IL6 and polyarteritis nodosa: IL-6 was increased in PAN [18.88 pg/ml (0–18.71 pg/ml); P = 0.0007] and RAS [6.820 pg/ml (0–371.1 pg/ml); P = 0.016] versus the control [1.14 pg/ml (0–8.4 pg/ml)].