Minimal/Measurable Residual Disease Monitoring in NPM1-Mutated Acute Myeloid Leukemia: A Clinical Viewpoint and Perspectives

Acute myeloid leukemia (AML) with NPM1 gene mutations is currently recognized as a distinct entity, due to its unique biological and clinical features. We summarize here the results of published studies investigating the clinical application of minimal/measurable residual disease (MRD) in patients with NPM1-mutated AML, receiving either intensive chemotherapy or hematopoietic stem cell transplantation. Several clinical trials have so far demonstrated a significant independent prognostic impact of molecular MRD monitoring in NPM1-mutated AML and, accordingly, the Consensus Document from the European Leukemia Net MRD Working Party has recently recommended that NPM1-mutated AML patients have MRD assessment at informative clinical timepoints during treatment and follow-up. However, several controversies remain, mainly with regard to the most clinically significant timepoints and the MRD thresholds to be considered, but also with respect to the optimal source to be analyzed, namely bone marrow or peripheral blood samples, and the correlation of MRD with other known prognostic indicators. Moreover, we discuss potential advantages, as well as drawbacks, of newer molecular technologies such as digital droplet PCR and next-generation sequencing in comparison to conventional RQ-PCR to quantify NPM1-mutated MRD. In conclusion, further prospective clinical trials are warranted to standardize MRD monitoring strategies and to optimize MRD-guided therapeutic interventions in NPM1-mutated AML patients

Targeting neoplastic B cells and harnessing microenvironment: the “double face” of ibrutinib and idelalisib

Relapsed or refractory diffuse large B-cell lymphoma (DLBCL) not suitable for high dose chemotherapy with autologous stem cell transplantation (ASCT) has a dismal prognosis and no standard therapy. We designed an Italian multicenter retrospective study aimed at evaluating the safety and efficacy of rituximab plus bendamustine (R–B) as salvage treatment in patients not eligible for ASCT because of age and/or comorbidity or in patients with post-ASCT recurrence. Fifty-five patients with a median age of 76 years were included. The overall response rate was 50%, including 28% complete remission and 22% partial remission. The median overall survival (OS) was 10.8 months. The median progression free survival (PFS) was 8.8 months. Eleven patients are still alive and in complete remission at last follow-up (12–71 months). Toxicity was moderate, mainly grades 1 and 2. R–B showed promising efficacy results with an acceptable toxicity profile and should be further investigated, possibly in combination with novel drugs

Efficacy of imatinib mesylate as maintenance therapy in adults with acute lymphoblastic leukemia in first complete remission

Seven Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) patients in first complete remission received maintenance therapy with imatinib alone. Two-year progression-free survival was 75%. Quantitative polymerase-chain-reaction (qPCR) monitoring of BCR-ABL showed that: (i) persisting molecular complete response (CR) was associated with long-lasting CR; (ii) molecular relapse did not invariably mean hematologic relapse; (iii) only the wide and rapid increment of BCR-ABL values was predictive of leukemia relapse

Photoactivity of nanostructured porous Nb2O5 : effect of Pt, Ta, Cu, and Ti impregnation

In the present work, we report the obtaining of nanostructured porous Nb2O5 by anodizing process, with Pt, Ta, Cu, or Ti impregnation, and by magnetron sputtering process. The techniques of scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to evaluate the morphology, and the composition and crystalline structure of nanoporous Nb2O5. The photocatalytic activity was evaluated by electrochemical photocurrent tests under UV light illumination. Nanostructured porous Nb2O5 with Pt, Ta, Cu, and Ti impregnation presented bandgap reduction and 10 times higher photocurrent density in the presence of UV light when compared to the not impregnated nanoporous Nb2O5

Different Resorptive Patterns of Two Avulsed and Replanted Upper Central Incisors Based on Scanning Electron Microscopy and Stereomicroscopic Analysis: A Case Report

