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Patients with acute myeloid leukemia (AML) often achieve remission after allogeneic hematopoietic cell transplantation (allo-HCT) but subsequently die of relapse driven by leukemia cells resistant to elimination by allogeneic T cells based on decreased major histocompatibility complex II (MHC-II) expression and apoptosis resistance. Here we demonstrate that mouse-double-minute-2 (MDM2) inhibition can counteract immune evasion of AML. MDM2 inhibition induced MHC class I and II expression in murine and human AML cells. Using xenografts of human AML and syngeneic mouse models of leukemia, we show that MDM2 inhibition enhanced cytotoxicity against leukemia cells and improved survival. MDM2 inhibition also led to increases in tumor necrosis factor-related apoptosis-inducing ligand receptor-1 and -2 (TRAIL-R1/2) on leukemia cells and higher frequencies of CD8+CD27lowPD-1lowTIM-3low T cells, with features of cytotoxicity (perforin+CD107a+TRAIL+) and longevity (bcl-2+IL-7R+). CD8+ T cells isolated from leukemia-bearing MDM2 inhibitor-treated allo-HCT recipients exhibited higher glycolytic activity and enrichment for nucleotides and their precursors compared with vehicle control subjects. T cells isolated from MDM2 inhibitor-treated AML-bearing mice eradicated leukemia in secondary AML-bearing recipients. Mechanistically, the MDM2 inhibitor-mediated effects were p53-dependent because p53 knockdown abolished TRAIL-R1/2 and MHC-II upregulation, whereas p53 binding to TRAILR1/2 promotors increased upon MDM2 inhibition. The observations in the mouse models were complemented by data from human individuals. Patient-derived AML cells exhibited increased TRAIL-R1/2 and MHC-II expression on MDM2 inhibition. In summary, we identified a targetable vulnerability of AML cells to allogeneic T-cell–mediated cytotoxicity through the restoration of p53-dependent TRAIL-R1/2 and MHC-II production via MDM2 inhibition.

Common variable immunodeficiency (CVID) is a disease characterized by increased susceptibility to infections, hypogammaglobulinemia, and immune dysregulation. Although CVID is thought to be a disorder of the peripheral B-cell compartment, in 25% of patients, early B-cell development in the bone marrow is impaired. Because poor B-cell reconstitution after hematopoietic stem cell transplantation has been observed, we hypothesized that in some patients the bone marrow environment is not permissive to B-cell development. Studying the differentiation dynamics of bone marrow-derived CD34+ cells into immature B cells in vitro allowed us to distinguish patients with B-cell intrinsic defects and patients with a nonpermissive bone marrow environment. In the former, immature B cells did not develop and in the latter CD34+ cells differentiated into immature cells in vitro, but less efficiently in vivo. In a further group of patients, the uncommitted precursors were unable to support the constant development of B cells in vitro, indicating a possible low frequency or exhaustion of the precursor population. Hematopoietic stem cell transplantation would result in normal B-cell repopulation in case of intrinsic B-cell defect, but in defective B-cell repopulation in a nonpermissive environment. Our study points to the importance of the bone marrow niche in the pathogenesis of CVID.

Waldenström Macroglobulinaemia (WM) is an indolent lymphoma still primarily managed with chemo-immunotherapy, which remains a key first-line treatment option, although recently BTKIs have emerged as potential therapies for untreated patients.

Fas is a transmembrane receptor involved in the maintenance of tolerance and immune homeostasis. In murine models, it has been shown to be essential for deletion of autoreactive B cells in the germinal center. The role of Fas in human B-cell selection and in development of autoimmunity in patients carrying FAS mutations is unclear. We analyzed patients with either a somatic FAS mutation or a germline FAS mutation and somatic loss-of-heterozygosity, which allows comparing the fate of B cells with impaired vs normal Fas signaling within the same individual. Class-switched memory B cells showed: accumulation of FAS-mutated B cells; failure to enrich single V, D, J genes and single V-D, D-J gene combinations of the B-cell receptor variable region; increased frequency of variable regions with higher content of positively charged amino acids; and longer CDR3 and maintenance of polyreactive specificities. Importantly, Fas-deficient switched memory B cells showed increased rates of somatic hypermutation. Our data uncover a defect in B-cell selection in patients with FAS mutations, which has implications for the understanding of the pathogenesis of autoimmunity and lymphomagenesis of autoimmune lymphoproliferative syndrome.

1.IL-7 induces a strong proliferative burst in early human B-cell progenitors, but has a limited role in the prevention of cell death.2.IL-7 enhances BACH2, EBF1, and PAX5expression in early B-cell progenitors, which specify and commit early progenitors to the B-cell fate.

Nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme in nicotinamide adenine dinucleotide biosynthesis. In the extracellular compartment, it exhibits cytokine-/adipokinelike properties, suggesting that it stands at the crossroad between metabolism and inflammation. Here we show that both intracellular and extracellular NAMPT levels are increased in cells and plasma of chronic lymphocytic leukemia (CLL) patients. The extracellular form (eNAMPT) is produced by CLL lymphocytes upon B-cell receptor, Toll-like receptor, and nuclear factor κB (NF-κB) signaling pathway activation. eNAMPT is important for differentiation of resting monocytes, polarizing them toward tumor-supporting M2 macrophages. These cells express high levels of CD163, CD206, and indoleamine 2,3-dioxygenase and secrete immunosuppressive (interleukin [IL] 10, CC chemokine ligand 18) and tumor-promoting (IL-6, IL-8) cytokines. NAMPT-primed M2 macrophages activate extracellular-regulated kinase 1/2, signal transducer and activator of transcription 3, and NF-κB signaling; promote leukemic cell survival; and reduce T-cell responses. These effects are independent of the enzymatic activity of NAMPT, as inferred from the use of an enzymatically inactive mutant. Overall, these results reveal that eNAMPT is a critical element in the induction of an immunosuppressive and tumor-promoting microenvironment of CLL.

