Polycythemia vera and hydroxyurea resistance/intolerance: a monocentric retrospective analysis.

Hydroxyurea (HU) resistance or intolerance occurs in 15 to 24% of patients with polycythemia vera (PV). Resistance to HU is associated with a shortened life expectancy, intolerance has no prognostic value. We assessed the occurrence of HU resistance or intolerance comparing the original (ELNo) versus the modified European Leukemia Net (ELNm) criteria as applied in recent large clinical trials including PV patients. We retrospectively analyzed 106 patients with PV treated with HU at the University Hospitals of Leuven between 1990 and 2016 for occurrence of HU resistance/intolerance when using both ELNo as ELNm. After a mean duration of treatment of 5.1 years, when applying the ELNo 20.7% of patients had shown resistance or intolerance to HU in comparison to 39.6% when using the ELNm. When using the ELNo 4.7% of patients were resistant to HU versus 23.6% when applying the ELNm. In total, 16.0% of patients were HU intolerant. This rate was identical when using both ELNo and ELNm. 20.7% of PV patients were considered as HU-resistant or intolerant when using the original ELN criteria. However, when applying the modified ELN criteria 39.6% of PV patients were resistant or intolerant to HU. In our hands, no patient received a minimum dose of 2 g HU a day, as such the ELNm seem better adapted for daily clinical use. However, the prognostic value of HU-resistance in PV, when defined by the ELNm, still needs to be confirmed.

Myeloid-derived suppressor cells in lymphoma: The good, the bad and the ugly.

Lymphomas cause significant morbidity and mortality worldwide. A substantial number of patients ultimately relapse after standard treatment. However, the efficacy of these therapies can be counteracted by the patients' immune system, more specifically by myeloid-derived suppressor cells (MDSC). MDSC are a heterogeneous group of immature myeloid cells that suppress the innate and adaptive immune system via different mechanisms and accumulate under pathological conditions, such as cancer. MDSC play a role in the induction and progression of cancer and immune evasion. Increased numbers of MDSC have been reported in different lymphoma subtypes and are associated with a poor clinical outcome. This review aims to clarify the role of MDSC and their working mechanism in different lymphoma subtypes. Furthermore, the effect of MDSC on immunotherapies will be discussed.

Phase II study of copanlisib, a PI3K inhibitor, in relapsed or refractory, indolent or aggressive lymphoma.

BACKGROUND: Copanlisib is a pan-class I phosphatidylinositol 3-kinase inhibitor with predominant activity against the α- and δ-isoforms. PATIENTS AND METHODS: This phase II study evaluated the response rate of copanlisib administered intravenously on days 1, 8, and 15 of a 28-day cycle, in patients with indolent or aggressive malignant lymphoma. Archival tumor tissues were used for immunohistochemistry, gene-expression profiling, and mutation analysis. RESULTS: Thirty-three patients with indolent lymphoma and 51 with aggressive lymphoma received copanlisib. Follicular lymphoma (48.5%) and peripheral T-cell lymphoma (33.3%) were the most common histologic subtypes. Most patients (78.6%) had received prior rituximab and 54.8% were rituximab-refractory. Median duration of treatment was 23 and 8 weeks in the indolent and aggressive cohorts, respectively (overall range 2-138). Eighty patients were evaluated for efficacy. The objective response rate was 43.7% (14/32) in the indolent cohort and 27.1% (13/48) in the aggressive cohort; median progression-free survival was 294 days (range 0-874) and 70 days (range 0-897), respectively; median duration of response was 390 days (range 0-825) and 166 days (range 0-786), respectively. Common adverse events included hyperglycemia (57.1%; grade ≥3, 23.8%), hypertension (54.8%; grade ≥3, 40.5%), and diarrhea (40.5%; grade ≥3, 4.8%), all generally manageable. Neutropenia occurred in 28.6% of patients (grade 4, 11.9%). Molecular analyses showed enhanced antitumor activity in tumors with upregulated phosphatidylinositol 3-kinase pathway gene expression. CONCLUSION: Intravenous copanlisib demonstrated promising efficacy and manageable toxicity in heavily pretreated patients with various subtypes of indolent and aggressive malignant lymphoma. Subtype-specific studies of copanlisib in patients with follicular, peripheral T-cell, and mantle cell lymphomas are ongoing. This trial is registered with ClinicalTrials.gov number NCT01660451 (Part A).

EBV-Positive and EBV-Negative Posttransplant Diffuse Large B Cell Lymphomas Have Distinct Genomic and Transcriptomic Features.

