Diurnal and day-to-day biological variation of salivary cortisol and cortisone.

OBJECTIVES: There is a growing interest in the relevance of salivary cortisol and cortisone concentrations in stress-related research. To correctly attribute the magnitude of salivary cortisol and cortisone variation as an effect of a stressful event, a coherent understanding of the day-to-day intra-individual and inter-individual variability across the diurnal cycle of the two steroids is required. However, such information is currently lacking. METHODS: This study aimed to overcome these existing limitations by performing an investigation of the biological variation (BV) of salivary cortisol and cortisone within one day and between five days using an LC-MS/MS method. Saliva samples were collected from 20 healthy volunteers immediately after waking up, at 8:00, 12:00, 15:00, 19:00 and 23:00 on each day over five days. All samples were analyzed in duplicate in one run. Nested ANOVA was used to calculate the sums of squares for analytical and biological components of variation. RESULTS: The within-subject BV of salivary cortisol and cortisone (CVI) ranged from a minimum of 29.3 and 19.0 % to a maximum of 56.5 and 49.1 %, respectively, while the between-subject biological variation (CVG) ranged from 29.7 and 29.0 % to 51.6 and 43.6 %. The reference change values (RCVs) ranged from 96 to 245 % for cortisol and from 55 to 194 % for cortisone. A medium index of individuality was observed for both compounds at all time points. CONCLUSIONS: This study provides updated BV estimates and RCVs for different times of day that can be used to assess the magnitude of change in biomarkers in future stress-related research.

EFLM Task Force Preparation of Labs for Emergencies (TF-PLE) recommendations for reinforcing cyber-security and managing cyber-attacks in medical laboratories.

The healthcare systems are a prime target for cyber-attacks due to the sensitive nature of the information combined with the essential need for continuity of care. Medical laboratories are particularly vulnerable to cyber-attacks for a number of reasons, including the high level of information technology (IT), computerization and digitization. Based on reliable and widespread evidence that medical laboratories may be inadequately prepared for cyber-terrorism, a panel of experts of the Task Force Preparation of Labs for Emergencies (TF-PLE) of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) has recognized the need to provide some general guidance that could help medical laboratories to be less vulnerable and better prepared for the dramatic circumstance of a disruptive cyber-attack, issuing a number of consensus recommendations, which are summarized and described in this opinion paper.

Associations between higher plasma ferritin and hepcidin levels with liver stiffness in patients with type 2 diabetes: An exploratory study.

BACKGROUND: Currently, there is no information about the association between circulating levels of ferritin and hepcidin and liver fibrosis in patients with type 2 diabetes mellitus (T2DM) and non-alcoholic fatty liver disease (NAFLD). METHODS: We enrolled 153 patients with T2DM with no known liver diseases, who consecutively attended our diabetes outpatient service and who underwent liver ultrasonography and liver stiffness measurement (LSM) by vibration-controlled transient elastography (Fibroscan® for the non-invasive assessment of liver fibrosis). Plasma ferritin and hepcidin concentrations were measured with an electrochemiluminescence immunoassay and mass spectrometry-based assay, respectively. RESULTS: After stratification of patients by LSM tertiles [1st tertile median LSM: 3.6 (interquartile range: 3.3-4.0) kPa, 2nd tertile: 5.3 (4.9-5.9) kPa and 3rd tertile: 7.9 (6.7-9.4) kPa], we found that plasma ferritin and hepcidin concentrations increased across LSM tertiles [median ferritin: 68.7 (interquartile range: 25.1-147) vs. 85.8 (48.3-139) vs. 111 (59.3-203) µg/L, p = 0.021; median hepcidin: 2.5 (1.1-5.2) vs. 4.4 (2.5-7.3) vs. 4.1 (1.9-6.8) nmol/L, p = 0.032]. After adjustment for age, sex, diabetes duration, waist circumference, haemoglobin A1c, HOMA-insulin resistance score, triglycerides, haemoglobin, presence of hepatic steatosis on ultrasonography and patatin-like phospholipase domain-containing-3 (PNPLA3) rs738409 genetic variant, higher plasma ferritin levels were associated with greater LSM values (adjusted-odds ratio 2.10, 95% confidence interval 1.23-3.57, p = 0.005). Higher plasma hepcidin levels were also associated with greater LSM values (adjusted-odds ratio 1.90, 95% confidence interval 1.15-3.13, p = 0.013). CONCLUSIONS: Higher levels of plasma ferritin and hepcidin were associated with greater NAFLD-related liver fibrosis (assessed by LSM) in patients with T2DM, even after adjustment for established cardiometabolic risk factors, diabetes-related variables and other potential confounders.

