Department of Infectious Diseases and The Albion Centre, Prince of Wales Hospital and Prince of Wales Clinical School, University of New South Wales, Randwick, New South Wales, Australia.
School of Psychiatry, University of New South Wales, Sydney, New South Wales, Australia.
Sex Transm Infect. 2018 May;94(3):187-191. doi: 10.1136/sextrans-2017-053284. Epub 2017 Oct 11.
The significance of sera with isolated reactive treponemal chemiluminescence immunoassay (IRTCIA) results is unclear. Women have this phenotype more commonly than men. Most cohorts examining this phenotype have included predominantly men and have demonstrated evidence of past or subsequently confirmed syphilis infection in a significant proportion of cases. We hypothesised that a proportion of sera with IRTCIA results would be positive on immunoblot testing and that sera from women with IRTCIA would have different results in immunoblot testing than men.
IRTCIA sera from a tertiary referral serology laboratory serving multiple clinical sites were analysed with a syphilis line immunoblot assay (LIA) and analysed by sex. Logistic regression was undertaken to assess factors associated with LIA status. Medical record review and descriptive analysis of a separate cohort of women with the IRTCIA phenotype from a single campus was also undertaken.
Overall, 19/63 (30.1%) subjects with the IRTCIA phenotype were positive in the LIA, including 13 men and 6 women. Women were significantly less likely to have definitive results (positive or negative) than men (p=0.015). Pregnant women were less likely than non-pregnant women to have a negative LIA result (OR 0.57; p=0.03). Record review of 22 different women with IRTCIA reactivity showed that 2/22 (9.1%) had HIV and previous syphilis infection, 15/22 (68.2%) were pregnant and 3 (13.6%) had autoimmune disease.
A significant proportion of sera with IRTCIA results on serological tests are reactive on LIA testing and some may not be false positive results. The interpretation of IRTCIA results should be undertaken in conjunction with an assessment of factors such as sex, pregnancy, a history of syphilis and other STIs and syphilis risk.
血清中单独出现反应性密螺旋体化学发光免疫分析（IRTCIA）结果的意义尚不清楚。女性比男性更常出现这种表型。大多数检查这种表型的队列主要包括男性，并且在很大比例的病例中都有过去或随后证实的梅毒感染的证据。我们假设一部分具有 IRTCIA 结果的血清在免疫印迹检测中呈阳性，并且具有 IRTCIA 的女性的血清在免疫印迹检测中的结果与男性不同。
对来自多个临床站点的三级转诊血清学实验室的 IRTCIA 血清进行分析，使用梅毒线免疫印迹检测（LIA）进行分析，并按性别进行分析。采用逻辑回归评估与 LIA 状态相关的因素。还对来自单个校区具有 IRTCIA 表型的女性的另一队列进行了病历回顾和描述性分析。
总体而言，19/63（30.1%）具有 IRTCIA 表型的受试者在 LIA 中呈阳性，包括 13 名男性和 6 名女性。女性出现明确结果（阳性或阴性）的可能性明显低于男性（p=0.015）。与非孕妇相比，孕妇的 LIA 阴性结果的可能性较低（OR 0.57；p=0.03）。对 22 名不同具有 IRTCIA 反应性的女性的记录进行回顾，发现 2/22（9.1%）患有 HIV 和既往梅毒感染，15/22（68.2%）为孕妇，3 名（13.6%）患有自身免疫性疾病。
在血清学检测中，具有 IRTCIA 结果的血清中，有相当一部分在 LIA 检测中呈反应性，其中一些可能不是假阳性结果。IRTCIA 结果的解释应结合评估因素，如性别、怀孕、梅毒史和其他性传播感染以及梅毒风险。
