Characterization of AAN-I-IFN in the patient. (A) AIR cells were stimulated with the 12 subtypes of IFN-α at a concentration of 1 ng/ml, with or without blood from the patient (pt), an AAN-I-IFN–positive control (positive ctrl), an APS-1 patient, or healthy donors (HD). All samples were diluted 1:20. Renilla luciferase activity was measured 24 h after stimulation and expressed as a percentage of the mean value for HDs. Luciferase activity levels <25% of HD values were considered to indicate neutralizing activity. Three separate blood draws from the patient were sampled. Experiment was done once. (B) Multiplex assay beads were incubated with blood samples, and MFI values were normalized against the beads-only control. Normalized MFI values > 3 were considered positive. Two separate blood draws from the patient were sampled. Experiment was done once. AIR, A549-IFN-reporter.