The 13C glucose breath test accurately identifies insulin resistance in people with type 1 diabetes.

OBJECTIVE: This study investigated whether the delta-over-baseline of exhaled 13CO2 (Δ13CO2), generated from a 13C glucose breath test (13C-GBT), measured insulin resistance (IR) in people with type 1 diabetes, using the hyperinsulinemic-euglycemic clamp (HEC) as reference method. Secondary objective was to compare the 13C-GBT with the estimated glucose disposal rate (eGDR). METHODS: A 40 mU/m2/min HEC and two separate 13C-GBTs (euglycemic with insulin bolus and hyperglycemic without bolus) were consecutively performed in 44 adults with type 1 diabetes with varying body compositions. eGDR was calculated based on HbA1c, presence of hypertension and waist circumference. RESULTS: Mean M-value was 5.9 ± 3.1 mg/kg/min, mean euglycemic Δ13CO2 was 6.4 ± 2.1 δ‰, while median eGDR was 5.9 [4.3 - 9.8] mg/kg/min. The hyperglycemic Δ13CO2 did not correlate with the M-value, while the euglycemic Δ13CO2 and the M-value correlated strongly (r = 0.74, p < 0.001). Correlation between M-value and eGDR was more moderate (Spearman's rho = 0.63, p < 0.001). Linear regression showed an association between Δ13CO2 and M-value, adjusted for age, sex and HbA1c (adjusted R² = 0.52, B = 1.16, 95% CI 0.80 - 1.52, p < 0.001). The AUROC for Δ13CO2 to identify subjects with IR (M-value < 4.9 mg/kg/min) was 0.81 (95% CI 0.68 - 0.94, p < 0.001). The optimal cut-off for Δ13CO2 to identify subjects with IR was ≤ 5.8 δ‰. CONCLUSIONS: Under euglycemic conditions, the 13C-GBT accurately identified individuals with type 1 diabetes and concurrent IR, suggesting its potential as a valuable non-invasive index.

A new multiplex analysis of glucosylsphingosine and globotriaosylsphingosine in dried blood spots by tandem mass spectrometry.

Background: Gaucher's and Fabry's disease are two of the most common treatable lysosomal storage diseases, and have a wide spectrum of clinical symptoms. Early detection is important, because timely initiation of treatments can improve the disease status and prevent complications. However disease manifestations develop in childhood, diagnosis is delayed until adulthood partly due to the limitations of the currently used diagnostic pathway. The aim of this research is to develop and validate a multiplex assay and defining reference ranges, which do not exist at this moment, to improve and facilitate the entire diagnostic work up and enable treatment in an earlier stage of disease. Methods and findings: Biomarkers glucosylsphingosine (GlcSph) and globotriaosylsphingosine (Lyso-Gb3) were detected and quantified using LC-MS/MS on dried blood spots. We developed an improved and new extraction method that allowed to measure GlcSph and Lyso-Gb3 in a multiplex analytical platform. After validation of the method, samples of 1480 individuals with normal enzymatic activity were collected to determine age and gender-related reference ranges.Our combination method showed a good linearity, precision, accuracy and limit of quantification with lack of carry-over following the specific international CLSI guidelines. The suggested protocol is robust, efficient, sensitive, specific, comprehensive and relatively cheap in order to accelerate the diagnostic process for both lysosomal storage diseases. The samples, with normal enzymatic activity, defined statistical relevant and clinical correct reference ranges for each specific age group by gender. Conclusion: We report a multiplex LC-MS/MS method and relevant reference ranges that are appropriate for the targeted screening, diagnosis and follow-up of Fabry and Gaucher disease.

Does the Tacrolimus Trough Level Adequately Predict Drug Exposure in Patients Requiring a High Tacrolimus Dose?

