Search

Objective There is a critical need for development of biomarkers to noninvasively monitor for lung transplant rejection. We investigated the potential of circulating donor lung-specific exosome profiles for time sensitive diagnosis of acute rejection in a rat orthotopic lung transplant model. Methods Left lungs from Wistar transgenic rats expressing human CD63-GFP, an exosome marker, were transplanted into fully MHC-mismatched Lewis recipients or syngeneic controls. Recipient blood was collected between 4 hours and 10 days after transplantation and plasma was processed for exosome isolation by size exclusion column chromatography and ultracentrifugation. Circulating donor exosomes were profiled using anti-human CD63 antibody quantum dot on the nanoparticle detector, and via GFP trigger on the nanoparticle flow cytometer (FACS). Results In syngeneic controls, steady state levels of circulating donor exosomes were detected at all post-transplant time points. Allogeneic grafts lost perfusion by day 8, consistent with acute rejection. Levels of circulating donor exosomes peaked on day 1, decreased significantly by day 2, and then reached baseline levels by day 3. Notably, decrease in peripheral donor exosome levels occurred before grafts had histological evidence of acute rejection. Conclusions Circulating donor lung-specific exosome profiles enable an early detection of acute rejection before histologic manifestation of injury to the pulmonary allograft. As acute rejection episodes are a major risk factor for the development of chronic lung allograft dysfunction, this biomarker may provide a novel noninvasive diagnostic platform that can translate into earlier therapeutic intervention for lung transplant patients.

BACKGROUND We previously reported the development of a novel high dimensional cytomic assay, the Vascular Health Profile (VHP) based on measurements of angiogenic circulating hematopoietic stem and progenitor cells (CHSPCAng ) and extracellular vesicles (EVs), that discovered a unique signature, differentiating the vascular status of diabetics and normal healthy controls. Here, we present data from a 3-year follow-up to evaluate the power of the VHP to identify individuals at risk for cardiovascular (CV) events. METHODS The original data were generated as previously described by measuring a broad panel of progenitor cells and EVs and profiled using cytometric fingerprinting. Subjects were classified into groups according to the occurrence of adjudicated CV events including myocardial infarction, stroke, major adverse cardiovascular events, revascularization, and irregular rhythm. Cross-validated Linear Discriminate Analysis (LDA) models were constructed and used to predict the occurrence of events, and were evaluated for predictive accuracy (AUC, area under the curve) using receiver operating characteristic (ROC) analysis. RESULTS Over the period of this analysis, follow-up data was obtained on 87 subjects, with 32 events occurring overall, and only in the diabetic group. In all cases, the VHP added significant predictive power, in the form of ROC analysis, for all evaluated outcomes with the exception of irregular rhythm. CONCLUSIONS The VHP, a relatively simple blood test, can provide sensitive and clinically relevant information on the vascular status of a patient that may be useful for a variety of applications including drug development, clinical risk assessment, and companion diagnostics. © 2015 International Clinical Cytometry Society.

