Abstract：
BACKGROUND: In the majority of clinical environments, the treponema pallidum particle agglutination (TPPA) test is known for its higher specificity compared to the rapid plasma reagin (RPR) test and is commonly employed for the diagnosis of syphilis, but their use for serological monitoring after syphilis therapy is controversial.
OBJECTIVE: We aim to evaluate whether the TPPA titers is suitable for monitoring syphilis treatment efficacy.
METHODS: At first, 232 patients with primary syphilis were recruited. Serological testing was performed at baseline (initial visit) and at 6 months (±1 month) after benzathine penicillin G (BPG) treatment. Second, New Zealand white male rabbits were infected with Treponema pallidum (T. pallidum) to evaluate the changes in TPPA titers after BPG therapy. Finally, we compared the TPPA titers in the culture supernatant of rabbit splenocytes stimulated with T. pallidum with or without BPG.
RESULTS: After 6 months of treatment, 150 (64.7%) of 232 primary syphilis patients achieved serological cure, and 82 (35.3%) had adverse outcomes. Among 110 patients with TPPA titers decreased by more than fourfold, 109 of them were serological cure patients (≥4-fold decrease in RPR titers) (P ＜ 0.0001). In the rabbit model of syphilis, the TPPA titers was significantly decreased in the treatment subgroup (P = 0.016) and remained constant (±2-fold) or increased (≥4-fold) in the nontreatment subgroup. In addition, T. pallidum resulted in a positive TPPA titers in the culture supernatant of splenocytes (median titers was 1: 80), while BPG could directly reduce the TPPA titers in the culture supernatant (median titers was 1: 40) (P = 0.032).
CONCLUSIONS: A 4-fold or greater decrease in TPPA titers may indicate effective treatment in primary syphilis. Combining TPPA titers with RPR titers results may potentially aid in the early diagnosis of syphilis.
OBJECTIVE: We aim to evaluate whether the TPPA titers is suitable for monitoring syphilis treatment efficacy.
METHODS: At first, 232 patients with primary syphilis were recruited. Serological testing was performed at baseline (initial visit) and at 6 months (±1 month) after benzathine penicillin G (BPG) treatment. Second, New Zealand white male rabbits were infected with Treponema pallidum (T. pallidum) to evaluate the changes in TPPA titers after BPG therapy. Finally, we compared the TPPA titers in the culture supernatant of rabbit splenocytes stimulated with T. pallidum with or without BPG.
RESULTS: After 6 months of treatment, 150 (64.7%) of 232 primary syphilis patients achieved serological cure, and 82 (35.3%) had adverse outcomes. Among 110 patients with TPPA titers decreased by more than fourfold, 109 of them were serological cure patients (≥4-fold decrease in RPR titers) (P ＜ 0.0001). In the rabbit model of syphilis, the TPPA titers was significantly decreased in the treatment subgroup (P = 0.016) and remained constant (±2-fold) or increased (≥4-fold) in the nontreatment subgroup. In addition, T. pallidum resulted in a positive TPPA titers in the culture supernatant of splenocytes (median titers was 1: 80), while BPG could directly reduce the TPPA titers in the culture supernatant (median titers was 1: 40) (P = 0.032).
CONCLUSIONS: A 4-fold or greater decrease in TPPA titers may indicate effective treatment in primary syphilis. Combining TPPA titers with RPR titers results may potentially aid in the early diagnosis of syphilis.
摘要：
背景：在大多数临床环境中，梅毒螺旋体颗粒凝集（TPPA）试验以其与快速血浆反应素（RPR）试验相比具有更高的特异性而闻名，通常用于梅毒的诊断，但是它们在梅毒治疗后用于血清学监测是有争议的。
目的：我们旨在评估TPPA滴度是否适合监测梅毒治疗效果。
方法：首先，纳入232例原发性梅毒患者。在基线（初次就诊）和苄星青霉素G（BPG）治疗后6个月（±1个月）进行血清学测试。第二,新西兰白色雄性兔子感染了梅毒螺旋体（T。pallidum）评估BPG治疗后TPPA滴度的变化。最后,我们比较了在有或没有BPG的情况下，梅毒T.pallidum刺激的兔脾细胞的培养上清液中的TPPA滴度。
结果：治疗6个月后，232例原发性梅毒患者中有150例（64.7%）获得血清学治愈，82例(35.3%)出现不良结局.在110例TPPA滴度下降超过四倍的患者中，其中109例为血清学治愈患者（RPR滴度下降≥4倍）（P＜0.0001）。在梅毒兔模型中，TPPA滴度在治疗亚组显著降低(P=0.016),在非治疗亚组保持恒定(±2倍)或升高(≥4倍).此外,梅毒T.pallidum导致脾细胞培养上清液中TPPA滴度呈阳性（中位数滴度为1:80），BPG可以直接降低培养上清液中的TPPA滴度（中位数滴度为1：40）（P=0.032）。
结论：TPPA滴度下降4倍或更多可能表明原发性梅毒治疗有效。将TPPA滴度与RPR滴度结果相结合可能有助于梅毒的早期诊断。
目的：我们旨在评估TPPA滴度是否适合监测梅毒治疗效果。
方法：首先，纳入232例原发性梅毒患者。在基线（初次就诊）和苄星青霉素G（BPG）治疗后6个月（±1个月）进行血清学测试。第二,新西兰白色雄性兔子感染了梅毒螺旋体（T。pallidum）评估BPG治疗后TPPA滴度的变化。最后,我们比较了在有或没有BPG的情况下，梅毒T.pallidum刺激的兔脾细胞的培养上清液中的TPPA滴度。
结果：治疗6个月后，232例原发性梅毒患者中有150例（64.7%）获得血清学治愈，82例(35.3%)出现不良结局.在110例TPPA滴度下降超过四倍的患者中，其中109例为血清学治愈患者（RPR滴度下降≥4倍）（P＜0.0001）。在梅毒兔模型中，TPPA滴度在治疗亚组显著降低(P=0.016),在非治疗亚组保持恒定(±2倍)或升高(≥4倍).此外,梅毒T.pallidum导致脾细胞培养上清液中TPPA滴度呈阳性（中位数滴度为1:80），BPG可以直接降低培养上清液中的TPPA滴度（中位数滴度为1：40）（P=0.032）。
结论：TPPA滴度下降4倍或更多可能表明原发性梅毒治疗有效。将TPPA滴度与RPR滴度结果相结合可能有助于梅毒的早期诊断。
