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The article discusses the clinical assessment of the Ortho VITROS SARS-CoV-2 antigen chemiluminescence immunoassay for the diagnosis of COVID-19. The study evaluated the performance of the immunoassay in detecting the SARS-CoV-2 virus in patients with suspected COVID-19. The results showed that the immunoassay had good diagnostic accuracy and sensitivity, especially in patients with high viral load. The study suggests that the immunoassay could be a fast, efficient, and relatively inexpensive method for identifying individuals with COVID-19. [Extracted from the article]

This study investigated the feasibility and clinical value of using a novel, automated and high-throughput SARS-CoV-2 Interferon Gamma Release Assay (IGRA), combined with total anti-SARS-CoV-2 antibodies assessment, for evaluating the immune response after bivalent BNT162b2 vaccination. A cohort of healthcare workers, who already underwent primary vaccination and boosting with monovalent BNT162b2 vaccine, received a booster dose of the new BNT162b2 bivalent formulation. Blood samples were taken immediately before vaccination (T0) and 1 month afterwards (T1). Humoral and cellular immunity were assayed with Roche Elecsys Anti-SARS-CoV-2 and Roche Elecsys IGRA SARS-CoV-2, respectively. The study population consisted of 51 subjects (median age: 43 years; 51% females). Total anti-SARS-CoV-2 antibodies and IGRA SARS-CoV-2 values increased at T1 from 9,050 to 25,000 BAU/mL (p<0.001), and from 0.44 to 0.78 IU/mL (p=0.385), accounting for median increase of 2.0 and 1.6 folds, respectively. Increased T1 values of total anti-SARS-CoV-2 antibodies and IGRA SARS-CoV-2 were recorded in 100% and 68.6% subjects, respectively. In those with baseline values below the median, post-vaccine levels displayed larger increases of 3.3 and 5.1 folds for anti-SARS-CoV-2 total antibodies and IGRA SARS-CoV-2, respectively. The variation of total anti-SARS-CoV-2 antibodies was inversely associated with their T0 values (r=−0.97; p<0.001), whilst that of IGRA SARS-CoV-2 was inversely associated with its T0 value (r=−0.58; p<0.001). No other signifcant associations were found with demographical or clinical variables, including side effects. The bivalent BNT162b2 vaccine booster enhances humoral and cellular immunity against SARS-CoV-2, especially in recipients with lower baseline biological protection. [ABSTRACT FROM AUTHOR]

Keywords: antibodies; COVID-19; immunity; interferon gamma release assay; SARS-CoV-2; vaccination EN antibodies COVID-19 immunity interferon gamma release assay SARS-CoV-2 vaccination e172 e174 3 07/18/23 20230801 NES 230801 To the Editor, There is now incontrovertible evidence that the accurate characterization of immunity against various pathogens such as the severe acute respiratory syndrome coronavirus disease 2 (SARS-CoV-2) should encompass the assessment of both humoral and cellular immunity, whereby T cell response plays a vital, irreplaceable role in preventing the risk of developing severe forms of coronavirus disease 2019 (COVID-19) [[1]]. Prior vaccination enhances immune responses during SARS-CoV-2 breakthrough infection with early activation of memory T cells followed by production of potent neutralizing antibodies. Antibodies, COVID-19, immunity, interferon gamma release assay, SARS-CoV-2, vaccination. [Extracted from the article]

This proof of concept study was aimed to validate the hypothesis that the time of positivization of SARS-CoV-2 self-performed rapid diagnostic tests (RDTs) may reflect the actual viral load in the specimen. A SARS-CoV-2 positive sample with high viral load was diluted and concomitantly assayed with molecular assay (Xpert Xpress SARS-CoV-2) and RDT (COVID-VIRO ALL IN RDT). The (mean cycle threshold; Ct) values and RDT positivization times of these dilutions were plotted and interpolated by calculating the best fit. The parameters of this equation were then used for converting the positivization times into RDT-estimated SARS-CoV-2 Ct values in routine patient samples. The best fit between measured and RDT-estimated Ct values could be achieved with a 2-degree polynomial curve. The RDT-estimated Ct values exhibited high correlation (r=0.996) and excellent Deming fit (y=1.01 × x − 0.18) with measured Ct values. In 30 consecutive patients with positive RDT test, the correlation between RDT positivization time and measured Ct value was r=0.522 (p=0.003). The correlation of RDT-estimated and measured Ct values slightly improved to 0.577 (Deming fit: y=0.44 × x + 11.08), displaying a negligible bias (1.0; 95% CI, −0.2 to 2.2; p=0.105). Concordance of RDT-estimated and measured Ct values at the <20 cut-off was 80%, with 0.84 sensitivity and 0.73 specificity. This proof of concept study demonstrates the potential feasibility of using RDTs for garnering information on viral load in patients with acute SARS-CoV-2 infection. [ABSTRACT FROM AUTHOR]

Background: Rapid SARS-CoV-2 antigen tests are potentially useful tools for screening carriers with high viral load. This study was aimed to assess the potential association between viral load and positivization time of a manual SARS-CoV-2 commercial antigen test in routine nasopha-ryngeal specimens. Methods: In a sample of subjects undergoing routine diagnostic testing, SARS-CoV-2 positivity of nasopharyngeal samples was assayed with both molecular (Altona Diagnostics RealStar SARS-CoV-2 RT-PCR Kit) and antigenic (Roche SARS-CoV-2 Rapid Antigen Test) tests. Positivization time of rapid antigen test was correlated and compared with viral load expressed as mean of SARS-CoV-2 E/S genes cycle threshold (Ct) values. Results: The study sample consisted of 106 patients (median age 48 years, 55 women) with positive results of rapid SARS-CoV-2 antigen testing. A highly significant Spearman's correlation was found between mean SARS-CoV-2 E/S genes Ct values and positivization time of manual antigen test (r= 0.70; p<0.001). The positivization time of rapid SARS-CoV-2 antigen test displayed an area under the curve of 0.82 (95%CI, 0.74-0.89) for predicting nasopharyngeal samples with high viral load (i.e., mean Ct <20). A positivization time cut-off of 32 sec had 94.9% sensitivity and 58.2% specificity for detecting specimens with high viral load. The overall agreement between mean Ct value <20 and positivization time <32 sec was 70.8%. Conclusions: Positivization time of rapid SARS-CoV-2 antigen tests may provide easy and rapid information on viral load, thus making this type of manual assay potentially suitable for quick and reliable detection and isolation of super-carriers. [ABSTRACT FROM AUTHOR]

Similarly, the rate of subjects with anti-SARS-CoV-2 spike trimeric IgG values >264 kBAU/L reached 100% after 1 month from completing the primary vaccination cycle, but then decreased to 77.4% and 47.2% after 6 months and immediately before receiving the vaccine booster dose, respectively (Figure 2). Keywords: antibodies; COVID-19; immune response; SARS-CoV-2; vaccination EN antibodies COVID-19 immune response SARS-CoV-2 vaccination 930 933 4 05/12/22 20220501 NES 220501 Introduction Several lines of evidence now attest that laboratory medicine plays an essential role not only in diagnosing acute SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infections, but also for predicting and monitoring the efficacy of coronavirus disease 2019 (COVID-19) vaccination [[1]]. Moreover, we also showed that the vaccine booster dose is effective to increase anti-SARS-CoV-2 spike trimeric IgG antibodies levels by nearly threefold compared to immediately after completing the primary vaccination cycle. [Extracted from the article]

