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Biochimica Clinica: VOL.41 N.1

Scarica intero fascicolo
Vitamina D: aspetti clinici e di laboratorio
Vitamin D: clinical and laboratory aspects

In addition to the known effects on bone metabolism, vitamin D has a role in many biological processes. Vitamin D is indeed involved in muscle function, cognitive impairment and in the onset of diabetes. The analysis and interpretation of results of clinical trials lead, however, to conclusions often contradictory and difficult to interpret and apply in clinical practice. In recent years, the increased attention to the hypovitaminosis D and its prevention has resulted in an increase in demand of laboratory determination of vitamin D. This has produced an evolution in the laboratory techniques and a demand for automated testing, with the development of analytical systems working in a short time and in complete automation. The establishment of EQAS and the availability of reference materials through which various assays can be evaluated seek to overcome the problem of inter-assay variability, with the aim to standardize the quantification of 25-hydroxyvitamin D and to improve its performance in terms of accuracy.

TAG: vitamina D   25- idrossicolecalciferolo   ipovitaminosi  
Biochimica Clinica 2017; 41(1) 012-022
DOI: 10.19186/BC_2017.001
Pubblicato online il: 09.02.2017
Rassegne - Reviews
 
Marcatori di rimodellamento e fibrosi cardiaca
Markers of cardiac remodeling and fibrosis

Cardiac remodeling is considered the determinant of the clinical progression of heart failure. It is defined as a genome expression resulting in molecular, cellular and interstitial changes, clinically manifested as changes in size, shape and function of the heart. Ventricular remodeling occurs progressively in untreated patients after large myocardial infarction and in those with longstanding cardiomyopathy. Myocyte hypertrophy, cellular apoptosis and increased interstitial collagen deposition are the anatomopathological alterations leading to increased myocardial fibrosis. Myocardial hypertrophy and fibrosis increase left ventricular volume and induce perturbation in the left ventricular chamber geometry, leading to cardiac dysfunction. As a result, the assessment of cardiac fibrosis holds important clinical value in patients with heart failure. Accordingly, there is an increasing interest in the development of new markers for cardiac fibrosis and a number of laboratory tests have been recently proposed. The aim of the present article is to discuss analytical performances and clinical relevance of these markers.

TAG: biomarcatori cardiovascolari   galectina-3   sST2  
Biochimica Clinica 2017; 41(1) 023-038
DOI: 10.19186/BC_2017.002
Pubblicato online il: 09.02.2017
Rassegne - Reviews
 
La sindrome dell’ovaio policistico
Polycystic ovary syndrome
P. Moghetti  |  C. Bonin  | 

Polycystic ovary syndrome (PCOS) is a common and heterogeneous disorder of young women, affecting at least 6-8% of subjects in the reproductive age. Diagnosis is based on the presence of variable combinations of at least two out of 3 clinical elements, i.e. hyperandrogenism (clinical and/or biochemical), chronic oligo-anovulation and polycystic ovarian morphology, after exclusion of secondary causes. PCOS is also frequently characterized by obesity and insulin resistance, with an associated risk of metabolic alterations and cardiovascular disease. The presence of both hyperandrogenism and oligo-anovulation identifies in these women the classic phenotype of this syndrome, which is characterized by a worse metabolic profile. Therefore, the detection of hyperandrogenism is of major clinical significance in PCOS subjects. Unfortunately, the assessment of both clinical and biochemical hyperandrogenism usually relies on inaccurate methods. The treatment of these women should be personalized: lifestyle intervention is always recommended in subjects with fat excess, whereas the choice of medications depends on specific needs and characteristics of each patient.

