Cross-Platform Comparison of Highly Sensitive Immunoassays for Inflammatory Markers in a COVID-19 Cohort

A variety of commercial platforms are available for the simultaneous detection of multiple cytokines and associated proteins, often employing Ab pairs to capture and detect target proteins. In this study, we comprehensively evaluated the performance of three distinct platforms: the fluorescent bead-based Luminex assay, the proximity extension-based Olink assay, and a novel proximity ligation assay platform known as Alamar NULISAseq. These assessments were conducted on human serum samples from the National Institutes of Health IMPACC study, with a focus on three essential performance metrics: detectability, correlation, and differential expression. Our results reveal several key findings. First, the Alamar platform demonstrated the highest overall detectability, followed by Olink and then Luminex. Second, the correlation of protein measurements between the Alamar and Olink platforms tended to be stronger than the correlation of either of these platforms with Luminex. Third, we observed that detectability differences across the platforms often translated to differences in differential expression findings, although high detectability did not guarantee the ability to identify meaningful biological differences. Our study provides valuable insights into the comparative performance of these assays, enhancing our understanding of their strengths and limitations when assessing complex biological samples, as exemplified by the sera from this COVID-19 cohort.

Cross-platform comparison of highly-sensitive immunoassays for inflammatory markers in a COVID-19 cohort 1

A variety of commercial platforms are available for the simultaneous detection of multiple cytokines and associated proteins, often employing antibody pairs to capture and detect target proteins. In this study, we comprehensively evaluated the performance of three distinct platforms: the fluorescent bead-based Luminex assay, the proximity extension-based Olink assay, and a novel proximity ligation assay platform known as Alamar NULISAseq. These assessments were conducted on serum samples from the NIH IMPACC study, with a focus on three essential performance metrics: detectability, correlation, and differential expression. Our results reveal several key findings. Firstly, the Alamar platform demonstrated the highest overall detectability, followed by Olink and then Luminex. Secondly, the correlation of protein measurements between the Alamar and Olink platforms tended to be stronger than the correlation of either of these platforms with Luminex. Thirdly, we observed that detectability differences across the platforms often translated to differences in differential expression findings, although high detectability did not guarantee the ability to identify meaningful biological differences. Our study provides valuable insights into the comparative performance of these assays, enhancing our understanding of their strengths and limitations when assessing complex biological samples, as exemplified by the sera from this COVID-19 cohort.

Relationship of Heterologous Virus Responses and Outcomes in Hospitalized COVID-19 Patients

The clinical trajectory of COVID-19 may be influenced by previous responses to heterologous viruses. We examined the relationship of Abs against different viruses to clinical trajectory groups from the National Institutes of Health IMPACC (Immunophenotyping Assessment in a COVID-19 Cohort) study of hospitalized COVID-19 patients. Whereas initial Ab titers to SARS-CoV-2 tended to be higher with increasing severity (excluding fatal disease), those to seasonal coronaviruses trended in the opposite direction. Initial Ab titers to influenza and parainfluenza viruses also tended to be lower with increasing severity. However, no significant relationship was observed for Abs to other viruses, including measles, CMV, EBV, and respiratory syncytial virus. We hypothesize that some individuals may produce lower or less durable Ab responses to respiratory viruses generally (reflected in lower baseline titers in our study), and that this may carry over into poorer outcomes for COVID-19 (despite high initial SARS-CoV-2 titers). We further looked at longitudinal changes in Ab responses to heterologous viruses, but found little change during the course of acute COVID-19 infection. We saw significant trends with age for Ab levels to many of these viruses, but no difference in longitudinal SARS-CoV-2 titers for those with high versus low seasonal coronavirus titers. We detected no difference in longitudinal SARS-CoV-2 titers for CMV seropositive versus seronegative patients, although there was an overrepresentation of CMV seropositives among the IMPACC cohort, compared with expected frequencies in the United States population. Our results both reinforce findings from other studies and suggest (to our knowledge) new relationships between the response to SARS-CoV-2 and Abs to heterologous viruses.

Acute Respiratory Illness Is Associated with Memory T Cell Differentiation and Other Immune Cell Changes in an Age-Associated Manner

Respiratory viruses such as influenza are encountered multiple times through infection and/or vaccination and thus have the potential to shape immune cell phenotypes over time. In particular, memory T cell compartments may be affected, as both CD4+ and CD8+ T cell responses likely contribute to viral control. In this study, we assessed immune phenotypes using cytometry by time of flight in the peripheral blood of 22 humans with acute respiratory illness and 22 age-matched noninfected controls. In younger infected individuals (1-19 y of age), we found decreased B and NK cell frequencies and a shift toward more effector-like CD4+ and CD8+ T cell phenotypes, compared with young healthy controls. Significant differences between noninfected and infected older individuals (30-74 y of age) were not seen. We also observed a decrease in naive CD4+ T cells and CD27+CD8+ T cells as well as an increase in effector memory CD8+ T cells and NKT cells in noninfected individuals with age. When cell frequencies were regressed against age for infected versus noninfected subjects, significant differences in trends with age were observed for multiple cell types. These included B cells and various subsets of CD4+ and CD8+ T cells. We conclude that acute respiratory illness drives T cell differentiation and decreases circulating B cell frequencies preferentially in young compared with older individuals.

A taxonomy of multiple regression methods for immunologists

Multiple regression is a powerful tool in the immunologist's toolbox. This paper defines multiple regression, discusses availability and accessibility, provides some additional helpful definitions, treats the topics of transformation and extreme value screening, and establishes the paper's scope and philosophy. Then eleven methods of multiple regression are detailed, giving strengths and limitations. Throughout an emphasis is placed on application to immunological assays. A flowchart to guide selection of multiple regression methods is provided.

Epigenetic and immunological indicators of IPEX disease in subjects with FOXP3 gene mutation

BACKGROUND

Forkhead box protein 3 (FOXP3) is the master transcription factor in CD4⁺CD25^hiCD127^lo regulatory T (Treg) cells. Mutations in FOXP3 result in IPEX (immune dysregulation, polyendocrinopathy, enteropathy, X-linked) syndrome. Clinical presentation of IPEX syndrome is broader than initially described, challenging the understanding of the disease, its evolution, and treatment choice.

OBJECTIVE

We sought to study the type and extent of immunologic abnormalities that remain ill-defined in IPEX, across genetic and clinical heterogeneity.

METHODS

We performed Treg-cell-specific epigenetic quantification and immunologic characterization of severe "typical" (n = 6) and "atypical" or asymptomatic (n = 9) patients with IPEX.

RESULTS

Increased number of cells with Treg-cell-Specific Demethylated Region demethylation in FOXP3 is a consistent feature in patients with IPEX, with (1) highest values in those with typical IPEX, (2) increased values in subjects with pathogenic FOXP3 but still no symptoms, and (3) gradual increase over the course of disease progression. Large-scale profiling using Luminex identified plasma inflammatory signature of macrophage activation and T_H2 polarization, with cytokines previously not associated with IPEX pathology, including CCL22, CCL17, CCL15, and IL-13, and the inflammatory markers TNF-α, IL-1A, IL-8, sFasL, and CXCL9. Similarly, both Treg-cell and Teff compartments, studied by Mass Cytometry by Time-Of-Flight, were skewed toward the T_H2 compartment, especially in typical IPEX.

CONCLUSIONS

Elevated TSDR-demethylated cells, combined with elevation of plasmatic and cellular markers of a polarized type 2 inflammatory immune response, extends our understanding of IPEX diagnosis and heterogeneity.

Rigorous quantification of bacterial richness in ticks: A case study

Kwan et al. (2017) published an informative study comparing results obtained by next-generation sequencing (NGS) of mean bacterial genera richness among different life stages, male and female adults, and rearing conditions (field vs. laboratory) for Ixodes pacificus. The current paper examines Kwan et al. (2017) as a case study to provide guidance on statistical design and analysis for estimation of richness, derived from next generation sequencing technology, of the bacterial microbiome in field-collected I. pacificus. Suggestions are provided to further strengthen quantification of microbiome richness in studies in ticks, with focus on sampling design. In-depth treatment is provided of the relative merits of estimating mean richness versus median richness. Research on microbiome diversity in ticks can be made quantitatively rigorous; although, more research on methods is needed.