The molecular pathogenesis of posttransplant diffuse large B cell lymphoma (PT-DLBCL) is largely unknown. We have recently shown that Epstein-Barr virus-positive (EBV(+)) and -negative (EBV(-)) PT-DLBCL have distinct gene expression profiles, and the transcriptomic profile of EBV(-) PT-DLBCL is similar to that of DLBCL in immunocompetent individuals (IC-DLBCL). To validate these observations at the genomic level, we performed array-comparative genome hybridization (aCGH) analysis of 21 EBV(+) PT-DLBCL, 6 EBV(-) PT-DLBCL, and 11 control IC-DLBCL, and subsequently combined genomic and transcriptomic data. The analysis showed that EBV(+) and EBV(-) PT-DLBCL have distinct aCGH profiles and shared only one recurrent imbalance. EBV(-) PT-DLBCL, however, displayed at least 10 aberrations recurrent in IC-DLBCL, among which characteristic gain of 3/3q and 18q, and loss of 6q23/TNFAIP3 as well as 9p21/CDKN2A. The most prevalent aberration in EBV(+) PT-DLBCL was gain/amplification of 9p24.1 targeting PDCD1LG2/PDL2. Our data indicate that the FOXP1 oncogene and the tumor suppressor CDKNA2 implicated in EBV(-) DLBCL, do not play a critical role in the pathogenesis of EBV(+) PT-DLBCL. Altogether, genomic profiling of PT-/IC-DLBCL confirms that EBV(-) and EBV(+) PT-DLBCL are distinct entities, while EBV(-) PT-DLBCL has features in common with IC-DLBCL. These findings support the hypothesis that EBV(-) PT-DLBCL are de novo lymphomas in transplant recipients.

Treatment with lenalidomide (Revlimid®), cyclophosphamide (Endoxan®) and prednisone (REP) in relapsed/refractory multiple myeloma patients: results of a single centre retrospective study.

Lenalidomide (Revlimid®) combined with intermittent dexamethasone (the RD regimen) is one of the current standards for treatment of patients with relapsed/refractory multiple myeloma (MM). However, since the disease in the majority of patients will become resistant to RD, or treatment with RD needs to be discontinued due to side effects, we evaluated the combination lenalidomide, low-dose oral cyclophosphamide, with prednisone (REP) in patients with relapsed/refractory MM previously exposed to RD. For this purpose, we performed a single centre retrospective study of the efficacy of REP in 19 patients with relapsed/refractory MM. Overall response rate (partial response or better) with REP was 68% compared with 83% with RD, but with a shorter time to response with the triplet REP. Time to progression after REP was 6 months. Overall the REP regimen was better tolerated compared to RD. We conclude that the REP regimen is an effective treatment regimen for patients with relapsed/refractory MM with good tolerance, warranting further exploration in prospective randomized trials.

Gene expression profiling reveals clear differences between EBV-positive and EBV-negative posttransplant lymphoproliferative disorders.

Posttransplant patients are at risk of developing a potentially life-threatening posttransplantation lymphoproliferative disorder (PTLD), most often of diffuse large B cell lymphoma (DLBCL) morphology and associated with Epstein-Barr Virus (EBV) infection. The aim of this study was to characterize the clinicopathological and molecular-genetic characteristics of posttransplant DLBCL and to elucidate whether EBV(+) and EBV(-) posttransplant DLBCL are biologically different. We performed gene expression profiling studies on 48 DLBCL of which 33 arose posttransplantation (PT-DLBCL; 72% EBV+) and 15 in immunocompetent hosts (IC-DLBCL; none EBV+). Unsupervised hierarchical analysis showed clustering of samples related to EBV-status rather than immune status. Except for decreased T cell signaling these cases were inseparable from EBV(-) IC-DLBCL. In contrast, a viral response signature clearly segregated EBV(+) PT-DLBCL from EBV(-) PT-DLBCL and IC-DLBCL cases that were intermixed. The broad EBV latency profile (LMP1+/EBNA2+) was expressed in 59% of EBV(+) PT-DLBCL and associated with a more elaborate inflammatory response compared to intermediate latency (LMP1+/EBNA2-). Inference analysis revealed a role for innate and tolerogenic immune responses (including VSIG4 and IDO1) in EBV(+) PT-DLBCL. In conclusion we can state that the EBV signature is the most determining factor in the pathogenesis of EBV(+) PT-DLBCL.

Rituximab in auto-immune haemolytic anaemia and immune thrombocytopenic purpura: a Belgian retrospective multicentric study.