Autoimmune lymphoproliferative syndrome (ALPS) caused by impaired FAS-mediated apoptosis of lymphocytes is characterized by lymphoproliferation, autoimmunity, but also an increased risk of invasive bacterial infection, notably following splenectomy. We surveyed a cohort of 100 ALPS patients (including 33 splenectomized) and found that 12 (10 splenectomized) had experienced 23 invasive bacterial infections mainly caused by Streptococcus pneumoniae. This vulnerability was associated with evidence of defective B-cell function characterized by low serum immunoglobulin (Ig) M, low IgM antibody production in response to S pneumoniae following nonconjugated immunization, and low blood memory B-cells counts (including marginal zone [MZ] B-cell counts). This immunodeficiency strongly correlated with intensity of lymphoproliferation. Spleen sections from 9 ALPS patients revealed double-negative T-cell (DN-T) infiltration of the MZ, which was depleted of B cells. MZ in ALPS patients contained an abnormally thick layer of MAdCAM-1(+) stromal cells and an excess of DN-Ts. DN-Ts were shown to express MAdCAM-1 ligand, the α4β7 integrin. These observations suggest that accumulating DN-Ts are trapped within stromal cell meshwork and interfere with correct localization of MZ B cells. Similar observations were made in spleens of fas-deficient mice. Our data revealed an unexpected mechanism by which ALPS results in anti-polysaccharide IgM antibody production–specific defect. Splenectomy should be avoided.

The somatically acquired V600E mutation of the BRAF gene has been recently described as a molecular marker of hairy cell leukemia (HCL). We developed an allele-specific PCR for this mutation and studied 62 patients with HCL, 1 with HCL variant, 91 with splenic marginal zone lymphoma, 29 with Waldenström macroglobulinemia, and 57 with B-cell chronic lymphoproliferative disorders. The BRAF V600E mutation was detected in all HCL cases and in only 2 of the remaining 178 patients. These 2 subjects had B-cell chronic lymphoproliferative disorders that did not fulfill the diagnostic criteria for HCL. Despite the positive PCR finding, the mutation could not be detected by Sanger sequencing in these 2 cases, suggesting that it was associated with a small subclone. We conclude that the BRAF V600E mutation is present in all patients with HCL and that, in combination with clinical and morphologic features, represents a reliable molecular marker for this condition.

The somatically acquired V600E mutation of the BRAFgene has been recently described as a molecular marker of hairy cell leukemia (HCL). We developed an allele-specific PCR for this mutation and studied 62 patients with HCL, 1 with HCL variant, 91 with splenic marginal zone lymphoma, 29 with Waldenström macroglobulinemia, and 57 with B-cell chronic lymphoproliferative disorders. The BRAFV600E mutation was detected in all HCL cases and in only 2 of the remaining 178 patients. These 2 subjects had B-cell chronic lymphoproliferative disorders that did not fulfill the diagnostic criteria for HCL. Despite the positive PCR finding, the mutation could not be detected by Sanger sequencing in these 2 cases, suggesting that it was associated with a small subclone. We conclude that the BRAFV600E mutation is present in all patients with HCL and that, in combination with clinical and morphologic features, represents a reliable molecular marker for this condition.

In common variable immunodeficiency (CVID) defects in early stages of B-cell development, bone marrow (BM) plasma cells and T lymphocytes have not been studied systematically. Here we report the first morphologic and flow cytometric study of B- and T-cell populations in CVID BM biopsies and aspirates. Whereas the hematopoietic compartment showed no major lineage abnormalities, analysis of the lymphoid compartment exhibited major pathologic alterations. In 94% of the patients, BM plasma cells were either absent or significantly reduced and correlated with serum immunoglobulin G levels. Biopsies from CVID patients had significantly more diffuse and nodular CD3+T lymphocyte infiltrates than biopsies from controls. These infiltrates correlated with autoimmune cytopenia but not with other clinical symptoms or with disease duration and peripheral B-cell counts. Nodular T-cell infiltrates correlated significantly with circulating CD4+CD45R0+memory T cells, elevated soluble IL2-receptor and neopterin serum levels indicating an activated T-cell compartment in most patients. Nine of 25 patients had a partial block in B-cell development at the pre-B-I to pre-B-II stage. Because the developmental block correlates with lower transitional and mature B-cell counts in the periphery, we propose that these patients might form a new subgroup of CVID patients.

Integration of retroviral vectors in the human genome follows nonrandom patterns that favor insertional deregulation of gene expression and increase the risk of their use in clinical gene therapy. The molecular basis of retroviral target site selection is still poorly understood. We used deep sequencing technology to build genomewide, high-definition maps of > 60 000 integration sites of Moloney murine leukemia virus (MLV)– and HIV-based retroviral vectors in the genome of human CD34+multipotent hematopoietic progenitor cells (HPCs) and used gene expression profiling, chromatin immunoprecipitation, and bioinformatics to associate integration to genetic and epigenetic features of the HPC genome. Clusters of recurrent MLV integrations identify regulatory elements (alternative promoters, enhancers, evolutionarily conserved noncoding regions) within or around protein-coding genes and microRNAs with crucial functions in HPC growth and differentiation, bearing epigenetic marks of active or poised transcription (H3K4me1, H3K4me2, H3K4me3, H3K9Ac, Pol II) and specialized chromatin configurations (H2A.Z). Overall, we mapped 3500 high-frequency integration clusters, which represent a new resource for the identification of transcriptionally active regulatory elements. High-definition MLV integration maps provide a rational basis for predicting genotoxic risks in gene therapy and a new tool for genomewide identification of promoters and regulatory elements controlling hematopoietic stem and progenitor cell functions.

