Correlation of serum and urine ferritin levels with inflammatory cytokine levels. Serum and urine ferritin levels determined using ELISA were correlated with inflammatory cytokine levels. Urine ferritin levels correlated with urine IL-6 (r = 0.68, P < 0.001) and serum IL-6 (r = 0.56, P < 0.0001).
Vanarsa et al. Arthritis Research & Therapy 2012 14:R182 doi:10.1186/ar4012