Tacrolimus (Tac) has a narrow therapeutic range. Dosing is generally targeted at Tac trough levels (C 0), notwithstanding conflicting reports on the correlation between Tac C 0 and systemic exposure measured by the area-under-the-concentration-over-time curve (AUC). The Tac dose required to meet the target C 0 varies highly among patients. We hypothesized that patients requiring a relatively high Tac dose for a certain C 0 may show a higher AUC. Methods: We retrospectively analyzed data from 53 patients in which a 24-h Tac AUC24 estimation was performed at our center. Patients were divided into those taking a low (≤0.15 mg/kg) or high (>0.15 mg/kg) once-daily Tac dose. Multiple linear regression models were used to investigate if the association between C 0 and AUC24 changes according to dose level. Results: Despite the large difference in mean Tac dose between the low- and high-dose group (7 versus 17 mg/d), C 0 levels were similar. However, the mean AUC24 was substantially higher in the high-dose group (320 ± 96 h·µg/L versus 255 ± 81 h·µg/L, P < 0.001). This difference remained significant after adjusting for age and race. For a same C 0, every 0.01 mg/kg increase in Tac dose resulted in an AUC24 increase of 3.59 h·µg/L. Conclusions: This study challenges the general belief that C 0 levels are sufficiently reliable to estimate systemic drug exposure. We demonstrated that patients requiring a relatively high Tac dose to attain therapeutic C 0 levels have higher drug exposure and could therefore potentially be overdosed.

Serum concentrations of local anesthetics after unilateral interpectoral-pectoserratus plane block in breast cancer surgery: a pharmacokinetic study.

INTRODUCTION: The ultrasound-guided interpectoral-pectoserratus plane block is a fascial plane block for superficial surgery of the anterolateral chest wall. This technique involves injecting a relatively large volume of local anesthetics (typically 30 mL of 0.25%-0.50%, ie, 75-150 mg ropivacaine) underneath the major and minor pectoral muscles of the anterior thoracic wall. There is a potential risk of toxic serum concentrations of local anesthetics due to systemic absorption. METHODS: 22 patients scheduled for elective unilateral breast cancer surgery were included in this study. All surgery was performed with general anesthesia and an ultrasound-guided interpectoral-pectoserratus plane block with 2.5 mg/kg ropivacaine. Ten venous blood samples were collected at 0 (two samples) 10, 20, 30, 45, 60, 90 and 120 min and at 4 hours after performing the block. Free and total ropivacaine levels were measured at each time point. Albumin and alpha-1-acid-glycoprotein were measured to monitor shifts between the free and bound fraction of ropivacaine. RESULTS: Samples of 20 patients were analyzed. The mean dose of ropivacaine was 172.8 (22.5) mg. In 50% of the patients, the potentially toxic threshold of 0.15 µg/mL free ropivacaine concentration was exceeded. Mean peak serum concentration occurred at 20 min postinjection. CONCLUSIONS: This pharmacokinetic study demonstrated that a 2.5 mg/kg ropivacaine interpectoral-pectoserratus plane block may result in exceeding the threshold for local anesthetic systemic toxicity.

Tolerogenic Dendritic Cells Induce Apoptosis-Independent T Cell Hyporesponsiveness of SARS-CoV-2-Specific T Cells in an Antigen-Specific Manner.

Although the global pandemic caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still ongoing, there are currently no specific and highly efficient drugs for COVID-19 available, particularly in severe cases. Recent findings demonstrate that severe COVID-19 disease that requires hospitalization is associated with the hyperactivation of CD4+ and CD8+ T cell subsets. In this study, we aimed to counteract this high inflammatory state by inducing T-cell hyporesponsiveness in a SARS-CoV-2-specific manner using tolerogenic dendritic cells (tolDC). In vitro-activated SARS-CoV-2-specific T cells were isolated and stimulated with SARS-CoV-2 peptide-loaded monocyte-derived tolDC or with SARS-CoV-2 peptide-loaded conventional (conv) DC. We demonstrate a significant decrease in the number of interferon (IFN)-γ spot-forming cells when SARS-CoV-2-specific T cells were stimulated with tolDC as compared to stimulation with convDC. Importantly, this IFN-γ downmodulation in SARS-CoV-2-specific T cells was antigen-specific, since T cells retain their capacity to respond to an unrelated antigen and are not mediated by T cell deletion. Altogether, we have demonstrated that SARS-CoV-2 peptide-pulsed tolDC induces SARS-CoV-2-specific T cell hyporesponsiveness in an antigen-specific manner as compared to stimulation with SARS-CoV-2-specific convDC. These observations underline the clinical potential of tolDC to correct the immunological imbalance in the critically ill.

