Pre-transplant minimal residual disease assessment and transplant-related factors predict the outcome of acute myeloid leukemia patients undergoing allogeneic stem cell transplantation.

We studied pretransplant minimal residual disease (MRD) in 224 patients (median age 44 years; range 17-65) with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplant (HSCT) in complete remission. MRD was evaluated on marrow samples using multicolor flow cytometry and assessment of WT1 gene expression. Both methods showed a strong prognostic value and their combination allowed the identification of three groups of patients with different risk of relapse. In multivariate analysis, combined MRD was the only predictor of cumulative incidence of relapse, regardless of donor type, conditioning regimen, first or second CR at HSCT, HSCT year, and ELN risk group. Multivariate regression model showed that only negative combined MRD status (P < .001) and myeloablative conditioning (P = .004) were independently associated with better OS. Among MRD-positive patients, a reduced incidence of relapse was observed in patients receiving haplo transplant (P < .05) and in patients who showed grade II-IV aGVHD (P < .03). In patients with negative combined MRD, the intensity of conditioning regimen did not affect the overall favorable outcome. We suggest that pretransplant MRD evaluation combined with transplant-related factors can identify AML patients at higher risk for relapse and might help in defining the overall transplant strategy.

Prognostic relevance of a blastic plasmacytoid dendritic cell neoplasm-like immunophenotype in cytogenetically normal acute myeloid leukemia patients.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a poor prognosis myeloid malignancy characterized by an atypical phenotype (CD123+, CD56+, and CD4+). We reported that BPDCN-like phenotype (CD123+ and either CD56+ or CD4+ or both) confers poor prognosis to acute myeloblastic leukemia (AML) patients with mutated NPM1. Here, we evaluated the incidence and the prognostic relevance of BPDCN-like phenotype in cytogenetically normal AML (CN-AML) patients. From 2006 to 2016, 83 young (age <60 yrs), consecutive, CN-AML patients underwent intensive treatment. Fifteen patients (18%) showed a BPDCN-like phenotype with no difference between NPM1-mutated (mut) and NPM1-wt patients. It did not significantly affect survival neither in the whole cohort, nor in NPM1-wt patients. However, as reported, it conferred a dismal prognosis in NPM1-mut AML (p < 0.001), irrespectively of the mutational status for FLT3-ITD. In conclusion we show that BPDCN-like phenotype displays a negative prognostic relevance only in NPM1-mutated AML.

Health technology assessment-based approach to flow cytometric immunophenotyping of acute leukemias: a literature classification.

OBJECTIVE: Acute leukemia (AL) is a broad, heterogeneous group of malignant diseases. The diagnostic workup of AL is based on several clinical and laboratory findings, including flow cytometric immunophenotyping. However, the role of this assay in the diagnosis of AL has not been systematically investigated. The aim of this study was to determine the accuracy and utility of flow cytometric immunophenotyping in the identification, characterization, and staging of AL. METHODS: We performed a systematic selection and classification of the literature since 1980, focused on flow cytometric immunophenotyping of AL. We applied a 6-variables model to cover both the technical capabilities and the clinical value of flow cytometric immunophenotyping in the diagnosis of AL. RESULTS: Using 3 key words (acute leukemia, immunophenotyping, flow cytometry), we screened the literature from January 1985 to April 2015 in PubMed and Embase databases and found 1010 articles. A total of 363 were selected and submitted to the expert panel, which selected a final data set of 248 articles to be analyzed. Of these, 160 were focused on clinical and biological issues, 55 were technical articles, and 31 were reviews. These 248 articles were then analyzed according to the 6-variables model and definitively classified. CONCLUSIONS: We assessed the literature on flow cytometric immunophenotyping of AL over 3 decades as the first step toward an evidence-based analysis of the impact of this technology on the clinical management of patients with AL.

A simple cytofluorimetric score may optimize testing for biallelic CEBPA mutations in patients with acute myeloid leukemia.