Immunogenicity and Safety of the BNT162b2 COVID-19 Vaccine in Patients with Cystic Fibrosis with or without Lung Transplantation.

Cystic fibrosis (CF) is characterized by a progressive decline in lung function, which may be further impaired by viral infections. CF is therefore considered a comorbidity of coronavirus disease 2019 (COVID-19), and SARS-CoV-2 vaccine prioritization has been proposed for patients with (pw)CF. Poor outcomes have been reported in lung transplant recipients (LTR) after SARS-CoV-2 infections. LTR have also displayed poor immunization against SARS-CoV-2 after mRNA-based BNT162b2 vaccination, especially in those undergoing immunosuppressive treatment, mostly those receiving mycophenolate mofetil (MMF) therapy. We aimed to determine here the immunogenicity and safety of the BNT162b2 vaccine in our cohort of 260 pwCF, including 18 LTR. Serum levels of neutralizing anti-SARS-CoV-2 IgG and IgA antibodies were quantified after the administration of two doses. PwCF displayed a vaccine-induced IgG and IgA antiviral response comparable with that seen in the general population. We also observed that the immunogenicity of the BNT162b2 vaccine was significantly impaired in the LTR subcohort, especially in patients undergoing MMF therapy. The BNT162b2 vaccine also caused minor adverse events as in the general population, mostly after administration of the second dose. Overall, our results justify the use of the BNT162b2 vaccine in pwCF and highlight the importance of a longitudinal assessment of the anti-SARS-CoV-2 IgG and IgA neutralizing antibody response to COVID-19 vaccination.

Plasma Bile Acid Profiling and Modulation of Secreted Mucin 5AC in Cholangiocarcinoma.

Studies investigating the potential role of circulating bile acids (BAs) as diagnostic biomarkers for cholangiocarcinoma (CCA) are sparse and existing data do not adjust for confounding variables. Furthermore, the mechanism by which BAs affect the expression of the oncogenic mucin 5AC (MUC5AC) has never been investigated. We performed a case-control study to characterise the profile of circulating BAs in patients with CCA (n = 68) and benign biliary disease (BBD, n = 48) with a validated liquid chromatography-tandem mass spectrometry technique. Odd ratios (OR) for CCA associations were calculated with multivariable logistic regression models based on a directed acyclic graph structure learning algorithm. The most promising BAs were then tested in an in vitro study to investigate their interplay in modulating MUC5AC expression. The total concentration of BAs was markedly higher in patients with CCA compared with BBD controls and accompanied by a shift in BAs profile toward a higher proportion of primary conjugated BAs (OR = 1.50, CI: 1.14 to 1.96, p = 0.003), especially taurochenodeoxycholic acid (TCDCA, OR = 42.29, CI: 3.54 to 504.63, p = 0.003) after multiple adjustments. Western blot analysis of secreted MUC5AC in human primary cholangiocytes treated with primary conjugated BAs or with TCDCA alone allowed us to identify a novel 230 kDa isoform, possibly representing a post-translationally modified MUC5AC specie.

Development of a new ultra-high-performance liquid chromatography-tandem mass spectrometry method for the determination of digoxin and digitoxin in plasma: Comparison with a clinical immunoassay.

