A Corrective Method for Different Hematocrit Values of Whole Blood Samples on the Detection of Procalcitonin

We have explored that quantitative PCT detection can be conducted in different sample types (whole blood and/or plasma samples) with good correlation and consistency in clinical use. These findings reduce the sample volume and turnover time of PCT detection in clinical labs. However, different hematocrit (HCT) percentages of whole blood samples may affect the final results, especially abnormal hematocrit (HCT) percentages. To overcome this problem, we established a mathematical model to modify the whole blood test results and evaluated the effects of HCT correction.

First, we prepared a preliminary experiment - various hematocrit (HCT) percentages (15% - 65%) of whole blood samples with different PCT concentrations and established a mathematic model to correct the effects of PCT detection. Then, in this paper, we evaluated the consistency with Pearson's correlation and Kappa analysis between whole bloods detected by the i-Reader S system and plasma detected by the Biomerieux system. Besides, we prepared different HCT values about 15%, 40%, 60% of 9 samples with different PCT concentrations to evaluate the effects of HCT correction Results and Conclusions: Pearson's correlative studies and Kappa analysis indicated that PCT levels measured by i-Reader S (plasma & whole blood samples) were comparable to results from the VIDAS system, and HCT correction could improve consistency of PCT detection between whole blood and plasma. Analysis of samples with abnormal HCT values showed that the mathematical correction model could offset the influences of various HCT values.