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Abstract: A reciprocal t(3;8) BCL6::MYC fusion is common in large B-cell lymphoma (LBCL) with MYC and BCL6 disruption. These pseudo-double-hit cases are not adverse, whereas t(3;8)-MYC/BCL6 lymphoma has an inferior prognosis relative to other MYC-rearranged LBCL., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Patients with familial platelet disorder with a predisposition to myeloid malignancy (FPDMM) harbor germline monoallelic mutations in a key hematopoietic transcription factor, RUNX-1. Previous studies of FPDMM have focused on megakaryocyte (Mk) differentiation and platelet production and signaling. However, the effects of RUNX-1 haploinsufficiency on hematopoietic progenitor cells (HPCs) and subsequent megakaryopoiesis remains incomplete. We studied induced pluripotent stem cell (iPSC)-derived HPCs (iHPCs) and Mks (iMks) from both patient-derived lines and a wild-type (WT) line modified to be RUNX-1 haploinsufficient (RUNX-1+/-), each compared with their isogenic WT control. All RUNX-1+/- lines showed decreased iMk yield and depletion of an Mk-biased iHPC subpopulation. To investigate global and local gene expression changes underlying this iHPC shift, single-cell RNA sequencing was performed on sorted FPDMM and control iHPCs. We defined several cell subpopulations in the Mk-biased iHPCs. Analyses of gene sets upregulated in FPDMM iHPCs indicated enrichment for response to stress, regulation of signal transduction, and immune signaling-related gene sets. Immunoblot analyses in FPDMM iMks were consistent with these findings, but also identified augmented baseline c-Jun N-terminal kinase (JNK) phosphorylation, known to be activated by transforming growth factor-β1 (TGF-β1) and cellular stressors. These findings were confirmed in adult human CD34+-derived stem and progenitor cells (HSPCs) transduced with lentiviral RUNX1 short hairpin RNA to mimic RUNX-1+/-. In both iHPCs and CD34+-derived HSPCs, targeted inhibitors of JNK and TGF-β1 pathways corrected the megakaryopoietic defect. We propose that such intervention may correct the thrombocytopenia in patients with FPDMM.

Risk of developing myelodysplastic syndrome (MDS) is significantly increased in both multiple myeloma (MM) and monoclonal gammopathy of undetermined significance, suggesting that it is therapy independent. However, the incidence and sequelae of dysplastic hematopoiesis at diagnosis are unknown. Here, we used multidimensional flow cytometry (MFC) to prospectively screen for the presence of MDS-associated phenotypic alterations (MDS-PA) in the bone marrow of 285 patients with MM enrolled in the PETHEMA/GEM2012MENOS65 trial (#NCT01916252). We investigated the clinical significance of monocytic MDS-PA in a larger series of 1252 patients enrolled in 4 PETHEMA/GEM protocols. At diagnosis, 33 (11.6%) of 285 cases displayed MDS-PA. Bulk and single-cell-targeted sequencing of MDS recurrently mutated genes in CD34+ progenitors (and dysplastic lineages) from 67 patients revealed clonal hematopoiesis in 13 (50%) of 26 cases with MDS-PA vs 9 (22%) of 41 without MDS-PA; TET2 and NRAS were the most frequently mutated genes. Dynamics of MDS-PA at diagnosis and after autologous transplant were evaluated in 86 of 285 patients and showed that in most cases (69 of 86 [80%]), MDS-PA either persisted or remained absent in patients with or without MDS-PA at diagnosis, respectively. Noteworthy, MDS-associated mutations infrequently emerged after high-dose therapy. Based on MFC profiling, patients with MDS-PA have altered hematopoiesis and T regulatory cell distribution in the tumor microenvironment. Importantly, the presence of monocytic MDS-PA at diagnosis anticipated greater risk of hematologic toxicity and was independently associated with inferior progression-free survival (hazard ratio, 1.5; P = .02) and overall survival (hazard ratio, 1.7; P = .01). This study reveals the biological and clinical significance of dysplastic hematopoiesis in newly diagnosed MM, which can be screened with moderate sensitivity using cost-effective MFC., (© 2020 by The American Society of Hematology.)

Competing Interests: Conflict-of-interest disclosure: The authors declare no competing financial interests.

