Lower iodine storage in the placenta is associated with gestational diabetes mellitus.

BACKGROUND: The micronutrient iodine is essential for a healthy intrauterine environment and is required for optimal fetal growth and neurodevelopment. Evidence linking urinary iodine concentrations, which mainly reflects short-term iodine intake, to gestational diabetes mellitus (GDM) is inconclusive. Although the placental concentrations would better reflect the long-term gestational iodine status, no studies to date have investigated the association between the placental iodine load and the risk at GDM. Moreover, evidence is lacking whether placental iodine could play a role in biomarkers of insulin resistance and ß-cell activity. METHODS: We assessed the incidence of GDM between weeks 24 and 28 of gestation for 471 mother-neonate pairs from the ENVIRONAGE birth cohort. In placentas, we determined the iodine concentrations. In maternal and cord blood, we measured the insulin concentrations, the Homeostasis Model Assessment (HOMA) for insulin resistance (IR) index, and ß-cell activity. Logistic regression was used to estimate the odds ratios (OR) of GDM, and the population attributable factor (PAF) was calculated. Generalized linear models estimated the changes in insulin, HOMA-IR, and ß-cell activity for a 5 µg/kg increase in placental iodine. RESULTS: Higher placental iodine concentrations decreased the risk at GDM (OR = 0.82; 95%CI 0.72 to 0.93; p = 0.003). According to the PAF, 54.2% (95%CI 11.4 to 82.3%; p = 0.0006) of the GDM cases could be prevented if the mothers of the lowest tertile of placental iodine would have placental iodine levels as those belonging to the highest tertile. In cord blood, the plasma insulin concentration was inversely associated with the placental iodine load (ß = - 4.8%; 95%CI - 8.9 to - 0.6%; p = 0.026). CONCLUSIONS: Higher concentrations of placental iodine are linked with a lower incidence of GDM. Moreover, a lower placental iodine load is associated with an altered plasma insulin concentration, HOMA-IR index, and ß-cell activity. These findings postulate that a mild-to-moderate iodine deficiency could be linked with subclinical and early-onset alterations in the normal insulin homeostasis in healthy pregnant women. Nevertheless, the functional link between gestational iodine status and GDM warrants further research.

Prenatal particulate air pollution exposure and cord blood homocysteine in newborns: Results from the ENVIRONAGE birth cohort.

INTRODUCTION: Particulate air pollution is probably causally related to increased risk of cardiovascular disease. Plasma homocysteine is an established cardiovascular disease risk factor. Recent studies show that exposure to particulate air pollution is associated with plasma homocysteine levels in adults but no studies on the association between prenatal air pollution and neonatal homocysteine levels exist. METHODS: In 609 newborns of the ENVIRONAGE (ENVIRonmental influence ON early AGEing) birth cohort, we investigated the association between prenatal particulate matter exposure with a diameter ≤ 2.5 µm (PM2.5) and cord plasma homocysteine levels, and in a subset (n = 490) we studied the interaction with 11 single nucleotide polymorphism (SNPs) in oxidative stress-related genes (CAT, COMT, GSTP1, SOD2, NQO1 and HFE), through multiple linear regression. PM2.5 levels were obtained using a high resolution spatial temporal interpolation method. Homocysteine levels were measured by the homocysteine enzymatic assay on a Roche/Hitachi cobas c system. SNPs were assessed on the Biotrove OpenArray SNP genotyping platform. RESULTS: In multivariable-adjusted models, cord plasma homocysteine levels were 8.1% higher (95% CI: 1.9 to 14.3%; p = 0.01) for each 5 µg/m³ increment in average PM2.5 exposure during the entire pregnancy. With regard to pregnancy trimesters, there was only an association in the 2nd trimester: 3.6% (95% CI: 0.9% to 6.4%; p = 0.01). The positive association between PM2.5 in and homocysteine was (borderline) statistically significantly modified by genetic variants in MnSOD (p interaction = 0.02), GSTP1 (p interaction = 0.07) and the sum score of the 3 studied SNPs in the CAT gene (p interaction=0.09), suggesting oxidative stress as an underlying mechanism of action. CONCLUSIONS: Exposure to particulate air pollution in utero is associated with higher cord blood homocysteine levels, possibly through generating oxidative stress. Increased air pollution-induced homocysteine levels in early life might predispose for cardiovascular and other diseases later in life.

