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：本研究对比了实测的血清新型冠状病毒（SARS-CoV-2）抗体水平与通过唾液、鼻腔样本预测得到的血清抗体水平。通过唾液样本（图A）与鼻腔样本（图B）预测的血清新冠抗体水平，首先将唾液/鼻腔样本的总免疫球蛋白G（IgG）含量进行归一化处理，再基于配对血清样本中实测的血清总IgG浓度对上述数值进行校正后得到。每张图表均标注了决定系数R²，所有组别均满足双侧检验p<0.0001（唾液-血清配对样本n=64，鼻腔-血清配对样本n=55），绘图软件为GraphPad Prism。坐标轴采用对数刻度。补充表1：唾液中新冠病毒S1特异性抗体归一化至总IgG并预测血清抗体水平的示例。第一列为3份捐赠唾液样本的新冠病毒S1特异性抗体酶联免疫吸附试验（ELISA）检测结果，数值以BAU/ml为单位表示。第二列为上述唾液样本中测得的总IgG水平，单位为ug/ml IgG。第三列为将新冠病毒S1特异性抗体水平除以对应唾液样本中的总IgG后得到的数值，即每微克总IgG对应的特异性抗体含量（单位为BAU/ug）。为从唾液检测结果预测血清抗体水平，本研究使用所有血清捐赠样本的平均总IgG浓度（第四列，单位为ug/ml）乘以唾液样本中的新冠病毒S1特异性抗体/总IgG比值（第三列）。通过该计算得到的预测值（第五列）可与配对血清样本中的实测值（第六列）进行对比。