Acute myeloid leukemia with biallelic mutation of CEBPA (CEBPA-dm AML) is a distinct good prognosis entity recognized by WHO 2016 classification. However, testing for CEBPA mutation is challenging, due to the intrinsic characteristics of the mutation itself. Indeed, molecular analysis cannot be performed with NGS technique and requires Sanger sequencing. The association of recurrent mutations or translocations with specific immunophenotypic patterns has been already reported in other AML subtypes. The aim of this study was the development of a specific cytofluorimetric score (CEBPA-dm score), in order to distinguish patients who are unlikely to harbor the mutation. To this end, the correlation of CEBPA-dm score with the presence of the mutation was analyzed in 50 consecutive AML patients with normal karyotype and without NPM1 mutation (that is mutually exclusive with CEBPA mutation). One point each was assigned for expression of HLA DR, CD7, CD13, CD15, CD33, CD34 and one point for lack of expression of CD14. OS was not influenced by sex, age and CEBPA-dm score. Multivariate OS analysis showed that CEBPA-dm (p < 0.02) and FLT3-ITD (p < 0.01) were the strongest independent predictors of OS. With a high negative predictive value (100%), CEBPA-dm score < 6 was able to identify patients who are unlikely to have the mutation. Therefore, the application of this simple score might optimize the use of expensive and time-consuming diagnostic and prognostic assessment in the baseline work up of AML patients.

High feasibility and antileukemic efficacy of fludarabine, cytarabine, and idarubicin (FLAI) induction followed by risk-oriented consolidation: A critical review of a 10-year, single-center experience in younger, non M3 AML patients.

About 105 consecutive acute myeloid leukemia (AML) patients treated with the same induction-consolidation program between 2004 and 2013 were retrospectively analyzed. Median age was 47 years. The first induction course included fludarabine (Flu) and high-dose cytarabine (Ara-C) plus idarubicin (Ida), with or without gemtuzumab-ozogamicin (GO) 3 mg/m(2) (FLAI-5). Patients achieving complete remission (CR) received a second course without fludarabine but with higher dose of idarubicin. Patients not achieving CR received an intensified second course. Patients not scheduled for early allogeneic bone marrow transplantation (HSCT) where planned to receive at least two courses of consolidation therapy with Ara-C. Our double induction strategy significantly differs from described fludarabine-containing regimens, as patients achieving CR receive a second course without fludarabine, to avoid excess toxicity, and Ara-C consolidation is administrated at the reduced cumulative dose of 8 g/m(2) per cycle. Toxicity is a major concern in fludarabine containing induction, including the recent Medical Research Council AML15 fludarabine, cytarabine, idaraubicin and G-CSF (FLAG-Ida) arm, and, despite higher anti-leukemic efficacy, only a minority of patients is able to complete the full planned program. In this article, we show that our therapeutic program is generally well tolerated, as most patients were able to receive subsequent therapy at full dose and in a timely manner, with a 30-day mortality of 4.8%. The omission of fludarabine in the second course did not reduce efficacy, as a CR rate of 83% was achieved and 3-year disease-free survival and overall survival (OS) were 49.6% and 50.9%, respectively. Our experience shows that FLAI-5/Ara-C + Ida double induction followed by risk-oriented consolidation therapy can result in good overall outcome with acceptable toxicity. Am. J. Hematol. 91:755-762, 2016. © 2016 Wiley Periodicals, Inc.

Aminobisphosphonates prevent the inhibitory effects exerted by lymph node stromal cells on anti-tumor Vδ 2 T lymphocytes in non-Hodgkin lymphomas.

