Department of Cardiology, Copenhagen University Hospitalgrid.4973.9, Herlev and Gentofte, Denmark.
Department of Emergency Medicine, Copenhagen University Hospitalgrid.4973.9, Herlev and Gentofte, Denmark.
Microbiol Spectr. 2022 Dec 21;10(6):e0253722. doi: 10.1128/spectrum.02537-22. Epub 2022 Nov 9.
The majority of long coronavirus disease (COVID) symptoms are not specific to COVID-19 and could be explained by other conditions. The present study aimed to explore whether Danish individuals with a perception that they suffer from long COVID have antibodies against the nucleocapsid antigen, as a proxy for detecting previous infection. The study was conducted in February and March 2021, right after the second surge of the COVID-19 pandemic in Denmark. All members of the social media group on Facebook "Covidramte med senfølger" ("long COVID sufferers'') above the age of 17 years and living in Denmark were invited to participate in a short electronic questionnaire about long COVID risk factors and symptoms. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid (N) protein was detected in blood samples as a proxy for natural SARS-CoV-2 infection. The final study population comprised 341 participants (90.6% females) who completed blood sampling and answered the questionnaire. A total of 232 (68%) were seropositive (median age, 49.5 years; interquartile range [IQR], 41 to 55 years; 90.1% females). There was no significant difference between sexes and serostatus. Seronegative and seropositive individuals had a similar burden of symptoms that could be attributed to long COVID. Time since perceived COVID-19 was significantly longer in the group of seronegative individuals than the seropositive ones ( < 0.001). This study suggests that long-COVID sufferers are mostly women and showed that a third of the participants did not have detectable anti-N-protein antibodies. It emphasizes the importance of early confirmation of COVID-19, as this study indicates an overlap between long-COVID symptoms and symptoms that are possibly of another origin. This cohort study included questionnaire data as well as anti-nucleocapsid antibody analysis, allowing us to determine whether participants were seropositive due to vaccination or natural infection. The study emphasizes the importance of early confirmation of COVID-19, as antibodies recede with time, and it indicates an overlap between long COVID symptoms and symptoms possibly of another origin.
大多数长新冠疾病（COVID）症状并非 COVID-19 所特有，可能由其他疾病引起。本研究旨在探讨丹麦自我感知患有长新冠疾病的个体是否存在针对核衣壳抗原的抗体，以此作为检测既往感染的替代指标。该研究于 2021 年 2 月至 3 月在丹麦 COVID-19 第二波疫情过后进行。邀请了脸书社交群组“Covidramte med senfølger”（“长新冠疾病患者”）中年龄超过 17 岁且居住在丹麦的所有成员参加一项关于长新冠疾病风险因素和症状的简短电子问卷调查。使用严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）核衣壳（N）蛋白检测血液样本中的抗体，作为自然 SARS-CoV-2 感染的替代指标。最终研究人群包括 341 名完成采血和问卷调查的参与者（90.6%为女性）。共有 232 名（68%）血清阳性（中位年龄 49.5 岁；四分位距 [IQR] 41 至 55 岁；90.1%为女性）。血清阳性和阴性个体在性别和血清学状态方面无显著差异。血清阴性和阳性个体的长新冠疾病相关症状负担相似。自我感知 COVID-19 时间与血清阴性个体相比，血清阳性个体显著更长（<0.001）。本研究表明，长新冠疾病患者大多为女性，并表明三分之一的参与者无法检测到抗 N 蛋白抗体。本研究强调了早期确认 COVID-19 的重要性，因为本研究表明长新冠疾病症状与可能由其他来源引起的症状之间存在重叠。本队列研究纳入了问卷调查数据和抗核衣壳抗体分析，使我们能够确定参与者的血清阳性是由于疫苗接种还是自然感染所致。本研究强调了早期确认 COVID-19 的重要性，因为抗体随时间消退，并表明长新冠疾病症状与可能由其他来源引起的症状之间存在重叠。