Therapeutic drug monitoring of fenfluramine in clinical practice: Pharmacokinetic variability and impact of concomitant antiseizure medications.

OBJECTIVE: This study was undertaken to determine the plasma concentration and pharmacokinetic variability of fenfluramine (FFA) and its main active metabolite norfenfluramine (norFFA) in relation to the prevalence of adverse effects in patients with refractory epilepsy treated with FFA. In addition, the interaction with concomitant antiseizure medications including stiripentol (STP) is studied. METHODS: Patients were recruited at our center from two open-label sources, an investigator-initiated observational study and an international multicenter extension study. Venous blood samples were collected between June 2015 and December 2020. Plasma FFA and norFFA concentrations were determined by liquid chromatography tandem spectrometric analysis. Clinical data were collected retrospectively. Intrapatient coefficient of variation was calculated for all patients with at least three samples. Interpatient variability was calculated based on the concentration to weight-adjusted dose ratio (C/D) of all patients. RESULTS: We collected 321 samples from 61 patients (49 with Dravet syndrome, seven with Lennox-Gastaut syndrome, and five with a developmental and epileptic encephalopathy). With a mean daily dose of .33 mg/kg/day (SD = ±.16), the median FFA plasma concentration was 41.4 µg/L (range = 5.1-712.5) and median norFFA concentration 28.1 µg/L (range = 2.6-149.6). The FFA plasma concentration was linearly related to the daily dose (p < .001) and norFFA levels (p < .001). The C/D of FFA increased with age (p < .001). Median FFA C/D was 428% higher (p < .001), norFFA C/D 83% lower (p < .001), and norFFA/FFA 23% lower (p < .001) in patients treated with STP comedication. Higher FFA concentration was associated with fatigue (p = .001) and somnolence (p < .001), but not anorexia (p = .0619) or reduction in seizure frequency (p = .772). Gender and other ASMs were not associated with significant variations in (nor)FFA C/D ratio. SIGNIFICANCE: Most FFA levels are in the lower range (<50 µg/L), although a high interpatient and intrapatient variability is present. In combination with STP, the dose of FFA should be reduced.

Belgian rare diseases plan in clinical pathology: identification of key biochemical diagnostic tests and establishment of reference laboratories and financing conditions.

BACKGROUND: One objective of the Belgian Rare Diseases plan is to improve patients' management using phenotypic tests and, more specifically, the access to those tests by identifying the biochemical analyses used for rare diseases, developing new financing conditions and establishing reference laboratories. METHODS: A feasibility study was performed from May 2015 until August 2016 in order to select the financeable biochemical analyses, and, among them, those that should be performed by reference laboratories. This selection was based on an inventory of analyses used for rare diseases and a survey addressed to the Belgian laboratories of clinical pathology (investigating the annual analytical costs, volumes, turnaround times and the tests unavailable in Belgium and outsourced abroad). A proposal of financeable analyses, financing modalities, reference laboratories' scope and budget estimation was developed and submitted to the Belgian healthcare authorities. After its approval in December 2016, the implementation phase took place from January 2017 until December 2019. RESULTS: In 2019, new reimbursement conditions have been published for 46 analyses and eighteen reference laboratories have been recognized. Collaborations have also been developed with 5 foreign laboratories in order to organize the outsourcing and financing of 9 analyses unavailable in Belgium. CONCLUSIONS: In the context of clinical pathology and rare diseases, this initiative enabled to identify unreimbursed analyses and to meet the most crucial financial needs. It also contributed to improve patients' management by establishing Belgian reference laboratories and foreign referral laboratories for highly-specific analyses and a permanent surveillance, quality and financing framework for those tests.

Non-Alcoholic Steatohepatitis Decreases Microsomal Liver Function in the Absence of Fibrosis.

