Noemi Puig

Prognostic value of deep sequencing method for minimal residual disease detection in multiple myeloma

We assessed the prognostic value of minimal residual disease (MRD) detection in multiple myeloma (MM) patients using a sequencing-based platform in bone marrow samples from 133 MM patients in at least very good partial response (VGPR) after front-line therapy. Deep sequencing was carried out in patients in whom a high-frequency myeloma clone was identified and MRD was assessed using the IGH-VDJH, IGH-DJH, and IGK assays. The results were contrasted with those of multiparametric flow cytometry (MFC) and allele-specific oligonucleotide polymerase chain reaction (ASO-PCR). The applicability of deep sequencing was 91%. Concordance between sequencing and MFC and ASO-PCR was 83% and 85%, respectively. Patients who were MRD(-) by sequencing had a significantly longer time to tumor progression (TTP) (median 80 vs 31 months; P < .0001) and overall survival (median not reached vs 81 months; P = .02), compared with patients who were MRD(+). When stratifying patients by different levels of MRD, the respective TTP medians were: MRD ≥10(-3) 27 months, MRD 10(-3) to 10(-5) 48 months, and MRD <10(-5) 80 months (P = .003 to .0001). Ninety-two percent of VGPR patients were MRD(+). In complete response patients, the TTP remained significantly longer for MRD(-) compared with MRD(+) patients (131 vs 35 months; P = .0009).

Critical evaluation of ASO RQ-PCR for minimal residual disease evaluation in multiple myeloma. A comparative analysis with flow cytometry

We have analyzed the applicability, sensitivity and prognostic value of allele-specific oligonucleotide real-time quantitative PCR (ASO RQ-PCR) as a method for minimal residual disease (MRD) assessment in patients with multiple myeloma (MM), comparing the results with those of multiparameter flow cytometry (MFC). A total of 170 patients enrolled in three consecutive Spanish trials achieving at least partial response after treatment were included. Lack of clonality detection (n=31), unsuccessful sequencing (n=17) and suboptimal ASO performance (n=51) limited the applicability of PCR to 42% of cases. MRD was finally investigated in 103 patients (including 32 previously studied) with persistent disease identified by PCR and MFC in 54% and 46% of cases, respectively. A significant correlation in MRD quantitation by both the techniques was noted (r=0.881, P<0.001), being reflective of treatment intensity. Patients with <10−4 residual tumor cells showed longer progression-free survival (PFS) compared with the rest (not reached (NR) vs 31 months, P=0.002), with similar results observed with MFC. Among complete responders (n=62), PCR discriminated two risk groups with different PFS (49 vs 26 months, P=0.001) and overall survival (NR vs 60 months, P=0.008). Thus, although less applicable than MFC, ASO RQ-PCR is a powerful technique to assess treatment efficacy and risk stratification in MM.

Autoimmune hemolytic anemia following allogeneic hematopoietic stem cell transplantation in adult patients

Autoimmune hemolytic anemia (AIHA) after allogeneic hematopoietic stem cell transplantation (HSCT) is still not well characterized. The aim of this study was to analyze the incidence and risk factors for the development of AIHA, as well as its prognosis and response to treatment in a series of patients undergoing allogeneic HSCT at a single institution. Between 1996 and 2004, 272 adult patients with a variety of malignant hematopoietic disorders underwent allogeneic HSCT. Direct antiglobulin testing was performed in routine pretransfusion compatibility testing or after clinical suspicion of AIHA. Twelve patients developed AIHA after HSCT at a median time of 147 days (range, 41–170). The 3-year cumulative incidence of AIHA was 4.44%. Eight cold antibodies and four warm antibodies were detected. Multivariate analysis shows that HSCT from unrelated donors (P=0.02) and the development of chronic extensive graft-versus-host disease (GVHD) (P=0.0004) were the only independent factors associated with AIHA. Two patients are still alive. AIHA was never the primary cause of death but added morbidity in patients with other concomitant complications. Patients undergoing HSCT from unrelated donors and those who develop chronic extensive GVHD are especially predisposed for this complication.

