Loss of CD19 expression in B-cell neoplasms
Article first published online: 21 DEC 2005
Volume 48, Issue 3, pages 239–246, February 2006
How to Cite
Masir, N., Marafioti, T., Jones, M., Natkunam, Y., Rüdiger, T., Hansmann, M.-L. and Mason, D. Y. (2006), Loss of CD19 expression in B-cell neoplasms. Histopathology, 48: 239–246. doi: 10.1111/j.1365-2559.2005.02317.x
- Issue published online: 21 DEC 2005
- Article first published online: 21 DEC 2005
- Date of submission 29 March 2005 Accepted for publication 29 April 2005
- B-cell neoplasms;
Aims : To investigate whether an antibody against an intracellular epitope can detect CD19 in routine biopsy specimens and thus to document in detail its expression in human lymphomas.
Method and results : A polyclonal antibody to the C terminus of CD19 was used to immunostain paraffin-embedded samples of normal and neoplastic lymphoid tissues. CD19 was widely expressed in normal B cells and in extramedullary plasma cells. It was found in most B-cell neoplasms, but expression in follicular lymphoma was weak (33/69) or negative (four cases). Similarly, CD19 expression in diffuse large B-cell lymphomas was weak (28/56) or negative (eight cases). In T-cell-rich B-cell lymphomas, CD19 was also weak (4/10) or negative (three cases). CD19 was often absent in post-transplant B lymphoproliferative disease, classical Hodgkin's disease and plasma cell neoplasms. An unexpected finding was the frequent absence of CD19 in the neoplastic cells in lymphocyte predominant Hodgkin's disease.
Conclusions : CD19 can now be detected in routine biopsy specimens. In contrast to the classical pan-B marker CD20, CD19 is not always strongly expressed in B-cell neoplasms. Furthermore, the lymphocytic and histiocytic (L&H) cells of lymphocyte predominant Hodgkin's disease (which express most B-cell-associated markers) commonly lack CD19.