The incidence of non-alcoholic fatty liver disease (NAFLD) is rising across the globe, with the presence of steatohepatitis leading to a more aggressive clinical course. Currently, the diagnosis of non-alcoholic steatohepatitis (NASH) is based on histology, though with the high prevalence of NAFLD, a non-invasive method is needed. The 13C-aminopyrine breath test (ABT) evaluates the microsomal liver function and could be a potential candidate. We aimed to evaluate a potential change in liver function in NASH patients and to evaluate the diagnostic power of ABT to detect NASH. We performed a retrospective analysis on patients suspected of NAFLD who underwent a liver biopsy and ABT. 440 patients were included. ABT did not decrease in patients with isolated liver steatosis but decreased significantly in the presence of NASH without fibrosis and decreased even further with the presence of significant fibrosis. The predictive power of ABT as a single test for NASH was low but improved in combination with ALT and ultrasonographic steatosis. We conclude that microsomal liver function of patients with NASH is significantly decreased, even in the absence of fibrosis. The ABT is thus a valuable tool in assessing the presence of NASH; and could be used as a supplementary diagnostic tool in clinical practice.

Partial Inhibition of Glycolysis Reduces Atherogenesis Independent of Intraplaque Neovascularization in Mice.

OBJECTIVE: Intraplaque neovascularization is an important feature of unstable human atherosclerotic plaques. However, its impact on plaque formation and stability is poorly studied. Because proliferating endothelial cells generate up to 85% of their ATP from glycolysis, we investigated whether pharmacological inhibition of glycolytic flux by the small-molecule 3PO (3-[3-pyridinyl]-1-[4-pyridinyl]-2-propen-1-one) could have beneficial effects on plaque formation and composition. Approach and Results: ApoE-/- (apolipoprotein E deficient) mice treated with 3PO (50 µg/g, ip; 4×/wk, 4 weeks) showed a metabolic switch toward ketone body formation. Treatment of ApoE-/-Fbn1C1039G+/- mice with 3PO (50 µg/g, ip) either after 4 (preventive, twice/wk, 10 weeks) or 16 weeks of Western diet (curative, 4×/wk, 4 weeks) inhibited intraplaque neovascularization by 50% and 38%, respectively. Plaque formation was significantly reduced in all 3PO-treated animals. This effect was independent of intraplaque neovascularization. In vitro experiments showed that 3PO favors an anti-inflammatory M2 macrophage subtype and suppresses an M1 proinflammatory phenotype. Moreover, 3PO induced autophagy, which in turn impaired NF-κB (nuclear factor-kappa B) signaling and inhibited TNF-α (tumor necrosis factor-alpha)-mediated VCAM-1 (vascular cell adhesion molecule-1) and ICAM-1 (intercellular adhesion molecule-1) upregulation. Consistently, a preventive 3PO regimen reduced endothelial VCAM-1 expression in vivo. Furthermore, 3PO improved cardiac function in ApoE-/-Fbn1C1039G+/- mice after 10 weeks of treatment. CONCLUSIONS: Partial inhibition of glycolysis restrained intraplaque angiogenesis without affecting plaque composition. However, less plaques were formed, which was accompanied by downregulation of endothelial adhesion molecules-an event that depends on autophagy induction. Inhibition of coronary plaque formation by 3PO resulted in an overall improved cardiac function.

Analytical and clinical performance of three hand-held point-of-care creatinine analyzers for renal function measurements prior to contrast-enhanced imaging.

BACKGROUND: As iodine-based contrast can cause deterioration of renal function in patients with impaired kidney function, guidelines advise to measure creatinine and calculate estimated glomerular filtration (eGFR) prior to administration. Point-of-care (POC) devices seem an attractive alternative to central laboratory testing but uncertainty regarding analytical and clinical comparability remains. METHODS: This study compared three POC devices, i-STAT (Abbott), StatSensor (Nova) and epoc (Siemens) with a central laboratory method (enzymatic creatinine, Siemens Vista 1500 platform). 120 patients were included and underwent simultaneous finger prick capillary blood analysis on the StatSensor and heparine whole blood analysis on StatSensor, i-STAT and epoc. RESULTS: All POC devices generated results which showed considerable variability around the creatinine value of the reference standard, with StatSensor having the widest (-1,12-1,11 mg/dL) and epoc the tightest (-0,49-0,49 mg/dL) 95% limits of agreement. I-STAT showed the highest clinical concordance with the reference standard (Kappa: 0,94) and had the smallest average analytical error (6%) for creatinine and eGFR compared to the reference standard, meeting the predefined criteria of 8,87% and 10%, respectively. Epoc only met criteria for eGFR. StatSensor did not meet any of the criteria. CONCLUSIONS: I-STAT and epoc were, analytically and clinically, the most performant POC devices included in this study but showed to be less user-friendly. StatSensor did not meet any of the error criteria, neither for creatinine nor for eGFR measurements, and gave more clinical major classification errors. However, it proved to be more user-friendly compared to the other POC devices.

