Serum tryptase monitoring in indolent systemic mastocytosis: association with disease features and patient outcome

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Serum baseline tryptase (sBT) is a minor diagnostic criterion for systemic mastocytosis (SM) of undetermined prognostic impact. We monitored sBT levels in indolent SM (ISM) patients and investigated its utility for predicting disease behaviour and outcome. [Methods]: In total 74 adult ISM patients who were followed for ≥48 months and received no cytoreductive therapy were retrospectively studied. Patients were classified according to the pattern of evolution of sBT observed. [Results]: Overall 16/74 (22%) cases had decreasing sBT levels, 48 (65%) patients showed increasing sBT levels and 10 (13%) patients showed a fluctuating pattern. Patients with significantly increasing sBT (sBT slope ≥0.15) after 48 months of follow-up showed a slightly greater rate of development of diffuse bone sclerosis (13% vs. 2%) and hepatomegaly plus splenomegaly (16% vs. 5%), as well as a significantly greater frequency of multilineage vs. mast cells (MC)-restricted KIT mutation (p = 0.01) together with a greater frequency of cases with progression of ISM to smouldering and aggressive SM (p = 0.03), and a shorter progression-free survival (p = 0.03). [Conclusions]: Monitoring of sBT in ISM patients is closely associated with poor prognosis disease features as well as with disease progression, pointing out the need for a closer follow-up in ISM patients with progressively increasing sBT values.This work was supported by grants from the Fondo de Investigaciones Sanitarias (FIS) of the Ministerio de Ciencia e Innovación of Spain (RETICS RD06/0020/0035-FEDER and PS09/00032); Fundación Sociosanitaria de Castilla-La Mancha (FISCAM 2007/36, FISCAM 2010/008 and G-2010/C-002); Instituto de Salud Carlos III of the Ministerio de Economía y Competitividad of Spain (PI11/02399); Junta de Castilla y León (SAN/103/2011); Fundación Ramón Areces; Fundación Española de Mastocitosis (FEM 2010); Hospital Virgen de la Salud Biobank (BioB-HVS) supported by grant of RETICS RD09/0076/00074, (Toledo, Spain).Peer Reviewe

Low-count monoclonal B-cell lymphocytosis persists after seven years of follow up and is associated with a poorer outcome

Low-count monoclonal B-cell lymphocytosis is defined by the presence of very low numbers of circulating clonal B cells, usually phenotypically similar to chronic lymphocytic leukemia cells, whose biological and clinical significance remains elusive. Herein, we re-evaluated 65/91 low-count monoclonal B-cell lymphocytosis cases (54 chronic lymphocytic leukemia-like and 11 non-chronic lymphocytic leukemia-like) followed-up for a median of seven years, using high-sensitivity flow cytometry and interphase fluorescence in situ hybridization. Overall, the clone size significantly increased in 69% of low-count monoclonal B-cell lymphocytosis cases, but only one subject progressed to high-count monoclonal B-cell lymphocytosis. In parallel, the frequency of cytogenetic alterations increased over time (32% vs. 61% of cases, respectively). The absolute number of the major T-cell and natural killer cell populations also increased, but only among chronic lymphocytic leukemia-like cases with increased clone size vs. age- and sex-matched controls. Although progression to chronic lymphocytic leukemia was not observed, the overall survival of low-count monoclonal B-cell lymphocytosis individuals was significantly reduced vs. non-monoclonal B-cell lymphocytosis controls (P=0.03) plus the general population from the same region (P≤0.001), particularly among females (P=0.01); infection and cancer were the main causes of death in low-count monoclonal B-cell lymphocytosis. In summary, despite the fact that mid-term progression from low-count monoclonal B-cell lymphocytosis to high-count monoclonal B-cell lymphocytosis and chronic lymphocytic leukemia appears to be unlikely, these clones persist at increased numbers, usually carrying more genetic alterations, and might thus be a marker of an impaired immune system indirectly associated with a poorer outcome, particularly among females.This work was supported by the RD06/0020/0035 and RD12/0036/0048 grants from Red Temática de Investigación Cooperativa en Cáncer (RTICC), Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, (Madrid, Spain and FONDOS FEDER); CB16/12/00400 grant (CIBERONC, Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, (Madrid, Spain and FONDOS FEDER); the FIS PI06/0824-FEDER, PS09/02430-FEDER, PI12/00905- FEDER, DTS15/00119-FEDER, PI16/00787-FEDER and PI17/00399-FEDER grants, from the Fondo de Investigación Sanitaria of Instituto de Salud Carlos III; the GRS206/A/08 grant, (Ayuda al Grupo GR37 de Excelencia, SAN/1778/2009) from the Gerencia Regional de Salud (Consejería de Educación and Consejería de Sanidad of Castilla y León, Valladolid, Spain) and the SA079U14 grant (Consejería de Educación and Consejería de Sanidad of Castilla y León, Valladolid, Spain). ML Gutiérrez is supported by grant PTA2014-09963-I from the Instituto de Salud Carlos III

