A longitudinal evaluation of performance of automated BCR-ABL1 quantitation using cartridge-based detection system. Issue 6 (October 2015)

• Record Type: Journal Article
• Authors: Enjeti, Anoop; Granter, Neil; Ashraf, Asma; Fletcher, Linda; Branford, Susan; Rowlings, Philip; Dooley, Susan
• Is Part Of: Pathology. Volume 47:Issue 6(2015:Oct.)
• Publication Date: 2015-10
• Subjects: Pathology -- Periodicals; 616.0705
• DOI: 10.1097/PAT.0000000000000293
• Languages: English
• ISSNs: 0031-3025

Abstract

<abstract> <title> <x xml:space="preserve">Abstract</x> </title> <sec> <title>Summary</title> <p>An automated cartridge-based detection system (GeneXpert; Cepheid) is being widely adopted in low throughput laboratories for monitoring BCR-ABL1 transcript in chronic myelogenous leukaemia. This Australian study evaluated the longitudinal performance specific characteristics of the automated system.</p> <p>The automated cartridge-based system was compared prospectively with the manual qRT-PCR-based reference method at SA Pathology, Adelaide, over a period of 2.5 years. A conversion factor determination was followed by four re-validations. Peripheral blood samples (<italic>n</italic> = 129) with international scale (IS) values within detectable range were selected for assessment. The mean bias, proportion of results within specified fold difference (2-, 3- and 5-fold), the concordance rate of major molecular remission (MMR) and concordance across a range of IS values on paired samples were evaluated.</p> <p>The initial conversion factor for the automated system was determined as 0.43. Except for the second re-validation, where a negative bias of 1.9-fold was detected, all other biases fell within desirable limits. A cartridge-specific conversion factor and efficiency value was introduced and the conversion factor was confirmed to be stable in subsequent re-validation cycles. Concordance with the reference method/laboratory at >0.1–⩽10 IS was 78.2% and at ⩽0.001 was 80%, compared to 86.8% in the >0.01–⩽0.1 IS range. The overall and MMR concordance were 85.7% and 94% respectively, for samples that fell within ± 5-fold of the reference laboratory value over the entire period of study.</p> <p>Conversion factor and performance specific characteristics for the automated system were longitudinally stable in the clinically relevant range, following introduction by the manufacturer of lot specific efficiency values.</p> </sec> </abstract>