TAG: anovulazione   iperandrogenismo   insulinoresistenza   sindrome metabolica   obesità  
Biochimica Clinica 2017; 41(1) 039-049
DOI: 10.19186/BC_2017.010
Pubblicato online il: 20.02.2017
Rassegne - Reviews
 
Validazione del dosaggio delle metanefrine plasmatiche mediante cromatografia liquida associata alla spettrometria di massa tandem
Validation of the measurement of plasma metanephrines by liquid chromatography-tandem mass spectrometry (LC-MS/MS)

The prevalence of arterial hypertension is very high all over the world. ~0.1% of subjects with secondary hypertension has a pheochromocytoma, a tumor producing catecholamines. The quantification of free plasma o-methylated metabolites, metanephrine (p-MN) and normetanephrine (p-NMN), is considered the most accurate test for both the diagnosis and monitoring of pheochromocytoma. The aim of this work was to validate of an assay for measuring plasma metanephrines by LC-MS/MS. Calibration curves showed good linearity (R2 >0.99). Intra-assay repeatibility, assessed on two pools, normal and pathological, resulted in a CV of 5.1% and 3.9% for p-MN and 8.2% and 10.5% for p-NMN, respectively. Inter-assay CVs were 15.9% and 11.9% for p-MN and 16.6% and 16.1% for p-NMN, respectively. The limit of detection was 8 pM for p-MN and 66 pM for p-MNM, while the limit of quantification was 26 pM for p-MN and 83 pM for p-NMN. 638 plasma samples were analyzed, providing a representative sample to assess potential clinical impact of the validated method.

Biochimica Clinica 2017; 41(1) 050-059
DOI: 10.19186/BC_2017.007
Pubblicato online il: 17.02.2017
Contributi scientifici - Scientific papers
 
Sviluppo di un metodo in cromatografia liquida associata alla spettrometria di massa tandem per valutare la permeabilità intestinale nella pratica clinica
Development of a liquid chromatography-tandem mass spectometry (LC-MS/MS) method to evaluate intestinal permeability in clinical practice

The intestinal permeability test is a non-invasive method for assessing gastrointestinal mucosal integrity. The lactulose/mannitol ratio is used to assess the intestinal barrier function. Aim of this work was to develop a rapid and robust method for the simultaneous analysis of lactulose and mannitol in urine by LC-MS/MS. Calibration curves were prepared in water:acetonitrile 20:80. Raffinose was used as internal standard at 25 mg/L in water:acetonitrile 20:80. 50 μL of urine sample was added to 450 μL of internal standard solution, and then vortexed and centrifuged. A 200 μL aliquot was transferred into a vial and placed in the autosampler for LCMS/MS analysis. The chromatographic separation was performed using a Phenomenex Luna NH2 column operating at a flow rate of 200 μL/min and eluted with a linear gradient from 20 to 80 water in acetonitrile. The total run time was 16 min. The MS operates in electrospray negative mode. The method was validated according to European Medicine Agency guidelines. Linearity ranged from 10 to 800 mg/L for mannitol and from 2.5 to 400 mg/L for lactulose, respectively. Inter-assay imprecision (expressed as CV) was <13% for both analytes. Recovery was >85%.

TAG: cromatografia liquida   spettrometria di massa tandem   permeabilità intestinale  
Biochimica Clinica 2017; 41(1) 060-063
DOI: 10.19186/BC_2017.011
Pubblicato online il: 21.02.2016
Contributi scientifici - Scientific papers
 
Valutazione dell’esattezza della misura della fosfatasi alcalina sierica in un gruppo di laboratori italiani
Evaluation of the trueness of serum alkaline phosphatase (ALP) measurement in a group of Italian laboratories

