Table 2.

Inflammatory cytokines that regulate LDH

Inflammatory cytokines	Sample	Results	Reference
IL-6, IL-8, TNF-α, IL-4, IL-10	Patient serum	Sciatica is accompanied by an imbalance in the expression levels of inflammatory cytokines.	Wang et al. 2016 [78]
TNF-α, IL-4	Patient serum	The degree of pain is negatively correlated with the level of the anti-inflammatory cytokine IL-4.	Zu et al. 2016 [79]
IL-6, IL-8	Patient serum	IL-6 and IL-8 levels are elevated.	Pedersen et al. 2015 [80]
IL-6, COX-2, MMP-1, MMP-3	Human IVD	IL-1β upregulates the expression levels of IL-6, COX-2, MMP-1, and MMP-3.	Jimbo et al. 2005 [81]
TGF-β1, IGF-1, IL-6, IL-6R	Human IVD	The herniated IVD produces factors such as TGF-β1, IGF-1, IL-6, IL-6R, and fibronectin.	Specchia et al. 2002 [82]
IL-1α, IL-1β, IL-6, TNF-α	Human IVD	The herniated IVD produces inflammatory cytokines such as IL-1α, which in turn increase PGE2 production.	Takahashi et al. 1996 [83]
TNF-α, IL-6, IL-8, PGE2	Co-culture system of IVD and macrophages	TNF-α induces the production of IL-6 and PGE2, not IL-8.	Takada et al. 2012 [77]
IL-6	Co-culture system of IVD and macrophages	The infiltration of macrophages into the herniated disc may be a trigger for IL-6 production and related neurological symptoms.	Takada et al. 2004 [84]

Abbreviations: COX-2 cyclooxygenase-2, PGE2 prostaglandin E2, TGF-β1 transforming growth factor beta-1, IGF-1 insulin-like growth factor-1, IL-6R interleukin 6 receptor