1,720,986 research outputs found
Comparative study of fecal calprotectin (FC) rapid test with the established ELISA method
No full textBackground. FC is a useful marker for diagnosing inflammatory bowel disease (IBD). However, no automated assay is available
yet and widely adopted ELISA methods show turnaround time of≥4h. We compared the point of care (POC) Quantum Blue FCimmunochromatographic
test (Buhlmann) to the Calprest ELISA (Eurospital) routinely used in our laboratory.
Methods. Stool specimens of 67 consecutive patients were analyzed after extraction using recommended device. FC was determined
on fresh samples by POC, while for the ELISA stool samples were frozen at -20 °C, and thawed, extracted, and assayed
within 2 weeks from collection. We first compared results by Passing Bablok regression and then estimated diagnostic agreement
by adopting 90 μg/g feces as cut-off for ELISAand an experimentally recalculated cut-off for POC.
Results. Method comparison, performed on 28 paired results higher than the POCdetection limit(30 μg/g), showed a slope of 2.24
(ELISA in x-axis), with not significant intercept. On the basis of this finding, the POC cut-off was established at 200μg/g. FC was
positive on 20 samples by ELISA and on 17 samples by POC, with a 92.5% agreement. Among fivepatients showing discrepant
results, 4 were positive on ELISA (two borderline – 94 and 98 μg/g – results) and one positive on POC. This POC “false-positive”
related to a 16-years old girl, with chronic diarrhea but no IBD diagnosis.
Conclusions. Our preliminary results suggest that POC may replace the standard ELISA and make FC testing more rapid (<20
min), effective, and suitable for any laboratory setting
Valutazione dell’efficacia di raccomandazioni aziendali sulle strategie per l’impiego ottimale dei biomarcatori in oncologia ad un anno dalla loro introduzione
No full textOne-year audit of the implementation of recommendations for optimal use of tumor biomarkers in a university hospital. Tumor biomarkers are increasingly used to make clinical decisions in oncology. It is therefore mandatory to provide evidence-based information both about the optimal use as well as the limitations of these tests to
improve appropriateness of their measurement. For this reason we prepared local recommendations for correct tumor
biomarker use. According to the oncologists and in agreement with the available international guidelines, we identified
the recommended biomarker(s) for any specific clinical goal of different malignancies. As a general rule, we
established a maximum of two biomarker requests in the same order except for well documented clinical situations. To evaluate the impact of recommendations, we compared the same one-year period before and after guideline implementation. The total number of tumor biomarker requests decreased from 14,681 to 6,577 (-55.2%), with some
differences among clinical departments and available biomarkers. Alpha-fetoprotein showed the highest decrease (-67.9%), followed by neuron-specific enolase (-65.5%) and CA125 (-65%). In terms of reagent costs, the laboratory saved € 38,229 per year. During the evaluated period, 349 orders asking for more than two biomarkers were discussed with the clinicians and all but three were brought back to the recommendations. In conclusion, implementing
recommendations on correct use of tumor biomarkers in a teaching hospital largely decrease the number of ordered tests and reagent costs, without any impact on their clinical role
La determinazione dei biomarcatori di neoplasia su analizzatore Roche Modular consente di rispettare ampiamente gli obiettivi desiderabili di imprecisione
No full textAppropriatezza delle richieste di PSA libero in un servizio di Medicina di Laboratorio ospedaliero
No full textLa determinazione della frazione libera dell’antigene prostatico specifico (fPSA) è specificamente indicata nella diagnosi differenziale tra iperplasia prostatica benigna ed adenocarcinoma prostatico, qualora la concentrazione di PSA totale (tPSA) sia compresa nell’intervallo tra 4 e
10 μg/L e l’esplorazione rettale risulti negativa (1). Per valutare l’appropriatezza delle richieste di fPSA, abbiamo quindi verificato retrospettivamente la concentrazione di tPSA dei campioni pervenuti al nostro laboratorio per il
dosaggio di fPSA in due periodi di tre mesi ciascuno, nel primo e nel secondo semestre 2005. Su un totale di 5773 richieste di tPSA, 2247 (38.9%) erano associate a fPSA,
ma di queste solo 352 (15.7%) erano da considerarsi appropriate, mentre 1839 (81.8%) e 53 (2.5%), associate a concentrazioni di tPSA rispettivamente 10 μg/L, risultavano inappropriate. Il costo totale dei dosaggi non giustificati ammontava a C 8135 su base annua.
Analizzando la provenienza delle richieste, si rilevava che, su un totale di 902 determinazioni di tPSA in pazienti ricoverati, nel 9.7% dei casi era richiesto anche il fPSA, ma solo in un quarto di questi in maniera appropriata. Nelle richieste di provenienza ambulatoriale, per un totale di 4871 tPSA, ben 2160 (44.3%) associavano fPSA. Tuttavia, solo una quota significativamente minore (n=330), pari al 15%, era richiesta per valori di tPSA
compresi tra 4-10 μg/L; 1830 determinazioni di fPSA, pari ad un esborso annuo da parte del SSN (tariffa C 13.63 per test) di circa C 50.000, erano da ritenersi inutili.
