Abelardo Bárez

Risk of progression in smouldering myeloma and monoclonal gammopathies of unknown significance: comparative analysis of the evolution of monoclonal component and multiparameter flow cytometry of bone marrow plasma cells

The present study explored the impact of two novel criteria; having >95% abnormal plasma cells by flow cytometry at diagnosis and the evolving subtype of the disease, as predictors of progression in 61 smouldering multiple myeloma (SMM) and 311 monoclonal gammopathy of unknown significance (MGUS) patients. Although both criteria were of prognostic value, the risk of progression was better identified by immunophenotyping [Hazard Ratio (HR) 6·2 and 17·2 for SMM and MGUS, respectively] than evolving subtype, which had independent prognostic value only in MGUS (HR 3·6). Immunophenotyping discriminated the different risk of progression within the evolving and non‐evolving subgroups of SMM (P = 0·01) and MGUS (P < 0·001).

Methylation is an inactivating mechanism of the p16 gene in multiple myeloma associated with high plasma cell proliferation and short survival.

Summary. In order to gain further insights into the role of the p16 gene in cell cycle regulation and the prognostic implications of its inactivation, we investigated the methylation status of the p16 gene in 98 untreated patients using a polymerase chain reaction assay based on the inability of some restriction enzymes to digest methylated sequences. Forty‐one patients showed a p16 methylated gene (42%). The percentage of S‐phase plasma cells (PC) in these patients was almost three times higher than in those with an unmethylated p16 gene (4·16% ± 3·37%vs 1·5% ± 1·41%, P < 0·001). The presence of p16 methylation also correlated with both elevated β2‐microglobulin serum levels and high C‐reactive protein values. Patients with a p16 methylated gene had shorter overall and progression‐free survival than those patients without p16 methylation. However, this feature did not retain independent prognostic influence on multivariate analysis, probably due to its association with the S‐phase PC, which had more potent statistical significance in the Cox model. These findings showed methylation of the p16 gene was a frequent event inMM patients at diagnosis, and was associated with an increased proliferative rate of plasma cells and a poor prognosis, indicating an important role for p16 gene in the cell cycle regulation of multiple myeloma tumour cells, and thus in the clinical outcome of the disease.

Molecular stratification model for prognosis in cytogenetically normal acute myeloid leukemia

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.

PD-L1/PD-1 presence in the tumor microenvironment and activity of PD-1 blockade in multiple myeloma

PD-L1/PD-1 presence in the tumor microenvironment and activity of PD-1 blockade in multiple myeloma

Next Generation Flow for highly sensitive and standardized detection of minimal residual disease in multiple myeloma

Flow cytometry has become a highly valuable method to monitor minimal residual disease (MRD) and evaluate the depth of complete response (CR) in bone marrow (BM) of multiple myeloma (MM) after therapy. However, current flow-MRD has lower sensitivity than molecular methods and lacks standardization. Here we report on a novel next generation flow (NGF) approach for highly sensitive and standardized MRD detection in MM. An optimized 2-tube 8-color antibody panel was constructed in five cycles of design-evaluation-redesign. In addition, a bulk-lysis procedure was established for acquisition of ⩾107 cells/sample, and novel software tools were constructed for automatic plasma cell gating. Multicenter evaluation of 110 follow-up BM from MM patients in very good partial response (VGPR) or CR showed a higher sensitivity for NGF-MRD vs conventional 8-color flow-MRD -MRD-positive rate of 47 vs 34% (P=0.003)-. Thus, 25% of patients classified as MRD-negative by conventional 8-color flow were MRD-positive by NGF, translating into a significantly longer progression-free survival for MRD-negative vs MRD-positive CR patients by NGF (75% progression-free survival not reached vs 7 months; P=0.02). This study establishes EuroFlow-based NGF as a highly sensitive, fully standardized approach for MRD detection in MM which overcomes the major limitations of conventional flow-MRD methods and is ready for implementation in routine diagnostics.

Real-world clinical experience with long-term miglustat maintenance therapy in type 1 Gaucher disease: the ZAGAL project

There are few published data from real-world clinical experience with miglustat, an oral inhibitor of glucosylceramide synthase, in type 1 Gaucher disease. This study suggests that miglustat is an effective therapy for the long-term maintenance of patients with type 1 Gaucher disease previously stabilized with enzyme replacement therapy. There are few published data from real-world clinical experience with miglustat (Zavesca®), an oral inhibitor of glucosylceramide synthase, in type 1 Gaucher disease. We report data from a prospective, open-label investigational study that evaluated substrate reduction therapy with miglustat 100 mg t.i.d. as a maintenance therapy in patients with Type 1 Gaucher disease who had been switched from previous enzyme replacement therapy. Long-term data on changes in organ size, blood counts, disease severity bio-markers, bone marrow infiltration, overall clinical status and safety/tolerability were analyzed from 28 patients with Type 1 Gaucher disease who were attending routine clinic visits. Assessments were performed at six, 12, 24, 36 and 48 months of therapy. Disease severity biomarkers improved up to 48 months after initiation of miglustat, while other disease parameters remained stable. Miglustat showed an acceptable profile of safety and tolerability throughout treatment. In conclusion, miglustat is an effective therapy for the long-term maintenance of patients with Type 1 Gaucher disease previously stabilized with enzyme replacement therapy.