Plasma Volume Is Normal but Heterogeneously Distributed, and True Anemia Is Highly Prevalent in Patients With Stable Heart Failure.

BACKGROUND: Intravascular volume overload and depletion as well as anemia are associated with increased hospital admissions and mortality in patients with heart failure. This study aimed to accurately measure plasma volume and red cell mass (RCM) in stable patients with chronic heart failure with reduced ejection fraction (HFrEF) and gain more insight into plasma volume regulation and anemia in stable conditions of HFrEF. METHODS AND RESULTS: Plasma volume and RCM measurement based on 99Tc-labeled red blood cells, venous blood sample,s and clinical parameters were obtained in 24 stable HFrEF patients under optimal medical therapy. Measured plasma volume values were compared with predicted values based on body surface area. Plasma volume was on average normal (99.98% of predicted) but heterogeneously distributed (variations of 81%-133%). Neurohumoral activation and medication use were not associated with plasma volume status. Furthermore, anemia based on actual measurement of RCM was present in up to 75% of subjects, but rarely hemodilutional. CONCLUSIONS: In stable chronic HFrEF patients under optimal medical therapy, plasma volume is overall normal but heterogeneously distributed. Anticipated factors such as neurohumoral activation and heart failure medication were not associated with plasma volume. Furthermore, anemia is more common than as assessed by hemoglobin.

Determinants and impact of the natriuretic response to diuretic therapy in heart failure with reduced ejection fraction and volume overload.

OBJECTIVE: The objective of this study was to investigate determinants of the natriuretic response to diuretics in decompensated heart failure (HF) and the relationship with decongestion, neurohumoral activation and clinical outcome in the contemporary era of HF management. METHODS AND RESULTS: In this prospective, single-centre cohort study, consecutive patients with decompensated HF (n = 54) and left ventricular ejection fraction 45% received protocol-driven diuretic therapy until complete disappearance of congestion signs. Urine was collected during three consecutive 24-h intervals. Natriuretic response was defined as absolute natriuresis (mmol) per mg of intravenous bumetanide administered. Natriuresis was 146 mmol (76-206 mmol), 74 mmol (37-167 mmol) and 74 mmol (53-134 mmol) per mg intravenous bumetanide administered during the first, second and third 24-h interval, respectively. Diastolic blood pressure (beta = 23.048 +/- 10.788; P-value = 0.036), plasma aldosterone (beta = -25.722?11.560; P-value=0.029), and combination therapy with acetazolamide (beta = 103.241 +/- 40.962; P-value = 0.014) were independent predictors of the natriuretic response. Patients with a stronger natriuretic response demonstrated more pronounced decreases in plasma NT-proBNP levels (P-value = 0.025), while a weaker response was associated with higher peak plasma aldosterone levels (P-value = 0.013) and plasma renin activity (P-value = 0.033). Natriuresis per loop diuretic dose predicted freedom from all-cause mortality or HF readmissions, independently of baseline renal function (HR 0.40, 95% CI 0.16-0.98; P-value = 0.045). CONCLUSIONS: More effective natriuresis in decompensated HF patients with reduced ejection fraction and volume overload is associated with better decongestion, less neurohumoral activation and predicts favourable clinical outcome independently from renal function per se. Acetazolamide warrants further evaluation in large prospective trials to increase the natriuretic response to loop diuretics.

Prognostic value of glomerular filtration changes versus natriuretic response in decompensated heart failure with reduced ejection.

BACKGROUND: Glomerular filtration rate (GFR) and natriuretic response to diuretics represent important treatment targets in acute decompensated heart failure (ADHF). METHODS AND RESULTS: Consecutive ADHF patients (n = 50) with ejection fraction ≤ 45% and clinical signs of volume overload received protocol-driven decongestive therapy. Serum creatinine (Cr), cystatin C (CysC), and ß-trace protein (ßTP) were measured on admission and three subsequent days of treatment. Worsening renal function (WRF) was defined as a ≥ 0.3 increase in absolute biomarker levels or ≥ 20% decrease in estimated GFR. Consecutive 24-hour urinary collections were simultaneously performed to measure Cr clearance and natriuresis. Serum Cr, CysC, and ßTP were strongly correlated at admission (ρ = 0.788-0.909) and during decongestive treatment (ρ = 0.884-888). Moreover, derived GFR estimates correlated well with Cr clearance (ρ = 0.820-0.908). Nevertheless, WRF incidence differed markedly according to Cr- (26%-30%), CysC- (46%-54%), or ßTP-based definitions (31%-48%). WRF by any definition was not associated with all-cause mortality or ADHF readmission, in contrast to stronger natriuresis per loop diuretic dose [hazard ratio 0.20 (95% confidence interval 0.06-0.64); P = .007]. CONCLUSIONS: Serial measurements of CysC/ßTP, compared with serum Cr, more frequently indicate WRF during decongestive treatment in ADHF. However, adverse clinical outcome in such patients might be better predicted by the natriuretic response to diuretic therapy.

