Potential False-Negative Nucleic Acid Testing Results for Severe Acute Respiratory Syndrome Coronavirus 2 from Thermal Inactivation of Samples with Low Viral Loads
Potential False-Negative Nucleic Acid Testing Results for Severe Acute Respiratory Syndrome Coronavirus 2 from Thermal Inactivation of Samples with Low Viral Loads
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DOI：
10.1093/clinchem/hvaa091
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发表时间：
2020-06-01
影响因子：
9.3
通讯作者：
Ren, Simei
中科院分区：
文献类型：
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作者：
Pan, Yang;Long, Luyao;Ren, Simei
背景：2019年冠状病毒病（COVI D-19）自2019年底以来在全球广泛传播。核酸检测在COVID-19患者诊断和管理中发挥了重要作用。在某些情况下，建议在NAT前采用56℃的热灭活方法灭活严重急性呼吸综合征冠状病毒2 （SARS-CoV-2）。然而，这种方法理论上可能会破坏这种单链RNA病毒的核酸完整性，并在实时聚合酶链反应（RT-PCR）测试中导致假阴性。方法：我们研究了热失活是否会影响病毒NAT的结果。我们检查了热失活对SARS-CoV-2定量RT-PCR结果的影响，特别是对携带低病毒载量标本的假阴性结果的影响。我们还研究了不同标本类型、标本保存时间和化学灭活方法对nat的影响。结果：我们的研究显示，在热培养后的RT-PCR检测中，诊断为COVID-19的患者标本的Ct值升高。此外，大约一半的弱阳性样本（15个样本中的7个，46.7%）在至少一次平行测试中热失活后呈RT-PCR阴性。使用胍基裂解法保存这些标本对RT-PCR结果的影响较小，假阴性较少（15个样品中有2个，13.3%），Ct值的增加也明显低于热失活。结论：热失活对RT-PCR检测SARS-CoV-2的效率有不利影响。鉴于化学灭活剂的适用性有限，需要考虑其他方法来确保对实验室人员的全面保护。
BACKGROUND: Coronavirus disease-2019 (COVI D-19) has spread widely throughout the world since the end of 2019. Nucleic acid testing (NAT) has played an important role in patient diagnosis and management of COVID-19. In some circumstances, thermal inactivation at 56 degrees C has been recommended to inactivate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) before NAT. However, this procedure could theoretically disrupt nucleic acid integrity of this single-stranded RNA virus and cause false negatives in real-time polymerase chain reaction (RT-PCR) tests.METHODS: We investigated whether thermal inactivation could affect the results of viral NAT. We examined the effects of thermal inactivation on the quantitative RT-PCR results of SARS-CoV-2, particularly with regard to the rates of false-negative results for specimens carrying low viral loads. We additionally investigated the effects of different specimen types, sample preservation times, and a chemical inactivation approach on NAT.RESULTS: Our study showed increased Ct values in specimens from diagnosed COVID-19 patients in RT-PCR tests after thermal incubation. Moreover, about half of the weak-positive samples (7 of 15 samples, 46.7%) were RT-PCR negative after heat inactivation in at least one parallel testing. The use of guanidinium-based lysis for preservation of these specimens had a smaller impact on RT-PCR results with fewer false negatives (2 of 15 samples, 13.3%) and significantly less increase in Ct values than heat inactivation.CONCLUSION: Thermal inactivation adversely affected the efficiency of RT-PCR for SARS-CoV-2 detection. Given the limited applicability associated with chemical inactivators, other approaches to ensure the overall protection of laboratory personnel need consideration.