Baseline and antigen-stimulated frequencies of monocytes expressing cytokines were determined by flow cytometry in Ss+ (light grey n =15) and Ss− (dark grey n =15) individuals. The (A) baseline (unstimulated) as well as (B) PPD, (C) WCL and (D) P/I stimulated frequencies of monocytes expressing cytokines (IL-1α, IL-1β, TNF-α, IL-6, IL-10 and IL-12) are shown. Each circle represents a single individual and the bars represent the GM values. Net frequencies were calculated by subtracting baseline frequencies from the antigen-induced frequencies for each individual. The p values were calculated using the Mann–Whitney U test.