Previous observational studies suggest that rituximab may be useful in the treatment of primary immune thrombocytopenia (ITP). This randomized trial investigated rituximab efficacy in previously untreated adult ITP patients with a platelet count of 20 × 109/L or less. One hundred three patients were randomly assigned to receive 40 mg/d dexamethasone for 4 days with or without 375 mg/m2 rituximab weekly for 4 weeks. Patients who were refractory to dexamethasone alone received salvage therapy with dexamethasone plus rituximab. Sustained response (ie, platelet count ≥ 50 × 109/L at month 6 after treatment initiation), evaluable in 101 patients, was greater in patients treated with dexamethasone plus rituximab (n = 49) than in those treated with dexamethasone alone (n = 52; 63% vs 36%, P = .004, 95% confidence interval [95% CI], 0.079-0.455). Patients in the experimental arm showed increased incidences of grade 3 to 4 adverse events (10% vs 2%, P = .082, 95% CI, −0.010 to 0.175), but incidences of serious adverse events were similar in both arms (6% vs 2%, P = .284, 95% CI, −0.035 to 0.119). Dexamethasone plus rituximab was an effective salvage therapy in 56% of patients refractory to dexamethasone. The combination of dexamethasone and rituximab improved platelet counts compared with dexamethasone alone. Thus, combination therapy may represent an effective treatment option before splenectomy. This study is registered at http://clinicaltrials.gov as NCT00770562.

We describe a novel localization of C7 as a membrane-bound molecule on endothelial cells (ECs). Data obtained by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), Western blot analysis, Northern blot analysis, and mass spectrometry revealed that membrane-associated C7 (mC7) was indistinguishable from soluble C7 and was associated with vimentin on the cell surface. mC7 interacted with the other late complement components to form membrane-bound TCC (mTCC). Unlike the soluble SC5b-9, mTCC failed to stimulate ECs to express adhesion molecules, to secrete IL-8, and to induce albumin leakage through a monolayer of ECs, and more importantly protected ECs from the proinflammatory effect of SC5b-9. Our data disclose the possibility of a novel role of mC7 that acts as a trap for the late complement components to control excessive inflammation induced by SC5b-9.

Telomerase is considered a universal tumor-associated antigen (TAA) due to its high rate of expression by cancers (≈90%), and clinical trials are in progress to test the immunotherapeutical efficacy of antitelomerase immunization in patients with cancer. However, the data concerning frequency and functional activity of telomerase-specific cytotoxic T lymphocytes (CTLs) in patients with cancer are few and conflicting, although their knowledge would be mandatory to predict the efficacy of telomerase-specific immunotherapy in selected patients. We performed this study to analyze frequency and cytolytic function of circulating CD8+T lymphocytes specific for the p540 telomerase peptide in a series of human leukocyte antigen (HLA)–A2+cancer patients. The results show that most patients with cancer have circulating telomerase-specific CD8+T lymphocytes, but a high frequency of telomerase-specific CTLs are present only in a fraction of them. Furthermore, CTL lines able to kill telomerase-positive tumor cells, including autologous cancer cells, can be expanded ex vivo from some, but not all, patients with cancer. In conclusion, the results of the study support the development of clinical protocols using telomerase peptides as an immunizing agent. However, they underline the necessity to study single patients immunologically before undergoing vaccination, to select the patients adequately, and to eventually adapt the immunization schedule to the patient's immunologic status.

Telomerase is considered a universal tumor-associated antigen (TAA) due to its high rate of expression by cancers (≈90%), and clinical trials are in progress to test the immunotherapeutical efficacy of antitelomerase immunization in patients with cancer. However, the data concerning frequency and functional activity of telomerase-specific cytotoxic T lymphocytes (CTLs) in patients with cancer are few and conflicting, although their knowledge would be mandatory to predict the efficacy of telomerase-specific immunotherapy in selected patients. We performed this study to analyze frequency and cytolytic function of circulating CD8+ T lymphocytes specific for the p540 telomerase peptide in a series of human leukocyte antigen (HLA)–A2+ cancer patients. The results show that most patients with cancer have circulating telomerase-specific CD8+ T lymphocytes, but a high frequency of telomerase-specific CTLs are present only in a fraction of them. Furthermore, CTL lines able to kill telomerase-positive tumor cells, including autologous cancer cells, can be expanded ex vivo from some, but not all, patients with cancer. In conclusion, the results of the study support the development of clinical protocols using telomerase peptides as an immunizing agent. However, they underline the necessity to study single patients immunologically before undergoing vaccination, to select the patients adequately, and to eventually adapt the immunization schedule to the patient's immunologic status.

The development of multiple myeloma (MM) bone disease is mediated by increased number and activity of osteoclasts (OCs). Using an in vitro osteoclastogenesis model consisting of unstimulated and unfractionated peripheral blood mononuclear cells (PBMCs) from patients with MM, we showed that T cells support the formation of OCs with longer survival. Different from T-cell–depleted MM PBMC cultures, exogenous macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL) were necessary for the formation of OCs; however, they did not exhibit longer survival. We found up-regulated production of RANKL, osteoprotegerin (OPG), and TNF-related apoptosis-inducing ligand (TRAIL) by fresh MM T cells. Despite high OPG levels, the persistence of osteoclastogenesis can be related to the formation of the OPG/TRAIL complex demonstrated by immunoprecipitation experiments and the addition of anti-TRAIL antibody which decreases OC formation. OCs overexpressed TRAIL decoy receptor DcR2 in the presence of MM T cells and death receptor DR4 in T-cell–depleted cultures. In addition, increased Bcl-2/Bax (B-cell lymphoma-2/Bcl2-associated protein X) ratio, following Bcl-2 up-regulation, was detected in OCs generated in the presence of T cells. Our results highlight that MM T cells support OC formation and survival, possibly involving OPG/TRAIL interaction and unbalanced OC expression of TRAIL death and decoy receptors.