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.

Immunophenotype of normal vs. myeloma plasma cells: Toward antibody panel specifications for MRD detection in multiple myeloma

In recent years, several studies on large series of multiple myeloma (MM) patients have demonstrated the clinical utility of flow cytometry monitoring of minimal residual disease (flow‐MRD) in bone marrow (BM), for improved assessment of response to therapy and prognostication. However, disturbing levels of variability exist regarding the specific protocols and antibody panels used in individual laboratories. Overall, consensus exists about the utility of combined assessment of CD38 and CD138 for the identification of BM plasma cells (PC); in contrast, more heterogeneous lists of markers are used to further distinguish between normal/reactive PCs and myeloma PCs in the MRD settings. Among the later markers, CD19, CD45, CD27, and CD81, together with CD56, CD117, CD200, and CD307, have emerged as particularly informative; however, no single marker provides enough specificity for clear discrimination between clonal PCs and normal PCs. Accordingly, multivariate analyses of single PCs from large series of normal/reactive vs. myeloma BM samples have shown that combined assessment of CD138 and CD38, together with CD45, CD19, CD56, CD27, CD81, and CD117 would be ideally suited for MRD monitoring in virtually every MM patient. However, the specific antibody clones, fluorochrome conjugates and sources of the individual markers determines its optimal (vs. suboptimal or poor) performance in an eight‐color staining. Assessment of clonality, via additional cytoplasmic immunoglobulin (CyIg) κ vs. CyIgλ evaluation, may contribute to further establish the normal/reactive vs. clonal nature of small suspicious PC populations at high sensitivity levels, provided that enough cells are evaluated.

Morbidity and transplant-related mortality of CBV and BEAM preparative regimens for patients with lymphoid malignancies undergoing autologous stem-cell transplantation

CBV and BEAM are the two most frequently used regimens for patients with lymphoma undergoing autologous hematopoietic stem-cell transplantation (ASCT). This study compared their morbidity and transplant-related mortality (TRM) in 113 patients with non-Hodgkins lymphoma (69) and Hodgkins disease (44) undergoing ASCT between 1990 – 2004. CBV (cyclophosphamide, 6000 mg m−2; VP-16, 750 mg m−2; and high-dose BCNU, 800 mg m−2) was administered to 75 patients and 38 received BEAM (BCNU, 300 mg m−2; VP-16, 800 mg m−2; cytarabine, 800 mg m−2; melphalan, 140 mg m−2). Patients in the BEAM group had a significantly higher median age (p = 0.002) and were more heavily treated before ASCT (p = 0.003). More patients showed active disease at transplant in the BEAM group (p = 0.04). Sinusoidal obstruction syndrome (SOS) was more frequent in the CBV group (11% vs 0%, p = 0.048). There were 20 (18%) transplant-related deaths, 18 in the CBV and two in the BEAM group. Infectious complications (12 patients, seven with pneumonia) and SOS (four) were the most frequent causes of death. The cumulative incidences of TRM were 25% in the CBV and 7% in the BEAM group (p = 0.02). CBV thus produced a higher incidence of SOS and TRM than BEAM in this series.

Minimal residual disease monitoring and immune profiling in multiple myeloma in elderly patients