Proliferative activity of plasma cells is the most relevant prognostic factor in elderly multiple myeloma patients.

Although multiple myeloma (MM) is predominantly a disease of the elderly, few studies have focused on the identification of prognostic factors in this group of patients. Four hundred twenty five MM patients >65 years were uniformly treated with chemotherapy (MP or VCMP/VBAD). Multivariate analysis identified 4 factors with independent unfavorable prognostic influence: high percentage of S‐phase bone marrow plasma cells (>2.5%); elevated β2 microglobulin (B2M) (>4 mg/L); age >80 years old; and LDH serum levels (above normal limit). The S‐phase value was the most powerful independent prognostic factor to discriminate subgroups of patients with different prognosis. Thus, 3 main risk categories could be identified according to S‐phase values: ≤1%, 1–3% and >3%, with median survivals of 34, 22 and 12 months, respectively (p < 0.0001). Our study also proved the value for elderly patients of the recently developed International Score System (ISS) based on B2M and albumin. Furthermore, the number of S‐phase cells helped to subdivide the ISS III Group identifying a subset of patients with very poor prognosis defined by an additional high S‐phase, who displayed a median survival of only 8 months. These results demonstrate that elderly patients can be accurately classified according to prognosis, which may be particularly valuable when comparing the efficacy of new treatment strategies. Moreover, our results underline the high prognostic value of proliferative activity of PC, a parameter that should be considered in routine laboratory investigations of MM.

The clinical utility and prognostic value of multiparameter flow cytometry immunophenotyping in light-chain amyloidosis

The clinical value of multiparameter flow cytometry (MFC) immunophenotyping in primary or light chain amyloidosis (AL) remains unknown. We studied 44 consecutive bone marrow samples from newly diagnosed patients with amyloidosis; 35 patients with AL and 9 with other forms of amyloidosis. Monoclonal plasma cells (PCs) were identifiable by MFC immunophenotyping in 34 of 35 (97%) patients with AL, whereas it was absent from all but 1 of the 9 (11%) patients with other forms of amyloidosis. Quantification of bone marrow plasma cells (BMPCs) by MFC immunophenotyping was a significant prognostic factor for overall survival (OS) (≤ 1% vs > 1% BMPC cutoff; 2-year OS rates of 90% vs 44%, P = .02). Moreover, detecting persistent normal PCs at diagnosis identifies a subgroup of patients with AL with prolonged OS (> 5% vs ≤ 5% normal PC within all BMPC cutoff, 2-year rates of 88% vs 37%, P = .01). MFC immunophenotyping could be clinically useful for the demonstration of PC clonality in AL and for the prognostication of patients with AL.

Multiparameter flow cytometry for the identification of the Waldenstrom's clone in IgM-MGUS and Waldenstrom's Macroglobulinemia: new criteria for differential diagnosis and risk stratification

Although multiparameter flow cytometry (MFC) has demonstrated clinical relevance in monoclonal gammopathy of undetermined significance (MGUS)/myeloma, immunophenotypic studies on the full spectrum of Waldenström’s Macroglobulinemia (WM) remain scanty. Herein, a comprehensive MFC analysis on bone marrow samples from 244 newly diagnosed patients with an immunoglobulin M (IgM) monoclonal protein was performed, including 67 IgM-MGUS, 77 smoldering and 100 symptomatic WM. Our results show a progressive increase on the number and light-chain-isotype-positive B-cells from IgM-MGUS to smoldering and symptomatic WM (P<.001), with only 1% of IgM-MGUS patients showing >10% B cells or 100% light-chain-isotype-positive B-cells (P<.001). Complete light-chain restriction of the B-cell compartment was an independent prognostic factor for time-to progression in smoldering WM (median 26 months; HR: 19.8, P=0.001) and overall survival in symptomatic WM (median 44 months; HR: 2.6, P=0.004). The progressive accumulation of light-chain-isotype-positive B-cells accompanied the emergence of a characteristic Waldenstrom’s phenotype (CD22+dim/CD25+/CD27+/IgM+) that differed from other B-NHL by negative expression of CD5, CD10, CD11c or CD103. In contrast to myeloma, light-chain-isotype-positive plasma cells in IgM monoclonal gammopathies show otherwise normal antigenic expression. Our results highlight the potential value of MFC immunophenotyping for the characterization of the Waldenström’s clone, as well as for the differential diagnosis, risk of progression and survival in WM.

High FOXO3a expression is associated with a poorer prognosis in AML with normal cytogenetics.

The PI3/AKT pathway is up-regulated in acute myeloid leukemia (AML), but its prognostic relevance in cytogenetically normal AML (CN-AML) is unclear. We evaluated RNA levels of AKT and two downstream substrates (FOXO3a-p27) in 110 de novo CN-AML, included in the Spanish PETHEMA therapeutic protocols. Patients with high FOXO3a gene expression displayed shorter OS (p=0.015) and RFS (p=0.048) than low FOXO3a expressers. Features selected in the multivariate analysis as having an independent prognostic value for a shorter survival were WBC>50x10(9)/L, age >65 years and high FOXO3a expression. We concluded that FOXO3a assessment could contribute to improve the molecular-based risk stratification in CN-AML.