Expression of PAX-5 in B Cell Hodgkin and Non Hodgkin Lymphoma

Abstract

Background: B-cell malignancies including Precursor B-cell lymphoblastic lymphoma/leukemia and Hodgkin Lymphoma show a wide spectrum of B-cell differentiation from early stage B-cell precursors to mature B-cells ending in terminal differentiation to plasma cells. Pan-B-cell antigens routinely used for the diagnosis of B-cell lymphoma, include CD19, CD20, CD22 and CD79a.PAX-5 protein, also known as B-cell-specific activation protein is a B-cell-specific transcription factor; essential for commitment and functional maintenance used in the diagnosis of B cell Hodgkin and non-Hodgkin lymphoma. PAX-5 show nuclear positivity in B cell lymphomas and moderate (dim) positivity in Hodgkinlymphoma Reed Sternberg cells make this marker ideal for diagnosing B cell malignances. Objective: To determine the expression of PAX-5 in B cell Hodgkin and non-Hodgkin Lymphoma in order to improve the diagnosis of B-cell lymphomas. Methods: In this Prospective study, all the cases of B cell lymphoma diagnosed at The Aga Khan University Hospital, Karachi from July 2010 to July 2011were included. A panel of Immunohistochemical stain was performed in all cases along with additional PAX- 5 stain with appropriate controls. Results: Total 125 cases were included. Hodgkin Lymphoma (Mixed cellularity) was the commonest B-cell lymphoma subtype, 32 (25%) cases. Other common subtypes included Hodgkin lymphoma (Nodular sclerosis subtype), diffuse large B-cell lymphoma and B lymphoblastic lymphoma. Conclusion: This study demonstrates that PAX-5 is the most sensitive and reliable immuhohistochemicalmarker in the diagnosis of B cell Hodgkin and non-Hodgkin lymphoma.

CD15, CD30, and PAX5 evaluation in Hodgkin's lymphoma on fine‐needle aspiration cytology samples

“…Despite the typical or variable background, the identification of diagnostic HCs and RSCs is mandatory for the diagnosis of HL on fine-needle aspiration cytology (FNAC). [18][19][20][21][22] On FNAC samples, CD30 and CD15 can be successfully applied, while PAX5 has been rarely reported. Moreover, the diagnostic cells may be partially hidden by the HL background or may be confused with histiocytes, immunoblasts or other cells.…”

“…The immunophenotypical profile of HC and RSC is routinely achieved by CD15 (Leu-M1), CD30 (Ki-1), and PAX5 positivity on histological samples. [18][19][20][21][22] On FNAC samples, CD30 and CD15 can be successfully applied, while PAX5 has been rarely reported. 2 Cytological and immunocytochemical identification of HC and RSC may be hampered by their small number on FNAC samples and by problems related to the technical supports used for different ancillary techniques, namely smears, cytospins, liquid-based preparation, cell-blocks (CB), and FTA cards.…”

“…Diagnostic cells may lose the cytoplasm, may show atypical features or may look like histiocytes or immunoblasts 8,13,17. Antibodies generally used to identify HC and RSC are CD15 (Leu-M1), CD30 (Ki-1), and Pax-5 18,[20][21][22]1.…”

“…HCs and RSCs are "crippled" B-cells in origin that cannot produce immunoglobulin but are able to escape apoptosis and to produce a number of inflammatory mediators that determine the constitution of the specific cell background and fibrosis 1. Antibodies generally used to identify HC and RSC are CD15 (Leu-M1), CD30 (Ki-1), and Pax-5 18,[20][21][22]22 ; its expression pattern may be paranuclear (corresponding to the Golgi region), diffuse cytoplasmic, and/or prevalent on the cell membrane.…”

New biomarkers and therapeutic strategies in acute lymphoblastic leukemias: Recent advances

“…CD19 displays several functions: Src family amplification, expansion of mitogen‐activated protein kinase (MAPK), and, as major consequence, the promotion of cell proliferation . CD19 is known as the “pan‐B antigen,” and its absence rules out the diagnosis of B‐cells malignancies . The CD19 antigen precedes the expression of CD10, CD20, and other B‐specific antigens.…”