The standardization of pre-analytical processes is an essential aspect, the management and control of pre-analytical variables are particularly relevant to ensure the reliability of diagnostic tests. Major challenges in this area include the evaluation of hemolysis, which can compromise the accuracy of coagulation tests. ACL TOP 750 CTS (Instrumentation Laboratory, Bedford, CA, USA) instrumentation, equipped with HIL parameters (hemolysis, jaundice, lipemia), allows automated sample quality analysis. The aim of our study was to evaluate the manufacturer’s proposed limits for the hemolysis parameter in the determination of major coagulation tests. In our study, 30 samples collected in tubes containing 3.2% sodium citrate sent to the laboratory for routine coagulation testing were selected. An initial analysis (baseline) was performed and the following parameters were evaluated: prothrombin time (PT), the activated partial thromboplastin time (APTT), fibrinogen (FBG) (Clauss method), D-dimer (DD) and antithrombin (AT). Hemolysis, jaundice and lipemia (HIL) indices were also performed for each sample on the ACL TOP instrumentation. However, the HIL index of the samples was also analyzed on the Cobas 8000 instrumentation (Roche Diagnostics, Rotkreuz, Switzerland). Then, using 100U insulin syringes (1 ml) with G25X 5/8” (0.5x16 mm) needle (Jiangsu Jichun Medical Device Co Ltd, Changzhou, China), the samples were mechanically hemolyzed and all tests were repeated. The hemolysis process was repeated four times, during each of which an amount equal to 20U of the cellular/corpuscular part of the blood was drawn by insulin syringe for four repetitions. Values of PT, APTT, fibrinogen, DD and AT and indices of hemolysis, lipemia and jaundice at baseline state and in the relevant subsequent four cycles of hemolysis were performed and downloaded from the ACL TOP instrument. The HIL indices of the samples on the Cobas 8000 instrument were also performed and recorded for each cycle. To assess significant differences, the initial test result of each analyte (in the baseline state) was compared with the results of the hemolyzed samples at various levels, considering the critical difference (reference change value, RCV) calculated by Fokkema's method; there are several formulas for estimating the RCV, but the most accurate is obtained using the so-called asymmetric RCV formula. The tool available on the EFLM website 'BiologicalVariation.eu' was used for the calculation; the analytical CV% with the lowest value was selected, based on internal quality control data for the 30-day period, in order to obtain the lowest possible RCV. The results showed that the average RCV values for the five analytes over the four cycles of hemolysis were within acceptable limits, confirming that hemolysis, at the levels evaluated, did not significantly alter the results of the coagulation tests. At the fourth cycle of hemolysis, 96% of the samples still provided valid results. Furthermore, comparison of hemolysis indices measured on ACL TOP 750 CTS and Cobas 8000 showed a strong correlation (r²=0.978), confirming the consistency of measurements between the two instruments. The data from our study confirm that the manufacturer's suggested hemolysis limits for ACL TOP are appropriate and allow correct clinical interpretation of coagulation tests. The implementation of automated systems for hemolysis detection and the adoption of standardized protocols are key strategies to ensure the reliability of coagulation tests. Our study showed that the average RCV values for PT, APTT, fibrinogen, DD and AT were not significantly altered confirming the manufacturer's proposed limits. The strong correlation between the instruments used reinforces the validity of the analysis of hemolysis in laboratory sample. These evidences underline the importance of automated management of pre-analytical in favour of more precise and accurate.
La standardizzazione dei processi preanalitici rappresenta un aspetto essenziale e nell'ambito della coagulazione la gestione e il controllo delle variabili preanalitiche risultano rilevanti per garantire l’affidabilità dei test diagnostici. Tra le principali sfide di quest’ambito rientra la valutazione dell'emolisi, che può compromettere l'accuratezza dei test coagulativi. La strumentazione ACL TOP 750 CTS(Instrumentation Laboratory, Bedford, CA, USA), dotata di parametri HIL (emolisi, ittero, lipemia), permette un’analisi automatizzata della qualità del campione. L'obiettivo del nostro studio è stato quello di valutare i limiti proposti dal produttore per il parametro dell’emolisi nella determinazione dei principali test coagulativi. Nel nostro studio sono stati selezionati 30 campioni raccolti in provette contenenti 3.2% sodio citrato inviati al laboratorio per test di coagulazione di routine. È stata effettuata una prima analisi iniziale(baseline) e sono stati valutati i seguenti parametri: il tempo di protrombina (PT), il tempo di tromboplastina parzialmente attivato (APTT), il fibrinogeno (FBG) (metodo di Clauss), il D-dimero (DD) e l'antitrombina (AT). Sono stati inoltre eseguiti gli indici di emolisi, ittero e lipemia (HIL) per ciascun campione sulla strumentazione ACL TOP. L’indice HIL dei campioni è stato tuttavia anche analizzato sulla strumentazione Cobas 8000 (Roche Diagnostics, Rotkreuz, Svizzera). Successivamente, utilizzando siringhe per insulina 100U (1 ml) con ago G25X 5/8" (0,5x16 mm) (Jiangsu Jichun Medical Device Co Ltd, Changzhou, Cina), i campioni sono stati emolizzati meccanicamente e sono stati ripetuti tutti i test. Il processo di emolisi è stato ripetuto quattro volte, durante ciascuno dei quali sono state prelevate, tramite siringa da insulina, una quantità pari a 20U della parte cellulare/corpuscolata del sangue per quattro ripetizioni. Sono stati eseguiti e scaricati dallo strumento ACL TOP i valori di PT, APTT, fibrinogeno, DD e AT e gli indici di emolisi, lipemia e ittero allo stato baseline e nei relativi successivi quattro