Abstract：
Long COVID (LC) is characterized by persistent symptoms following SARS-CoV-2 infection, with various mechanisms offered to explain its pathogenesis. This study explored whether adaptive humoral anti-SARS-CoV-2 responses differ in LC. Unvaccinated COVID-19 convalescents (n = 200) were enrolled, with 21.5% (n = 43) presenting LC three months post-infection. LC diagnosis was based on persistent symptom(s) and alterations in biochemical/clinical markers; three phenotypes were distinguished: cardiological, pulmonary, and psychiatric LC. All three phenotypes were characterized by significantly decreased seroprevalence of IgG antibodies against nucleocapsid (anti-NP). LC was associated with decreased odds of testing positive for anti-NP (OR = 0.35, 95%CI: 0.16-0.78, p = 0.001). Seropositive LC patients had lower anti-S1 and anti-S2 levels than individuals without LC, and those with pulmonary and psychological phenotypes also revealed decreased anti-RBD concentrations. The results indicate that LC can be characterized by diminished humoral response to SARS-CoV-2. The potential implication of this phenomenon in post-acute viral sequelae is discussed.
摘要：
长COVID（LC）的特征是SARS-CoV-2感染后持续的症状，提供了各种机制来解释其发病机理。这项研究探讨了LC中适应性体液抗SARS-CoV-2反应是否不同。未接种疫苗的COVID-19疗养者（n=200）被纳入，21.5%(n=43)在感染后三个月出现LC。LC诊断基于持续症状和生化/临床标志物的改变；区分三种表型：心脏病，肺,精神病学LC。所有三种表型的特征在于抗核衣壳IgG抗体（抗NP）的血清阳性率显着降低。LC与抗NP检测阳性几率降低相关(OR=0.35,95CI:0.16-0.78,p=0.001)。血清阳性LC患者的抗S1和抗S2水平低于无LC患者，具有肺和心理表型的患者也显示出抗RBD浓度降低。结果表明，LC的特征在于对SARS-CoV-2的体液反应减弱。讨论了这种现象在急性病毒后遗症中的潜在含义。