OBJECTIVES: For better characterizing the effect of anti-CD20 therapy, we analysed the use of rituximab in Belgian patients experiencing auto-immune haemolytic anaemia (AIHA) and immune thrombocytopenic purpura (ITP). DESIGN: We performed a retrospective multicentric analysis of patients with AIHA and ITP treated with rituximab in Belgium. SETTING: Haematological departments were invited to fill in a questionnaire about patient and disease characteristics. SUBJECTS: All patients with AIHA and ITP, both primary and secondary to other diseases, who received one or more courses of rituximab during their disease course were included. Sixty-eight courses of rituximab in 53 patients with AIHA and 43 courses in 40 patients with ITP were analyzed. INTERVENTION: Response rates, duration of response and factors predictive for response were assessed. RESULTS: All patients were given rituximab after failing at least one previous line of treatment, including splenectomy in 19% and 72.5% of AIHA-patients and ITP-patients respectively. Overall response rates were 79.2% in AIHA and 70% in ITP, with a median follow-up since first rituximab administration of 15 months (range 0.5-62) in AIHA and 11 months (range 0-74) in ITP. Progression free survival at 1 and 2 years were 72% and 56% in AIHA and 70% and 44% in ITP. In this retrospective analysis we were not able to identify pretreatment characteristics predictive for response to rituximab. Nine patients with AIHA and three patients with ITP were given one or more additional courses of rituximab. Most of these patients, who had responded to a previous course, experienced a new response comparable to the previous one, both in terms of quality and of duration of response. Finally, the outcome of patients who failed to respond to rituximab therapy was poor both in terms of response to subsequent therapy and in terms of survival. CONCLUSIONS: This study confirms that rituximab induces responses in a majority of previously treated patients with AIHA and ITP. Response duration generally exceeds 1 year. Retreatment with rituximab in responding patients is most often successful. The outcome of patients who fail on rituximab is poor. We were not able to identify pretreatment patient characteristics predicting for response.

Stromal gene signatures in large-B-cell lymphomas.

BACKGROUND: The addition of rituximab to combination chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or R-CHOP, has significantly improved the survival of patients with diffuse large-B-cell lymphoma. Whether gene-expression signatures correlate with survival after treatment of diffuse large-B-cell lymphoma is unclear. METHODS: We profiled gene expression in pretreatment biopsy specimens from 181 patients with diffuse large-B-cell lymphoma who received CHOP and 233 patients with this disease who received R-CHOP. A multivariate gene-expression-based survival-predictor model derived from a training group was tested in a validation group. RESULTS: A multivariate model created from three gene-expression signatures--termed "germinal-center B-cell," "stromal-1," and "stromal-2"--predicted survival both in patients who received CHOP and patients who received R-CHOP. The prognostically favorable stromal-1 signature reflected extracellular-matrix deposition and histiocytic infiltration. By contrast, the prognostically unfavorable stromal-2 signature reflected tumor blood-vessel density. CONCLUSIONS: Survival after treatment of diffuse large-B-cell lymphoma is influenced by differences in immune cells, fibrosis, and angiogenesis in the tumor microenvironment.

Usefulness of FDG-PET to diagnose intravascular lymphoma with encephalopathy and renal involvement.

Intravascular lymphoma (IVL) is a rare subtype of extranodal diffuse large B-cell lymphoma. It is characterized by proliferation of neoplastic Lymphoid cells almost exclusively within the lumina of small blood vessels. It can affect virtually every organ system. Due to its rarity and its diverse and heterogeneous clinical presentation, diagnosis is difficult and often made post-mortem. When diagnosed early, it is, however, potentially treatable. We present a young woman with longstanding constitutional symptoms, positive antinuclear antibody, elevated LDH levels and rapidly progressive encephalopathy. FDG-PET scan showed intense uptake in the renal cortex, which prompted us to perform a kidney biopsy which was compatible with IVL. The value of PET in establishing the diagnosis of this rare disease will be discussed.

Achievement of optimal average relative dose intensity and correlation with survival in diffuse large B-cell lymphoma patients treated with CHOP.

The treatment of diffuse large B-cell lymphoma with chemotherapy was retrospectively evaluated in 348 patients who had received at least three cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-like, ACVBP (doxorubicin, cyclophosphamide, vindesine, bleomycin, and prednisone)-like or CHVmP-BV (cyclophosphamide, hydroxorubicin, Vm-26, prednisone, vincristine and bleomycin) treatment in Belgium between 1995 and 2000. In our sample, the proportion who received each of the three regimens was 78.4, 16.4, and 5.2%, respectively. Of those prescribed CHOP-like regimens, 15% received <80% average relative dose intensity (ARDI). In 210 patients treated with CHOP-21 (77% of the CHOP-like group), median survival was 7.08 years in those who received >90% of the ARDI, significantly longer than in those who received < or = 90% of the ARDI (p = 0.002). Dose reductions and/or delays, mainly due to hematological toxicities, resulted in a reduction in treatment intensity. These data indicate that patient outcome is improved when the intensity of chemotherapy treatment is optimal.

