Identification of brain-enriched proteins in CSF as biomarkers of relapsing remitting multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is a clinically and biologically heterogenous disease with currently unpredictable progression and relapse. After the development and success of neurofilament as a cerebrospinal fluid (CSF) biomarker, there is reinvigorated interest in identifying other markers of or contributors to disease. The objective of this study is to probe the predictive potential of a panel of brain-enriched proteins on MS disease progression and subtype. METHODS: This study includes 40 individuals with MS and 14 headache controls. The MS cohort consists of 20 relapsing remitting (RR) and 20 primary progressive (PP) patients. The CSF of all individuals was analyzed for 63 brain enriched proteins using a method of liquid-chromatography tandem mass spectrometry. Wilcoxon rank sum test, Kruskal-Wallis one-way ANOVA, logistic regression, and Pearson correlation were used to refine the list of candidates by comparing relative protein concentrations as well as relation to known imaging and molecular biomarkers. RESULTS: We report 30 proteins with some relevance to disease, clinical subtype, or severity. Strikingly, we observed widespread protein depletion in the disease CSF as compared to control. We identified numerous markers of relapsing disease, including KLK6 (kallikrein 6, OR = 0.367, p < 0.05), which may be driven by active disease as defined by MRI enhancing lesions. Other oligodendrocyte-enriched proteins also appeared at reduced levels in relapsing disease, namely CNDP1 (carnosine dipeptidase 1), LINGO1 (leucine rich repeat and Immunoglobin-like domain-containing protein 1), MAG (myelin associated glycoprotein), and MOG (myelin oligodendrocyte glycoprotein). Finally, we identified three proteins-CNDP1, APLP1 (amyloid beta precursor like protein 1), and OLFM1 (olfactomedin 1)-that were statistically different in relapsing vs. progressive disease raising the potential for use as an early biomarker to discriminate clinical subtype. CONCLUSIONS: We illustrate the utility of targeted mass spectrometry in generating potential targets for future biomarker studies and highlight reductions in brain-enriched proteins as markers of the relapsing remitting disease stage.

A prospective, blinded study of a PF4-dependent assay for HIT diagnosis.

Heparin-induced thrombocytopenia (HIT) is a life-threatening, prothrombotic, antibody-mediated disorder. To maximize the likelihood of recovery, early and accurate diagnosis is critical. Widely available HIT assays, such as the platelet factor 4 (PF4) heparin enzyme-linked immunosorbent assay (ELISA) lack specificity, and the gold-standard carbon 14-labeled serotonin release assay (SRA) is of limited value for early patient management because it is available only through reference laboratories. Recent studies have demonstrated that pathogenic HIT antibodies selectively activate PF4-treated platelets and that a technically simpler assay, the PF4-dependent P-selectin expression assay (PEA), may provide an option for rapid and conclusive results. Based upon predefined criteria that combined 4Ts scores and HIT ELISA results, 409 consecutive adults suspected of having HIT were classified as disease positive, negative, or indeterminate. Patients deemed HIT indeterminate were considered disease negative in the primary analysis and disease positive in a sensitivity analysis. The ability of PEA and SRA to identify patients judged to have HIT was compared using receiver operating characteristic curve statistics. Using these predefined criteria, the diagnostic accuracy of PEA was high (area under the curve [AUC], 0.94; 95% confidence interval [CI], 0.87-1.0) and similar to that of SRA (AUC, 0.91; 95% CI, 0.82-1.0). In sensitivity analysis, the AUCs of PEA and SRA were also similar at 0.88 (95% CI, 0.78-0.98) and 0.86 (95% CI, 0.77-0.96), respectively. The PEA, a technically simple nonradioactive assay that uses ∼20-fold fewer platelets compared with the SRA, had high accuracy for diagnosing HIT. Widespread use of the PEA may facilitate timely and more effective management of patients with suspected HIT.