The nature of circulating CD27+CD43+ B cells

Letter to the Editor.-- et al.M.C. van Zelm is supported by fellowships from the Erasmus University Rotterdam (EUR-Fellowship) and the Erasmus MC, and by Veni grant 916.110.90 from ZonMW/NWO.Peer Reviewe

Evaluation of the WHO criteria for the classification of patients with mastocytosis

Diagnosis and classification of mastocytosis is currently based on the World Health Organization (WHO) criteria. Here, we evaluate the utility of the WHO criteria for the diagnosis and classification of a large series of mastocytosis patients (n=133), and propose a new algorithm that could be routinely applied for refined diagnosis and classification of the disease. Our results confirm the utility of the WHO criteria and provide evidence for the need of additional information for (1) a more precise diagnosis of mastocytosis, (2) specific identification of new forms of the disease, (3) the differential diagnosis between cutaneous mastocytosis vs systemic mastocytosis, and (4) improved distinction between indolent systemic mastocytosis and aggressive systemic mastocytosis. Based on our results, a new algorithm is proposed for a better diagnostic definition and prognostic classification of mastocytosis, as confirmed prospectively in an independent validation series of 117 mastocytosis patients.This work was supported by grants from the Fondo de Investigaciones Sanitarias (FIS) of the Ministerio de Ciencia e Innovación of Spain (PS09/00032 and RETICS RD06/0020/0035-FEDER); Junta de Comunidades de Castilla La Mancha (FISCAM 2007/36, FISCAM 2008/46). Junta de Castilla y León (Grant SAN1778/2009 and GR37); ACG-M is supported by a grant from FIS/FEDER (CP03/00035); CT was supported by a grant from the Fundaçcâo para a Ciência e Tecnologia (FCT) of Portugal (SFRH/BD/ 17545/2004) and by a grant from the Fondo de Investigaciones Sanitarias (FIS) of the Ministerio de Ciencia e Innovación of Spain (PI08/90881).Peer Reviewe

Optimization and testing of dried antibody tube: The EuroFlow LST and PIDOT tubes as examples

Within EuroFlow, we recently developed screening tubes for hematological malignancies and immune deficiencies. Pipetting of antibodies for such 8-color 12-marker tubes however is time-consuming and prone to operational mistakes. We therefore evaluated dried formats of the lymphocytosis screening tube (LST) and of the primary immune deficiency orientation tube (PIDOT). Both tubes were evaluated on normal and/or on patient samples, comparing the mean fluorescence intensity of specific lymphocyte populations. Our data show that the dried tubes and liquid counterparts give highly comparable staining results, particularly when analyzed in multidimensional plots. In addition, the use of dried tubes may result in a reduced staining variability between different samples and thereby contributes to the generation of more robust data. Therefore, by using ready-to-use reagents in a dried single test tube format, the laboratory efficiency and quality will be improved

Ex vivo identification and characterization of a population of CD13high CD105+ CD45- mesenchymal stem cells in human bone marrow