Mass Cytometry Defines Virus-Specific CD4+ T Cells in Influenza Vaccination

The antiviral response to influenza virus is complex and multifaceted, involving many immune cell subsets. There is an urgent need to understand the role of CD4⁺ T cells, which orchestrate an effective antiviral response, to improve vaccine design strategies. In this study, we analyzed PBMCs from human participants immunized with influenza vaccine, using high-dimensional single-cell proteomic immune profiling by mass cytometry. Data were analyzed using a novel clustering algorithm, denoised ragged pruning, to define possible influenza virus–specific clusters of CD4⁺ T cells. Denoised ragged pruning identified six clusters of cells. Among these, one cluster (Cluster 3) was found to increase in abundance following stimulation with influenza virus peptide ex vivo. A separate cluster (Cluster 4) was found to expand in abundance between days 0 and 7 postvaccination, indicating that it is vaccine responsive. We examined the expression profiles of all six clusters to characterize their lineage, functionality, and possible role in the response to influenza vaccine. Clusters 3 and 4 consisted of effector memory cells, with high CD154 expression. Cluster 3 expressed cytokines like IL-2, IFN-γ, and TNF-α, whereas Cluster 4 expressed IL-17. Interestingly, some participants had low abundance of Clusters 3 and 4, whereas others had higher abundance of one of these clusters compared with the other. Taken together, we present an approach for identifying novel influenza virus–reactive CD4⁺ T cell subsets, a method that could help advance understanding of the immune response to influenza, predict responsiveness to vaccines, and aid in better vaccine design.

Generalized mathematical model for immunoassay interference

As part of a landmark review of the antigen excess, Jacobs et al. (Autoimmunity Reviews 2015;14:160-167) contrast how immunoassay "interference" by non-target biomolecules can cause spurious readings for clinical diagnostic tests. The purpose of the present Letter is to complement and analytically extend this description by Jacobs et al. by briefly presenting a generalized mathematical model of immunoassay interference that is derived from a simple mechanistic system of differential equations. Derivation includes expressions for the location of the peak concentration of bound reporter as well as that maximum concentration of target biomolecule at which immunoassay interference drives concentration of bound reporter to zero. This parsimonious, mechanistic, and generalized model may prove foundational to analytic study of immunoassay interference. More comprehensive models for specific classes of immunoassays have and can be developed.

Genetic Characterization of Toxoplasma gondii DNA Samples Isolated From Humans Living in North America: An Unexpected High Prevalence of Atypical Genotypes

Background

Whereas in Europe most of Toxoplasma gondii genotypes belong to the type II lineage, in Latin America, type II is rare and atypical strains predominate. In North America, data on T. gondii genotypes in humans are scarce.

Methods

In this study, T. gondii DNA samples from 67 patients with diagnosed toxoplasmosis in the United States were available for genotyping. Discriminant analysis of principal components was used to infer each atypical genotype to a geographic area where patients were probably infected. Associations between genotype, disease severity, immune status, and geographic region were also estimated.

Results

Of 67 DNA samples, 41 were successfully genotyped: 18 (43.9%) and 5 (12.2%) were characterized as types II and III, respectively. The remaining 18 genotypes (43.9%) were atypical and were assigned to a geographic area. Ten genotypes originated from Latin America, 7 from North America, and 1 from Asia (China). In North America, unlike in Europe, T. gondii atypical genotypes are common in humans and, unlike in Latin America, type II strains are still present with significant frequency.

Conclusions

Clinicians should be aware that atypical genotypes are common in North America and have been associated with severe ocular and systemic disease and unusual presentations of toxoplasmosis in immunocompetent patients.

Diminished B-Cell Response After Repeat Influenza Vaccination

Annual vaccination with influenza vaccines is recommended for protection against influenza in the United States. Past clinical studies and meta-analysis, however, have reported conflicting results on the benefits of annual vaccination. B-cell responses elicited following repeat influenza vaccinations over multiple seasons have not been examined in detail. We analyzed the B-cell and antibody (Ab) responses in volunteers vaccinated yearly, from 2010 or 2011 through 2014, with seasonal trivalent inactivated influenza vaccines. Statistical analyses were designed to help correct for possible bias due to reduced sample size in the later years of the study. We show that, after the second annual vaccination, the frequency of vaccine-specific plasmablasts and the binding reactivity of plasmablast-derived polyclonal Abs are reduced and do not increase in subsequent years. Similar trends are observed with the serum hemagglutination inhibition Ab response after each annual vaccination, as well as the binding reactivity of plasmablast-derived polyclonal Abs to the hemagglutinin of influenza A virus vaccine components, even with changes in the seasonal vaccine components during the study. Our findings indicate a diminished B-cell response to annual vaccination with seasonal trivalent influenza vaccine. These results emphasize the need for developing improved strategies to enhance the immunogenicity and efficacy of annual influenza vaccination.

Penalized Supervised Star Plots: Example Application in Influenza-Specific CD4+ T Cells

An immune cell's phenotype expresses through its high-dimensional marker signature. Cluster analyses of data from high-throughput mass and flow cytometry marker panels permit discovery of previously undescribed immune cell phenotypes. Impactful reporting of new phenotypes demands low-dimensional visualization tools that preserve with integrity phenotypes' original high-dimensional structure. For this purpose, we introduce penalized supervised star plots. As designed and as we demonstrate, penalized supervised star plots are two-dimensional projections that tend to preserve separation of clusters as well as information on the relative contributions of various markers in differentiating phenotypes. The new method is robust to markers that do not differentiate phenotypes at all, as shown in a challenge data set. Results include comparison with other popular procedures. Penalized supervised star plots incorporate cross-validation to permit portability of estimated optimal projections to new samples. Supervised star plots are further illustrated with a featured influenza-specific T cell data set as well as a peripheral blood mononuclear cell phenotyping data set.

Differences in multiple immune parameters between Indian and U.S. infants

To compare immune phenotypes across two geographic and ethnic communities, we examined umbilical cord blood by flow cytometry and Luminex in parallel cohorts of 53 newborns from New Delhi, India, and 46 newborns from Stanford, California. We found that frequencies of a B cell subset suggested to be B-1-like, and serum IgM concentration were both significantly higher in the Stanford cohort, independent of differences in maternal age. While serum IgA levels were also significantly higher in the Stanford cohort, IgG1, IgG2, and IgG4 were significantly higher in the New Delhi samples. We found that neutrophils, plasmacytoid dendritic cells, CD8+ T cells, and total T cells were higher in the U.S. cohort, while dendritic cells, patrolling monocytes (CD14dimCD16+), natural killer cells, CD4+ T cells, and naïve B cells were higher in the India cohort. Within the India cohort, we also identified cell types whose frequency was positively or negatively predictive of occurrence of infection(s) in the first six months of life. Monocytes, total T cells, and memory CD4+ T cells were most prominent in having an inverse relationship with infection. We suggest that these data provide impetus for follow-up studies linking phenotypic differences to environmental versus genetic factors, and to infection outcomes.

Linear-rank testing of a non-binary, responder-analysis, efficacy score to evaluate pharmacotherapies for substance use disorders

The design of pharmacological trials for management of substance use disorders is shifting toward outcomes of successful individual-level behavior (abstinence or no heavy use). While binary success/failure analyses are common, McCann and Li (CNS Neurosci Ther 2012; 18: 414-418) introduced "number of beyond-threshold weeks of success" (NOBWOS) scores to avoid dichotomized outcomes. NOBWOS scoring employs an efficacy "hurdle" with values reflecting duration of success. Here, we evaluate NOBWOS scores rigorously. Formal analysis of mathematical structure of NOBWOS scores is followed by simulation studies spanning diverse conditions to assess operating characteristics of five linear-rank tests on NOBWOS scores. Simulations include assessment of Fisher's exact test applied to hurdle component. On average, statistical power was approximately equal for five linear-rank tests. Under none of conditions examined did Fisher's exact test exhibit greater statistical power than any of the linear-rank tests. These linear-rank tests provide good Type I and Type II error control for comparing distributions of NOBWOS scores between groups (e.g. active vs. placebo). All methods were applied to re-analyses of data from four clinical trials of differing lengths and substances of abuse. These linear-rank tests agreed across all trials in rejecting (or not) their null (equality of distributions) at ≤ 0.05.

Canine companionship is associated with modification of attentional bias in posttraumatic stress disorder

Attentional bias towards aversive stimuli has been demonstrated in the anxiety disorders and in posttraumatic stress disorder, and attentional bias modification has been proposed as a candidate treatment. This study rigorously assessed attentional bias towards aversive and pleasant visual imagery associated with the presence or absence of a familiar service canine in 23 veterans with chronic military-related posttraumatic stress disorder. Participants were repeatedly tested with and without their service canines present on two tasks designed to elicit spontaneous visual attention to facial and scenic image pairs, respectively. Each stimulus contrasted an emotive image with a neutral image. Via eye-tracking, the difference in visual attention directed to each image was analyzed as a function of the valence contrast and presence/absence of the canine. Across both tasks, the presence of a familiar service canine attenuated the normative attentional bias towards aversive image content. In the facial task, presence of the service canine specifically reduced attention toward angry faces. In that task, as well, accumulated days with the service canine similarly modulated attention toward facial emotion. The results suggest that the presence of a familiar service canine is associated with attenuation of attentional bias to aversive stimuli in chronic military-service-related posttraumatic stress disorder. Questions remain regarding the generalization of such effects to other populations, their dependence on the familiarity, breed, and training of the canine, and on social context.