Newborn glomerular function and gestational particulate air pollution.

BACKGROUND: Nephron number variability may hold significance in the Developmental Origins of Health and Disease hypothesis. We explore the impact of gestational particulate pollution exposure on cord blood cystatin C, a marker for glomerular function, as an indicator for glomerular health at birth. METHODS: From February 2010 onwards, the ENVIRONAGE cohort includes over 2200 mothers giving birth at the East-Limburg hospital in Genk, Belgium. Mothers without planned caesarean section who are able to fill out a Dutch questionnaire are eligible. Here, we evaluated cord blood cystatin C levels from 1484 mother-child pairs participating in the ENVIRONAGE cohort. We employed multiple linear regression models and distributed lag models to assess the association between cord blood cystatin C and gestational particulate air pollution exposure. FINDINGS: Average ± SD levels of cord blood cystatin C levels amounted to 2.16 ± 0.35 mg/L. Adjusting for covariates, every 0.5 µg/m³ and 5 µg/m³ increment in gestational exposure to black carbon (BC) and fine particulate matter (PM2.5) corresponded to increases of 0.04 mg/L (95% CI 0.01-0.07) and 0.07 mg/L (95% CI 0.03-0.11) in cord blood cystatin C levels (p < 0.01), respectively. Third-trimester exposure showed similar associations, with a 0.04 mg/L (95% CI 0.00-0.08) and 0.06 mg/L (95% CI 0.04-0.09) increase for BC and PM2.5 (p < 0.02). No significant associations were observed when considering only the first and second trimester exposure. INTERPRETATION: Our findings indicate that particulate air pollution during the entire pregnancy, with the strongest effect sizes from week 27 onwards, may affect newborn kidney function, with potential long-term implications for later health. FUNDING: Special Research Fund (Bijzonder Onderzoeksfonds, BOF), Flemish Scientific Research Fund (Fonds Wetenschappelijk Onderzoek, FWO), and Methusalem.

Establishment of reference values for novel urinary biomarkers for renal damage in the healthy population: are age and gender an issue?

BACKGROUND: Recently, a lot of research has focused on the discovery of novel renal biomarkers. Among others, the urinary kidney injury molecule 1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) have been proven to be promising biomarkers in a wide variety of renal pathologies. However, little is known about the normal concentrations in urine of healthy subjects. Therefore, the goal of our study is to establish reference values for urinary KIM-1, NGAL, N-acetyl-ß-D-glucosamidase (NAG), and cystatin C in a healthy population, taking into account possible effects of age and gender. METHODS: We collected urine samples from 338 healthy, nonsmoking subjects between 0 and 95 years old. Subjects with elevated α1-microglobulin values were excluded. Next to the urinary concentrations of KIM-1, NGAL, NAG, and cystatin C, we measured urinary creatinine and specific gravity to correct for urinary dilution. The possible effect of age and gender on the four urinary biomarkers was investigated, and the reference values were established. RESULTS: For the absolute urinary concentrations of the biomarkers, age had a significant effect on all the biomarkers, except for cystatin C, whereas gender significantly affected all four of them, except for NAG. The normalization of biomarkers for creatinine and specific gravity had an effect on the correlation between the biomarkers on one hand and age and gender on the other. CONCLUSIONS: In conclusion, age and gender had different effects on KIM-1, NGAL, NAG, and cystatin C. Based on this knowledge, age- and gender-specific reference values for KIM-1, NGAL, NAG, and cystatin C were established.

Ecstasy intoxication as an unusual cause of epileptic seizures in young children.

