Introduction
Spinal cord injury (SCI) is one of the worst kinds of traumatic injuries with great social and economic impacts on communities. An estimated 5.2 million people are living with spinal cord injuries with incidence of 130,000 new cases per year all over the world (1). The estimated annual cost of care for patients with SCI in the United States is 73.9 billion (2).
During the acute phase of SCI, the focal mechanical impact triggers a cascade of destructive processes in which multiple secondary damages such as necrosis and apoptotic death of neurons and irreversible axonal damage and demyelization play role (3,4). Spinal cord injury causes rapid loss of axons that occurs within a week of the injury. Although most of this loss occurs during the first week but axons remodeling, tissue remodeling, and pathology can be detected up to 10 weeks after injury (5). 
Effective treatment for spinal cord injuries is limited by complex pathophysiology of causative mechanisms (6). There are limited medical therapies for spinal cord injury. According to a study of the national acute spinal cord injury study 2 (NASCIS-2), the use of high-dose methylprednisolone has been confirmed as the standard treatment for spinal cord injuries. Studies have shown that methylphenidate prednisolone used within eight hours of injury have improved sensory and motor outcomes (7, 8). However, several studies have shown that after this treatment, side effects, respiratory system and digestive organs damage occurred frequently and were often serious (9-14).
Granulocyte colony-stimulating factor (GCS-F) is a glycoprotein which is proposed to have anti-inflammatory effects (15). Numerous reports show that G-CSF has anti-inflammatory effects and inhibits apoptotic pathways (16-21). G-CSF receptors are expressed in neural stem cells and cause neuronal differentiation in vitro. It protects neural tissue from glutamate-induced neurotoxicity during spinal cord injury process (22) .
Based on these results, we performed a clinical trial and compared the safety and feasibility of G-CSF and high-dose methylprednisolone as neuroprotective therapy in patients with acute SCI.

Methods and Materials/Patients 
The study was designed as a prospective randomized clinical trial to compare G-CSF and high-dose methylprednisolone as neuroprotective therapy in patients with acute traumatic spinal cord injury.
122 patients with traumatic spinal cord injury were admitted to Poursina hospital within 48 hours of injury. They were enrolled into the study according to the following inclusion criteria:
- Acute (up to 48 hours) traumatic spinal cord injury 
- Age between 18 to 65 years old
- Absence of intracranial lesion such as a tumor, infection, ischemia or trauma.
- No past history of major bleeding requiring blood transfusion
- No past history of leukopenia or thrombocytopenia
- No past history of hepatic or renal dysfunction
- No past history of severe heart failure
- Absence of splenomegaly or a related history 
- No evidence of malignant disease in the past five years
- No pregnancy or lactation in patients
Patients with history of major bleeding, blood dyscrasia, renal and hepatic failure and history of malignant disease in the past five years were excluded. Written informed consent was obtained from all patients prior to the treatment in both groups.
The baseline grade of spinal cord injury using AIS scoring system and sensory and motor function score of patients were measured using the ASIA scoring system. 
The patients were randomized into two groups. In the first group, treatment with bolus dose of 15 mg/kg of methylprednisolone sodium succinate during the first eight hours after injury was begun. If the treatment was started within three hours after injury, methylprednisolone infusion continued with a dose of 5.4 mg/kg/h to 23 hours later on. If the treatment was started within three to eight hours of injury onset, infusion of methylprednisolone continued up to 47 hours later on with same dosages.
In the second group, treatment with G-CSF was administered at a dose of 10 micrograms/kg daily for five consecutive days. Vital signs, clinical condition and blood profile were assessed for seven days according to the manufacturer's protocol. The patients were checked for possible side effects. In case of pain or fever over 38 °C the patients were given nonsteroidal anti-inflammatory drugs such as diclofenac. Treatment was ended in the case of severe side effects.
In both groups of patients, recovery of sensory and motor function was assessed by ASIA scoring system and AIS grading system one week, three months and six months after the intervention consecutively. 

