Demonstration for cold atmospheric pressure plasma jet operation and antibacterial action in microgravity.

Cold atmospheric pressure plasma (ionized gas) is an innovative medical tool for the treatment of infected wounds thanks to its potential to inactivate drug-resistant microorganisms and promote tissue regeneration and vascularization. The low power consumption, compactness, and versatility of Cold Atmospheric Pressure Plasma (CAPP) devices make them an ideal tool for risk mitigation associated with human spaceflights. This work presents results in microgravity on the operability of CAPP and its antimicrobial effect. The experiments carried out in parabolic flights make it possible to optimize the treatment conditions (i.e., the distance, the gas mixture) and to obtain the rapid inactivation (<15 s) of Escherichia coli samples. Interestingly, the inactivation efficiency of CAPP was higher during parabolic flights than under terrestrial conditions. Overall, these results encourage the further development of CAPP medical devices for its implementation during human spaceflights.

Prognostic value of estrogen receptor and Ki-67 index after neoadjuvant chemotherapy in locally advanced breast cancer expressing high levels of proliferation at diagnosis.

PURPOSE: Breast cancers expressing high levels of Ki-67, a nuclear marker of cell proliferation, are associated with worse outcome. Recent data from neoadjuvant studies indicate that a single measurement of the nuclear proliferation marker Ki-67 in breast carcinoma during neoadjuvant therapy is strongly predictive of long-term outcome. Secondly, recent literature data indicate that prognostic evaluation with Ki-67 may be better after pre-surgical therapy. A retrospective study from a prospectively maintained clinical database to compare the predictive and prognostic significance of biological markers, assessed before and after neoadjuvant chemotherapy, in locally advanced breast cancer, was performed. PATIENTS AND METHODS: The following parameters were considered before and after chemotherapy for their relationship with treatment response and disease-free survival in 64 patients with locally advanced breast cancer: clinical stage, clinical and pathological lymph node involvement, Ki-67, estrogen receptor (ER), progesterone receptor (Pgr), Her2, tumor grade, clinical response, type of surgery performed, and number of chemotherapy cycles administered. The expression of Ki-67 was assessed using immunohistochemistry in pre-therapy tru-cut and post-therapy surgical excision specimens after neoadjuvant chemotherapy; only patients with breast tumors expressing high baseline Ki-67 (≥ 15%) were included in the analysis. In addition, the correlation between pre-chemotherapy biological markers and clinical and pathological response was reported. RESULTS: Post-chemotherapy Ki-67 proliferation index decrease, pre-chemotherapy ER expression and post-chemotherapy ER expression were the only significant prognostic factors adversely influencing disease-free survival in univariate analysis. Her2 overexpression was the only factor to impact on the clinical response. CONCLUSIONS: Post-treatment Ki-67 and ER status were predictors of outcome for patients with locally advanced breast cancer and a high pre-chemotherapy proliferation index.

Liposomal amphotericin B in the treatment of visceral leishmaniasis in immunocompromised patients.

Leishmaniasis is a zoonosis caused by a protozoan of the Leishmania genus. First-line treatment for all forms is currently represented by the use of antimony derivatives, although toxic effects and the number of resistant strains in both immunocompromised and immunocompetent patients is increasing. Liposomal amphotericin B (L-AMB) is less toxic, more effective, and better tolerated, especially in human immunodeficiency virus-negative immunocompromised patients. We present 2 cases of transplanted patients affected by visceral leishmaniasis treated successfully with L-AMB.

Bortezomib, doxorubicin and dexamethasone in advanced multiple myeloma.

BACKGROUND: Bortezomib has shown significant activity in myeloma. In this multicenter trial, we assessed for the first time the combination of bortezomib, doxorubicin and low-dose dexamethasone (PAd) in the treatment of relapsed/refractory myeloma. PATIENTS AND METHODS: Sixty-four patients were treated for a median of four 28-day cycles (1-6). Bortezomib was given at 1.3 mg/m(2) (days 1, 4, 8, 11) and dexamethasone at 40 mg (days 1-4); 34 patients receive doxorubicin at 20 mg/m(2) (days 1, 4) while 30 patients pegylated liposomal doxorubicin at 30 mg/m(2) (day 1). RESULTS: Fifty-eight percent of patients had undergone prior autologous transplantation, 70% prior anthracycline and 27% prior bortezomib-based regimens. Forty-three patients (67%) achieved at least a partial response including 16 (25%) with at least a very good partial response. One-year event-free survival was 34% after PAd and 31% after the previous line of therapy (hazard ratio 1.20, 95% confidence interval 0.76-1.90, P = 0.43). One-year overall survival from the start of PAd was 66%. Grade 3-4 toxic effects included thrombocytopenia (48%), neutropenia (36%), infections (15%), anemia (13%), gastrointestinal disturbances (11%) and peripheral neuropathy (10%). Two patients had grade 3-4 cardiac heart failure. CONCLUSIONS: PAd is an active salvage therapy with manageable toxicity in patients with relapsed/refractory myeloma.

