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Milano, Italy

Ferraro S.,UOC Patologia Clinica | Ferraro S.,University of Milan | Panteghini M.,University of Milan
Clinical Chemistry and Laboratory Medicine | Year: 2015

The availability of so-called high-sensitivity troponin assays (hsTn) has scored a compelling goal for laboratory medicine, allowing the safe clinical application of international recommendations for the definition of acute myocardial infarction (AMI). However, the introduction of hsTn has not been welcomed by clinicians, claiming an increase in false-positive results. Here we critically trace back the steps following the introduction of hsTn by referring to the 5-year practical experience in our academic hospital and to suitable information available in the literature. In agreement with published data, we found that hsTn introduction was associated with an increased number of AMI diagnoses, whereas the test volume, the revascularization rate, and the proportion of cases with negative angiography findings remained virtually unchanged. Fast-track protocols for ruling out AMI have been further optimized to recommend sampling at presentation and after 3 h only. We focus on a cost-effective use of hsTn that can account for all clinical variables increasing the pre-test probability in order to ensure that tests are ordered only for patients at medium to high risk for acute coronary syndrome (ACS). To guide interpretation of results, hsTn typical release patterns suggestive for AMI should be identified by evaluating the significance of concentration changes. hsTn have markedly shortened the time to rule out or rule in AMI and has the potential to improve the prognostic assessment of critical patients in clinical contexts different from ACS. © 2015 by De Gruyter.

Braga F.,UOC Patologia Clinica | Braga F.,University of Milan | Ferraro S.,University of Milan | Ieva F.,University of Milan | And 2 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2015

Background: Population-based reference intervals have very limited value for the interpretation of laboratory results when analytes display high biological individuality. In these cases, the longitudinal evaluation of individual results using the reference change value (RCV) is the recommended approach. However, the traditional model for RCV calculation requires a Gaussian frequency distribution of data and risks to overestimate the parameter if a correlation between within-subject serial measurements is present. Methods: We propose and validate an alternative non-parametric statistical model for interpretation of differences in serial results from an individual, overcoming data distribution and correlation issues. Results: After describing the traditional and newly proposed statistical models, we compared them with each other using a simulation on three specific analytes displaying different concentration distributions in biological setting. We demonstrated that when analyte concentrations followed a Gaussian frequency distribution, as in the case of glycated hemoglobin, both methods can be used equally. On the contrary, if analyte concentrations present a bimodal (e.g., chromogranin A) or skewed (e.g., C-reactive protein) distribution, the information obtained by two statistical methods is different. Conclusions: The proposed statistical approach may be more appropriate in assessing difference between serial measurements when individual data are not normally distributed. © 2015 by De Gruyter.

Pasqualetti S.,UOC Patologia Clinica | Szoke D.,University of Milan | Panteghini M.,University of Milan
Clinical Chemistry and Laboratory Medicine | Year: 2016

Background: Pneumatic tube transportation (PTT) may induce hemolysis (H) in blood samples. We aimed to compare the H degree before and after PTT implementation in our hospital. Methods: Hemolysis indices (HI) for all lithium-heparin plasma samples (P) drawn by the Emergency Department in 2-month periods were retrospectively collected and pre- (n=3579) and post-PTT (n=3469) results compared. The impact of PTT introduction was investigated on LDH [HI threshold (HIt), 25], conjugated bilirubin (cBIL) (HIt, 30), K (HIt, 100) and ALT (HIt, 125). In addition, HI retrieved for P and paired serum samples collected in silica clot activator tubes (S) from the same venipuncture were compared in pre- (n=501) and post-PTT (n=509) periods. Results: Median (5-95th percentile) HI in P was significantly higher in post-PTT period [7 (0-112) vs. 6 (0-82), p<0.001]. Results reported as 'Hemolysis' in P increased from 6.6% in pre-PTT to 9.4% in post-PTT (p<0.001). Investigated tests gave the following rejection rates (pre-PTT vs. post-PTT): LDH, 13.4% vs. 18.8%, p<0.001; cBIL, 9.4% vs. 27.0%, p<0.05; K, 3.7% vs. 5.6%, p<0.001; ALT, 2.9% vs. 4.4%, p<0.01. The slightly higher susceptibility to H of S compared to paired P found in the pre-PTT [9 (1-64) vs. 6 (0-85)] was not confirmed in the post-PTT period [7 (0-90) vs. 8 (1-72)], in which median HI in S was significantly lower (p<0.001) than in pre-PTT. Conclusions: In our setting PTT promotes H in P, increasing the rate of rejected tests. The use of S appears to protect against the hemolysing effect of PTT. © 2016 by De Gruyter.

