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Objective: The evaluation of innovative biomarkers of myocardial damage in the perioperative period.Methods: Twenty-four patients with gastric or colorectal cancer were studied and samples were collected for the measurement of myoglobin, troponin I (cTnI), creatine kinase isoenzyme MB (CK-MB), glycogen phosphorylase isoenzyme BB (GPBB), carbonic anhydrase III (CA III), fatty acid-binding protein (FABP), and CK presurgery and on the first, seventh, and thirtieth days post-surgery.Results: Troponin I values were unchanged throughout the study period. Myoglobin, GPBB, CA III, and FABP were significantly increased on day 1 after surgery. On the seventh day, GPBB, myoglobin, and FABP were still increased, whereas CK was decreased. Thirty days after surgery no significant variations were observed except a decrease of CK and CA III.Conclusions: These results show cTnI and CK-MB are unaffected by surgery, while the measurement of CA III, FABP, GPBB, and myoglobin might be unsuitable for diagnosing an acute coronary syndrome perioperatively. [ABSTRACT FROM AUTHOR]

Background: Centrifugation time is a major bottleneck in laboratory specimen throughput. In most cases, 10 minutes is suggested to centrifuge samples on a swing-out rotor centrifuge, at room temperature, with a relative centrifugal force of 1,200+/-100 g and 1,300 g or centrifugation times longer than 10 to 15 minutes may be advisable to get a better platelet clearance. Nevertheless, there is little evidence supporting the influence of different centrifuge times for primary lithium-heparin tubes with plasma separator on stat clinical chemistry testing.Methods: Five evacuated tubes collected from 10 consecutive subjects were centrifuged on an identical swing bucket centrifuge at 1,200 g for 1, 2, 5, 10, and 15 minutes respectively and tested for clinical chemistry stat analytes.Results: Statistically significant variations from the 15-minute centrifuge reference specimen were observed for ALT, calcium, glucose, potassium, urea nitrogen, and CK-MB (1 minute centrifugation), ALT, glucose, urea nitrogen, and CK-MB (2 minutes centrifugation), and glucose (5 and 10 minutes centrifugation). Meaningful biases according to the analytical quality specifi-cations for clinically-allowable variance were recorded for ALT, calcium, glucose, potassium (1 minute centrifugation), and for ALT, glucose, and potassium (2 minutes centrifugation).Conclusion: We confirm that a 10-minute centrifugation time at 1,200 g on a swing bucket centrifuge for samples collected in plastic tubes with a plasma separator may be suitable for stat clinical chemistry testing. [ABSTRACT FROM AUTHOR]

Background: Due to limitations of reference methods, it is recommended to estimate glomerular filtration rate (GFR) by serum creatinine-based equations. The purpose of this study was to assess the correlation between the Modification of Diet in Renal Disease (MDRD) formula and the new 'Mayo Clinic Quadratic' (MCQ) equation. Methods Cumulative results for serum creatinine were retrospectively analyzed in 8,388 outpatients. Results: A significant correlation was observed between the MDRD and MCQ estimates; however, a greater disparity of values, and a less satisfactory correlation, was observed between the 2 equations in subjects with MDRD estimates of GFR >60 mL/min per 1.73 m2. The prevalence of subjects with abnormal GFR values was also significantly different when calculated with either formula. Conclusion: Our results support the hypothesis the new MCQ equation may be a step toward accurately estimating GFR when the diagnosis of chronic kidney disease is unknown. [ABSTRACT FROM AUTHOR]

Background: Although it is recommended that primary tubes containing an additive should be mixed several times, there is no evidence that unmixed specimens will provide unreliable results in hematological testing.Methods: Three primary 3.0-mL siliconized vacuum tubes containing 5.4 mg K2 ethylene diamine tetraacetic acid (EDTA) were sequentially collected from 20 healthy volunteers. The first was not inverted, was left standing in a vertical position, and then analyzed. The second and third tubes were respectively inverted 6 and 12 times immediately after collection and then analyzed.Results: When compared with the reference specimens inverted 6 times, results on unmixed specimens revealed significant decreases for red blood cell count, hemoglobin, hematocrit and platelets count, whereas the mean platelet volume was significantly increased. In none of the specimens were results flagged for platelet clumping, nor did the differences exceed the acceptable limits of bias.Conclusion: Provided the tubes are filled to their nominal volume, the blood-to-anticoagulant mixture occurring during sample collection may be adequate. [ABSTRACT FROM AUTHOR]