Cardiac glycosides digoxin and digitoxin are used in therapy for the treatment of congestive heart failure. Moreover, these compounds can be responsible for intoxication cases caused by fortuitous ingestion of leaves of Digitalis. Due to the narrow therapeutic range of these drugs, therapeutic drug monitoring is recommended in the clinical practice. In this context, immunoassays-based methods are generally employed but digoxin- and digitoxin-like compounds can interfere with the analysis. The aim of this study was to develop and validate an original UPLC-MS/MS method for the determination of digoxin and digitoxin in plasma. The method shows adequate sensitivity and selectivity with acceptable matrix effects and very good linearity, accuracy, precision, and recovery. A simple liquid-liquid extraction procedure was used for sample clean-up. The method was applied for the analysis of n = 220 plasma samples collected in two different clinical chemistry laboratories and previously tested by the same immunoassay. The statistical comparison showed a relevant negative bias of the UPLC-MS/MS method versus the immunoassay. These results are consistent with an immunoassay overestimation of digoxin plasmatic levels due to cross-reaction events with endogenous digoxin-like substances.

Artificial intelligence at the time of COVID-19: who does the lion's share?

OBJECTIVES: The development and use of artificial intelligence (AI) methodologies, especially machine learning (ML) and deep learning (DL), have been considerably fostered during the ongoing coronavirus disease 2019 (COVID-19) pandemic. Several models and algorithms have been developed and applied for both identifying COVID-19 cases and for assessing and predicting the risk of developing unfavourable outcomes. Our aim was to summarize how AI is being currently applied to COVID-19. METHODS: We conducted a PubMed search using as query MeSH major terms "Artificial Intelligence" AND "COVID-19", searching for articles published until December 31, 2021, which explored the possible role of AI in COVID-19. The dataset origin (internal dataset or public datasets available online) and data used for training and testing the proposed ML/DL model(s) were retrieved. RESULTS: Our analysis finally identified 292 articles in PubMed. These studies displayed large heterogeneity in terms of imaging test, laboratory parameters and clinical-demographic data included. Most models were based on imaging data, in particular CT scans or chest X-rays images. C-Reactive protein, leukocyte count, creatinine, lactate dehydrogenase, lymphocytes and platelets counts were found to be the laboratory biomarkers most frequently included in COVID-19 related AI models. CONCLUSIONS: The lion's share of AI applied to COVID-19 seems to be played by diagnostic imaging. However, AI in laboratory medicine is also gaining momentum, especially with digital tools characterized by low cost and widespread applicability.

The Role of Epigenetics in the Regulation of Hemostatic Balance.

Epigenetics, a term conventionally used to explain the intricate interplay between genes and the environment, is now regarded as the fundament of developmental biology. Several lines of evidence garnered over the past decades suggest that epigenetic alterations, mostly encompassing DNA methylation, histone tail modifications, and generation of microRNAs, play an important, though still incompletely explored, role in both primary and secondary hemostasis. Epigenetic variations may interplay with platelet functions and their responsiveness to antiplatelet drugs, and they may also exert a substantial contribution in modulating the production and release into the bloodstream of proteins involved in blood coagulation and fibrinolysis. This emerging evidence may have substantial biological and clinical implications. An enhanced understanding of posttranscriptional mechanisms would help to clarify some remaining enigmatic issues in primary and secondary hemostasis, which cannot be thoughtfully explained by genetics or biochemistry alone. Increased understanding would also pave the way to developing innovative tests for better assessment of individual risk of bleeding or thrombosis. The accurate recognition of key epigenetic mechanisms in hemostasis would then contribute to identify new putative therapeutic targets, and develop innovative agents that could be helpful for preventing or managing a vast array of hemostasis disturbances.

Comprehensive assessment of humoral response after Pfizer BNT162b2 mRNA Covid-19 vaccination: a three-case series.

