IFNG and rheumatoid arthritis: RA patients with BI showed lower median titres of anti-S/RBD-IgG (BAU/mL) [476 (IQR: 51–2020) vs. 1360 (IQR: 642–3469) (p = 0.145)], and a significantly lower median titre of neutralising antibodies [at 20 (IQR: 5–80) vs. 160 (IQR:40–320) (p = 0.005)] than uninfected patients, but similar levels of IFN-γ [at 11 pg/mL (IQR: 1–111) vs. 27 pg/mL (IQR: 4–92) (p = 0.446)] (Supplementary Figure S2).