Adherence to continuous positive airway pressure improves attention/psychomotor function and sleepiness: a bias-reduction method with further assessment of APPLES

OBJECTIVE/BACKGROUND

Variable adherence to prescribed therapies for sleep disorders is commonplace. This study was designed to integrate three available statistical technologies (instrumental variables, residual inclusion, and shrinkage) to allow sleep investigators to employ data on variable adherence in the estimation of the causal effect of treatment as received on clinical outcomes.

PATIENTS/METHODS

Using data from the Apnea Positive Pressure Long-term Efficacy Study (APPLES), regression adjustment for observed and unobserved confounders was applied to two primary neurocognitive outcomes, plus two measures of sleepiness. We demonstrate how to obtain estimates of reduced uncertainty for the causal effect of treatment as received for continuous positive airway pressure (CPAP) within clinical subpopulations (defined by baseline disease severity) of sleep apnea patients.

RESULTS AND CONCLUSIONS

Following six months of treatment, statistically significant improvements caused by device adherence were detected for subjective sleepiness in mild, moderate, and severe disease, objective sleepiness in severe disease, and attention and psychomotor function in moderate disease. Some evidence for worsening of learning and memory due to increased adherence in moderate disease was also detected. Application to APPLES illustrates that this method can yield bias corrections for unobserved confounders that are substantial-revealing new clinical findings. Use of this fully general method throughout sleep research could sharpen understanding of the true efficacy of pharmacotherapies, medical devices, and behavioral interventions. Extensive technical appendices are provided to facilitate application of this general method. Clinicaltrials.gov identifier NCT00051363.

Effect of an Intensive Outpatient Program to Augment Primary Care for High-Need Veterans Affairs Patients: A Randomized Clinical Trial

IMPORTANCE

Many organizations are adopting intensive outpatient care programs for high-need patients, yet little is known about their effectiveness in integrated systems with established patient-centered medical homes.

OBJECTIVE

To evaluate how augmenting the Veterans Affairs (VA) medical home (Patient Aligned Care Teams [PACT]) with an Intensive Management program (ImPACT) influences high-need patients' costs, health care utilization, and experience.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial at a single VA facility. Among 583 eligible high-need outpatients whose health care costs or hospitalization risk were in the top 5% for the facility, 150 were randomly selected for ImPACT; the remaining 433 received standard PACT care.

INTERVENTIONS

The ImPACT multidisciplinary team addressed health care needs and quality of life through comprehensive patient assessments, intensive case management, care coordination, and social and recreational services.

MAIN OUTCOMES AND MEASURES

Primary difference-in-difference analyses examined changes in health care costs and acute and extended care utilization over a 16-month baseline and 17-month follow-up period. Secondary analyses estimated the intervention's effect on ImPACT participants (using randomization as an instrument) and for patients with key sociodemographic and clinical characteristics. ImPACT participants' satisfaction and activation levels were assessed using responses to quality improvement surveys administered at baseline and 6 months.

RESULTS

Of 140 patients assigned to ImPACT, 96 (69%) engaged in the program (mean [SD] age, 68.3 [14.2] years; 89 [93%] male; mean [SD] number of chronic conditions, 10 [4]; 62 [65%] had a mental health diagnosis; 21 [22%] had a history of homelessness). After accounting for program costs, adjusted person-level monthly health care expenditures decreased similarly for ImPACT and PACT patients (difference-in-difference [SE] -$101 [$623]), as did acute and extended care utilization rates. Among respondents to the ImPACT follow-up survey (n = 54 [56% response rate]), 52 (96%) reported that they would recommend the program to others, and pre-post analyses revealed modest increases in satisfaction with VA care (mean [SD] increased from 2.90 [0.72] to 3.16 [0.60]; P = .04) and communication (mean [SD] increased from 2.99 [0.74] to 3.18 [0.60]; P = .03).

CONCLUSIONS AND RELEVANCE

Intensive outpatient care for high-need patients did not reduce acute care utilization or costs compared with standard VA care, although there were positive effects on experience among patients who participated. Implementing intensive outpatient care programs in integrated settings with well-established medical homes may not prevent hospitalizations or achieve substantial cost savings.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02932228.

Cytokine profiles in patients with toxoplasmic lymphadenitis in the setting of pregnancy

INTRODUCTION

Majority of Toxoplasma gondii infections are benign and asymptomatic; however, some patients experience toxoplasmic lymphadenitis (TL). Factors associated as to whether infection will be symptomatic or not are unknown.

METHODS

Dye test titers of patients with acute toxoplasmosis (pregnant and not pregnant) with TL (TL+) were compared with those in patients with asymptomatic acute infection (TL-). Additionally, mean levels of 62 serum cytokines were compared between TL+ and TL- pregnant women and between TL+ pregnant and non-pregnant women.

RESULTS

During acute infection, mean dye test titer was higher in TL+ than in TL- patients (p=0.021). In addition, out of 62 cytokines, CXCL9andCXCL10 levels were higher (p<0.05) and resistin mean levels were lower (p<0.05) in pregnant women with TL+ compared to TL-. Among patients with TL+, levels of VCAM1andCCL2 were lower (p<0.05) in pregnant women than in non-pregnant women.

CONCLUSION

Here we report differences in dye test titers in patients with acute infection. Cytokine responses vary according to the presence of TL+ and to the pregnancy status. Factors underlying these differences are presently unknown and require further studies to define individual and combined roles of cytokines in TL+.

Human immunophenotyping via low-variance, low-bias, interpretive regression modeling of small, wide data sets: Application to aging and immune response to influenza vaccination

Small, wide data sets are commonplace in human immunophenotyping research. As defined here, a small, wide data set is constructed by sampling a small to modest quantity n,1 Collapse

Key Words

• Confidence interval
• Denoising
• Influenza
• Statistical assumptions
• Statistical bias
• Statistical regression modeling

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MESH Headings

• Adult
• Aging/immunology
• Analysis of Variance
• Antibodies, Viral/blood
• B-Lymphocytes/immunology
• Bias
• Cytokines/metabolism
• Datasets as Topic
• Humans
• Immunoglobulin A/blood
• Immunoglobulin G/blood
• Influenza Vaccines/immunology
• Influenza, Human/diagnosis
• Influenza, Human/epidemiology
• Influenza, Human/immunology
• Models, Theoretical
• Monitoring, Immunologic/methods
• Prognosis
• Regression Analysis

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Grants

• U19 AI057229 NIAID NIH HHS
• UL1 TR001085 NCATS NIH HHS

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Affiliation(s)

Tyson H Holmes Stanford University Human Immune Monitoring Center, Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Stanford, CA 94305, USA.
Xiao-Song He Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, USA; VA Palo Alto Healthcare System, 3801 Miranda Avenue, Palo Alto, CA 94304, USA.

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Longitudinal Kinetics of Cytomegalovirus-Specific T-Cell Immunity and Viral Replication in Infants With Congenital Cytomegalovirus Infection

BACKGROUND

Congenital cytomegalovirus (CMV) is reported to affect up to 1% of all live births in the United States. T-cell immunity may be important for controlling CMV replication in congenital CMV-infected infants. We describe the natural history of CMV-specific T-cell evolution and CMV replication in infants with congenital CMV infection.

METHODS

Cytomegalovirus viral load, CMV urine culture, and CMV-specific CD4 and CD8 T-cell responses were assessed in a prospective longitudinal cohort of 51 infants with congenital CMV infection who were observed from birth to 3 years of age.

RESULTS

We found a kinetic pattern of decreasing urinary CMV replication and increasing CMV-specific CD4 and CD8 T-cell responses during the first 3 years of life. We also found higher CMV-specific CD8 T-cell responses were associated with subsequent reduction of urine CMV viral load.

CONCLUSION

For infants with congenital CMV infection, our data suggest an age-related maturation of both CMV-specific CD4 and CD8 T-cell immunity that is associated with an age-related decline in urinary CMV replication.