Distinct Homologous and Variant-Specific Memory B-Cell and Antibody Response Over Time After Severe Acute Respiratory Syndrome Coronavirus 2 Messenger RNA Vaccination.

The durability of protective humoral immunity after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination and infection is largely dependent on the generation and persistence of antigen-specific isotype-switched memory B cells (MBCs) and long-lived plasma cells that reside in the bone marrow and secrete high-affinity neutralizing antibodies. The reactivity of vaccine-induced MBCs to emerging clinically significant SARS-CoV-2 variants of concern (VoCs) is largely unknown. In a longitudinal cohort study (up to 6 months following coronavirus disease 2019 messenger RNA vaccination), we measured MBCs in concert with other functional antibody measures. We found statistically significant differences between the frequencies of MBCs responding to homologous and VoC (Beta, Gamma, and Delta) receptor-binding domains after vaccination that persisted over time. In concert with a waning antibody response, the reduced MBC response to VoCs could translate to a weaker subsequent recall immune response and increased susceptibility to the emerging SARS-CoV-2 variant strains after vaccination.

The Influence of Sex, Body Mass Index, and Age on Cellular and Humoral Immune Responses Against Measles After a Third Dose of Measles-Mumps-Rubella Vaccine.

BACKGROUND: A third dose of measles-mumps-rubella vaccine (MMR3) is recommended in mumps outbreak scenarios, but the immune response and the need for widespread use of MMR3 remain uncertain. Herein, we characterized measles-specific immune responses to MMR3 in a cohort of 232 healthy subjects. METHODS: Serum and peripheral blood mononuclear cells (PBMCs) were sampled at day 0 and day 28 after MMR3. Measles-specific binding and neutralizing antibodies were quantified in sera by enzyme-linked immunosorbent assay and a microneutralization assay, respectively. PBMCs were stimulated with inactivated measles virus, and the release of cytokines/chemokines was assessed by a multiplex assay. Demographic variables of subjects were examined for potential correlations with immune outcomes. RESULTS: Of the study participants, 95.69% and 100% were seropositive at day 0 and day 28, respectively. Antibody avidity significantly increased from 38.08% at day 0 to 42.8% at day 28 (P = .00026). Neutralizing antibodies were significantly enhanced, from 928.7 at day 0 to 1289.64 mIU/mL at day 28 (P = .0001). Meanwhile, cytokine/chemokine responses remained largely unchanged. Body mass index was significantly correlated with the levels of inflammatory cytokines/chemokines. CONCLUSIONS: Measles-specific humoral immune responses, but not cellular responses, were enhanced after MMR3 receipt, extending current understanding of immune responses to MMR3 and supporting MMR3 administration to seronegative or high-risk individuals.

Transcriptional signatures associated with rubella virus-specific humoral immunity after a third dose of MMR vaccine in women of childbearing age.

Multiple factors linked to host genetics/inherent biology play a role in interindividual variability in immune response outcomes after rubella vaccination. In order to identify these factors, we conducted a study of rubella-specific humoral immunity before (Baseline) and after (Day 28) a third dose of MMR-II vaccine in a cohort of 109 women of childbearing age. We performed mRNA-Seq profiling of PBMCs after rubella virus in vitro stimulation to delineate genes associated with post-vaccination rubella humoral immunity and to define genes mediating the association between prior immune response status (high or low antibody) and subsequent immune response outcome. Our study identified novel genes that mediated the association between prior immune response and neutralizing antibody titer after a third MMR vaccine dose. These genes included the following: CDC34; CSNK1D; APOBEC3F; RAD18; AAAS; SLC37A1; FAS; and JAK2. The encoded proteins are involved in innate antiviral response, IFN/cytokine signaling, B cell repertoire generation, the clonal selection of B lymphocytes in germinal centers, and somatic hypermutation/antibody affinity maturation to promote optimal antigen-specific B cell immune function. These data advance our understanding of how subjects' prior immune status and/or genetic propensity to respond to rubella/MMR vaccination ultimately affects innate immunity and humoral immune outcomes after vaccination.