Eighty-two patients with advanced multiple myeloma (MM) were enrolled in 2 sequential clinical studies of 1 or 2 courses of myeloablative therapy with stem cell support. Conditioning regimens consisted of high-dose melphalan (MEL) with or without total body irradiation (TX1?=?35) and MEL as the first preparative regimen, followed within 6 months by busulfan and melphalan (TX2?=?47). On the basis of adequate stem cell harvest, 31 patients (TX1?=?13; TX2?=?18) were transplanted with highly purified CD34+ cells. Positively selected stem cells did not adversely affect hematopoietic reconstitution compared with unmanipulated peripheral blood stem cell. Overall, the complete remission (CR) rate of evaluative patients was 13.8% and 41% for single and double autotransplant, respectively (P?=?.04). Moreover, 3 patients undergoing TX2 achieved molecular remission and 2 remain PCR-negative after 36 and 24 months from autograft. The median event-free survival (EFS) durations for TX1 and TX2 were 17 and 35 months, respectively (P?=?.03). Actuarial 3-year overall survival for patients treated with 1 or 2 transplants are 76% and 92%, respectively (P?=?NS). On multivariate analysis, superior EFS was associated with low ß2 microglobulin (ß2-M) level at diagnosis and TX2, whereas overall survival was correlated with ß2-M. Positive selection of CD34+ cells did not influence the achievement of clinical or molecular CR, as well as remission duration or survival of MM patients. Thus, whereas multiple cycles of high-dose therapy may be beneficial for patients with myeloma, the clinical impact of tumor cell purging remains highly questionable.

Introduction.Monoclonal Gammopathy of Undetermined Significance (MGUS) is a pre-malignant plasma cell disorder reported in approximately 3% of individuals aged > 50 years, characterized by a low risk (about 1% per year) of evolution into “overt” myeloma or other lymphoproliferative diseases. It is classified as IgM-MGUS (15%) and non-IgM-MGUS (80-85%). MGUS is usually asymptomatic, but a higher risk of deep venous thrombosis and infection has been reported. In March 2020, “Coronavirus Disease 2019” (COVID-19) outbreak has been declared a pandemic by the World Health Organization. Regarding outcome of COVID-19 in patients with plasma cell dyscrasia, many papers have been published about multiple myeloma (MM), reporting a higher fatality rate respect to general population, while few data are available about the outcome of SARS-CoV-2 infection in patients with MGUS. Methods.We collected clinical data on MGUS Apulian patients with SARS- CoV-2 infection, tested by RT-PCR on nasopharyngeal swabs between March 1st, 2020 and April 30st, 2021. Among 1454 MGUS patients followed at our center, 91 were found SARS-CoV-2 positive, enrolled in this observational, retrospective study and compared with 182 age and sex-matched normal controls. Clinical data collected regarded: symptoms, hospitalization, hospitalization in intensive care unit, death. Calculations were carried out using Stata MP17. Results.Mean age of whole group (n. 273) was 65,3+/-13,3 years (range: 29-89), with no statistically-significant differences (p=0,734) observed between MGUS-group (65,6+/-13,3; range: 29-89 years) and controls-group (65,2+/- 13,4; range: 29-89 years). Mean number of comorbidities in the whole group was 1,2+/-1,2 (range: 0-5) and no statistically-significant differences (p=0,844) were found between MGUS-group (1,3+/-1,3; range: 0-5) and control group (1,2+/- 0,9; range: 0-3). About MGUS-subtypes, the most frequent was IgG-kappa (n=36; 39,6%), followed by IgG-lambda (n=27; 29,7%) and IgM-kappa (n=6; 6,6%). Regarding MGUS risk-stratification, application of Mayo Clinic model identified 22 patients (24,2%) with low risk, 22 (24,2%) with low-intermediate risk, and 3 (3,3%) with high-intermediate risk; in 44 patients (48,3%) this data was missing. Immunoparesis was present in 13 cases (14,3%) and absent in 55 (60,4%), missing in 23 (25,3%). No patient developed MM or a lymphoproliferative disease progression during and immediately after COVID-19. Rates of symptoms (59,3% vs 56%), hospitalization (20,9% vs 14,3%), hospitalization in intensive care unit (11% vs 8,8%) and death (8,8% vs 5,5%) were slightly higher in MGUS group than controls (Table 1), but these differences were not statistically significant. A statistically significant association (p<0,05), was observed between higher age and death in both groups. Lastly, incidence of SARS-CoV-2 infection in MGUS patients (6,2%) was not statistically significant different from that observed in the population of the Puglia region (5,8%) in the same period. Conclusions.To our knowledge, this report is the largest study of patients with MGUS and SARS-CoV-2 infection to date. In our study patients with MGUS did not show an increased incidence of this infection compared to the general population and did not appear to represent a risk factor for poor outcome in COVID-19.

Introduction

Patients with hematological malignancies (HM) undergoing hematopoietic stem cell transplantation (HSCT) have an increased vulnerability to SARS-Cov-2 (Sharma et al, Lancet Haematology 2020; Ljungman et al, Leukemia 2021), the reason why international guidelines strongly support the need for a protective vaccination for these subjects. The most relevant data currently available on the response to a complete anti-SARS-Cov-2 vaccination cycle in HM patients after HSCT refer to 314 patients reported in a Lithuanian national survey (Maneikis et al, Lancet Haematol 2021). In this study, the median titers of antibodies against SARS-Cov-2, determined 7-21 days after the second vaccination, were comparable to that of healthy controls (HC) in both autologous and allogeneic groups, with no patient found below the protective threshold of 50 arbitrary units (AU)/ml. Notably, the large majority of patients had received the transplant more than 1 year before vaccination.