Dopamine D3 Receptor Antagonist (GSK598809) Potentiates the Hypertensive Effects of Cocaine in Conscious, Freely-Moving Dogs

The chronic and relapsing nature of addiction presents unique challenges for ensuring the safety of a potential medication. A patient may use cocaine, for example, while taking the medication or take more medication than prescribed. Thus, a potential medication must be safe and not exacerbate the effects of cocaine. Multiple published studies support antagonism of brain dopamine D3 receptor function as a potential mechanism of action for an anti-addiction medication. Dopamine D3 receptors are widely distributed outside the central nervous system, however; for example, dopamine D3 receptors in the kidneys are implicated in regulating blood pressure. The selective dopamine D3 receptor antagonist GSK598809 [1-(2-fluoro-4-trifluoromethyl-phenyl)-3-{3-[4-methyl-5-(4-methyl-oxazol-5-yl)-4H-[1,2,4]triazol-3-ylsulfanyl]-propyl}-3-aza-bicyclo[3.1.0]hexane] has been proposed as a medication to treat cocaine and other substance use disorders. The US Food and Drug Administration has established guidelines recommending safety studies to investigate potential undesirable pharmacodynamic effects of a substance in relation to exposure in the therapeutic range and above. Hence, we assessed the interaction between this selective dopamine D3 receptor antagonist and cocaine on hemodynamics and cardiac function in freely-moving, telemetered dogs before conducting a clinical trial. GSK598809 increased the hemodynamic effect of cocaine in this model. Thus, the increase in blood pressure after intravenous cocaine was greater in animals that had been pretreated with GSK598809 compared with vehicle. This finding suggests that GSK598809 in particular, and perhaps dopamine D3 receptor antagonists as a class, may produce unacceptable cardiovascular risks as medications to treat cocaine use disorder.

Abnormalities of lipoprotein concentrations in obstructive sleep apnea are related to insulin resistance

STUDY OBJECTIVE

Prevalence of cardiovascular disease (CVD) is increased in patients with obstructive sleep apnea (OSA), possibly related to dyslipidemia in these individuals. Insulin resistance is also common in OSA, but its contribution to dyslipidemia of OSA is unclear. The study's aim was to define the relationships among abnormalities of lipoprotein metabolism, clinical measures of OSA, and insulin resistance.

DESIGN

Cross-sectional study. OSA severity was defined by the apnea-hypopnea index (AHI) during polysomnography. Hypoxia measures were expressed as minimum and mean oxygen saturation, and the oxygen desaturation index. Insulin resistance was quantified by determining steady-state plasma glucose (SSPG) concentrations during the insulin suppression test. Fasting plasma lipid/lipoprotein evaluation was performed by vertical auto profile methodology.

SETTING

Academic medical center.

PARTICIPANTS

107 nondiabetic, overweight/obese adults.

MEASUREMENTS AND RESULTS

Lipoprotein particles did not correlate with AHI or any hypoxia measures, nor were there differences noted by categories of OSA severity. By contrast, even after adjustment for age, sex, and BMI, SSPG was positively correlated with triglycerides (r = 0.30, P < 0.01), very low density lipoprotein (VLDL) and its subclasses (VLDL1+2) (r = 0.21-0.23, P < 0.05), and low density lipoprotein subclass 4 (LDL4) (r = 0.30, P < 0.01). SSPG was negatively correlated with high density lipoprotein (HDL) (r = -0.38, P < 0.001) and its subclasses (HDL2 and HDL3) (r = -0.32, -0.43, P < 0.01), and apolipoprotein A1 (r = -0.33, P < 0.01). Linear trends of these lipoprotein concentrations across SSPG tertiles were also significant.

CONCLUSIONS

Pro-atherogenic lipoprotein abnormalities in obstructive sleep apnea (OSA) are related to insulin resistance, but not to OSA severity or degree of hypoxia. Insulin resistance may represent the link between OSA-related dyslipidemia and increased cardiovascular disease risk.

Bupropion for the treatment of methamphetamine dependence in non-daily users: a randomized, double-blind, placebo-controlled trial

AIM

Bupropion was tested for efficacy to achieve methamphetamine (MA) abstinence in dependent, non-daily users.

METHODS

A randomized, double-blind, placebo-controlled trial, with 12-week treatment and 4-week follow-up, was conducted with 204 treatment-seeking participants having MA dependence per DSM-IV, who used MA on a less-than-daily basis. 104 were randomized to matched placebo and 100 to bupropion, sustained-release 150mg, twice daily. Participants were seen three times weekly to obtain urine for MA and bupropion assays, study assessments, and thrice weekly, 90-min, group psychotherapy. There was no biomarker for placebo adherence. The primary outcome was achievement of abstinence throughout the last two weeks of treatment; 'success' requiring at least two urine samples during each of Weeks 11 and 12, and all samples MA-negative (<300ng/mL).

RESULTS

Bupropion and placebo groups did not differ significantly in the percentage achieving abstinence for the last 2 weeks of treatment (chi-square, p=0.32). Subgroup analysis of participants with lower baseline MA use (≤18 of last 30 days before consent) also revealed no difference in success between groups (p=0.73). Medication adherence per protocol (detectable bupropion, >5ng/mL, in ≥50% of urine samples from Study Weeks 1-10 and ≥66% of urine samples from Weeks 11 to 12) was achieved by 47% of participants taking bupropion.

CONCLUSIONS

These data indicate that bupropion did not increase abstinence in dependent participants who were using MA less-than-daily. Medication non-adherence was a limitation in this trial. Psychosocial therapy remains the mainstay of treatment for MA dependence. Further research on subgroups who may respond to bupropion may be warranted.

Multimorbidity and healthcare utilisation among high-cost patients in the US Veterans Affairs Health Care System

OBJECTIVES

To investigate the relationship between multimorbidity and healthcare utilisation patterns among the highest cost patients in a large, integrated healthcare system.

DESIGN

In this retrospective cross-sectional study of all patients in the U.S. Veterans Affairs (VA) Health Care System, we aggregated costs of individuals' outpatient and inpatient care, pharmacy services and VA-sponsored contract care received in 2010. We assessed chronic condition prevalence, multimorbidity as measured by comorbidity count, and multisystem multimorbidity (number of body systems affected by chronic conditions) among the 5% highest cost patients. Using multivariate regression, we examined the association between multimorbidity and healthcare utilisation and costs, adjusting for age, sex, race/ethnicity, marital status, homelessness and health insurance status.

SETTING

USA VA Health Care System.

PARTICIPANTS

5.2 million VA patients.

MEASURES

Annual total costs; absolute and share of costs generated through outpatient, inpatient, pharmacy and VA-sponsored contract care; number of visits to primary, specialty and mental healthcare; number of emergency department visits and hospitalisations.

RESULTS

The 5% highest cost patients (n=261,699) accounted for 47% of total VA costs. Approximately two-thirds of these patients had chronic conditions affecting ≥3 body systems. Patients with cancer and schizophrenia were less likely to have documented comorbid conditions than other high-cost patients. Multimorbidity was generally associated with greater outpatient and inpatient utilisation. However, increased multisystem multimorbidity was associated with a higher outpatient share of total costs (1.6 percentage points per affected body system, p<0.01) but a lower inpatient share of total costs (-0.6 percentage points per affected body system, p<0.01).

CONCLUSIONS

Multisystem multimorbidity is common among high-cost VA patients. While some patients might benefit from disease-specific programmes, for most patients with multimorbidity there is a need for interventions that coordinate and maximise efficiency of outpatient services across multiple conditions.

SMART DOCS: a new patient-centered outcomes and coordinated-care management approach for the future practice of sleep medicine

ABSTRACT

The practice of medicine is currently undergoing a transformation to become more efficient, cost-effective, and patient centered in its delivery of care. The aim of this article is to stimulate discussion within the sleep medicine community in addressing these needs by our approach as well as other approaches to sleep medicine care. The primary goals of the Sustainable Methods, Algorithms, and Research Tools for Delivering Optimal Care Study (SMART DOCS) are: (1) to introduce a new Patient-Centered Outcomes and Coordinated-Care Management (PCCM) approach for the future practice of sleep medicine, and (2) to test the PCCM approach against a Conventional Diagnostic and Treatment Outpatient Medical Care (CONV) approach in a randomized, two-arm, single-center, long-term, comparative effectiveness trial. The PCCM approach is integrated into a novel outpatient care delivery model for patients with sleep disorders that includes the latest technology, allowing providers to obtain more accurate and rapid diagnoses and to make evidence-based treatment recommendations, while simultaneously enabling patients to have access to personalized medical information and reports regarding their diagnosis and treatment so that they can make more informed health care decisions. Additionally, the PCCM approach facilitates better communication between patients, referring primary care physicians, sleep specialists, and allied health professionals so that providers can better assist patients in achieving their preferred outcomes. A total of 1,506 patients 18 y or older will be randomized to either the PCCM or CONV approach and will be followed for at least 1 y with endpoints of improved health care performance, better health, and cost control.