Persistence of Ad26.COV2.S-associated vaccine-induced immune thrombotic thrombocytopenia (VITT) and specific detection of VITT antibodies.

Rare cases of COVID-19 vaccinated individuals develop anti-platelet factor 4 (PF4) antibodies that cause thrombocytopenia and thrombotic complications, a syndrome referred to as vaccine-induced immune thrombotic thrombocytopenia (VITT). Currently, information on the characteristics and persistence of anti-PF4 antibodies that cause VITT after Ad26.COV2.S vaccination is limited, and available diagnostic assays fail to differentiate Ad26.COV2.S and ChAdOx1 nCoV-19-associated VITT from similar clinical disorders, namely heparin-induced thrombocytopenia (HIT) and spontaneous HIT. Here we demonstrate that while Ad26.COV2.S-associated VITT patients are uniformly strongly positive in PF4-polyanion enzyme-linked immunosorbent assays (ELISAs); they are frequently negative in the serotonin release assay (SRA). The PF4-dependent p-selectin expression assay (PEA) that uses platelets treated with PF4 rather than heparin consistently diagnosed Ad26.COV2.S-associated VITT. Most Ad26.COV2.S-associated VITT antibodies persisted for >5 months in PF4-polyanion ELISAs, while the PEA became negative earlier. Two patients had otherwise unexplained mild persistent thrombocytopenia (140-150 x 103 /µL) 6 months after acute presentation. From an epidemiological perspective, differentiating VITT from spontaneous HIT, another entity that develops in the absence of proximate heparin exposure, and HIT is important, but currently available PF4-polyanion ELISAs and functional assay are non-specific and detect all three conditions. Here, we report that a novel un-complexed PF4 ELISA specifically differentiates VITT, secondary to both Ad26.COV2.S and ChAdOx1 nCoV-19, from both spontaneous HIT, HIT and commonly-encountered HIT-suspected patients who are PF4/polyanion ELISA-positive but negative in functional assays. In summary, Ad26.COV2.S-associated VITT antibodies are persistent, and the un-complexed PF4 ELISA appears to be both sensitive and specific for VITT diagnosis.

Blood volume expansion, normovolemia, and clinical outcomes in chronic human heart failure: more is better.

Expansion in blood volume (BV) is a well-recognized response to arterial underfilling secondary to impaired cardiac output in heart failure (HF). However, the effectiveness of this response in terms of outcomes remains inadequately understood. Prospective analysis was undertaken in 110 patients with HF hospitalized and treated for fluid overload. BVs were measured in a compensated state at the hospital discharge using the indicator-dilution methodology. Data were analyzed for composite 1-year HF-related mortality/first rehospitalization. Despite uniform standard of care, marked heterogeneity in BVs was identified across the cohort. The cohort was stratified by BV expansion greater than or equal to +25% above normal (51% of cohort), mild-moderate expansion (22%), and normal BV (27%). Kaplan-Meier (K-M) survival estimates and regression analyses revealed BV expansion (greater than or equal to +25%) to be associated with better event-free survival relative to normal BV (P = 0.038). Increased red blood cell mass (RBCm; RBC polycythemia) was identified in 43% of the overall cohort and 70% in BV expansion greater than or equal to +25%. K-M analysis demonstrated polycythemia to be associated with better outcomes compared with normal RBCm (P < 0.002). Persistent BV expansion to include RBC polycythemia is common and, importantly, associated with better clinical outcomes compared with normal total BV or normal RBCm in patients with chronic HF. However, compensatory BV expansion is not a uniform physiological response to the insult of HF with marked variability in BV profiles despite uniform standard of care diuretic therapy. Therefore, recognizing the variability in volume regulation pathophysiology has implications not only for impact on clinical outcomes and risk stratification but also potential for informing individualized volume management strategies.NEW & NOTEWORTHY The novel findings of this study demonstrate that intravascular volume profiles among the patients with chronic heart failure (HF) vary substantially even with similar clinical compensation. Importantly, a profile of blood volume (BV) expansion (compared with a normal BV) is associated with lower HF mortality/morbidity. Furthermore, RBC polycythemia is common and independently associated with improved outcomes. These observations support BV expansion with RBC polycythemia as a compensatory mechanism in chronic HF.