The reference measurement procedure for ALP published in 2011 by the IFCC allowed to define the metrological traceability chain for the standardization of ALP measurement. This paper reports the results of an EQA experiment conducted to evaluate the level of ALP standardization among different Italian laboratories enrolled for a scientific project with the final aim to derive ALP traceable reference intervals for pediatric population. Three frozen serum pools with a target value assigned by the IFCC reference procedure were distributed to 13 centers and analyzed in triplicates for 3 different days. Only 3 laboratories averagely fulfilled the desirable goal of bias (≤±5.5%) at all 3 concentrations (59.9 U/L, 186.9 U/L and 401.5 U/L), but only one provided data with a dispersion always within the uncertainty of the target result. The different ability to meet the goal clearly depended on the analytical system used. Focusing on the two most used analytical platforms, the Cobas systems (Roche Diagnostics) underestimated the ALP values, while the AU systems (Beckman Coulter) overestimated them. The regression parameters between the average values obtained by laboratories and the target values indicate that it would be possible to correct the results of all analytical systems and make them unbiased by a simple recalibration approach. The analysis of the commercial calibrator package inserts of the IVD companies involved in this study showed that, with the exception of Roche still aligned to the old Tietz method published in 1983, all companies offer at least two options, sometimes (e.g., Beckman AU) both not in line with the recommended standardization approach.

TAG: fosfatasi alcalina   standardizzazione   valori di riferimento  
Biochimica Clinica 2017; 41(1) 064-071
DOI: 10.19186/BC_2017.005
Pubblicato online il: 15.02.2017
Contributi scientifici - Scientific papers
 
Correlazione tra dati istologici e profili immunofenotipici in pazienti affetti da mieloma multiplo in differente tipo di trattamento
Correlation between bone marrow histology and plasma cell immunophenotyping in patients with multiple myeloma under various treatments

The diagnostic and response criteria of multiple myeloma have been established by the International Myeloma Working Group. Although bone marrow morphology represents the gold standard both in the diagnostic and in the post-therapy practice, the role of multiparameter immunophenotyping by flow cytometry is currently gaining importance. The rapidity and high sensitivity to distinguish normal plasma cells from the pathological ones make this technique a precious tool, especially in defining the therapeutical response and in detecting minimal residual disease. We compared 92 simultaneous patterns of plasma cell immunophenotype and bone marrow morphology of multiple myeloma, after treatment with either chemoterapy alone or high-dose therapy with autologous or allogeneic stem cell transplantation. The aim was to determine the percentage of agreement of the two techniques in establishing the response to treatment. Discordant results were obtained in 6 cases, in which flow cytometry was able to correctly establish the degree of response to therapy. Our study shows the utility of using flow cytometry in response assessment in patients treated for multiple myeloma, with particular reference to patients in apparent complete remission and patients with oligoclonal bands observed after high-dose therapy.

Biochimica Clinica 2017; 41(1) 072-078
DOI: 10.19186/BC_2017.009
Pubblicato online il: 20.02.2017
Contributi scientifici - Scientific papers
 
Verifica dell’accuratezza di tre glucometri “point-of-care” per l’utilizzo in ambito ospedaliero
Verification of accuracy of 3 glucose point-of-care testing (POCT) devices for their use in a hospital setting

Inaccuracy in glucose POCT can lead to inappropriate therapeutic decisions. In this study, we evaluated the performance of 3 POCT glucometers by comparing results to those by an automated system traceable to higher-order references. Thirty-one heparinized venous blood samples were collected and assayed in duplicate for whole blood glucose concentrations with Roche Accu-Check Compact Plus, Nova Biomedical NovaPro and OK Biotech OKmeterDirect glucometers. All systems were calibrated to report plasma-equivalent results. Samples were then centrifuged and plasma glucose immediately determined by the hexokinase assay on Abbott Architect c16000 platform. The traceability of Abbott assay was checked by comparison with the hexokinase reference procedure performed on 3 samples. POCT performance was evaluated according to Cinical and Laboratory Standards Institute (CLSI) POCT12-A3 criteria [max. 5% of results >±12 mg/dL (for reference results <100 mg/dL) or >±12.5% (for reference results ≥100 mg/dL)] and consensus error grid (CEG) analysis. The Architect assay was perfectly standardized (mean bias, 0.2%). Sample glucose concentrations ranged from 62 to 326 mg/dL, with hematocrit spanning from 0.27 to 0.58 L/L. Average CV on duplicates was 3.5% for Roche, 3.6% for Nova and 5.9% for OK Biotech. All meters gave more than 5% of results (Roche 19.4%, Nova 16.1% and OK Biotech 22.6%) outside the CLSI criteria. However, all results, except two borderline values for OK Biotech, were within the low-risk zone according to CEG. In conclusion, by using CLSI acceptability criteria, the evaluated glucometers were not accurate enough for clinical use in a hospital setting. CEG analysis suggests, however, that this inaccuracy would not have any significant impact on patients’ outcome.