Hyperhomocysteinemia is associated with cognitive impairment in multiple sclerosis.

Hyperhomocysteinemia (HHcy) has been associated with cognitive impairment in various neurological diseases. Cognitive impairment occurs early in multiple sclerosis (MS). Conflicting data have been reported regarding plasma total homocysteine (tHcy) levels in MS patients, and the impact of HHcy on cognitive impairment in MS is not known. This study investigated whether plasma total homocysteine levels are increased in MS and if HHcy is associated with cognitive impairment in MS. We compared tHcy levels in 94 patients with MS and 53 healthy age-matched controls. We used a neuropsychological test battery that included the Raven's Coloured Progressive Matrices, the Visual Search Test, the Trail Making Test A and B, the Immediate and Delayed Recall of a Short Story, the 30 Paired Word Associates, the Rey-Osterrieth Complex Figure Test, and the Semantic and Verbal Fluency Tests. Clinical (sex, age, type of MS, relapse, disease duration, coexisting disease, smoking habit, and physical disability) and laboratory variables (HHcy, low serum levels of folate and vit.B12, MTHFR genotype) were evaluated for their ability to predict cognitive impairment. The mean tHcy was higher in patients (13.19 micromol/L, SD5.58) than in controls (9.81 micromol/L, SD2.53; p < 0.001). Univariate analysis determined the following factors to be associated with cognitive impairment: higher age at observation, chronic progressive course of disease, longer disease duration,moderate or severe physical disability, and frequency of HHcy. With multivariate regression analysis, there remained a significant association only between frequency of HHcy and cognitive impairment (beta 0.262, p = 0.01). We conclude that tHcy levels are increased in MS and that HHcy is associated with cognitive impairment in this disease.

Effects of miRNA-15 and miRNA-16 expression replacement in chronic lymphocytic leukemia: implication for therapy.

Chronic lymphocytic leukemia (CLL) clones are characterized by loss of a critical region in 13q14.3, (del(13)(q14)) involving the microRNA (miRNA) cluster miR-15a and miR-16-1. We have investigated the effects of replacement of miR-15a and miR-16-1. CLL cells transfected with these miRNA mimics exhibited a decrease in cell viability in vitro and impaired capacity for engraftment and growth in NOD/Shi-scid,γcnull (NSG) mice. No synergistic effects were observed when the two miRNA mimics were combined. The phenomena were not restricted to CLL with the del(13)(q14) lesion. Similar effects induced by miRNA mimics were seen in cells with additional chromosomal abnormalities with the exception of certain CLL clones harboring TP53 alterations. Administration of miRNA mimics to NSG mice previously engrafted with CLL clones resulted in substantial tumor regression. CLL cell transfection with miR-15a and miR-16-1-specific inhibitors resulted in increased cell viability in vitro and in an enhanced capacity of the engrafted cells to grow in NSG mice generating larger splenic nodules. These data demonstrate that the strong control by miR-15a and miR-16-1 on CLL clonal expansion is exerted also at the level of full-blown leukemia and provide indications for a miRNA-based therapeutic strategy.

The role of high-dose therapy and autologous stem cell transplantation in patients with primary refractory Hodgkin's lymphoma: a report from the Gruppo Italiano per lo Studio dei Linfomi (GISL).