Monocytes are activated in patients with myelodysplastic syndromes and can contribute to bone marrow failure through CD40-CD40L interactions with T helper cells.

Immune mechanisms have been shown to contribute to the process of myelodysplastic syndromes (MDS)-related bone marrow (BM) failure. The aim of this study was to evaluate the possible contribution of activated monocytes through CD40-CD40L(CD154) interactions with activated T helper cells. We demonstrated in 77 predominantly lower risk MDS patients that the CD40 receptor was expressed significantly higher on monocytes and that CD40L was expressed significantly higher on T helper cells in peripheral blood (PB) and BM. Increased levels of CD40 and CD40L were detected in the same patients. In addition, stimulation of the CD40 receptor on purified PB monocytes led to a significantly higher tumor necrosis factor alpha production in patients. Co-culture of BM mononuclear cells of 21 patients in the presence of a blocking CD40 monoclonal antibody (ch5D12) led to a significant increase in the number of colony-forming units. A correlation was seen between increased CD40 expression on monocytes with patients' age below 60 years and with the cytogenetic abnormality trisomy 8. These results demonstrate that CD40 expression on monocytes may identify a subgroup of MDS patients in whom immune-mediated hematopoietic failure is part of the disease process. As such, the CD40-CD40L-based activation of monocytes might be a target to counteract MDS-related BM failure.

A new disease categorization of low-grade myelodysplastic syndromes based on the expression of cytopenia and dysplasia in one versus more than one lineage improves on the WHO classification.

Multilineage dysplasia was advanced by the World Health Organization to increase prognostic accuracy in myelodysplastic syndromes (MDS) classification. We performed a structured cytomorphological examination of bone marrow (BM) in 221 low-grade MDS patients, this in conjunction with strict guidelines for cytopenias. A dysplasia scoring system was developed utilizing dysplastic changes, which were associated with worse outcome on univariate and multivariate analysis corrected for the International Prognostic Scoring System (IPSS). Dysplasia >or=10% in one BM lineage and one cytopenia constituted the low-risk category UCUD or Unilineage Cytopenia and Unilineage Dysplasia. The high-risk category comprised patients with cytopenia in >or=2 lineages and dysplasia in >or=2 BM lineages, namely MCMD or Multilineage Cytopenia and Multilineage Dysplasia. Intermediate-risk patients had one cytopenia and multilineage dysplasia, or cytopenia in >or=2 lineages and unilineage BM dysplasia, designated UCMD/MCUD or Unilineage Cytopenia and Multilineage Dysplasia/Multilineage Cytopenia and Unilineage Dysplasia. This system utilizing cytopenia-dysplasia scoring at diagnosis enabled comprehensive categorization of low-grade MDS cases that predicted for overall as well as leukemia-free survival. Cytopenia-dysplasia categorization added additional prognostic values to the lower risk IPSS categories. This suggests that a standardized dysplasia scoring system, used in conjunction with cytopenia, could improve diagnostic and prognostic sub-categorization of MDS patients.

High-vs low-dose cytarabine combined with interferon alfa in patients with first chronic phase chronic myeloid leukemia. A prospective randomized phase III study.

A prospective randomized phase III study was performed to evaluate whether intensified cytarabine would induce a higher response rate and longer event-free interval as compared to low-dose cytarabine in chronic myeloid leukemia (CML). One hundred and eighteen patients with CML in early chronic phase entered the study. Twenty-eight out of 32 patients assigned to group A received two cycles of a combination of intensified cytarabine and idarubicin followed by interferon alfa (IFN-alpha) maintenance, 28 patients in group B received standard treatment by a combination of low-dose cytarabine and IFN-alpha. Forty-nine patients with a human leukocyte antigen-identical sibling donor proceeded to allogeneic stem cell transplantation (allo-SCT) and nine patients were excluded from the analysis. Hematological response was observed in 97% of the patients in group A vs 86% of the patients in group B during the first year of treatment. In group A, 16 patients (50%) achieved a major cytogenetic response, which compared to seven patients (25%) with a major cytogenetic response in group B. With a median follow-up of 58 months (range 34-76), event-free survival was not significantly different between arms A and B. The estimated 5-year survival rate was 56% in the intensified arm and 77% in the low-dose arm (P = 0.05). Recipients of allo-SCT showed a 5-year estimated survival rate of 55%. Although intensified cytarabine induced a higher initial percentage of major and complete cytogenetic responses, responses were not sustained by IFN-alpha maintenance therapy.