In light of the widespread use of ecstasy, it is surprising that only few cases of intoxicated young children have been reported. Patients almost invariably present with convulsions accompanied by sympathetic signs and symptoms such as hyperthermia. Two new cases of toddlers intoxicated with ecstasy are described. The first patient, a 19-month-old boy, presented with convulsions but no sympathetic signs. The pediatrician's suspicion was raised because of the absence of a postictal state. The second patient, a 20-month-old girl, had a more typical presentation with convulsions and hyperthermia. Her story illustrates the fact that immunoassays for toxicological screening can easily miss traces of additional illicit drugs present in the urine such as cocaine. The presence of other illicit drugs provides clues to the child's risky environment and should lead to further investigation. Finally, we review the available literature on ecstasy intoxication to summarize the key presenting manifestations.

Placental DNA hypomethylation in association with particulate air pollution in early life.

BACKGROUND: There is evidence that altered DNA methylation is an important epigenetic mechanism in prenatal programming and that developmental periods are sensitive to environmental stressors. We hypothesized that exposure to fine particles (PM2.5) during pregnancy could influence DNA methylation patterns of the placenta. METHODS: In the ENVIRONAGE birth cohort, levels of 5'-methyl-deoxycytidine (5-mdC) and deoxycytidine (dC) were quantified in placental DNA from 240 newborns. Multiple regression models were used to study placental global DNA methylation and in utero exposure to PM2.5 over various time windows during pregnancy. RESULTS: PM2.5 exposure during pregnancy averaged (25th-75th percentile) 17.4 (15.4-19.3) µg/m3. Placental global DNA methylation was inversely associated with PM2.5 exposures during whole pregnancy and relatively decreased by 2.19% (95% confidence interval [CI]: -3.65, -0.73%, p = 0.004) for each 5 µg/m3 increase in exposure to PM2.5. In a multi-lag model in which all three trimester exposures were fitted as independent variables in the same regression model, only exposure to PM2.5 during trimester 1 was significantly associated with lower global DNA methylation (-2.13% per 5 µg/m3 increase, 95% CI: -3.71, -0.54%, p = 0.009). When we analyzed shorter time windows of exposure within trimester 1, we observed a lower placental DNA methylation at birth during all implantation stages but exposure during the implantation range (6-21d) was strongest associated (-1.08% per 5 µg/m3 increase, 95% CI: -1.80, -0.36%, p = 0.004). CONCLUSIONS: We observed a lower degree of placental global DNA methylation in association with exposure to particulate air pollution in early pregnancy, including the critical stages of implantation. Future studies should elucidate genome-wide and gene-specific methylation patterns in placental tissue that could link particulate exposure during in utero life and early epigenetic modulations.

The effect of spinal versus general anaesthesia on perioperative muscle weakness in patients having bilateral total hip arthroplasty: a single center randomized clinical trial.

BACKGROUND: Perioperative neuro-endocrine stress response may contribute to acquired muscle weakness. Regional anaesthesia has been reported to improve the outcome of patients having total hip arthroplasty. In this study, it was hypothesized that spinal anaesthesia (SA) decreases the perioperative neuro-endocrine stress response and perioperatively acquired muscle weakness (PAMW), as compared to general anaesthesia (GA). METHODS: Fifty subjects undergoing bilateral total hip arthroplasty (THA) were randomly allocated to receive a standardized SA (n = 25) or GA (n = 25). Handgrip strength was assessed preoperatively, on the first postoperative day (primary endpoint) and on day 7 and 28. Respiratory muscle strength was measured by maximal inspiratory pressure (MIP). Stress response was assessed by measuring levels of Adrenocorticotropic hormone (ACTH), cortisol and interleukin-6 (IL-6). RESULTS: Handgrip strength postoperatively (day 1) decreased by 5.4 ± 15.9% in the SA group, versus 15.2 ± 11.7% in the GA group (p = 0.02). The handgrip strength returned to baseline at day 7 and did not differ between groups at day 28. MIP increased postoperatively in patients randomized to SA by 11.7 ± 48.3%, whereas it decreased in GA by 12.2 ± 19.9% (p = 0.04). On day 7, MIP increased in both groups, but more in the SA (49.0 ± 47.8%) than in the GA group (14.2 ± 32.1%) (p = 0.006). Postoperatively, the levels of ACTH, cortisol and IL-6 increased in the GA, but not in the SA group (p < 0.004). CONCLUSION: In patients having bilateral THA, SA preserved the postoperative respiratory and peripheral muscle strength and attenuated the neuro-endocrine and inflammatory responses. TRIAL REGISTRATION: clinicaltrials.gov NCT03600454.

