Roadmap to cure multiple myeloma

Despite significant advances in the treatment of multiple myeloma which had led to unprecedented rates of response and survival, patients still relapse, and cure remains elusive. We propose in this review a roadmap to achieve the dream of cure for multiple myeloma based on five complementary strategies. First, to increase knowledge about disease pathogenesis with a focus on the biology of circulating tumor cells, responsible for dissemination and extramedullary disease, and minimal residual disease clones who represent the reservoir of clonal evolution and disease recurrence. Second, to consider undetectable measurable residual disease (MRD), defined by high-sensitive techniques, as the new endpoint of therapy. Third, to treat disease causation instead of symptomatology through early detection and intervention. Thereby, by treating high-risk smoldering myeloma patients early, we may not only contribute to delay disease progression into active disease but also to increase the cure rates. Fourth, to use the most active scheme in standard-risk patients if the cure is in the horizon. Fifth, to investigate experimental therapies in newly diagnosed patients with high-risk MM, implementing early rescue intervention strategies with the goal of eradicating all tumor clones, and achieving minimal residual disease negativity

Utility of flow cytometry studies in the management of patients with multiple myeloma

Purpose of review: Although the input of multiparameter flow cytometry (MFC) into the clinical management of multiple myeloma (MM) patients has faced some reluctance, continuously growing evidence supports the utility of MFC in this disease. Recent findings: MFC immunophenotyping of bone marrow and peripheral blood plasma cells affords cost-effective assessment of clonality, and provides prognostic information on the risk of progression in smoldering MM, and the identification of active MM patients with dismal outcome (e.g.: high numbers of circulating tumor cells) or long-term survival despite sub-optimal responses through the characterization of MGUS-like phenotypes. Extensive data indicates that MRD monitoring can be used as biomarker to evaluate treatment efficacy and act as surrogate for survival. The time has come to address within clinical trials, the exact role of baseline risk factors and MRD monitoring for tailored therapy in MM, which implies systematic usage of highly sensitive cost-effective, readily available and standardized MRD techniques such as MFC. Summary: Next-generation MFC should be considered mandatory in the routine evaluation of MM patients both at diagnosis and after therapy, and represents an attractive technique to integrate with high-throughput DNA and RNA-seq methods to help understanding the mechanisms behind dissemination and chemoresistance of MM

Risk Factors For Bartonella Species Infection In Blood Donors From Southeast Brazil

Bacteria from the genus Bartonella are emerging blood-borne bacteria, capable of causing long-lasting infection in marine and terrestrial mammals, including humans. Bartonella are generally well adapted to their main host, causing persistent infection without clinical manifestation. However, these organisms may cause severe disease in natural or accidental hosts. In humans, Bartonella species have been detected from sick patients presented with diverse disease manifestations, including cat scratch disease, trench fever, bacillary angiomatosis, endocarditis, polyarthritis, or granulomatous inflammatory disease. However, with the advances in diagnostic methods, subclinical bloodstream infection in humans has been reported, with the potential for transmission through blood transfusion been recently investigated by our group. The objective of this study was to determine the risk factors associated with Bartonella species infection in asymptomatic blood donors presented at a major blood bank in Southeastern Brazil. Five hundred blood donors were randomly enrolled and tested for Bartonella species infection by specialized blood cultured coupled with high-sensitive PCR assays. Epidemiological questionnaires were designed to cover major potential risk factors, such as age, gender, ethnicity, contact with companion animals, livestock, or wild animals, bites from insects or animal, economical status, among other factors. Based on multivariate logistic regression, bloodstream infection with B. henselae or B. clarridgeiae was associated with cat contact (adjusted OR: 3.4, 95% CI: 1.1-9.6) or history of tick bite (adjusted OR: 3.7, 95% CI: 1.3-13.4). These risk factors should be considered during donor screening, as bacteremia by these Bartonella species may not be detected by traditional laboratory screening methods, and it may be transmitted by blood transfusion.103Faculty Grant in Global HealthFAEPEX - UNICAMP (Fundo de Apoio ao Ensino, a Pesquisa e a Extensao - UNICAMP)Office of the Vice President for Research and Biotechnology, Western University, Western University of Health Sciences, Pomona, C

