These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: [Rituximab resistance in B-cell lymphoma and its elimination].
    Author: Hatake K, Terui Y.
    Journal: Gan To Kagaku Ryoho; 2009 Apr; 36(4):548-51. PubMed ID: 19381025.
    Abstract:
    Rituximab is commonly incorporated into CD20-positive B-cell lymphoma therapy to improve response and prognosis. With increasing use, resistance to rituximab is a continuing concern, but CD20 mutation as a cause of resistance has not previously been reported. Freshly collected lymphoma cells from 50 patients with previously untreated or relapsed/resistant non-Hodgkin's B-cell lymphomas(diffuse large B cell, n=22; follicular, n=7; mucosa associated lymphoid tissue, n=16; chronic lymphocytic leukemia, n=2; small lymphocytic lymphoma, n=1; lymphoplasmacytic, n =1; mantle cell lymphoma, n=1)were assessed for CD20 expression by flow cytometry, and CD20 gene sequencing was performed on extracted DNA. CD20 mutations were found in 11 of 50 patients(22.0%), and could be grouped as: C-terminal deletion(8.0%), early termination(10.0%), and extracellular domain(2.0%)or transmembrane domain (2.0%)mutations. The mean fluorescence intensity of CD20 on fresh lymphoma cells was significantly lower for the Cterminal deletion mutation(3.26; 95% CI: 0.09-6.89)compared with wild type(30.8; 95% CI: 22.4-39.2)(p<0.05). In contrast, early termination mutations did not show significant differences in CD20 expression compared with wild type (19.5; 95% CI: 10.7-28.4)(p>0.05). It is possible that C-terminal deletion mutations of CD20 may be related to relapse/resistance after rituximab therapy. These mutations should be examined in patients showing progression of disease after partial remission. Other mechanisms are also discussed.
    [Abstract] [Full Text] [Related] [New Search]