GISL recently conducted an exhaustive survey of 1078 patients with Hodgkin's Lymphoma (HL) enrolled between 1988 and 2002 in different prospective trials. Treatment failure was observed in 82 out of 1078 patients; of these 82 patients with refractory HL, complete information was available for 72, who form the evaluable population of the present study. After the initial therapy failure, 51 patients were treated with conventional salvage chemotherapy (CC) (n = 24) or high-dose chemotherapy (HDC) (n = 27); 4-year overall survival (OS) was 81% in the HDC group versus 38% in the CC group (P = 0.019). The remaining 21 patients had rapidly progressive disease and died. After a median follow-up of 2.8 years, the projected OS for all 72 patients is 58 and 49% at 3 and 5 years, respectively. Age <45 years, the absence of systemic symptoms and a PS <1 predicted a significantly longer OS. Interestingly, the majority of patients with two or three negative prognostic factors did not receive potentially curative therapy. In conclusion, HDC seems to be a reasonable option for selected patients with refractory HL, although the majority of them did not receive a transplant. Finally, patients with a high-risk score had little chance of receiving potentially curative treatment.

A phase II, single-arm, prospective study of bendamustine plus melphalan conditioning for second autologous stem cell transplantation in de novo multiple myeloma patients through a tandem transplant strategy.

This phase II trial evaluates, for the first time, the safety and efficacy of bendamustine plus high-dose melphalan (HDM) as a conditioning regimen before the second autologous stem cell transplantation (ASCT) in previously untreated multiple myeloma (MM) patients. In total, 32 ASCT patients received HDM (200 mg/m(2)) as conditioning for the first ASCT. After 3-6 months from the first ASCT, responding patients underwent a second ASCT following bendamustine (200 mg/m(2)) and HDM (140 mg/m(2)). High-dose chemotherapy and ASCT were performed with complete neutrophil and platelet recovery in all patients. The median number of days to neutrophil and platelet engraftment was 11 (range 9-15) and 12 (range 10-19), respectively. Only one subject experienced grade 3 diarrhea; the rate of mucositis and vomiting was significantly lower with the bendamustine plus HDM regimen compared with the HDM-only regimen (81.2 vs 96.9%, P=0.025 and 78.1 vs 100%, P=0.008). Overall response rate (ORR) was 81.2% after the first transplant, and 90.6% after the second, while complete response rates were 46.8 and 62.5%, respectively (P=0.016). Actuarial 2-year PFS and OS were 79% (95% confidence interval (CI), 60-98) and 97% (95% CI, 91-100), respectively. Bendamustine+HDM is feasible as the conditioning regimen for second ASCT in MM patients. The present study may pave the way for phase III studies specifically aimed at further investigating this combination strategy. The role of this combination in MM for conditioning regimen in a first or single ASCT setting should be also investigated.

lncRNA profiling in early-stage chronic lymphocytic leukemia identifies transcriptional fingerprints with relevance in clinical outcome.

Long non-coding RNAs (lncRNAs) represent a novel class of functional RNA molecules with an important emerging role in cancer. To elucidate their potential pathogenetic role in chronic lymphocytic leukemia (CLL), a biologically and clinically heterogeneous neoplasia, we investigated lncRNAs expression in a prospective series of 217 early-stage Binet A CLL patients and 26 different subpopulations of normal B-cells, through a custom annotation pipeline of microarray data. Our study identified a 24-lncRNA-signature specifically deregulated in CLL compared with the normal B-cell counterpart. Importantly, this classifier was validated on an independent data set of CLL samples. Belonging to the lncRNA signature characterizing distinct molecular CLL subgroups, we identified lncRNAs recurrently associated with adverse prognostic markers, such as unmutated IGHV status, CD38 expression, 11q and 17p deletions, and NOTCH1 mutations. In addition, correlation analyses predicted a putative lncRNAs interplay with genes and miRNAs expression. Finally, we generated a 2-lncRNA independent risk model, based on lnc-IRF2-3 and lnc-KIAA1755-4 expression, able to distinguish three different prognostic groups in our series of early-stage patients. Overall, our study provides an important resource for future studies on the functions of lncRNAs in CLL, and contributes to the discovery of novel molecular markers with clinical relevance associated with the disease.

A phase 2 study of three low-dose intensity subcutaneous bortezomib regimens in elderly frail patients with untreated multiple myeloma.