Background: This study aimed at monitoring the kinetics of serum total anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) antibodies in a cohort of healthcare workers after voluntary vaccination with Pfizer-BioNTech coronavirus disease 2019 (COVID-19) mRNA-based vaccine. Methods: The study population consisted of 787 healthcare workers (mean age 44±12 years; 66% females), who received two 30 pg doses of Pfizer-BioNTech COVID-19 vaccine, 3 weeks apart. Venous blood was drawn before the first vaccine dose, immediately before the second vaccine dose, and then at 1, 3 and 6 months after the second vaccine dose. Serological testing employed the total anti-SARS-CoV-2 antibodies measurement with Roche Elecsys Anti-SARS-CoV-2 S chemiluminescent immunoassay. Results: The median serum levels of total anti-SARS-CoV-2 antibodies reached the peak (1762 kU/L) 1 month after the second vaccine dose, but tended to progressively decline at the 3-month (1086 kU/L) and 6-month (802 kU/L) follow-up points. Overall, the values after 3-and 6months were 37% and 57% lower than the corresponding concentrations measured at the peak. No healthcare worker had total anti-SARS-CoV-2 antibodies below the method-dependent cut-off after 6 months. The decline compared to the peak was more accentuated in baseline seropositive persons than in those who were baseline seronegative (74% vs. 52%) cohort. The 6-month post-vaccination anti-SARS-CoV-2 antibodies in subjects aged <65 years remained over 2-fold higher than in those aged >65 years (813 vs. 343 kU/L) and also remained consistently higher in women than in men. Conclusions: Gradual decline of total anti-SARS-CoV-2 antibodies occurred 6 months after Pfizer-BioNTech COVID-19 vaccination, though values remained higher than the method-dependent cut-off, with no case of sero-negativization. [ABSTRACT FROM AUTHOR]

Background: Most studies on immune response after coronavirus disease 2019 (COVID-19) vaccination focused on serum IgG antibodies and cell-mediated immunity, discounting the role of anti-SARS-CoV-2 neutralizing IgA antibodies in preventing viral infection. This study was aimed to quantify serum IgG and IgA neutralizing antibodies after mRNA COVID-19 vaccination in baseline SARS-CoV-2 seronegative healthcare workers. Methods: The study population consisted of 181 SARS-CoV-2 seronegative healthcare workers (median age 42 years, 59.7% women), receiving two doses of Pfizer COVID-19 vaccine BNT162b2 (Comirnaty). Serum samples were collected before receiving the first vaccine dose, 21 days (before the second vaccine dose) and 50 days afterwards. We then measured anti-spike tri meric IgG (Liaison XL, DiaSorin), anti-spike receptor binding domain (RBD) IgG (Access 2, Beckman Coulter) and anti-spike S1 subunit IgA (ELISA, Euroimmun). Results were presented as median and interquartile range (IQR). Results: Vaccine administration elicited all anti-SARS-CoV-2 antibodies measured. Thirty days after the second vaccine dose, 100% positivization occurred for anti-spike trimeric IgG and anti-spike RBD IgG, whilst 1.7% subjects remained anti-spike S1 IgA negative. The overall increase of antibodies level ratio over baseline after the second vaccine dose was 576.1 (IQR, 360.7-867.8) for anti-spike tri meric IgG, 1426.0 (IQR, 742.0-2698.6) for anti-spike RBD IgG, and 20.2 (IQR, 12.5-32.1) for anti-spike S1 IgA. Significant inverse association was found between age and overall increase of anti-spike trimeric IgG (r=-0.24; p=0.001) and anti-spike S1 IgA (r=-0.16; p=0.028), but not with anti-spike RBD IgG (r=-0.05; p=0.497). Conclusions: mRNA COVID-19 vaccination elicits sustained serum levels of anti-spike tri meric IgG and anti-spike RBD IgG, while also modestly but significantly increasing those of anti-spike S1 IgA. [ABSTRACT FROM AUTHOR]

Objectives: Novel point-of-care antigen assays present a promising opportunity for rapid screening of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. The purpose of this study was the clinical assessment of the new Roche SARS-CoV-2 Rapid Antigen Test. Methods: The clinical performance of Roche SARS-CoV-2 Rapid Antigen Test was evaluated vs. a reverse transcription polymerase chain reaction (RT-PCR) laboratory-based assay (Seegene AllplexTM2019-nCoV) in nasopharyngeal swabs collected from a series of consecutive patients referred for SARS-CoV-2 diagnostics to the Pederzoli Hospital (Peschiera del Garda, Verona, Italy) over a 2-week period. Results: The final study population consisted of 321 consecutive patients (mean age, 46 years and IQR, 32–56 years; 181 women, 56.4%), with 149/321 (46.4%) positive for SARS-CoV-2 RNA via the Seegene AllplexTM2019-nCoV Assay, and 109/321 (34.0%) positive with Roche SARS-CoV-2 Rapid Antigen Test, respectively. The overall accuracy of Roche SARS-CoV-2 Rapid Antigen Test compared to molecular testing was 86.9%, with 72.5% sensitivity and 99.4% specificity. Progressive decline in performance was observed as cycle threshold (Ct) values of different SARS-CoV-2 gene targets increased. The sensitivity was found to range between 97–100% in clinical samples with Ct values <25, between 50–81% in those with Ct values between 25 and <30, but low as 12–18% in samples with Ct values between 30 and <37. Conclusions: The clinical performance of Roche SARS-CoV-2 Rapid Antigen Test is excellent in nasopharyngeal swabs with Ct values <25, which makes it a reliable screening test in patients with high viral load. However, mass community screening would require the use of more sensitive techniques. [ABSTRACT FROM AUTHOR]

In multiple linear regression analysis both 1-month post-booster antibodies values (p<0.001) and age (p=0.004) remained negatively associated with the percentage decrease of total anti-SARS-CoV-2 antibodies measured 1 and 3 months after the booster. Keywords: antibodies; COVID-19; immune response; SARS-CoV-2; vaccination EN antibodies COVID-19 immune response SARS-CoV-2 vaccination e181 e183 3 06/21/22 20220701 NES 220701 To the Editor, Although widespread vaccination for preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) complications is now universally considered a highly effective and safe anti-pandemic strategy, vaccine efficacy has been clearly shown to wane over time, thus paving the way to administration of an additional (so-called "booster") dose after completing the primary vaccination cycle [[1]]. Nonetheless, recent evidence suggests that even the vaccine booster-elicited humoral immunity against SARS-CoV-2 wanes over time, such that the administration of additional booster doses has already been initiated in certain countries, with preliminary evidence of enhanced protection compared to people who have only received a single vaccine booster [[2]]. [Extracted from the article]

Several lines of evidence garnered so far attest that coronavirus disease 2019 (COVID-19) is associated with a remarkably high rate of thrombotic events. [12][13][14][15] These findings are also in keeping with solid evidence of prolonged prothrombin times and decreased platelet counts in COVID-19 patients, especially those progressing to severe/critical illness, as underpinned in most recent meta-analyses. [13] Interestingly, prothrombin time was found to be lower in COVID-19 patients with critical illness compared with those with milder disease, while ETP values were overlapping. Conversely, impaired fibrinolysis measured with rotational thromboelastometry was commonplace in patients severe COVID-19 illness. [Extracted from the article]