In this study, we analyzed the influence of mesenchymal stromal cells derived from lymph nodes of non-Hodgkin's lymphomas, on effector functions and differentiation of Vdelta (δ)2 T lymphocytes. We show that: i) lymph-node mesenchymal stromal cells of non-Hodgkin's lymphoma inhibit NKG2D-mediated lymphoid cell killing, but not rituximab-induced antibody-dependent cell-mediated cytotoxicity, exerted by Vδ2 T lymphocytes; ii) pre-treatment of mesenchymal stromal cells with the aminobisphosphonates pamidronate or zoledronate can rescue lymphoma cell killing via NKG2D; iii) this is due to inhibition of transforming growth factor-ß and increase in interleukin-15 production by mesenchymal stromal cells; iv) aminobisphosphonate-treated mesenchymal stromal cells drive Vδ2 T-lymphocyte differentiation into effector memory T cells, expressing the Thelper1 cytokines tumor necrosis factor-α and interferon-γ. In non-Hodgkin's lymphoma lymph nodes, Vδ2 T cells were mostly naïve; upon co-culture with autologous lymph-node mesenchymal stromal cells exposed to zoledronate, the percentage of terminal differentiated effector memory Vδ2 T lymphocytes increased. In all non-Hodgkin's lymphomas, low or undetectable transcription of Thelper1 cytokines was found. In diffused large B-cell lymphomas and in a group of follicular lymphoma, transcription of transforming growth factor ß and interleukin-10 was enhanced compared to non-neoplastic lymph nodes. Thus, in non-Hodgkin lymphomas mesenchymal stromal cells interfere with Vδ2 T-lymphocyte cytolytic function and differentiation to Thelper1 and/or effector memory cells, depending on the prominent in situ cytokine milieu. Aminobisphosphonates, acting on lymph-node mesenchymal stromal cells, can push the balance towards Thelper1/effector memory and rescue the recognition and killing of lymphoma cells through NKG2D, sparing rituximab-induced antibody-dependent cell-mediated cytotoxicity.

Integrating post induction WT1 quantification and flow-cytometry results improves minimal residual disease stratification in acute myeloid leukemia.

Fifty uniformly treated adult AML patients were analyzed with respect to pre-treatment and post-induction risk factors. Forty-two patients achieving complete hematological remission were assessed for minimal residual disease (MRD) by WT1 gene expression; 34 by flow-cytometry (flow-MRD). Patients who were flow-MRD negative had a better 3-year disease-free (DFS; 79.5% vs. 27.3%; p=.032) compared with patients who were still positive after induction. Interestingly, DFS of flow-MRD positive patients was not related to the amount of flow-detected clone population (≥ or <1%, p=.41) but to WT1 reduction (ΔWT1, 3-year DFS; 46.2% vs. 0% if ΔWT1 was ≥ or < of 1.5 log, p=.001). In AML, combining MRD results provided by WT1 quantification and flow-cytometry improves the reliability of MRD-based prognostic stratification. Similar analyses by further larger studies should be advocated.

High ERp5/ADAM10 expression in lymph node microenvironment and impaired NKG2D ligands recognition in Hodgkin lymphomas.

Herein we describe that in classic Hodgkin lymphomas (cHL, n = 25) the lymph node (LN) stroma displayed in situ high levels of transcription and expression of the disulfide-isomerase ERp5 and of the disintegrin-metalloproteinase ADAM10, able to shed the ligands for NKG2D (NKG2D-L) from the cell membrane. These enzymes were detected both in LN mesenchymal stromal cells (MSCs) and in Reed-Sternberg (RS) cells; in addition, MIC-A and ULBP3 were present in culture supernatants of LN MSCs or RS cells. NKG2D-L-negative RS cells could not be killed by CD8(+)αßT or γδT cells; tumor cell killing was partially restored by treating RS cells with valproic acid, which enhanced NKG2D-L surface expression. Upon coculture with LN MSCs, CD8(+)αßT and γδT cells strongly reduced their cytolytic activity against NKG2D-L(+) targets; this seems to be the result of TGF-ß, present at the tumor site, produced in vitro by LN MSCs and able to down-regulate the expression of NKG2D on T lymphocytes. In addition, CD8(+)αßT and γδT cells from the lymph nodes of cHL patients, cocultured in vitro with LN MSCs, underwent TGF-ß-mediated down regulation of NKG2D. Thus, in cHL the tumor microenvironment is prone to inhibit the development of an efficient antitumor response.

Multipotent mesenchymal stromal cells from amniotic fluid: solid perspectives for clinical application.