TAG: glucosio ematico   standard di riferimento   biotecnologia  
Biochimica Clinica 2017; 41(1) 079-084
DOI: 10.19186/BC_2017.006
Pubblicato online il: 15.02.2017
Contributi scientifici - Scientific papers
 
Linee guida per la valutazione del rischio cardiovascolare: siamo a rischio di confusione?
Guidelines for cardiovascular risk assessment: do we risk an overcrowding?

Cardiovascular diseases are highly prevalent in Western countries. Among modifiable risk factors for cardiovascular events, dyslipidaemias have a predominant role, being conveniently controlled either by a healthy lifestyle or by drugs, when necessary. A number of guidelines have been issued to guide both clinicians and laboratorians to assess the cardiovascular risk and to provide the best patient management. Guidelines accumulated and evolved with time, incorporating new available evidence; however, differences among them could generate disorientation among health professionals. The recent recommendations by the American College of Cardiologists and the American Heart Association are a breaking point in the guideline history, mainly because of the suggestion of abandoning the therapeutic LDL cholesterol targets. In this paper, we illustrate available guidelines, emphasizing the different approaches to risk prediction. The possible adoption of the recent American guideline will pose problems to both clinicians and clinical laboratories. The number of subjects to be treated would markedly increase and the lack of therapeutic targets could hamper the possibility to share with patients the targets to fulfil, jeopardising their compliance. For laboratories, the major issue would be the difficulty to report lipid results according to targets adjusted to risk levels. In an opposite direction, a recent national consensus document suggests adopting in reporting lipid results the desirable lipid levels as established by European recommendations.

Biochimica Clinica 2017; 41(1) 085-095
DOI: 10.19186/BC_2017.008
Pubblicato online il: 17.02.2017
Opinioni - Opinions
 
Attività di SIBioC - Medicina di Laboratorio e soddisfazione dei soci: risultati di un questionario
Survey on the satisfaction of SIBioC members on the society’s activities
S. Buoro  |  M. Ciaccio  |  F. Ceriotti  | 

This report presents the results of a survey performed on Oct-Nov 2015 on SIBioC member satisfaction. The survey addressed event attendance/received value, networking opportunities and overall benefit of SIBioC membership. An on-line questionnaire was sent to all SIBioC members through the web-based SurveyMonkey platform and the resulting database was statistically analyzed. The respondents (514 out of 2000 members) can be considered a representative sample of the associates, since different professional branches were represented proportionally. The large majority of respondents were familiar with SIBioC Newsletter and expressed a positive opinion on it. 71% of the respondents declared to access the official website from 1 to 5 times per month. Finally, 50,8% of respondents declared that they were aware of the existence of Lab Tests Online (LTO) website, with the majority of them (78.2%) being satisfied with it. Overall, the survey data showed a good level of satisfaction with SIBioC educational offer. The only aspect not completely positive was the limited knowledge of LTO, despite the large investment made on it by the society. Regarding the current scenario of reorganization of the laboratory network, many respondents addressed specific requests related to both enhancing the ad hoc education and improving the dialogue with institutions and other scientific societies. In these two fields, SIBioC is currently putting large efforts. Overall, the survey gave a positive feed-back stimulating the SIBioC management to further ameliorate the service to members, with the aim of contributing in continuously improving the quality of laboratory services and then the patient care.

