Department of Clinical Laboratory, Fudan University Shanghai Cancer Center, Shanghai, China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
J Eur Acad Dermatol Venereol. 2019 Jan;33(1):178-184. doi: 10.1111/jdv.15251. Epub 2018 Oct 12.
Currently, many laboratories have switched the traditional screening algorithm (TSA) to reverse screening algorithm (RSA) for the efficiencies in high-volume syphilis screening. However, confusions have been arisen regarding this paradigm shift.
To compare the performance of two algorithms with head-to-head mode.
Sera screening for syphilis were tested in parallel with chemiluminescence immunoassay (CIA) and toluidine red unheated serum test (TRUST). CIA-reactive sera from the RSA were reflexively tested with TRUST and confirmed with Treponema pallidum particle agglutination assay (TPPA), while the TRUST-reactive serology from the TSA were afterwards tested with TPPA.
A total of 110 663 serum samples were screened. The RSA identified 2259 (2.0%) CIA-reactive results, of which 377 (16.7%) showed TPPA nonreactive results, while the TSA identified 934 (0.8%) TRUST-reactive results, of which 67 (7.2%) showed TPPA-nonreactive results. Among the 2259 CIA-reactive results, 1392 (61.6%) were TRUST-nonreactive, of which 350 (25.1%) were TPPA-nonreactive. A total of 182 sera from the 350 TPPA-nonreactive sera were further tested by a second CIA (VITROS Syphilis TPA, VITROS TPA), of which 155 (85.2%) were nonreactive and 27 (14.8%) were reactive. The 27 VITROS TPA-reactive sera were further tested with a treponemal Western blot assay (Euroimmun IgG Western Blot, EuroWB), of which 11 (41%) were indeterminate, 6 (22%) were nonreactive and 10 (37%) were reactive. Among the 10 EuroWB-reactive sera, two seroconverted to TPPA 1:80+/- after 1-year follow-up. Of 867 CIA-reactive/TRUST-reactive results, 27 (3.1%) were TPPA-nonreactive.
The RSA identified more patients with reactive treponemal serology. However, it also yielded an increased likely false-reactive rate compared with the TSA, especially those results with low index values and TRUST-nonreactive serology, were necessary to retest with a second treponemal test. Further testing results with TPPA, VITROS TPA and EuroWB suggested the false-reactive CIA screening results and the likely false-nonreactive TPPA results when the reactive treponemal results screened with RSA were to be identified.
目前，许多实验室已将传统的筛查算法（TSA）切换为反向筛查算法（RSA），以提高大规模梅毒筛查的效率。然而，这种范式转变引起了一些困惑。
以头对头的模式比较两种算法的性能。
采用化学发光免疫分析（CIA）和甲苯胺红不加热血清试验（TRUST）平行检测梅毒血清筛查。RSA 中 CIA 反应性血清用 TRUST 进行反射性检测，并以梅毒螺旋体颗粒凝集试验（TPPA）进行确认，而 TSA 中 TRUST 反应性血清学检测后用 TPPA 进行检测。
共筛查了 110663 份血清样本。RSA 共检出 2259 份（2.0%）CIA 反应性结果，其中 377 份（16.7%）TPPA 非反应性结果，而 TSA 共检出 934 份（0.8%）TRUST 反应性结果，其中 67 份（7.2%）TPPA 非反应性结果。在 2259 份 CIA 反应性结果中，有 1392 份（61.6%）TRUST 非反应性，其中 350 份（25.1%）TPPA 非反应性。350 份 TPPA 非反应性血清中的 182 份血清进一步用第二种 CIA（VITROS 梅毒 TPA，VITROS TPA）进行检测，其中 155 份（85.2%）非反应性，27 份（14.8%）反应性。27 份 VITROS TPA 反应性血清进一步用梅毒螺旋体 Western blot 检测（Euroimmun IgG Western Blot，EuroWB），其中 11 份（41%）为不确定，6 份（22%）为非反应性，10 份（37%）为反应性。在 10 份 EuroWB 反应性血清中，有 2 份在 1 年随访后血清转阳至 TPPA 1:80+/-。在 867 份 CIA 反应性/TRUST 反应性结果中，有 27 份（3.1%）TPPA 非反应性。
RSA 鉴定出更多的梅毒螺旋体血清学反应性患者。然而，与 TSA 相比，它也产生了更高的可能假反应率，尤其是那些指数值较低和 TRUST 非反应性血清学的结果，需要用第二种梅毒检测进行重新检测。用 TPPA、VITROS TPA 和 EuroWB 进行进一步检测结果表明，当用 RSA 筛查出反应性梅毒螺旋体结果时，需要识别出假反应性 CIA 筛查结果和可能的假非反应性 TPPA 结果。
