IGHA1 and systemic lupus erythematosus: Interestingly, when we compared the diagnostic robustness of salivary SIgA concentrations through their displayed AUC or sensitivity at 95% of specificity values with those from anti-dsDNA, anti-nucleosome, and complement levels in independent SLE cohorts reported previously (31, 32) as seen in Supplementary Table 1, these sensitivity/specificity values from SIgA are very similar to those displayed by traditional biomarkers, being IgA1 concentration the more robust.