Introduction: Mesenchymal stem cells (MSCs) are multipotent cells capable of self-renewal and multilineage differentiation. Their multipotential capacity and immunomodulatory properties have led to an increasing interest in their biological properties and therapeutic applications. Currently, the definition of MSCs relies on a combination of phenotypic, morphological and functional characteristics which are typically evaluated upon in vitro expansion, a process that may ultimately lead to modulation of the immunophenotypic, functional and/or genetic features of these cells. Therefore, at present there is great interest in providing markers and phenotypes for direct in vivo and ex vivo identification and isolation of MSCs. Methods: Multiparameter flow cytometry immunophenotypic studies were performed on 65 bone marrow (BM) samples for characterization of CD13high CD105+ CD45- cells. Isolation and expansion of these cells was performed in a subset of samples in parallel to the expansion of MSCs from mononuclear cells following currently established procedures. The protein expre

The presence of CLL-associated stereotypic B cell receptors in the normal BCR repertoire from healthy individuals increases with age

__Background:__ Aging is known to induce immunosenescence, resulting in alterations in both the innate and adaptive immune system. Here we evaluated the effects of aging on B cell subsets in peripheral blood of 155 immunologically healthy individuals in four age categories (range 20-95y) via multi-parameter flow cytometry. Furthermore, we studied the naive and antigen-experienced B cell receptor (BCR) repertoire of different age groups and compared it to the clonal BCR repertoire of chronic lymphocytic leukemia (CLL), a disease typically presenting in elderly individuals. __Results:__ Total num

Heme-Oxygenases during Erythropoiesis in K562 and Human Bone Marrow Cells

In mammalian cells, heme can be degraded by heme-oxygenases (HO). Heme-oxygenase 1 (HO-1) is known to be the heme inducible isoform, whereas heme-oxygenase 2 (HO-2) is the constitutive enzyme. Here we investigated the presence of HO during erythroid differentiation in human bone marrow erythroid precursors and K562 cells. HO-1 mRNA and protein expression levels were below limits of detection in K562 cells. Moreover, heme was unable to induce HO-1, at the protein and mRNA profiles. Surprisingly, HO-2 expression was inhibited upon incubation with heme. To evaluate the physiological relevance of these findings, we analyzed HO expression during normal erythropoiesis in human bone marrow. Erythroid precursors were characterized by lack of significant expression of HO-1 and by progressive reduction of HO-2 during differentiation. FLVCR expression, a recently described heme exporter found in erythroid precursors, was also analyzed. Interestingly, the disruption in the HO detoxification system was accompanied by a transient induction of FLVCR. It will be interesting to verify if the inhibition of HO expression, that we found, is preventing a futile cycle of concomitant heme synthesis and catabolism. We believe that a significant feature of erythropoiesis could be the replacement of heme breakdown by heme exportation, as a mechanism to prevent heme toxicity

Data_Sheet_2_Quantitative proteomics of small numbers of closely-related cells: Selection of the optimal method for a clinical setting.zip

Supplementary Table S10. Comparative analysis of -omics platforms Supplementary Table S10. Comparative analysis of -omics platforms Supplementary Table S7.xlsx Supplementary Table S8.xlsx Supplementary Table S9.xlsxMass spectrometry (MS)-based proteomics profiling has undoubtedly increased the knowledge about cellular processes and functions. However, its applicability for paucicellular sample analyses is currently limited. Although new approaches have been developed for single-cell studies, most of them have not (yet) been standardized and/or require highly specific (often home-built) devices, thereby limiting their broad implementation, particularly in non-specialized settings. To select an optimal MS-oriented proteomics approach applicable in translational research and clinical settings, we assessed 10 different sample preparation procedures in paucicellular samples of closely-related cell types. Particularly, five cell lysis protocols using different chemistries and mechanical forces were combined with two sample clean-up techniques (C18 filter- and SP3-based), followed by tandem mass tag (TMT)-based protein quantification. The evaluation was structured in three phases: first, cell lines from hematopoietic (THP-1) and non-hematopoietic (HT-29) origins were used to test the approaches showing the combination of a urea-based lysis buffer with the SP3 bead-based clean-up system as the best performer. Parameters such as reproducibility, accessibility, spatial distribution, ease of use, processing time and cost were considered. In the second phase, the performance of the method was tested on maturation-related cell populations: three different monocyte subsets from peripheral blood and, for the first time, macrophages/microglia (MAC) from glioblastoma samples, together with T cells from both tissues. The analysis of 50,000 cells down to only 2,500 cells revealed different protein expression profiles associated with the distinct cell populations. Accordingly, a closer relationship was observed between non-classical monocytes and MAC, with the latter showing the co-expression of M1 and M2 macrophage markers, although pro-tumoral and anti-inflammatory proteins were more represented. In the third phase, the results were validated by high-end spectral flow cytometry on paired monocyte/MAC samples to further determine the sensitivity of the MS approach selected. Finally, the feasibility of the method was proven in 194 additional samples corresponding to 38 different cell types, including cells from different tissue origins, cellular lineages, maturation stages and stimuli. In summary, we selected a reproducible, easy-to-implement sample preparation method for MS-based proteomic characterization of paucicellular samples, also applicable in the setting of functionally closely-related cell populations.Peer reviewe

