Cells carrying nonlymphoma-associated bcl-2/IgH rearrangements (NLABR) are phenotypically related to follicular lymphoma and can establish as long-term persisting clonal populations.

OBJECTIVE: Nonlymphoma-associated bcl-2/IgH rearrangements (NLABRs) are frequently amplified by PCR in blood of lymphoma-free subjects (LFS), but the temporal kinetics and phenotypic nature of NLABR-positive cells are unknown. To address these issues we prospectively monitored a panel of NLABR-positive LFS. METHODS: LFS have been studied by nested PCR, real-time PCR, and DNA sequencing. Cell selection studies were also performed to define the nature of NLABR-bearing clones. RESULTS: Of 125 donors, 16 (12.8%) were found to be bcl-2/IgH positive and were monitored at least every 6 months for a median time of 22 months (range 6-50). In half of the subjects the same NLABR detected initially was again reamplified at follow-up thrice or more. In 5, the same NLABR was constantly amplified in every follow-up sample. With a median follow-up of 22 months (range 9-50), no stable disappearance of a recurrent clone has been so far recorded. Real-time PCR indicated that persistent NLABR-positive clones are stable over time in the same subject. Cell separation studies indicate that NLABRs belong to CD19+, CD5-, CD23-, CD10+/- cells. CONCLUSIONS: Our results indicate that NLABR-positive clones are persistent populations phenotypically related to follicular lymphoma (FL). This suggests the existence of a FL-related clonal expansion of undetermined significance, which might be either a premalignant or a nonmalignant counterpart of FL.

Major tumor shrinking and persistent molecular remissions after consolidation with bortezomib, thalidomide, and dexamethasone in patients with autografted myeloma.

PURPOSE We investigated the effect on minimal residual disease, by qualitative and real-time quantitative polymerase chain reaction (RQ-PCR), of a consolidation regimen that included bortezomib, thalidomide, and dexamethasone (VTD) in patients with multiple myeloma (MM) responding to autologous stem-cell transplantation (auto-SCT). PATIENTS AND METHODS Patients achieving at least very good partial response who had an available molecular marker based on the immunoglobulin heavy-chain rearrangement received four courses of treatment every month: four infusions per month of bortezomib at 1.6 mg/m(2), thalidomide at 200 mg/d, and dexamethasone at 20 mg/d on days 1 to 4, 8 to 11, and 15 to 18. Patients were studied with tumor-clone-specific primers by qualitative nested PCR and RQ-PCR. Results Of 39 patients enrolled, 31 received the four VTD courses. Immunofixation complete responses increased from 15% after auto-SCT to 49% after VTD. Molecular remissions (MRs) were 3% after auto-SCT and 18% after VTD. Median time to maximum response was 3.5 months. So far, no patient in MR has relapsed (median follow-up, 42 months). VTD consolidation induced an additional depletion of 4.14 natural logarithms of tumor burden by RQ-PCR. Patients with a tumor load less than the median value after VTD had outcomes better than those who had tumor loads above the median value after VTD (at median follow-up: progression-free survival, 100% v 57%; P < .001). CONCLUSION To the best of our knowledge, this study is the first to document the occurrence of persistent MRs in a proportion of MM patients treated without allogeneic transplantation. Moreover, the major reduction in tumor load recorded by RQ-PCR after VTD suggests that unprecedented levels of tumor cell reduction can be achieved in MM thanks to the new nonchemotherapeutic drugs.

Rituximab induces effective clearance of minimal residual disease in molecular relapses of mantle cell lymphoma.

Molecular remission (MR) is associated with improved outcome in mantle cell lymphoma (MCL). If MR is not achieved, patients are at high risk of relapse. We retrospectively describe the molecular and clinical follow-ups of 4 patients with molecular relapses (M-rels) who were treated with rituximab. The 4 patients received rituximab-supplemented, high-dose sequential chemotherapy and autologous stem cell transplantation as induction treatment and achieved clinical remission and MR. M-rel was defined as polymerase chain reaction (PCR) positivity in 2 consecutive samples in the absence of clinical relapse. M-rels occurred at 3, 6, 39, and 52 months and were always confirmed by direct sequencing of the clonal rearrangement. Minimal residual disease was monitored by qualitative and real-time quantitative PCR. All patients received 4 courses of rituximab, with 2 additional infusions if PCR positivity remained. After 4-6 courses of rituximab, all patients re-entered MR. No clinical relapses were recorded at 3, 6, 18, and 62 months from treatment, although 1 patient had a second M-rel that was sensitive to rituximab. Our results indicate that rituximab is active against residual MCL cells and suggest that molecularly tailored maintenance therapy needs to be investigated in clinical trials.

Cyclooxygenase-2 (COX-2) is frequently expressed in multiple myeloma and is an independent predictor of poor outcome.

