高速离心对传染病四项复检结果的影响

Effect of High Speed Centrifugation on the Retesting Results of Serum Markers of Four Blood-Borne Infectious Diseases

目的观察高速离心对HBs Ag、HIV-Ag/Ab、抗-HCV、TP-Ab复检结果的影响。方法收集HBs Ag、HIV-Ag/Ab、抗-HCV、TP-Ab四项初检低值阳性样本,分别采用低速离心和高速离心分离血清,然后进行复检并对复检结果进行比较。结果经低速离心和高速离心后复检,HBs Ag的复检阳性率分别是58.62%和27.59%,存在显著性差异(χ2=5.069,P=0.017),HIVAg/Ab的复检阳性率分别是34.78%和8.70%,存在显著性差异(χ2=4.600,P=0.032),抗-HCV的复检阳性率分别是79.17%和75.00%,不存在显著性差异(χ2=0.118,P=0.731),TP-Ab的复检阳性率分别是96.00%和92.00%,不存在显著性差异(χ2=0.355,P=0.552);低速离心后复检阳性样本68例经高速离心后的复检阳性率为69.12%(47/68),低速离心后复检阴性样本33例经高速离心后的复检阴性率为87.88%(29/33);低速离心后夹心法检测项目和间接法检测项目的复检阳性率分别为48.08%和87.26%,存在显著性差异(χ2=18.055,P<0.001),高速离心后夹心法检测项目和间接法检测项目的复检阳性率分别为19.23%和83.67%,存在显著性差异(χ2=41.911,P<0.001),提高离心速度后夹心法检测项目和间接法检测项目的复检阳性率分别下降了28.85%和3.59%,存在显著性差异(χ2=8.246,P=0.004)。结论提高离心速度可以明显降低HBs Ag和HIV-Ag/Ab的复检阳性率;HBs Ag、HIV-Ag/Ab、抗-HCV、TP-Ab低值阳性时经低速离心后复检存在假阳性和假阴性,免疫学方法不同的项目其复检阳性率存在明显差异,提高离心速度对夹心法检测项目的复检结果有明显影响。

Objective To explore the effect of high speed centrifugation on the retesting results of serum markers of four blood-borne infectious diseases. Methods The blood samples with low initial testing-value were collected, in which there were 29 samples with HBsAg between 0. 05-0. 20mIU/L,23 samples with HIV-Ag/Ab between 1-2S/CO,24 samples with anti-HCV 1-2S/CO, and 25 samples with anti-TP 1-2S/CO. The blood samples were separated at low and high centrifugation speed respectively in order to be redetected. The retesting results were compared in each item-group and among two method-groups. Results All samples were centrifuged at low speed and high speed respectively and then retested. The positive rates of HBsAg were 58.62% and 27.59% respectively and had significant difference （x2 = 5. 069 ,P = 0. 017）. The positive rates of HIV-Ag/Ab were 34.78% and 8.70% respectively and had significant difference （X2 = 4. 600, P = 0. 032 ）. The positive rates of anti-HCV were 79.17% and 75.00% respectively and had no significant difference （x2 = 0. 118 ,P = 0. 731 ）. The positive rates of anti-TP were 96.00% and 92.00% respectively and had no significant difference （X= = 0. 355, P = 0. 552）. Among the 68 positive samples and 33 negative samples which all were retested after low speed centrifugation, the false positive rate and false negative rate were 30.88% （21/68）and 12. 12%（4/33） respectively. With low speed centrifugation, the retesting positive rates were 48.08% in the sandwich- method group and 87.26% in the indirect-method group,and the difference was significant （x2 = 18. 055 ,P = 0.000）. With high speed centrifugation, the retesting positive rates were 19.23% in the sandwich-method group and 83.67% in the indirect-method group, and the difference was also significant （X2 = 41. 911, P = 0. 000）. As the speed increasing, the retesting positive rates among sandwich-method group and indirect- method group decreased 28. 85% and 3.59% and had significant difference （X2 = 8. 246, P = 0. 004）. Conclusion High speed centrifugation could significantly decrease the retesting positive rate of HBsAg and HIV- Ag/Ab. The low speed centrifugation could cause false positive and false negative. The effect of centrifugation speed on the retestirlg results differs between sandwich-method and indirect-method.