The value of minimal residual disease (MRD) in multiple myeloma (MM) has been more frequently investigated in transplant-eligible patients than in elderly patients. Because an optimal balance between treatment efficacy and toxicity is of utmost importance in patients with elderly MM, sensitive MRD monitoring might be particularly valuable in this patient population. Here, we used second-generation 8-color multiparameter-flow cytometry (MFC) to monitor MRD in 162 transplant-ineligible MM patients enrolled in the PETHEMA/GEM2010MAS65 study. The transition from first- to second-generation MFC resulted in increased sensitivity and allowed us to identify 3 patient groups according to MRD levels: MRD negative (<10(-5); n = 54, 34%), MRD positive (between <10(-4) and ≥10(-5); n = 20, 12%), and MRD positive (≥10(-4); n = 88, 54%). MRD status was an independent prognostic factor for time to progression (TTP) (hazard ratio [HR], 2.7; P = .007) and overall survival (OS) (HR, 3.1; P = .04), with significant benefit for MRD-negative patients (median TTP not reached, 70% OS at 3 years), and similar poorer outcomes for cases with MRD levels between <10(-4) and ≥10(-5) vs ≥10(-4) (both with a median TTP of 15 months; 63% and 55% OS at 3 years, respectively). Furthermore, MRD negativity significantly improved TTP of patients >75 years (HR, 4.8; P < .001), as well as those with high-risk cytogenetics (HR, 12.6; P = .01). Using second-generation MFC, immune profiling concomitant to MRD monitoring also contributed to identify patients with poor, intermediate, and favorable outcomes (25%, 61%, and 100% OS at 3 years, respectively; P = .01), the later patients being characterized by an increased compartment of mature B cells. Our results show that similarly to transplant candidates, MRD monitoring is one of the most relevant prognostic factors in elderly MM patients, irrespectively of age or cytogenetic risk. This trial was registered at www.clinicaltrials.gov as #NCT01237249.

Molecular characterization of immunoglobulin gene rearrangements in diffuse large B-cell lymphoma: antigen-driven origin and IGHV4-34 as a particular subgroup of the non-GCB subtype.

The pathogenesis of diffuse large B-cell lymphoma (DLBCL) remains partially unknown. The analysis of the B-cell receptor of the malignant cells could contribute to a better understanding of the DLBCL biology. We studied the molecular features of the immunoglobulin heavy chain (IGH) rearrangements in 165 patients diagnosed with DLBCL not otherwise specified. Clonal IGH rearrangements were amplified according to the BIOMED-2 protocol and PCR products were sequenced directly. We also analyzed the criteria for stereotyped patterns in all complete IGHV-IGHD-IGHJ (V-D-J) sequences. Complete V-D-J rearrangements were identified in 130 of 165 patients. Most cases (89%) were highly mutated, but 12 sequences were truly unmutated or minimally mutated. Three genes, IGHV4-34, IGHV3-23, and IGHV4-39, accounted for one third of the whole cohort, including an overrepresentation of IGHV4-34 (15.5% overall). Interestingly, all IGHV4-34 rearrangements and all unmutated sequences belonged to the nongerminal center B-cell-like (non-GCB) subtype. Overall, we found three cases following the current criteria for stereotyped heavy chain VH CDR3 sequences, two of them belonging to subsets previously described in CLL. IGHV gene repertoire is remarkably biased, implying an antigen-driven origin in DLBCL. The particular features in the sequence of the immunoglobulins suggest the existence of particular subgroups within the non-GCB subtype.

BAALC is an important predictor of refractoriness to chemotherapy and poor survival in intermediate-risk acute myeloid leukemia (AML)

We have analyzed brain and acute leukemia, cytoplasmic (BAALC) gene expression and other genetic markers (ERG, EVI1, MN1, PRAME, WT1, FLT3, and NPM1 mutations) in 127 intermediate-risk acute myeloid leukemia (AML) patients: 98 cytogenetically normal and 29 with intermediate-risk cytogenetic alterations. High versus low BAALC expressers showed a higher refractoriness to induction treatment (31% vs 10%; p = .005), lower complete remission rate after salvage therapy (82% vs 97%; p = .010), and lower 3-year overall (23% vs 58%, p < .001) and relapse-free survival (26% vs 52%, p = .006). Similar results were found when cytogenetic subgroups were analyzed separately. Multivariate models confirmed the unfavorable prognosis of this marker. In conclusion, BAALC is a relevant prognostic marker in intermediate-risk AML.