CLINICAL TRIALS NUMBER

http://www.clinicaltrials.gov, NCT02037438.

Mental illness and intensification of diabetes medications: an observational cohort study

BACKGROUND

Mental health condition (MHC) comorbidity is associated with lower intensity care in multiple clinical scenarios. However, little is known about the effect of MHC upon clinicians' decisions about intensifying antiglycemic medications in diabetic patients with poor glycemic control. We examined whether delay in intensification of antiglycemic medications in response to an elevated Hemoglobin A1c (HbA1c) value is longer for patients with MHC than for those without MHC, and whether any such effect varies by specific MHC type.

METHODS

In this observational study of diabetic Veterans Health Administration (VA) patients on oral antiglycemics with poor glycemic control (HbA1c ≥8) (N =52,526) identified from national VA databases, we applied Cox regression analysis to examine time to intensification of antiglycemics after an elevated HbA1c value in 2003-2004, by MHC status.

RESULTS

Those with MHC were no less likely to receive intensification: adjusted Hazard Ratio [95% CI] 0.99 [0.96-1.03], 1.13 [1.04-1.23], and 1.12 [1.07-1.18] at 0-14, 15-30 and 31-180 days, respectively. However, patients with substance use disorders were less likely than those without substance use disorders to receive intensification in the first two weeks following a high HbA1c, adjusted Hazard Ratio 0.89 [0.81-0.97], controlling for sex, age, medical comorbidity, other specific MHCs, and index HbA1c value.

CONCLUSIONS

For most MHCs, diabetic patients with MHC in the VA health care system do not appear to receive less aggressive antiglycemic management. However, the subgroup with substance use disorders does appear to have excess likelihood of non-intensification; interventions targeting this high risk subgroup merit attention.

Distinct patterns of B-cell activation and priming by natural influenza virus infection versus inactivated influenza vaccination

BACKGROUND

The human B-cell response to natural influenza virus infection has not been extensively investigated at the polyclonal level.

METHODS

The overall B-cell response of patients acutely infected with the 2009 pandemic influenza A(H1N1)pdm09 virus (A[H1N1]pdm09) was analyzed by determining the reactivity of plasmablast-derived polyclonal antibodies (PPAbs) to influenza proteins. Recipients of inactivated influenza vaccine containing the same A(H1N1)pdm09 strain were studied for comparison.

RESULTS

During acute infection, robust plasmablast responses to the infecting virus were detected, characterized by a greater PPAb reactivity to the conserved influenza virus nuclear protein and to heterovariant and heterosubtypic hemagglutinins, in comparison to responses to the inactivated A(H1N1)pdm09 vaccine. In A(H1N1)pdm09 vaccinees, the presence of baseline serum neutralizing antibodies against A(H1N1)pdm09, suggesting previous exposure to natural A(H1N1)pdm09 infection, did not affect the plasmablast response to vaccination, whereas repeated immunization with inactivated A(H1N1)pdm09 vaccine resulted in significantly reduced vaccine-specific and cross-reactive PPAb responses.

CONCLUSIONS

Natural A(H1N1)pdm09 infection and inactivated A(H1N1)pdm09 vaccination result in very distinct patterns of B-cell activation and priming. These differences are likely to be associated with differences in protective immunity, especially cross-protection against heterovariant and heterosubtypic influenza virus strains.

Association between success rate and citation count of studies of radiofrequency catheter ablation for atrial fibrillation: possible evidence of citation bias

BACKGROUND

The preferential citation of studies with the highest success rates could exaggerate perceived effectiveness, particularly for treatments with widely varying published success rates such as radiofrequency catheter ablation for atrial fibrillation.

METHODS AND RESULTS

We systematically identified observational studies and clinical trials of radiofrequency catheter ablation of atrial fibrillation between 1990 and 2012. Generalized Poisson regression was used to estimate association between study success rate and total citation count, adjusting for sample size, journal impact factor, time since publication, study design, and whether first or last author was a consensus-defined pre-eminent expert. We identified 174 articles meeting our inclusion criteria (36 289 subjects). After adjustment only for time since publication, a 10-point increase above the mean in pooled reported success rates was associated with a 17.8% increase in citation count at 5 years postpublication (95% confidence interval, 7.1-28.4%; P<0.001). After additional adjustment for impact factor, sample size, randomized trial design, and pre-eminent expert authorship, the association remained significant (18.6% increase in citation count; 95% confidence interval, 7.6-29.6%; P<0.0001). In this full model, time since publication, impact factor, and pre-eminent expert authorship were significant covariates, whereas randomized control trial design and study sample size were not.

CONCLUSIONS

Among studies of radiofrequency catheter ablation of atrial fibrillation, high success rate was independently associated with citation count, which may indicate citation bias. To readers of the literature, radiofrequency catheter ablation of atrial fibrillation could be perceived to be more effective than the data supports. These findings may have implications for a wide variety of novel cardiovascular therapies.

Quantitative diet analysis of four mesopredators from a coral reef

The diets of four common mesopredator fishes were examined in the back-reef habitat of a subtropical fringing reef system during the summer months. Quantitative gut content analyses revealed that crustaceans, represented >60% of ingested prey (% mass) by the latticed sand-perch Parapercis clathrata, brown dottyback Pseudochromis fuscus and half-moon grouper Epinephelus rivulatus. Dietary analyses also provided insights into ontogenetic shifts. Juvenile P. fuscus ingested large numbers of crustaceans (amphipods and isopods); these small prey were rarely found in larger individuals (<1% of ingested mass). Fishes also made an important contribution to the diets of all three species representing 10-30% of ingested mass. Conversely, the sand lizardfish Synodus dermatogenys fed exclusively on fishes including clupeids, gobies and labrids. Differences in the gut contents of the four species recorded were not apparent using stable isotope analysis of muscle tissues. The similarity of δ(13) C values in muscle tissues suggested that carbon within prey was derived from primary producers, with comparable carbon isotope signatures to corals and macroalgae, whilst similarities in δ(15) N values indicated that all four species belonged to the same trophic level. Thus, interspecific differences between mesopredator diets were undetectable when using stable isotope analysis which suggests that detailed elucidation of trophic pathways requires gut content analyses.

Distinct cross-reactive B-cell responses to live attenuated and inactivated influenza vaccines

BACKGROUND

The immunological bases for the efficacies of the 2 currently licensed influenza vaccines, live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV), are not fully understood. The goal of this study was to identify specific B-cell responses correlated with the known efficacies of these 2 vaccines.

METHODS

We compared the B-cell and antibody responses after immunization with 2010/2011 IIV or LAIV in young adults, focusing on peripheral plasmablasts 6-8 days after vaccination.

RESULTS

The quantities of vaccine-specific plasmablasts and plasmablast-derived polyclonal antibodies (PPAbs) in IIV recipients were significantly higher than those in LAIV recipients. No significant difference was detected in the avidity of vaccine-specific PPAbs between the 2 vaccine groups. Proportionally, LAIV induced a greater vaccine-specific immunoglobulin A plasmablast response, as well as a greater plasmablast response to the conserved influenza nuclear protein, than IIV. The cross-reactive plasmablast response to heterovariant strains, as indicated by the relative levels of cross-reactive plasmablasts and the cross-reactive PPAb binding reactivity, was also greater in the LAIV group.

CONCLUSIONS

Distinct quantitative and qualitative patterns of plasmablast responses were induced by LAIV and IIV in young adults; a proportionally greater cross-reactive response was induced by LAIV.

Immune profiling of pregnant Toxoplasma-infected US and Colombia patients reveals surprising impacts of infection on peripheral blood cytokines

In North America (NA) and Europe, the majority of toxoplasmosis cases are benign and generally asymptomatic, whereas in South America (SA) toxoplasmosis is associated with much more severe symptoms in adults and congenitally infected children. The reasons for these differences remain unknown; currently, there is little information from patients in either region on how the immune system responds to infection with Toxoplasma gondii. Here, we report the relative abundance of 51 serum cytokines from acute and chronic toxoplasmosis cohorts of pregnant women from the United States, where approximately one-half of clinical isolates are Type II, and Colombia, where clinical isolates are generally "atypical" or Type I-like strains. Surprisingly, the results showed notably lower levels of 23 cytokines in acutely infected patients from the United States, relative to uninfected US controls. In acutely infected Colombian patients, however, only 8 cytokine levels differed detectably with 4 being lower and 4 higher relative to uninfected controls. Strikingly, there were also differences in the cytokine profiles of the chronically infected patients relative to uninfected controls in the US cohort. Hence, Toxoplasma appears to specifically impact levels of circulating cytokines, and our results may partly explain region-specific differences in the clinical spectrum of toxoplasmosis.

