Article

Tumor load in patients with follicular lymphoma post stem cell transplantation may correlate with clinical course.

Department of Pathology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
Bone Marrow Transplantation (Impact Factor: 3.47). 09/2003; 32(3):287-91. DOI: 10.1038/sj.bmt.1704130
Source: PubMed

ABSTRACT The purpose of this study was to evaluate if the tumor load, as determined by a real-time quantitative PCR (RQ-PCR) assay, correlated with the clinical course of follicular lymphoma patients after stem cell transplantation (SCT). Cryopreserved bone marrow and/or peripheral blood samples obtained at different time intervals after SCT from 11 patients (seven allogeneic, T-cell depleted/four autologous) were tested for tumor load, as defined by t(14;18) positive cells/total cells, using RQ-PCR. None of the six patients who remained in remission had samples with a tumor load >0.01% after SCT, although fluctuating tumor loads of </=0.01% were observed in three of these patients. In contrast, four of the five patients (three allogeneic/two autologous) with relapsed/progressive disease had increasing tumor loads of >0.01% after SCT (0/6 vs 4/5, P<0.02, Fisher's exact). Our results suggest that RQ-PCR measurable tumor load >0.01% after SCT may correlate with relapsed/progressive disease. Prospective studies with greater numbers of cases are indicated to better determine the critical tumor load that predicts poor outcome after SCT with RQ-PCR.

Download full-text

Full-text

Available from: Carolyn A Keever-Taylor, Jun 26, 2014
0 Followers
 · 
80 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In order to increase the prognostic significance of polymerase chain reaction (PCR) data it has been suggested that quantitative PCR can be used to measure tumor burden. However, this option has not yet been definitely supported or refuted in patients with follicular lymphoma (FL). We decided to evaluate whether knowledge of the quantitative level of minimal residual disease and its variations can be of use in the management of FL patients. We used qualitative and competitive PCR to study 11 patients with refractory or relapsed FL harboring the t(14;18) translocation who underwent autologous (nine patients) or allogeneic (two patients) stem cell transplantation (SCT). Competitive PCR was performed with a multiple competitor carrying specific sequences including Bcl2/IgH MBR and mcr, and the beta-globin gene. After a median post-SCT follow-up of 44 months (range, 12-62), overall survival was 91% and disease-free survival 82%. The quantitative PCR data showed that: 1) effective chemotherapy before SCT substantially (1-2 log) reduced the tumor burden in the bone marrow (BM); 2) the increase in rearranged DNA detected in BM was associated with disease progression and relapse; 3) a PCR-negative autograft seemed to lead to lasting molecular remission even when it was performed in patients with a low level of BM infiltration before transplant; and 4) allo-SCT made and maintained the BM PCR negative even in the presence of a greater tumor burden before SCT. Six of the nine patients having CR after SCT (four auto and two allo) are in continuous molecular remission. In FL patients qualitative and quantitative PCR may provide data that can be helpful for the prognostic evaluation of tumor progression and the early detection of impending relapse by highlighting biological features such as the quality of the infused material, the tumor burden at transplant, and the behavior of tumor cells after transplant.
    Tumori 91(1):59-66. · 1.09 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the design of high speed printed circuit boards (PCBs), differential signals are preferred to distribute clock signals across the board. Differential signals are highly resistant to other signals or external fields, and do not cause strong radiation levels, due to the field cancellation resulting from the signal's opposite polarity, Differential signals can also reduce the generation of common mode (CM) currents. This paper examines the potential cancellation of common mode currents due to the relative phase shift between signals on two parallel transmission lines on a PCB. The main parameters of interest are the relative phase shift itself and the trace separation. This case is expanded towards the more general one of the common mode cancellation in meandered traces, which are used as delay lines. In an intermediate step, the signal direction in one of the transmission lines is reversed in order to study the excited current distribution within the reference plane. From the conclusions of the numerically obtained results, algorithmic improvements are derived for the use within EMC-Expert systems.
    Electromagnetic Compatibility, 2002. EMC 2002. IEEE International Symposium on; 09/2002
  • [Show abstract] [Hide abstract]
    ABSTRACT: Quantitative real-time polymerase chain reaction (qPCR) is a suitable method to measure residual disease in hematological malignancies. Our objective was to assess a LightCycler-based qPCR for t(14;18)(q32;q21)(IgH/bcl-2)-positive cells quantification in the context of clinical and morphopathological characteristics of patients with follicular lymphoma treated with rituximab (R) in combination with conventional or high-dose chemotherapy. A total of 270 bone marrow (BM) and peripheral blood (PB) samples collected from 52 patients with follicular lymphoma at diagnosis or at relapse before or sequentially during therapy were examined by qPCR and nested-PCR. A greater amount of t(14;18)-positive cells was observed in BM in comparison with PB in 76% of paired samples. The presence and number of t(14;18)-positive cells in BM and PB correlated with lymphoma activity. Significantly higher numbers of lymphoma cells were found in patients under non-remission compared with patients in clinical remission. During non-remission, 10-fold higher numbers were measured at relapse than at diagnosis. During remission, significantly higher levels were found in partial compared with complete remission. During first-line therapy, R/cyclophosphamide/adriamycin/vincristine/prednisone (CHOP) had higher in vivo purging ability than R/fludarabine/mitoxantrone (FM). After R/high-dose cytosine-arabinoside and mitoxantrone (HAM) or R/carmustine/etoposide/cytarabine/melphalan (BEAM), the level of t(14;18)-positive cells dropped below the detection limit in 80% of patients. LightCycler qPCR is a reliable method for quantitative molecular monitoring of t(14;18)-positive cells in BM and PB of patients with follicular lymphoma. It reflects the clinical characteristics of patients and allows assessment of response to different treatment regimens on a molecular level.
    European Journal Of Haematology 05/2005; 74(4):282-92. DOI:10.1111/j.1600-0609.2004.00391.x · 2.41 Impact Factor