Dall’analisi dei nostri dati emerge quindi la necessità di interventi mirati al miglioramento dell’appropriatezza delle
richieste di fPSA, soprattutto nei pazienti ambulatoriali nei quali, per un bacino di utenza come quello di un ospedale
metropolitano di media grandezza, il numero di esami inappropriati è pari a circa 300 al mese. Un intervento di “autoprescrizione” del fPSA da parte del laboratorio, con un approccio tipo “reflex testing” in seguito alla determinazione del tPSA, potrebbe dimostrarsi efficace nel ridurre gli sprechi.
(1) Lilja H et al. National Academy of Clinical Biochemistry Guidelines for the Use of Tumor Markers in Prostate Cancer. www.nacb.org, 2006
Imprecision of tumour biomarker measurements on Roche Modular E170 platform fulfills desirable goals derived from biological variation
No full textBackground: Monitoring of test imprecision is one of the most important quality indicators in clinical laboratories. Imprecision goals should be derived from biological variation. The aim of this study was to evaluate the imprecision of eight tumour biomarker assays routinely measured on the Modular E170 system. Methods: Method coefficient of variations (CVs) were obtained by an appropriate Internal Quality Control programme based on the measurement every working day of a fresh-frozen human serum pool with biomarkers concentrations around the clinical cut-offs. We evaluated data collected along the whole year 2008 (n range: 21-461); monthly CVs and their cumulative means were calculated and compared with corresponding goals. Results: Biomarkers concentration means and average yearly CVs (desirable goals in parentheses) were as follows: α-fetoprotein, 9.6 μg/L, 3.9% (6.0%); CA125, 41.2 U/L, 2.8% (12.4%); CA15.3, 32.7 U/L, 3.1% (3.1%); CA19.9, 35.1 U/L, 2.8% (8.0%); CEA, 7.7 μg/L, 4.3% (6.4%); prostate-specific antigen (PSA), 4.1 μg/L, 4.3% (9.1%); CYFRA 21.1, 2.4 μg/L, 5.7% (11.3%); and ferritin, 64.5 μg/L, 4.0% (7.1%). Conclusions: Our study shows that in routine laboratory practice and over a clinically and analytically relevant time-span, the imprecision of the tumour biomarker measurements on the Roche Modular E170 fulfills desirable goals. For four assays (CA125, CA19.9, PSA and CYFRA 21.1) the optimum CV can even be achieved
Automated amidolytic method for activated partial thromboplastin time compared with a conventional coagulation method
No full textWe report studies of the validity and clinical application of a new amidolytic method for evaluating the activated partial thromboplastin time (APTT) compared with a conventional clotting method. The results with the two methods were well correlated for normal plasma and plasma from hemophilia patients. Congenital deficiencies of of the intrinsic coagulation pathway other than hypo- and dysfibrinogenemia detected by the amidolytic method agreed with those detected by the clotting APTT. The results with the two methods for plasma from patients under heparin treatment were statistically different, suggesting a lesser sensitivity of the amidolytic method to heparinization. The use of the amidolytic APTT reagent in combination with factor VIII and IX deficient plasma allowed the measurement of both factors. The results obtained with normal and hemophilic plasma were in agreement with those obtained with the one-stage clotting method in all except two occasions. Even though the amidolytic method demonstrated the presence of the lupus anticoagulant in the majority of tested samples of known lupus subjects, it was less sensitive to the abnormality than the clotting method
Calprotectina fecale : un nuovo indicatore di malattia infiammatoria intestinale
No full textCalprotectin is a S-100 family calcium- and zinc-binding protein. It derives predominantly from neutrophils and monocytes and it is detectable in body fluids and tissue samples. Fecal calprotectin is a marker of intestinal inflammation and it seems to be useful, in gastroenterological practice, for diagnosing and monitoring organic inflammatory bowel disorders (ulcerative colitis and Crohn’s disease) in adults and children. The aim of this review is to discuss biochemical, analytical and clinical findings of this promising marker of intestinal inflammation
Strategie per l'impiego ottimale dei biomarcatori in oncologia: raccomandazioni e protocolli operativi
No full textUtilizzo di un pool di sangue umano fresco congelato per la valutazione intralaboratorio dell’imprecisione della determinazione dell’emoglobina glicata
Full text linkGlycated hemoglobin (HbA 1c) has a key role for the assessment of glycemic state in diabetic subjects. To guarantee the clinical reliability of HbA 1c methods regular IQC programs are mandatory. These programs may give immediate information on the reliability of the analytical system used in the laboratory, providing that employed materials are stable and commutable. In this study we investigated two different preparations to be used as IQC material for HbA 1c, i.e. a classical lyophilized material (CQI1) and a freshly collected whole blood pool stored at -20 °C (CQI2). We also checked the stability of CQI2 at -20 °C compared to -80 °C storage. HbA 1c was determined by an immunoturbidimetric assay on Roche Cobas Integra. The mean (±SD) HbA 1c concentrations in the two materials were 9.1%±0.05 in CQI1 and 6.9%±0.05 in CQI2, respectively. In a following period of 20 weeks the HbA 1c recovery was between 94.6% and 105.7% for CQI1 and between 94.4% and 109.4% for CQI2. Most of CQI1 fluctuations were paired to similar fluctuations of CQI2, proving that these changes were independent of the material properties. When compared with results obtained at -80 °C storage, the HbA 1c concentrations in the CQI2 at -20 °C were stable over the whole study period. In conclusion, our findings demonstrate that fresh-frozen pooled whole blood stored at -20 °C is a suitable and cheap material for use in the IQC programmes for HbA 1c
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