Type II mixed cryoglobulinemia (MC) is an often progressive vasculitis characterized by circulating cold-precipitable proteins that usually consists of polyclonal IgG and monoclonal IgM kappa with rheumatoid factor (RF) activity. Its etiology is unknown, although recent evidence strongly suggests that hepatitis C virus (HCV) plays a major role. Plasmapheresis, corticosteroids, and cytotoxic drugs have been used in the therapy of MC patients. Recently, favorable results with recombinant interferon-alpha (rIFN alpha) have been reported. To further assess its effectiveness, we studied the effects of natural human interferon-alpha (nIFN alpha), alone and in combination with 6- methyl-prednisolone (PDN), in a prospective, randomized, controlled trial in patients with symptomatic MC. Sixty-five patients were enrolled onto the trial, 52 (80%) of whom presented serum anti-HCV antibodies and specific genomic RNA sequences. Fifteen patients received nIFN alpha (3 MU) intramuscularly (IM) three times weekly, whereas 17 patients also received 16 mg/d of PDN orally on non-IFN days. Moreover, 18 patients received 16 mg/d of PDN only, and 15 were untreated. Treatment was discontinued after 1 year and patients were monitored for 8 to 17 months (mean, 13). A complete response was achieved in eight of 15 patients (53.3%) treated with nIFN alpha and nine of 17 (52.9%) treated with nIFN alpha plus PDN, as compared with three of 18 patients (16.7%) who received PDN only (P < .05) and one of 15 (6.7%) untreated controls (P < .01). Partial response occurred in two of 15 (13.3%) patients treated with nIFN alpha, three of 17 (17.6%) who received nIFN alpha plus PDN, one of 18 (5.5%) who received PDN only, and one of 15 (6.7%) controls. A complete response in six patients (66.7%) was achieved within 3 months in the group that received nIFN alpha plus PDN, as compared with two patients (25%) of those who received nIFN alpha alone (P < .02). In anti-HCV-positive patients, the clinical response occurred in step with reduced or undetectable levels of HCV RNA and transaminase normalization. Quantification of circulating HCV RNA represented a good predictive response marker. The probability of relapse within 3 months after treatment was 100% (three of three patients) and 75% (six of eight patients), respectively, in patients who received PDN alone or nIFN alpha alone as compared with none of those who received nIFN alpha plus PDN (P < .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Type II mixed cryoglobulinemia (MC) is an often progressive vasculitis characterized by circulating cold-precipitable proteins that usually consists of polyclonal IgG and monoclonal IgMκ with rheumatoid factor (RF) activity. Its etiology is unknown, although recent evidence strongly suggests that hepatitis C virus (HCV) plays a major role. Plasmapheresis, corticosteroids, and cytotoxic drugs have been used in the therapy of MC patients. Recently, favorable results with recombinant interferon-alpha (rIFNα) have been reported. To further assess its effectiveness, we studied the effects of natural human interferon-α (nIFNα), alone and in combination with 6-methyl-prednisolone (PDN), in a prospective, randomized, controlled trial in patients with symptomatic MC. Sixty-five patients were enrolled onto the trial, 52 (80%) of whom presented serum anti-HCV antibodies and specific genomic RNA sequences. Fifteen patients received nIFNα (3 MU) intramuscularly (IM) three times weekly, whereas 17 patients also received 16 mg/d of PDN orally on non-IFN days. Moreover, 18 patients received 16 mg/d of PDN only, and 15 were untreated. Treatment was discontinued after 1 year and patients were monitored for 8 to 17 months (mean, 13). A complete response was achieved in eight of 15 patients (53.3%) treated with nIFNα and nine of 17 (52.9%) treated with nIFNα plus PDN, as compared with three of 18 patients (16.7%) who received PDN only (P < .05) and one of 15 (6.7%) untreated controls (P <.01). Partial response occurred in two of 15 (13.3%) patients treated with nIFNα, three of 17 (17.6%) who received nIFNα plus PDN, one of 18 (5.5%) who received PDN only, and one of 15 (6.7%) controls. A complete response in six patients (66.7%) was achieved within 3 months in the group that received nIFNα plus PDN, as compared with two patients (25%) of those who received nIFNα alone (P <.02). In anti-HCV-positive patients, the clinical response occurred in step with reduced or undetectable levels of HCV RNA and transaminase normalization. Quantification of circulating HCV RNA represented a good predictive response marker. The probability of relapse within 3 months after treatment was 100% (three of three patients) and 75% (six of eight patients), respectively, in patients who received PDN alone or nIFNα alone as compared with none of those who received nIFNα plus PDN (P < .001). Two of eight (25%) and three of nine (33.3%) patients who received nIFNα and nIFNα plus PDN, respectively, remained in remission throughout the follow-up period. nIFNα controls the activity of MC in more than 50% of patients. Its combination with PDN results in a more prompt response and delayed relapse; however, considering the increased viremia found with prednisone, the marginal effects of combined therapy do not warrant use of this protocol. In addition, relapse is common after 3 months of treatment withdrawal from both treatment modalities.

