EuroFlow antibody panels for standardized n-dimensional flow cytometric immunophenotyping of normal, reactive and malignant leukocytes

Most consensus leukemia lymphoma antibody panels consist of lists of markers based on expert opinions, but they have not been validated. Here we present the validated EuroFlow 8-color antibody panels for immunophenotyping of hematological malignancies. The single-tube screening panels and multi-tube classification panels fit into the EuroFlow diagnostic algorithm with entries defined by clinical and laboratory parameters. The panels were constructed in 2-7 sequential design-evaluation-redesign rounds, using novel Infinicyt software tools for multivariate data analysis. Two groups of markers are combined in each 8-color tube: (i) backbone markers to identify distinct cell populations in a sample, and (ii) markers for characterization of specific cell populations. In multi-tube panels, the backbone markers were optimally placed at the same fluorochrome position in every tube, to provide identical multidimensional localization of the target cell population(s). The characterization markers were positioned according to the diagnostic utility of the combined markers. Each proposed antibody combination was tested against reference databases of normal and malignant cells from healthy subjects and WHO-based disease entities, respectively. The EuroFlow studies resulted in validated and flexible 8-color antibody panels for multidimensional identification and characterization of normal and aberrant cells, optimally suited for immunophenotypic screening and classification of hematological malignancies

Flow cytometric immunobead assay for fast and easy detection of PML-RARA fusion proteins for the diagnosis of acute promyelocytic leukemia

The PML-RARA fusion protein is found in approximately 97% of patients with acute promyelocytic leukemia (APL). APL can be associated with life-threatening bleeding complications when undiagnosed and not treated expeditiously. The PML-RARA fusion protein arrests maturation of myeloid cells at the promyelocytic stage, leading to the accumulation of neoplastic promyelocytes. Complete remission can be obtained by treatment with all-trans-retinoic acid (ATRA) in combination with chemotherapy. Diagnosis of APL is based on the detection of t(15;17) by karyotyping, fluorescence in situ hybridization or PCR. These techniques are laborious and demand specialized laboratories. We developed a fast (performed within 4-5 h) and sensitive (detection of at least 10% malignant cells in normal background) flow cytometric immunobead assay for the detection of PML-RARA fusion proteins in cell lysates using a bead-bound anti-RARA capture antibody and a phycoerythrin-conjugated anti-PML detection antibody. Testing of 163 newly diagnosed patients (including 46 APL cases) with the PML-RARA immunobead assay showed full concordance with the PML-RARA PCR results. As the applied antibodies recognize outer domains of the fusion protein, the assay appeared to work independently of the PML gene break point region. Importantly, the assay can be used in parallel with routine immunophenotyping for fast and easy diagnosis of APL

Final results of a phase I radioimmunotherapy trial using (186)Re-epratuzumab for the treatment of patients with non-Hodgkin's lymphoma.

PURPOSE: Radioimmunotherapy (RIT) is an effective, new treatment modality for non-Hodgkin's lymphoma (NHL). The aim of this study was to determine the maximum tolerated dose and a first impression of the therapeutic potential of (186)Re-epratuzumab in patients with NHL. EXPERIMENTAL DESIGN: Patients with relapsed or refractory CD22-positive NHL of diverse histopathology and prior treatments received (99m)Tc-labeled epratuzumab (anti-CD22 IgG1), followed by RIT with (186)Re-epratuzumab 1 week later. Dose escalation of RIT was started at 0.5 GBq/m(2). Three patients were entered per dose level. If no dose-limiting toxicity occurred, the dose was increased by 0.5 GBq/m(2); otherwise three additional patients were included on that dose level. RESULTS: A total of 18 patients received a diagnostic dose of (99m)Tc-epratuzumab. Fifteen patients were actually treated with (186)Re-epratuzumab at four different dose levels, 0.5, 1.0, 1.5, and 2.0 GBq/m(2). During or after infusion of (186)Re-epratuzumab, no adverse reactions were seen. In all patients, a transient decrease of leukocyte and platelet levels was observed 1 month after treatment. At the 1.5-GBq/m(2) dose level, one grade 4 hematological toxicity was observed. At the highest dose level of 2 GBq/m(2), no grade 4 hematological toxicity was seen, but WBC and platelet counts of two of the three patients did not recover completely. One patient had a complete remission lasting 4 months. Four patients had a partial remission, lasting 3, 3, 6, and 14 months, respectively. Four patients had stable disease for 3, 3, 7, and 9 months, respectively. CONCLUSIONS: (186)Re-epratuzumab at a dose of 2.0 GBq/m(2) is well tolerated without major toxicity. A single dose of (186)Re-epratuzumab led to objective responses in 5 of 15 treated patients

