背景:半定量和定量免疫测定是评估免疫后免疫力的最常用方法。
目的:比较COVID-19患者和免疫健康个体的四种SARS-CoV-2定量血清学检测,癌症患者,和免疫抑制治疗的患者。
方法:使用来自COVID-19和疫苗组的210份血清学样本来创建血清学样本库。来自四个制造商的血清学方法,即Euroimmun,罗氏,雅培,还有DiaSorin,进行了定量评估,半定量,和定性抗体测量。所有四种方法测量抗SARS-CoV-2刺突受体结合结构域的IgG抗体,并以结合抗体单位/ml(BAU/ml)报告结果。选择±25%的总允许误差(TEa)作为标准来确定两种方法在数量上是否临床上等同。使用数字抗体浓度除以每种方法的截止值得到半定量结果(滴度)。
结果:所有配对的定量比较都显示出不可接受的性能。以TEa为±25%,最好的协议是Euroimmun和DiaSorin之间的74个(210个样本中的35.2%),而Euroimmun和Roche之间的最低一致性为11个(210个样本中的5.2%)。所有四种方法中的抗体滴度显著不同(p<0.001)。来自相同样品的最高滴度差异在Roche和DiaSorin之间具有1392倍差异。在定性比较中,配对比较均未显示可接受的比较(p<0.001)。
结论:四个评估的测定之间存在较差的相关性,定量,半定量,和定性。需要进一步协调测定以实现可比的测量。
BACKGROUND: Semi-quantitative and quantitative immunoassays are the most commonly used methodology to evaluate immunity post immunization.
OBJECTIVE: To compare four quantitative SARS-CoV-2 serological assays in COVID-19 patients and immunized healthy individuals, cancer patients, and patients with immunosuppressive therapy.
METHODS: 210 serological samples from COVID-19 infection and vaccination cohorts were used to create a serological sample repository. Serological methods from four manufacturers, namely Euroimmun, Roche, Abbott, and DiaSorin, were evaluated for quantitative, semi-quantitative, and qualitative antibody measurements. All four methods measure IgG antibodies against the SARS-CoV-2 spike receptor-binding domain and report the results in Binding Antibody Unit/mL (BAU/mL). A Total Error Allowable (TEa) of ±25% was chosen as the criteria to determine whether two methods are clinically equivalent quantitatively. Semi-quantitative results (titers) were derived using numeric antibody concentration divided by the cut-off value for each method.
RESULTS: All paired quantitative comparisons demonstrated unacceptable performance. With ±25% as TEa, the best agreement was 74 (35.2% out of 210 samples) between Euroimmun and DiaSorin, whereas the lowest agreement was 11 (5.2% out of 210 samples) between Euroimmun and Roche. Antibody titers amongst all four methods were significantly different (p < 0.001). The highest titer difference from the same sample is between Roche and DiaSorin with a 1392-fold difference. On qualitative comparison, none of the paired comparison showed acceptable comparison (p < 0.001).
CONCLUSIONS: Poor correlation exists between four evaluated assays, quantitatively, semi-quantitatively, and qualitatively. Further harmonization of assays is required to achieve comparable measurements.