Catherine Fillee

The moderating impact of emotional intelligence on free cortisol responses to stress.

The construct of trait emotional intelligence (trait EI) refers to the individual differences in the perception, processing, regulation and utilization of emotional information. Several studies have found that trait EI was a significant moderator of subjective responses (e.g., mood deterioration, emotional intensity, action tendencies, bodily sensations) to both natural and laboratory stressors. The present study aims at extending these findings by examining whether trait EI also moderates the biological (i.e., cortisol) response to stress. To this end, 56 participants were assigned to either a neutral or a stressful condition (public speech task) and psychological and cortisol reactivity were examined. Results revealed that higher trait EI scores were associated with significantly lower reactivity to stress at both psychological (i.e., mood deterioration) and biological (i.e., salivary cortisol) levels. Additional analyses revealed that trait EI had incremental validity to predict stress reactivity over and above social desirability, alexithymia and the five-factor model of personality.

Cortisol awakening response (CAR)’s flexibility leads to larger and more consistent associations with psychological factors than CAR magnitude

The cortisol awakening response (CAR) is increasingly recognized as a potential biological marker of psychological and physical health status. Yet, the CAR literature is replete with contradictory results: both supposedly protective and vulnerability psychosocial factors have been associated with both increased and decreased CAR. In this study, we tested the hypothesis that the CAR flexibility would be a better indicator of psychological status than CAR magnitude. Forty-two men measures of happiness, perceived stress and neuroticism, and took saliva samples immediately on awakening, then at 15, 30, 45 and 60min post-awakening on three study days (i.e., Sunday, Monday and Tuesday). When considering the CAR magnitude, our effects perfectly reflect the inconsistencies previously observed in the literature (i.e., the main effects of the psychological predictors are not consistent with each other, and the effect of one predictor on a given day contradicts the effect of the same predictor on another day). However, considering the CAR flexibility leads to a fully consistent pattern: protective factors (i.e., high happiness, low stress, low neurotiscim) are associated with a flexible CAR (i.e., lower CAR during weekends compared to workdays) whereas vulnerability factors (i.e., low happiness, high stress, high neurotiscim) are associated with a stiff CAR (i.e., same magnitude during weekends and workdays). We conclude that considering the CAR flexibility (e.g., between weekends and workdays) rather than the traditional CAR magnitude might be a way to understand the apparent conflicts in the CAR literature.

Mucosal and systemic immune responses to Mycobacterium tuberculosis antigen 85A following its co-delivery with CpG, MPLA or LTB to the lungs in mice

Pulmonary vaccination is a promising route for immunization against tuberculosis because the lung is the natural site of infection with Mycobacterium tuberculosis. Yet, adjuvants with a suitable safety profile need to be found to enhance mucosal immunity to recombinant antigens. The aim of this study was to evaluate the immunogenicity, the safety and the protective efficacy of a subunit vaccine composed of the immunodominant mycolyl-transferase antigen 85A (Ag85A) and one of three powerful mucosal adjuvants: the oligodeoxynucleotide containing unmethylated cytosine-phosphate-guanine motifs (CpG), the monophosphoryl lipid A of Salmonella minnesota (MPLA) or the B subunit of heat-labile enterotoxin of Escherichia coli (LTB). BALB/c mice were vaccinated in the deep lungs. Our results showed that lung administration of these adjuvants could specifically induce different types of T cell immunity. Both CpG and MPLA induced a Th-1 type immune response with significant antigen-specific IFN-γ production by spleen mononuclear cells in vitro and a tendency of increased IFN-γ in the lungs. Moreover, MPLA triggered a Th-17 response reflected by high IL-17A levels in the spleen and lungs. By contrast, LTB promoted a Th-2 biased immune response, with a production of IL-5 but not IFN-γ by spleen mononuclear cells in vitro. CpG did not induce inflammation in the lungs while LTB and MPLA showed a transient inflammation including a neutrophil influx one day after pulmonary administration. Pulmonary vaccination with Ag85A without or with MPLA or LTB tended to decrease bacterial counts in the spleen and lungs following a virulent challenge with M. tuberculosis H37Rv. In conclusion, CpG and MPLA were found to be potential adjuvants for pulmonary vaccination against tuberculosis, providing Th-1 and Th-17 immune responses and a good safety profile.

