In 16 QC rounds between 2010 and 2017, the four laboratories received 208 bone marrow (BM) samples (126 FL; 82 MCL); 187 were analyzed, according to the EuroMRD Consortium guidelines, by both nested (NEST) polymerase chain reaction (PCR) and real-time quantitative (RQ) PCR for BCL2/IGH MBR or IGHV rearrangements.
Evaluation of MRD level by flow cytometry or molecular techniques in the era of the new BCR and Bcl-2 targeted inhibitors could identify the most cost-effective and durable treatment sequencing.
More recently treatment approaches have evolved, in particular with BCL2-pathway inhibitors, so that MRD analysis may be informative for most patients and clinical trials, potentially becoming a tool for managing CLL patients in clinical practice.
BCR signalling inhibitors, BCL2 antagonists, CAR-T cells) and methods to evaluate minimal residual disease constitute good examples of tools facilitating 'personalized' management of patients with CLL.
MRD for the bcl-2/IgH translocation was determined on bone marrow cells in a centralized laboratory belonging to the Euro-MRD consortium, using qualitative and quantitative polymerase chain reactions (PCRs).
We describe two multiplex TaqMan-based real-time PCR assays which can be used to detect and quantify the major and minor breatpoint cluster regions of IGH@/BCL2 fusion products in newly diagnosed FL, and to monitor minimal residual disease during treatment or early relapse.
This study of minimal residual disease was undertaken in parallel, to determine the rate of conversion from bcl-2 polymerase chain reaction (PCR) -detectable to -undetectable status and the corresponding effect on progression-free survival (PFS).
We investigated expression of multidrug resistance genes MDR1, LRP and BCRP and antiapoptotic gene Bcl-2 in leukemic cells at diagnosis, and MRD level at the end of induction therapy, and could not find obvious relations between these parameters.
The conversion of bcl-2 from positive to negative by PCR in BM and/or PB suggests a possible role for this treatment in clearing minimal residual disease and improving patients' outcome.
We therefore developed a four-color flow cytometry method that enables establishment of apoptosis-related protein expression such as Bcl-2, Bcl-x(L), Mcl-1 and Bax at diagnosis and in MRD.
To assess whether nonneoplastic Bcl-2/IgH rearrangements act as a confounding factor in the setting of minimal residual disease analysis by evaluating their incidence in a panel of lymphoma-free subjects, including cancer-free donors and chemotherapy-naive and chemotherapy-treated cancer patients.
Minimal residual disease was assessed by polymerase chain reaction (PCR) for bcl-2/IgH translocations, and chimerism by X,Y-FISH or PCR amplification of short tandem repeat sequences.
The t(14;18)(q32;q21) translocation is closely associated with follicular lymphoma (FL), and is routinely assessed with molecular methods exploring BCL2 breakpoints for both diagnosis and minimal residual disease (MRD) monitoring.
Seventy-two patients with non-Hodgkin's lymphoma were evaluated for the presence of molecular markers (IgH, bcl-1, bcl-2 rearrangement) on bone marrow, at diagnosis and after PBSCT, and on harvests in order to find a possible predictive role of minimal residual disease on treatment outcome.
The presence of circulating Bcl-2/IgH+ cells, other than those derived from the malignant clone, could confound the detection and quantitation of minimal residual disease in patients with FL, particularly at low levels of tumor burden.
Thus, the results show that PCR detection of the bcl-2/IgH rearrangement is a very useful method in evaluating the BM infiltration by lymphoma cells especially in the situation of MRD.
The conversion of bcl-2 from positive to negative by PCR in blood and/or marrow suggests possible clearing of minimal residual diseasenot previously demonstrated by CHOP chemotherapy alone.
The t(14;18) gives rise to a rearrangement of the bcl-2 oncogene that constitutes an excellent target for detection of MRD by polymerase chain reaction (PCR).
Both Southern transfer and polymerase chain reaction (PCR) technologies are used to assess for B- and T-cell clonality, the presence of rearrangements involving protooncogenes such as bcl-1 and bcl-2, and the monitoring of minimal residual disease.