Mussap M.,Uoc Medicina Of Laboratorio | Graziani M.S.,Azienda Ospedaliera Universitaria Integrata di Verona | Caldini A.,Laboratorio Generale | Dolci A.,UOC Patologia Clinica | Merlini G.,University of Pavia
Biochimica Clinica | Year: 2014

The contrast media, widely used in imaging diagnostics, show a favorable safety profile. As the presence of pre-existing disease is considered a risk factor for adverse events, patients should be carefully evaluated prior to the procedure. The aim of this consensus document is to recommend appropriate biochemical tests to be performed for an early recognition of individuals at higher risk of contrast media nephrotoxicity. This condition is defined by an increase of serum creatinine concentrations of at least 0.50 mg/dL and/or 25% within 3-4 days from contrast media exposure. The most important risk factor is renal insufficiency [estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2 or serum creatinine >1.50 mg/dL]. Other risk factors are age >75 years, dehydration, diabetes, heart failure and anemia. Monoclonal gammopathies, multiple myeloma, Waldenström macroglobulinemia and amyloidosis are not considered risk factors per se. On the basis of available guidelines, it is recommended: a) prior to the examination, to measure serum creatinine baseline with a method traceable to the international reference measurement system and report its concentration together with the eGFR using the Chronic Kidney Disease - Epidemiology Collaboration (CKD-EPI) equation; b) for monitoring, to measure serum creatinine more than once calculating the delta from the baseline value: if serum creatinine increases >5%, repeat the test within 48- 72 h. Performing of laboratory tests to exclude the presence of monoclonal gammopathies (i.e., serum protein electrophoresis, Bence Jones protein determination, serum free light chain measurements) is not required.

Terzuoli L.,University of Siena | Silvietti A.,UOC Patologia Clinica | Scapellato C.,UOC Patologia Clinica | Porcelli B.,University of Siena | Cappelli R.,University of Siena
Rivista Italiana della Medicina di Laboratorio | Year: 2015

Background: For over a year, even in Italy, are in use the new oral anticoagulants direct: dabigatran, a direct thrombin antagonist, and rivaroxaban, direct inhibitor of factor Xa. The advantage of these new drugs, with the same efficacy and safety compared to anticoagulants vitamin K antagonists, is due to their fixed-dose administration, the fewer drug interactions and no with the food, but most do not require monitoring of laboratory, if we exclude the periodic assessment of renal function. They have a short half-life, beginning and end of action fast. On the other hand, potential drawbacks regarding the use of these drugs are represented by the lack of antidotes in case of overdose or bleeding and the difficulty of controlling patient adherence. From a laboratory point of view the disadvantage is given by the difficulty of monitoring their effect with the current test, because the standard tests are not sufficient to provide an accurate answer, because of their poor or excessive sensitivity. Each Laboratory must therefore be organized in order to determine, in the presence of major bleeding events and/or to perform emergency surgery, the level of anticoagulation patient’s blood. The best way to answer the clinical question will therefore give the value of the drug present in that moment in the patient plasma. The purpose of this work is the development of the dosage of these drugs in the coagulometer available in our laboratory, in order to provide in the future, even in the regime of urgency, a quick response to the clinician. Methods: The methods for the assay of new oral anticoagulants direct were applied on the instrument BCS XP (Siemens Healthcare, Erlangen, Deutschland). The kit used for the quantitative determination of dabigatran is the BC Thrombin (Siemens Healthcare), the reagent used to assess the thrombin time in citrated human plasma. The method was suitably modified to provide a thrombin time defined diluted. The kit used for the quantitative determination of rivaroxaban is Berichrom Heparin (Siemens Healthcare) chromogenic assay specific for factor Xa. It was possible to build the appropriate calibration curves thanks to plasma calibrators and verificate with control plasma supplied by Hyphen BioMed (Neuville-sur-Oise, France). Results: The methods used are reliable and reproducible in a range between 24 and 497 ng/ml. Below 24 ng/ml will not be possible to give an exact value and values greater than 497 ng/ml, if required, will be necessary to dilute the sample. The coefficients of variation percentage intra-day and inter-day are all below 10% and the calibration curves have an r2=0.96$r^{2} = 0.96$. Conclusions: Our study shows that the methods selected and applied on coagulometer BCS XP in use in our laboratory are performed with the automatic procedure, in regime of urgency, in a time of about 30 minutes. The increase in the use of these drugs in clinical practice will help doctors to assess how the amount of the drug in plasma can be linked with the ability of the patient anticoagulant. © 2015, Springer-Verlag Italia.

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