用ELISA夹心法检测尿标本中的巨细胞病毒抗原

DETECTION OF CYTOMEGALOYIRUS ANTIGEN IN URINE SAMPLES BY SANDWICH ELISA

Goats were immunized with a mixture containing cell-free culture fluid of CMV AD169 ( 105.5TCID50/ml) concentrated by precipitation with polyethlene glycol ( pEG ) and an equal volume of Freund's complete adjuvant. The antisera obtained from goats had high titer antibody to CMV, which was detected by ELISA ( 1 : 25,600 ), neutralization ( 1 : 1,024 ), complement fixation ( 1 : 1,024), and immunofluorescence ( 1 : 640 ) tests. These antisera did not react with other Herpes virus ( HSV1, HSV2, VZV and had low reactivity with human host cell components in ELISA and CF tests. After absorption with host cell components and purification with QAE-Sephadex A50, this nonspecific reaction was removed. An enzyme-linked immunosorbent assay ( ELISA ) was developed for detecting CMV antigen using purified Ig G as capturing antibody. CMV can be detected at titer of 101.69TCID50/ml. Then we used the ELISA for examination of CMV in urine specimens from 79 normal infants of 6-36 months, among whom CMV-Ag was found in 19 cases ( 24.05%). 11 of 12 culture-positive samples were positive also by ELISA ( sensitivity 91.6%). 26 urine specimens from patients suspected as active CMV infection were also examined. 15(57.69%)were CMV-Ag positive and 13 of 14 culture-positive samples were detected by ELISA ( sensitivity 92.86%). From a total of 105 samples examined there were 10 positive by ELISA but negative in cell culture. All of the 10 samples were obtained from patients with evidence of actire CMV infection. Among them 3 had CMV IgM antibody alone, 2 had both CMV-IgM and CMV-IgA antibodies, one case was CMV-IgA positive and 3 patients had antibody to CMV-IgG with high titer ( 1:1,600 in ELISA). In another patient CMV was isolated two weeks later. ELI-SA-blocking tests showed that all 10 samples were positive.