Targeting the deep lungs, Poloxamer 407 and a CpG oligonucleotide optimize immune responses to Mycobacterium tuberculosis antigen 85A following pulmonary delivery

The current Bacille Calmette-Guérin vaccine provides variable protection against tuberculosis and new vaccination approaches are urgently needed. Pulmonary vaccination could be the best way to induce a protective immunity against Mycobacterium tuberculosis as it targets its natural site of infection. The aim of this study was to investigate the potential of Poloxamer 407 (P407) combined with a CpG oligonucleotide (CpG) to enhance immune responses to M. tuberculosis antigen 85A (Ag85A) following pulmonary delivery in BALB/c mice. An additional goal of this study was to localize the optimal delivery site of Ag85A within the lungs for generating the most intense immunity. We also investigated the capacity of P407 to prolong the residence time of the antigen within the lungs and we studied the safety of the adjuvants following pulmonary delivery. Targeting the antigen to the deep lungs produced more intense specific immune responses than targeting it to the upper airways. P407 and CpG further increased humoral immune responses and splenocyte proliferation in vitro. CpG strongly increased the Th-1 immune response with high IgG2a/IgG1 ratio, high IFN-γ and TNF-α productions by spleen mononuclear cells in vitro. P407 tended to induce a Th-2 response, as indicated by the slight decrease in IgG2a/IgG1 ratio and the slight increase in IL-5 levels. The combination of P407 and CpG produced the highest Th-1 and Th-17 responses by generating IFN-γ, TNF-α, IL-2, and IL-17A cytokines. Targeting the antigen to the deep lungs and the presence of P407 increased the residence time of the antigen within the lungs. This might explain the enhancement of immune responses induced by these factors. CpG did not induce inflammation in the lungs while P407 produced a reversible alteration of the alveolo-capillary barrier. Adding CpG to P407 did not further increase this alteration of the alveolo-capillary barrier. In conclusion, delivery of Ag85A formulated in a combination of P407 and CpG to the deep lungs induced strong immune responses, with a polyfunctional T cells phenotype.

Prostate cancer screening: clinical impact of WHO calibration of Beckman Coulter Access prostate-specific antigen assays.

Abstract Background: The goal of this study was to evaluate the clinical impact of using the same total prostate-specific antigen (tPSA) and free PSA (fPSA) assays calibrated with World Health Organization (WHO) materials or with Hybritech Tandem-R calibrator. Methods: From the initial correlation study that included 150 patients, the clinical impact of the WHO calibration was simulated using a large cohort (n=4548) of referred patients. Interim reports of the European Study of Screening for Prostate Cancer (ERSPC) were used to evaluate the clinical outcomes of patients and the risk of prostate cancer (PCa). Results: WHO calibration of tPSA assays leads to a reduction of about 20% in measured results (tPSA WHO=0.81 tPSA Hybritech+0.04; fPSA WHO=0.78 fPSA Hybritech+0.00; %fPSA WHO=0.92 %fPSA Hybritech+0.00). The simulation showed that the WHO calibration is associated with a risk of missing 15% of PCa. Conclusions: The discrepancies between the two calibrations lead to significant clinical misinterpretation with decreased detection of PCa if tPSA cut-off thresholds are not adjusted. Clin Chem Lab Med 2010;48:285–8.