Diuresis-Related Weight Loss Reflects Interstitial Compartment Decongestion with Minimal Impact on Intravascular Volume Expansion or Outcomes in Post-Acute Heart Failure: Metrics of Decongestion and Volume Status.

BACKGROUND: Findings from heart failure (HF) studies linking diuresis-related weight loss to clinical decongestion and outcomes are mixed. Differential responses of interstitial and intravascular volume compartments to diuretic therapy and heterogeneity in volume profiles may confound the clinical interpretation of weight loss in patients with HF. METHODS AND RESULTS: Data were prospectively collected in hospitalized patients requiring diuresis. Plasma volume (PV) was measured using I-131-labelled albumin indicator-dilution methodology. The cohort was stratified by tertiles of weight loss and analyzed for interstitial fluid loss relative to changes in PV and HF-related morality or first rehospitalization. Among 92 patients, the admission PV was expanded +42% (4.7 ± 1.2 L) above normal with significant variability (14% normal PV, 18% mild-moderate expansion, and 68% with large PV expansion [>+25% above normal]). With diuresis there were proportional decreases in interstitial volume (-6.5 ± 4.4%) and PV (-7.5 ± 11%); however, absolute decreases in the PV (-254 mL, interquartile range -11 to -583 mL) were less than 10% of interstitial volume loss (-5040 mL, interquartile range -2800 to -7989 mL); greater interstitial fluid loss did not translate into better outcomes (log-rank P = .430). CONCLUSIONS: Diuresis-related decreases in weight reflect fluid loss from the interstitial compartment with only minor changes in the PV and without an impact on outcomes. Further, the degree of PV expansion at hospital admission does not drive the magnitude of the diuresis response, even with a wide spectrum of body weights; interstitial fluid overload is preferentially targeted and PV relatively preserved. Therefore, greater interstitial fluid loss reflects clinical decongestion, but not better outcomes, and a limited association with intravascular volume profiles potentially confounding weight loss as a prognostic metric in HF.

An omnibus test for differential distribution analysis of microbiome sequencing data.

Motivation: One objective of human microbiome studies is to identify differentially abundant microbes across biological conditions. Previous statistical methods focus on detecting the shift in the abundance and/or prevalence of the microbes and treat the dispersion (spread of the data) as a nuisance. These methods also assume that the dispersion is the same across conditions, an assumption which may not hold in presence of sample heterogeneity. Moreover, the widespread outliers in the microbiome sequencing data make existing parametric models not overly robust. Therefore, a robust and powerful method that allows covariate-dependent dispersion and addresses outliers is still needed for differential abundance analysis. Results: We introduce a novel test for differential distribution analysis of microbiome sequencing data by jointly testing the abundance, prevalence and dispersion. The test is built on a zero-inflated negative binomial regression model and winsorized count data to account for zero-inflation and outliers. Using simulated data and real microbiome sequencing datasets, we show that our test is robust across various biological conditions and overall more powerful than previous methods. Availability and implementation: R package is available at https://github.com/jchen1981/MicrobiomeDDA. Contact: chen.jun2@mayo.edu or zhiwei@njit.edu. Supplementary information: Supplementary data are available at Bioinformatics online.

Identification of Factors Associated with Hematology-Oncology Fellow Academic Success and Career Choice.

