Degenerative disc disease in young adults: cytokine profile and angiogenic factors

Back pain (BP), associated with the degenerative disc disease (DDD), poses a heavy social and economic burden due to early disability and indications to surgery, emerging in young adults. Pathophysiological basis of premature intervertebral disc (IVD) degeneration is being actively studied. The study was aimed to define the profiles of inflammatory cytokines in DDD, as well as their relationship to the structural spine diseases. The molecular genetic analysis of the mRNA gene abundance in patients with BP and herniated IVD after discectomy and healthy individuals was performed by the quantitative polymerase chain reaction method. High expression of TNF alpha, IL17 was revealed in the IVD tissues of the affected patients (p < 0.01); the levels of TNF alpha and IL1 beta correlated with the DDD severity (r = 0.301 and 0.37; p < 0.05). Elevated expression of IL1 beta, IL6 was found in peripheral white blood cells (p < 0.01); the levels of IL6 negatively correlated with Modic type 1 and 2 changes (r = -0.31; p < 0.05), and the levels of IL17 positively correlated with the IVD herniation in combination with erosions of the adjacent vertebral body endplates and Modic changes (r = 0.401; p < 0.05). The expression of VEGF-A in the IVD tissues and white blood cells negatively correlated with the DDD grades (r = -0.85; p < 0.001), indicating reduced vascularization in the terminal phase of the disease. The findings on DDD demonstrate the contribution of the local low-immune inflammation, coupled with the intense disc vascularization at the earlier stages, and associated with the reactive inflammation in vertebral bodies. The results are prerequisites for developing the anti-inflammatory and reparative therapy based on the DDD grade and the presence of Modic changes in young adults with BP.