**Abstract**

The study reviews findings of the recent experiments designed to investigate cytokine profile after a spinal cord injury. The role of key cytokines was assessed in the formation of cellular response to trauma. The specific immunopathogenic interaction of the nervous and immune systems in the immediate and chronic post-traumatic periods is summarized. The practicality of a step-by-step approach to assessing the cytokine profile in spinal cord injury is shown, the need to take into account the combination of pathogenetic and protective components in the implementation regulatory effects of individual cytokines, their integration into regenerative processes in the damaged spinal cord, which allows a rational approach to the organization of the treatment process and the development of new medicines.

**Keywords:** Spinal cord injury, glial scare, cytokines, cellular response

## **1. Introduction**

Spinal cord injury (SCI) is a significant global public health issue and a common cause of permanent disability in patients [1, 2]. According to the WHO world population estimates, every year up to 500,000 people suffer a spinal cord injury [3], including young adults between the ages of 20 and 35 [4]. The annual incidence rate of traumatic SCI (TSCI) in developed countries is approx. 3 per 100,000 population [5], though these data could be inconsistent with the big picture, since 16%-30% of patients with spinal injuries die before being admitted to the hospital [6, 7]. Thus, functional recovery of the spinal cord with structural damages caused by trauma is recognized as one of the most challenging and socially essential topics of modern regenerative medicine [8].

Mortality from SCI depends mainly on the severity of spinal cord lesion, and at the pre-hospital phase, it reaches 37% [9]. In-hospital mortality rates are affected by the severity of spinal cord damage and the SCI-related early or late complications, as well as the timeliness of specialized health care provision. Mortality rates range between 8 and 58.3% in different medical settings, depending on their capacity [10–12]. High mortality rates (ranging between 16% and 18%) are reported for children. Frequently they are associated with a trauma of the cervical

spine, especially its upper portion [13–16]. The leading causes of death comprise respiratory problems, cardiovascular disorders, thromboembolic events, infectious complications, and suicides [17]. Disability rates after vertebral column and spinal cord injuries vary from 57.5 to 100%, and the data indicate a trend towards an annual increase of people with disabilities after SCI [18].

Prominent underlying SCI causes include road traffic injuries (36–43%), falls from height (24.2–63.2%), shallow water diving (3–32%), sports activities and accidents (22.5%) [19–22], while criminal traumas account for 10-25% of the injuries [23]. The leading causes of injuries vary for different years and across geographic regions [24]. In this context, spinal cord injuries related to ocean waves are commonly reported in the coastal areas, among beachgoers, etc. [25].

Spinal cord injuries resulting from vertebral column trauma are reported for 36–72% of patients [10, 11, 26, 27]. Craniocerebral trauma is more commonly associated with cervical spine fractures (18–72%). Thoracic spine fractures are usually combined with multiple non-vertebral injuries, such as bone fractures (10.3–48%), traumas of the thoracic cavity and its internal organs (as high as 52%), and lumbar spine injuries – with broken limb bones (up to 27%) and pelvic bones (up to 15%), and damage of the abdominal organs (9.8–18.7%) [21, 27–31]. By type, SCIs are divided into open (penetrating) and closed (nonpenetrating) injuries to the spine. In peacetime, closed SCI account for 70.1–88.6% of cases [26, 32].