One advantage of the use of peripheral blood stem cells (PBSCs) over autologous bone marrow would be a reduced risk of tumor cell contamination. However, the level of neoplastic cells in the PB of multiple myeloma (MM) patients after mobilization protocols is poorly investigated. In this study, we evaluated PB samples from 27 pretreated MM patients after the administration of high dose cyclophosphamide (7 g/m2 or 4 g/m2) and granulocyte-colony stimulating factor for the detection of myeloma cells as well as hematopoietic progenitors. Plasma cells containing intracytoplasmic lg were counted by microscope immunofluorescence after incubation with appropriate antisera directed against light- and heavy-chain lg. Moreover, flow cytometry studies were performed to determine the presence of malignant B-lineage elements by using monoclonal antibodies against the CD19 antigen and the monotypic light chain. Before initiation of PBSC mobilization, circulating plasma cells were detected in all MM patients in a percentage ranging from 0.1% to 1.8% of the mononuclear cell fraction (mean value, 0.7% +/- 0.4% SD). In these patients, a higher absolute number of PB neoplastic cells was detected after chemotherapy and granulocyte colony-stimulating factor. Kinetic analysis showed a pattern of tumor cell mobilization similar to that of normal hematopoietic progenitors with a maximum peak falling within the optimal time period for the collection of PBSCs. The absolute number of plasma cells showed a 10 to 50-fold increase as compared with the baseline value. Apheresis products contained 0.7% +/- 0.2% SD of myeloma cells (range, 0.2% to 2.7%). Twenty-three MM patients were submitted to PBSC collection. In 10 patients, circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, were cryopreserved, and used to reconstitute bone marrow function after myeloablative therapy. The median purity of the enriched CD34+ cell population was 89.5% (range, 51% to 94%), with a 75-fold increase as compared with the pretreatment samples. The median overall recovery of CD34+ cells and colony-forming unit-granulocyte-macrophage was 58% (range, 33% to 95%) and 45% (range, 7% to 100%), respectively. Positive selection of CD34+ cells resulted in 2.5- to 3-log depletion of plasma cells and CD19+ B-lineage cells as determined by immunofluorescence studies, although DNA analysis of CDR III region of IgH gene showed the persistence of minimal residual disease in 5 of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (1,000 cGy) and highdose melphalan (140 mg/m2). They received a median of 4 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis; the median time to 0.5 x 10(9) neutrophils and to 20 and 50 x 10(9) platelets per liter of PB was 10, 11, and 12 days, respectively. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (n = 13) receiving unmanipulated PBSCs after the same pretransplant conditioning regimen. In summary, our data show the concomitant mobilization of tumor cells and hematopoietic progenitors in the PB of MM patients. Positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3-log and provides a cell suspension capable of restoring a normal hematopoiesis after a total body irradiation-containing conditioning regimen.

No relevant conflicts of interest to declare.

Background.Waldenström Macroglobulinemia (WM) is a rare indolent lymphoma typical of the elderly population, with a median age at diagnosis of 65-70 years and median overall survival of approximately 10 years. Age is the most important prognostic factor in WM, and unrelated mortality significantly impacts survival in elderly patients. The past two decades have witnessed important treatment advances in WM, with the introduction of anti-CD20 monoclonal antibodies in the early 2000s and of ibrutinib in more recent years.

Background.High rates of response and minimal residual disease (MRD) negativity have been reported with the use of novel treatment options in multiple myeloma (MM) patients (pts) eligible for autologous stem-cell transplantation (ASCT). Despite very promising results, there is still a proportion of pts who do not respond to therapy or relapse early. This represents an unmet medical need.

Lund Winter: CaDo Biotechnology IvS: Employment. Stegmaier:Novartis: Research Funding; Rigel Pharmaceuticals: Consultancy. Dalby-Brown:CaDo Biotechnology IvS: Employment.

Gay: Roche: Other: Advisory Board; Seattle Genetics: Other: Advisory Board; Bristol-Myers Squibb: Honoraria; Janssen: Honoraria; Celgene: Honoraria, Other: Advisory Board; Amgen: Honoraria; Takeda: Honoraria, Other: Advisory Board. Galli:Sigma-Tau: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Bristol-Myers Squibb: Honoraria. Belotti:Celgene: Other: Advisory Board; Amgen: Other: Advisory Board. Zamagni:BMS: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Angelucci:Novartis: Honoraria, Other: Chair Steering Committee TELESTO protocol in MDS; Celgene: Honoraria, Other: Chair DMC proptocol BELIEVE 1 and BELIVE 2 in Thalassemia; Vertex Pharmaceuticals Incorporated (MA) and CRISPR Therapeutics AG (CH): Other: Chair DMC CRISPR CAS9 in Hemoglobinopathies; Jazz Pharmaceuticals Italy: Other: Local (national) advisory board on AML; Roche Italia: Other: Local (national) advisory board on biosimilars. Annibali:Celgene; Takeda; Amgen, Janssen Cilag: Honoraria. Offidani:Amgen: Honoraria, Other: Advisory Board; Takeda: Honoraria, Other: Advisory Board; Janssen: Honoraria, Other: Advisory Board; Celgene: Honoraria, Other: Advisory Board; Bristol-Myers Squibb: Honoraria, Other: Advisory Board. Palumbo:Takeda: Employment. Musto:Amgen: Honoraria; BMS: Honoraria; Takeda: Honoraria; Janssen: Honoraria; Celgene: Honoraria. Cavo:GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees. Boccadoro:Bristol-Myers Squibb: Honoraria, Research Funding; Mundipharma: Research Funding; Sanofi: Honoraria, Research Funding; Celgene: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie: Honoraria.

Chodera: Schrödinger: Consultancy, Membership on an entity's Board of Directors or advisory committees.

Background:Transfusion therapy for severe chronic anemias is a major cause of iron overload. Patients with hemoglobin disorders are often transfused, either chronically or occasionally, and if iron overload is suspected, it is currently recommended they are subjected to so-called “iron studies” and determination of liver iron content (LIC) and heart T2* by magnetic resonance imaging (MRI). It remains common practice to request both laboratory and imaging tests, even for patients already undergoing iron chelation, despite the unreliability of laboratory markers such as ferritin in the presence of concurrent inflammatory conditions, which do not affect results from MRI scans. Since MRI is not widely available in most underdeveloped and developing countries, we aimed to assess the contribution of laboratory tests to the management of patients with hemoglobin disorders with iron overload by analyzing a cohort of patients who managed to undergo MRI during a period of limited access to MRI scans in our center.

Cavo: Bristol-Myers Squibb: Honoraria; Takeda: Honoraria; Celgene: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Amgen: Honoraria. Offidani:Janssen: Honoraria; Celgene: Honoraria, Research Funding. Boccadoro:Janssen: Honoraria, Research Funding; CELGENE: Honoraria, Research Funding; Mundipharma: Research Funding; Amgen: Honoraria, Research Funding; SANOFI: Honoraria, Research Funding; BMS: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Abbivie: Honoraria.

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No relevant conflicts of interest to declare.

No relevant conflicts of interest to declare.