Mixed-methods evaluation of a multifaceted heart failure intervention in general practice: the OSCAR-HF pilot study.

AIMS: Heart failure (HF) is an important health problem for which multidisciplinary care is recommended, yet few studies involve primary care practitioners in the multidisciplinary management of HF. We set up a multifaceted prospective observational trial, OSCAR-HF, piloting audit and feedback, natriuretic peptide testing at the point of care, and the assistance of a specialist HF nurse in primary care. The aim was to optimize HF care in general practice. METHODS AND RESULTS: This is an analysis at 6 month follow-up of the study interventions of the OSCAR-HF pilot study, a nonrandomized, noncontrolled prospective observational trial conducted in eight Belgian general practices [51 general practitioners (GPs)]. Patients who were assessed by their GP to have HF constituted the OSCAR-HF study population. We used descriptive statistics and mixed-effects modelling for the quantitative analysis and thematic analysis of the focus group interviews. There was a 10.2% increase in the registered HF population after 6 months of follow-up (n = 593) compared with baseline (n = 538) and a 27% increase in objectified HF diagnoses (baseline n = 359 to 456 at T6 M). Natriuretic peptide testing (with or without referral) accounted for 54% (n = 60/111) of the newly registered HF diagnoses. There was no difference in the proportion of patients with HF with reduced ejection fraction who received their target dosage of renin-angiotensin-aldosterone system inhibitors or beta-blockers at 6 months compared with baseline (P = 0.9). Patients who received an HF nurse intervention (n = 53) had significantly worse quality of life at baseline [difference in Minnesota Living with Heart Failure Questionnaire (MLHFQ) score 9.2 points; 95% confidence interval (CI) 4.0, 14] and had a significantly greater improvement in quality-of-life scores at the 6 month follow-up [change in MLHFQ score -9.8 points; 95% CI -15, -4.5] than patients without an HF nurse intervention. GPs found audit and feedback valuable but time intensive. Natriuretic peptides were useful, but the point-of-care test was impractical, and the assistance of an HF nurse was a useful addition to routine HF care. CONCLUSIONS: The use of audit and feedback combined with natriuretic peptide testing was a successful strategy to increase the number of registered and objectified HF diagnoses at 6 months. GPs and HF nurses selected patients with worse quality-of-life scores at baseline for the HF nurse intervention, which led to a significantly greater improvement in quality-of-life scores at the 6 month follow-up compared with patients without an HF nurse intervention. The interventions were deemed feasible and useful by the participating GPs with some specific remarks that can be used for optimization. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02905786), registered on 14 September 2016 at https://clinicaltrials.gov/.

Comprehensive antibody and cytokine profiling in hospitalized COVID-19 patients in relation to clinical outcomes in a large Belgian cohort.

The immune response in patients with Coronavirus Disease 2019 (COVID-19) is highly variable and is linked to disease severity and mortality. However, antibody and cytokine responses in the early disease stage and their association with disease course and outcome are still not completely understood. In this large, multi-centre cohort study, blood samples of 434 Belgian COVID-19 hospitalized patients with different disease severities (ranging from asymptomatic/mild to critically ill) from the first wave of the COVID-19 pandemic were obtained. Baseline antibody and cytokine responses were characterized and associations with several clinical outcome parameters were determined. Anti-spike immunoglobulin (Ig)G and IgM levels were elevated in patients with a more severe disease course. This increased baseline antibody response however was associated with decreased odds for hospital mortality. Levels of the pro-inflammatory cytokines IL-6, IP-10 and IL-8, the anti-inflammatory cytokine IL-10 and the antiviral cytokines IFN-α, IFN-ß and IFN-λ1 were increased with disease severity. Remarkably, we found significantly lower levels of IFN-λ2,3 in critically ill patients compared to patients of the moderate and severe disease category. Finally, levels of IL-8, IL-6, IP-10, IL-10, IFN-α, IFN-ß, IFN-γ and IFN-λ1 at baseline were positively associated with mortality, whereas higher IFN-λ2,3 levels were negatively associated with mortality.

A sensitive quantitative test strip based point-of-care albuminuria screening assay.

