Commutability Assessment of Candidate Reference Materials for Pancreatic α-Amylase

Area of Science:

• Clinical Chemistry
• Biomarker Standardization
• Laboratory Medicine

Background:

• Standardization of serum α-amylase catalytic concentration relies on primary reference measurement procedures (PRMP), reference laboratories, and certified reference materials (CRMs).
• Commutability of CRMs is essential for accurate calibration, trueness control, and value transfer in routine diagnostic methods.

Purpose of the Study:

• To evaluate the commutability of candidate reference materials (RMs) for pancreatic α-amylase using various routine methods.
• To compare different approaches for assessing commutability.

Main Methods:

• A commutability study was conducted using 30 serum pools and 5 candidate RMs (4 artificial matrix, 1 human serum).
• An automated primary reference measurement procedure (PRMP) and 5 routine methods were employed.
• Data analysis followed linear regression with prediction intervals (CLSI EP30-A) and IFCC Working Group recommendations for difference in bias.

Main Results:

• Candidate RMs with artificial matrices showed variable commutability profiles.
• One artificial matrix RM containing human serum albumin demonstrated a commutability profile similar to the human serum-based RM.
• Discrepancies were observed between commutability assessment approaches, with the difference in bias method yielding inconclusive results and indicating uncertainty.

Conclusions:

• Certified reference materials (CRMs) for pancreatic amylase in artificial matrices can achieve commutability with routine methods sharing the same substrate as the PRMP.
• The composition of the artificial matrix, particularly the inclusion of human serum albumin, is critical for ensuring commutability.