Factors affecting hematology-oncology trainees' academic success and career choices have not been well characterized. We performed a retrospective study of 57 hematology-oncology fellows trained at Mayo Clinic between 2008 and 2017 in an attempt to identify factors associated with success during fellowship and with career choice (academic versus private). Sex, age, residency quality, and letters of recommendation indicating a "top" applicant were not associated with hematology or oncology in-training examination (ITE) scores, research productivity (abstracts/publications during fellowship), or career choice (academic versus private). Fellows with higher United States Medical Licensing Examination (USMLE) scores were more likely to perform well on ITE, but examination scores did not predict academic productivity or academic versus private career choice. More academically productive fellows were more likely to choose academic careers. Both ITE scores and productivity were associated with receipt of national and/or institutional awards. Finally, fellows who were non-US citizens and/or international medical graduates (IMG) had higher academic productivity both pre-fellowship and during fellowship and as per the observations above were more likely to choose academic careers. In conclusion, predictors of superior knowledge differ from predictors of academic productivity/career choice, and it is important to take multiple factors into account when selecting candidates most likely to succeed during fellowship.

Intra-articular injection of a substance P inhibitor affects gene expression in a joint contracture model.

Substance P (SP), a neurotransmitter released after injury, has been linked to deregulated tissue repair and fibrosis in musculoskeletal tissues and other organs. Although SP inhibition is an effective treatment for nausea, it has not been previously considered as an anti-fibrotic therapy. Although there are extensive medical records of individuals who have used SP antagonists, our analysis of human registry data revealed that patients receiving these antagonists and arthroplasty are exceedingly rare, thus precluding a clinical evaluation of their potential effects in the context of arthrofibrosis. Therefore, we pursued in vivo studies to assess the effect of SP inhibition early after injury on pro-fibrotic gene expression and contractures in an animal model of post-traumatic joint stiffening. Skeletally mature rabbits (n = 24) underwent surgically induced severe joint contracture, while injected with either fosaprepitant (a selective SP antagonist) or saline (control) early after surgery (3, 6, 12, and 24 h). Biomechanical testing revealed that differences in mean contracture angles between the groups were not statistically significant (P = 0.27), suggesting that the drug neither mitigates nor exacerbates joint contracture. However, microarray gene expression analysis revealed that mRNA levels for proteins related to cell signaling, pro-angiogenic, pro-inflammatory, and collagen matrix production were significantly different between control and fosaprepitant treated rabbits (P < 0.05). Hence, our study demonstrates that inhibition of SP alters expression of pro-fibrotic genes in vivo. This finding will motivate future studies to optimize interventions that target SP to reduce the formation of post-traumatic joint contractures.

Platelet-predominate gene expression and reticulated platelets in nonvalvular atrial fibrillation: Effect of pulmonary veins isolation.

INTRODUCTION: Reticulated platelet (RP) content is increased in nonvalvular atrial fibrillation (NVAF). The purpose of this study was to determine if platelet content, morphology, and RP proportion are modulated by platelet genes. METHODS AND RESULTS: Expression of six platelet-predominate genes impacting platelet formation and release, platelet count, and RP content was assessed in NVAF patients before and 3-4 months after pulmonary veins isolation (PVI) and compared to normal sinus rhythm (NSR) controls. RNA from isolated platelets was reverse-transcribed assayed against selected genes utilizing real-time qPCR, and expressed as mean cycle threshold (ΔCt) using beta-2-microglobulin as endogenous control. RP content was assessed by flow cytometry. A fourfold lower expression of CFL1 gene coding for nonmuscle cofilin (7.8 ± 0.9 vs. 5.7 ± 1.6, P < 0.001) and twofold lower expression of four other genes were associated with similar platelet counts but fourfold higher (28.7+7.0 vs. 6.7+5.4, P < 0.001) RP content (%) in 97 NVAF cases compared to 51 NSR controls. Three to 4 months after PVI, RP decreased by 28%, while CFL1 gene expression increased over twofold but TUBA4A gene expression decreased almost twofold; NFE2 and MYL6 gene expression remained unchanged. CONCLUSIONS: NVAF is associated with notable downregulation of genes directing platelet production and size but increased RP content. PVI impacts the expression of many of these genes, implying a direct relationship between atrial fibrillation and platelet biogenesis.