This study aimed to investigate whether the temperature of distilled water used for reconstituting lyophilized routine internal quality control (IQC) material may influence the process of validation of analytical sessions of routine hemostasis testing. Routine hemostasis testing was performed for 10 consecutive days using two levels of IQC materials dissolved using distilled water at three different temperatures (2–4°C, 22–24°C and 36–38°C). The tests assayed comprised prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FBG), antithrombin (AT), protein C (PC), protein S (PS) and D-dimer (D-Dimer HS 500), using the same ACL TOP 700 hemostasis instrument. Overall, 50% (i.e. 7/14) IQC measurements displayed statistically significant bias when lyophilized material was dissolved with distilled water at 3–5°C compared to 22–24°C, and in two instances (level I for both PT and D-dimer) the bias was higher than the quality specifications. Concerning lyophilized material dissolved with distilled water at 36–38°C, 21% (3/14) IQC values displayed a statistically significant bias compared to 22–24°C, and in one instance (level 2 for PT) the bias was higher than the quality specifications. The results of this study show that water temperature, as used to dissolve lyophilized IQC material, may represent an important pre-analytical variable in routine hemostasis testing, especially cold temperatures. Laboratory professionals are encouraged to standardize water temperature, preferably between 22 and 24°C, before reconstituting lyophilized IQC materials used to validate routine hemostasis testing. [ABSTRACT FROM AUTHOR]

Keywords: antigen; COVID-19; diagnosis; immunoassay; SARS-CoV-2 EN antigen COVID-19 diagnosis immunoassay SARS-CoV-2 146 148 3 02/07/22 20220201 NES 220201 To the Editor, An important aspect, that has become clear several months since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has begun, is that diagnostic testing is critical for prevention, diagnosis, prognostication and clinical management of coronavirus disease 2019 (COVID-19) [[1]]. The nucleocapsid antigen-antibody complexes are then captured by anti-SARS-CoV-2 antibodies immobilized on the SARS-CoV-2 test line. [Extracted from the article]

The median rate of six month decline of antibodies levels compared to the peak values was 85% (IQR, 80-89%) for anti-SARS-CoV-2 spike trimeric IgG and 93% (IQR, 89-95%) for anti-SARS-CoV-2 RBD IgG, respectively. Keywords: antibodies; COVID-19; immune response; SARS-CoV-2; vaccination EN antibodies COVID-19 immune response SARS-CoV-2 vaccination e29 e31 3 01/07/22 20220115 NES 220115 To the Editor, While novel effective therapies against coronavirus disease 2019 (COVID-19) are being developed and deployed, mass vaccination remains at the heart of national and international campaigns aimed at limiting the spread and the unfavorable consequences of the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic [[1]]. [Extracted from the article]

• Anticipating COVID-19 vaccines' response is essential for predicting effectiveness • Serum antibodies levels correlate between first and second COVID-19 vaccine doses • This association depends on the immunoassay, ranging between 0.40-0.71 Objectives : Reliable evidence suggests that anticipating the humoral response to coronavirus disease 2019 (COVID-19) vaccines is essential for predicting their clinical effectiveness. In this work, we sought to determine the extent to which the response of anti-SARS-CoV-2 antibodies BNT162b2 booster measured with four different commercial immunoassays could be predicted after initial homologous vaccination. Methods : This observational study enrolled 181 SARS-CoV-2 baseline seronegative healthcare workers (mean age 42±13 years; 59.7% females), who received two doses of the BNT162b2 vaccine. Antibodies levels were assessed with Roche Elecsys Anti-SARS-CoV-2 S, ACCESS SARS-CoV-2 IgG II, Snibe S-RBD IgG, and LIAISON SARS-CoV-2 TrimericS IgG. The correlation of anti-SARS-CoV-2 serum antibodies 21 days after the first vaccine dose and 30 days after the second dose was assessed with Pearson's test. Results : A significant correlation was found between serum anti-SARS-CoV-2 antibodies levels after the first (T1) and second (T2) BNT162b2 vaccine dose with all immunoassays, though the strength of such association depended on the immunoassay. Briefly, the highest correlation was found for LIAISON SARS-CoV-2 TrimericS IgG (r=0.71), followed by ACCESS SARS-CoV-2 IgG II (r=0.65), Snibe S-RBD IgG (r=0.52), and then Roche Elecsys Anti-SARS-CoV-2 S (r=0.40). Conclusion : The value of predicting post-booster values of anti-SARS-CoV-2 antibodies levels from pre-booster levels significantly depends on the immunoassay used. [ABSTRACT FROM AUTHOR]

Keywords: antibodies; COVID-19; immune response; SARS-CoV-2; vaccination EN antibodies COVID-19 immune response SARS-CoV-2 vaccination e377 e379 3 09/08/21 20210901 NES 210901 To the Editor, We read with interest the article of Padoan and colleagues [[1]], who thoughtfully assessed the analytical and clinical characteristics of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor binding domain (RBD) IgG chemiluminescent immunoassay recently commercialized by Snibe diagnostics (New Industries Biomedical Engineering Co., Ltd [Snibe], Shenzhen, China). Antibodies, COVID-19, immune response, SARS-CoV-2, vaccination. [Extracted from the article]

Keywords: coronavirus; COVID-19; immunoassay EN coronavirus COVID-19 immunoassay 1156 1159 4 06/15/20 20200701 NES 200701 To the Editor, The recent emergence of 2019 coronavirus disease (COVID-19) in December 2019 in China, and its ensuing widespread propagation all around the world, have finally persuaded the World Health Organization (WHO) to upgrade COVID-19 from an epidemic to a pandemic disease [[1]]. These results are substantially aligned with those previously published using the same immunoassays by Padoan et al. [[5]], and especially by Jin et al. [[9]], who reported that positivity for anti-SARS-CoV-2 IgM and IgG antibodies was 50% and 95% using different CLIAs. Lancet 2020;395:1101-2. 5 Padoan A, Cosma C, Sciacovelli L, Faggian D, Plebani M. Analytical performances of a chemiluminescence immunoassay for 2019-nCov IgM/IgG and antibody kinetics. [Extracted from the article]

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. [ABSTRACT FROM AUTHOR]

Background: This two-center study was designed to verify comparability of procalcitonin (PCT) values among 10 different commercial immunoassays. Methods: A total number of 176 routine lithium-heparin plasma samples were divided in identical aliquots and simultaneously analyzed with 10 different PCT immunoassays, including Kryptor BRAHMS PCT sensitive, Abbott Architect BRAHMS PCT, Beckman Coulter Access PCT (on Access and DXI), BioMérieux Vidas BRAHMS PCT, Diasorin Liaison BRAHMS PCT, Fujirebio Lumipulse G BRAHMS PCT, Roche BRAHMS PCT (on Cobas E801), Diazyme PCT (on Roche Cobas C702) and SNIBE Maglumi PCT. Results: Highly significant correlation was always found across multiple comparisons, with correlation coefficients comprised between 0.918 and 0.997 (all p < 0.001). Bland and Altman plots analysis revealed highly variable bias among immunoassays, ranging between ±0.2% and ±38.6%. Diazyme PCT on Roche Cobas C702 and SNIBE Maglumi PCT displayed the larger overestimation, whilst PCT values were underestimated by Cobas BRAHAMS PCT. The agreement was always >80% (all p < 0.001), but varied largely across multiple comparisons, ranging between 90%–99% at 0.1 μg/L, 81%–99% at 0.25 μg/L, 83%–100% at 0.5 μg/L, 94%–100% at 2.0 μg/L and 90%–99% at 10 μg/L, respectively. The larger disagreement was observed comparing Diazyme PCT and Maglumi PCT with the other methods. Conclusions: Although we found acceptable correlation among 10 commercial PCT immunoassays, the limited agreement at clinical decision thresholds remains a major issue, especially at lower end of PCT concentration, thus potentially contributing to jeopardize the clinical value of this biomarker. [ABSTRACT FROM AUTHOR]

