Validation of the Procalcitonin Assay on the Abbott Architect i1000

Procalcitonin (PCT) is an emerging biomarker for detecting sepsis. Recently, the US Food and Drug Administration cleared the expanded use of this biomarker for guiding clinicians regarding antibiotic treatment. To our knowledge, there are no published method validations for the Abbott Architect PCT assay. This article will discuss the process of method validation of the B·R·A·H·M·S PCT assay on the Abbott Architect platform.

We studied the precision, accuracy, and linearity of the Architect method following the guidance of the Clinical and Laboratory Standards Institute EP5-A2 document. Furthermore, we also tested the impact of major sources of interference from hemolysate, lipoproteins, and bilirubin. To validate the Architect method, we compared patients' serum PCT measurements with our previously established Mini VIDAS (bioMerieux) PCT assay.

Statistical analysis showed that the 2 assays have good correlation (r > 0.99), slope of 1.023, and intercept of -0.760. The calculated bias is -7.435%. The Architect method showed good precision with %CV < 3.5% for both interassay and intraassay compared with %CV < 6.5% for Mini VIDAS, which was previously determined at our institution. No bias >10% was observed with the Architect method when pooled serum samples were spiked with interferants. The turnaround time for both platforms was the same (20 min); however, in contrast with Mini VIDAS, the Architect system has automated pipetting of samples and can perform multiple assays simultaneously.

These results showed that the Architect B·R·A·H·M·S PCT assay has analytical characteristics conducive for diagnostic use in clinical laboratories. Our method validation report will be beneficial for other institutions to adapt this assay on existing Abbott Architect i1000 immunoassay analyzers.