Detection of auto-Abs neutralizing type I IFNs in the WNVD subgroups of patients from seven new cohorts. (A and B) Luciferase-based neutralization assays for detecting auto-Abs neutralizing 10 ng/ml IFN-α2, IFN-ω, or IFN-β and 100 pg/ml IFN-α2 or IFN-ω, or 1 ng/ml IFN-β in the WNVD group and in the two WNVD subgroups of hospitalized patients with neuroinvasive WNVD (WNND) and without neuroinvasive disease. Neutralizing activity was defined as a luciferase signal below 15%. (C and D) Percentages of individuals with auto-Abs neutralizing type I IFNs at a concentration of 10 ng/ml or 100 pg/ml for IFN-α2 or IFN-ω, or 1 ng/ml for IFN-β in the WNVD group and in the two subgroups of WNVD patients hospitalized with WNND and without neuroinvasive disease. IFN-α, auto-Abs neutralizing IFN-α2 (regardless of their effects on other IFNs); IFN-ω, auto-Abs neutralizing IFN-ω (regardless of their effects on other IFNs); IFN-α ± ω ± β, auto-Abs neutralizing IFN-α2 and/or IFN-ω and/or IFN-β; IFN-α + ω, auto-Abs neutralizing both IFN-α2 and IFN-ω.