Dental trauma resulting in permanent tooth avulsion commonly affects the young population. The prognosis of replantation after avulsion depends on the natural history of inflammatory and replacement resorption. Several risk factors for type and onset of external resorption have been defined. This case study describes different resorptive patterns observed in two upper central incisors belonging to a single individual, avulsed in the same moment, and replanted after thirty-six hours of dry storage. The roots were analyzed by scanning electron microscopy and stereomicroscope imaging, to obtain an in-depth analysis of the resorptive pattern. The aim of this report is to: (i) underline the high variability in the incidence of root resorption after replantation across and within types of teeth and resorption; and (ii) underline the possible concurrence of different factors affecting the onset and type of resorptive pattern. In conclusion, an unpredictable pattern of resorption may account for the poor prognosis when teeth are replanted outside the current recommendations

Missense mutations in the PML/RAR alpha ligand binding domain in ATRA-resistant As2O3 sensitive relapsed acute promyelocytic leukemia

Background and Objectives. Acute promyelocytic leukemia is characterized by the chromosomal translocation t(15;17) which yields the fusion product PML/RAR alpha. Art-trans retinoic acid probably induces differentiation of atypical promyelocytes and clinical remission in APL patients by binding to the ligand binding domain (LBD) of the RAR alpha portion of the PML-RAR alpha chimeric protein. Structural alterations of the LED of the PML/RAR alpha have been revealed in ATRA-resistant APL cell lines and in a few APL patients with acquired clinical resistance to ATRA therapy. Two APL relapsed patients with clinical resistance to ATRA therapy were evaluated for the presence of nucleotide mutations in the LED of PML/RAR alpha gene and then treated with arsenic trioxide (As2O3). Design and Methods. DNA fragments from the LED of the PML/RAR alpha: chimeric transcript were obtained by reverse-transcribed polymerase chain reaction. Direct sequencing was performed by an unambiguous bidirectional automatic analysis. Samples representative of APL onset and relapse were analyzed from both patients. Results. In both patients, at the ATRA-resistant relapse, a missense point mutation in the LED of the PML/RAR alpha gene was found. The mutations, absent at APL onset, led to an Arg272Gln and to an Arg276Trp amino acid substitution, according to the sequence of the RAR alpha protein. Both patients had complete clinical and hematologic remission after treatment with As2O3. Interpretation and Conclusions. LED missense mutations appear to be a significant mechanism of acquired ATRA-resistance in vivo, closely related to clinical APL relapse. The two cases reported here provide the first in vivo evidence of Apt, relapsed patients, who have become ATRA-resistant for molecular reasons, being sensitive to arsenic trioxide

Dried Volumetric Microsampling Approaches for the Therapeutic Drug Monitoring of Psychiatric Patients Undergoing Clozapine Treatment

Clozapine is one of the most widely used second-generation antipsychotic drugs (SGAs) for the treatment of schizophrenia. Despite advantages over first-generation drugs, clozapine still shows significant side effects and interindividual variations in efficacy. In order to ensure frequent therapeutic drug monitoring (TDM) and improve the compliance of psychiatric patients undergoing clozapine treatment, two novel dried microsampling approaches based on whole blood and plasma volumetric absorptive microsampling (b-VAMS and p-VAMS) and microfluidic generated-dried blood spot technology (mfDBS) were developed and coupled to HPLC with electrochemical detection (ED). The proposed miniaturized strategies by means of VAMS and microfluidic channel-based devices provide several advantages in terms of collection, storage, and handling compared to classical blood and plasma processing. Satisfactory validation results were obtained for all microsampling platforms, with mean extraction yields >85.1%, precision as relative standard deviation (RSD) < 5.1%, and stability < 4.5% analyte loss after 30 days for p-VAMS; mean extraction yields > 83.4%, precision RSD < 5.4%, and stability < 4.6% analyte loss after 30 days for b-VAMS, and mean extraction yields > 74.0%, precision RSD < 5.6%, and stability < 4.9% analyte loss after 30 days for mfDBS. The original microsampling methodologies have been successfully applied to the blood and plasma collected from five psychiatric patients for the monitoring of the levels of clozapine and its main metabolites, providing robust and reliable quali-quantitative results. Comparisons between results of the two dried microsampling technologies with those obtained by classic fluid plasma analysis were in good agreement and have demonstrated that the proposed miniaturized approaches could be suitable for TDM purposes