Cyclooxygenase 2 (COX-2) is an inflammation-associated enzyme involved in the pathogenesis of many solid tumors, but little is known about its presence and role in hematologic neoplasms. Multiple myeloma (MM) is known to involve a deregulated cytokine network with secretion of inflammatory mediators. We thus decided to investigate the involvement of COX-2 in this neoplasm. Western blotting (WB) was used to evaluate 142 bone marrow (BM) specimens, including MM and monoclonal gammopathy of undetermined significance (MGUS). Selected cases under-went further evaluation by WB on purified CD138(+) cells, immunohistochemistry (IC), and real-time polymerase chain reaction (PCR) for mRNA expression. COX-2 was expressed in 11% (2 of 18) of MGUS specimens, 31% (29 of 94) of MM at diagnosis, and 47% (14 of 30) of MM with relapsed/refractory disease. COX-2 positivity was associated with a poor outcome in terms of progression-free (18 vs 36 months; P < .001) and overall survival (28 vs 52 months; P < .05). Real-time PCR showed COX-2 mRNA overexpression. IC and cell separation studies demonstrated COX-2 expression to be restricted to malignant plasma cells. This is the first report of the presence and prognostic role of COX-2 expression in MM. Future studies will assess COX-2 involvement in other hematologic tumors and its potential use as a therapeutic or chemo-preventive target in onco-hematology.

Cytokine detection in HIV-1/HHV-8 co-infected subjects.

In a previous work we have evaluated some immunologic and haematologic parameters of HIV-1 positive subjects co-infected with HHV-8. A worsening of these values were generally described in these patients as compared with those HIV-1 positive, but negative for HHV-8. Now we have studied the influence of HHV-8 co-infection of HIV-1 positive subjects on the production of some cytokines to make clear the question of its role in the immuno-deregulation of the above-mentioned subjects. In particular we have analysed serum levels of IL-4 and IL-10, Th2 type T cells cytokines, IFN-gamma, an indirect marker of Th1 cells activation and IL-18, a cytokine produced by monocytic-macrophagic cells, which is able to induce IFN-gamma production and Th1 T lymphocytes activation. No significant differences were found as regards the IFN-gamma serum levels (92.1 +/- 24.3 pg ml(-1) in the case of HIV-1 positive/HHV-8 negative subjects and 96.0 +/- 17.4 pg ml(-1) in those HIV-1 positive/HHV-8 positive). In healthy subjects the mean level of this cytokine was 17.6 +/- 5.2 pg ml(-1) (significant difference with both the former values at p < 0.001). Moreover IL-4 and IL-10, which were undetectable in healthy individuals, showed the following values in HIV-1 positive/HHV-8 negative subjects: 31.9 +/- 2.7 pg ml(-1) and 119.8 +/- 85.1 pg ml(-1) respectively and in HIV-1 positive/HHV-8 positive subjects: 30.4 +/- 4.8 pg ml(-1) and 69.4 +/- 65.3 pg ml(-1) (not significant differences). In contrast IL-18 reached a mean level of 1001.2 +/- 360.5 pg ml(-1) in HIV-1 positive/HHV-8 negative subjects, but showed a significant reduction in HIV-1 positive/HHV-8 positive subjects (737.6 +/- 284.3 pg ml(-1) --> p < 0.05) and presented very low levels in healthy individuals (21.3 +/- 30.3 pg ml(-1)). Moreover a significant correlation (-0.984 --> p < 0.001) was noticed between IL-18 reduction in HIV-1 positive subjects co-infected with HHV-8 and the degree of positivity of HHV-8. These data suggest that HHV-8 co-infection has no influence on the switch Th1 --> Th2 in HIV-1 positive subjects, but is able to reduce IL-18 production, useful for Th1 subset restoration.

Telomere length correlates with histopathogenesis according to the germinal center in mature B-cell lymphoproliferative disorders.

In this study we investigated telomere restriction fragment (TRF) length in a panel of mature B-cell lymphoproliferative disorders (MBCLDs) and correlated this parameter with histology and histopathogenesis in relation to the germinal center (GC). We assessed 123 MBCLD samples containing 80% or more tumor cells. TRF length was evaluated by Southern blot analysis using a chemiluminescence-based assay. GC status was assessed through screening for stable and ongoing somatic mutations within the immunoglobulin heavy-chain genes. Median TRF length was 6170 bp (range, 1896-11 200 bp) and did not correlate with patient age or sex. TRF length was greater in diffuse large cell lymphoma, Burkitt lymphoma, and follicular lymphoma (medians: 7789 bp, 9471 bp, and 7383 bp, respectively) than in mantle cell lymphoma and chronic lymphocytic leukemia (medians: 3582 bp and 4346 bp, respectively). GC-derived MBCLDs had the longest telomeres, whereas those arising from GC-inexperienced cells had the shortest (P < 10(-9)). We conclude that (1) TRF length in MBCLD is highly heterogeneous; (2) GC-derived tumors have long telomeres, suggesting that minimal telomere erosion occurs during GC-derived lymphomagenesis; and (3) the short TRF lengths of GC-inexperienced MBCLDs indicates that these neoplasms are good candidates for treatment with telomerase inhibitors, a class of molecules currently the subject of extensive preclinical evaluation.