Evaluation of vilazodone for the treatment of depressive and anxiety disorders.

INTRODUCTION: Major Depressive Disorder (MDD) and General Anxiety Disorder (GAD) significantly contribute to the global burden of disease. Vilazodone, a combined serotonin reuptake inhibitor and 5-HT1A partial agonist, is an approved therapy for the treatment of MDD and which has been further investigated for GAD. Areas covered: This article covers the pharmacokinetics and pharmacodynamics of vilazodone and provides an evaluation of the clinical usefulness of vilazodone for the treatment of MDD and anxiety disorders. A literature search was performed using PubMed/MEDLINE, Web of Science and the Cochrane Library. Expert opinion: Studies have shown that vilazodone is significantly superior to placebo. However, vilazodone cannot as yet be recommended as a first-line treatment option for MDD as it is unclear whether the drug's dual mechanism of action provides greater efficacy than prevailing treatment options. Moreover, more phase IV studies are needed to establish its efficacy and long-term safety in larger and more diverse populations. Although vilazodone may have an additional advantage for the treatment of anxiety symptoms in MDD, here also additional studies are required to confirm its efficacy over and above SSRI alternatives and other antidepressant treatments. Therefore, presently, vilazodone should be considered as a second- or third-line treatment option for MDD and GAD.

Pharmacokinetic evaluation of the aripiprazole (once-monthly) injection for the treatment of bipolar disorder.

INTRODUCTION: Bipolar disorder is a severe, chronic psychiatric disorder with a need for long-term treatment. Patient nonadherence is frequent and poses a major problem in maintenance therapy. Aripiprazole once-monthly long-acting injectable (AOM LAI) is a recently US Food and Drug Administration-approved treatment option for maintenance therapy that could be of great value. Areas covered: This paper reviews the pharmacokinetic, efficacy and safety data for AOM LAI in bipolar disorder. Expert opinion: AOM LAI is a safe and efficacious treatment option in the maintenance therapy of bipolar I disorder. However, further research is still needed to determine the position of AOM LAI relative to other available treatment options.

Pharmacotherapy and nutritional supplements for seasonal affective disorders: a systematic review.

INTRODUCTION: A seasonal affective disorder (SAD) is a subtype of unipolar and bipolar major depressive disorders. It is characterized by its annual recurrence of depressive episodes at a particular season, mostly seen in winter and is responsible for 10-20% of the prevalence of major depressive disorders. Some pathophysiological hypotheses, such as the phase delay and the monoamine depletion hypotheses, have been postulated but the exact cause has not been fully unraveled yet. Studies on treatment for SAD in the last decade are lacking. To tackle this chronic disease, attention needs to be drawn to the gaps in this research field. AREAS COVERED: In this systematic review, the authors give a broad overview of the pharmacological therapy available for SAD. Also, nutritional substances fitting well with the postulated hypotheses are reviewed for the treatment and prevention of SAD. There is a specific focus on the quality of the currently performed studies. EXPERT OPINION: Light therapy and fluoxetine are the only proven and effective acute treatment options for SAD, while bupropion is the only registered drug for prevention of SAD. This area of research is in dire need of valid large-scale and sufficiently reproducible randomized control trials.

What can we learn from monitoring PCBs in the European eel? A Belgian experience.