BACKGROUND: Mesenchymal stromal cells are multipotent cells considered to be of great promise for use in regenerative medicine. However, the cell dose may be a critical factor in many clinical conditions and the yield resulting from the ex vivo expansion of mesenchymal stromal cells derived from bone marrow may be insufficient. Thus, alternative sources of mesenchymal stromal cells need to be explored. In this study, mesenchymal stromal cells were successfully isolated from second trimester amniotic fluid and analyzed for chromosomal stability to validate their safety for potential utilization as a cell therapy product. DESIGN AND METHODS: Mesenchymal stromal cells were expanded up to the sixth passage starting from amniotic fluid using different culture conditions to optimize large-scale production. RESULTS: The highest number of mesenchymal stromal cells derived from amniotic fluid was reached at a low plating density; in these conditions the expansion of mesenchymal stromal cells from amniotic fluid was significantly greater than that of adult bone marrow-derived mesenchymal stromal cells. Mesenchymal stromal cells from amniotic fluid represent a relatively homogeneous population of immature cells with immunosuppressive properties and extensive proliferative potential. Despite their high proliferative capacity in culture, we did not observe any karyotypic abnormalities or transformation potential in vitro nor any tumorigenic effect in vivo. CONCLUSIONS: Fetal mesenchymal stromal cells can be extensively expanded from amniotic fluid, showing no karyotypic abnormalities or transformation potential in vitro and no tumorigenic effect in vivo. They represent a relatively homogeneous population of immature mesenchymal stromal cells with long telomeres, immunosuppressive properties and extensive proliferative potential. Our results indicate that amniotic fluid represents a rich source of mesenchymal stromal cells suitable for banking to be used when large amounts of cells are required.

Clinical scale ex vivo expansion of cord blood-derived outgrowth endothelial progenitor cells is associated with high incidence of karyotype aberrations.

OBJECTIVE: Endothelial progenitor cells (EPCs) are involved in neovessel formation. So far, therapeutic angiogenesis is hampered by the low frequency and limited proliferative potential of these cells isolated from peripheral blood. Recently, it has been shown that cord blood-derived EPCs (CB EPCs) can be ex vivo expanded on a clinical scale. In this study, we evaluated the expansion potential of CB EPCs together with their phenotypic, functional, and chromosomal stability over time. MATERIALS AND METHODS: Flow cytometry, in vitro tube formation, and proliferation assays were performed to characterize CB EPC-derived cells. Chromosomal stability was evaluated by karyotype analysis. In vitro and in vivo tumorigenicity was evaluated by soft agar assay and injection into nonobese diabetic/severe combined immunodeficient mice, respectively. RESULTS: We showed that CB EPC-derived cells displayed phenotypic and functional features of EPCs, although a process of maturation was observed over time. Although we confirmed that CB EPCs have a greater expansion potential compared to peripheral blood EPCS, we observed a high incidence of cytogenetic alterations (71%) in the expanded endothelial cell population, even at early times of culture. In two cases, spontaneous transformation in vitro was documented, but none of the samples tested showed tumorigenic potential in vivo. Conversely, no karyotype alterations have been observed on peripheral blood EPCs-derived cells. CONCLUSIONS: We confirm that CB represents a good source for clinical ex vivo expansion of EPCs. However, because of high frequency of karyotype alterations, these cells cannot be considered free of risk in clinical application.

Buccal mucosa cells as in vivo model to evaluate gefitinib activity in patients with advanced non small cell lung cancer.

