Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q06643 (non-Hodgkin's lymphoma)
 11,307 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A controversy persists in autologous transplantation as to which source of progenitor cells, bone marrow (BM) or peripheral blood (PB), contains the lowest number of contaminating lymphoma cells, and how mobilization procedures affect these numbers. To accurately measure the number of non-Hodgkin's lymphoma (NHL) cells harboring the bcl-2/immunoglobulin H (IgH) rearrangement in progenitor cell grafts, we developed a nested quantitative competitive polymerase chain reaction assay (QC-PCR). DNA from lymph nodes of four patients with NHL were cloned into the pSK(+) vectors to generate four internal controls (ICs) (two with major breakpoint region [MBR] and two with minor cluster region [mcr] rearrangements). The kinetics of amplification of ICs paralleled those of bcl-2/IgH rearranged genomic DNA. When used in a QC-PCR assay, these ICs were accurate at a 0.2-log level and provided reproducible results, as shown by low intrarun and interrun variability. An excellent correlation between predicted and observed lymphoma cell content (r = .99) was observed over a range of at least 5 logs of rearranged cells. This approach was used to measure involvement by NHL cells at the time of progenitor cell harvest in 37 autologous transplant patients. The number of bcl-2/IgH rearranged cells in BM, PB, and mobilized PB (mPB) was found to vary from 1 to 1.1 x 10(5) per million cells. The number of lymphoma cells present in BM was significantly higher than in PB (P = .0001), with a median difference in lymphoma cell content between BM and PB of 0.48 log of cells (range, -0.7 to 5 logs). In contrast, we found no difference in the concentration of bcl-2/IgH rearranged cells present in BM versus PB progenitor cells mobilized with cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) (mPB) (P = .57). In conclusion, the QC-PCR assay described in this study could measure accurately and reproducibly the number of bcl-2/IgH rearranged cells among normal cells. Differences in levels of contamination by lymphoma cells between BM and PB were of less than one log (10-fold), and no differences in lymphoma cell concentrations were observed between BM and mobilized PB. As more cells are usually infused with mPB than with BM grafts, mPB progenitor cell grafts may actually be associated with higher levels of contamination by lymphoma cells. Furthermore, this QC-PCR assay should provide an important tool to assess the prognostic impact of lymphoma cell burden both in progenitor cell grafts and in vivo.
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PMID:Lymphoma cell burden in progenitor cell grafts measured by competitive polymerase chain reaction: less than one log difference between bone marrow and peripheral blood sources. 941 2

Rituximab is a monoclonal antibody against the CD20 molecule which is used to treat B-cell lymphomas. In 60% of low-grade B lymphomas in which rituximab was effective at first, there was no clinical response in a second treatment and a few cases of follicular lymphomas (FL) with transformation to diffuse large B-cell lymphoma (DLBCL) have been reported. We describe a new case and hypothesize about the mechanisms of transformation: a 52-year-old man, in follow-up during 8 years for FL, who after rituximab treatment and complete remission of FL showed progressive disease involving the liver and duodenal mucosa. Immunohistochemical and molecular studies were performed on paraffin-embedded tissue samples of lymph nodes, the small intestine, and liver tumors. After rituximab treatment, biopsies of a liver lesion and the small bowel both showed CD20-negative large B-cell lymphoma. Molecular study of the initial and relapse specimens shows a CDR2 IgH rearrangement with the same height and t14;18 (MBR). The rapid relapse with the same rearrangement of IgH seems to support the interpretation that the change of grade of lymphoma and loss of CD20 expression occurred before rituximab treatment. The existence of a varying proportion of a CD20-negative cell population in every B-cell lymphoma which does not respond to rituximab should therefore be considered. The reduction of CD20 expression could be a resistance mechanism to rituximab retreatment in DLBCL as a consequence of the progression of low-grade B-cell non-Hodgkin's lymphoma (B-NHL). It is necessary to perform new biopsies to evaluate CD20 expression in relapse or the progression of B-cell lymphoma after rituximab treatment.
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PMID:CD20-negative DLBCL transformation after rituximab treatment in follicular lymphoma: a new case report and review of the literature. 1289 84