Background: Ethylenediaminetetraacetic acid (EDTA)-dependent pseudothrombocytopenia is a rare phenomenon. Spurious pseudothrombocytopenia has also been described in other circumstances, while artifactual platelet count in whole blood samples anticoagulated with sodium citrate is an exceptional occurrence. Case report: In this study, we describe the case of a 44-year-old ostensibly healthy woman who attended the local outpatient clinic for routine laboratory testing, including platelet count in EDTA and sodium citrate, for suspected artifactual pseudothrombocytopenia previously identified in another center. The results of hematological testing on both specimens were essentially normal, except for mild anemia. Nevertheless, the platelet number was 425 × 109/L in K2EDTA and 266 × 109/L (293 × 109/L after correcting for sample dilution) in sodium citrate, respectively. Microscopic revision of blood smears revealed the presence of platelet aggregates and satellitism only in the sodium citrate specimen. Conclusion: Unlike previous occasional reports of concomitant EDTA- and sodium citrate-dependent pseudothrombocytopenia, we first describe a paradigmatic case of artifactual platelet count attributable to platelet clumping and satellitism, exclusively developing in blood anticoagulated with sodium citrate. [ABSTRACT FROM AUTHOR]

Background: Although accumulating evidence suggests that the hemostatic balance is impaired in patients with hypertriglyceridemia, hyperbilirubinemia or hemolytic anemias, little is known on the underlying biological mechanisms. This experimental study was aimed at exploring whether increasing values of triglycerides, bilirubin or cell-free hemoglobin promote thrombin generation in plasma. Methods: Three different pools were prepared from three different sets of 20 normal routine plasma citrate samples. The native pools were spiked with increasing amounts of exogenous triglycerides (up to 8.8 mmol/L), bilirubin (up to 350 μmol/L) or autologous hemolyzed blood (up to 3.5 g/L cell-free hemoglobin). Using the fully-automated thrombin generation analyzer ST Genesia, we measured the following parameters: lag time (LT), time to peak (TP), peak height (PH) and endogenous thrombin potential (ETP). Results: A sustained increase of PH and ETP was found in parallel with increasing triglyceride concentrations, peaking in the aliquot with 8.8 mmol/L. Conversely, LT and TP displayed an opposite trend, reaching a maximum decrease in the 8.8 mmol/L aliquot. Increasing bilirubin concentrations promoted remarkable increases of PH and ETP and decreases of TP and LT, up to 211 μmol/L. After this threshold, all parameters tended to return towards baseline values. A constant increase of PH and ETP was also noted in hemolyzed samples, peaking in the 3.5 g/L cell-free hemoglobin aliquot, whereas the TP and LT remained unchanged in all hemolyzed aliquots. Conclusions: Our findings suggest that hypertriglyceridemia, hyperbilirubinemia and hemolysis may promote a hypercoagulable state in human plasma. [ABSTRACT FROM AUTHOR]

Introduction: Pediatric tubes are increasingly used for drawing blood for hemostasis testing. This study has investigated the potential impact of low volume citrate tubes on results of first‐line hemostasis testing. Methods: The study population comprised 34 patients on warfarin therapy and 17 ostensibly healthy volunteers. Blood was collected into five different evacuated blood tubes from each subject. On right arm, blood was drawn directly into two standard evacuated blood tubes (3‐mL Vacuette and 2‐mL Vacutest) and one evacuated low volume blood tube (1‐mL Vacuette) by straight needle venipuncture. On left arm, blood was drawn using a 5‐mL syringe and then transferred within two nonevacuated microtubes (0.5 mL MiniCollect and 0.5 mL Micro Test). Prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen were assayed on ACL TOP 700. Results: Spearman's correlation of PT, APTT, and fibrinogen values obtained using different tubes was always satisfactory (ie, ≥0.93). A statistically significant bias was frequently found by comparing values obtained in different tubes. Nevertheless, the minimum quality specifications for bias were exceeded only by comparing data of Vacuette 1 mL with those of all other blood tubes for PT, by comparing data of Micro Test 0.5 mL with those of all other blood tubes for APTT, and by comparing data of Micro Test 0.5‐mL blood tubes with those of Vacuette 3 mL and Vacuette 1. Conclusion: First‐line hemostasis testing using low volume citrate tubes may display differences sometimes exceeding the minimum quality specifications. [ABSTRACT FROM AUTHOR]

Platelets are central elements of hemostasis and also play a pivotal role in the pathogenesis of thrombosis in coronavirus disease 2019. This study was planned to investigate the effects of different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) recombinant spike protein variants on platelet morphology and activation. Citrated whole blood collected from ostensibly healthy subjects was challenged with saline (control sample) and with 2 and 20 ng/mL final concentration of SARS-CoV-2 recombinant spike protein of Ancestral, Alpha, Delta, and Omicron variants. Platelet count was found to be decreased with all SARS-CoV-2 recombinant spike protein variants and concentrations tested, achieving the lowest values with 20 ng/mL Delta recombinant spike protein. The mean platelet volume increased in all samples irrespective of SARS-CoV-2 recombinant spike protein variants and concentrations tested, but especially using Delta and Alpha recombinant spike proteins. The values of both platelet function analyzer-200 collagen-adenosine diphosphate and collagen-epinephrine increased in all samples irrespective of SARS-CoV-2 recombinant spike protein variants and concentrations tested, and thus reflecting platelet exhaustion, and displaying again higher increases with Delta and Alpha recombinant spike proteins. Most samples where SARS-CoV-2 recombinant spike proteins were added were flagged as containing platelet clumps. Morphological analysis revealed the presence of a considerable number of activated platelets, platelet clumps, platelet-monocyte, and platelet-neutrophils aggregates, especially in samples spiked with Alpha and Delta recombinant spike proteins at 20 ng/mL. These results provide support to the evidence that SARS-CoV-2 is capable of activating platelets through its spike protein, though such effect varies depending on different spike protein variants. [ABSTRACT FROM AUTHOR]

Current recommendations advocate that blood tubes for coagulation testing should be filled not less than 90% of their nominal filling volume, since under- or over-filling >10% may generate unreliable results of some hemostasis assays. This study was hence aimed to explore filling accuracy and precision of commercial blood tubes. Between-lot variations of 3 different lots (20 tubes per lot) of 3.2% citrate blood tubes manufactured by Becton Dickinson, Greiner and Kima were studied. One additional lot from each manufacturer was assessed in triplicate (three series of 20 tubes), to assess within-lot variation. All tubes were first weighed empty and then filled with distilled water by a syringe, under ideal filling conditions. Filled tubes were weighed again, in duplicate. For each 20 tubes series, mean bias (deviation from the ideal tube filling volume) and imprecision (coefficient of variation; CV%) were calculated. All biases were within ±10%. Within-lot and between-lot variation in filling volume was acceptable, and comprised between 0.4 and 2.4%. Greiner tubes were the most accurate (bias, -1.0 to 2.4%), followed by Kima (bias, -7.8 to -5.9%) and Becton Dickinson (bias, -9.6 to 3.3%) tubes. The highest between-lot difference was noted for Becton Dickinson tubes (up to 12.9%), followed by Greiner and Kima tubes (up to 3.4 and 1.8%, respectively). Although coagulation tubes filling accuracy was within ±10% for all three tested manufacturers, the overall bias was found to be variable among manufacturers and lots. Major effort shall be made by blood tube manufacturers for improving standardization of their products. [ABSTRACT FROM AUTHOR]