Genome-wide associations of CD46 and IFI44L genetic variants with neutralizing antibody response to measles vaccine.

Population-based studies have revealed 2-10% measles vaccine failure rate even after two vaccine doses. While the mechanisms behind this remain unknown, we hypothesized that host genetic factors are likely to be involved. We performed a genome-wide association study of measles specific neutralizing antibody and IFNγ ELISPOT response in a combined sample of 2872 subjects. We identified two distinct chromosome 1 regions (previously associated with MMR-related febrile seizures), associated with vaccine-induced measles neutralizing antibody titers. The 1q32 region contained 20 significant SNPs in/around the measles virus receptor-encoding CD46 gene, including the intronic rs2724384 (p value = 2.64 × 10-09) and rs2724374 (p value = 3.16 × 10-09) SNPs. The 1q31.1 region contained nine significant SNPs in/around IFI44L, including the intronic rs1333973 (p value = 1.41 × 10-10) and the missense rs273259 (His73Arg, p value = 2.87 × 10-10) SNPs. Analysis of differential exon usage with mRNA-Seq data and RT-PCR suggests the involvement of rs2724374 minor G allele in the CD46 STP region exon B skipping, resulting in shorter CD46 isoforms. Our study reveals common CD46 and IFI44L SNPs associated with measles-specific humoral immunity, and highlights the importance of alternative splicing/virus cellular receptor isoform usage as a mechanism explaining inter-individual variation in immune response after live measles vaccine.

Impact of atrial fibrillation on platelet gene expression.

AIMS: Platelets retain cytoplasmic messenger RNA and are capable of protein biosynthesis. Several diseases are known to impact the platelet transcriptome but the effect of non-valvular atrial fibrillation (NVAF) on platelet RNA transcript is essentially unknown. The aim of this study was to evaluate the impact of NVAF on platelet RNA transcript by measuring platelet genes expression in consecutive NVAF patients before and 3-4 months after pulmonary vein isolation (PVI) and compared to normal sinus rhythm controls (NSR). METHODS AND RESULTS: RNA from isolated platelets were reverse transcribed, assayed against 15 genes using real-time qPCR, and expressed as mean cycle threshold (ΔCt) using beta-2-microglobulin as endogenous control. Expression of all evaluated genes, except cathepsin A gene, was significantly lower (higher ΔCt) in 103 NVAF patients compared to 55 NSR controls. Insulin-like growth factor binding protein acid labile subunit gene (IGFALS) had expression more than 16 fold-lower (17.0±2.8 vs 12.5±3.8, P<.001), follow by genes encoding for prostacyclin receptor, and for von Willebrand factor which had fourfold lower expression compared to NSR controls. Gender, type of atrial fibrillation, heart failure, hypertension, prior stroke, diabetes mellitus, and atherosclerosis were associated with different gene expression. Following PVI, expression of four genes significantly increased, particularly IGFALS gene (increased 256-fold) and ADAMT gene increased 16-fold); expression of three genes significantly decreased, and expression of eight genes has not changed. CONCLUSIONS: Platelets are capable to respond to the circulatory environment of NVAF by altering transcript and changing prothrombotic status. This shows platelet potential for molecular "reprogramming" possibly induced by flow disturbances of NVAF.

The composition of immune cells serves as a predictor of adaptive immunity in a cohort of 50- to 74-year-old adults.

