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Study documents safety, improvements from stem cell therapy after spinal cord injury
A Mayo Clinic study shows stem cells derived from patients' own fat are safe and may improve sensation and movement after traumatic spinal cord injuries. The findings from the Phase I clinical trial appear in Nature Communications. The results of this early research offer insights into the potential of cell therapy for people living with spinal cord injuries and paralysis for whom options to improve function are extremely limited.
In the study of 10 adults, the research team noted seven participants demonstrated improvements based on the American Spinal Injury Association (ASIA) Impairment Scale. Improvements included increased sensation when tested with pinprick and light touch, increased strength in muscle motor groups, and recovery of voluntary anal contraction, which aids in bowel function.
The scale has five levels, ranging from complete loss of function to normal function. The seven participants who improved each moved up at least one level on the ASIA scale. Three patients in the study had no response, meaning they did not improve but did not get worse.
"This study documents the safety and potential benefit of stem cells and regenerative medicine," says Mohamad Bydon, M.D., a Mayo Clinic neurosurgeon and first author of the study.
"Spinal cord injury is a complex condition. Future research may show whether stem cells in combination with other therapies could be part of a new paradigm of treatment to improve outcomes for patients."
No serious adverse events were reported after stem cell treatment. The most commonly reported side effects were headache and musculoskeletal pain that resolved with over-the-counter treatment.
In addition to evaluating safety, this Phase I clinical trial had a secondary outcome of assessing changes in motor and sensory function. The authors note that motor and sensory results are to be interpreted with caution given limits of Phase I trials. Additional research is underway among a larger group of participants to further assess risks and benefits.
The full data on the 10 patients follows a 2019 case report that highlighted the experience of the first study participant who demonstrated significant improvement in motor and sensory function.
Stem cells' mechanism of action not fully understood
In the multidisciplinary clinical trial, participants had spinal cord injuries from motor vehicle accidents, falls and other causes. Six had neck injuries; four had back injuries. Participants ranged in age from 18 to 65.
Participants' stem cells were collected by taking a small amount of fat from a 1- to 2-inch incision in the abdomen or thigh. Over four weeks, the cells were expanded in the laboratory to 100 million cells and then injected into the patients' lumbar spine in the lower back. Over two years, each study participant was evaluated at Mayo Clinic 10 times.
Although it is understood that stem cells move toward areas of inflammation—in this case the location of the spinal cord injury—the cells' mechanism of interacting with the spinal cord is not fully understood, Dr. Bydon says.
As part of the study, researchers analyzed changes in participants' MRIs and cerebrospinal fluid as well as in responses to pain, pressure and other sensation. The investigators are looking for clues to identify injury processes at a cellular level and avenues for potential regeneration and healing.
The spinal cord has limited ability to repair its cells or make new ones. Patients typically experience most of their recovery in the first six to 12 months after injuries occur. Improvement generally stops 12 to 24 months after injury.
One unexpected outcome of the trial was that two patients with cervical spine injuries of the neck received stem cells 22 months after their injuries and improved one level on the ASIA scale after treatment. Two of three patients with complete injuries of the thoracic spine—meaning they had no feeling or movement below their injury between the base of the neck and mid-back—moved up two ASIA levels after treatment.
Each regained some sensation and some control of movement below the level of injury. Based on researchers' understanding of traumatic thoracic spinal cord injury, only 5% of people with a complete injury would be expected to regain any feeling or movement.
"In spinal cord injury, even a mild improvement can make a significant difference in that patient's quality of life," Dr. Bydon says.
Research continues into stem cells for spinal cord injuries
Stem cells are used mainly in research in the U.S., and fat-derived stem cell treatment for spinal cord injury is considered experimental by the Food and Drug Administration.
Between 250,000 and 500,000 people worldwide suffer a spinal cord injury each year, according to the World Health Organization.
An important next step is assessing the effectiveness of stem cell therapies and subsets of patients who would most benefit, Dr. Bydon says. Research is continuing with a larger, controlled trial that randomly assigns patients to receive either the stem cell treatment or a placebo without stem cells.