Intra-amniotic infection/inflammation are major causes of spontaneous preterm labor and delivery. However, diagnosis of intra-amniotic infection is challenging because most are subclinical and amniotic fluid (AF) cultures take several days before results are available. Several tests have been proposed for the rapid diagnosis of microbial invasion of the amniotic cavity (MIAC) or intra-amniotic inflammation. The aim of this study was to examine the diagnostic performance of the AF Mass Restricted (MR) score in comparison with interleukin-6 (IL-6) and matrix metalloproteinase-8 (MMP-8) for the identification of MIAC or inflammation.AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 100). Intra-amniotic inflammation was defined as100 white blood cells/mm(3) (WBCs) in AF; MIAC was defined as a positive AF culture. AF IL-6 and MMP-8 were determined using ELISA. The MR score was obtained using the Surface-Enhanced Laser Desorption Ionization Time of Flight (SELDI-TOF) mass spectrometry. Sensitivity and specificity were calculated and logistic regression models were fit to construct receiver-operating characteristic (ROC) curves for the identification of each outcome. The McNemar's test and paired sample non-parametric statistical techniques were used to test for differences in diagnostic performance metrics.(1) The prevalence of MIAC and intra-amniotic inflammation was 34% (34/100) and 40% (40/100), respectively; (2) there were no significant differences in sensitivity of the three tests under study (MR score, IL-6 or MMP-8) in the identification of either MIAC or intra-amniotic inflammation (using the following cutoffs: MR score2, IL-611.4 ng/mL, and MMP-823 ng/mL); (3) there was no significant difference in the sensitivity among the three tests for the same outcomes when the false positive rate was fixed at 15%; (4) the specificity for IL-6 was not significantly different from that of the MR score in identifying either MIAC or intra-amniotic inflammation when using previously reported thresholds; and (5) there were no significant differences in the area under the ROC curve when comparing the MR score, IL-6 or MMP-8 in the identification of these outcomes.IL-6 and the MR score have equivalent diagnostic performance in the identification of MIAC or intra-amniotic inflammation. Selection from among these three tests (MR score, IL-6 and MMP-8) for diagnostic purposes should be based on factors such as availability, reproducibility, and cost. The MR score requires a protein chip and a SELDI-TOF instrument which are not widely available or considered "state of the art". In contrast, immunoassays for IL-6 can be performed in the majority of clinical laboratories.

Background An inexpensive and accurate blood test does not currently exist that can evaluate the cardiovascular health of a patient. This study evaluated a novel high dimensional flow cytometry approach in combination with cytometric fingerprinting (CF), to comprehensively enumerate differentially expressed subsets of pro-angiogenic circulating progenitor cells (CPCs), involved in the repair of vasculature, and microparticles (MPs), frequently involved in inflammation and thrombosis. CF enabled discovery of a unique pattern, involving both MPs and CPCs and generated a personalized signature of vascular health, the vascular health profile (VHP). Methods Levels of CPCs and MPs were measured with a broad panel of cell surface markers in a population with atherosclerosis and type 2 diabetes mellitus (DM) and age-similar Healthy controls (HC) using an unbiased computational approach, termed CF. Results Circulating hematopoietic stem and progenitor cell (CHSPCAng) levels were detected at significantly lower concentrations in DM (P < 0.001), whereas levels of seven phenotypically distinct MPs were present at significantly higher concentrations in DM patients and one MP subset was present at significantly lower concentration in DM patients. Collectively, the combination of CHSPCAng and MP levels was more informative than any one measure alone. Conclusions This work provides the basis for a personalized cytomic vascular health profile that may be useful for a variety of applications including drug development, clinical risk assessment and companion diagnostics. © 2013 International Clinical Cytometry Society

Endothelial progenitor cells (EPCs) are thought to be important for maintaining normal vascular function. We conducted a prospective study evaluating the effect of the erythropoiesis-stimulating agent darbepoetin alfa on EPCs and vascular function in patients with chronic kidney disease (CKD), with or without diabetes. Thirty subjects with CKD (20 subjects with type II diabetes mellitus and 10 without diabetes mellitus) received weekly subcutaneous administration of darbepoetin alfa for 4 weeks. EPCs were measured at baseline and 2 and 4 weeks after drug administration. Vascular function was measured with brachial ultrasound and cell activity was measured with a cell proliferation assay. Cells expressing CD133, CD34, CD146 and CD146/31 were significantly elevated (all p < 0.05), flow-mediated vasodilatation increased 2.1%, 95% CI: (0.4%, 3.8%) and colony-forming units increased twofold, 95% CI: (1.7, 2.3) after 4 weeks of treatment with darbepoetin alfa. Subjects with diabetes exhibited an increase in a subset of EPCs (CD133 + and 34+, p < 0.01 and p = 0.06, respectively), vasodilatation and proliferation. In conclusion, the administration of darbepoetin alfa for 4 weeks increased a subset of EPCs, improved endothelial function and increased cell proliferation, including those with diabetes, which is consistent with a favorable improvement in vascular health.