OBJECTIVES: Since universal vaccination is a pillar against coronavirus disease 2019 (COVID-19), monitoring anti-SARS-CoV-2 neutralizing antibodies is essential for deciphering post-vaccination immune response. METHODS: Three healthcare workers received 30 µg BNT162b2 mRNA Covid-19 Pfizer Vaccine, followed by a second identical dose, 21 days afterwards. Venous blood was drawn at baseline and at serial intervals, up to 63 days afterwards, for assessing total immunoglobulins (Ig) anti-RBD (receptor binding domain), anti-S1/S2 and anti-RBD IgG, anti-RBD and anti-N/S1 IgM, and anti-S1 IgA. RESULTS: All subjects were SARS-CoV-2 seronegative at baseline. Total Ig anti-RBD, anti-S1/S2 and anti-RBD IgG levels increased between 91 and 368 folds until 21 days after the first vaccine dose, then reached a plateau. The levels raised further after the second dose (by ∼30-, ∼8- and ∼8-fold, respectively), peaking at day 35, but then slightly declining and stabilizing ∼50 days after the first vaccine dose. Anti-S1 IgA levels increased between 7 and 11 days after the first dose, slightly declined before the second dose, after which levels augmented by ∼24-fold from baseline. The anti-RBD and anti-N/S1 IgM kinetics were similar to that of anti-S1 IgA, though displaying substantially weaker increases and modest peaks, only 4- to 7-fold higher than baseline. Highly significant inter-correlation was noted between total Ig anti-RBD, anti-S1/S2 and anti-RBD IgG (all r=0.99), whilst other anti-SARS-CoV-2 antibodies displayed lower, though still significant, correlations. Serum spike protein concentration was undetectable at all-time points. CONCLUSIONS: BNT162b2 mRNA vaccination generates a robust humoral immune response, especially involving anti-SARS-Cov-2 IgG and IgA, magnified by the second vaccine dose.

Drug-Induced Thrombocytopenia: Mechanisms and Laboratory Diagnostics.

Thrombocytopenia is a condition characterized by a decreased number of platelets in peripheral blood, which can be caused by a myriad of both congenital and acquired disorders. Drug-induced thrombocytopenia (DIT) deserves a special focus since its cumulative incidence can be as high as 10 cases per million population per year, with a prevalence of approximately 25% in critically ill patients. This condition is usually suspected following identification of an acute and severe decrease in platelet count, with values usually < 50 ×109/L, thus potentially exposing patients to an increased risk of developing spontaneous hemorrhages. Conversely, however, some drug-related thrombocytopenias are instead (and perhaps counterintuitively) associated with increased thrombosis risk. Although a vast number of drugs have been implicated in DIT, the underlying pathogenetic mechanisms are essentially bifold, encompassing reduced platelet production due to bone marrow suppression (thus insufficient maturation or inefficient expansion of megakaryocytes, impaired release of platelets, or accelerated platelet apoptosis) or accelerated clearance of platelets from the circulation. This second form of DIT can be sustained by nonimmune, immune-mediated, or autoimmune mechanisms. An early and accurate diagnosis of DIT, which is crucial for reversing an otherwise unfavorable clinical outcome, is essentially based on the complete blood cell count, blood smear analysis, and performance of specific functional or immunochemical tests aimed at demonstrating the presence of antiplatelet antibodies.

Mass spectrometry and total laboratory automation: opportunities and drawbacks.

The diffusion of laboratory automation, initiated nearly 50 years ago with consolidation of preanalytical, clinical chemistry and immunochemistry workstations, is now also gradually embracing mass spectrometry (MS). As for other diagnostic disciplines, the automation of MS carries many advantages, such as efficient personnel management (i.e. improving working atmosphere by decreasing manual activities, lowering health risks, simplifying staff training), better organization (i.e. reducing workloads, improving inventory handling, increasing analytical process standardization) and the possibility to reduce the number of platforms. The development and integration of different technologies into automated MS analyzers will also generate technical and practical advantages, such as prepackaged and ready-to-use reagents, automated dispensing, incubation and measurement, automated sample processing (e.g. system fit for many models of laboratory automation, bar code readers), multiplex testing, automatic data processing, also including quality control assessment, and automated validation/interpretation (e.g. autoverification). A new generation of preanalytical workstations, which can be directly connected to MS systems, will allow the automation of manual extraction and elimination of time-consuming activities, such as tube labeling and capping/decapping. The use of automated liquid-handling platform for pipetting samples, along with addition of internal standards, may then enable the optimization of some steps of extraction and protein precipitation, thus decreasing turnaround time and increasing throughput in MS testing. Therefore, this focused review is aimed at providing a brief update on the importance of consolidation and integration of MS platforms in laboratory automation.

