Supplementary material: Accurate prediction of serum antibody levels from noninvasive saliva/nasal samples

Supplemental Figure 1. Measured serum Sars-CoV-2 antibody level compared with the level predicted from saliva and nasal samples. The predicted serum covid antibody levels from saliva (A) and nasal (B) were obtained by first normalizing the saliva/nasal samples to their total IgG content, and then correcting these values to the measured total IgG serum concentration derived from the paired serum sample. The Coefficient of determination, R2 is shown on each graph, p (two-tailed) < 0.0001 in each case (n=64 for saliva/serum, n=55 for nasal/serum paired samples) (GraphPad Prism). Axes are log scale.

Supplemental Table 1. Example of normalization of specific Covid S1 antibodies in saliva to total IgG and prediction of serum levels. Column one shows ELISA measurements of Covid S1 specific antibodies in the saliva of 3 donated samples, values are expressed as BAU/ml. The second column is the total IgG level measured in the saliva samples, expressed as ug/ml of IgG. The third column shows the values obtained when the specific Covid S1 antibody level is divided by the total IgG found in the saliva sample, to give the specific antibody measurement per ug of total IgG (units BAU/ug). To predict the serum levels from that detected in saliva, the average total IgG concentration obtained for all serum donations (expressed in ug/ml, in column 4) was used to multiply the specific Covid S1/total IgG in saliva (column 3). The predicted (column 5) obtained from this calculation can be compared to the value measured in the paired serum sample (column 6).

补充图1. 比较血清中测得的Sars-CoV-2抗体水平与唾液和鼻拭子样本预测的水平。唾液（图A）和鼻拭子（图B）预测的血清covid抗体水平，首先通过将唾液/鼻拭子样本标准化至其总IgG含量，然后校正这些值至由配对血清样本获得的测量总IgG血清浓度。每个图表上均显示了决定系数R2，p值（双尾）均小于0.0001（唾液/血清n=64，鼻拭子/血清配对样本n=55）（GraphPad Prism）。坐标轴采用对数尺度。

补充表1. 唾液中特定Covid S1抗体标准化至总IgG及血清水平预测的示例。第一列显示了3个捐赠样本唾液中Covid S1特定抗体的ELISA测量值，数值以BAU/ml表示。第二列是唾液样本中测量的总IgG水平，以ug/ml的IgG表示。第三列显示了当特定Covid S1抗体水平除以唾液样本中发现的总量IgG时得到的值，以每ug总量IgG的特定抗体测量值（单位BAU/ug）表示。为了从唾液中检测到的值预测血清水平，使用了所有血清捐赠样本中获得的总IgG浓度的平均值（以ug/ml表示，见第四列），将其与唾液中的特定Covid S1/总量IgG（第三列）相乘。由此计算得到的预测值（第五列）可以与配对血清样本中测量的值（第六列）进行比较。