Establishment and performance evaluation of the quantitative detection for procalcitonin based on fluorescence immunochromatography / 中华检验医学杂志

ABSTRACT

Objective To develop a quick quantitative detecting method for point of care testing (POCT) of human serum procalcitonin (PCT) by fluorescence immunochromatographic technology.Methods Applying a double-antibody sandwich immunofluorescent assay (one antibody coated on the nitrocellulose membrane and the other antibody labeled with fluorescent micropaticles) to develop a PCT quantitative detecting kit by immunochromatography technology.The kit was used to test PCT in 472 serum samples from suspected bacterial infection patients of Guangzhou Red Cross Hospital,including 240 male and 232 female patients.The methodology and diagnostic performance were evaluated in the aspects of linearity,precision,accuracy,specificity,stability experiments and comparison with foreign PCT detecting kits.Results The report range of the PCT quantitative diagnostic kit was 0.1-125.0 μg/L The coefficient of variation (CV)values of repeat 20 tests for low,median,and high concentration control samples respectively were all less than 15％ and bias can be acceptable (P ＞ 0.05).Common interfering substances in human serum specimens such as bilirubin (2.0 g/L),triglyceride (30.0 g/L) and cholesterol (15.0 g/L) were found no significant affect on quantitative detection of PCT.The shelf time of the PCT diagnostic kit should be longer than 12 months as the relative deviation of detected concentrations of 0.5,1.0,22.0,65.0 μg/L PCTcontrol sample can be controlled less than 20％ within 14 months.Considering VIDAS BRAHMS PCT to be the standard quantitative test for PCT,472 serum samples were detected by both our kit and the control VIDAS BRAHMS PCT kit simultaneously,which showed high correlation (YVIDAS =0.180 + 1.006Xwondfo,R2 =0.988,P ＜ 0.01) and low deviation (Z =-1.6,P ＞ 0.05) without statistic significance between two methods.And the results of these two diagnostic kits showed good consistency as the area under curve of the receiver operating characteristic (ROC) of Wondfo-PCT at the three cut-off values (0.5,2.0,10.0 μg/L)were 0.997,0.994,0.998 respectively,P ＜ 0.01,using diagnostic result of the control product as standard.Kappa values were 0.899,0.905,0.973 respectively.Conclusions The method of quantitative detection of PCT by fluorescence immunochromatography for POCT was established in this study.All the observed indicators reached the clinical diagnostic requirements and can be applied for the quick detection of clinical human serum PCT.