Influenza causes significant morbidity and mortality annually. Although vaccination offers a considerable amount of protection, it is far from perfect, especially in aging populations. This is due to age-related defects in immune function, a process called immunosenescence. To date, there are no assays or methods to predict or explain variations in an individual's level of response to influenza vaccination. In this study, we measured levels of several immune cell subsets at baseline (Day 0) and at Days 3 and 28 post-vaccination using flow cytometry. Statistical modelling was performed to assess correlations between levels of cell subsets and Day 28 immune responses - haemagglutination inhibition (HAI) assay, virus neutralizing antibody (VNA) assay, and memory B cell ELISPOT. Changes in several groups of cell types from Day 0 to Day 28 and Day 3 to Day 28 were found to be significantly associated with immune response. Baseline levels of several immune cell subsets, including B cells and regulatory T cells, were able to partially explain variation in memory B-cell ELISPOT results. Increased expression of HLA-DR on plasmacytoid dendritic cells after vaccination was correlated with increased HAI and VNA responses. Our data suggest that the expression of activation markers (HLA-DR and CD86) on various immune cell subsets, as well as the relative distribution of cell subsets, both have value in predicting immune responses to influenza vaccination in older individuals.

Prognostic Value of Serial Measurements of Soluble Suppression of Tumorigenicity 2 and Galectin-3 in Ambulatory Patients With Chronic Heart Failure.

BACKGROUND: B-Type natriuretic peptides (BNP) and cardiac troponin T (cTnT) predict cardiovascular events in heart failure (HF) patients, but additional refinement in risk stratification may be possible by targeting pathways leading to fibrosis. We aimed to assess the value of serial measurements of soluble suppression of tumorigenicity 2 (sST2) and galectin-3 to identify risk for adverse pathophysiologic processes. METHODS: New York Heart Association (NYHA) functional class III-IV HF patients (n = 180; LVEF ≤40%) were prospectively evaluated with biomarkers collected every 3 months over 2 years and analyzed regarding a primary end point of death/cardiac transplantation and a secondary end point of HF-related hospitalization or death/transplantation. RESULTS: Time-dependent univariate analyses demonstrated that elevations of sST2 (≥49.3 ng/mL male, ≥33.5 ng/mL female) and galectin-3 (≥22.1 ng/mL) were predictive of the primary and secondary end points. In multivariate models adjusted for BNP, cTnT, and clinical variables, sST2 but not galectin-3 remained an independent predictor (hazard ratio 3.22, 95% confidence interval 1.76-5.89; P < .001). With serial measurements, only sST2 demonstrated incremental value in reclassifying patients to higher risk. CONCLUSIONS: Serial monitoring of sST2 (indicating myocardial fibrosis and remodeling) and cTnT (reflecting myocardial injury) identifies highest-risk HF outpatients and may be valuable to guide patient tailored therapy during follow-up evaluations. Serial galectin-3 monitoring in ambulatory HF patients may not be of benefit.

Relationship between body mass index and left atrial appendage thrombus in nonvalvular atrial fibrillation.

Atrial fibrillation and obesity are two major growing epidemics in the United States and globally. Obese people are at the increased risk of developing atrial fibrillation. The contribution of obesity as an independent risk factor for stroke in the setting of atrial fibrillation remains unclear. We tested the hypothesis that non-valvular atrial fibrillation (NVAF) patients with increased body mass index (BMI) would be at increased risk for the development of left atrial appendage thrombus (LAAT). Consecutive, anticoagulation naïve patients with NVAF referred for a transesophageal echocardiogram (TEE) between January 1, 2007 and October 21, 2009 were approached for study participation. All clinical, laboratory, and TEE measurement data were collected prospectively. Within a group of 400 anticoagulation naïve NVAF patients (mean age 63 ± 15 years, 28 % women; 17 % with LAAT) the prevalence of LAAT was similar across all BMI categories (normal 13 %, overweight 19 %, obese 16 %, morbidly obese 16 %; p = 0.71). Despite a higher CHADS2 score and a higher prevalence of both hypertension and diabetes mellitus, elevated BMI was not an independent predictor of LAAT when analyzed as either a continuous variable, across BMI WHO categories, a dichotomous variable stratified at values above versus below 27 kg/m(2), or BMI stratified on atrial fibrillation duration. Despite a higher prevalence of major risk factors for thromboembolism, the prevalence of LAAT was not increased in overweight, obese, and morbidly obese patients.

Local verification and assignment of mean normal prothrombin time and International Sensitivity Index values across various instruments: recent experience and outcome from North America.

