Enrichment in auto-Ab–positive cases among patients with critical influenza pneumonia. (A) Prevalence of auto-Ab–positive cases among patients with critical influenza (n = 279, red bars) and in the general population (n = 34,159, black bars). *, P < 0.05; ****, P < 10−5. (B) OR for the presence of auto-Abs, by sex and age, relative to the general population, with adjustment of the comparison by means of Firth’s bias-corrected logistic regression. The horizontal bars indicate the upper and lower limits of the 95% CIs. α + ω, auto-Abs neutralizing both IFN-α2 and IFN-ω; α ± ω, auto-Abs neutralizing IFN-α2 with or without IFN-ω; α, auto-Abs neutralizing IFN-α2 only; *, P < 0.05; **, P < 10−2; ***, P < 10−3; ****, P < 10−4.