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J Infect Chemother
. 2024 Aug 27:S1341-321X(24)00236-8.
doi: 10.1016/j.jiac.2024.08.019. Online ahead of print. Pre-clinical and clinical evaluation of a surface plasmon field-enhanced fluorescence spectroscopy (SPFS) antigen test for detecting SARS-CoV-2
Nobuyuki Ashizawa 1 , Takahiro Takazono 2 , Kenji Ota 3 , Yuya Ito 4 , Tatsuro Hirayama 5 , Kazuaki Takeda 4 , Shotaro Ide 6 , Naoki Iwanaga 4 , Ayumi Fujita 7 , Masato Tashiro 8 , Naoki Hosogaya 9 , Norihiko Akamatsu 3 , Kosuke Kosai 3 , Takeshi Tanaka 7 , Hironori Kobayashi 10 , Ryosuke Yamauchi 10 , Chie Segawa 10 , Hikaru Koizumi 10 , Natsumi Taka 10 , Haretsugu Hishigaki 10 , Kazuko Yamamoto 11 , Koichi Izumikawa 8 , Katsunori Yanagihara 3 , Hiroshi Mukae 4
Affiliations
Introduction: The diagnostic tools of nucleic acid amplification tests and antigen tests have been extensively employed for the detection of Coronavirus disease 2019 (COVID-19). Although the reverse-transcriptase polymerase chain reaction (RT)-PCR test has high sensitivity and specificity, it is a time-consuming and labor-intensive process. On the other hand, antigen tests are simple and prompt, however, their low sensitivity and potential for false positives have been identified as limitations. In light of these factors, the development of novel tests that combine speed and clinical dependability is a promising prospect.
Methods: Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) excites chromophores by means of an enhanced electromagnetic field induced on a gold film surface. It enables the highly sensitive measurement of biomarkers in a short and simple 20-min window. In this study, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) SPFS-based antigen test targeting the SARS-CoV-2 nucleocapsid protein was performed and evaluated in 25 patients with COVID-19 and 10 non-infected controls.
Results: A positive correlation was observed between antigen levels determined by SPFS and RNA levels determined via RT-PCR. The sensitivity values were 100 %, 92 %, and 62.5 %; and the specificity values were 100 %, 90 %, and 100 %; for nasopharyngeal swabs, nasal swabs, and saliva specimens when the cutoff values were set to 65.1, 0.2, and 1.5 pg/mL, respectively. No clinically problematic cross-reactivity with analogous coronaviruses was observed.
Conclusions: The SARS-CoV-2 SPFS antigen test showed excellent clinical diagnostic accuracy for nasopharyngeal and nasal swabs, with a rapid turnaround.
Keywords: COVID-19; Diagnostic accuracy; PCR; Rapidity; SPFS.
. 2024 Aug 27:S1341-321X(24)00236-8.
doi: 10.1016/j.jiac.2024.08.019. Online ahead of print. Pre-clinical and clinical evaluation of a surface plasmon field-enhanced fluorescence spectroscopy (SPFS) antigen test for detecting SARS-CoV-2
Nobuyuki Ashizawa 1 , Takahiro Takazono 2 , Kenji Ota 3 , Yuya Ito 4 , Tatsuro Hirayama 5 , Kazuaki Takeda 4 , Shotaro Ide 6 , Naoki Iwanaga 4 , Ayumi Fujita 7 , Masato Tashiro 8 , Naoki Hosogaya 9 , Norihiko Akamatsu 3 , Kosuke Kosai 3 , Takeshi Tanaka 7 , Hironori Kobayashi 10 , Ryosuke Yamauchi 10 , Chie Segawa 10 , Hikaru Koizumi 10 , Natsumi Taka 10 , Haretsugu Hishigaki 10 , Kazuko Yamamoto 11 , Koichi Izumikawa 8 , Katsunori Yanagihara 3 , Hiroshi Mukae 4
Affiliations
- PMID: 39197666
- DOI: 10.1016/j.jiac.2024.08.019
Introduction: The diagnostic tools of nucleic acid amplification tests and antigen tests have been extensively employed for the detection of Coronavirus disease 2019 (COVID-19). Although the reverse-transcriptase polymerase chain reaction (RT)-PCR test has high sensitivity and specificity, it is a time-consuming and labor-intensive process. On the other hand, antigen tests are simple and prompt, however, their low sensitivity and potential for false positives have been identified as limitations. In light of these factors, the development of novel tests that combine speed and clinical dependability is a promising prospect.
Methods: Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) excites chromophores by means of an enhanced electromagnetic field induced on a gold film surface. It enables the highly sensitive measurement of biomarkers in a short and simple 20-min window. In this study, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) SPFS-based antigen test targeting the SARS-CoV-2 nucleocapsid protein was performed and evaluated in 25 patients with COVID-19 and 10 non-infected controls.
Results: A positive correlation was observed between antigen levels determined by SPFS and RNA levels determined via RT-PCR. The sensitivity values were 100 %, 92 %, and 62.5 %; and the specificity values were 100 %, 90 %, and 100 %; for nasopharyngeal swabs, nasal swabs, and saliva specimens when the cutoff values were set to 65.1, 0.2, and 1.5 pg/mL, respectively. No clinically problematic cross-reactivity with analogous coronaviruses was observed.
Conclusions: The SARS-CoV-2 SPFS antigen test showed excellent clinical diagnostic accuracy for nasopharyngeal and nasal swabs, with a rapid turnaround.
Keywords: COVID-19; Diagnostic accuracy; PCR; Rapidity; SPFS.