A 51-year old male patient was admitted to the hospital with acute dyspnea and history of chronic asthma. Venous blood was drawn into a 3.0 mL heparinized syringe and delivered to the laboratory for blood gas analysis (GEM Premier 4000, Instrumentation Laboratory), which revealed high potassium value (5.2 mmol/L; reference range on whole blood, 3.5-4.5 mmol/L). This result was unexpected, so that a second venous blood sample was immediately drawn by direct venipuncture into a 3.5 mL lithium-heparin blood tube, and delivered to the laboratory for repeating potassium testing on Cobas 8000 (Roche Diagnostics). The analysis revealed normal plasma potassium (4.6 mmol/L; reference range in plasma, 3.5-5.0 mmol/L) and haemolysis index (5; 0.05 g/L). Due to suspicion of spurious haemolysis, heparinized blood was transferred from syringe into a plastic tube and centrifuged. Potassium and haemolysis index were then measured in this heparinized plasma, confirming high haemolysis index (50; 0.5 g/L) and pseudohyperkalemia (5.5 mmol/L). Investigation of this case revealed that spurious haemolysis was attributable to syringe delivery in direct ice contact for ~15 min. This case emphasizes the importance of avoiding sample transportation in ice and the need of developing point of care analysers equipped with interference indices assessment. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction: Liquid chromatography coupled to atmospheric pressure ionization tandem mass spectrometry (LC-ESI-MS/MS) is currently considered the reference method for quantitative determination of urinary free cortisol (UFC). One of the major drawbacks of this measurement is a particular form of matrix effect, conventionally known as ion suppression. Materials and methods: We describe here the case of a 66-year-old-patient referred to the daily service of general medicine for intravenous antibiotic administration due to a generalized Staphylococcus aureus infection and for routine 24 hours UFC monitoring in the setting of glucocorticoid replacement therapy. Results: The observation of 10-fold decrease of internal standard of cortisol signal led us to hypothesize the presence of an ion suppression effect due to a co-eluting endogenous compound. Screening analysis of tandem mass spectrometry (MS/MS) spectra of the interfering molecule, along with in vitro confirmation analyses, were suggestive of the presence of high concentration of piperacillin. The problem was then easily solved with minor modifications of the chromatographic technique. Conclusions: According to our findings, antibiotic therapy with piperacillin/tazobactam should be regarded as an important interference in UFC assessment, which may potentially affect detection capability, precision and accuracy of this measurement. This case report emphasizes that accurate anamnesis and standardization of all phases of urine collection are essential aspects for preventing potential interference in laboratory testing. [ABSTRACT FROM AUTHOR]

Growth differentiation factor-15 (GDF-15) has recently emerged as a strong and independent predictor of cardiovascular events and mortality. However, the pathophysiological mechanisms underlying this important association remain speculative. This study was aimed to investigate the potential associations between the serum concentration of GDF-15 and clinical or laboratory parameters in a population of ostensibly healthy subjects. The study population consisted of 44 healthy volunteers enrolled from the laboratory staff (14males and 30 females;mean age, 47±11 years), who had their blood collected for assessing complete blood cell count, GDF-15, serum creatinine, albumin, cardiac troponin T, galectin-3, routine coagulation tests, D-dimer, von Willebrand factor and platelet function testing using platelet function analyzer- 100. In univariate analysis, serum GDF-15 was found to be positively associated with age and plasma fibrinogen and negatively associated with renal function and collagenepinephrine (CEPI). In multiple linear regression analysis, serum GDF-15 remained significantly associated with renal function, CEPI and plasma fibrinogen. Healthy subjects with GDF-15 above the median value had a twofold probability of displaying shorter CEPI closure times. Taken together, these results suggest that higher serum values of GDF-15 may be associated with overall global platelet hyperactivity and increased plasma fibrinogen, so providing another plausible explanation for the association between GDF-15, cardiovascular events, and mortality. [ABSTRACT FROM AUTHOR]

The use of liquid chromatography-mass spectrometry (LC-MS) for both diagnostics and research purposes is rapidly growing in clinical laboratories. As for more conventional areas of in vitro diagnostic testing, many preanalytical variables have an impact on these techniques and may hence jeopardize the quality of tests results. The leading preanalytical variables include patient preparation, the nature of the blood collection tubes and additives, interference from spurious hemolysis, sample handling and management, composition of blood tubes, contamination, as well as storage conditions. Therefore, the aim of this article is provide a narrative overview about the leading preanalytical issues which may ultimately influence LC-MS testing of human blood samples, and provide tentative indications, as for current evidence, about optimal preanalytical management of blood samples for proteomics and metabolomics studies. These general recommendations entail pre-storage centrifugation, use of appropriate tubes and additives, addition of bacteriostatic preservatives, enrichment and purification of samples, elimination of unsuitable specimens, rapid analysis or immediate storage at − 70 °C, and avoidance of analyzing frozen-thawed specimens. [ABSTRACT FROM AUTHOR]

Background: Although the clinical significance of measuring bile acids concentration in plasma or serum has been recognized for long in patients with hepatobiliary disease and/or bile acid malabsorption, the reference separation techniques are expensive and mostly unsuitable for early diagnosis and for measuring large volumes of samples. Therefore, this study was aimed to evaluate the analytical performance of three commercial enzymatic techniques for measuring total bile acids in plasma using a fully-automated clinical chemistry platform. Methods: Three commercial enzymatic assays (from Diazyme, Randox and Sentinel) were adapted for use on a Cobas Roche c501. We performed imprecision and linearity studies, and we compared results with those obtained using a reference liquid chromatography-mass spectrometry (LC-MS) technique on an identical set of lithium-heparin plasma samples. Results: Total imprecision was optimal, always equal or lower than 3%. All assays had optimal linearity between 3–138 μmol/L. The comparison studies showed good correlation with LC-MS data (Spearman’s correlation coefficients always >0.92), but all plasma samples values were significantly underestimated using the commercial enzymatic assays (-44% for Diazyme, -16% for Randox and -12% for Sentinel). The agreement at the 10 and 40 μmol/L diagnostic thresholds of total bile acids in plasma ranged between 86–92%. This discrepancy was found to be mainly attributable to a heterogeneous composition in terms of bile acids content of the three assay calibrators. Conclusions: This study suggests that the analytical performance of the three commercial enzymatic assays is excellent, thus confirming that automation of this important test by means of enzymatic assessment may be feasible, practical, reliable and supposedly cheap. Nevertheless, the underestimation of values compared to the reference LC-MS also suggests that the local definition and validation of reference ranges according to the combination between the specific enzymatic assay and the different clinical chemistry platforms may be advisable. [ABSTRACT FROM AUTHOR]

Background: The blood to anticoagulant ratio is standardized according to the physiological calcium concentration in blood samples conventionally used for hemostasis testing. Specifically, one fixed volume of 0.109 mmol/L sodium citrate is added to 9 volumes of blood. Since little is known about the impact of hypercalcemia on the calcium-binding capacity of citrate, this study was planned to investigate the effect of experimental hypercalcemia on routine hemostasis testing. Methods: Fifteen pooled citrated plasmas with matching lithium-heparin pooled plasma from patients with different values of prothrombin time (PT) were divided in three aliquots of 0.6mL each. The first paired aliquots of both citrate and lithium-heparin plasma were supplemented with 60μL of saline, the second paired aliquots with 30μL of saline and 30μL of calcium chloride and the third paired aliquots with 60μL of calcium chloride. Total and ionized calcium was measured in all aliquots of citrate and lithium-heparin plasma, whereas PT, activated partial thromboplastin time (APTT) and fibrinogen were measured in citrate plasma aliquots. Results: Total calcium concentration gradually increased in both lithium-heparin and citrate plasma aliquots 2 and 3 compared to baseline aliquot 1. The concentration of ionized calcium also gradually increased in lithium-heparin plasma aliquots 2 and 3, whereas it remained immeasurable (i.e., <0.10 mmol/L) in all citrate plasma aliquots. No significant differences were observed for values of PT, APTT and fibrinogen in citrate plasma aliquots 2 and 3 compared to the baseline aliquot 1, with a mean bias was always comprised within the desirable quality specifications derived from biological variability data. Conclusion: Hypercalcemia, up to severe hypercalcemia does not generate significant bias in results of first-line coagulations tests, so that hypothetical consideration of adjusting citrate-blood ratio is unjustified in hypercalcemic patients. [ABSTRACT FROM AUTHOR]

