Naslov
Stability of enzyme activities in serum sample – alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and their activated forms (aALT, aAST)

Autori
Brenčić, Tina ; Topić, Anita ; Nikolac, Nora

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, stručni

Izvornik
Clinical Chemistry and Laboratory Medicine / - , 2017, A31-A31

Skup
4th EFLM-BD European Conference on Preanalytical Phase – Improving Quality of Preanalytical Phase through inovation

Mjesto i datum
Amsterdam, Nizozemska, 24.03.2017. - 25.03.2017

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
preanalytical phase ; sample stability ; AST ; ALT

Sažetak
Background: Activated alanine aminotransferase (aALT) and activated aspartate aminotransferase (aAST) are IFCC recommended methods with pyridoxal-6-phosphate as a reaction activator, unlike ALT and AST. Manufacturer declares the stability of serum sample for enzyme activity at room temperature and 4°C without specification of sample type (primary tube or aliquot). The aim of this study was to evaluate stability of aALT, ALT, aAST and AST in primary tube and aliquot at both temperatures. Materials and methods: Study was carried out in University Department of Chemistry, Medical School University Hospital Sestre Milosrdnice (Zagreb, Croatia) from May to June 2016. Manufacturer’s declared stabilities are: ALT, aALT: 3 days ; AST, aAST: 4 days at room temperature and ALT, aALT ; AST, aAST- 7 days at 4°C. Four serum samples were used for the study: aliquoted serum sample stored at room temperature and at 2-8°C and serum sample in primary tube at both temperatures. Enzyme activities were measured daily during 10 days in duplicate on Architect c8000 analyser (Abbott, Illinois, USA) using original reagent kits. Mean value between two measurements and bias(%) for each sample regarding the initial activity was calculated. Acceptance criteria was defined as external quality control criteria (ALT, aALT- 12% ; AST, aAST- 15%). Results: Enzyme stability for ALT and aAST confirmed manufacturer’s declarations. aALT activity didn’t meet acceptance criteria: it was stable 1 day (aliquoted sample, day 2 bias = 33.3%) and 4 days (primary tube ; day 5 bias = -12.7%) at room temperature and 6 days (aliquoted sample, day 7 bias -15.6% ) at 2- 8°C, while the activity in primary tube at 2- 8°C wasn’t changed during the tested period. In primary tube sample at room temperature, AST activity was stable 3 days (day 4 bias = 18.3%). Conclusion: ALT and aAST are more stable enzymes than aALT and AST. Enzymes are stable longer when samples are stored at 2-8°C.

Izvorni jezik
Engleski

Znanstvena područja
Kliničke medicinske znanosti

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