Nicotinamide enhances apoptosis of G(M)-CSF-treated neutrophils and attenuates endotoxin-induced airway inflammation in mice

Neutrophils constitute the first line of host defense against invading microorganisms. Yet their removal from the inflammatory environment is fundamental for injury restraint and resolution of inflammation. Nicotinamide, a component of vitamin B(3), is known to modulate cell survival. In this study, we assessed the influence of nicotinamide on neutrophil apoptosis, both in vitro and in vivo in a mouse model of endotoxin-induced lung inflammation. In vitro, nicotinamide promoted apoptosis of human blood neutrophils in a dose-dependent manner in the presence of the apoptosis inhibitors granulocyte colony-stimulating factor and granulocyte/macrophage colony-stimulating factor. The highest concentration of nicotinamide completely neutralized the pro-survival effect of granulocyte (macrophage) colony-stimulating factor. Nicotinamide proapoptotic effect was associated with enhanced caspase-3 activity. In addition, nicotinamide slightly reduced neutrophil chemotaxis in vitro. In vivo, pulmonary nicotinamide delivery decreased the levels of cellular and biochemical inflammation markers and increased the percentage of apoptotic neutrophils in bronchoalveolar lavages. Our findings suggest that nicotinamide is an apoptotic stimulus for neutrophils, thereby contributing to the resolution of neutrophilic inflammation in the lungs.

Results of the recalibration of creatinine measurement with the modular Beckman Coulter Jaffe creatinine method.

Abstract Background: Serum creatinine is important for detecting the beginning of a decline in kidney function. The Beckman Coulter Jaffe reagents for measuring creatinine have been standardized to the internationally accepted reference method: isotope dilution mass spectrometry (IDMS). The impact of this recalibration on the Beckman Coulter® modular or cup (stat) Jaffe method is studied. Methods: Recalibrated Jaffe (calibrator set points IDMS traceable) and classic National Institute of Standards and Technology (NIST) creatinine methods (traceable to NIST 914a) were compared with an enzymatic method (Sentinel, traceable to NIST SRM 967). All measurements were performed on Synchron DxC 800 systems. Imprecision of the routine methods was studied using the Clinical and Laboratory Standards Institute (CLSI) protocols and laboratory quality survey. Thirteen plasma pools, with concentrations <354 μmol/L, were analyzed with a gas chromatography isotope dilution mass spectrometry (GC-IDMS) method and routine methods. Total error of 8.2% based on biological variability, set on the GC-IDMS values and acceptance criteria (bias <5%, imprecision <8% at concentrations ≥88.4 μmol/L and a maximum 10% increase in the relative error of estimated glomerular filtration rate (eGFR) of the National Kidney Disease Educational Program (NKDEP) were used for evaluating analytical performance of the routine methods studied. Results: After recalibration of the Jaffe method, median bias (μmol/L) decreased from 12.4 (95% CI: 9.1–21.2) to 7.3 (95% CI: 1.5–10.5). Imprecision of the Jaffe method is in agreement with the claim of the manufacturer, namely <9 μmol/L or <3% below or above 292 μmol/L. Below creatinine of 88.4 μmol/L, imprecision of the recalibrated Jaffe and enzymatic methods is between 4.1% and 6.9%, and 5.0% and 7.1%, respectively, and significantly different (p=0.02 for both the Jaffe and enzymatic methods) from the goal, based on biological variability, of 2.7%. For the adult pools, all recalibrated Jaffe and enzymatic results fall within the total error of 8.2%. In the pediatric samples, one-third of the recalibrated Jaffe and three of the six enzymatic results fall within this total error goal. Conclusions: Recalibration significantly reduced bias of the Jaffe method. For pediatric samples, recalibrated Jaffe results do not comply with either the imprecision goal or the total error based on biological variability. Adult recalibrated Jaffe results are in compliance with the goals based on biological variability and with the acceptance criteria from the NKDEP.

Laboratory automation: how will you select the boarding assays?

