Application of ELISA in Detecting Heparin-Induced Thrombocytopenia Antibodies / 现代检验医学杂志

ABSTRACT

Objective To develop an ELISA method for determination of heparin-induced thrombocytopenia (HIT)antibody. Methods The compound formed between human platelet factor 4 (PF4)and heparin was used as the coating antigen,incu-bating the patients plasma with the coating antigen in the well,after washing,the second antibody labeled HRP was added in the well to incubate and washing again,the chromogenic substrates was added in the well to incubate,when the stop reaction was finished,the absorbance A450/A630 was detected,and the test results were judged according to standard,this method was compared with IBL method and was optimized and evaluated the performance.Results An indirect ELISA method was de-velop with the purified human PF4,the optimal dilution of sample and second antibody were 1∶100 and 1∶1 500 which de-tected by the orthogonal test,the intra-and inter-assay average coefficients of variation were 7.66% and 7.76%(<10%) respectively that detected by repeated measurement the three positive standard plasma.Through measureing the 100 healthy human plasm with no history of using heparin,the positive and negative predictive reference values were 0.304 and 0.456. IBL and this method detected 100 hemodialysis patients samples at the same time,and the result of statistical analysis was that,the sensitivity,speciality and accuracy of this method were 90%,97.78% and 90%,respectively.The negative and posi-tive predictive value were 81.8% and 98.88% respectively,and the difference was statistically significant [K=0.84(0.81~1)and Pexac=0.012<0.05].The difference was statistically significant,consistency was optimal,95% confidence interval was 92.59%~92.59%.Conclusion Comparing with the IBL,the method reported by this article had the similar perform-ance and good consistency,and it could satisfy the clinical detection and diagnosis of HIT patients.