1,720,995 research outputs found
Un ulteriore passo verso una migliore efficienza ed efficacia della determinazione della calprotectina fecale
No full textAppropriateness of tumor marker (TM) ordering after application of local guidelines (LG) : do not loose the control
No full textImprecisione di alcuni metodi di misura dell’albumina derivata dai dati di un Controllo di Qualità Interno
No full textTumor marker odering: do not lose control : a prospective clinical trial
No full textObjectives: In this study, we evaluated the extent of inappropriate tumor marker (TM) ordering in a secondary care setting, approximately 6 years after the introduction of local guidelines, and we identified the main factors potentially influencing clinicians when performing an inappropriate TM request.
Methods: For this purpose, we regularly checked all requests containing more than two TMs. During the 21-month audit, the rate of rejected requests amounted to 3.6%. Several of those were performed for diagnostic purposes. The most frequent and inappropriately requested TMs were carcinoembryonic antigen and carbohydrate antigen 19.9.
Results: The inappropriateness of requests appeared to be linked to the need for more education and knowledge on their clinical applicability and limitations. The clinical motivation was generally associated with patients displaying nonspecific signs/symptoms (ie, weight loss with worsening general conditions), having an incidentally positive result to some recently performed TM tests, or being tested by a TM to avoid more expensive diagnostic imaging procedures.
Conclusions: Our data show that real-time control and management of inappropriate requests by laboratory professionals may be relevant to increase the clinical
efficacy of TM testing and useful in perspective to drive the introduction of new validated biomarkers
Tracing a roadmap for vitamin B12 testing using the health technology assessment approach
No full textAbstract: In our hospital, we are currently working to manage the appropriateness of vitamin B12 (B12) testing. Unfortunately, the classic evidence-based approach is unhelpful
in this process and meta-analyzing data on the accuracy of this marker for cobalamin deficiency detection is mis-
leading due to the lack of reference diagnostic methods.
The approach currently proposed by the Health Technology Assessment (HTA) enables us to tackle the issue of
B12 requests as a “healthcare” problem by considering the position of stakeholders involved in ordering, performing, interpreting the test, and receiving its results. Clinical
expectations, methodological issues, and ethical aspects concerning the performance of the test can aid us in providing more guidance on the use of this marker. By building such structured information, hemodialysis patients and pregnant women have emerged as those groups preferentially requiring B12 testing, as it may potentially improve the clinical outcome. To avoid misinterpretation
of B12 results more care should be taken in considering its biochemical and biological features, as well as the analytical issues. Spurious values obtained by current automated
immunoassays may reflect suboptimal pre-analytical steps as well as known interfering conditions. Furthermore, the harmonization of results by available methods is still a farreaching goal and the approach to interpret an individual’s results should be improved. Tracing a roadmap for B12 testing by exploiting the HTA model to balance the stake-holders’ claims and maximizing the patient’s outcome may help to manage the marker demand
Revaluating serum ferritin as a marker of body iron stores in the traceability era
No full textSerum ferritin is used for diagnosing iron-related disorders.
However, most studies validating this application were performed
before the introduction of the 2nd and 3rd WHO
International Standards (ISs) to harmonize assay results. We
revised the available literature to evaluate if consolidated
clinical applications of ferritin and recommended cut-offs
have been validated using ISs calibrated assays. All Medline
retrieved reviews and individual studies performed since ISs
availability were selected and analyzed according to predefi
ned criteria. Concerning ferritin and iron defi ciency (ID),
only one review, including studies published before 1988, met
established criteria. Results showed that ferritin can effectively
rule out ID anemia in patients with or without infl ammatory
disease at cut-offs of 70 and 40 μ g/L, respectively.
From two studies using ISs calibrated assays that met inclusion
criteria, no information emerged on which cut-off should
be employed to obtain similar sensitivity. Regarding iron
overload, even when the framework was restricted to hereditary
hemochromatosis, no synthesis of scientifi c evidence, if
any, about diagnostic accuracy of ferritin was available both
before and after ISs introduction. Available evidence of the
ferritin diagnostic effectiveness is limited to ID conditions.
Recommended cut-offs for this application are, however,
based on studies published from 1970 to the 1980s using nonharmonized
assays
Cancer biomarkers 2013: appunti a margine del convegno satellite EuroMedLab
No full textCancer biomarkers 2013: notes about the EuroMedLab satellite meeting. Like all other interventions and devices in health care, cancer biomarkers should undergo a careful validation process before they are introduced into clinical
practice for diagnostic or prognostic purposes. Particularly, for those candidate diagnostic markers, validation implies the assessment of their diagnostic accuracy according to pre-specified and standardized criteria. For prognostic purposes, large, protocol-driven prospective studies should assure unbiased results on the effectiveness of the investigated biomarkers in predicting patient’s risk of a future outcome, in aiding individual treatment choice and in patient counselling. The improvement of the methodology of research should finally contribute evidence of high level and strength useful to recommend or not the appropriate application of specific biomarkers in different clinical settings (screening, primary/secondary care, treatment monitoring, follow-up). In this presentation, we summarized the major
issues highlighted during the recent EuroMedLab satellite meeting held in Venice (IT) on May 2013, in which
standardized processes from the evaluation of biomarkers’ diagnostic accuracy and prognostic value for guideline development were discussed. In addition, current efforts on the research of novel molecules and therapeutic targets (proteins, exosomes, circulating nucleic acids) candidate to clinical introduction were briefly reviewed
Recording, monitoring and managing preanalytical issues in a metropolitan university hospital
No full textadverse impacts on patient safety and care. The pre-analytical phase is responsible for ~70% of these errors. In this study we present the experience in assessing the frequency of the most
common pre-analytical issues in our university hospital by monitoring their trend over time and comparing, when possible,data with goals suggested in literature. The impact of corrective
actions, if any, was also checked.