Short-term stability of free metanephrines in plasma and whole blood.

Background Analysis of plasma metanephrine (MN) and normetanephrine (NMN) with liquid chromatography tandem mass spectrometry (LC-MS/MS) is the gold standard for the screening of pheochromocytomas and paragangliomas (PPGLs). As scarce information is available on the stability of MNs in diagnostic samples, this study was aimed at analyzing the short-term stability of plasma free MNs in whole blood and plasma, using LC-MS/MS. Methods The stability of plasma MNs was evaluated after sample collection at 1, 2 and 3 h in whole blood, and at 2, 4 and 6 h in centrifuged samples. Both studies were performed while maintaining the samples at room temperature (RT) and at 4 °C. The ClinMass Complete Kit (Recipe, Munchen, Germany) was used for measuring MNs with LC-MS/MS (Nexera X2 UHPLC-4500MD Sciex). Differences from the baseline (T0) were assessed using repeated measures one-way ANOVA, Students' paired t-test and a comparison of the mean percentage changes with the total change limit (TCL). Results Statistically significant differences from T0 were found for both MNs (p < 0.001) in whole blood stored at RT, and for NMN (p = 0.028) but not MN (p = 0.220) at 4 °C. The mean difference exceeded the TCL after 1 h and 3 h at RT for MN, and after 1 h at RT for NMN. Statistically significant differences from T0 were only observed in the plasma samples for NMN at RT (p = 0.012), but the variation was within the TCL. Conclusions MN and NMN displayed different patterns of stability before and after centrifugation. Even short-time storage at RT in whole blood should hence be avoided.

Effects of endurance exercise on serum concentration of calcitonin gene-related peptide (CGRP): a potential link between exercise intensity and headache.

Background Calcitonin gene-related peptide (CGRP) is a powerful neuropeptide that is strongly involved in headache pain pathogenesis by triggering vasodilation, mast cell degranulation and neurogenic inflammation. This evidence has prompted us to investigate the acute influence of endurance exercise on CGRP concentration in blood. Methods The study population consisted of 48 male amateur runners, who ran a half-marathon distance at 75%-85% of maximal oxygen uptake. Blood was drawn before the run (pre-run) and immediately after each runner ended his trial (post-run). The serum concentration of CGRP was measured with a commercial enzyme-linked immunosorbent assay (ELISA) technique. Results Overall, 22/48 subjects (45.8%) reported suffering from headache, three of whom (6.2%) had an exertional headache, whilst 26/48 (54.2%) subjects did not report at least one headache episode during the previous 6 months (i.e. headache-free). All 48 athletes successfully covered the 21.1 km distance. Serum concentration of CGRP significantly increased by 1.5-fold in the entire group, as well as in the headache-positive and headache-free cohorts. Univariate Spearman's correlation revealed that post-run variation of serum CGRP was significantly and inversely associated with running time (r = -0.30; p = 0.036). Conclusions The serum concentration of CGRP is significantly enhanced by medium-distance endurance exercise and the post-exercise increase is dependent on running intensity. Accordingly, high-exercise intensity might be directly related to triggering both exertional headache and/or migraine episodes.

Harms and Benefits of Using Aspirin for Primary Prevention of Cardiovascular Disease: A Narrative Overview.