The immunoassays methods need avoiding interferences that can influence result interpretation. Main sources of interference arise from either patient status, preparation and physiology or laboratory process and procedures. The aim of this non-systematic critical review is to highlight the preanalytical interferences on laboratory immunoassays. Blood hormone profile changes according with age and depending on sex: these are important variables, mainly in newborn, during both sexual maturation and childbearing. Gonadotropins FSH and LH show a sharp increase with age in females, whereas in males LH appears rather stable. With age both males and females show progressive decay of the hormone profile. Stress causes variations, as it influences GH, prolactin, Cortisol and the total/free ratio of thyroid hormone. Diurnal variations, day of cycle, influence by estrogens on thyroid hormone are relevant for result variability. Paraproteins and autoantibodies can interfere in some assays particularly drug, vitamin D and thyroid hormone. As regards the variables due to sample matrix, and to evacuated tubes components, some additives and anticoagulants have been reported to influence specific assays, e.g. thyroid hormone. Hemolysis, lipemia and bilirubin cause interferences on specific techniques/tests, e.g. ferritin, TSH, Vitamin B12, progesterone and folic acid. Nicotine and cocaine addictions interfere with some hormones. Thus, laboratory professionals should be aware of preanalytical problems particularly important when dealing with the immunoassays, by taking appropriate actions to avoid any relevant interferences., (Copyright © 2020 International Federation of Clinical Chemistry and Laboratory Medicine (IFCC). All rights reserved.)

The constrained economic context leads laboratories to centralize their routine analyses on high-throughput platforms, to which blood collection tubes are sent from peripheral sampling sites that are sometimes distantly located. Providing biochemistry results as quickly as possible implies to consolidate the maximum number of tests on a minimum number of blood collection tubes, mainly serum tubes and/or tubes with anticoagulants. However, depending on the parameters and their pre-analytical conditions, the type of matrix - serum or plasma - may have a significant impact on results, which is often unknown or underestimated in clinical practice. Importantly, the matrix-related effects may be a limit to the consolidation of analyses on a single tube, and thus must be known by laboratory professionals. The purpose of the present critical review is to put forward the main differences between using serum and plasma samples on clinical biochemistry analyses, in order to sensitize laboratory managers to the need for standardization. To enrich the debate, we also provide an additional comparison of serum and plasma concentrations for approximately 30 biochemistry parameters. Properties, advantages, and disadvantages of serum and plasma are discussed from a pre-analytical standpoint - before, during, and after centrifugation - with an emphasis on the importance of temperature, delay, and transport conditions. Then, differences in results between these matrices are addressed for many classes of biochemistry markers, particularly proteins, enzymes, electrolytes, lipids, circulating nucleic acids, metabolomics markers, and therapeutic drugs. Finally, important key-points are proposed to help others choose the best sample matrix and guarantee quality of clinical biochemistry assays. Moreover, awareness of the implications of using serum and plasma samples on various parameters assayed in the laboratory is an important requirement to ensure reliable results and improve patient care.

