TNF and Sciatica: In sciatica patients, several longitudinal studies reported moderate positive correlations for serum (r  =  0.629) and biopsy (r  =  0.65) TNF-α with pain level; severe pain (VAS > 4) was also shown to be significantly associated with increased high-sensitivity CRP levels (adjusted OR  =  3.4 (95% CI, 1.1 to 10) [48].