A-051 Validation and Implementation of the Stanbio Beta-Hydroxybutyrate Assay on Roche c502 Analyzer

Abstract Background β-hydroxybutyrate (βOHB) serves as a crucial biomarker in assessing, managing, and monitoring ketosis in various clinical scenarios, such as diabetic ketoacidosis and instances of alcohol abuse combined with starvation. This study aimed to validate a βOHB assay (Stanbio Laboratory) conducted on a Roche Cobas c502 analyzer and establish performance specifications. Additionally, we conducted a method comparison for three assays: Randox D-3-Hydroxybutyrate (Ranbut) assay on Roche c501 analyzer, Abbott Freestyle Precision B-Ketone strip point-of-care test, and the Stanbio Laboratory β-Hydroxybutyrate LiquiColor assay on Roche c502 analyzer. Methods Precision, linearity, limit of quantification (LOQ), method comparison, and sample stability were determined according to Clinical and Laboratory Standards Institute (CLSI) guidelines, using commercial quality control materials (Randox Multisera) and residual patient samples (Lithium heparin anti-coagulated plasma). The reference interval was verified by residual samples from 20 healthy individuals (normal blood glucose, HbA1c, liver enzymes, and lipid panel results). Statistical analysis was performed by EP-Evaluator (v12). Results Intra-assay and total coefficient of variation (CV) were determined as 0% and 2.4% at 0.3 and 1.21 mmol/L, respectively. The linearity range of the assay was verified from 0.0 to 9.0 mmol/L. Using CV < 20% as criteria, the functional sensitivity (LOQ) was 0.10 mmol/L at least. Lithium heparin anti-coagulated plasma specimens were stable for 24 hours at room temperature or seven days at 4 - 8 ̊C. The manufacturer’s reference interval was verified as 0.00 - 0.40 mmol/L. The Stanbio βOHB assay on the Roche c502 analyzer demonstrated a strong agreement with the Randox D-3-Hydroxybutyrate assay on the Roche c501 analyzer with a slope of 1.053 (95% CI: 1.037, 1.070) and intercept of -0.005 (95% CI: -0.068, 0.059) (coefficient correlation R = 0.9992). A positive bias was observed compared to the Abbott Freestyle Precision B-Ketone strip POC test (mean bias = + 0.50 mmol/L; slope = 1.630, 95% CI: 1.404, 1.857; R = 0.9184), and this discrepancy occurred particularly at βOHB > 5.5 mmol/L measured by Abbott method. Conclusions The Standbio βOHB assay exhibited excellent precision and linearity across a brand range of concentrations. This assay strongly agrees with the Randox assay run on a similar instrument but discordance with Abbott’s POCT method at high βOHB concentration. Overall, the validated method provides a reliable and efficient means for measuring βOHB levels on a Roche chemistry analyzer, facilitating accurate diagnosis and monitoring of ketosis-related conditions in clinical settings.