Research on HBsAg negative samples with high value / 国际检验医学杂志

ABSTRACT

Objective To study the situation of missing detection of HBsAg negative samples with high value and to explore the ways for reducing the missing detection .Methods According to the document EP15-A2 issued by the Clinical and Laboratory Standards Institute(CLSI) ,the precision and accuracy of the HBsAg quantitative detection by the ARCHITECT I 2000 were verified for ensuring the instrument conditions conforming to the test requirements .The 1 130 samples with the ratio of the sample absor-bance value to critical value(S/CO) in the range 0 .30-0 .99 in the HBsAg qualitative results by ELISA were collected during the study period and re-tested .After re-testing ,the quantitative HbsAg of 387 samples ,in which the ratio of S/CO was still in the range 0 .30-0 .99 ,were detected by the ARCHITECT I2000 and the detection results were taken as the reference .The missing detection situation of HBsAg negative samples with high value was researched .The ROC curve was adopted to reassess the cutoff value of negative HBsAg with positive HbcAb for searching better diagnostic performance .Results The HBsAg detection results by the i2000SR had good repeatability with total imprecision of less than 9 .88% and the deviation value with calibrator was less than 3 .91% ,which conformed to the clinical testing requirements .This study found that the HBsAg samples with the S/CO ratio of 0 .30-0 .99 had the significant distribution differences in the different batches of test (P<0 .05) .In the study period ,261 cases of HBsAg missing detection occurred ;then the critical value of HBsAg qualitative results detected by ELISA in the HbcAb positive group was re-determined as 0 .51 by using the ROC curve ,among them 239 cases were rejudged as positive .Conclusion Increasing the repeatability of HBsAg qualitative detection by ELISA and establishing the new positive judgement value of ELISA for qualita-tive HBsAg in the HbcAb positive population as 0 .51 possesses better diagnostic performance for detection the HBsAg samples with the S/CO ratio of 0 .30-0 .99 .