Background: Prevention of a disturbance of the blood vessel allows phlebotomists to collect a blood specimen by venipuncture that will truly mirror the patient condition. This study was aimed to evaluate the impact of repeated fist clenching and maintenance of the fist during blood collection by venipuncture for routine hematology testing., Methods: Blood were collected from 16 healthy volunteers with two separate sequential procedures, entailing standard venipuncture with hand opened throughout blood collection, or clenching the fist six times before venipuncture and maintaining the fist until completion of blood collection. The parameters tested included red blood cell (RBC) count, hemoglobin, hematocrit, mean corpuscular volume (MCV), RBC distribution width, white blood cell count and differential, including neutrophils, lymphocytes, monocytes, eosinophils, basophils, large unstained cells, platelet count, mean platelet volume, and reticulocytes. The results were reported as median and interquartile range. The comparison of data obtained with the two different venipuncture procedures (i.e., with or without fist clenching and closed hand) was performed with Wilcoxon-Mann-Whitney ranked-pairs test. The degree of statistical significance was set at P<.01., Results and Conclusion: Fist clenching and maintenance during blood collection for routine hematology testing was effective to increase the MCV by 1.2% (P<.001). All others hematological parameters were not significantly biased by fist clenching, though hematocrit, neutrophils, eosinophils, and reticulocytes displayed mindful of trends. We hence advise patients against clenching their fist before blood collection for hematology testing., (© 2016 Wiley Periodicals, Inc.)

Objectives: To investigate the associations, if any, between preoperative plasma levels of total testosterone (TT) and pathology Gleason score (pGS) in a contemporary cohort of prostate cancer (PCa) patients., Materials and Methods: Between November 2014 and June 2015, plasma levels of TT were measured in 142 patients who underwent radical prostatectomy. Exclusion criteria were as follows: 5α-reductase inhibitors, LH-releasing hormone analogues, or testosterone replacement treatment. The entire cohort, assessed by continuous and categorical variables, was classified into two groups according to the pGS that included low-intermediate (pGS 6-7) and high grade (pGS > 7) cases. TT was evaluated as a continuous variable., Results: The cohort included 128 cases. High grade PCa was detected in 28 (21.8%) patients. Median plasma levels of both TT and prostate specific antigen (PSA) were significantly higher in these cases. In the clinical multivariate model, independent and positive predictors of pGS > 7 were TT (p = 0.041; OR = 1.004), PSA (p = 0.006; OR = 1.191), and bGS > 6 (p = 0.004; OR = 5.0); that is, a single unit increase in TT plasma levels increases the odds of having high grade PCa by 4%., Conclusion: In a contemporary cohort of patients, preoperative plasma levels of TT directly and independently associated with high grade PCa. High baseline plasma levels of TT might have clinical applications for managing PCa. New and well designed prospective studies dealing with this subject are required.

Objective: The hemolytic product free-hemoglobin (fHb) reduces nitric oxide (NO) bioavailability. The present study aims to establish whether administration of different blood transfusions result in increased circulating fHb levels and NO consumption with effects on arterial NO-dependent blood flow in patients undergoing CABG surgery., Methods: Ninety-five consecutive patients undergoing elective CABG surgery were prospectively divided in four groups based on blood transfusion requirements during surgery: stored blood cells (SBC, n. 21), intraoperative autologous salvaged blood (ASB, n. 25), SBC and ASB (n.22), no transfusion (control, n. 27). Blood samples were collected before and after intervention to analyse plasma levels of fHb and NO consumption. Endothelium-dependent relaxation was assessed in left internal mammary artery (LIMA) rings harvested before chest closure. Peripheral artery tonometry was assessed after intervention., Results: Transfusions with SBC increased plasma fHb (p<0.05). Transfusions of ASB resulted in higher plasma fHb compared to SBC (p<0.01). fHb concentrations directly correlated with NO consumption (r=0.65, p<0.001). Maximal endothelium-dependent relaxation in LIMA was significantly attenuated in SBC and ASB patients compared to control (15.2±3.1% vs 21.1±2.5% vs 43±5.0% respectively; p<0.01). Significant correlations were identified between the aortic pressure wave velocity, plasma fHb concentration and NO consumption (p<0.01)., Conclusions: Intraoperative blood transfusions and particularly autologous salvaged blood impair endothelium-dependent relaxation through NO scavenging by fHb. These findings obtained in vitro and in vivo provide new insights into the adverse relation between blood transfusions and patient outcome., (Copyright © 2017 Elsevier Inc. All rights reserved.)