Background Psoriasis, especially when severe, is a risk factor for cardiometabolic disease beyond traditional risk factors. The mechanism of atherogenesis in psoriasis remains unknown. Cell membrane vesicles (ie, microparticles), released upon cell activation or apoptosis, have recently been associated with cardiometabolic disease and may play a pathogenic role. Microparticle levels, particularly from endothelial cells and platelets, are elevated in patients with cardiovascular disorders, metabolic syndrome, other inflammatory diseases, autoimmune conditions, and have been shown to be predictive of cardiovascular outcomes. Methods and Results Concentrations of microparticles with positive expression for any of 7 cell surface markers (Annexin V, CD 3, CD 31, CD 41a, CD 64, CD 105, and CD 144) were measured in blood samples from psoriasis patients (n=53) and control subjects without psoriasis (n=41). Platelet‐free plasma was separated from whole blood by one‐step centrifugation for microparticle analysis. Microparticles were fluorescently labeled and characterized by flow cytometry. Higher concentrations of CD 105 (5.5/μL versus 2.5/μL, P CD 31 (31/μL versus 18/μL, P =0.002), CD 41a (50/μL versus 22/μL, P CD 64 (5.0/μL versus 4.1/μL, P =0.02) singly positive microparticles corresponding to endothelial cell‐, platelet‐, and monocyte/macrophage‐derived microparticles, respectively, were found in psoriasis patients compared with controls. These differences persisted after adjustment for traditional cardiometabolic risk factors including body mass index. Conclusions Increased microparticle concentrations, independent of cardiometabolic risk factors, in patients with psoriasis suggest that the presence of increased endothelial cell, platelet, and monocyte/macrophage activation with cell turnover may contribute to the heightened atherogenesis associated with psoriasis.

A computer-microscope system is described for use in capturing accurate, quantitative schematic (map) information from anatomical tissue sections. The system provides a rapid and convenient environment for acquisition and analysis of complex structures spread over large 3-D regions of the tissue. As a consequence of the complexity and subtlety of tissue analysis, most of the data acquisition functions of the system involve tight coupling between the hardware and the microscopist to preserve access to human judgment and intelligence. The instrument profoundly affects the ease and accuracy of neurobiological data analysis, making it practical to address previously inaccessible problems. Examples of data analyzed using the system are shown.

OBJECTIVE: Examination of the amniotic fluid (AF) proteome has been previously attempted to identify useful biomarkers in predicting the outcome of preterm labor (PTL). Isobaric Tag for Relative and Absolute Quantitation (iTRAQ™) labeling allows direct ratiometric comparison of relative abundance of identified protein species among multiplexed samples. The purpose of this study was to apply, for the first time, the combination of iTRAQ and tandem mass spectrometry to identify proteins differentially regulated in AF samples of women with spontaneous PTL and intact membranes with and without intra-amniotic infection/inflammation (IAI). METHODS: A cross-sectional study was designed and included AF samples from patients with spontaneous PTL and intact membranes in the following groups: 1) patients without IAI who delivered at term (n=26); 2) patients who delivered preterm without IAI (n=25); and 3) patients with IAI (n=24). Proteomic profiling of AF samples was performed using a workflow involving tryptic digestion, iTRAQ labeling and multiplexing, strong cation exchange fractionation, and liquid chromatography tandem mass spectrometry. Twenty-five separate 4-plex samples were prepared and analyzed. RESULTS: Collectively, 123,011 MS(2) spectra were analyzed, and over 25,000 peptides were analyzed by database search (X!Tandem and Mascot), resulting in the identification of 309 unique high-confidence proteins. Analysis of differentially-present iTRAQ reporter peaks revealed many proteins that have been previously reported to be associated with preterm delivery with IAI. Importantly, many novel proteins were found to be up-regulated in the AF of patients with PTL and IAI including Leukocyte elastase precursor, Thymosin-like 3 and 14-3-3 protein isoforms. Moreover, we observed differential expression of proteins in AF of patients who delivered preterm in the absence of IAI in comparison with those with PTL who delivered at term including Mimecan precursor, Latent-transforming growth factor beta-binding protein isoform 1L precursor, and Resistin. These findings have been confirmed for Resistin in an independent cohort of samples using ELISA. Gene Ontology enrichment analysis was employed to reveal families of proteins participating in distinct biological processes. We identified enrichment for host defense, anti-apoptosis, metabolism/catabolism and cell and protein mobility, localization and targeting. CONCLUSIONS: (1) Proteomics with iTRAQ labeling is a profiling tool capable of revealing differential expression of proteins in AF; (2) We discovered eighty-two proteins differentially expressed in three clinical subgroups of premature labor, sixty-seven which were heretofore unknown. Of particular importance is the identification of proteins differentially expressed in AF from women who delivered preterm in the absence of IAI. This is the first report of the positive identification of biomarkers in this subgroup of patients.