A patient with Hodgkin's lymphoma, antiphospholipid syndrome and severe mitral insufficiency.

The association between Hodgkin's lymphoma, antiphospholipid syndrome and severe mitral insufficiency is a very rare event. We report on a 25-year-old female patient suffering from Hodgkin's lymphoma and presenting with thromboembolic events and severe mitral insufficiency. The possible link between these symptoms being antiphospholipid antibodies, is discussed briefly.

Relationship between classic Hodgkin lymphoma and overlapping large cell lymphoma investigated by comparative expressed sequence hybridization expression profiling.

There is a diagnostic grey zone between classic Hodgkin lymphoma (cHL) and some non-Hodgkin lymphoma (NHL), including primary mediastinal B cell lymphoma, diffuse large B cell lymphoma, and anaplastic large cell lymphoma. They all have some morphological and/or phenotypic features in common. To investigate this, we undertook an expression profiling study of these lymphomas using comparative expressed sequence hybridization. This technique detects chromosomal regions that are differentially expressed between a test and a reference tissue in a manner similar to comparative genomic hybridization, and is particularly suitable when the number of informative biopsies is limited. Using this approach, we identified a unique expression profile for all lymphoma types investigated. Unsupervised hierarchical cluster analysis of the acquired data showed that cHL separates from all investigated NHLs, including ALCL-like HL. Moreover, anaplastic lymphoma kinase (ALK)-negative ALCL clustered in a separate branch together with ALCL-like HL. Thus, analysing the neoplastic cells concurrently with their microenvironment, ALK-negative ALCL and ALCL-like HL seem to be related to each other, while cHL constitutes a separate lymphoma entity.

An epigenetic approach to the treatment of advanced MDS; the experience with the DNA demethylating agent 5-aza-2'-deoxycytidine (decitabine) in 177 patients.

During the last 10 years, three European phase II studies were performed to investigate the treatment of elderly patients with myelodysplastic syndrome (MDS) with low-dose 5-aza-2'-deoxycytidine (decitabine, DAC). All these European trial data were reviewed on the basis of the International Prognostic Scoring System (IPSS) risk criteria and the response criteria as recently published by an international working group. To investigate the results in a larger cohort of patients and to determine risk factors, all data were pooled with some observations from the PCH 95-06 US phase II study. The response rate in the 177 patients evaluated (median age 70 years) was 49%. The median response duration was 36 weeks, and the median survival was 15 months. Analysis of the data according to sex, age, French-American-British classification, percentage of blasts in the bone marrow, IPSS risk group, lactate dehydrogenase and cytogenetics did not reveal any factor predictive of response. Overall, 69% of patients benefited, including those with stable disease during therapy. Response duration was significantly shorter with increasing risk (according to the IPSS classification). Haemoglobin level and neutrophil count showed an inverse correlation to the IPSS classification. Univariate analysis showed a significantly inferior survival for elderly patients (>75 years of age) and for those with high levels of serum lactate dehydrogenase (LDH) (more than two times the normal values). Patients with high-risk cytogenetic abnormalities according to the IPSS risk criteria showed better overall survival than those with intermediate-risk abnormalities. When analysed according to the IPSS risk classification, high-risk patients had worse survival prospects following decitabine therapy than those with intermediate risk; however, compared to the originally reported IPPS outcomes for high-risk patients, they probably showed better survival. During the treatment period, 18% of the patients progressed towards acute leukaemia. Decitabine showed a rather low toxicity profile in this elderly patient group. In conclusion, low-dose decitabine is an active drug for the treatment of MDS patients, even for those older than 75 years with bad prognostic characteristics.

Circulating myeloid and lymphoid precursor dendritic cells are clonally involved in myelodysplastic syndromes.

Circulating myeloid and lymphoid precursor dendritic cell (pDC) counts were determined in peripheral blood from 22 patients with myelodysplastic syndromes (MDS) by a single-platform flow cytometric protocol. The absolute count of myeloid and lymphoid pDC, as well as their relative number (as proportion of mononuclear cells or total leukocytes) was significantly lower in MDS (n=22) than in healthy controls (n=41). In 11 patients with chromosomal aberrations, purified pDC were examined by interphase fluorescence in situ hybridization. This revealed clonal involvement of myeloid as well as lymphoid pDC in all of them. These data therefore strongly suggest that myeloid and lymphoid pDC share a common precursor. Whether reduced peripheral blood counts of pDC contribute to the immunological abnormalities observed in MDS remains to be investigated.