Methods: A comprehensive retrospective analysis of the preanalytical
nonconformities (NC) recorded through laboratory information system over a 5-year (2007-2011) time span was
undertaken. Retrieved data were evaluated on a yearly basis
for NC type and then for type of sample and for involved laboratory section and hospital department.
Results: The relatively most frequent NC was the test request without the corresponding sample, accounting on average for 2.3% of all requested tests. Hemolysis occurred in 1.15%
(mean value over 5 years) of requested tests, affecting ~20,000 determinations per year, mostly interesting clinical wards taking care of critically ill patients, i.e. neonatology, oncology and
emergency department. Clotted and not sufficient samples showed a significant reduction over time, induced by the
change of the analytical system measuring erythrocyte sedimentation rate and the corresponding replacement of sodium citrate rectangular tubes by more reliable K3EDTA round tubes, easier to fill in and mix cup. NC related to samples conveyed at wrong temperature, both for tests requiring
transportation in ice bath (i.e. ammonium) or at 37 °C temperature (i.e. cryoglobulins), were also relative frequent.
Conclusions: Our results show that recording, monitoring and critically evaluating pre-analytical issues in laboratory testing process is mandatory for providing a good laboratory service,
permitting to identify the causes of NC and to apply corrective interventions that may help to reduce their incidence
Prevalence and clinical significance of enormously increased CA 19.9 concentrations in hospitalised patients
No full textBackground: Markedly elevated CA 19.9 concentrations in
serum are regarded as specific enough to reliably identify
pancreatic cancer, even if a consistent body of literature shows
CA 19.9 concentrations >1000 kU/L in a variety of benign
conditions. Scarce data are, however, available on the
prevalence and clinical significance of CA 19.9 values >10,000
kU/L. Here we present a case series of consecutive patients
admitted to our hospital with CA 19.9 concentrations >10,000
kU/L, with the aim to assess the association of such
concentrations with the presence of pancreatic cancer and,
more in general, with tumours of the gastrointestinal system.
We also tried to define whether the exact measurement of CA
19.9 concentrations in this range, which needs serial sample
dilutions, is cost-effective.
Methods: CA 19.9 measurements, including a 1:10 sample
dilution in accordance to manufacturer’s instructions allowing
the determination of concentrations up to 10,000 kU/L, were
performed on Roche Modular EVO system. Samples with
higher CA 19.9 values were diluted according to a defined
laboratory protocol to obtain estimates up to 100,000 kU/L.
Results: During 14 months, 18 patients showing an enormous
elevation of CA 19.9 concentrations (11,568 to >100,000 kU/L)
were identified (55% males; median age 73.5 years, range: 58-
85). Accordingly, the yearly prevalence of hospitalized patients
tested for CA 19.9 and with marker concentrations >10,000
kU/L was 2.9%. All recruited patients were diagnosed as
malignancies: 15 had primary or secondary pancreatic cancer,
two had gastric cancer and one a cholangiocarcinoma. CA 19.9
concentrations ranged between >10,000-30,000 kU/L in 9
cases, >30,000-60,000 kU/L in two, >60,000-100,000 kU/L in
three and >100,000 kU/L in four cases, respectively. A surgical
resection of the tumour was performed in 5 patients,
independently of CA 19.9 concentrations. The median patient’s
survival was <6 months.
Conclusions: CA 19.9 concentrations >10,000 kU/L
unequivocally identify a gastrointestinal malignancy, more
frequently (~83%) a primary or secondary pancreatic cancer.
Exactly measuring CA 19.9 concentrations >10,000 kU/L after
multiple sample dilutions does not add relevant information for
patients’ prognosis and treatment
Biological variation of neuroendocrine tumor markers chromogranin A and neuron-specific enolase
No full textObjectives: Chromogranin A (CgA) and neuron-specific enolase (NSE) are biomarkers for neuroendocrine tumors. Although the knowledge of their biological variation (BV) is critical, only one study for CgA and no data for NSE are available. We report a definitive assessment of BV components of these biomarkers in the same cohort of subjects by an accurately experimental protocol. Design and methods: We collected five blood specimens from each of 22 healthy volunteers (10 men and 12 women, 23–54 years) on the same day every two weeks for two months. Serum specimens were stored at −80 °C until analysis and analyzed in a single run in duplicate. Data were analyzed by ANOVA. Results: Serum CgA concentrations were significantly higher for women than for men (P=0.01), whereas no difference was found for NSE. Intra-individual variance was not different between genders for both biomarkers. Within- and between-subject CVs were 16.3% and 33.5% for CgA and 13.6% and 11.5% for NSE, respectively. CgA showed marked individuality, suggesting that the use of population-based reference limits is inadequate for its interpretation. Conversely, the low individuality of NSE allows the use of a single reference interval. Reference change values were 46% for CgA and 39% for NSE. Desirable analytical goals for imprecision, bias, and total error were b8.2%, ±9.3%, and ±22.8% for CgA, and b6.8%, ±4.5%, and ±15.7% for NSE, respectively. Conclusion: In this study, we defined BV components of serum CgA and NSE and derived indices that may improve the clinical use of these biomarkers
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