A new software package called flowFP for the analysis of flow cytometry data is introduced. The package, which is tightly integrated with other Bioconductor software for analysis of flow cytometry, provides tools to transform raw flow cytometry data into a form suitable for direct input into conventional statistical analysis and empirical modeling software tools. The approach of flowFP is to generate a description of the multivariate probability distribution function of flow cytometry data in the form of a “fingerprint.” As such, it is independent of a presumptive functional form for the distribution, in contrast with model-based methods such as Gaussian Mixture Modeling. FlowFP is computationally efficient and able to handle extremely large flow cytometry data sets of arbitrary dimensionality. Algorithms and software implementation of the package are described. Use of the software is exemplified with applications to data quality control and to the automated classification of Acute Myeloid Leukemia.

Intra-amniotic infection/inflammation (IAI) is one of the most important mechanisms of disease in preterm birth. Resistin is an adipocytokine that has been linked to insulin resistance, diabetes, obesity and inflammation. The objective of this study was to determine if resistin is present in amniotic fluid (AF) and if its concentration changes with gestational age, in the presence of labour, and in IAI in patients with spontaneous preterm labour (PTL) and intact membranes, preterm prelabour rupture of membranes (PPROM) and clinical chorioamnionitis.This cross-sectional study included 648 patients in the following groups: (1) women in the mid-trimester of pregnancy (14-18 weeks) who underwent amniocentesis for genetic indications and delivered a normal neonate at term (n = 61); (2) normal pregnant women at term with (n = 49) and without (n = 50) spontaneous labour; (3) patients with an episode of PTL and intact membranes who were classified into: (a) PTL who delivered at term (n = 153); (b) PTL who delivered preterm (37 weeks gestation) without IAI (n = 108); and (c) PTL with IAI (n = 84); (4) women with PPROM with (n = 47) and without (n = 44) IAI; and (5) patients with clinical chorioamnionitis at term with (n = 22) and without (n = 30) microbial invasion of the amniotic cavity. Resistin concentration in AF was determined by enzyme-linked immunoassay. Non-parametric statistics were used for analyses.(1) Resistin was detected in all AF samples; (2) the median AF resistin concentration at term was significantly higher than in the mid-trimester (23.6 ng/mL vs. 10 ng/mL; p0.001); (3) among patients with PTL, the median AF resistin concentration was significantly higher in patients with IAI than in those without IAI (144.9 ng/mL vs. 18.7 ng/mL; p0.001) and those with PTL and intact membranes who delivered at term (144.9 ng/mL vs. 16.3 ng/mL; p0.001); (4) patients with PPROM with IAI had a significantly higher median AF resistin concentration than those without IAI (132.6 ng/mL vs. 13 ng/mL; p0.001); (5) no significant differences were observed in the median AF resistin concentration between patients with spontaneous labour at term and those at term not in labour (28.7 ng/mL vs. 23.6 ng/mL; p = 0.07); and (6) AF resistin concentrationor =37 ng/mL (derived from a receiver-operating characteristic curve) had a sensitivity of 85.4% and a specificity of 94.3% for the diagnosis of intra-amniotic inflammation.Resistin is a physiologic constituent of the AF, and its concentrations in AF: (1) are significantly elevated in the presence of IAI; (2) increase with advancing gestation; and (3) do not change in the presence of spontaneous labour at term. We propose that resistin may play a role in the innate immune response against intra-amniotic infection.