Aspirin is one of the most often used drugs for prevention and treatment of a variety of thrombotic disorders. This narrative review aims to provide an overview of evidence highlighting potential benefits and relative harms of aspirin in primary prevention of cardiovascular disease. The authors summarize key findings of the ASPirin in Reducing Events in the Elderly (ASPREE) Investigator Group randomized trial and also provide a comparative overview of recent meta-analyses. Overall, all-cause mortality was largely heterogeneous, with some meta-analyses showing a modestly decreased risk in patients taking aspirin, with others reporting no effects, but the ASPREE Investigator Group trial evidencing 14% higher risk. Regarding cardiovascular disease, the most favorable impact could be noted for major adverse cardiovascular events, with most meta-analyses reporting a decreased risk in people receiving aspirin. Conversely, the ASPREE Investigator Group trial demonstrated no significant impact of aspirin on risk of cardiovascular mortality or ischemic stroke. A modest favorable effect of aspirin in decreasing the risk of myocardial infarction was noted in two meta-analyses, but not in other reports or in the ASPREE Investigator Group trial. Furthermore, one meta-analysis reported a lower risk of future cancer, others failed to report a significant effect, and the ASPREE Investigator Group trial reported a 31% increased risk. Unlike these conflicting outcomes, the bleeding risk of patients receiving aspirin was found to be consistently enhanced in all reports reviewed. These recent findings would lead us to conclude that the harms of aspirin in primary prevention of cardiovascular disease may be larger than the benefits, especially in the elderly general population.

Individual fatty acids in erythrocyte membranes are associated with several features of the metabolic syndrome in obese children.

PURPOSE: Obesity leads to the clustering of cardiovascular (CV) risk factors and the metabolic syndrome (MetS) also in children and is often accompanied by non-alcoholic fatty liver disease. Quality of dietary fat, beyond the quantity, can influence CV risk profile and, in particular, omega-3 fatty acids (FA) have been proposed as beneficial in this setting. The aim of the study was to evaluate the associations of individual CV risk factors, characterizing the MetS, with erythrocyte membrane FA, markers of average intake, in a group of 70 overweight/obese children. METHODS: We conducted an observational study. Erythrocyte membrane FA were measured by gas chromatography. Spearman correlation coefficients (rS) were calculated to evaluate associations between FA and features of the MetS. RESULTS: Mean content of Omega-3 FA was low (Omega-3 Index = 4.7 ± 0.8%). Not omega-3 FA but some omega-6 FA, especially arachidonic acid (AA), were inversely associated with several features of the MetS: AA resulted inversely correlated with waist circumference (rS = - 0.352), triglycerides (rS = - 0.379), fasting insulin (rS = - 0.337) and 24-h SBP (rS = - 0.313). Total amount of saturated FA (SFA) and specifically palmitic acid, correlated positively with waist circumference (rS = 0.354), triglycerides (rS = 0.400) and fasting insulin (rS = 0.287). Fatty Liver Index (FLI), a predictive score of steatosis based on GGT, triglycerides and anthropometric indexes, was positively correlated to palmitic acid (rS = 0.515) and inversely to AA (rS = - 0.472). CONCLUSIONS: Our data suggest that omega-6 FA, and especially AA, could be protective toward CV risk factors featuring the MetS and also to indexes of hepatic steatosis in obese children, whereas SFA seems to exert opposite effects.

Proteomics and frailty: a clinical overview.

INTRODUCTION: Frailty is consequent to age-dependent deregulation of several biological pathways and systems, encompassing namely sarcopenia, age-associated hormonal derangements, inflammation, and nutritional or metabolic deficiencies. Although the prevalence of frailty is usually between 10% and 20% in the general elderly population, its overall burden will increase exponentially along with the predictable prolongation of life expectancy. Risk prediction and early diagnosis will hence become pivotal for mitigating the clinical, social, and economic impact of this condition. The currently available research suggests that no single laboratory biomarker can efficiently help predicting or diagnosing frailty. However, its multifaceted pathogenesis suggests that a multi-marker approach, preceded by preliminary identification of specific proteomic signatures, may be the most promising strategy in frailty diagnostics. Areas covered: This review critically analyzes recent proteomic studies exploring protein profiles in non-frail and frail subjects. Expert commentary: Results of some recent proteomic studies attest that muscle proteome, chronic low-grade inflammation (inflammaging), along with characteristic vascular and hemostasis proteomic profiles, may help predict or diagnose frailty. Larger prospective studies are needed for confirming these findings and enabling their replication in real life scenarios. Albeit proteomic research in the field of age-dependent biologic impairment is in embryo, proteomics holds the greatest potential in frailty diagnostics.