Warfarin dosing relies on accurate measurements of international normalized ratio (INR), which is calculated from the prothrombin time (PT), International Sensitivity Index international sensitivity index (ISI) of the thromboplastin, and the geometric mean of normal PT (MNPT). However, ISI assignments of certain reagent/instrument combinations are frequently unavailable, especially when the reagent and instrument are not from the same manufacturer. The effort to be in compliance with widely endorsed Clinical and Laboratory Standards Institute (CLSI) guidelines by locally verifying or assigning an ISI to an unsupported reagent/instrument combination is further hindered by the lack of US Food and Drug Administration (FDA)-approved certified plasmas designated for a particular reagent/instrument combination. The objectives of the study include development of a process to verify/assign ISI and MNPT of a single thromboplastin reagent from one manufacturer across multiple instruments including several from another manufacturer and across several campuses of a single institution, the Mayo Clinic. In this study, RecombiPlasTin 2G (R2G), was evaluated on the ACL TOP 700 (IL), STA-R Evolution, STA Compact, and STA Satellite. Random normal donor samples (n = 25) were used to verify/assign MNPT. A subset of the normal donors (n = 8) and 13 warfarin pools (INR range: 1.3-3.9), created from stable warfarin patient plasma, were used for ISI verification/assignment. The manufacturer's assigned ISI was first verified on the ACL TOP 700 (reference method), then assigned on three unsupported instruments using orthogonal regression analysis. The MNPT and manufacturer assigned ISI (11.0, 0.95) were verified on the ACL TOP 700 and subsequently assigned on the STA-R Evolution (11.6, 1.04); STA Compact (11.5, 1.02); and STA Satellite (10.9, 0.99). Linear correlations of the INR results from all the four instruments demonstrated an r2 > 0.99. This process provides a reproducible approach to assigning ISIs on unsupported reagent/instrument combinations. Our data also confirm that ISIs of the same PT reagent differ significantly on different instruments, thus confirming the requirement for evaluations and validation of ISIs for different reagent/instrument combinations.

Comparison of Blood Volume Profiles in Heart Failure With Preserved and Reduced Ejection Fractions: Sex Makes a Difference.

BACKGROUND: Blood volume (BV) profiles vary markedly in patients with heart failure (HF), but how HF phenotypes and patient sex impact volume profiles remain to be explored. The aim of the study was to differentiate BV, plasma volume, and red blood cell mass profiles by phenotypes of preserved and reduced left ventricular ejection fractions and assess the impact of patient sex on profile heterogeneity. METHODS: Retrospective analysis of clinical and BV data was undertaken in patients with chronic New York Heart Association II-III heart failure. BV was quantitated using the nuclear medicine indicator-dilution methodology. RESULTS: A total of 530 BV analyses (360 HF with reduced ejection fraction and 170 HF with preserved ejection fraction) were identified in 395 unique patients. Absolute BV was greater in HF with reduced ejection fraction (6.7±1.8 versus 5.9±1.6 liters: P<0.001); however, large variability in frequency distribution of volume profiles was observed in both phenotypes (-22% deficit to +109% excess relative to normal volumes). HF with reduced ejection fraction was characterized by a higher prevalence of BV expansion ≥+25% of normal (39% versus 26%; P=0.003), and HF with preserved ejection fraction was characterized a by more frequent normal BV (42% versus 24%; P<0.001). Male sex in both phenotypes was associated with a larger absolute BV (7.0±1.6 versus 5.1±1.3 liters; P<0.001) and higher frequency of large BV and plasma volume expansions above normal (both P<0.001), while females in both phenotypes demonstrated a higher prevalence of normal BV and plasma volume (both P<0.001). CONCLUSIONS: Findings support significant differences in BV, plasma volume, and red blood cell mass profile distributions between heart failure phenotypes, driven in large part by sex-specific factors. This underscores the importance of identifying and distinguishing individual patient volume profiles to help guide volume management strategies.