Do benzodiazepines reduce the effectiveness of exposure therapy for posttraumatic stress disorder?

OBJECTIVE

Benzodiazepines, other anxiolytics, or sedative hypnotics are prescribed for 30%-50% of posttraumatic stress disorder (PTSD) patients. Prior data and theory suggest that these medications may inhibit response to exposure therapy, one of the most effective PTSD treatments. The present post hoc study reanalyzed results from a psychotherapy trial to assess whether benzodiazepine use was associated with reduced response to exposure therapy.

METHOD

Between August 2002 and October 2005, 283 female veterans and soldiers meeting DSM-IV criteria for PTSD were randomly assigned to 10 weekly 90-minute sessions of either prolonged exposure (n = 140) or present-centered psychotherapy (n = 143). Benzodiazepine use (n = 57) or non-use (n = 226) at intake was not randomly assigned. Multilevel modeling was used to assess the effects of benzodiazepine status, psychotherapy condition, and their interaction on changes on the Clinician-Administered PTSD Scale and the PTSD Checklist during the treatment and 6-month follow-up periods.

RESULTS

Consistent with prior reports from these data, prolonged exposure psychotherapy produced greater reductions per week in PTSD symptoms than did present-centered psychotherapy (b = -0.48, P = .02). Patients prescribed benzodiazepines did not have weaker response to prolonged exposure, but demonstrated poorer posttreatment maintenance of gains from present-centered psychotherapy (b = -0.78, P < .001).

CONCLUSIONS

Prolonged exposure is a sufficiently robust treatment that patients who are taking benzodiazepines can benefit from it. It is unclear whether benzodiazepine use or other patient factors accounted for benzodiazepine recipients' poorer maintenance of gains in present-centered psychotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00032617.

Critical research needs for managing coral reef marine protected areas: perspectives of academics and managers

Marine protected areas (MPAs) are a primary policy instrument for managing and protecting coral reefs. Successful MPAs ultimately depend on knowledge-based decision making, where scientific research is integrated into management actions. Fourteen coral reef MPA managers and sixteen academics from eleven research, state and federal government institutions each outlined at least five pertinent research needs for improving the management of MPAs situated in Australian coral reefs. From this list of 173 key questions, we asked members of each group to rank questions in order of urgency, redundancy and importance, which allowed us to explore the extent of perceptional mismatch and overlap among the two groups. Our results suggest the mismatch among MPA managers and academics is small, with no significant difference among the groups in terms of their respective research interests, or the type of questions they pose. However, managers prioritised spatial management and monitoring as research themes, whilst academics identified climate change, resilience, spatial management, fishing and connectivity as the most important topics. Ranking of the posed questions by the two groups was also similar, although managers were less confident about the achievability of the posed research questions and whether questions represented a knowledge gap. We conclude that improved collaboration and knowledge transfer among management and academic groups can be used to achieve similar objectives and enhance the knowledge-based management of MPAs.

Effects of continuous positive airway pressure on neurocognitive function in obstructive sleep apnea patients: The Apnea Positive Pressure Long-term Efficacy Study (APPLES)

STUDY OBJECTIVE

To determine the neurocognitive effects of continuous positive airway pressure (CPAP) therapy on patients with obstructive sleep apnea (OSA).

DESIGN, SETTING, AND PARTICIPANTS

The Apnea Positive Pressure Long-term Efficacy Study (APPLES) was a 6-month, randomized, double-blind, 2-arm, sham-controlled, multicenter trial conducted at 5 U.S. university, hospital, or private practices. Of 1,516 participants enrolled, 1,105 were randomized, and 1,098 participants diagnosed with OSA contributed to the analysis of the primary outcome measures.

INTERVENTION

Active or sham CPAP MEASUREMENTS: THREE NEUROCOGNITIVE VARIABLES, EACH REPRESENTING A NEUROCOGNITIVE DOMAIN: Pathfinder Number Test-Total Time (attention and psychomotor function [A/P]), Buschke Selective Reminding Test-Sum Recall (learning and memory [L/M]), and Sustained Working Memory Test-Overall Mid-Day Score (executive and frontal-lobe function [E/F])

RESULTS

The primary neurocognitive analyses showed a difference between groups for only the E/F variable at the 2 month CPAP visit, but no difference at the 6 month CPAP visit or for the A/P or L/M variables at either the 2 or 6 month visits. When stratified by measures of OSA severity (AHI or oxygen saturation parameters), the primary E/F variable and one secondary E/F neurocognitive variable revealed transient differences between study arms for those with the most severe OSA. Participants in the active CPAP group had a significantly greater ability to remain awake whether measured subjectively by the Epworth Sleepiness Scale or objectively by the maintenance of wakefulness test.

CONCLUSIONS

CPAP treatment improved both subjectively and objectively measured sleepiness, especially in individuals with severe OSA (AHI > 30). CPAP use resulted in mild, transient improvement in the most sensitive measures of executive and frontal-lobe function for those with severe disease, which suggests the existence of a complex OSA-neurocognitive relationship.

CLINICAL TRIAL INFORMATION

Registered at clinicaltrials.gov. Identifier: NCT00051363.

CITATION

Kushida CA; Nichols DA; Holmes TH; Quan SF; Walsh JK; Gottlieb DJ; Simon RD; Guilleminault C; White DP; Goodwin JL; Schweitzer PK; Leary EB; Hyde PR; Hirshkowitz M; Green S; McEvoy LK; Chan C; Gevins A; Kay GG; Bloch DA; Crabtree T; Demen WC. Effects of continuous positive airway pressure on neurocognitive function in obstructive sleep apnea patients: the Apnea Positive Pressure Long-term Efficacy Study (APPLES). SLEEP 2012;35(12):1593-1602.

High-anxious individuals show increased chronic stress burden, decreased protective immunity, and increased cancer progression in a mouse model of squamous cell carcinoma

In spite of widespread anecdotal and scientific evidence much remains to be understood about the long-suspected connection between psychological factors and susceptibility to cancer. The skin is the most common site of cancer, accounting for nearly half of all cancers in the US, with approximately 2-3 million cases of non-melanoma cancers occurring each year worldwide. We hypothesized that a high-anxious, stress-prone behavioral phenotype would result in a higher chronic stress burden, lower protective-immunity, and increased progression of the immuno-responsive skin cancer, squamous cell carcinoma. SKH1 mice were phenotyped as high- or low-anxious at baseline, and subsequently exposed to ultraviolet-B light (1 minimal erythemal dose (MED), 3 times/week, 10-weeks). The significant strengths of this cancer model are that it uses a normal, immunocompetent, outbred strain, without surgery/injection of exogenous tumor cells/cell lines, and produces lesions that resemble human tumors. Tumors were counted weekly (primary outcome), and tissues collected during early and late phases of tumor development. Chemokine/cytokine gene-expression was quantified by PCR, tumor-infiltrating helper (Th), cytolytic (CTL), and regulatory (Treg) T cells by immunohistochemistry, lymph node T and B cells by flow cytometry, adrenal and plasma corticosterone and tissue vascular-endothelial-growth-factor (VEGF) by ELISA. High-anxious mice showed a higher tumor burden during all phases of tumor development. They also showed: higher corticosterone levels (indicating greater chronic stress burden), increased CCL22 expression and Treg infiltration (increased tumor-recruited immuno-suppression), lower CTACK/CCL27, IL-12, and IFN-γ gene-expression and lower numbers of tumor infiltrating Th and CTLs (suppressed protective immunity), and higher VEGF concentrations (increased tumor angiogenesis/invasion/metastasis). These results suggest that the deleterious effects of high trait anxiety could be: exacerbated by life-stressors, accentuated by the stress of cancer diagnosis/treatment, and mediate increased tumor progression and/or metastasis. Therefore, it may be beneficial to investigate the use of chemotherapy-compatible anxiolytic treatments immediately following cancer diagnosis, and during cancer treatment/survivorship.

A method for estimating normative distributions for study-specific populations of clinical trials

For any particular psychological instrument, published normative distributions have been derived in one to at most a few specific "reference" populations. Here a method is provided for estimating a normative distribution pertinent to the specific population being evaluated in a randomized clinical trial. Normative quantiles are obtained using quantile regression, a method chosen for its flexibility in that no assumptions are made about the parametric form (e.g., Gaussian) of the normative distribution to be estimated. Outcome is regressed on disease severity for the τth quantile using that sample of consented participants who were not randomized because they fell below the trial's disease severity entry criterion. The τth quantile of the normative distribution is then estimated by the intercept of this fitted regression function, which corresponds to severity of zero. Additional covariates that explain variation in outcome may be included to permit adjustment for shifts in their distributions between the randomized and non-randomized samples. The method is illustrated using data on a depression instrument (GRID Hamilton Rating Scale for Depression) and a neurocognitive instrument (CogScreen Pathfinder Number) from a multicenter clinical trial in sleep apnea patients.