cicli di emolisi. Sono stati inoltre anche effettuati e registrati per ogni ciclo gli indici HIL dei campioni sullo strumento Cobas 8000. Per valutare differenze significative, il risultato iniziale dei test di ciascun analita (allo stato baseline) è stato confrontato con i risultati dei campioni emolizzati a vari livelli, considerando la differenza critica (reference change value, RCV) calcolata con il metodo di Fokkema; la formula più accurata viene ottenuta utilizzando la cosiddetta formula asimmetrica dell’RCV. Per il calcolo è stato utilizzato lo strumento disponibile sul sito EFLM website 'BiologicalVariation.eu'; è stato selezionato il CV% analitico con il valore più basso, basandoci sui dati di controllo di qualità interno relativi al periodo di 30 giorni, al fine di ottenere il RCV più basso possibile. I risultati hanno dimostrato che i valori medi degli RCV per i cinque analiti nei quattro cicli di emolisi rientravano nei limiti accettabili, confermando che l’emolisi, nei livelli valutati, non alterava significativamente i risultati dei test coagulativi. Al quarto ciclo di emolisi il 96% dei campioni forniva ancora risultati validi. Inoltre, il confronto tra gli indici di emolisi misurati su ACL TOP e Cobas 8000 ha evidenziato una forte correlazione (r²=0.978), confermando la coerenza delle misurazioni tra i due strumenti. I dati del nostro studio confermano che i limiti di emolisi suggeriti dal produttore per ACL TOP sono adeguati e consentono una corretta interpretazione clinica dei test coagulativi. Inoltre, la forte correlazione tra gli strumenti utilizzati rafforza la validità dell'analisi dell’emolisi nei campioni di laboratorio. Tali evidenze sottolineano l’importanza della gestione automatizzata delle interferenze preanalitiche, a favore di una di una diagnostica più precisa e accurata.
Affidabilità della valutazione automatica dell'emolisi nei campioni per test emostatici
GIULIANELLI, GIULIA
2022/2023
Abstract
The standardization of pre-analytical processes is an essential aspect, the management and control of pre-analytical variables are particularly relevant to ensure the reliability of diagnostic tests. Major challenges in this area include the evaluation of hemolysis, which can compromise the accuracy of coagulation tests. ACL TOP 750 CTS (Instrumentation Laboratory, Bedford, CA, USA) instrumentation, equipped with HIL parameters (hemolysis, jaundice, lipemia), allows automated sample quality analysis. The aim of our study was to evaluate the manufacturer’s proposed limits for the hemolysis parameter in the determination of major coagulation tests. In our study, 30 samples collected in tubes containing 3.2% sodium citrate sent to the laboratory for routine coagulation testing were selected. An initial analysis (baseline) was performed and the following parameters were evaluated: prothrombin time (PT), the activated partial thromboplastin time (APTT), fibrinogen (FBG) (Clauss method), D-dimer (DD) and antithrombin (AT). Hemolysis, jaundice and lipemia (HIL) indices were also performed for each sample on the ACL TOP instrumentation. However, the HIL index of the samples was also analyzed on the Cobas 8000 instrumentation (Roche Diagnostics, Rotkreuz, Switzerland). Then, using 100U insulin syringes (1 ml) with G25X 5/8” (0.5x16 mm) needle (Jiangsu Jichun Medical Device Co Ltd, Changzhou, China), the samples were mechanically hemolyzed and all tests were repeated. The hemolysis process was repeated four times, during each of which an amount equal to 20U of the cellular/corpuscular part of the blood was drawn by insulin syringe for four repetitions. Values of PT, APTT, fibrinogen, DD and AT and indices of hemolysis, lipemia and jaundice at baseline state and in the relevant subsequent four cycles of hemolysis were performed and downloaded from the ACL TOP instrument. The HIL indices of the samples on the Cobas 8000 instrument were also performed and recorded for each cycle. To assess significant differences, the initial test result of each analyte (in the baseline state) was compared with the results of the hemolyzed samples at various levels, considering the critical difference (reference change value, RCV) calculated by Fokkema's method; there are several formulas for estimating the RCV, but the most accurate is obtained using the so-called asymmetric RCV formula. The tool available on the EFLM website 'BiologicalVariation.eu' was used for the calculation; the analytical CV% with the lowest value was selected, based on internal quality control data for the 30-day period, in order to obtain the lowest possible RCV. The results showed that the average RCV values for the five analytes over the four cycles of hemolysis were within acceptable limits, confirming that hemolysis, at the levels evaluated, did not significantly alter the results of the coagulation tests. At the fourth cycle of hemolysis, 96% of the samples still provided valid results. Furthermore, comparison of hemolysis indices measured on ACL TOP 750 CTS and Cobas 8000 showed a strong correlation (r²=0.978), confirming the consistency of measurements between the two instruments. The data from our study confirm that the manufacturer's suggested hemolysis limits for ACL TOP are appropriate and allow correct clinical interpretation of coagulation tests. The implementation of automated systems for hemolysis detection and the adoption of standardized protocols are key strategies to ensure the reliability of coagulation tests. Our study showed that the average RCV values for PT, APTT, fibrinogen, DD and AT were not significantly altered confirming the manufacturer's proposed limits. The strong correlation between the instruments used reinforces the validity of the analysis of hemolysis in laboratory sample. These evidences underline the importance of automated management of pre-analytical in favour of more precise and accurate.| File | Dimensione | Formato | |
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https://hdl.handle.net/20.500.12608/82011