This phase 2 trial evaluated three low-dose intensity subcutaneous bortezomib-based treatments in patients ⩾75 years with newly diagnosed multiple myeloma (MM). Patients received subcutaneous bortezomib plus oral prednisone (VP, N=51) or VP plus cyclophosphamide (VCP, N=51) or VP plus melphalan (VMP, N=50), followed by bortezomib maintenance, and half of the patients were frail. Response rate was 64% with VP, 67% with VCP and 86% with VMP, and very good partial response rate or better was 26%, 28.5% and 49%, respectively. Median progression-free survival was 14.0, 15.2 and 17.1 months, and 2-year OS was 60%, 70% and 76% in VP, VCP, VMP, respectively. At least one drug-related grade ⩾3 non-hematologic adverse event (AE) occurred in 22% of VP, 37% of VCP and 33% of VMP patients; the discontinuation rate for AEs was 12%, 14% and 20%, and the 6-month rate of toxicity-related deaths was 4%, 4% and 8%, respectively. The most common grade ⩾3 AEs included infections (8-20%), and constitutional (10-14%) and cardiovascular events (4-12%); peripheral neuropathy was limited (4-6%). Bortezomib maintenance was effective and feasible. VP, VCP and VMP regimens demonstrated no substantial difference. Yet, toxicity was higher with VMP, suggesting that a two-drug combination followed by maintenance should be preferred in frail patients.

CD56 expression is an indicator of poor clinical outcome in patients with acute promyelocytic leukemia treated with simultaneous all-trans-retinoic acid and chemotherapy.

PURPOSE: Preliminary reports suggest that leukemic cell expression of CD56, a neural cell adhesion molecule, is associated with adverse clinical outcome in either acute myeloid leukemia with t(8;21) or acute promyelocytic leukemia (APL). We investigated the prognostic relevance of CD56 in a series of patients with APL who were treated homogeneously with all-trans-retinoic acid (ATRA) and chemotherapy. PATIENTS AND METHODS: Clinicobiologic presenting features and therapeutic results were analyzed in a series of 100 patients with genetically proven APL who were treated, according to the example of the Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto multicenter trial, with ATRA plus idarubicin (AIDA) and for whom data on CD56 expression were available at diagnosis. RESULTS: Fifteen patients (15%) showed expression of CD56 in greater than or equal to 20% blasts at diagnosis and were considered as CD56(+). No differences were found regarding age, sex, WBC and platelet counts, incidence of coagulopathy, hemoglobin and fibrinogen levels, promyelocytic leukemia/retinoic acid receptor (PML/RAR) alpha fusion type, or complete remission (CR) rate in the comparison of the CD56(+) and CD56(-) populations. Conversely, compared with patients who were CD56(-), patients with CD56(+) APL had shorter CR duration (P =.04) and overall survival (P =.002). In the multivariate analysis, CD56 positivity and initial WBC count greater than 10 x 10(9) cells/L retained statistical significance in overall survival (P =.04 and P =.02, respectively). CONCLUSION: The expression of CD56 is significantly associated with inferior CR duration and survival in patients with APL who were treated with modern frontline treatment that included ATRA and simultaneous chemotherapy. Combined with other well-established prognostic factors such as WBC count, CD56 expression at diagnosis might be used to build prognostic scores for risk-adapted therapy in APL.

Modulation of purine analogs- and chlorambucil-induced cytotoxicity by alpha-interferon and interleukin-2 in chronic lymphocytic leukemia.

The decrease in cell viability observed in vitro from the effect of chlorambucil (CLB), fludarabine (FAMP) and 2-chlorodeoxy-adenosine (CDA) on peripheral lymphocytes from 49 untreated CLL patients was investigated by the MTT colorimetric assay. The effects of recombinant-interleukin (r-IL)-2 and alpha-interferon (alpha-IFN) on drug-induced cell death were evaluated. r-IL-2 significantly increased in vitro resistance to CLB, while purine analog cytotoxicity was slightly reduced by the cytokine. The potential in vivo significance of r-IL-2, acting as a survival signal on CLB-induced cell death, is supported by the correlation between the lowest IL-2 serum levels, the highest in vitro sensitivity to CLB and a major clinical response after CLB treatment in six out of eight CLL patients. Using 25 samples, alpha-IFN enabled CLL cells to increase resistance to CLB, CDA and FAMP in 14, eight and seven samples, respectively; conversely, alpha-IFN showed a synergism with both CLB and FAMP in six samples and with CDA in four. These results correlate with immunoenzymatic assay data showing that alpha-IFN either up- or down-regulates tumor necrosis factor and IL-1 levels in supernatants of some CLL samples. Apparently, alpha-IFN plays a dual role in regulating drug-induced cell death, while IL-2 seems to solely favor cell survival in CLL.