BACKGROUND: Chronic kidney disease is a major health problem and the global guidelines require screening of albuminuria. Therefore, affordable and sensitive albuminuria screening tests are needed. We explored the potential of urine strips, generally reported in the ordinal scale, measured on an automatic strip reader for reporting quantitative and sensitive albumin results. METHODS: We compared reflectance data of Combur-Test® strips obtained from the Cobas U411 reader (Roche) with albuminuria data from a nephelometer BNII (Siemens) and with protein concentrations from the pyrogallol red method (Modular P, Roche) for 389/328 non-pathologic and pathologic urine samples, respectively. RESULTS: Imprecision of the reflectance signal of the Cobas U411 was measured with commercial control material (Bio-Rad). Inter-run coefficients of variations (CVs) for reflectance for levels 1 and 2 were 1.7%/4.9%, respectively, and intra-run CVs were 1.8%/4.2%, respectively. Good agreement was obtained between the albumin concentration of the BNII and the protein strip reflectance data (n=389): Y (10,000/protein reflectance, 1/%)=160+0.132·X (albuminuria BNII, mg/L)-0.0000111·X2 (albuminuria BNII, mg/L); r2=0.921. Lower agreement was found between the protein assay (n=328) and the reflectance (r2=0.831). A calibration curve was made between 11.5 mg/L and 121.5 mg/L. The limit of blank (LOB) was 44.7 mg/L. CONCLUSIONS: The present study demonstrates that reflectance data generated by a test strip reader allows for quantitative analysis of albumin. Although the lower limit of the microalbumin range (30 mg/L) cannot be achieved with the dye-binding method, the results are satisfactory for screening purposes.

Machine learning optimization of an electronic health record audit for heart failure in primary care.

AIMS: The diagnosis of heart failure (HF) is an important problem in primary care. We previously demonstrated a 74% increase in registered HF diagnoses in primary care electronic health records (EHRs) following an extended audit procedure. What remains unclear is the accuracy of registered HF pre-audit and which EHR variables are most important in the extended audit strategy. This study aims to describe the diagnostic HF classification sequence at different stages, assess general practitioner (GP) HF misclassification, and test the predictive performance of an optimized audit. METHODS AND RESULTS: This is a secondary analysis of the OSCAR-HF study, a prospective observational trial including 51 participating GPs. OSCAR used an extended audit based on typical HF risk factors, signs, symptoms, and medications in GPs' EHR. This resulted in a list of possible HF patients, which participating GPs had to classify as HF or non-HF. We compared registered HF diagnoses before and after GPs' assessment. For our analysis of audit performance, we used GPs' assessment of HF as primary outcome and audit queries as dichotomous predictor variables for a gradient boosted machine (GBM) decision tree algorithm and logistic regression model. Of the 18 011 patients eligible for the audit intervention, 4678 (26.0%) were identified as possible HF patients and submitted for GPs' assessment in the audit stage. There were 310 patients with registered HF before GP assessment, of whom 146 (47.1%) were judged not to have HF by their GP (over-registration). There were 538 patients with registered HF after GP assessment, of whom 374 (69.5%) did not have registered HF before GP assessment (under-registration). The GBM and logistic regression model had a comparable predictive performance (area under the curve of 0.70 [95% confidence interval 0.65-0.77] and 0.69 [95% confidence interval 0.64-0.75], respectively). This was not significantly impacted by reducing the set of predictor variables to the 10 most important variables identified in the GBM model (free-text and coded cardiomyopathy, ischaemic heart disease and atrial fibrillation, digoxin, mineralocorticoid receptor antagonists, and combinations of renin-angiotensin system inhibitors and beta-blockers with diuretics). This optimized query set was enough to identify 86% (n = 461/538) of GPs' self-assessed HF population with a 33% reduction (n = 1537/4678) in screening caseload. CONCLUSIONS: Diagnostic coding of HF in primary care health records is inaccurate with a high degree of under-registration and over-registration. An optimized query set enabled identification of more than 80% of GPs' self-assessed HF population.

Population-wide persistent hemostatic changes after vaccination with ChAdOx1-S.