Prothrombotic State Induced by Middle-Distance Endurance Exercise in Middle-Aged Athletes.

Since the impact of possible prothrombotic factors on blood coagulation resulting from exercise remains elusive, this study investigated the acute effects of middle-distance endurance running on blood coagulation parameters in middle-aged athletes. The study population consisted of 33 male endurance runners who were engaged in a 21.1 km run under competitive conditions. Blood samples were collected before the run, immediately after the run, and 3 hours after run completion. Samples were assessed for activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen, D-dimer, factor VIII (FVIII), von Willebrand factor antigen (VWF:Ag), endogenous thrombin potential (area under the curve of thrombin generation [TGA-AUC]), and peak thrombin generation (TGA-PK). Post-run variations were expressed as delta (Δ). At baseline, APTT was found to be significantly associated with ABO blood group, VWF:Ag, and FVIII; fibrinogen with age; VWF:Ag with BMI, training regimen, and ABO blood group; APTT with FVIII; FVIII with VWF:Ag and ABO blood group; APTT with VWF:Ag; and TGA-PK with ABO blood group, PT, and TGA-AUC. Immediately after the run, statistically significant increases were observed for PT, D-dimer, VWF:Ag, and FVIII, while statistically significant reductions could be observed for APTT, TGA-AUC, and TGA-PK. Fibrinogen values remained unchanged. Significant correlations were observed between Δ VWF:Ag and Δ FVIII, Δ APTT and Δ VWF:Ag, Δ APTT and Δ FVIII, Δ TGA-AUC and Δ TGA-PK, and between Δ D-dimer and Δ TGA-AUC and Δ TGA-PK. No Δ variation was associated with running time. The results of this study seemingly suggest that middle-distance competitive running may evoke several prothrombotic changes in blood coagulation.

Impact of blood cell counts and volumes on glucose concentration in uncentrifuged serum and lithium-heparin blood tubes.

BACKGROUND: Although it is known that glucose concentration exhibits a time-dependent decay in uncentrifuged serum and lithium-heparin blood tubes, no evidence exists on how this variation may depend on blood cell counts (CBC) and volumes. METHODS: Venous blood was drawn from 30 non fasting healthy volunteers into three serum and three lithium-heparin tubes. One serum and lithium-heparin tubes were centrifuged within 15 min after collection and glucose was measured with a hexokinase assay. The second and third serum and lithium-heparin tubes were maintained at room temperature for 1 and 2 h after the first tubes were centrifuged. These other tubes were then centrifuged and glucose was measured. CBC was performed in the first lithium-heparin tube, before centrifugation. RESULTS: The mean decrease of glucose was higher in lithium-heparin plasma than in serum (0.33 vs. 0.24 mmol/L/h; p<0.001). Glucose concentration decreased by 7% and 5% per hour in lithium-heparin plasma and serum, respectively. In univariate analysis, the absolute decrease of glucose concentration was associated with sex (higher in men than in women), red blood cell (RBC) count, hematocrit, white blood cell (WBC) count, neutrophils and monocytes in both lithium-heparin plasma and serum. In multivariate analysis, the decrease of glucose concentration remained independently associated with RBC, WBC, neutrophils and monocytes in both sample matrices. No significant association was found with platelet number and erythrocyte or platelet volume. CONCLUSIONS: Glucose concentration decrease in uncentrifuged lithium-heparin and serum tubes depends on the baseline number of RBC, WBC, neutrophils and monocytes within the tubes.