A hallmark of the diffuse large B-cell lymphoma (DLBCL) of the activated B-cell (ABC) type, a molecular subtype characterized by adverse outcome, is constitutive activation of the transcription factor nuclear factor-κB (NF-κB), which controls expression of genes promoting cellular survival and proliferation. Much less, however, is known about the role of the transcription factor activator protein-1 (AP-1) in ABC DLBCL. Here, we show that AP-1, like NF-κB, was controlled by constitutive activation of the B-cell receptor signaling component caspase recruitment domain-containing membrane-associated guanylate kinase 1 (CARMA1) and/or the Toll-like receptor signaling component myeloid differentiation primary response gene 88 (MyD88) in ABC DLBCL cell lines. In contrast to germinal center (GC) B-cell (GCB) DLBCL, ABC DLBCL cell lines expressed high levels of the AP-1 family members c-Jun, JunB, and JunD, which formed heterodimeric complexes with the AP-1 family members activating transcription factor (ATF) 2, ATF3, and ATF7. Inhibition of these complexes by a dominant-negative approach led to impaired growth of a majority of ABC DLBCL cell lines. Individual silencing of c-Jun, ATF2, or ATF3 decreased cellular survival and revealed c-Jun/ATF2-dependent control of ATF3 expression. As a consequence, ATF3 expression was much higher in ABC vs GCB DLBCL cell lines. Samples derived from DLBCL patients showed a clear trend toward high and nuclear ATF3 expression in nodal DLBCL of the non-GC or ABC subtype. These findings identify the activation of AP-1 complexes of the Jun/ATF-type as an important element controlling the growth of ABC DLBCL., (© 2016 by The American Society of Hematology.)

Angioimmunoblastic T-cell lymphoma (AITL) is the second most common peripheral T-cell lymphoma with unusual clinical and pathologic features and a poor prognosis despite intensive chemotherapy. Recent studies have suggested AITL derives from follicular helper T (T(FH)) cells, but the causative molecular pathways remain largely unknown. Here we show that approximately 50% of mice heterozygous for the "san" allele of Roquin develop tumors accompanied by hypergammaglobulinemia by 6 months of age. Affected lymph nodes displayed the histologic features diagnostic of AITL, except for the presence of expanded FDC networks. Accumulation of T(FH) cells preceded tumor development, and clonal rearrangements in the TCR-β genes were present in most tumors. Furthermore, T(FH) cells exhibited increased clonality compared with non-T(FH) cells from the same lymph nodes, even in the absence of tumors. Genetic manipulations that prevent T(FH) development, such as deletion of ICOS, CD28, and SAP, partially or completely abrogated tumor development, confirming a T(FH)-derived origin. Roquin(san/+) mice emerge as a useful model to investigate the molecular pathogenesis of AITL and for preclinical testing of therapies aimed at targeting dysregulated T(FH) cells or their consequences.

Few studies have examined the outcome of large numbers of patients with the microgranular variant (M3V) of acute promyelocytic leukemia (APL) in the all-trans retinoic acid era. Here, the outcome of 155 patients treated with all-trans retinoic acid-based therapy on 3 clinical trials, North American Intergroup protocol I0129 and Programa para el Estudio de la Terapéutica en Hemopatía Maligna protocols LPA96 and LPA99, are reported. The complete remission rate for all 155 patients was 82%, compared with 89% for 748 patients with classical M3 disease. The incidence of the APL differentiation syndrome was 26%, compared with 25% for classical M3 patients, and the early death rate was 13.6% compared with 8.4% for patients with classical M3 morphology. With a median follow-up time among survivors of 7.6 years (range 3.6-14.5), the 5-year overall survival, disease-free survival, and cumulative incidence of relapse for patients with M3V were 70%, 73%, and 24%, respectively. With a median follow-up time among survivors of 7.6 years (range 0.6-14.3), the 5-year overall survival, disease-free survival, and cumulative incidence of relapse among patients with classical M3 morphology were 80% (P = .006 compared with M3V), 81% (P = .07), and 15% (P = .005), respectively. When outcomes were adjusted for the white blood cell count or the relapse risk score, none of these outcomes were significantly different between patients with M3V and classical M3 APL.

