IFNG and rheumatoid arthritis: All HCWs, but one, showed an IFN-γ-S-specific response (48/49, 97.9%), whereas in RA patients a significantly different proportion of responders and a lower quantitative IFN-γ response was observed compared to controls (23/35, 65.7%, p < 0.0001) (Table 2 and Figure 6A).