Sandin R L, Knapp C C, Hall G S, Washington J A, Rutherford I
Department of Microbiology, Cleveland Clinic Foundation, Ohio 44195.
J Clin Microbiol. 1991 Dec;29(12):2763-7. doi: 10.1128/jcm.29.12.2763-2767.1991.
The value and convenience of testing for specific anti-Toxoplasma gondii antibodies have led to the development of various antibody detection methods, such as the enzyme immunoassay. Two enzyme immunoassays, the Vitek Immuno-Diagnostic Assay System (VIDAS; Vitek Systems, Hazelwood, Mo.) and the Toxostat Test Kit (TST; Whittaker Bioproducts, Walkersville, Md.), were compared for their ability to detect T. gondii immunoglobulin G antibodies in fresh human sera. Specimens were tested according to the instructions of each manufacturer. Of 304 serum specimens tested, the results for 282 (93%) agreed in both assays (77 were positive and 205 were negative). The results for the remaining 22 (7%) specimens were discrepant; 20 of the 22 specimens tested low positive or equivocal by Toxostat and negative by VIDAS. Upon retesting, 8 of these 22 specimens were in concordance, increasing the level of agreement to 95.3%. Intra-assay reproducibility was tested with four to nine replicates of each of seven samples (four positive, one negative, and two equivocal) by both tests and six replicates of one standard by VIDAS. Coefficients of variation (CVs) for VIDAS were 6, 8, 10, 15, 18, 19, and 23% for the samples and 14% for the standard. For Toxostat the CVs were 2, 8, 10, 10, 13, and 16%. In general, CVs for VIDAS were slightly larger than the CVs for Toxostat. Day-to-day variability over 3 days was tested by VIDAS for only six samples (three positive, two negative, and one equivocal) and four standards; CVs ranged from 2 to 15% for the samples and from 6 to 13% for the standards. In conclusions, VIDAS is a rapid, convenient, non-labor-intensive, and easily performed test for the detection of immunoglobulin G antibodies to T. gondii in serum specimens.
检测特定抗弓形虫抗体的价值和便利性促使了多种抗体检测方法的发展，如酶免疫测定法。对两种酶免疫测定法，即维德免疫诊断测定系统（VIDAS；维德系统公司，密苏里州黑兹尔伍德）和弓形虫检测试剂盒（TST；惠特克生物制品公司，马里兰州沃克尔斯维尔）检测新鲜人血清中弓形虫免疫球蛋白G抗体的能力进行了比较。按照各制造商的说明对标本进行检测。在检测的304份血清标本中，两种测定法的结果在282份（93%）标本中一致（77份为阳性，205份为阴性）。其余22份（7%）标本的结果不一致；这22份标本中有20份经弓形虫检测试剂盒检测为弱阳性或不确定，而经VIDAS检测为阴性。重新检测后，这22份标本中有8份结果一致，使一致率提高到95.3%。两种检测方法都对7个样本（4个阳性、1个阴性和2个不确定）各进行了4至9次重复检测，以测试批内重复性，VIDAS还对1个标准品进行了6次重复检测。VIDAS对样本的变异系数（CV）分别为6%、8%、10%、15%、18%、19%和23%，对标准品的变异系数为14%。对于弓形虫检测试剂盒，变异系数分别为2%、8%、10%、10%、13%和16%。总体而言，VIDAS的变异系数略大于弓形虫检测试剂盒的变异系数。VIDAS仅对6个样本（3个阳性、2个阴性和1个不确定）和4个标准品进行了3天的日间变异性检测；样本的变异系数在2%至15%之间，标准品的变异系数在6%至13%之间。总之，VIDAS是一种快速、便捷、无需大量人力且易于操作的检测血清标本中弓形虫免疫球蛋白G抗体的方法。
