Ispitivanje analitičkih značajki biljega BNP-a, CK-MB i mioglobina

master's thesis

• Title (english): Investigation of the analytical properties of markers BNP, CK-MB and myoglobin
• Author: Anita Topić
• Mentor: Ana-Maria Šimundić (mentor)
• Committee member: Ana-Maria Šimundić
• Committee member: Anita Somborac Bačura
• Committee member: Sandra Šupraha Goreta
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of medical biochemistry and haematology); Zagreb
• Defense date and country: 2015-07-08, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Medical Biochemistry

Abstract

Određivanje koncentracije B-natriuretskog peptida (BNP), kreatin kinaze MB (CK-MB) i mioglobina klinički je najznačajnije u dijagnostici srčanih disfunkcija, kao što je srčano zatajenje i infarkt miokarda. Cilj ovog istraživanja bio je ispitati načine uzrokovanja hemolize u uzorcima seruma te provesti analitičku verifikaciju imunokemijskog testa za određivanje koncentracije BNP-a, CK-MB i mioglobina. Analitička verifikacija obuhvaćala je ispitivanje nepreciznosti metode, utjecaja interferencije lipemije na sva tri analita te interferencije hemolize na određivanje koncentracije CK-MB. Za ispitivanje su korišteni ostatni uzorci seruma ili plazme bolničkih bolesnika zaprimljenih u laboratoriju Kliničkog zavoda za kemiju KBC „Sestre milosrdnice“ u Zagrebu. Hemoliza je ispitivana primjenom hemolizata i smrzavanjem uzoraka, dok je za simulaciju lipemičnih uzoraka korištena komercijalno dostupna otopina Intralipida®. Mjerenja su provedena na imunokemijskom analizatoru Architect i2000 tvrtke Abbott. Rezultati analitičke verifikacije pokazali su da je nepreciznost metode u skladu s navodima proizvođača. Hemoliza i lipemija nisu dovele do značajne promjene u rezultatu mjerenja koncentracije CK-MB. Na određivanje BNP-a, lipemija pri nižim koncentracijama interferenta dovodi do lažno povišenih, a pri višim koncentracijama do laţno sniženih vrijednosti analita. Učinak lipemije na određivanje mioglobina ovisan je o koncentraciji samoga analita u uzorku. U uzorcima seruma hemolizu nije bilo moguće izazvati miješanjem uzoraka na vortexu niti protjerivanjem uzorka kroz iglu. Značajna hemoliza dobivena je smrzavanjem i miješanjem uzoraka s homogenizatorom. Zaključno, metoda je zadovoljavajuće nepreciznosti, hemoliza i lipemija ne utječu na određivanje koncentracije CK-MB, lipemija dovodi do značajnih promjena u rezultatu mjerenja koncentracije BNP-a (pri nižim koncentracijama interferenta dovodi do lažno povišenih, a pri višim do lažno sniženih vrijednosti analita). Utjecaj lipemije na određivanje mioglobina ovisan je o koncentraciji samoga analita u uzorku i zabilježen je kod viših koncentracije analita kada dovodi do lažno sniženih vrijednosti. Različiti načini uzrokovanja hemolize imaju za posljedicu i razlike u opaženom utjecaju interferencije hemolize na koncentraciju analita od interesa zbog čega je potreban oprez pri interpretaciji dobivenih rezultata.

Abstract (english)

The most significant clinical use of determing the concentration of B-natriuretic peptide (BNP), creatine kinase MB (CK-MB) and myoglobin is in the diagnosis of heart dysfunctions, for example heart failure and myocardial infarction. The aim of this research was to investigate methods of inducing hemolysis in serum samples and to verify immunochemical test for BNP, CK-MB and myoglobin measurement. The analytical verification included method imprecision investigation, lipemia interference on all three analytes and hemolysis interference on CK-MB measurement. We used residual serum or plasma samples of hospital patients admitted in the laboratory at The Clinical Institute of Chemistry KBC „Sestre milosrdnice“ in Zagreb. Hemolysis was analyzed using hemolysate and freezing the samples, while Intralipid® was added into the plasma or serum to simulate lipemic samples. The analytes were measured on Abbott Architect i2000 immunochemistry analyzer. Results of analytical verification showed that the imprecision of the method is in accordance with the manufacturer claims. Hemolysis and lipemia caused no significant change in the CK-MB measuring result. Lipemia interference affected BNP measurement causing false elevated results of the analyte at lower concentrations of interferent and false decreased values at higher concentrations of interferent. The effect on myoglobin measurement is dependent on the concentration of the analyte in the sample. Hemolysis could not be induced by mixing samples on the vortex or by their expulsion through the needle. Significant hemolysis was obtained by freezing and mixing samples with a homogenizer. In conclusion, the method imprecision is acceptable, hemolysis and lipemia do not affect CK-MB measurement, lipemia caused significant changes in BNP measurement results causing false elevated results of the analyte at lower concentrations of interferent and false decreased values at higher concentrations of interferent. The effect on myoglobin measurement is dependent on the concentration of the analyte in the sample and is recorded at higher analyte concentration when leads to falsely reduced values. Different methods of inducing hemolysis cause differences in the interference investigation results. The results should be interpreted with caution.

• Keywords: BNP; CK-MB; mioglobin; imunokemijski test; verifikacija; nepreciznost; lipemija; hemoliza; interferencije
• Keywords (english): BNP; CK-MB; myoglobin; immunoassay; verification; imprecision; lipemia; hemolysis; interference
• Language: croatian
• URN:NBN: urn:nbn:hr:163:440408
• Study programme: Title: Medical Biochemistry; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra medicinske biokemije (magistar/magistra medicinske biokemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2016-03-02 10:18:28