TLR agonist stimulation caused significant group differences in the release of IL-1β in chronic pain patients and pain-free participants.

Isolated white cells obtained from new chronic pain patients (closed circle) and pain-free controls from previous study (open triangle) were stimulated with a range of (A) Pam3CSK4 (TLR2) concentrations (13 pg·ml−1 to 1 µg·ml−1) and (B) LPS (TLR4) concentrations (6 pg·ml−1 to 10 µg·ml−1) to generate the response curves and resulted in significant group differences (Pam3CSK4; P<0.0001 and LPS, P = 0.004). Error bars on graphs represent standard error of the mean.