IL18 and juvenile idiopathic arthritis: In the other JIA subgroups, mean IL-18 levels in patients with and without the S01/S01 diplotype configuration were 572 ± 327 pg/ml versus 325 ± 302 pg/ml in those with polyarthritis, and 252 ± 124 pg/ml versus 219 ± 48 pg/ml in those with oligoarthritis.