Abstract
The study compared two plasma procalcitonin (PCT) assays, the point of care (POC) Finecare™ Procalcitonin Rapid Quantitative Test and the Elecsys(®) BRAHMS PCT immunoassay, in sepsis ICU patients. Forty-one plasma samples were analyzed, showing a strong correlation (r = 0.98) and no significant difference in PCT values. The mean POC PCT value was 4.46 ng/mL (SD 8.68), and for laboratory BRAHMS PCT, it was 4.67 ng/mL (SD 10.03). The study found a strong linear relationship between plasma POC PCT and laboratory BRAHMS PCT (r = 0.98). Different regression methods showed varying intercepts and slopes: Ordinary Least Squares had an intercept of 0.49 and a slope of 0.85; Deming regression showed an intercept of 0.43 and a slope of 0.86; Passing-Bablok regression showed an intercept of 0.02 and a slope of 1.08. Precision results for cut-offs of 0.5 ng/mL were a coefficient of variation (CV) of 5%, and for 2.5 ng/mL, the CV was 2.5%. The Pearson correlation coefficient (r) for linearity was ≥0.99. The study revealed no significant difference between the POC Finecare™ PCT and Elecsys(®) BRAHMS PCT immunoassay in sepsis samples from ICU patients, supported by strong correlation, minimal bias, a consistent CV, and linearity.