Background: Recent evidence suggests that red blood cell distribution width (RDW), a simple measure of anisocytosis, may predict the risk of adverse clinical outcomes in both the general population and in patients with severe pathologies. Since it was also shown that the birth season influences the lifetime disease risk, this study was aimed to investigate whether an association may exist between adult RDW values and birth season. Methods: The study population consisted in healthy Caucasian blood donors aged 18 or older, undergoing routine laboratory testing before regular blood donation. Results: Overall, 6122 healthy blood donors were included in this study (median age 41 years; 1807 women and 4315 men). Age, sex, mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) but not hemoglobin and hematocrit were found to be independent predictors of RDW. When the study population was classified according to birth season, a significant difference was found for RDW values, but not for age, sex, hemoglobin, hematocrit, MCV and MCH. Subjects born in spring exhibited RDW values generally higher compared to those born in other seasons, reaching statistical significance when compared to those born in summer and winter. In particular, subjects born in spring had a 33% (p = 0.014) higher probability of displaying increased RDW values in adulthood compared to those with summer birth. Conclusions: Despite additional studies that are needed to confirm these original findings, the evidence that a significant link exists between birth season and adult anisocytosis provides a plausible explanation for the association between birth season and lifetime disease risk. [ABSTRACT FROM AUTHOR]

Background: The measurement of 25OH vitamin D continues to grow in clinical laboratories. The aim of this multicenter study was to compare the results of seven automated commercial immunoassays with a reference HPLC technique. Methods: One hundred and twenty consecutive outpatient serum samples were centrifuged, divided in aliquots, frozen and shipped to the participating laboratories. 25OH Vita - min D was measured with a reference HPLC system and with seven automated commercial immunoassays (Roche Cobas E601, Beckman Coulter Unicel DXI 800, Ortho Vitros ES, DiaSorin Liaison, Siemens Advia Centaur, Abbott Architect i System and IDS iSYS). Results: Compared to the reference method, the regression coefficients ranged from 0.923 to 0.961 (all p<0.001). The slope of Deming fit ranged from 0.95 to 1.06, whereas the intercept was comprised between -15.2 and 9.2 nmol/L. The bias from the reference HPLC technique varied from 14.5 to 8.7 nmol/L. The minimum performance goal for bias was slightly exceeded by only one immunoassay. The agreement between HPLC and the different immunoassays at 50 nmol/L 25OH Vitamin D varied between 0.61 and 0.85 (all p<0.001). The percentage of samples below this cut-off was significantly different with only one immunoassay. Conclusions: The excellent correlation with the reference HPLC technique attests that all seven automated immuno - assays may be reliably used for routine assessment of 25OH-D in clinical laboratories. The significant bias among the different methods seems mostly attributable to the lack of standardization and calls for additional efforts for improving harmonization of 25OH-D immunoassays. [ABSTRACT FROM AUTHOR]

The red blood cell distribution width (RDW) is a simple and inexpensive parameter, which reflects the degree of heterogeneity of erythrocyte volume (conventionally known as anisocytosis), and is traditionally used in laboratory hematology for differential diagnosis of anemias. Nonetheless, recent evidence attests that anisocytosis is commonplace in human disorders such as cardiovascular disease, venous thromboembolism, cancer, diabetes, community-acquired pneumonia, chronic obstructive pulmonary disease, liver and kidney failure, as well as in other acute or chronic conditions. Despite some demographic and analytical issues related to the routine assessment that may impair its clinical usefulness, an increased RDW has a high negative predictive value for diagnosing a variety of disorders, but also conveys important information for short- and long-term prognosis. Even more importantly, the value of RDW is now being regarded as a strong and independent risk factor for death in the general population. Although it has not been definitely established whether an increased value of RDW is a risk factor or should only be considered an epiphenomenon of an underlying biological and metabolic imbalance, it seems reasonable to suggest that the assessment of this parameter should be broadened far beyond the differential diagnosis of anemias. An increased RDW mirrors a profound deregulation of erythrocyte homeostasis involving both impaired erythropoiesis and abnormal red blood cell survival, which may be attributed to a variety of underlying metabolic abnormalities such as shortening of telomere length, oxidative stress, inflammation, poor nutritional status, dyslipidemia, hypertension, erythrocyte fragmentation and alteration of erythropoietin function. As such, the aim of this article is to provide general information about RDW and its routine assessment, to review the most relevant implications in health and disease and give some insights about its potential clinical applications. [ABSTRACT FROM AUTHOR]

Background: This study was planned to investigate whether serum α-amylase concentration may be associated with running performance, physiological characteristics and other clinical chemistry analytes in a large sample of recreational athletes undergoing distance running. Methods: Forty-three amateur runners successfully concluded a 21.1 km half-marathon at 75%–85% of their maximal oxygen uptake (VO2max). Blood was drawn during warm up and 15 min after conclusion of the run. Results: After correction for body weight change, significant post-run increases were observed for serum values of alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, bilirubin, creatine kinase (CK), iron, lactate dehydrogenase (LDH), triglycerides, urea and uric acid, whereas the values of body weight, glomerular filtration rate, total and low density lipoprotein-cholesterol were significantly decreased. The concentration of serum α-amylase was unchanged. In univariate analysis, significant associations with running performance were found for gender, VO2max, training regimen and pre-run serum values of α-amylase, CK, glucose, high density lipoprotein-cholesterol, LDH, urea and uric acid. In multivariate analysis, only VO2max (p = 0.042) and baseline α-amylase (p = 0.021) remained significant predictors of running performance. The combination of these two variables predicted 71% of variance in running performance. The baseline concentration of serum α-amylase was positively correlated with variation of serum glucose during the trial (r = 0.345; p = 0.025) and negatively with capillary blood lactate at the end of the run (r = -0.352; p = 0.021). Conclusions: We showed that the baseline serum α-amylase concentration significantly and independently predicts distance running performance in recreational runners. [ABSTRACT FROM AUTHOR]

Background To investigate the influence of different phlebotomy postures on clinical chemistry testing. Materials and methods Nineteen volunteers were recruited from the laboratory staff. A first set of samples was drawn after 25 min of resting in supine position, a second after 20 min in sitting position, and a third after 20 min in upright position. Clinical chemistry testing was performed on Roche Cobas C501. Results The plasma volume change (PVC) was − 3.4% from supine to sitting, − 14.1% from supine to standing and − 9.7% from sitting to standing. Compared to quality specifications for bias, hemoglobin, hematocrit, albumin and total proteins exhibited meaningful increases from supine to sitting, whereas meaningful increases were observed for hemoglobin, hematocrit, albumin, alkaline phosphatase (ALP), amylase, aspartate aminotransferase (AST), total bilirubin, calcium, total and high-density lipoprotein (HDL) cholesterol, gamma-glutamyl transferase (GGT), glucose, lactate dehydrogenase (LDH), magnesium, total protein and triglycerides from sitting to standing. The parameters with meaningful bias from sitting to upright were hemoglobin, hematocrit, albumin, ALP, total bilirubin, calcium, total and HDL cholesterol, glucose, LDH and total protein. Conclusions These results provide further support to the need of standardizing patient's posture during phlebotomy. [ABSTRACT FROM AUTHOR]