Limited efficacy of inactivated influenza vaccine in elderly individuals is associated with decreased production of vaccine-specific antibodies

During seasonal influenza epidemics, disease burden is shouldered predominantly by the very young and the elderly. Elderly individuals are particularly affected, in part because vaccine efficacy wanes with age. This has been linked to a reduced ability to induce a robust serum antibody response. Here, we show that this is due to reduced quantities of vaccine-specific antibodies, rather than a lack of antibody avidity or affinity. We measured levels of vaccine-specific plasmablasts by ELISPOT 1 week after immunization of young and elderly adults with inactivated seasonal influenza vaccine. Plasmablast-derived polyclonal antibodies (PPAbs) were generated from bulk-cultured B cells, while recombinant monoclonal antibodies (re-mAbs) were produced from single plasmablasts. The frequency of vaccine-specific plasmablasts and the concentration of PPAbs were lower in the elderly than in young adults, whereas the yields of secreted IgG per plasmablast were not different. Differences were not detected in the overall vaccine-specific avidity or affinity of PPAbs and re-mAbs between the 2 age groups. In contrast, reactivity of the antibodies induced by the inactivated seasonal influenza vaccine toward the 2009 pandemic H1N1 virus, which was not present in the vaccine, was higher in the elderly than in the young. These results indicate that the inferior antibody response to influenza vaccination in the elderly is primarily due to reduced quantities of vaccine-specific antibodies. They also suggest that exposure history affects the cross-reactivity of vaccination-induced antibodies.

Mental illness-related disparities in length of stay: algorithm choice influences results

Methodological challenges arise when one uses various Veterans Health Administration (VHA) data sources, each created for distinct purposes, to characterize length of stay (LOS). To illustrate this issue, we examined how algorithm choice affects conclusions about mental health condition (MHC)-related differences in LOS for VHA patients with diabetes nationally (n = 784,321). We assembled a record-level database of all fiscal year (FY) 2003 inpatient care. In 10 steps, we sequentially added instances of inpatient care from various VHA sources. We processed databases in three stages, truncating stays at the beginning and end of FY03 and consolidating overlapping stays. For patients with MHCs versus those without MHCs, mean LOS was 17.7 versus 13.6 days, respectively (p < 0.001), for the crudest algorithm and 37.2 versus 21.7 days, respectively (p < 0.001), for the most refined algorithm. Researchers can improve the quality of data applied to VHA systems redesign by applying methodological considerations raised by this study to inform LOS algorithm choice.

Anemia in older persons: etiology and evaluation

The aim of this study was to prospectively determine the etiology of anemia in a cohort of community-dwelling older outpatients with a comprehensive hematologic evaluation. Participants were men and women age 65 and older with anemia as defined by World Health Organization criteria recruited from outpatient hematology clinics at Stanford Hospital and Clinics (SHC) and Veterans Affairs Palo Alto Health Care System (VAPAHCS). Each participant underwent a history and physical examination, followed by a comprehensive hematologic evaluation, which in all participants included complete blood count, red cell indices, review of the blood smear, and assessment of vitamin B12, folate, iron status and renal function. Additional evaluation was obtained by clinical providers as per their discretion. 190 participants enrolled and completed the evaluation. Twelve percent of participants had iron deficiency anemia. Of those with iron deficiency in whom there was follow-up information, half normalized their hemoglobin in response to iron repletion, and half did not. Thirty-five percent of participants had unexplained anemia. Those with unexplained anemia had mildly increased inflammatory markers compared to non-anemic controls, and, at the lower hemoglobin ranges had relatively low erythropoietin levels. Sixteen percent of participants were categorized as being "suspicious for myelodysplastic syndrome." Thus, even with comprehensive hematologic evaluation, unexplained anemia is common in older anemic outpatients. Iron deficiency anemia is also common and can be difficult to diagnose, and frequently the anemia is not fully corrected with iron repletion.

Advantages of Joint Modeling of Component HIV Risk Behaviors and Non-Response: Application to Randomized Trials in Cocaine-Dependent and Methamphetamine-Dependent Populations

The HIV risk-taking behavior scale (HRBS) is an 11-item instrument designed to assess the risks of HIV infection due to self-reported injection-drug use and sexual behavior. A retrospective analysis was performed on HRBS data collected from approximately 1,000 participants pooled across seven clinical trials of pharmacotherapies for either the treatment of cocaine dependence or methamphetamine dependence. Analysis faced three important challenges. The sample contained a high proportion of missing assessments after randomization. Also, the HRBS scale consists of two distinct behavioral components which may or may not coincide in response patterns. In addition, distributions of responses on the subscales were highly concentrated at just a few values (e.g., 0, 6). To address these challenges, a single probit regression model was fit to three outcomes variables simultaneously - the two subscale totals plus an indicator variable for assessments not obtained (non-response). This joint-outcome regression model was able to identify that those who left assessment early had higher self-reported risk of injection-drug use and lower self-reported risky sexual behavior because the model was able to draw on information on associations among the three outcomes collectively. These findings were not identified in analyses performed on each outcome separately. No evidence for an effect of pharmacotherapies was observed, except to reduce missing assessments. Univariate-outcome modeling is not recommended for the HRBS.

Military-related sexual trauma among Veterans Health Administration patients returning from Afghanistan and Iraq

We examined military-related sexual trauma among deployed Operation Enduring Freedom and Operation Iraqi Freedom veterans. Of 125 729 veterans who received Veterans Health Administration primary care or mental health services, 15.1% of the women and 0.7% of the men reported military sexual trauma when screened. Military sexual trauma was associated with increased odds of a mental disorder diagnosis, including posttraumatic stress disorder, other anxiety disorders, depression, and substance use disorders. Sexual trauma is an important postdeployment mental health issue in this population.

Association between Genotype of the Serotonin Transporter-Linked Polymorphic Region of the Serotonin Transporter Gene and Age of Onset of Methamphetamine Use: a Preliminary Analysis

Early-onset methamphetamine use increases the lifetime prevalence of methamphetamine dependence. An earlier onset of methamphetamine use leads to greater damage to the terminal ends of serotonin neurons, more reduction in serotonin transporter (5-HTT) density, and an increased propensity toward further methamphetamine use. Because the 5-HTT-linked polymorphic region (5'-HTTLPR) within the promoter region of the 5-HTT gene leads to differential expression of the 5-HTT, we examined, for the first time, whether there is a differential association between the long (L) and short (S) alleles of the 5'-HTTLPR and the age of first methamphetamine use (AMU). The study included 120 methamphetamine-dependent adults of European descent. Diagnosis of methamphetamine dependence and AMU were collected using structured questionnaires, and the 5'-HTTLPR genotypes were determined using the polymerase chain reaction-restriction fragment length polymorphism method. Statistical analysis with the general linear model detected a significant interactive effect of 5'-HTTLPR genotypes (SS vs. L-carriers) and gender, associated with AMU (F = 3.99; p = 0.048). Further analysis of 5'-HTTLPR effects on AMU in males and females separately showed that the SS genotype compared with L-carriers had about two times greater risk of an earlier onset of methamphetamine use in men (hazard ratio = 1.839; 95% confidence interval = 1.042-3.246; p = 0.036) but not in women. Together, our findings in this preliminary study suggest a greater risk for earlier onset methamphetamine use associated with the SS genotype of the 5'-HTTLPR among methamphetamine-dependent Caucasian males.

Short-term stress enhances cellular immunity and increases early resistance to squamous cell carcinoma

In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposure would enhance protective immunity and increase resistance to SCC. Control and short-term stress groups were treated identically except that the short-term stress group was restrained (2.5h) before each of nine UV-exposure sessions (minimum erythemal dose, 3-times/week) during weeks 4-6 of the 10-week UV exposure protocol. Tumors were measured weekly, and tissue collected at weeks 7, 20, and 32. Chemokine and cytokine gene expression was quantified by real-time PCR, and CD4+ and CD8+ T cells by flow cytometry and immunohistochemistry. Compared to controls, the short-term stress group showed greater cutaneous T-cell attracting chemokine (CTACK)/CCL27, RANTES, IL-12, and IFN-gamma gene expression at weeks 7, 20, and 32, higher skin infiltrating T cell numbers (weeks 7 and 20), lower tumor incidence (weeks 11-20) and fewer tumors (weeks 11-26). These results suggest that activation of short-term stress physiology increased chemokine expression and T cell trafficking and/or function during/following UV exposure, and enhanced Type 1 cytokine-driven cell-mediated immunity that is crucial for resistance to SCC. Therefore, the physiological fight-or-flight stress response and its adjuvant-like immuno-enhancing effects, may provide a novel and important mechanism for enhancing immune system mediated tumor-detection/elimination that merits further investigation.

