8 in a wide variety of B-cell and T-cell neoplasms.

METHODS AND RESULTS:

  A wide range of B-cell and T-cell neoplasms were subjected to immunohistochemical staining with antibodies against BSAP/PAX5 and PAX8 (polyclonal, pPAX8; monoclonal, mPAX8). Ten non-neoplastic lymph node specimens were examined with the same panel. All of the tested neoplastic and non-neoplastic B-cells reacted with the BSAP/PAX5 and pPAX8 antibodies, but did not show reactivity with the mPAX8 antibody. All tested T-cell neoplasms were negative using the BSAP/PAX5, pPAX8 and mPAX8 antibodies.

CONCLUSIONS:

  This is the first study to show the absence of reactivity to an mPAX8 antibody in an expanded panel of B-cell lymphomas as well as in a variety of T-cell neoplasms. In contrast to the mPAX8 antibody, the pPAX8 antibody shows nuclear positivity in non-neoplastic B cells and mature B-cell neoplasms; however, this expression is probably a result of cross-reactivity with PAX5. Given that many laboratories use the pPAX8 antibody, a clear understanding of the differential staining patterns is necessary. The differential diagnosis of a B-cell lymphoma should be entertained when a pPAX8-positive, epithelial marker-negative neoplasm of uncertain primary origin is encountered.

• Authors: Elizabeth A Morgan, Olga Pozdnyakova, Alessandra F Nascimento, Michelle S Hirsch
• Journal: Histopathology (Histopathology) Vol. 62 Issue 3 Pg. 406-13 (Feb 2013) ISSN: 1365-2559 [Electronic] England
• PMID: 23163626 (Publication Type: Journal Article)
• Copyright: © 2012 Blackwell Publishing Ltd.

Chemical References

• Biomarkers, Tumor
• PAX5 Transcription Factor
• PAX5 protein, human
• PAX8 Transcription Factor
• PAX8 protein, human
• Paired Box Transcription Factors

Topics

• Biomarkers, Tumor (analysis)
• Humans
• Immunohistochemistry
• Lymphoma, B-Cell (diagnosis, metabolism)
• Lymphoma, T-Cell (diagnosis, metabolism)
• PAX5 Transcription Factor (analysis, biosynthesis)
• PAX8 Transcription Factor
• Paired Box Transcription Factors (analysis, biosynthesis)