Harmonization of light scatter and fluorescence flow cytometry profiles obtained after staining peripheral blood leucocytes for cell surface-only versus intracellular antigens with the fix & perm™ reagent

Staining for intracellular markers with the Fix & Perm™ reagent is associated with variations in the scatter properties of leucocytes, limiting automated analysis of flow cytometry (FCM) data. Here, we investigated those variables significantly contributing to changes in the light scatter, autofluorescence, and bcl2 staining characteristics of peripheral blood (PB) leucocytes, after fixation with Fix & Perm™. Our major aim was to evaluate a new mathematical approach for automated harmonization of FCM data from datafiles corresponding to aliquots of a sample treated with cell-surface-only versus Fix & Perm intracellular staining techniques. Overall, neither the anticoagulant used nor sample storage for 15 min were used) had a minimum impact on the FCM properties of PB leucocytes. Conversely, changes in cell/protein concentrations and the fixative/sample (vol/vol) ratio had a clear impact on the light scatter features of some populations of leucocytes. Accordingly, lower cell/protein concentrations were associated with lower scatter values, particularly for the neutrophils. Such changes could be partially corrected through the use of higher fixative to sample volume ratios. Despite the variable changes detected between aliquots of the same sample treated with cell surface-only versus intracellular staining procedures, the new mathematical approach here proposed and evaluated for automated harmonization of common parameters in both datafiles, could correct the FCM profiles of leucocytes derived from cells undergoing conventional fixation/permeabilization procedures, and made them indistinguishable from those corresponding to aliquots of the same sample treated with cell-surface-only staining techniques. © 2009 Clinical Cytometry Society.Grant sponsor: Spanish Network of Cancer Research Centers (Red Temática de Investigación Cooperativa en Cáncer (RTICC)), Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Science and Innovations (Madrid, Spain); Grant number: RD06/0020/0035; Grant sponsor: Fondo de Investigación Sanitaria, Spanish Ministry of Science and Innovations (Madrid, Spain); Grant number: FIS 08/90881; Grant sponsor: Spanish Ministry of Science and Innovations (Madrid, Spain), CAPES/Ministério da Educaçâo (Brasília, Brazil) (Programa Hispano-Brasileño de Cooperación Universitaria); Grant number: PHB 2004-0800-PC; Grant sponsor: European Commission (EuroFlow Consortium); Grant number: LSHB-CT-2006-018708; Grant sponsor: CNPq-Brazilian National Research Council, Brasília, Brazil; Grant numbers: 305306/2004-9, 558147/2008-9 PDP, 478234/2007-4; Grant sponsor: FAPERJ-Fundaçâo de amparo à pesquisa do Rio de Janeiro, (Rio de Janeiro, Brazil); Grant numbers: E-26/110.301/2007, E-26/ 102-781/2008 CNE, 03/2006; Grant sponsor: CNPq-Brazilian National Research Council, Brasília, Brazil; Grant number: 558147/2008-9 PDP; Grant sponsor: Acción Transversal del Ca´ncer Project (Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Science and Innovations (Madrid, Spain)); Cancer Research Foundation of the University of Salamanca (Salamanca, Spain); Fundación Marcelino Botín (Madrid, Spain); Grant sponsor: Consejeria de Educación, Junta de Castilla y León, Valladolid, Spain; Grant number: SA016A09.Peer Reviewe