PURPOSE: To evaluate the role of pretreatment and posttreatment expression in buccal mucosa cells of signal transduction proteins activated by epidermal growth factor receptor, including phosphorylated epidermal growth factor receptor (p-EGFR), phosphorylated mitogen-activated protein kinase (p-MAPK), and phosphorylated AKT (p-AKT), in predicting gefitinib activity in advanced non-small cell lung cancer patients. Expression of the same proteins was also assessed on corresponding tissue samples for comparison. Moreover, EGFR gene mutations and copy number were analyzed. EXPERIMENTAL DESIGN: Protein expression was evaluated by standard immunocytochemistry in buccal smears, obtained by scraping immediately before and after 2 weeks of gefitinib treatment, and in the available archival tumor specimens. EGFR gene mutations were evaluated by direct sequencing and gene copy number was determined by fluorescence in situ hybridization. Data were correlated with gefitinib toxicity and objective response. RESULTS: Fifty-eight patients with pretreated advanced non-small cell lung cancer were enrolled and nine of these patients (15%) showed an objective response to gefitinib (including two complete responses). Toxicity (P = 0.025) and baseline p-AKT expression in buccal mucosa cells (P = 0.061) showed a potential predictive role. On the contrary, the probability of achieving an objective response was not affected by pretreatment expression of EGFR, p-EGFR, and p-MAPK, either in buccal mucosa or in tumor tissue. Responders showed a nonstatistically significant trend toward a more pronounced reduction in the expression of p-EGFR, p-MAPK, and p-AKT after gefitinib treatment. Among responders, five of six (83%) tumors showed EGFR gene mutation, whereas none of the tumors from patients with stable or progressive disease did (P < 0.001). CONCLUSIONS: Epithelial cells obtained from buccal mucosa may be used to assess the pharmacodynamic effect of EGFR-targeted agents, and pretreatment p-AKT expression may be a possible predictive biomarker of in vivo gefitinib activity.

CD8+ CD28- T regulatory lymphocytes inhibiting T cell proliferative and cytotoxic functions infiltrate human cancers.

Tumor growth is allowed by its ability to escape immune system surveillance. An important role in determining tumor evasion from immune control might be played by tumor-infiltrating regulatory lymphocytes. This study was aimed at characterizing phenotype and function of CD8+ CD28- T regulatory cells infiltrating human cancer. Lymphocytes infiltrating primitive tumor lesion and/or satellite lymph node from a series of 42 human cancers were phenotypically studied and functionally analyzed by suppressor assays. The unprecedented observation was made that CD8+ CD28- T regulatory lymphocytes are almost constantly present and functional in human tumors, being able to inhibit both T cell proliferation and cytotoxicity. CD4+ CD25+ T regulatory lymphocytes associate with CD8+ CD28- T regulatory cells so that the immunosuppressive activity of tumor-infiltrating regulatory T cell subsets, altogether considered, may become predominant. The infiltration of regulatory T cells seems tumor related, being present in metastatic but not in metastasis-free satellite lymph nodes; it likely depends on both in situ generation (via cytokine production) and recruitment from the periphery (via chemokine secretion). Collectively, these results have pathogenic relevance and implication for immunotherapy of cancer.

Grading of laboratories on CD4+ T-lymphocyte evaluations based on acceptable data boundaries defined by the measurement error.

BACKGROUND: We addressed the definition of limits of error of %CD4+ and CD4+ counts (AbsCD4+) typical of laboratories of excellence, as well as the grading of laboratories based on the decision to take these limits as boundaries of unacceptable data. METHODS: We studied the 99.9% confidence intervals of the means of 24 human immunodeficiency virus (HIV)+ and HIV- blood samples analyzed by 18 laboratories of the Liguria Region Quality Assessment Program (Liguria Region QALI). Regression equations of lower (L1) and upper (L2) confidence limits over the means of data cleared of unusual results were used to interpolate limits of error for mean values in the tested range. RESULTS: L1 and L2 were symmetric around the mean and a single absolute difference (Abs Res) between the limits and the mean was found. Abs Res significantly increased over mean values (P = 0.0005 for %CD4+, P < 0.0001 for AbsCD4+). Limits were compatible with errors shown with blind replicates. Unacceptable results, outside the limits, accounted for 25% and 30% of %CD4+ and for 18% and 35% AbsCD4+ in the Liguria Region QALI and in the Piemonte Region QA Program, respectively. Limits interpolated over the median showed a similar grading. A comparable fraction of unacceptable data was also found with the method used in the U.K. National External Quality Assessment Scheme (NEQAS) immune monitoring scheme. CONCLUSIONS: We propose the general use of these regression equations to determine bounds for unacceptable data in proficiency testing and to identify laboratories of excellence.