Between 2000 and 2007 pooled muscle tissue samples of the European eel (Anguilla anguilla) from 48 sites in Flanders (Belgium) were analysed for 30 polychlorinated biphenyl (PCB) congeners. There was a large variation between individual sites (range 11-7752 ng/g wet weight (ww) for the sum of the ICES 7 PCBs), eels from the River Meuse basin (mean 1545 ng/g ww) being considerably more polluted than those from the River Scheldt (615) and IJzer (61) basins. Overall, PCB 153, PCB 138 and PCB 180 were the most prominent congeners, however PCB patterns varied between the monitored locations. Analysis of the weight percentage of congeners demonstrates obvious differences in PCB composition between sites, indicating differential sources of pollution. Due to the variation in patterns, atmospheric fallout does not seem to be the main source of the PCB spread, but instead both local and upstream sources linked to industrial activities seem to be the main cause for PCB presence in Flanders. Considering the levels of the Sum 7 PCBs, eels are not compliant with the Belgian legal limits for consumption (75 ng/g ww) in 71% of the sites. Regular consumption of eels from polluted sites leads to a considerable excess of the WHO Acceptable Daily Intake value. Consumption of wild eels should by all means be prevented, as it presents risks for human health, especially for local anglers consuming their catch.

Obesity and persistent organic pollutants: possible obesogenic effect of organochlorine pesticides and polychlorinated biphenyls.

Persistent organic pollutants (POPs) are endocrine-disrupting chemicals associated with the development of the metabolic syndrome and type 2 diabetes. In humans, little is known about their role in the potential origin of obesity. This study aims to assess the associations between serum levels of POPs and the prevalence of obesity in a cohort of obese and lean adult men and women. POP serum samples were investigated cross-sectionally in 98 obese and 47 lean participants, aged ≥18 years. Serum samples were analyzed for the presence of polychlorinated biphenyl (PCB) congeners 153, 138, 180, and 170 and for the organochlorine pesticides, dichloro-diphenyl-dichloroethylene (pp-DDE), and ß-hexachlorocyclohexane (ßHCH). We established a significant negative correlation between BMI, waist, fat mass percentage, total and subcutaneous abdominal adipose tissue, and serum levels of PCB 153, 180, 170, and the sumPCBs. For ßHCH, we demonstrated a positive correlation with BMI, waist, fat mass percentage, and total and subcutaneous abdominal adipose tissue. PCBs 180, 170, and the sum of PCBs correlated significantly negative with homeostasis model assessment for insulin resistance (HOMA(IR)). ßHCH correlated significantly positively with HOMA(IR). A strong correlation was established between all POP serum levels and age. We established a positive relationship between high serum levels of ßHCH and BMI and HOMA(IR), whereas serum PCB levels were inversely correlated with BMI and HOMA(IR). Combined, these results suggest that the diabetogenic effect of low-dose exposure to POPs might be more complicated than a simple obesogenic effect.

Brominated flame retardants and perfluorinated compounds in indoor dust from homes and offices in Flanders, Belgium.

The increasing time spent indoors combined with the abundant usage of diverse indoor chemicals led to concerns involving the impact of these compounds on human health. The current study focused on two groups of important indoor contaminants i.e. Brominated flame retardants (BFRs) and Perfluorinated compounds (PFCs). Concentrations of both compound classes have been measured in Flemish indoor dust samples from homes and offices. ΣPolybrominated diphenyl ethers (PBDEs) (BDE 47, 99, 100, 154, 153, 197, 196 and 203) and BDE 209 in homes ranged between 4-1214 ng g(-1)dw (median 35) and <5-5295 ng g(-1)dw (median 313), respectively. Hexabromocyclododecane (ΣHBCD) levels ranged from 5 to 4,2692 ng g(-1)dw (median 130), with α-HBCD being the major isomer (mean 59%). In addition, tetrabromobisphenol A (TBBPA) ranged between <3 and 419 ng g(-1)dw (median 12). For all BFRs, median levels in office dust were up to an order of magnitude higher than in home dust. ΣPFCs (sum of perfluorobutane sulfonate (PFBS), perfluorohexane sulfonate (PFHxS), perfluorooctane sulfonic acid (PFOS), perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA)) concentrations in homes ranged from 0.2 to 336 ng g(-1) (median 3.0 ng g(-1)). Levels in office dust were higher (p<0.01) than in house dust with ΣPFCs ranging between 2.2 and 647 ng g(-1) (median 10 ng g(-1)) and median (PFOA) and perfluorooctane sulfonate values of 2.9 and 2.2 ng g(-1), respectively. The congener pattern was dominated by PFOA, followed by PFOS. Calculated human exposure was below the reference dose values set by the US-EPA for BDE 209, HBCD and below the provisional tolerable daily intakes proposed by European Food Safety Authority for PFOS and PFOA.