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Some evidences suggest that telomere restriction fragment length (TRF-L) is an effective indicator of histopathogenesis in B-cell tumors. As histopathogenesis is relevant for B-cell chronic lymphocytic leukemia (B-CLL) prognosis, TRF-L was assessed by Southern blot in 201 patients and compared to variable immunoglobulin heave chain gene mutational status (VH-MS) and to other known prognostic features. Overall survival (OS), time to first treatment (TTFT) and progression-free survival (PFS) were evaluated. Our results indicate the following: (1) TRF-L is heterogeneous among B-CLL patients (median 6014 bp, range 1465-16 762); (2) TRF-L correlates to VH-MS (r(2)=0.1994, P<0.0001) with VH-mutated patients showing long and VH-unmutated short telomeres; however, 41% of VH-unmutated and 5% of VH-mutated patients did not show this correlation and were thus defined as 'discordant'; (3) TRF-L effectively predicts outcome in terms of TTFT, PFS and OS; (4) VH-unmutated discordant patients have a better clinical outcome than VH-unmutated concordant patients (OS P<0.01, PFS P<0.05) and similar to that of VH-mutated patients (OS, PFS P=NS). Compared to VH-unmutated concordant patients, VH-unmutated discordant patients showed no peculiarity in their immunoglobulin rearrangement nor in their flow cytometry or fluorescence in situ hybridization profile. In conclusion, TRF-L can be helpful to refine prognostication of B-CLL patients, particularly those with a VH-unmutated immunoglobulin sequence.

The aim of this study was to investigate feasibility, tolerability and efficacy of rituximab-supplemented high-dose sequential chemotherapy (R-HDS) with peripheral blood progenitor cell autografting as frontline or salvage treatment in patients with advanced non-Hodgkin's lymphoma (NHL). Thirty-two patients have been treated: 14 at disease onset and 18 with relapsed or progressive disease. R-HDS regimens included six courses of rituximab. Rituximab was delivered either concurrently with high-dose chemotherapy to exploit the in vivo purging properties of the drug as well as at the end of the treatment plan to target minimal residual disease. All patients treated at disease onset completed their treatment with no life-threatening toxicity, while two toxic deaths due to severe bilateral pneumonia were observed among patients treated due to relapsed or refractory disease. Thirteen of 14 patients treated up-front achieved CR. Among pre-treated patients 10 of 18 achieved CR with better results in patients with relapsed (seven of eight) compared to progressive disease (three of 10). PCR analysis was carried out in indolent lymphoma patients: nine of nine follicular lymphomas and three of six CD5-positive NHL collected PCR-negative peripheral blood progenitor cell harvests. The results of this pilot study show that R-HDS is feasible and effective with acceptable toxicity when used at disease onset. In pre-treated patients this treatment also showed promising results, although the risk of severe infections needs to be considered.

The feasibility and efficacy of a novel immunomagnetic ex vivo negative purging method was evaluated on peripheral blood progenitor cells (PBPC) from 13 non-Hodgkin's lymphoma patients (eight follicular, FL; three mantle cell, MCL; two FL with histologic transformation). A peculiar feature of the study was the collection of PBPC after prolonged tumor debulking. Our method included a stem cell enrichment phase followed by cell incubation with anti-B cell MoAbs (anti-CD19, CD20, CD22, CD23), addition of immunobeads, and then positive cell removal by passage on a Max-Sep (Baxter Immunotherapy) cell separator. Engraftment was rapid and stable. Hematological values were assessed 1 and 2 years after the autograft. Purging efficacy was molecularly assessed in a panel of 11 patients who showed persistence of PCR-detectable lymphoma cells on PBPC harvests despite intensified chemotherapeutic debulking. PCR-negativity was obtained in vitro and persisted in vivo after autograft in three FL patients; five more FL patients, whose purged PBPC were PCR+, converted to stable (3 patients) or fluctuating (two patients) PCR negativity after autograft. MCL patients never reached PCR negativity. Thus, ex vivo purging may have a role for FL patients harvesting PCR-positive PBPC after intensified chemotherapy. In contrast, the addition of ex vivo purging seems to be of little if any benefit for MCL patients.

Several methods have been developed for the detection of minimal residual disease (MRD) in B cell tumors. Chromosomal translocations or the rearrangement of the immunoglobulin heavy chain (IgH) and T cell receptor genes are generally employed. We report a novel PCR method to detect MRD using IgH genes. IgH rearranged variable region (VDJ) were amplified from tumor specimens using consensus primers for variable and joining region genes. Complementarity-determining regions (CDR) were identified and used to generate tumor-specific primers. Two-round amplifications using primers derived from CDRs and joining or constant regions were performed for MRD detection. IgH nested-PCR approach was tested on a panel of 75 B cell tumors including acute lymphoblastic and chronic lymphocytic leukemias, non-Hodgkin's lymphomas and multiple myelomas. A VDJ sequence was obtained in 62 out of 75 cases (83%). Sensitivity using DNA or cDNA templates was 10(-5) and (-6), respectively. This method is specific and sensitive and provides a simple, non-radioactive approach for the evaluation of MRD in B cell tumors.

The role of loss or inactivation of the retinoblastoma (Rb1) and p53 tumor suppressor genes in the pathogenesis of various human malignancies has been well established, yet little is known regarding plasma cell dyscrasias. In the present study, the loss of Rb1 protein expression, and the presence of Rb1 gene rearrangements as well as the presence of p53 somatic mutations (exons 5 through 9) were investigated in a panel of plasma cell dyscrasias, including 15 monoclonal gammopathies of undetermined significance (MGUS), 63 multiple myelomas (MM), and 18 plasma cell leukemias (PCL). In the same panel of cases, we established the frequency of ras oncogene mutations, the main genetic lesion associated with MM. We report that loss of Rb1 protein and p53 mutations are detectable in 34.7 and 9.8% of MM and PCL primary cases; no lesion was found in MGUS. In advanced stage MM, and PCL cases, Rb1 and p53 inactivation, as well as ras mutations were detected. Our findings show that Rb1 and p53 inactivation are associated with aggressive plasma cell dyscrasias, suggesting a role for these lesions in tumor progression rather than initiation.

Multiple myeloma (MM) is a B-cell malignancy characterized by clonal expansion of plasma cells producing monoclonal immunoglobulins. It has been regarded as a tumor typically involving only the bone marrow. The existence of circulating tumor cells has been suggested from phenotypic and genotypic studies. However, this issue is still controversial due to the limitations of the methods so far used. We describe a novel polymerase chain reaction (PCR) based method using clone-specific immunoglobulin heavy-chain gene sequences as tumor markers. From such sequences patient-specific oligonucleotide primers and probes were generated, and used to detect tumor cells. Seven MM patients were selected for this study, and tumor cells were found in all peripheral blood samples. The demonstration of circulating tumor cells suggests some caution when using peripheral blood for autograft procedures, even though its contamination is lower than bone marrow. In conclusion, we describe a specific and sensitive PCR-based method for detecting minimal disease which is of general applicability to all lymphoid malignancies transcribing rearranged immunoglobulin heavy-chain genes.