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CD 20 gene deletion causes a CD 20‐negative relapse in diffuse large B ‐cell lymphoma
Author(s) -
Nakamaki Tsuyoshi,
Fukuchi Kunihiko,
Nakashima Hidetoshi,
Ariizumi Hirotsugu,
Maeda Takashi,
Saito Bungo,
Yanagisawa Kouji,
Tomoyasu Shigeru,
Homma Mayumi,
Shiozawa Eisuke,
YamochiOnizuka Toshiko,
Ota Hidekazu
Publication year - 2012
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/j.1600-0609.2012.01838.x
Subject(s) - lymphoma , diffuse large b cell lymphoma , cancer research , phenotype , large cell lymphoma , gene , rituximab , immunology , biology , medicine , genetics
In diffuse large B ‐cell lymphoma ( DLBCL ), a CD 20‐negative relapse is clinically significant because it is associated with chemo‐refractory phenotypes and loss of a therapeutic target. The alteration of the CD 20 gene is reported as infrequent in CD 20‐negative relapse in B ‐cell lymphoma. We established a DLBCL cell line with loss of CD 20 expression ( SD 07) from a patient at CD 20‐negative relapse. She was initially diagnosed with CD 20‐positive DLBCL and received repeated immuno‐chemotherapy that included rituximab. SD 07, which has an immunoglobulin κ rearrangement identical to that of lymphoma cells at CD 20‐negative relapse, showed homozygous deletion of the CD 20 gene with loss of the copy number of 11q12. SD 07 is the first case in which it is proven that the loss of CD 20 expression in relapsed DLBCL is the result of deletion of the CD 20 gene. Deletion of the CD 20 gene is a molecular mechanism of CD 20‐negative relapse in a subset of DLBCL .