CAR T-Cells in Multiple Myeloma Are Ready for Prime Time

The survival of patients with multiple myeloma (MM) has been dramatically improved in the last decade thanks to the incorporation of second-generation proteasome inhibitors (PI), immunomodulatory drugs (IMID), and, more recently, anti-CD38 monoclonal antibodies (MoAb). Nevertheless, still, a major proportion of MM patients will relapse, underscoring the need for new therapies in this disease. Moreover, survival in patients failing the current standard of care regimens (including PI, IMIDs, and anti-CD38 MoAb), which is now defined as triple-class refractory, remains dismal, and new drugs with different mechanism of action are needed. B-cell maturation antigen (BCMA)-targeted therapies and in particular chimeric antigen receptor T cell (CAR T-cell) treatment have emerged as promising platforms to overcome refractoriness to conventional drugs. In this manuscript, we review the current available data regarding CAR T-cell therapy for MM, with a special focus on target selection, clinical results, limitations, and future strategies

Bartonella Clarridgeiae Bacteremia Detected In An Asymptomatic Blood Donor.

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.53352-

Current applications of multiparameter flow cytometry in plasma cell disorders

Multiparameter flow cytometry (MFC) has become standard in the management of patients with plasma cell (PC) dyscrasias, and could be considered mandatory in specific areas of routine clinical practice. It plays a significant role during the differential diagnostic work-up because of its fast and conclusive readout of PC clonality, and simultaneously provides prognostic information in most monoclonal gammopathies. Recent advances in the treatment and outcomes of multiple myeloma led to the implementation of new response criteria, including minimal residual disease (MRD) status as one of the most relevant clinical endpoints with the potential to act as surrogate for survival. Recent technical progress led to the development of next-generation flow (NGF) cytometry that represents a validated, highly sensitive, cost-effective and widely available technique for standardized MRD evaluation, which also could be used for the detection of circulating tumor cells. Here we review current applications of MFC and NGF in most PC disorders including the less frequent solitary plasmocytoma, light-chain amyloidosis or Waldenström macroglobulinemia

An. Acad. Bras. Ciênc.

Abstract Mesenchymal stem cells present clinical potential to recover and regenerate injured tissues in diverse pathologies. The in vitro expansion and characterization of these cells contribute to elucidation of the mechanisms of senescence and strategies involving cell therapies. This study aimed to compare specific characteristics between initial and advanced passages of mesenchymal stem cells derived from adipose tissue and bone marrow. Both cell types were characterized according to immunophenotype, osteogenic differentiation, genomic instability, migration assay, doubling population time and colony forming ability. Our results demonstrated that both cell types were able to maintain an immunophenotypic profile typical of mesenchymal stem cells during increasing passages. Adipose stem cells at initial passage presented greater migration capacity compared to advanced passage cells, and advanced passage cells proliferated faster than initial passage cells. Bone marrow stem cells at early passages presented higher osteogenic potential than advanced. At advanced passages they presented higher colony forming capacity and genetic damage than those at initial passage. These results suggest that mesenchymal stem cells maintained in culture presented characteristics of senescence that should be monitored prior the use in regenerative medicine and cells derived from bone marrow at initial passage have better potential for therapeutic use in bone tissue engineering

Daratumumab in combination with urelumab to potentiate anti-myeloma activity in lymphocytedeficient mice reconstituted with human NK cells

Daratumumab is an anti-CD38 fully human IgG1 mAb approved for multiple myeloma treatment. One of the proposed mechanisms of action is the induction of antibody-dependent cellular cytotoxicity (ADCC) mediated by NK cells. NK cells acquire surface CD137 expression in the presence of solid-phase-attached daratumumab and when encountering a daratumumab-coated CD38+ tumor cell line. In this setting, addition of the agonist anti-CD137 mAb urelumab enhances NK-cell activation increasing CD25 expression and IFNɣ production. However, in vitro ADCC is not increased by the addition of urelumab both in 4h or 24h lasting experiments. To study urelumab-increased daratumumab-mediated ADCC activity in vivo, we set up a mouse model based on the intravenous administration of a luciferase-transfected multiple myeloma cell line of human origin, human NK cells and daratumumab to immuno-deficient NSG mice. In this model, intravenous administration of urelumab 24h after daratumumab delayed tumor growth and prolonged mice survival

The phylogeography of trypanosomes from South American alligatorids and African crocodilids is consistent with the geological history of South American river basins and the transoceanic dispersal of Crocodylus at the Miocene