Examination of the amniotic fluid proteome has been used to identify biomarkers for intra-amniotic inflammation as well as those that may be useful in predicting the outcome of preterm labor. The purpose of this study was to combine a novel computational method of pattern discovery with mass spectrometric proteomic profiling of amniotic fluid to discover biomarkers of intra-amniotic infection/inflammation (IAI).This cross-sectional study included patients with spontaneous preterm labor and intact membranes who delivered at term (n = 59) and those who delivered preterm with IAI (n = 60). Proteomic profiling was performed using surface-enhanced laser desorption/ionization (SELDI) mass spectrometry. A proteomic profile was acquired through multiple simultaneous SELDI conditions, which were combined in a single proteomic 'fingerprint' using a novel computational approach. Classification of patients based on their associated surface-enhanced laser desorption/ionization-time of flight (SELDI-TOF) mass spectra as belonging to either the class of individuals with preterm delivery with IAI or term delivery was accomplished by constructing an empirical model. The first phase in the construction of this empirical model involved the selection of adjustable parameters utilizing a training/testing subset of data. The second phase tested the generalization of the model by utilizing a blinded validation set of patients who were not employed in parameter selection.Gestational age at amniocentesis was not significantly different between the groups. Thirty-nine unique mass spectrometric peaks discriminated patients with preterm labor/delivery with IAI from those with preterm labor and term delivery. In the testing/training dataset, the classification accuracies (averaged over 100 random draws) were: 91.4% (40.2/44) for patients with preterm delivery with IAI, and 91.2% (40.1/44) for term delivery. The overall accuracy of the classification of patients in the validation dataset was 90.3% (28/31).Proteomic analysis of amniotic fluid allowed the identification of mass spectrometry features, which can distinguish patients with preterm labor with IAI from those with preterm labor without inflammation or infection who subsequently delivered at term.

Recent technological advances in flow cytometry instrumentation provide the basis for high-dimensionality and high-throughput biological experimentation in a heterogeneous cellular context. Concomitant advances in scalable computational algorithms are necessary to better utilize the information that is contained in these high-complexity experiments. The development of such tools has the potential to expand the utility of flow cytometric analysis from a predominantly hypothesis-driven mode to one of discovery, or hypothesis-generating research. A new method of analysis of flow cytometric data called Cytometric Fingerprinting (CF) has been developed. CF captures the set of multivariate probability distribution functions corresponding to list-mode data and then “flattens” them into a computationally efficient fingerprint representation that facilitates quantitative comparisons of samples. An experimental and synthetic data were generated to act as reference sets for evaluating CF. Without the introduction of prior knowledge, CF was able to “discover” the location and concentration of spiked cells in ungated analyses over a concentration range covering four orders of magnitude, to a lower limit on the order of 10 spiked events in a background of 100,000 events. We describe a new method for quantitative analysis of list-mode cytometric data. CF includes a novel algorithm for space subdivision that improves estimation of the probability density function by dividing space into nonrectangular polytopes. Additionally it renders a multidimensional distribution in the form of a one-dimensional multiresolution hierarchical fingerprint that creates a computationally efficient representation of high dimensionality distribution functions. CF supports both the generation and testing of hypotheses, eliminates sources of operator bias, and provides an increased level of automation of data analysis. © 2008 International Society for Advancement of Cytometry

Severe psoriasis is a risk factor for cardiovascular (CV) disease beyond traditional risk factors; however, the mechanism remains unknown. Recent findings suggest that cell membrane vesicles, or microparticles, which are released upon cell activation or apoptosis, are associated with CV disease and

Publisher Summary In situ hybridization histochemistry has frequently been used as a qualitative technique to detect and localize specific nucleic acid sequences in an anatomical context, without particular respect to the abundance of the detected sequence. Quantitative analysis is necessary for evaluating changes in gene expression with in situ hybridization histochemistry. The structural and functional complexity of the brain requires that this analysis be represented in an anatomical context to be meaningful. With autoradiographic film analysis, this process is efficiently carried out by the computerized densitometry and pseudocolor representation of the film images of the hybridization signal. In contrast, a quantitative analysis of autoradiographic grain density at the cellular level is more difficult. However, the high degree of anatomical specificity and resolution obtained with emulsion autoradiography should facilitate any study of the distribution and regulation of messenger RNA (mRNA) levels in heterogeneous tissues, such as the brain.