Nowadays, resistance to rituximab has become a major issue in clinical practice. And loss of CD20 may contribute to it. Here we presented a case of loss of CD20 expression in relapsed diffuse large B cell lymphoma tre...Nowadays, resistance to rituximab has become a major issue in clinical practice. And loss of CD20 may contribute to it. Here we presented a case of loss of CD20 expression in relapsed diffuse large B cell lymphoma treated with rituximab and discuss the incidence, mechanism, influence factors, specific markers, prognosis and treatment of this disease. These results suggested that a post-relapse biopsy after rituximab treatment shguld be performed. CD79a and Pax-5 should be used as the first-line B lineage-specific markers for these patients. Though mechanisms of CD20 decrement are not fully elucidated, the down-regulation of CD20 mRNA is the most probable hypothesis. Recently various new agents are developed, but the prognosis is still poor. Further studies for new treatments are needed.展开更多
文摘Nowadays, resistance to rituximab has become a major issue in clinical practice. And loss of CD20 may contribute to it. Here we presented a case of loss of CD20 expression in relapsed diffuse large B cell lymphoma treated with rituximab and discuss the incidence, mechanism, influence factors, specific markers, prognosis and treatment of this disease. These results suggested that a post-relapse biopsy after rituximab treatment shguld be performed. CD79a and Pax-5 should be used as the first-line B lineage-specific markers for these patients. Though mechanisms of CD20 decrement are not fully elucidated, the down-regulation of CD20 mRNA is the most probable hypothesis. Recently various new agents are developed, but the prognosis is still poor. Further studies for new treatments are needed.