Knuutila Aapo, Barkoff Alex-Mikael, Mertsola Jussi, Osicka Radim, Sebo Peter, He Qiushui
Institute of Biomedicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland.
Department of Pediatrics and Adolescent Medicine, Turku University Hospital, Kiinamyllynkatu 4-8, 20520 Turku, Finland.
Diagnostics (Basel). 2021 Jan 27;11(2):180. doi: 10.3390/diagnostics11020180.
Serological diagnosis of pertussis is mainly based on anti-pertussis toxin (PT) IgG antibodies. Since PT is included in all acellular vaccines (ACV), serological assays do not differentiate antibodies induced by ACVs and infection. Adenylate cyclase toxin (ACT) is not included in the ACVs, which makes it a promising candidate for pertussis serology with the specific aim of separating infection- and ACV-induced antibodies. A multiplex lateral flow test with PT and ACT antigens was developed to measure serum antibodies from pertussis-seropositive patients ( = 46), healthy controls ( = 102), and subjects who received a booster dose of ACV containing PT, filamentous hemagglutinin, and pertactin ( = 67) with paired sera collected before and one month after the vaccination. If the diagnosis was solely based on anti-PT antibodies, 98.5-44.8% specificity (before and after vaccination, respectively) and 78.2% sensitivity were achieved, whereas if ACT was used in combination with PT, the sensitivity of the assay increased to 91.3% without compromising specificity. No increase in the level of anti-ACT antibodies was found after vaccination. This exploratory study indicates that the use of ACT for serology would be beneficial in combination with a lower quantitative cutoff for anti-PT antibodies, and particularly in children and adolescents who frequently receive booster vaccinations.
百日咳的血清学诊断主要基于抗百日咳毒素（PT）IgG抗体。由于PT包含在所有无细胞疫苗（ACV）中，血清学检测无法区分由ACV诱导产生的抗体和感染诱导产生的抗体。腺苷酸环化酶毒素（ACT）不包含在ACV中，这使其成为百日咳血清学检测的一个有前景的候选指标，其具体目的是区分感染诱导和ACV诱导的抗体。开发了一种同时检测PT和ACT抗原的多重侧向流动试验，以检测百日咳血清阳性患者（n = 46）、健康对照者（n = 102）以及接受含PT、丝状血凝素和百日咳杆菌黏附素的ACV加强剂量疫苗接种的受试者（n = 67）在接种前和接种后1个月采集的配对血清中的抗体。如果仅基于抗PT抗体进行诊断，特异性分别为98.5%（接种前）和44.8%（接种后），敏感性为78.2%，而如果将ACT与PT联合使用，检测的敏感性提高到91.3%，且不影响特异性。接种疫苗后未发现抗ACT抗体水平升高。这项探索性研究表明，将ACT用于血清学检测并结合较低的抗PT抗体定量临界值将是有益的，特别是对于经常接受加强疫苗接种的儿童和青少年。
