title: [Loss of CD20 expression following rituximab-combined chemotherapy in CD20-positive and CyclinD1-positive multiple myeloma].
abstract: Several studies have confirmed that CD20 is expressed in about 20% of multiple myeloma (MM) cases. This is closely related to a chromosomal translocation between chromosome 11 and chromosome 14, which results in the expression of CyclinD1. The use of rituximab (RIT) in the treatment of CD20-positive MM has been reported, however its effectiveness is still not well established. We encountered a case of CD20-positive/CyclinD1-positive MM; interestingly, CD20 expression could not be detected in MM cells following RIT-combined chemotherapy, while it gradually recovered when RIT therapy was discontinued. This is the first report in which the transition of CD20 expression was accurately analyzed by flow cytometry and immunohistochemical staining before, during and after RIT treatment. Consequently, this case provides insight regarding the mechanism through which CD20 expression is lost following RIT therapy for CD20-positive lymphoid neoplasm, as well as the efficacy of RIT in CD20-positive MM.
authors.affiliation: Department of Hematology and Oncology, Hokkaido University Graduate School of Medicine.
authors.forename: Souichi
authors.initials: S
authors.lastname: Shiratori
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: Kanako
authors.initials: K
authors.lastname: Kubota
authors.forename: Kentarou
authors.initials: K
authors.lastname: Wakasa
authors.forename: Makoto
authors.initials: M
authors.lastname: Ibata
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shono
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Takahata
authors.forename: Akio
authors.initials: A
authors.lastname: Shigematu
authors.forename: Naoko
authors.initials: N
authors.lastname: Kato
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ota
authors.forename: Junji
authors.initials: J
authors.lastname: Tanaka
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuno
authors.forename: Masahiro
authors.initials: M
authors.lastname: Asaka
authors.forename: Masahiro
authors.initials: M
authors.lastname: Imamura
mesh_terms: D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20 / Q000032:analysis*; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D019938:Cyclin D1 / Q000032:analysis*; D005260:Female; D015870:Gene Expression; D006801:Humans; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics*; D000069283:Rituximab; D016896:Treatment Outcome
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; C530104:CCND1 protein, human; D019938:Cyclin D1; D000069283:Rituximab