IFNa-IgG ELISA results from P 1 and P 3. Plasma samples from P1 and P3 in the Danish cohort were evaluated for the presence of anti-IFN-α IgG autoAbs by ELISA. Absorbance values are shown for each patient, alongside representative positive and negative control samples. The dotted line indicates the assay cut-off for positivity. Positive control (red), negative control (grey), and patient samples (black) are plotted as means with ranges.