Various vaccines were developed to reduce the spread of the Severe Acute Respiratory Syndrome Cov-2 (SARS-CoV-2) virus. Quickly after the start of vaccination, reports emerged that anti-SARS-CoV-2 vaccines, including ChAdOx1-S, could be associated with an increased risk of thrombosis. We investigated the hemostatic changes after ChAdOx1-S vaccination in 631 health care workers. Blood samples were collected 32 days on average after the second ChAdOx1-S vaccination, to evaluate hemostatic markers such as D-dimer, fibrinogen, α2-macroglobulin, FVIII and thrombin generation. Endothelial function was assessed by measuring Von Willebrand Factor (VWF) and active VWF. IL-6 and IL-10 were measured to study the activation of the immune system. Additionally, SARS-CoV-2 anti-nucleoside and anti-spike protein antibody titers were determined. Prothrombin and fibrinogen levels were significantly reduced after vaccination (-7.5% and -16.9%, p < 0.0001). Significantly more vaccinated subjects were outside the normal range compared to controls for prothrombin (42.1% vs. 26.4%, p = 0.026) and antithrombin (23.9% vs. 3.6%, p = 0.0010). Thrombin generation indicated a more procoagulant profile, characterized by a significantly shortened lag time (-11.3%, p < 0.0001) and time-to-peak (-13.0% and p < 0.0001) and an increased peak height (32.6%, p = 0.0015) in vaccinated subjects compared to unvaccinated controls. Increased VWF (+39.5%, p < 0.0001) and active VWF levels (+24.1 %, p < 0.0001) pointed toward endothelial activation, and IL-10 levels were significantly increased (9.29 pg/mL vs. 2.43 pg/mL, p = 0.032). The persistent increase of IL-10 indicates that the immune system remains active after ChAdOx1-S vaccination. This could trigger a pathophysiological mechanism causing an increased thrombin generation profile and vascular endothelial activation, which could subsequently result in and increased risk of thrombotic events.

Organisation and quality monitoring for point-of-care testing (POCT) in Belgium: proposal for an expansion of the legal framework for POCT into primary health care.

BACKGROUND: There is a trend towards decentralisation of laboratory tests by means of Point-of-Care testing (POCT). Within hospitals, Belgian law requires a POCT policy, coordinated by the clinical laboratory. There is however no legal framework for POCT performed outside the hospital: no reimbursement, no compulsory quality monitoring and no limits nor control on the prices charged to the patient. Uncontrolled use of POCT can have negative consequences for individual and public health. PROPOSAL: We propose that POCT outside hospitals would only be reimbursed for tests carried out within a legal framework, requiring evidence-based testing and collaboration with a clinical laboratory, because clinical laboratories have procedures for test validation and quality monitoring, are equipped for electronic data transfer, are familiar with logistical processes, can provide support when technical issues arise and can organise and certify training. Under these conditions the government investment will be offset by health benefits, e.g. fall in antibiotic consumption with POCT for CRP in primary care, quick response to SARS-CoV2-positive cases in COVID-19 triage centres. PRIORITIES: 1° extension of the Belgian decree on certification of clinical laboratories to decentralised tests in primary care; 2° introduction of a separate reimbursement category for POCT; 3° introduction of reimbursement for a limited number of specified POCT; 4° setup of a Multidisciplinary POCT Advisory Council, the purpose of which is to draw up a model for reimbursement of POCT, to select tests eligible for reimbursement and to make proposals to the National Institute for Health and Disability Insurance (RIZIV/INAMI).

Collection and storage requirements for urinary kidney injury molecule-1 (KIM-1) measurements in humans.

BACKGROUND: Urinary kidney injury molecule-1 (KIM-1) is a recently discovered biomarker for early renal damage. However, little is known about the collection and storage requirements prior to its measurement in human urine. METHODS: Samples of healthy volunteers were collected and aliquoted. The effect of pre-freezing time, thawing, addition of protease inhibitors, centrifugation, storage time (up to 1.5 years) and temperature (4°C, -20°C and -80°C) was tested. RESULTS: Addition of protease inhibitors and centrifugation prior to freezing did not affect the KIM-1 measurements. When samples were kept at room temperature for longer than 3 h before freezing or defrosted more than 1 h before measurement, mean KIM-1 values differed significantly compared to aliquots with minimal pre-freezing and thawing time. Samples frozen at -80°C were stable for up to 1.5 years; however an increasing number of freeze-thaw cycles adversely affected KIM-1 measurements. When stored at 4°C and -20°C, samples were less stable compared to those stored at -80°C. CONCLUSIONS: This study recommends that urine samples collected for KIM-1 measurements are frozen within 3 h after voiding and only be defrosted immediately prior to measurement. Addition of protease inhibitor and centrifugation prior to measurement is not necessary. Samples are preferably stored at -80°C and freeze-thaw cycles should be avoided.