Sensitive detection of circulating breast cancer cells by reverse-transcriptase polymerase chain reaction of maspin gene

Background: Maspin, a recently identified protein related to the family of serpins, is believed to play a role in human breast cancer. In an effort to improve the present methods of detection, we have developed a reverse-transcriptase polymerase chain reaction (RT-PCR) assay for maspin transcript to identify small numbers of mammary carcinoma cells in the peripheral blood and bone marrow of patients with breast cancer. Patients and methods: Five non-neoplastic mammary tissue samples, 13 breast cancer specimens as well as 17 peripheral blood and 4 bone marrow samples from normal subjects were screened for the presence of maspin mRNA by RT-PCR. The same assay was applied to peripheral blood or bone marrow samples obtained from 29 patients with stages I to IV breast cancer. Results: By RT-PCR it was possible to amplify maspin mRNA in all of the primary and metastatic breast cancer specimens, but in none of the normal hemopoietic samples from healthy donors. Thus, detection of maspin transcript in the peripheral blood or marrow of a patient known to have breast cancer is indicative of the presence of mammary carcinoma cells. In reconstitution experiments, maspin RT-PCR reliably detected 10 mammary carcinoma cells in 1 million normal peripheral-blood mononuclear cells (PBMCs). None of the 9 patients with stages I, II, or III breast cancer had maspin transcript in peripheral blood. Of note, 3 of 9 patients with stage TV breast cancer receiving systemic therapy at the time of sample collection, but only I of 11 patients with stage IV not receiving therapy, had detectable maspin transcript in peripheral blood. Moreover, 3 marrow specimens from stage TV patients tested positive by this assay. Conclusions: This pilot study suggests that maspin RT-PCR assay is a sensitive, specific and sufficiently rapid method for detection of small numbers of circulating cells and marrow micrometastases in breast cancer patients. The possibility of applying this assay in the detection of tumor cell contamination of both marrow and stem-cell apheresis harvests of breast cancer patients merits further investigation

Lenalidomide interferes with tumor-promoting properties of nurse-like cells in chronic lymphocytic leukemia

Lenalidomide is an immunomodulatory agent clinically active in chronic lymphocytic leukemia patients. The specific mechanism of action is still undefined, but includes modulation of the microenvironment. In chronic lymphocytic leukemia patients, nurse-like cells differentiate from CD14(+) mononuclear cells and protect chronic lymphocytic leukemia cells from apoptosis. Nurse-like cells resemble M2 macrophages with potent immunosuppressive functions. Here, we examined the effect of lenalidomide on the monocyte/macrophage population in chronic lymphocytic leukemia patients. We found that lenalidomide induces high actin polymerization on CD14(+) monocytes through activation of small GTPases, RhoA, Rac1 and Rap1 that correlated with increased adhesion and impaired monocyte migration in response to CCL2, CCL3 and CXCL12. We observed that lenalidomide increases the number of nurse-like cells that lost the ability to nurture chronic lymphocytic leukemia cells, acquired properties of phagocytosis and promoted T-cell proliferation. Gene expression signature, induced by lenalidomide in nurse-like cells, indicated a reduction of pivotal pro-survival signals for chronic lymphocytic leukemia, such as CCL2, IGF1, CXCL12, HGF1, and supported a modulation towards M1 phenotype with high IL2 and low IL10, IL8 and CD163. Our data provide new insights into the mechanism of action of lenalidomide that mediates a pro-inflammatory switch of nurse-like cells affecting the protective microenvironment generated by chronic lymphocytic leukemia into tissues