No relevant conflicts of interest to declare.

Offidani: Mundipharma, Janssen: Honoraria. Off Label Use: Bendamustine. Corvatta:Janssen: Honoraria. Ballanti:Janssen: Honoraria. Brunori:Janssen: Honoraria.

Karthaus: Helsinn Healthcare: Honoraria. Off Label Use: NEPA is a combination antiemetic currently under FDA review. Aapro:Helsinn Healthcare: Consultancy, Honoraria. Rizzi:Helsinn Healthcare: Employment. Palmas:Helsinn Healthcare: Employment.

Cyclophosphamide (CTX), a commonly used alkylating agent in the treatment of hematological malignancies and solid tumor diseases, is a prodrug metabolized to its active metabolite primarily via CYP2B6 with minor contribution of CYP3A4. CTX is also converted to neurotoxic and inactive metabolites mainly via CYP3A4. NEPA is a unique fixed-dose antiemetic combination of netupitant (NETU), a highly-selective NK1receptor antagonist (RA) and palonosetron (PALO), a pharmacologically distinct 5-HT3RA. Superiority of NEPA over PALO in preventing chemotherapy-induced nausea and vomiting was recently demonstrated in solid tumors. Although no significant drug-drug interactions between NETU, a moderate CYP3A4 inhibitor, and CTX are expected, NEPA has the potential to impact CTX metabolism and CTX-related toxicities.

Multiple myeloma (MM)-bone disease occurs in 70% to 80% of patients at MM diagnosis, and up to 90% at relapse; skeletal related events cause high morbidity and mortality. MM-bone disease is mostly consisting of lytic lesions arising as a consequence of an unbalanced bone remodelling due to activation of osteoclasts (OCs), and inactivation of osteoblasts. Osteoclastogenesis may be under immunoregulation by T-cells through the production of receptor activator of NF-kB ligand (RANKL), that is the OC differentiating molecule.By means of an in vitro osteoclastogenesis model derived from peripheral blood mononuclear cells (PBMCs) of patients with MM-lytic bone disease, we purposed to evaluate OC formation and T-cell RANKL expression at diagnosis, and in the setting of frontline therapy.PB was taken by venipuncture from 18 patients (7 men and 11 women), aged from 63 to 84, diagnosed as having symptomatic MM by International Myeloma Working Group (IMWG) criteria. In all of them, lytic lesions were demonstrated by skeleton standard radiography, and in some cases by nuclear magnetic resonance (NMR) too. On the basis of patients’ age and fitness, initial standard therapy consisting of proteasome inhibitor (Bortezomib) associated with Melphalan and Prednisone (VMP) was administered for nine cycles. The therapy response was assessed according to IMWG criteria. The controls included PB collected from 20 healthy donors, matched for age and sex with the patients. Controls and patients gave their written informed consent to the study, that was approved by the local Ethical Committee and performed according to the Declaration of Helsinki. PB was taken from the patients at diagnosis, and following the fourth and the ninth VMP cycles, respectively. OCs were obtained from unfractionated PBMC cultures either stimulated or not with the exogenous pro-osteoclastogenic cytokines [macrophage-colony stimulating factor (M-CSF) and RANKL]. Mature OCs were identified as multinucleated tartrate-resistant acid phosphatase (TRAP) positive cells. Freshly isolated T-cells from patients’ and controls’ PBMCs were lysed and analyzed by Western Blotting to evaluate RANKL expression.Spontaneous osteoclastogenesis was demonstrated in the cultures derived from PBMCs isolated at diagnosis. With particular regard to the patients achieving a deep treatment response, at the end of the culture period we found that PBMCs formed few small-sized OCs, when cultured in the absence of M-CSF and RANKL. Moreover, fresh T-cells purified after four and nine VMP cycles expressed progressively lower RANKL levels than fresh T-cells purified at diagnosis. Otherwise the cultures derived from non-responsive patients’ PBMCs, collected during and after treatment respectively, showed in vitro spontaneous formation of numerous and large OCs, overlapping the results at diagnosis. Fresh T-cells purified during or after treatment expressed comparable or even higher RANKL levels respect to diagnosis.These findings show that in vitro spontaneous osteoclastogenesis and T-cell RANKL expression may be correlated with the response to treatment in patients with MM-lytic bone disease. However, further studies will be necessary to confirm these data, and to better translate them from a biologic to a clinical point of view.No relevant conflicts of interest to declare.