We have evaluated 9 new molecular markers (ERG, EVI1, MLL-PTD, MN1, PRAME, RHAMM, and WT1 gene-expression levels plus FLT3 and NPM1 mutations) in 121 de novo cytogenetically normal acute myeloblastic leukemias. In the multivariate analysis, high ERG or EVI1 and low PRAME expressions were associated with a shorter relapse-free survival (RFS) and overall survival (OS). A 0 to 3 score was given by assigning a value of 0 to favorable parameters (low ERG, low EVI1, and high PRAME) and 1 to adverse parameters. This model distinguished 4 subsets of patients with different OS (2-year OS of 79%, 65%, 46%, and 27%; P = .001) and RFS (2-year RFS of 92%, 65%, 49%, and 43%; P = .005). Furthermore, this score identified patients with different OS (P = .001) and RFS (P = .013), even within the FLT3/NPM1 intermediate-risk/high-risk subgroups. Here we propose a new molecular score for cytogenetically normal acute myeloblastic leukemias, which could improve patient risk-stratification.

The antithrombin A384S mutation has a relatively high frequency in the British population but has not been identified in other populations. This variant has been associated with cases of thrombotic disease, but its clinical relevance in venous thrombosis remained unclear. We have conducted a secondary analysis of the prevalence of the mutation in a large case-control study, including 1018 consecutive Spanish patients with venous thromboembolism. In addition, we evaluated its functional consequences in 20 carriers (4 homozygous). This mutation, even in the homozygous state, did not affect anti-Xa activity or antigen levels, and it only slightly impaired anti-IIa activity. Thus, routine clinical methods cannot detect this anomaly, and, accordingly, this alteration could have been underestimated. We identified this mutation in 0.2% of Spanish controls. Among patients, this variant represented the first cause of antithrombin anomalies. Indeed, 1.7% patients carried the A384S mutation, but 0.6% had any other antithrombin deficiency. The mutated allele was associated with an increased risk of venous thrombosis with an adjusted OR of 9.75 (95% CI, 2.2-42.5). This is the first study supporting that antithrombin A384S mutation is a prevalent genetic risk factor for venous thrombosis and is the most frequent cause of antithrombin deficiency in white populations.

Leukemic B-chronic lymphoproliferative disorders (B-CLPDs) are generally believed to derive from a monoclonal B cell; biclonality has only occasionally been reported. In this study, we have explored the incidence of B-CLPD cases with 2 or more B-cell clones and established both the phenotypic differences between the coexisting clones and the clinicobiologic features of these patients. In total, 53 B-CLPD cases with 2 or more B-cell clones were studied. Presence of 2 or more B-cell clones was suspected by immunophenotype and confirmed by molecular/genetic techniques in leukemic samples (n = 42) and purified B-cell subpopulations (n = 10). Overall, 4.8% of 477 consecutive B-CLPDs had 2 or more B-cell clones, their incidence being especially higher among hairy cell leukemia (3 of 13), large cell lymphoma (2 of 10), and atypical chronic lymphocytic leukemia (CLL) (4 of 29). In most cases the 2 B-cell subsets displayed either different surface immunoglobulin (sIg) light chain (n = 37 of 53) or different levels of the same sIg (n = 9 of 53), usually associated with other phenotypic differences. Compared with monoclonal cases, B-CLL patients with 2 or more clones had lower white blood cell (WBC) and lymphocyte counts, more frequently displayed splenomegaly, and required early treatment. Among these, the cases in which a CLL clone coexisted with a non-CLL clone were older and more often displayed B symptoms, a monoclonal component, and diffuse infiltration of bone marrow and required early treatment more frequently than cases with monoclonal CLL or 2 CLL clones.

Induction of transplantation tolerance to alloantigens without general immunosuppression remains an enduring challenge. Injecting a donor-specific transfusion (DST) of spleen cells together with blocking alphaCD154 antibody prior to graft transplantation is an effective way to induce long-lived graft acceptance. Using a novel T-cell receptor (TCR) transgenic (Tg) model of CD4+ T-cell-mediated rejection, this study sheds new insights into the cellular basis for enhanced graft survival induced by DST and alphaCD154. The study shows that DST and alphaCD154 induce an early, robust, abortive expansion of the Tg T cells that results in profound anergy. This is contrasted with the more delayed, regional, productive response elicited by an allogeneic graft. Studies show that the induction of tolerance to the allograft induced by DST is mediated by indirect presentation by host antigen-presenting cells. Based on these observations, we conclude that DST and alphaCD154 preemptively tolerize the alloreactive T-cell compartment to prohibit subsequent responses to the immunogenic allograft.

