title: Follow-up data of 10 patients with B-cell non-Hodgkin lymphoma with a CD20-negative phenotypic change after rituximab-containing therapy.
abstract: Recently, a CD20-negative phenotypic change in CD20-positive B-cell non-Hodgkin lymphoma (B-NHL) after rituximab therapy was described. We report the follow-up data of 10 B-NHL patients showing this change after rituximab therapy. Ten patients (4 men and 6 women; median age, 57 y) with B-NHL who were initially CD20 positive and became CD20 negative after rituximab therapy were analyzed. Clinicopathologic features, including clinical course, CD20 expression, and histopathology, were examined. CD20 expression in lymphoma cells was evaluated using immunohistochemistry and/or flow cytometry. Histopathologically, diagnosis at initial presentation was follicular lymphoma (FL) in 7 patients; diffuse large B-cell lymphoma in 1; and chronic lymphocytic leukemia in 2. Six patients (60%, 3 FL, 1 diffuse large B-cell lymphoma, and 2 chronic lymphocytic leukemia patients) showed continuous CD20 negativity until 24 months after the phenotypic change. Three patients (30%) with FL regained CD20 expression within 1 to 7 months after detection of the CD20 change. Two patients (20%) with FL, including 1 who regained CD20 expression, showed heterogenous CD20 expression with a CD20-negative low-grade component and a CD20-positive large cell component. The overall response rate to therapy before the CD20-negative change was 70%. We reported the follow-up data of 10 B-NHL patients with a CD20-negative phenotypic change associated with rituximab-containing therapy. The most common histologic phenotypes were continuous CD20 negativity, recovery of CD20 expression within 7 months, and heterogenous CD20 expression. As the changes in morphology and CD20 expression after rituximab therapy vary widely, careful follow-up and rebiopsy are recommended.
authors: Department of Pathology and Clinical Laboratory, National Cancer Center Hospital, Tokyo, Japan. akmaeshi@ncc.go.jp
authors: Akiko M
authors: AM
authors: Maeshima
authors: Hirokazu
authors: H
authors: Taniguchi
authors: Suguru
authors: S
authors: Fukuhara
authors: Noriyuki
authors: N
authors: Morikawa
authors: Wataru
authors: W
authors: Munakata
authors: Dai
authors: D
authors: Maruyama
authors: Sung-Won
authors: SW
authors: Kim
authors: Takashi
authors: T
authors: Watanabe
authors: Yukio
authors: Y
authors: Kobayashi
authors: Kensei
authors: K
authors: Tobinai
authors: Hitoshi
authors: H
authors: Tsuda
mesh_terms: D058846:Antibodies, Monoclonal, Murine-Derived / Q000627:therapeutic use*; D018951:Antigens, CD20 / Q000378:metabolism*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008224:Lymphoma, Follicular / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D000069283:Rituximab
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D000970:Antineoplastic Agents; D000069283:Rituximab