Histological and immunophenotypic changes in 59 cases of B-cell non-Hodgkin's lymphoma after rituximab therapy.

Abstract

Rituximab is a chimeric monoclonal antibody that recognizes the CD20 antigen. It has been used to treat B-cell non-Hodgkin lymphoma (B-NHL), but recently rituximab resistance has been a cause for concern. We examined histological and immunohistochemical changes in 59 patients with B-NHL after rituximab therapy. The patients comprised 32 men and 27 women with a median age of 59 years. Pre-rituximab specimens comprised 34 follicular lymphomas (FL), 11 diffuse large B-cell lymphomas (DLBCL), 10 mantle cell lymphomas, two marginal zone B-cell lymphomas (MZBCL), and two chronic lymphocytic leukemias (CLL). CD20 expression in lymphoma cells was evaluated by immunohistochemistry or flow cytometry. Post-rituximab materials were taken a median of 6 months (4 days to 59 months) after rituximab therapy. Sixteen cases (27%) showed loss of CD20 expression with four histological patterns: pattern 1, no remarkable histological change (FL, 5; DLBCL, 3; and CLL, 2); pattern 2, proliferation of plasmacytoid cells (FL, 2; DLBCL, 1; and MZBCL, 1); pattern 3, transformation to classical Hodgkin's lymphoma (FL, 1); and pattern 4, transformation to anaplastic large cell lymphoma-like undifferentiated lymphoma (FL, 1). Loss of CD20 was unrelated to the interval of biopsies, treatment regimen, clinical response, and frequency of rituximab administration. Loss of CD20 within 1 month of rituximab therapy (3/14, 21%) and regain of CD20 (2/7, 29%) were not frequent. CD20-positive relapse with transformation occurred most frequently in cases of early relapse. In conclusion, B-NHL showed various histological and immunophenotypic changes after rituximab therapy, including not only CD20 loss but also proliferation of plasmacytoid cells or transformation to special subtypes of lymphoma.

• Authors: Akiko Miyagi Maeshima, Hirokazu Taniguchi, Junko Nomoto, Dai Maruyama, Sung-Won Kim, Takashi Watanabe, Yukio Kobayashi, Kensei Tobinai, Yoshihiro Matsuno
• Journal: Cancer science (Cancer Sci) Vol. 100 Issue 1 Pg. 54-61 (Jan 2009) ISSN: 1349-7006 [Electronic] England
• PMID: 19038008 (Publication Type: Journal Article)

Chemical References

• Antibodies, Monoclonal
• Antibodies, Monoclonal, Murine-Derived
• Antigens, CD20
• Antineoplastic Agents
• Rituximab

Topics

• Adult
• Aged
• Aged, 80 and over
• Antibodies, Monoclonal (therapeutic use)
• Antibodies, Monoclonal, Murine-Derived
• Antigens, CD20 (analysis)
• Antineoplastic Agents (therapeutic use)
• Female
• Humans
• Immunophenotyping
• Lymphoma, B-Cell (drug therapy, immunology, pathology)
• Male
• Middle Aged
• Rituximab