IL6 and myalgic encephalomeyelitis/chronic fatigue syndrome: On the other hand, serum and CSF IL-6 levels were significantly higher in patients with CFS compared to the SFS group (55.8 ± 13.7vs 31.9 ± 7.6 ng/ml for serum IL-6 and 39.06 ± 5.7 vs 22.3 ± 6.8 ng/ml for CSF IL-6, respectively; P < 0.01) Table 2.