Distinct peripheral T-cell and NK-cell profiles in HGBL-MYC/BCL2 vs patients with DLBCL NOS.

ABSTRACT: Patients with high-grade B-cell lymphoma with MYC and BCL2 rearrangements (HGBL-MYC/BCL2) respond poorly to immunochemotherapy compared with patients with diffuse large B-cell lymphoma not otherwise specified (DLBCL NOS) without a MYC rearrangement. This suggests a negative impact of lymphoma-intrinsic MYC on the immune system. To investigate this, we compared circulating T cells and natural killer (NK) cells of patients with HGBL-MYC/BCL2 (n = 66), patients with DLBCL NOS (n = 53), and age-matched healthy donors (HDs; n = 16) by flow cytometry and performed proliferation, cytokine production, and cytotoxicity assays. Compared with HDs, both lymphoma subtypes displayed similar frequencies of CD8+ T cells but decreased CD4+ T cells. Regulatory T-cell (Treg) frequencies were reduced only in patients with DLBCL NOS. Activated (HLA-DR+/CD38+) T cells, PD-1+CD4+ T cells, and PD-1+Tregs were increased in both lymphoma subtypes, but PD-1+CD8+ T cells were increased only in HGBL-MYC/BCL2. Patients with DLBCL NOS, but not patients with HGBL-MYC/BCL2, exhibited higher frequencies of senescent T cells than HDs. Functional assays showed no overt differences between both lymphoma groups and HDs. Deeper analyses revealed that PD-1+ T cells of patients with HGBL-MYC/BCL2 were exhausted with impaired cytokine production and degranulation. Patients with DLBCL NOS, but not patients with HGBL-MYC/BCL2, exhibited higher frequencies of NK cells expressing inhibiting receptor NKG2A. Both lymphoma subtypes exhibited lower TIM-3+- and DNAM-1+-expressing NK cells. Although NK cells of patients with HGBL-MYC/BCL2 showed less degranulation, they were not defective in cytotoxicity. In conclusion, our results demonstrate an increased exhaustion in circulating T cells of patients with HGBL-MYC/BCL2. Nonetheless, the overall intact peripheral T-cell and NK-cell functions in these patients emphasize the importance of investigating potential immune evasion in the microenvironment of MYC-rearranged lymphomas.

Treatment strategies for polycythemia vera: Observations in a Dutch "real-world" cohort study.

OBJECTIVES: Assessment of "real-world" treatment strategies and outcome in Dutch polycythemia vera (PV) patients. METHODS: Retrospective chart review in 150 patients with PV (WHO 2008 diagnostic criteria) from 10 major non-academic hospitals in the Netherlands. RESULTS: Patients (median age 64 years, 49% male) frequently had cardiovascular risk factors (56%) and prior vascular events (31%). About 70% of patients were high-risk, based on ELN criteria. However, the majority of patients were treated with phlebotomies alone (55%). Cytoreduction with hydroxyurea (HU) was received by 44% as part of their initial therapy, with or without phlebotomies. The time to achieve the 45% hematocrit target was shortest in patients treated with phlebotomies with or without HU (125 ± 99 and 197 ± 249 days, respectively) compared to patients treated with only HU (232 ± 216 days). Leukocyte and platelet levels were lower in HU-treated patients, and ELN response targets were more often reached. During the median follow-up period of 4.1 years, 14 patients (9%) suffered a thrombotic vascular event. CONCLUSIONS: In Dutch clinical practice, there is major clinical variation in treatment strategies for PV. Phlebotomizing patients shorten the time to achieve hematocrit control, while HU better controls platelet and leukocyte levels. The thrombotic vascular event rate remains clinically significant.

Evaluation of a panel of expert pathologists: review of the diagnosis and histological classification of Hodgkin and non-Hodgkin lymphomas in a population-based cancer registry.

Abstract Correct histological classification of malignant lymphomas is important but has always been a difficult challenge. Since 2001 the World Health Organization (WHO) classification has been used, which should make it easier to define distinct disease entities. The purpose of this study was to evaluate the usefulness of a panel of expert hematopathologists in reviewing the diagnosis of malignant lymphomas and to examine whether the discordance between primary and panel diagnoses has declined throughout the years. All patients with a primary malignant lymphoma diagnosed between 2000-2001 and 2005-2006 were identified through the population based cancer registry. All diagnoses were reviewed by a panel of three expert pathologists. In 2000-2001, 344 patients were included, and in 2005-2006, 370 patients. The overall discordance rate decreased from 14% in 2000-2001 to 9% in 2005-2006 (p = 0.06). We were able to identify lymphoma subgroups with the highest discordance rates and lowest discordance rates (mantle cell lymphoma and classical Hodgkin lymphoma), which remained unchanged throughout the years. Based on these results we would propose to review all cases of malignant lymphoma with the exception of mantle cell lymphoma and classical Hodgkin lymphoma, when the initial pathologist has no doubt about the diagnosis.

Immunogenicity of dendritic cells pulsed with MAGE3, Survivin and B-cell maturation antigen mRNA for vaccination of multiple myeloma patients.

The introduction of autologous stem cell transplantation (SCT) and novel drugs has improved overall survival in multiple myeloma (MM) patients. However, minimal residual disease (MRD) remains and most patients eventually relapse. Myeloma plasma cells express tumor-associated antigens (TAA), which are interesting targets for immunotherapy. In this phase 1 study, we investigated the safety and immunological effects of TAA-mRNA-loaded dendritic cell (DC) vaccination for treatment for MRD in MM after SCT. Mature monocyte-derived DCs were pulsed with keyhole limpet hemocyanin (KLH) and electroporated with MAGE3, Survivin or B-cell maturation antigen (BCMA) mRNA. Twelve patients were vaccinated three times with intravenous (5-22 × 10(6) DCs) and intradermal vaccines (4-11 × 10(6) DCs), at biweekly intervals. Immunological responses were monitored in blood and delayed-type hypersensitivity (DTH) biopsies. All patients developed strong anti-KLH T-cell responses, but not KLH antibodies. In 2 patients, vaccine-specific T cells were detected in DTH biopsies. In one patient, we found MAGE3-specific CD4(+) and CD8(+) T cells, and CD3(+) T cells reactive against BCMA and Survivin. In the other patient, we detected low numbers of MAGE3 and BCMA-reactive CD8(+) T cells. Vaccination was well tolerated with limited toxicity. These findings illustrate that TAA-mRNA-electroporated mature DCs are capable of inducing TAA-T-cell responses in MM patients after SCT.

Detection of the JAK2V617F mutation in patients with slightly elevated platelets or hemoglobin without a secondary cause.

Recently, an activating somatic mutation of Janus kinase 2 (JAK2V617F) was identified in the myeloproliferative disorders (MPDs). In this study, we investigated the occurrence of JAK2V617F in patients with slightly elevated platelets or hemoglobin without a secondary cause, who did not meet the criteria of polycythemia vera or essential thrombocythemia. Six out of 18 patients (33%) were positive for the JAK2 mutation, and five of these six patients had a history of thrombosis. These findings suggest that apart from thrombocytosis/erythrocytosis, other mechanisms exist that cause thrombosis, and more patients with a latent form of MPD are likely to exist. Future studies will have to elucidate how to treat these patients.