(A) Levels of IFNα/β were measured in plasma samples from HIV-1 uninfected control (HIVneg; n=14) and untreated, chronic HIV-1 infected (HIV-1+; n=24) study participants. (B) IFNα/β gene transcript levels were measured in PBMC from HIV-1 uninfected (HIVneg; n=14) and untreated, chronic HIV-1 infected (HIV-1+; n=24) study participants. (C, D) Expression of IFNα subtypes (number of transcripts for each IFNα subtype relative to total IFNα gene transcripts) in PBMC were assessed in 13 HIV-infected and 8 uninfected study participants. Lines represent median values (A, B, D) or are shown as median (range) (D). *Bold font indicates a significant p value. Italics indicates a trend (P<0.1). Statistical analysis was performed using the Mann-Whitney test to determine differences between unmatched groups.