Diffuse large B-cell lymphoma (DLBCL) is the most frequently aggressive Non-Hodgkin's lymphoma (NHL). DLBCL first line therapy consists of R-CHOP regimen, which combines classical chemotherapeutical drugs and corticosteroids with Rituximab. Rituximab is a chimeric anti-CD20 monoclonal antibody which targets the CD20 surface antigen expressed on both normal and malignant B cells. Rituximab triggers antibody- and complement-dependent cytotoxicity, growth inhibition and apoptosis. Rituximab inhibits the expression of the anti-apoptotic proteins Bcl-2/Bcl-XL, down-modulating different survival pathways. Clusterin (CLU) is an ubiquitary protein involved in many physiological and pathological processes such as apoptosis and cancer. CLU has different transcriptional isoforms, which share exons from 2 to 9 but have a unique exon 1 and at least two protein forms: The cytoplasmatic precursor of about 60 kDa is secreted outside the cell after post-traslational modifications (sCLU), whereas a truncated protein (50–55 kDa) is produced only in particular conditions and localizes in the nucleus (nCLU). CLU expression is disregulated in almost all cancers and its role has been deeply investigated in solid tumors. Only limited information is currently available about its function in lymphomas.Toledo, a DLBCL-derived cell line and normal B lymphocytes were chosen as experimental models. B lymphocytes were purified and immuno-magnetically sorted from peripheral blood of 4 healthy volunteers. Toledo and B lymphocytes were treated with 10 or 100 μg/ml Rituximab or doxorubicin (from 0.05 to 1 μM) for 48 hours. Phenotype analysis was performed by flow cytometry; cell viability was assessed by Trypan blue exclusion; apoptosis was evaluated by Annexin V/propidium iodide. CLU expression and localization were evaluated by real time PCR, Western Blot (WB) and immunocytochemistry (ICC). Primers for the real time PCR were design in order to distinguish the unique exon 1 of each CLU transcriptional isoforms or exons common to all variants (CLU3-4).Rituximab treatment doesn't significantly inhibit Toledo proliferation and does not induce apoptosis despite the fact that these cells are CD20+. This suggests that Toledo are resistant to Rituximab. As expected, doxorubicin causes a marked growth inhibition by necrosis and apoptosis. Toledo cells have a very low basal level of the 60 kDa CLU protein form. Both Rituximab and doxorubicin up-regulate the 60 kDa form with 1 μM doxorubicin causing the most dramatic increase. The analysis of transcriptional isoforms by real-time PCR shows that CLU mRNA is almost undetectable in Toledo. CLU transcriptional variant 2 (CLU2) and regions common to all CLU transcripts (CLU3-4) are significantly up-regulated only after 1 μM doxorubicin but not after Rituximab. Fluorescence microscopy clearly shows a cytoplasmic localization of CLU under normal growth conditions. Interestingly, the treatment with both Rituximab and doxorubicin causes the appearance of a nuclear staining. This fact might be consistent with the onset of a process of cell death. 10 and 100 μg/ml Rituximab inhibits B lymphocytes cell survival in a dose-dependent manner (39.7% and 44% respectively after 48 hours). Interestingly, B lymphocytes clearly express high basal levels of the 60 kDa CLU and produce an additional form of about 55 kDa only after Rituximab but not after doxorubicin. Furthermore Rituximab-treated B lymphocytes display a Bcl-2 protein decrease while Toledo cells show high expression of Bcl-2 that doesn't seem to change in response to Rituximab.Toledo are resistant to Rituximab up to 100 μg/ml and express very low levels of CLU under normal growth conditions. 60 kDa CLU is partially up-regulated and Bcl-2 expression is not significantly affected by Rituximab treatment. Doxorubicin strongly up-regulates the 60 kDa CLU isoform. At the transcriptional level CLU2 shows the same expression profile of the 60 kDa protein form. On the contrary, Rituximab changes the CLU profile of responsive B lymphocytes in that leads to the appearance of a 55 kDa form that is not visible after doxorubicin treatment. Rituximab also causes a reduction in the expression of the antiapoptotic protein Bcl-2. The biological role of CLU during the response of peripheral B lymphocytes to Rituximab treatment is yet to be determined and is currently being investigated.No relevant conflicts of interest to declare.

Abstract 2031

No relevant conflicts of interest to declare.

Foa: Roche: Consultancy, Speakers Bureau. Cuneo:Roche: Consultancy, Speakers Bureau. Montillo:Roche: Membership on an entity's Board of Directors or advisory committees. Alietti:Roche: Employment. Runggaldier:Roche: Employment. Gamba:Roche Italia: Employment.

This 41 year-old woman presented in November 2008 with asymptomatic lymphocytosis, without any evidence of lymphadenopathy, splenomegaly or hepatomegaly. Laboratory data showed: Hb 12.9 g/dL, WBC count 16 × 109/L (62% lymphoid cells), and PLT count 283 × 109/L. On BM biopsy, an interstitial lymphoid infiltrate (60% of the whole cellularity) composed by small, lymphocyte/centrocyte-like cells was found. By immunohistochemistry, neoplastic cells showed expression of CD20, CD79a and cyclin-D1, but were uniformly negative for CD5, CD10, CD23, CD25 and DBA44, and annexin A1. At flow cytometry analysis, they were CD20 and FMC7 positive and CD10, CD38, CD5, CD23, CD11c, CD25, DBA44 and CD103 negative. FISH for t(11;14), performed for cyclin D1 expression, was negative. Immunoglobulin rearrangement was IGHV3-48*02, IGHD7-27*01 IGHJ4*02. So far, lymphocytosis has remained stable and the patient is regularly followed without any need for treatment.This 62 year-old male presented in 2006 with thrombocytopenia and splenomegaly, and was diagnosed with HCL was established in another hospital (no additional data are available). He was treated with cladribine with a partial response. In May 2008, we evaluated this patient in Pavia. The spleen was palpable 3 cm under the costal margin, and laboratory data showed: Hb 15.4 g/dL, WBC count 3.9 × 109/L, and PLT vount 95 × 109/L. BM biopsy showed a 20% lymphoid infiltrate with interstitial and sinusoidal pattern, composed by small to medium sized cells with evident nucleoli, resembling pro-lymphocytes. By immunohistochemistry, cells were positive for CD20 and negative for CD5, CD23, cyclin-D1, CD25, DBA44, and annexin A1. Flow cytometry demonstrated the expression of CD20, FMC7 and CD11c, partial expression (25%) of CD103, and negativity for CD5, CD10, CD38, CD23, DBA44, CD11c and CD25. This patient was asymptomatic and a watch-and wait-policy was adopted.These findings indicate that the allele-specific PCR we developed is able to detect the mutation in the bone marrow of all patients with HCL, and confirm that the BRAF V600E mutation is highly specific for HCL within mature B-cell neoplasms. Only 2/177 (1.1%) patients with lymphoid neoplasms other than HCL (2/57 or 3.5% of patients with B-CLPD) were positive for BRAF V600E. This is in agreement with a previous study that found BRAF mutations in 2.4% of patients with non-Hodgkin's lymphoma (Br J Cancer. 2003 Nov 17;89:1958–60). The detection of the BRAF V600E mutation in the clone (or, at least, in a subclone) of mature B-cell lymphoid neoplasms without typical HCL features might help to define their biology.No relevant conflicts of interest to declare.