*Corresponding author: Pr. Damien Gruson, Pôle de recherche en Endocrinologie, Diabète et Nutrition (EDIN), Institut de Recherche Expérimentale et Clinique, Cliniques Universitaires St-Luc and Université Catholique de Louvain, Tour Claude Bernard, 54 Avenue Hippocrate, 1200 Brussels, Belgium, Phone: +32 2 7646747, Fax: +32 2 7646930, E-mail: damien.gruson@uclouvain.be Catherine Fillée: Department of Laboratory Medicine, Cliniques Universitaires St-Luc and Université Catholique de Louvain, Brussels, Belgium

How to optimize the prescription of laboratory tests? Success and failures in an academic hospital.

Abstract In the context of the flat-rate reimbursements in healthcare, we reviewed physicians’ behavior towards laboratory test ordering. We demonstrated how it could be improved when a specific stage of the patient management is considered. We took a multi-step approach to analyze the laboratory test orders in the context of planned laparoscopic cholecystectomy in a general teaching hospital. A reference order set was defined through a collaborative analysis between clinicians and laboratory physicians. The clinical and financial impacts were then evaluated over a period of 24 months. After the introduction of the reference order set, the number of laboratory tests per order decreased significantly for patients with cholecystitis of low severity. Above the monitoring of repeated orderings during a single stay, the major impacts were achieved by a drastic reduction of inappropriate orders, particularly in the field of bacteriology. The main effects of the order set were maintained throughout a follow-up period of 24 months. Our study demonstrated that, when considering laboratory test ordering optimization, reference order sets could achieve high levels of efficiency. To ensure high compliance to reference order sets, extensive collaboration between clinicians and laboratory physician is mandatory even if very sophisticated information systems are available.

A LARGE INTRAPERITONEAL RESIDUAL VOLUME HAMPERS ADEQUATE VOLUMETRIC ASSESSMENT OF OSMOTIC CONDUCTANCE TO GLUCOSE.

Background: In end-stage renal disease patients treated with peritoneal dialysis (PD), the osmotic conductance to glucose (OCG) represents the intrinsic ability of the membrane to transport water in response to a crystalloid osmotic gradient. A progressive loss of OCG in long-term PD patients indicates the development of fibrosis in the peritoneal interstitium, and helps identify patients at risk for encapsulating peritoneal sclerosis. The double mini-peritoneal equilibration test (PET) has been proposed as a simple method to assess OCG using the difference in initial ultrafiltration rates generated by 2 successive dwells using 1.36% and 3.86% glucose-based, 1-h PET. However, the presence of a large peritoneal residual volume (RV) may potentially interfere with the correct evaluation of drained volumes, limiting the reliability of OCG assessed by the double mini-PET. Methods: We retrospectively reviewed data from 53 peritoneal function tests in 35 consecutive PD patients starting PD at our center between March 2013 and March 2017. The test consisted of a uni-PET (double mini-PET combined with a 3.86%, 4-h PET) performed at PD start, then yearly. In addition to peritoneal solute transport rate and net ultrafiltration, the tests provided information about osmotic water transport (OCG, sodium sieving, and free-water transport) as well as the RV estimated from albumin dilution. Results: Contrary to sodium sieving, net ultrafiltration, and free-water transport, OCG did not correlate with any of the other parameters of osmotic water transport. In multivariate regression analyses, the RV was identified as the only determinant of OCG, while it did not alter the robust association between sodium sieving/free-water transport and their respective determinants. Considering only baseline tests or the whole series of tests, the presence of a large intraperitoneal RV was associated with discrepant values between OCG and sodium sieving, and with an artificial increase in OCG. Conclusions: A large RV leads to significant overestimation of OCG using the double mini-PET, potentially reducing the ability of OCG to identify patients with progressive fibrosis in the peritoneal interstitium. On the other hand, sieving of the dialysate sodium, a biochemical surrogate for OCG, is independent of the RV and may therefore be more reliable. A call for caution is warranted in patients with a large RV to avoid misinterpretation of OCG values derived from the double mini-PET.