Using of Certified
Reference Material IRMM/IFCC-456 (alpha Amylase, Total, 37 °C) for Standardization
of Measurement of alpha-Amylase by Direct Routine Method (CNP/G3, IFCC, 37 °C)
Dubská L.1, Kohelová B.1, Hyánek J.1, Sedlák P.2, Tichý M.3, Bullawa R.4
1Oddělení klinické biochemie, hematologie a imunologie, Nemocnice Na Homolce, Praha 5 2Oddělení klinické biochemie,MN Čáslav3II. interní klinika FN, Hradec Králové4BLW, s. s r. o., Praha |
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Summary:
In order to achieve easy transferability of patient results among the health care centers from the local up to
the international level, a transition process of clinical laboratory to the newlyrecommended IFCC alpha-amylase
reference ranges is necessary. The aim of our study was to explore the benefits of using certified reference
material (CRM IRMM/IFCC-456 Alpha Amylase, total) as a direct calibrator for adapted IFCC method for
measurement of α-amylase at 37 °C under routine laboratory conditions.
We used an adapted IFCC method at 37 °C (CNP-G3) (BLW Diagnostics) applied to Beckman Synchron LX 20,
Dimension AR (Dade Behring) and Hitachi 911 (Roche) clinical chemistry systems for α-amylase measurements.
Applied measurement conditions were modified with respect to given technical limits of the analyzers (temperature
37 °C and substrate start procedure, the same for all instruments); wavelength: 410nm (Synchron LX20),
405nm (Dimension AR), 415nm (Hitachi 911); preincubation time: 60 s, 65 s, 300 s; measurement interval: 30–120
s in all instruments).
For calibration purposes certified reference material IRMM/IFCC-456 (Alpha Amylase, total), IRMM, Geel,
Belgium was used.
Precision (within series) of the method was studied at concentration levels 1.2 µkat/l and 6.7 µkat/l: CV (LX20)
= 4.4 %, and 2.2 %, CV (Dimension) = 0.6 %, and 0.4 %, CV (Hitachi) = 0.8 %, and 0.9 %.
Precision (day to day) was followed at concentration levels 1.2 a 6.7 µkat/l for 20 days on SynchronLX 20 system:
CV (LX20) = 4.2 % and 3.5 %; and on Dimension AR for 10 days at concentration levels of 0.58, 0.82, 1.11, 1.48 a 14.88 µkat/l: CV (AR) = 3.66 %, 1.97 %, 1.20 %, 2.03 % and 0.56 %.
We transferred the IFCC reference method value of α-amylase from CRM using adapted IFCC method at 37 °C
(CNP-G3) to the control materials MultiCON 1, BLW (lot. B08101, lot. B10103), MultiCON 2, BLW (lot. B08201, lot.
B10203), Lyphochek assayed control level 1, BioRad (lot.14091) a Lyphochek assayed chemistry control level 2,
BioRad (lot. 14092).
With the measurement procedure standardized on CRM IRMM/IFCC-456 we compared mean value and reference
ranges of α-amylase values (CNP-G3, 37 °C) for the population of 60, resp. 68 healthy men (measured on
Synchron LX 20, resp. Hitachi 911) with the literature data (identical measurement principle, direct calibration
on CNP). Sample election has been chosen according to the same selection criteria. We observed median 0.83
µkat/l, or 0.91 µkat/l versus 0.87 µkat/l, 0.95 reference range 0.44–1.45 µkat/l, or 0.35–1.56 µkat/l versus 0.50–1.50
µkat/l.
Conclusion: Standardized reagent kit for α-amylase determination (CNP-G3, adapted IFCC, 37 °C) from BLW
Diagnostics in association with CRM IRMM/IFCC-456 (Alpha Amylase Total, IFCC, 37 °C) applied on clinical
chemistry systems Synchron LX20 (Beckman Coulter), Dimension AR (Dade Behring) and Hitachi 911 (Roche)
verified comparability of results from different laboratories. This arrangement allows the clinical laboratory
comply to fully with IFCC recommendations to implement new reference ranges for α-amylase values in patient
samples.alpha-amylase, routine method CNP-G3 (37 °C), IRMM/IFCC-456.
Key words:
alpha-amylase, routine method CNP-G3 (37 °C), IRMM/IFCC-456.
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