Background: Running economy and performance in middle distance running depend on several physiological factors, which include anthropometric variables, functional characteristics, training volume and intensity. Since little information is available about hematological predictors of middle distance running time, we investigated whether some hematological parameters may be associated with middle distance running performance in a large sample of recreational runners. Methods: The study population consisted in 43 amateur runners (15 females, 28 males; median age 47 years), who successfully concluded a 21.1 km half-marathon at 75–85% of their maximal aerobic power (VO2max). Whole blood was collected 10 min before the run started and immediately thereafter, and hematological testing was completed within 2 hours after sample collection. Results: The values of lymphocytes and eosinophils exhibited a significant decrease compared to pre-run values, whereas those of mean corpuscular volume (MCV), platelets, mean platelet volume (MPV), white blood cells (WBCs), neutrophils and monocytes were significantly increased after the run. In univariate analysis, significant associations with running time were found for pre-run values of hematocrit, hemoglobin, mean corpuscular hemoglobin (MCH), red blood cell distribution width (RDW), MPV, reticulocyte hemoglobin concentration (RetCHR), and post-run values of MCH, RDW, MPV, monocytes and RetCHR. In multivariate analysis, in which running time was entered as dependent variable whereas age, sex, blood lactate, body mass index, VO2max, mean training regimen and the hematological parameters significantly associated with running performance in univariate analysis were entered as independent variables, only MPV values before and after the trial remained significantly associated with running time. After adjustment for platelet count, the MPV value before the run (p = 0.042), but not thereafter (p = 0.247), remained significantly associated with running performance. Conclusion: The significant association between baseline MPV and running time suggest that hyperactive platelets may exert some pleiotropic effects on endurance performance. [ABSTRACT FROM AUTHOR]

Background: Presently the necessity of fasting time for coagulation tests is not standardized. Our hypothesis is that this can harm patient safety. This study is aimed at evaluating whether a light meal (i.e. breakfast) can jeopardize laboratory coagulation tests. Materials and methods: A blood sample was firstly collected from 17 fasting volunteers (12 h). Immediately after blood collection, the volunteers consumed a light meal. Then samples were collected at 1, 2 and 4 h after the meal. Coagulation tests included: activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fbg), antithrombin III (AT), protein C (PC) and protein S (PS). Differences between samples were assessed by Wilcoxon ranked-pairs test. The level of statistical significance was set at P < 0.05. Mean % differences were determined and differences between and baseline and 1, 2 and 4h samples were compared with reference change value (RCV). Results: A significantly higher % activity of AT was observed at 1 h and 4 h after meal vs. baseline specimen [113 (104-117) and 111 (107-120) vs. 109 (102-118), respectively; P = 0.029 and P = 0.016]. APTT at 2 h was found significantly lower than baseline samples [32.0 (29.9-34.8) vs. 34.1 (32.2-35.2), respectively; P = 0.041]. The results of both Fbg and PS tests were not influenced by a light meal. Furthermore, no coagulation tests had significant variation after comparison with RCV. Conclusion: A light meal does not influence the laboratory coagulation tests we assessed, but we suggest that the laboratory quality managers standardize the fasting time for all blood tests at 12 hours, to completely metabolize the lipids intake. [ABSTRACT FROM AUTHOR]

Int roduction: The contamination of serum or lithium heparin blood with ethylenediaminetetraacetic acid (EDTA) salts may affect accuracy of some critical analytes and jeopardize patient safety. The aim of this study was to evaluate the effect of lithium heparin sample contamination with different amounts of K2EDTA. Materials and methods: Fifteen volunteers were enrolled among the laboratory staff. Two lithium heparin tubes and one K2EDTA tube were collected from each subject. The lithium-heparin tubes of each subject were pooled and divided in 5 aliquots. The whole blood of K2EDTA tube was then added in scalar amount to autologous heparinised aliquots, to obtained different degrees of K2EDTA blood volume contamination (0%; 5%; 13%; 29%; 43%). The following clinical chemistry parameters were then measured in centrifuged aliquots: alanine aminotranspherase (ALT), bilirubin (total), calcium, chloride, creatinine, iron, lactate dehydrogenase (LD), lipase, magnesium, phosphate, potassium, sodium. Results: A significant variation starting from 5% K2EDTA contamination was observed for calcium, chloride, iron, LD, magnesium (all decreased) and potassium (increased). The variation of phosphate and sodium (both increased) was significant after 13% and 29% K2EDTA contamination, respectively. The values of ALT, bilirubin, creatinine and lipase remained unchanged up to 43% K2EDTA contamination. When variations were compared with desirable quality specifications, the bias was significant for calcium, chloride, LD, magnesium and potassium (from 5% K2EDTA contamination), sodium, phosphate and iron (from 29% K2EDTA contamination). Conclusions: The concentration of calcium, magnesium, potassium, chloride and LD appears to be dramatically biased by even modest K2EDTA contamination (i.e., 5%). The values of iron, phosphate, and sodium are still reliable up to 29% K2EDTA contamination, whereas ALT, bilirubin, creatinineand lipase appear overall less vulnerable towards K2EDTA contamination. [ABSTRACT FROM AUTHOR]

Background This study was planned to establish whether random orientation of gel tubes after centrifugation may impair sample quality. Materials and methods Eight gel tubes were collected from 17 volunteers: 2 Becton Dickinson (BD) serum tubes, 2 Terumo serum tubes, 2 BD lithium heparin tubes and 2 Terumo lithium heparin tubes. One patient's tube for each category was kept in a vertical, closure-up position for 90 min ("upright"), whereas paired tubes underwent bottom-up inversion every 15 min, for 90 min ("inverted"). Immediately after this period of time, 14 clinical chemistry analytes, serum indices and complete blood count were then assessed in all tubes. Results Significant increases were found for phosphate and lipaemic index in all inverted tubes, along with AST, calcium, cholesterol, LDH, potassium, hemolysis index, leukocytes, erythrocytes and platelets limited to lithium heparin tubes. The desirable quality specifications were exceeded for AST, LDH, and potassium in inverted lithium heparin tubes. Residual leukocytes, erythrocytes, platelets and cellular debris were also significantly increased in inverted lithium heparin tubes. Conclusions Lithium heparin gel tubes should be maintained in a vertical, closure-up position after centrifugation. [ABSTRACT FROM AUTHOR]

Background: The IFCC Task Force on Clinical Applications of Cardiac Biomarkers currently recommends evaluation of all troponin immunoassays within the same population to compare their performance. Hence, we planned a multicenter study to compare the four most widespread contemporary sensitive troponin I (TnI) methods. Methods: Seventy-six serum samples were centrifuged, separated and divided in 5 aliquots. The first aliquot was used for clinical measurement, whereas the rest were shipped to participating laboratories, where they were simultaneously thawed. High-sensitivity troponin T (HS-TnT) was measured on a Roche Cobas, whereas TnI was assessed with the Ortho Vitros cTnI, Beckman Coulter DXI 800 AccuTnI, Siemens Vista cTnI and Abbott Architect STAT cTnI. Results: A substantial bias was found between TnI and HSTnT values. Although the correlation was acceptable and comprised between 0.86-0.89, the agreement of diagnostic values was poor, with the kappa statistic always lower than 0.50. Although the direct comparison between the four contemporary sensitive TnI immunoassays generated more favourable results, with Pearson's correlations greater than 0.970 and the kappa statistic equal to or higher than 0.59, we observed wide 95% confidence intervals, significant bias and large dispersion of values, with a single notable exception (i.e., Vitros cTnI versus DXI 800 AccuTnI). Conclusions: The results of this study attest that substantial discrepancies still exist among contemporary sensitive TnI immunoassays. The presence of random variation rather than constant bias appears to be the major contributor to this variance, thus precluding the interchangeability of methods and making the objective of harmonization a rather long and challenging enterprise. [ABSTRACT FROM AUTHOR]