Background: Little is known about the diversity, phylogenetic relationships, and biogeography of trypanosomes infecting non-mammalian hosts. In this study, we investigated the influence of host species and biogeography on shaping the genetic diversity, phylogenetic relationship, and distribution of trypanosomes from South American alligatorids and African crocodilids. Methods: Small Subunit rRNA (SSU rRNA) and glycosomal Glyceraldehyde Phosphate Dehydrogenase (gGAPDH) genes were employed for phylogenetic inferences. Trypanosomes from crocodilians were obtained by haemoculturing. Growth behaviour, morphology, and ultrastructural features complement the molecular description of two new species strongly supported by phylogenetic analyses. Results: The inferred phylogenies disclosed a strongly supported crocodilian-restricted clade comprising three subclades. The subclade T. grayi comprised the African Trypanosoma grayi from Crocodylus niloticus and tsetse flies. The subclade T. ralphi comprised alligatorid trypanosomes represented by Trypanosoma ralphi n. sp. From Melanosuchus niger, Caiman crocodilus and Caiman yacare from Brazilian river basins. T. grayi and T. ralphi were sister subclades. The basal subclade T. terena comprised alligatorid trypanosomes represented by Trypanosoma terena n. sp. from Ca. yacare sharing hosts and basins with the distantly genetic related T. ralphi. This subclade also included the trypanosome from Ca. crocodilus from the Orinoco basin in Venezuela and, unexpectedly, a trypanosome from the African crocodilian Osteolaemus tetraspis. Conclusion: The close relationship between South American and African trypanosomes is consistent with paleontological evidence of recent transoceanic dispersal of Crocodylus at the Miocene/Pliocene boundaries (4–5 mya), and host-switching of trypanosomes throughout the geological configuration of South American hydrographical basins shaping the evolutionary histories of the crocodilians and their trypanosomes.We are grateful to many people who kindly helped us in crocodilian capture\ud and sample collection in Brazil, Venezuela, and Guinea Bissau. We would like\ud to thank Dr. Miguel U. Trefault Rodrigues for the animal identifications. We\ud acknowledge the Brazilian Ministry of Science, Technology and Innovation\ud (MCTI) for support through the Mamirauá Institute for Sustainable\ud Development (IDSM). We thank Cristina Schwartz for the coordination of the\ud work in Guinea Bissau. We also thank Marcio C. Valentin from the Laboratory\ud of Electron Microscopy, Institute of Biosciences, USP, and Carlos E. Jared and\ud Marta M. Antoniazzi from the Institute Butantan, São Paulo, SP, Brazil, for\ud their kindly permission to use their electron microscopic facilities. This work\ud was supported by CNPq (PROAFRICA and PROSUL) and CAPES (Programa\ud Nacional de Incentivo à Pesquisa em Parasitologia Básica). LBV was\ud postdoctoral fellow sponsored by CNPq-MCTI (PROTAX – National Program\ud of Taxonomy) and CAPES (PNPD). BRF is recipient of a scholarship from\ud CNPq (PROTAX)

EuroFlow Lymphoid Screening Tube (LST) data base for automated identification of blood lymphocyte subsets

In recent years the volume and complexity of flow cytometry data has increased substantially. This has led to a greater number of identifiable cell populations in a single measurement. Consequently, new gating strategies and new approaches for cell population definition are required. Here we describe how the EuroFlow Lymphoid Screening Tube (LST) reference data base for peripheral blood (PB) samples was designed, constructed and validated for automated gating of the distinct lymphoid (and myeloid) subsets in PB of patients with chronic lymphoproliferative disorders (CLPD). A total of 46 healthy/reactive PB samples which fulfilled predefined technical requirements, were used to construct the LST-PB reference data base. In addition, another set of 92 PB samples (corresponding to 10 healthy subjects, 51 B-cell CLPD and 31 T/NK-cell CLPD patients), were used to validate the automated gating and cell-population labeling tools with the Infinicyt software. An overall high performance of the LST-PB data base was observed with a median percentage of alarmed cellular events of 0.8% in 10 healthy donor samples and of 44.4% in CLPD data files containing 49.8% (range: 1.3–96%) tumor cells. The higher percent of alarmed cellular events in every CLPD sample was due to aberrant phenotypes (75.6% cases) and/or to abnormally increased cell counts (86.6% samples). All 18 (22%) data files that only displayed numerical alterations, corresponded to T/NK-cell CLPD cases which showed a lower incidence of aberrant phenotypes (41%) vs B-cell CLPD cases (100%). Comparison between automated vs expert-bases manual classification of normal (r2 = 0.96) and tumor cell populations (rho = 0.99) showed a high degree of correlation. In summary, our results show that automated gating of cell populations based on the EuroFlow LST-PB data base provides an innovative, reliable and reproducible tool for fast and simplified identification of normal vs pathological B and T/NK lymphocytes in PB of CLPD patients