Results
In current research, 122 patients were studied. Out of 62 patients in the G-CSF group with a mean age of 40.4 (SD=16.02), 47 patients (75.8%) were male and 15 (24.2%) female. The methylprednisolone group also included 60 patients with an average age of 40.10 years (SD=13.22), in which 48 patients (80%) were male and 12 (20%) female.
55 (45%) out of 122 patients were completely paralyzed (Grade AIS: A) and 67 (55%) were with incomplete spinal injury (Grade AIS: B, C, D).
The most common cause of trauma was motor car accident with 71 cases (58.2%) followed by falls with 43 cases (35.2%), 
conflicts with 5 cases (4.1%) and sports injury with 3 cases (2.5%). Based on the level of damage, most of them were cervical injuries with 80 cases (65.6%).
The average ASIA motor scores in the two groups in sequential intervals of first day, seventh day, three and six months later were compared in two groups. The p-values were 0.7, 0.4, 0.1 and 0.05, respectively. The average ASIA sensory scores in the two groups were similarly compared in the same time intervals and p values were 0.7, 0.3, 0.2, and 0.1, respectively. They were not shown to be statistically significant. Only the comparison between average ASIA motor and sensory scores in the two groups of male patients sub-group differed significantly within six months of onset of G-CSF treatment (p-value=0.04). The average ASIA motor scores improvement in the falls sub-group patients also differed significantly within six months of onset of G-CSF treatment (p-value=0.03).
The difference observed in the prevalence of AIS grades at the time of acute traumatic SCI examined in patients treated with G-CSF compared to those treated with methylprednisolone was not statistically significant in any of the mentioned time intervals (p>0.05). 

Conclusion
122 patients with traumatic SCI admitted to Poursina hospital within 48 hours of injury were assessed by prospective randomized clinical trial comparing G-CSF and high-dose methylprednisolone as neuroprotective therapy. According to the results, there was no significant difference between two groups in terms of age, sex and cause of trauma.
In the present study, neurological improvement between the two groups of G-CSF and high-dose methylprednisolone based on average ASIA motor and sensory scores and AIS grading scales in the two groups in sequential intervals of the first day and seventh day, three and six months after the intervention were compared. There was a significant difference between the two groups in the average ASIA motor and sensory scores after six months of injury in male patients (p-value=0.04), as well as in patients injured by falls (p-value=0.03). However, overall improvement of ASIA motor, sensory scores and AIS grading scales did not differ significantly (p-value>0.05).
In review of similar articles, Takahashi and colleagues in 2012 compared two different G-CSF treatment's protocols with five and 10 micrograms/kg/day of IV infusion for five days consequently in patients at first 24 hours of acute spinal injuries to show efficacy and safety of G-CSF treatment. It showed progression in neurological outcomes, but the samples were few to be fully comprehended. It also only analyzed the partial spinal cord injured patients (23).
Saberi and colleagues in 2012 compared two partial and complete chronic spinal injury groups of patients treated by five micrograms/kg/day subcutaneous injection for seven days consecutively. Patients with incomplete SCI had greater improvement in motor and grading ASIA scores compared to complete SCI patients. The higher grades of injuries were correlated with poorer results. The article only assessed the chronic phase of injury and did not compare it with other treatment modalities (24).
In a retrospective study conducted by Kamiya and colleagues in 2015, two groups of nonrandomized partial SCI treated by G-CSF and high-dose methylprednisolone followed up to three months were compared. It showed superior improvement in motor and grading ASIA score in G-CSF group. It lacked long-term follow-up in non-randomized trial and also did not include complete SCI patients in the assessment (25). 
Inada and colleagues in 2014 also compared patients with
traumatic spinal cord injury admitted within 48 hours of injury treated by G-CSF and compared it with control group without medical neuroprotective treatment in non-randomized prospective trial and followed patients for one year later on, in seven days, three months, six months and one year after injury. It showed improvement in motor and grading ASIA score in G-CSF treated ones compared to control group at first week and a year later, though it lacked randomization and the G-CSF intervention was not compared to other modalities (26).
In our study, the sampling was greater in number than that in all other similar articles, and it is the only prospective randomized clinical trial that compared G-CSF and high-dose methylprednisolone as neuroprotective therapy in patients with acute traumatic spinal cord injury. Moreover, it compared all complete and partial SCI cases (grades A, B, C and D).

Recommendation
We recommend the multicenter prospective randomized clinical trial to compare the placebo effect with that of G-CSF protocol's treatment, and also assessment of the cost benefits of the common medical treatment with those of G-CSF.

Funding
None.

Conflicts of Interest
The authors have no conflicts of interest.


References