Type 1, Type 17 and other pro-inflammatory cytokines are known to play an important role in resistance to pulmonary tuberculosis. The role of these cytokines in tuberculous lymphadenitis (TBL) is not well characterized.

TBL is therefore, characterized by reduced systemic and antigen-specific concentrations of IL-1β and IL-18, which are reversible following anti-TB treatment, indicating that these cytokines are potential correlates of protective immunity in TBL.

To estimate the systemic and mycobacterial antigen - stimulated cytokine concentrations of Type 1, Type 17, other pro-inflammatory and regulatory cytokines in TBL, we examined both the systemic and the antigen-specific concentrations of these cytokines in TBL (n=31) before and after chemotherapy, and compared them with those with latent tuberculosis infection (LTB, n=31).

We observed significantly reduced systemic concentrations of the pro-inflammatory cytokines - IL-1β and IL-18 but not other Type 1 or Type 17 cytokines in TBL compared to LTB. Following standard anti-tuberculosis (TB) treatment, we observed a significant increase in the concentrations of both IL-1β and IL-18. In addition, we also observed significantly reduced baseline or mycobacterial - antigen or mitogen stimulated concentrations of IL-1β and IL-18 in TBL individuals. Similar to systemic cytokine concentrations, anti-TB treatment resulted in significantly increased concentrations of these cytokines following antigen stimulation. Conclusions: TBL is therefore, characterized by reduced systemic and antigen-specific concentrations of IL-1β and IL-18, which are reversible following anti-TB treatment, indicating that these cytokines are potential correlates of protective immunity in TBL.