Biochimica Clinica 2017; 41(1) 096-101
DOI: 10.19186/BC_2017.013
Pubblicato online il: 24.02.2017
Documenti - Documents
 
Validazione di nuovi marcatori di neoplasia: la posizione ufficiale dell’“European Group on Tumor Markers”
Validation of new cancer biomarkers: a position statement from the European Group on Tumor Markers

Biomarkers are playing increasingly important roles in the detection and management of patients with cancer. Despite an enormous number of publications on cancer biomarkers, few of these biomarkers are in widespread clinical use. In this review, we discuss the key steps in advancing a newly discovered cancer candidate biomarker from pilot studies to clinical application. Four main steps are necessary for a biomarker to reach the clinic: analytical validation of the biomarker assay, clinical validation of the biomarker test, demonstration of clinical value from performance of the biomarker test, and regulatory approval. In addition to these 4 steps, all biomarker studies should be reported in a detailed and transparent manner, using previously published checklists and guidelines. Finally, all biomarker studies relating to demonstration of clinical value should be registered before initiation of the study. Application of the methodology outlined above should result in a more efficient and effective approach to the development of cancer biomarkers as well as the reporting of cancer biomarker studies. With rigorous application, all stakeholders, and especially patients, would be expected to benefit.

TAG: biomarcatori   studi pilota   riproducibilità dei risultati   gestione dei campioni  
Biochimica Clinica 2017; 41(1) 102-113
DOI: 10.19186/BC_2017.12
Pubblicato online il: 24.02.2016
Il meglio di Clinical Chemistry - Clinical Chemistry Highlights
 
Gestire il rischio clinico in medicina di laboratorio: un’inaspettata piastrinopenia
Clinical risk management in laboratory medicine: an unexpected thrombocytopenia

It is acknowledged that the risk management strategy is cardinal to maintain safety in health care organisations. Clinical risk assessment and management is a continuous and dynamic process aimed to evaluate risks and to develop appropriate plans to reduce them. Internationally, there is an increasing recognition of the need to collect and analyse data on patient safety incidents to facilitate cultural growth and to develop appropriate solutions. The practice of reporting is commonly used, and several countries have established national reporting systems to facilitate large scale monitoring and analysis of data. This activity provides information on the extent, types and causes of errors, adverse events and near misses, supporting healthcare workers in the activity of reporting errors. This case shows how a non-optimal communication between laboratory and clinicians has caused an adverse advent and which corrective actions have been undertaken.

Biochimica Clinica 2017; 41(1) e1-e3
DOI: 0.19186/BC_2017.003
Pubblicato online il: 09.02.2017
Casi Clinici - Case Report
 
Presenza concomitante di anticorpi tipo Lupus e malattia di von Willebrand: una condizione reale?
Combined von Willebrand factor and lupus anticoagulant abnormalities: a true finding?

We present a case of a 74-year-old woman with myelofibrosis, hypothyroidism and negative bleeding history, showing a prolonged APTT performed within a pre-intervention screening. The laboratory tests showed a positivity for the presence of lupus anticoagulant antibodies (LA). Further investigations revealed normal intrinsic factor and von Willebrand factor (VWF) antigen concentrations, and normal to only slightly reduced VWF Ristocetin Cofactor (VWF:RCo) by chemiluminescent assay and by platelet agglutination. The VWF:RCo by a latex- immunoturbidimetric method was strongly reduced and the platelet function test was found to be abnormal. The negative bleeding history, the myeloproliferative chronic disease, the LA positivity and the other laboratory findings were consistent with the presence of acquired VWF disease. However, the disproportionate values of VWF:RCo measurements obtained by the latex method and all the other assays, made us to conclude for the presence of an interference (possibly due to autoantibodies) on latex VWF:RCo immunoassay and the patient went successfully to surgery without anti-haemorrhagic prophylaxis.

TAG: Malattia di Willebrand acquisita   cofattore ristocetinico   diagnosi di laboratorio  
Biochimica Clinica 2017; 41(1) e4-e8
DOI: 10.19186/BC_2017.004
Pubblicato online il: 09.02.2017
Casi Clinici - Case Report
 
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