Background: The leading mechanisms responsible for the most prevalent and serious cardiac injuries include myocardiocyte stretch, myocardiocyte necrosis and cardiac fibrosis, which can now be reliably mirrored by measurement of natriuretic peptides, cardiospecific troponins and galectin-3, respectively. Although a large amount of knowledge has been gathered about the behavior and clinical significance of these biomarkers in patients with cardiac disorders, less information is available on their biology in paraphysiological conditions, including high-intensity endurance exercise. Methods: The study population consisted of 18 trained athletes, who performed a 60-km ultramarathon run. Blood was collected before the run (i.e., 'baseline') and immediately after the end of the ultramarathon ('post-marathon') for measurement of serum high-sensitivity troponin I (TnI), NT-proBNP and galectin-3. Results: The concentration of all biomarkers measured in the post-marathon samples was remarkably increased as compared with the values obtained on baseline specimens. In particular, the median increase was 3.3 for TnI, 3.5 for NT-proBNP and 2.4 for galectin-3, respectively. The frequency of values exceeding the diagnostic threshold did not differ at baseline and after the ultramarathon for TnI (6% vs. 25%; p=0.15), instead was significantly increased for NT-proBNP (0% vs. 28%; p=0.016) and galectin-3 (0% vs. 67%; p<0.001). No significant correlation was found among the increase of any of the three biomarkers. Conclusions: The results of this study demonstrate that high-intensity endurance exercise is associated with biochemical abnormalities that may reflect adverse consequences on cardiac structure and biology. [ABSTRACT FROM AUTHOR]

Although physical exercise strongly influences several laboratory parameters, data about the hematological changes after medium distance running are scarce. We studied 31 middle-trained athletes (mean training regimen 217 ± 32 min/week) who performed a 21.1 km, half-marathon run. Blood samples were collected before the run, at the end, and 3 and 20 hours thereafter. The complete blood count was performed on Advia 2120 and included red blood cell (RBC), reticulocyte, and platelet counts; hemoglobin; mean corpuscular volume (MCV); mean corpuscular hemoglobin (MCH); reticulocyte haemoglobin content (Ret CHR); RBC distribution width (RDW),mean platelet volume (MPV).No significant variationswere observed for MCH and Ret CHR. The RBC, reticulocyte, and hemoglobin values modestly decreased after the run. The MCV significantly increased at the end of running but returned to baseline 3 hours thereafter. The RDW constantly increased, reaching a peak 20 hours after the run. The platelet count and MPV both increased after the run and returned to baseline 3 hours thereafter. These resultsmay have implications for definition of reference ranges and antidoping testing, and may also contribute to explaining the relationship between endurance exercise and mortality, since previous studies reported that RDWand MPV may be significantly associated with cardiovascular disease. [ABSTRACT FROM AUTHOR]

Background: It is still uncertain whether or not avoidance to let disinfectant alcohol dry at the site of venipuncture is a source of spurious hemolysis when drawing venous blood. Methods: In a consecutive series of 52 outpatients referred for routine laboratory testing, venous blood was drawn by direct venipuncture with (odd group) or without (pair group) wiping 70% isopropyl alcohol at the site of venipuncture. A 3.5 mL evacuated tube with clot activator and gel separator was drawn from a vein of the upper limb, serum was immediately separated with standard centrifugation and tested for potassium, lactate dehydrogenase (LD), aspartate aminotransferase (AST) and hemolysis index (HI) on Roche Cobas. Results: No specimen was discarded for unsatisfactory venipuncture. No differences for age and gender were observed between groups. As regards the four parameters investigated, no significant differences could be observed between patients in whom blood was drawn with or without letting the alcohol dry. It is also noteworthy that no sample in both groups exceeded the conventional sample rejection threshold of cell-free hemoglobin. Conclusions: The results of our prospective, randomized study attest that failure to wipe alcohol at the site of venipuncture should not be considered as a potential source of spurious hemolysis when drawing blood. [ABSTRACT FROM AUTHOR]

The article reports that reporting the immune response anti-SARS-CoV-2 IgG against the receptor binding domain (RBD) spike protein in healthcare workers. Topics include risk of infection and poor outcomes seem dependent on efficient anti-SARSCoV-2 IgA response; and healthcare workers undergoing vaccination with BNT162b2 mRNA COVID-19 at Peschiera del Garda hospital (Italy).

Preanalytical activities, especially those directly connected with blood sample collection and handling, are the most vulnerable steps throughout the testing process. The receipt of unsuitable samples is commonplace in laboratory practice and represents a serious problem, given the reliability of test results can be adversely compromised following analysis of these specimens. The basic criteria for an appropriate and safe venipuncture are nearly identical to those used for collecting blood for clinical chemistry and immunochemistry testing, and entail proper patient identification, use of the correct technique, as well as appropriate devices and needles. There are, however, some peculiar aspects, which are deemed to be particularly critical when collecting quality specimens for clot-based tests, and these require clearer recognition. These include prevention of prolonged venous stasis, collection of nonhemolyzed specimens, order of draw, and appropriate filling and mixing of the primary collection tubes. All of these important preanalytical issues are discussed in this article, and evidence-based suggestions as well as recommendations on how to obtain a high-quality sample for coagulation testing are also illustrated.We have also performed an investigation aimed to identify variation of test results due to underfilling of primary blood tubes, and have identified a clinically significant bias in test results when tubes are drawn at less than 89% of total fill for activated partial thromboplastin time, less than 78% for fibrinogen, and less than 67% for coagulation factor VIII, whereas prothrombin time and activated protein C resistance remain relatively reliable even in tubes drawn at 67% of the nominal volume. [ABSTRACT FROM AUTHOR]

The more traditional, widespread and practiced method for interpreting the laboratory results is based on the comparison made with reference intervals. Nevertheless, the creation of appropriate reference intervals requires careful planning, monitoring and documentation of every aspect of the study, including the selection of the reference population (encompassing selection of homogeneous groups of reference according to ethnicity, geographical origin and environmental conditions, stratification according to age and gender, definition of health status) along with the use of the most appropriate statistical tools. In the very next future, the longitudinal comparison of laboratory results might probably replace the current use of reference intervals. [ABSTRACT FROM AUTHOR]

Anticoagulants are used to prevent clot formation both in vitro and in vivo. In the specific field of in vitro diagnostics, anticoagulants are commonly added to collection tubes either to maintain blood in the fluid state for hematological testing or to obtain suitable plasma for coagulation and clinical chemistry analyses. Unfortunately, no universal anticoagulant that could be used for evaluation of several laboratory parameters in a sample from a single test tube is available so far. Ethylenediamine tetraacetic acid (EDTA) is a polyprotic acid containing four carboxylic acid groups and two amine groups with lone-pair electrons that chelate calcium and several other metal ions. Calcium is necessary for a wide range of enzyme reactions of the coagulation cascade and its removal irreversibly prevents blood clotting within the collection tube. Historically, EDTA has been recommended as the anticoagulant of choice for hematological testing because it allows the best preservation of cellular components and morphology of blood cells. The remarkable expansion in laboratory test volume and complexity over recent decades has amplified the potential spectrum of applications for this anticoagulant, which can be used to stabilize blood for a variety of traditional and innovative tests. Specific data on the behavior of EDTA as an anticoagulant in hematology, including possible pitfalls, are presented. The use of EDTA for measuring cytokines, protein and peptides, and cardiac markers is described, with an outline of the protection of labile molecules provided by this anticoagulant. The use of EDTA in proteomics and in general clinical chemistry is also described in comparison with other anticoagulants and with serum samples. Finally, the possible uses of alternative anticoagulants instead of EDTA and the potential use of a universal anticoagulant are illustrated. Clin Chem Lab Med 2007;45:565–76. [ABSTRACT FROM AUTHOR]