Background: In peripheral nerve damage˒ pro-inflammatory cytokines, such as tumour necrosis factor-alpha (TNF- α) are rapidly recruited mediating many of the deleterious events associated with Wallerian degeneration.
Aim of the work: Identify the short and long-term effects of TNF- α inhibitor on the nerve regeneration after experimental sciatic nerve transection. Material and methods: 36 adult male albino rats were divided into 3 groups, 12 rats each. Group A (control) was subdivided into 2 subgroups (A1 & A2). A1 left without any intervention and A2 (sham), half of each subgroup were sacrificed after 1 and 8 weeks. Group B (untreated) was subdivided into 2 subgroups (B1 & B2), sciatic nerve transection was done, B1 was sacrificed after 1 week and B2 after 8 weeks. Group C (treated) was subdivided into two subgroups (C1 & C2), sciatic nerve transection and immediate intraperitoneal injection with anti-TNF- α (Enbrel 25 mg) vial 6 mg/kg single dose was done. C1 was sacrificed after 1 week and C2 after 8 weeks. Nerve endings for all groups were processed for light, transmission electron microscope, immunohistochemical (ED1 cell and S100 antigen), morphometric and statistical studies. Results: 1 week after injury macrophage cells (MC) invasion and excessive demyelination occurred, anti- TNF- α reduced the MC invasion. 8 weeks after the injury regenerating myelinated axons were observed. Number of the regenerating axons showed statistically significant increase in the treated group compared to the injured group.
Conclusion: Immediate administration of TNF- α antagonist after induced sciatic nerve injury enhanced nerve regeneration.