Background The role of serologic testing for SARS-CoV-2 has evolved during the pandemic as seroprevalence in global populations has increased. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the coronavirus disease 2019 (COVID-19) serology literature and construct updated best practice guidance related to SARS-CoV-2 serologic testing. This guideline is an update to the fourth in a series of rapid, frequently updated COVID-19 guidelines developed by IDSA. Objective To develop evidence-based recommendations and identify unmet research needs pertaining to the use of anti-SARS-CoV-2 antibody tests for diagnosis, decisions related to vaccination and administration of monoclonal antibodies or convalescent plasma in immunocompromised patients, and identification of a serologic correlate of immunity. Methods A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists and experts in systematic literature reviewed, identified, and prioritized clinical questions related to the use of SARS-CoV-2 serologic tests. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. Results The panel recommends against serologic testing to diagnose SARS-CoV-2 infection in the first two weeks after symptom onset (strong recommendations, low certainty of evidence). Serologic testing should not be used to provide evidence of COVID-19 in symptomatic patients with a high clinical suspicion and repeatedly negative nucleic acid amplification test results (strong recommendation, very low certainty of evidence). Serologic testing may assist with the diagnosis of multisystem inflammatory syndrome in children (strong recommendation, very low certainty of evidence). To seek evidence for prior SARS-CoV-2 infection, the panel suggests testing for IgG, IgG/IgM, or total antibodies to nucleocapsid protein three to five weeks after symptom onset (conditional recommendation, low certainty of evidence). In individuals with previous SARS-CoV-2 infection or vaccination, we suggest against routine serologic testing given no demonstrated benefit to improving patient outcomes (conditional recommendation, very low certainty of evidence.) The panel acknowledges further that a negative spike antibody test may be a useful metric to identify immunocompromised patients who are candidates for immune therapy. Conclusions The high seroprevalence of antibodies against SARS-CoV-2 worldwide limits the utility of detecting anti-SARS CoV-2 antibody. The certainty of available evidence supporting the use of serology for diagnosis was graded as very low to low. Future studies should use serologic assays calibrated to a common reference standard.

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美国传染病学会 COVID-19 诊断指南：血清学检测

背景 随着全球人群血清阳性率的增加，SARS-CoV-2 血清学检测的作用在大流行期间发生了变化。美国传染病学会 (IDSA) 召集了一个专家小组，对 2019 年冠状病毒病 (COVID-19) 血清学文献进行系统审查，并构建与 SARS-CoV-2 血清学检测相关的最新最佳实践指南。本指南是 IDSA 制定的一系列快速、频繁更新的 COVID-19 指南中第四个指南的更新。目的 制定基于证据的建议并确定未满足的研究需求，涉及使用抗 SARS-CoV-2 抗体检测进行诊断、与免疫功能低下患者接种疫苗和施用单克隆抗体或恢复期血浆相关的决策以及血清学鉴定免疫力的相关性。方法 由传染病临床医生、临床微生物学家和系统文献专家组成的多学科小组对与 SARS-CoV-2 血清学检测的使用相关的临床问题进行了审查、确定和优先排序。使用建议评估、制定和评价分级（GRADE）方法来评估证据的确定性并提出测试建议。结果 专家组建议不要在症状出现后的前两周内进行血清学检测来诊断 SARS-CoV-2 感染（强烈建议，证据质量低）。对于临床高度怀疑且核酸扩增检测结果反复呈阴性的有症状患者，不应使用血清学检测来提供 COVID-19 的证据（强烈推荐，证据质量极低）。血清学检测可能有助于儿童多系统炎症综合征的诊断（强烈推荐，证据质量非常低）。为了寻找既往 SARS-CoV-2 感染的证据，专家组建议在症状出现三到五周后检测 IgG、IgG/IgM 或核衣壳蛋白总抗体（有条件推荐，证据质量低）。对于既往感染过 SARS-CoV-2 或接种过疫苗的个体，我们建议不要进行常规血清学检测，因为没有证据表明对改善患者预后有益处（有条件推荐，证据质量非常低）。专家组进一步承认，阴性尖峰抗体检测可能会影响患者的预后。一个有用的指标来识别适合免疫治疗的免疫功能低下患者。结论 全球范围内抗 SARS-CoV-2 抗体的高血清阳性率限制了检测抗 SARS-CoV-2 抗体的效用。支持使用血清学诊断的现有证据的确定性被评为非常低到低。未来的研究应使用根据通用参考标准校准的血清学检测方法。