Differential effects of insulin sensitivity on androgens in obese women with polycystic ovary syndrome or normal ovulation

The differential effects of insulin sensitivity and adiposity on androgen concentrations in women with polycystic ovary syndrome (PCOS) are unclear. To address this issue, we divided 43 overweight women into 4 groups based on both their clinical classification (PCOS or normal) and whether they were insulin resistant (IR) or insulin sensitive (IS) by their steady-state plasma glucose concentrations. Total testosterone concentrations were significantly increased as a function of both clinical classification (PCOS vs normal, P < .0001) and steady-state plasma glucose concentration (IR vs IS, P = .002). Mean testosterone concentrations were higher in PCOS-IR compared with PCOS-IS, normal-IR, or normal-IS women (P < .005). In addition, there was a statistically significant interaction (P = .03) between clinical classification (PCOS vs normal) and insulin sensitivity (IR vs IS) for testosterone concentrations. In contrast, androstenedione concentrations were higher in women with PCOS (P = .001), irrespective of whether they were IR or IS (P = .31); and no interaction between clinical classification and insulin sensitivity was discerned (P = .34). These results indicate that both PCOS and insulin resistance independently contributed to increased total testosterone concentrations within a group of overweight/obese women. These findings are consistent with the hypothesis that the ovaries of women with PCOS are hypersensitive to the ability of insulin to increase testosterone production and that the more insulin resistant the patient, the higher the testosterone concentration. In contrast, androstenedione concentrations seem to be independent of differences in insulin resistance. Our findings emphasize the need to increase understanding of the factors that modulate ovarian androgen secretion.

Simple counts of ADL dependencies do not adequately reflect older adults' preferences toward states of functional impairment

OBJECTIVE

To use unweighted counts of dependencies in activities of daily living (ADLs) to assess the impact of functional impairment requires an assumption of equal preferences for each ADL dependency. To test this assumption, we analyzed standard gamble (SG) utilities of single and combination ADL dependencies among older adults.

STUDY DESIGN AND SETTING

Four hundred older adults used multimedia software (FLAIR1) to report SG utilities for their current health and hypothetical health states of dependency in each of 7 ADLs and 8 of 30 combinations of ADL dependencies.

RESULTS

Utilities for health states of multiple ADL dependencies were often greater than for states of single ADL dependencies. Dependence in eating, which is the ADL dependency with the lowest utility rating of the single ADL dependencies, ranked lower than 7 combination states. Similarly, some combination states with fewer ADL dependencies had lower utilities than those with more ADL dependencies. These findings were consistent across groups by gender, age, and education.

CONCLUSION

Our results suggest that the count of ADL dependencies does not adequately represent the utility for a health state. Cost-effectiveness analyses and other evaluations of programs that prevent or treat functional dependency should apply utility weights rather than relying on simple ADL counts.

Influence of prior influenza vaccination on antibody and B-cell responses

Currently two vaccines, trivalent inactivated influenza vaccine (TIV) and live attenuated influenza vaccine (LAIV), are licensed in the USA. Despite previous studies on immune responses induced by these two vaccines, a comparative study of the influence of prior influenza vaccination on serum antibody and B-cell responses to new LAIV or TIV vaccination has not been reported. During the 2005/6 influenza season, we quantified the serum antibody and B-cell responses to LAIV or TIV in adults with differing influenza vaccination histories in the prior year: LAIV, TIV, or neither. Blood samples were collected on days 0, 7–9 and 21–35 after immunization and used for serum HAI assay and B-cell assays. Total and influenza-specific circulating IgG and IgA antibody secreting cells (ASC) in PBMC were detected by direct ELISPOT assay. Memory B cells were also tested by ELISPOT after polyclonal stimulation of PBMC in vitro. Serum antibody, effector, and memory B-cell responses were greater in TIV recipients than LAIV recipients. Prior year TIV recipients had significantly higher baseline HAI titers, but lower HAI response after vaccination with either TIV or LAIV, and lower IgA ASC response after vaccination with TIV than prior year LAIV or no vaccination recipients. Lower levels of baseline HAI titer were associated with a greater fold-increase of HAI titer and ASC number after vaccination, which also differed by type of vaccine. Our findings suggest that the type of vaccine received in the prior year affects the serum antibody and the B-cell responses to subsequent vaccination. In particular, prior year TIV vaccination is associated with sustained higher HAI titer one year later but lower antibody response to new LAIV or TIV vaccination, and a lower effector B-cell response to new TIV but not LAIV vaccination.

Phenotypic changes in influenza-specific CD8+ T cells after immunization of children and adults with influenza vaccines

The effect of trivalent inactivated influenza vaccine (TIV) or live attenuated influenza vaccine (LAIV) on the phenotypes of circulating influenza-specific CD8+ T cells was analyzed by interferon (IFN)-gamma flow cytometry and tetramer staining. In adults, the expression of the T cell differentiation marker CD27 on virus-specific CD8+ T cells decreased after LAIV but increased after TIV. In children, expression of the cytotoxicity molecule perforin in influenza-specific CD8+ T cells increased after TIV but not after LAIV. Among children aged 6 months to 4 years who had not been vaccinated previously and who received 2 doses of TIV, CD27 expression decreased after each dose, whereas perforin expression increased after the second dose. These findings indicate that the phenotypic changes of influenza-specific CD8+ T cells differ depending on the type of vaccine and the age of the vaccinee. These differences are potentially affected by the different routes of vaccination and pathways of antigen presentation for TIV and LAIV.

Posttranslational regulation of I-Ed by affinity for CLIP

Several MHC class II alleles linked with autoimmune diseases form unusually low stability complexes with CLIP, leading us to hypothesize that this is an important feature contributing to autoimmune pathogenesis. To investigate cellular consequences of altering class II/CLIP affinity, we evaluated invariant chain (Ii) mutants with varying CLIP affinity for a mouse class II allele, I-E(d), which has low affinity for wild-type CLIP and is associated with a mouse model of spontaneous, autoimmune joint inflammation. Increasing CLIP affinity for I-E(d) resulted in increased cell surface and total cellular abundance and half-life of I-E(d). This reveals a post-endoplasmic reticulum chaperoning capacity of Ii via its CLIP peptides. Quantitative effects on I-E(d) were less pronounced in DM-expressing cells, suggesting complementary chaperoning effects mediated by Ii and DM, and implying that the impact of allelic variation in CLIP affinity on immune responses will be highest in cells with limited DM activity. Differences in the ability of cell lines expressing wild-type or high-CLIP-affinity mutant Ii to present Ag to T cells suggest a model in which increased CLIP affinity for class II serves to restrict peptide loading to DM-containing compartments, ensuring proper editing of antigenic peptides.

Humoral and cellular immune responses in children given annual immunization with trivalent inactivated influenza vaccine

BACKGROUND

There have been no prior reports of the frequency of circulating influenza-specific, interferon gamma-producing memory CD4+ and CD8+ T-cells in healthy children who have received multiple influenza immunizations.

METHODS

We evaluated 21 previously immunized children, ages 3 to 9 years, before and 1 month after administration of trivalent inactivated influenza vaccine. Frequencies of influenza-specific CD4+ and CD8+ T-cells stimulated with trivalent inactivated influenza vaccine or A/Panama (H3N2) virus were determined by flow cytometry, and antibody responses to vaccine strains and a drifted H3N2 strain were measured by hemagglutination inhibition assay and neutralizing antibody assays.

RESULTS

Mean change in CD4+ and in CD8+ T-cell frequencies after immunization was 0.01% (P > 0.39) with postimmunization CD4+ frequencies higher than CD8+ frequencies. Children with more previous vaccinations had a higher baseline frequency of CD4+ T-cells (P = 0.0002) but a smaller increase or even a decline from baseline after immunization (P = 0.003). An association between age and change in frequency was not detected. Baseline geometric mean titers (GMTs) and seroprotection rates were significantly higher in older children against A/Panama (neutralizing baseline GMT, P = 0.0488) and A/New Caledonia (hemagglutination inhibition baseline GMT and seroprotection, P < 0.0297). Baseline GMTs against B/Hong Kong were not associated with age or quantity of prior vaccinations.

CONCLUSIONS

These findings suggest that children may plateau in CD4+ T-cell responses to influenza antigens with repeated exposures and that the number of exposures may play a large role in building a memory CD4+ T-cell response to influenza A, perhaps independently from age.