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

Immunochemical and mass-spectrometry-based serum hepcidin assays for iron metabolism disorders.

Contains fulltext : 88178.pdf (publisher's version ) (Closed access)BACKGROUND: Hepcidin is an iron-regulatory peptide hormone that consists of 3 isoforms: bioactive hepcidin-25, and inactive hepcidin-22 and hepcidin-20. Hepcidin is instrumental in the diagnosis and monitoring of iron metabolism disorders, but reliable methods for its quantification in serum are sparse, as is knowledge of their relative analytical strengths and clinical utility. METHODS: We developed a competitive (c)-ELISA and an immunocapture TOF mass-spectrometry (IC-TOF-MS) assay. Exploiting these 2 methods and our previously described weak cation exchange (WCX)-TOF-MS assay, we measured serum hepcidin concentrations in 186 patients with various disorders of iron metabolism and in 23 healthy controls. RESULTS: We found that (a) the relative differences in median hepcidin concentrations in various diseases to be similar, although the absolute concentrations measured with c-ELISA and WCX-TOF-MS differed; (b) hepcidin isoforms contributed to differences in hepcidin concentrations between methods, which were most prominent in patients with chronic kidney disease; and (c) hepcidin concentrations measured by both the c-ELISA and IC-TOF-MS correlated with ferritin concentrations <60 mug/L, and were suitable for distinguishing between iron deficiency anemia (IDA) and the combination of IDA and anemia of chronic disease. CONCLUSIONS: c-ELISA is the method of choice for the large-scale quantification of serum hepcidin concentrations, because of its low limit of detection, low cost, and high-throughput. Because of its specificity for bioactive hepcidin-25, WCX-TOF-MS can be regarded as a valuable special-purpose assay for disorders with variable concentrations of hepcidin isoforms, such as chronic kidney disease.1 oktober 201

Business process analysis with ProM

This demonstration paper describes the ProM process mining tool. Process mining techniques attempt to extract non-trivial and useful process information from so-called "event logs". ProM allows for the discovery of different process perspectives (e.g., control-flow, time, resources, and data) and supports related techniques such as control-flow mining, performance analysis, resource analysis, conformance checking, verification, etc. This makes ProM a practical and versatile tool for business process analysis and discovering

Human peripheral blood B-Cell compartments: A crossroad in B-cell traffic

A relatively high number of different subsets of B-cells are generated through the differentiation of early B-cell precursors into mature B-lymphocytes in the bone marrow (BM) and antigen-triggered maturation of germinal center B-cells into memory B-lymphocytes and plasmablasts in lymphoid tissues. These B-cell subpopulations, which are produced in the BM and lymphoid tissues, recirculate through peripheral blood (PB), into different tissues including mucosa and the BM, where long-livi

Business process analysis with ProM

This demonstration paper describes the ProM process mining tool. Process mining techniques attempt to extract non-trivial and useful process information from so-called "event logs". ProM allows for the discovery of different process perspectives (e.g., control-flow, time, resources, and data) and supports related techniques such as control-flow mining, performance analysis, resource analysis, conformance checking, verification, etc. This makes ProM a practical and versatile tool for business process analysis and discovering