Preliminary independent reports of the Italian GIMEMA and the Spanish PETHEMA trials for newly diagnosed acute promyelocytic leukemia (APL) indicated a similarly high antileukemic efficacy in terms of complete remission and disease-free survival rates. To better investigate these studies and the prognostic factors influencing relapse risk, this study analyzed the updated results of 217 patients with PML/RAR alpha-positive APL enrolled in GIMEMA (n = 108) and PETHEMA (n = 109). All patients received identical induction (AIDA schedule) and maintenance. For consolidation, GIMEMA patients received 3 courses including idarubicin/cytarabine, mitoxantrone/etoposide, and idarubicin/cytarabine/thioguanine, whereas PETHEMA patients received the same drugs and dose schedule of idarubicin and mitoxantrone with the omission of nonintercalating agents. Depending on whether molecular relapses were classified as censored or uncensored events, the 3-year Kaplan-Meier estimates of relapse-free survival (RFS) for the combined series were 90 +/- 2% and 86 +/- 2%, respectively. Minor differences observed between the 2 patient cohorts were negligible. Multivariate regression analysis of RFS showed that initial leukocyte (WBC) and platelet counts were the only variables with independent prognostic value. The resulting predictive model for RFS demonstrated its capability of segregating patients into low-risk (WBC count 40 x 10(9)/L), intermediate-risk (WBC count 10 x 10(9)/L) groups, with distinctive RFS curves (P <.0001). The conclusions are that omission of nonanthracycline drugs from the AIDA regimen is not associated with reduced antileukemic efficacy and a simple predictive model may be used for risk-adapted therapy in this disease. (Blood. 2000;96:1247-1253)

We studied lineage-specific chimerism and minimal residual disease (MRD) in sequential posttransplant samples from 55 patients who underwent unmanipulated (n = 44) or partially T-cell-depleted (n = 11) allogeneic bone marrow transplantation (BMT) for chronic myeloid leukemia (CML). Chimerism was assessed by polymerase chain reaction (VNTR [variable number of tandem repeats]-PCR) analysis in highly purified CD19+, CD3+, CD15+, and CD56+ cell fractions, whereas MRD was investigated in whole blood by reverse transcriptase-PCR (RT-PCR) of both p210(BCR-ABL) and p190(BCR-ABL) hybrid transcripts. Of 55 patients, 14 (including 6 T-cell-depleted patients) had cytogenetic relapse at 5-80 months and progressed to hematologic relapse, while 41 patients remained in prolonged cytogenetic remission 12-107 months post-BMT. Before leukemia recurrence, patients in the relapse group showed a consistent evolution pattern sequentially featured by persistent p210(BCR-ABL) positivity, increasing mixed chimerism (MC) in myeloid cells, p190(BCR-ABL) positivity, and, finally, cytogenetic relapse. Myeloid MC preceded cytogenetic relapse by 2-12 months, whereas p190(BCR/ABL) was detected 1-6 months prior to cytogenetic relapse in 11 patients and concomitant with cytogenetic relapse in 3 patients. In the remission group, all patients invariably tested negative for p190(BCR-ABL); 10 patients tested positive for p210(BCR-ABL) at variable time-points but showed persistent full donor chimerism (DC), whereas 31 patients tested p210(BCR-ABL) negative and displayed full DC or transient MC due to the persistence of recipient T cells. Two patients in the relapse group were successfully reinduced into molecular remission with donor lymphocyte infusion. Sequential molecular analysis after such treatment showed the inverse pattern to that observed prior to relapse, ie, progressive disappearance of p190(BCR-ABL) transcripts, conversion of myeloid chimerism to donor type, and, finally, p210(BCR-ABL) negativity. We conclude that lineage-specific chimerism and p190(BCR-ABL) messenger RNA (mRNA) analyses contribute a better characterization of CML evolution after BMT and enable early identification of patients at the highest risk of relapse. (Blood. 2000;95:2659-2665)