RESUMEN
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.
RESUMEN
Pre-analytical quality in clinical chemistry testing is as important as analytical and post-analytical quality. The most prevalent pre-analytical interference and a major source of error producing unreliable laboratory test results is hemolysis of blood samples. In vitro hemolysis may be due to the blood withdrawal technique or sample handling whereas in vivo hemolysis can originate from acquired, hereditary, or iatrogenic conditions and is not technique dependent. Interpreting in vivo or in vitro hemolysis requires clinicians to supply reliable clinical history and findings. Even then, to reject or release the result with interpretation is still under debate. Thus, hemolyzed specimens are a serious pre-analytical problem calling for well-designed and strictly implemented laboratory guidelines. The aim of this non-systematic review (addressed to healthcare professionals) was to highlight the challenges in identifying and rejecting hemolysis specimens.