Alpha 2-interferon in B-cell chronic lymphocytic leukemia: clinical response, serum cytokine levels, and immunophenotype modulation.

Fifteen patients with B-cell chronic lymphocytic leukemia (B-CLL) have been treated with alpha 2b-interferon (alpha IFN) for one year (3 mega units subcutaneously three times a week). The hematological response and the modulation of immunophenotype, serum levels of soluble interleukin-2 receptor (sIL-2R) and tumour necrosis factor (TNF) have been monitored. Hematologically 67% of cases were classified as responders, although no complete responses were observed; three cases progressed during treatment, and two patients showed stable disease. Both peripheral lymphocytes and CD24+ cell absolute number significantly decreased after twelve months of IFN treatment (40.7 +/- 17 x 10(9)/l versus 15.8 +/- 6 x 10(9)/l, mean values +/- sd, p < 0.01, and 30.4 +/- 5.5 x 10(9)/l versus 8.1 +/- 2.8 x 10(9)/l, p < 0.05, respectively), while CD24+ cell percentage did not change (72.1% +/- 4.6 versus 67.5% +/- 8.8, p not significant). In the majority of cases myelomonocytic markers (CD11c, CD14, CD11b) transitorily decreased during the treatment. Serum sIL-2R levels, elevated in all cases before IFN treatment, increased in responders. Serum TNF levels decreased in patients showing high values before the treatment. The explanation of these findings and their possible implication are discussed.

Analysis of surface antigen profile, TdT expression, and T cell receptor gene rearrangement for maturational staging of leukemic T cells: a pediatric oncology group study.

By using monoclonal antibodies specific for T lineage surface antigens, neoplastic T cells from 53 children with T cell acute lymphoblastic leukemia and T cell non-Hodgkin's lymphoma were analyzed and assigned to phenotypically defined stages of T cell maturation. Cells were also analyzed for T cell antigen receptor beta-chain gene and immunoglobulin heavy and light chain gene rearrangements. Clonal rearrangements of T cell antigen receptor beta-chain gene and a germ-line configuration of the immunoglobulin genes were found in cells from all cases. The expression of the terminal deoxynucleotidyl transferase (TdT) in leukemic T cells was studied by both qualitative immunofluorescence and quantitative enzyme immunoassay, and the level of TdT expression was correlated with maturational stages. Lymphoblasts classified as prethymic (3 patients) did not express detectable TdT. In contrast, cells from approximately 60% of the patients with early (15 patients) or intermediate (19 patients) thymocytic phenotypes and approximately 40% of the patients with mature thymocytic phenotype (16 patients) were positive for TdT. Thus, in these leukemic clones TdT was randomly expressed and showed no correlation with maturational stage.

Diagnostic and prognostic role of PET/CT in patients with chronic lymphocytic leukemia and progressive disease.

In order to evaluate the predictive value of positron emission tomography-computed tomography (PET/CT) in discriminating the presence of a Richter's syndrome (RS) or a second malignancy (SM), as well as to evaluate its prognostic value in patients with chronic lymphocytic leukemia (CLL), we retrospectively analyzed the data of 90 patients who, in the suspicion of a RS or a SM, underwent PET/CT followed by the biopsy of the involved tissue. The median maximum Standardized Uptake Value (SUV max) in the presence of a CLL/small lymphocytic lymphoma, a diffuse large B-cell lymphoma (DLBCL), a Hodgkin lymphoma (HL), a SM were 3.5, 14.6, 7.0 and 6.3, respectively (P ⩽ 0.0001). A SUV max cutoff value ⩾ 5 showed a sensitivity, specificity, positive and negative predictive values of 88.2, 71.2, 51.3 and 94%, respectively, for the presence of a more aggressive disease (DLBCL, HL and SM). A SUV max ⩾ 5 identified also a subset of treatment naive patients with an inferior progression-free survival (P = 0.011) and overall survival (P = 0.067). These findings suggest that PET/CT may helpfully integrate the biologically-based prognostic stratification of CLL. Prospective clinical trials including larger cohorts of patients are needed to conclusively define the role and prognostic impact of PET/CT in the routine management of CLL patients.

Multilineage cell involvement in Ph1-negative, bcr-negative chronic myeloid leukemia.

We report a case of Ph1-negative, bcr-negative CML-BC, in which the primary leukemic cells displayed T-related antigens (CD7, CD4) in addition to HLA-DR and CD25 determinants. No B-lymphoid, myeloid and megakaryoblastic surface antigens were detected. In spite of this phenotype, DNA analysis revealed a germ-line configuration of the T-cell receptor beta chain gene region. Moreover, in-vitro culture studies demonstrated a proliferative response of the blast cell population to natural and recombinant myeloid-related factors, while no proliferative signal was observed in the presence of IL-2. The myeloid lineage was further demonstrated by the expression of myeloid-associated antigens on cultured blast cells, which still retained the CD7 antigen. Finally, cytogenetic analysis revealed a monosomy 7 which is usually associated with a stem cell leukemia. These results support the hypothesis that Ph1-negative, bcr-negative CML is characterized by the involvement of a multipotent stem cell capable of multilineage expression and indicate that differentiative and proliferative assays provide a further tool towards a more precise recognition of hematological disorders of uncertain origin.

Peripheral blood CD38 expression predicts survival in B-cell chronic lymphocytic leukemia.

CD38 expression was investigated in 161 untreated patients with B-cell chronic lymphocytic leukemia (B-CLL). A score system, devised ad hoc by integrating the percentage and the mean fluorescence intensity (MFI) values of CD38(+) cells, indicated that B-CLL patients with a CD38 score < or =3 are characterized by a significantly longer survival compared to those with a CD38 score >3 (P=0.0026). Thirty-seven percent of patients with a CD38 score < or =3 and 58% of those with a score >3 were dead at 10 years. Multivariate analysis indicates that only the CD38 score successfully predicts survival (P=0.0028), with an estimated 3.8-fold greater risk of death for those cases with CD38 score >3.

Failure of biliopancreatic diversion in Prader-Willi syndrome.

BACKGROUND: Prader-Willi syndrome (PWS) is the most common genetic obesity. Excessive weight gain follows failure-to-thrive in early infancy; in adolescents and young adults, excess body weight can exceed 100%. The hyperphagia associated with PWS is responsible for the early mortality. Dietary restriction, alone or combined with anorexic drugs, are ineffective to induce a permanent weight loss. Thus, surgical treatment of morbid obesity in PWS has been attempted, but gastric restrictive operations are unable to produce stable weight loss. In a small number of patients, favorable results have been reported with biliopancreatic diversion (BPD). CASE REPORT: A 24-year-old woman with PWS, Pickwickian, at age 21 weighed 80 kg (BMI= 50) and underwent BPD. RESULTS: 3 years after the BPD she regained 21 of the 26 kg lost; somnolence and respiratory difficulties were the same as before surgery. The patient now presents severe reduction of bone mass density, hypochromic anemia, hypoproteinemia, and diarrhea associated with eating. CONCLUSION: The regain of weight following BPD suggests that this procedure alone is not adequate for long-term control of obesity in PWS.

Quantitative molecular evaluation in autotransplant programs for follicular lymphoma: efficacy of in vivo purging by Rituximab.

The main aim of this paper was to compare results of Genescan and real-time PCR methods in order to detect contamination in harvests from patients with follicular lymphoma. The secondary goal was to evaluate the efficacy of Rituximab as an in vivo purging agent. A total of 23 patients had been treated with CHOP followed by either high-dose therapy (12 patients) or high-dose plus Rituximab (11 patients), both followed by autologous transplantation. Results show that 86% of harvests from patients treated with Rituximab were PCR-negative compared to 14.3% from controls. Real-time PCR was more sensitive than Genescan PCR; quantitative analysis revealed a correlation between the amount of contamination in the harvests and relapse after transplantation. Whereas all patients reinfused with negative aphereses achieved complete remission and showed a significantly better 5-year PFS (100%) compared to those reinfused with contaminated samples (41%), a very low amount of contamination does not appear to negatively affect outcome, suggesting that determination of a cutoff in the contamination level of harvests could be useful. Results suggest that real-time PCR is superior to Genescan PCR to select transplantable harvests and confirm the ability of Rituximab as an in vivo purging tool for follicular lymphoma.