"For years, treatment of spinal cord injury has been limited to supportive care, more specifically stabilization surgery and physical therapy," Dr. Bydon says.
"Many historical textbooks state that this condition does not improve. In recent years, we have seen findings from the medical and scientific community that challenge prior assumptions. This research is a step forward toward the ultimate goal of improving treatments for patients."
注释：
Mayo: n
表示"梅奥（爱尔兰西北部一郡）;<非正式> 蛋黄酱（=mayonnaise）"
pinprick: v; v
表示" 针刺"，means "small puncture (as if made by a pin)"，如：The purpose is to observe the effect of LIDP with different pinprick methods, and then we can choose the best way to improve the effect. 目的是观察不同针刺方法治疗腰椎间盘突出症的临床疗效，以选择最佳治疗方法，提高疗效。
paradigm: n
表示" 范例；示范"，means "a standard or typical example"，如：There's no paradigm to follow in this new industry. 在这个崭新的行业里没有范例可做参考。
musculoskeletal: adj
表示"[解]肌(与)骨骼的"，means "relating to muscles and skeleton"，如：The musculoskeletal system is also a finite element model, and FE analysis can be performed for global or local skeletal components. 它同时是人体全身骨肌系统的有限元模型，可以做全身骨骼或局部骨骼的有限元分析。
cerebrospinal: adj
表示"脑脊髓的"，means "of or relating to the brain and spinal cord"，如：cerebrospinal fluid 脑脊髓液
thoracic: adj
表示" 胸的；胸廓的"，means "of or relating to the chest or thorax"，如：The abdominal aorta is normally smaller than the thoracic aorta. 腹主动脉一般比胸主动脉小。
subsets: n
表示"特征子集"，means "a set whose members are members of another set; a set contained within another set"，如：Subsets of these can be rerun as necessary. 这些测试的子集合可以在需要的时候重新运行。
中文简要说明：
脊髓是人体的神经主干道，一旦损伤就会造成瘫痪。据世界卫生组织称，全世界每年有 25 万至50万人遭受脊髓损伤，因此再生医学界一直在想办法克服这个难题。被誉为「万能细胞」的干细胞是最可能修复脊髓损伤的材料，现在美国一间著名的医院，在初期的干细胞实验疗法中，也获得令人可喜的进展，10名患者有7成出现功能改善，即使没有改善，至少也没有恶化。
医疗讯息(MedicalxPress)报导，美国著名的妙佑医疗集团 (Mayo Clinic )，对脊损患者进行自体干细胞治疗，是利用患者自身脂肪干细胞，已确定这是安全的，并且可以改善脊髓伤害后的感觉和运动。改进的部分包括针刺和轻触测试时，患者的感觉有所增强，肌肉运动群的力量增强，以及肠道功能，尤其是自主肛门收缩都有恢复。
研究团队利用美国脊椎损伤协会 (ASIA) 损伤量表，来判断10名患者的治疗后表现，有 7 名参与者表现出改善，虽然3名患者没有任何反应，但至少他们没有恶化。
治疗仅出现小程度的副作用，最常见的副作用是头痛和肌肉骨骼疼痛，这部分可以透过非处方治疗解决。
在这项多学科的临床试验中，参与者的脊损原因各有不同，包括车祸、跌伤和其他原因，其中6人伤于颈部；4人伤于背部。参与者的年龄从 18 岁到 65 岁不等。
参与者的干细胞，是从腹部或大腿，以1至2 寸的切口，收集到少量的脂肪干细胞。在随后的四个星期，这些干细胞在实验室里培养，扩增到1亿个，然后注射到患者下背部的腰椎。经过两年多的治疗，每位参与者接受了 10 次评估。
论文第一作文拜登博士(Mohamad Bydon)说：「我们知道干细胞会向发炎区域移动，在本例中是脊髓损伤的位置，但细胞与脊髓相互作用的机制，目前尚不完全清楚，不过它们确实表现出修复的功能。」
脊髓损伤后，制造新细胞的能力非常有限，患者通常在受伤后的前 6 至 12 个月内会有一定程度的改善，但是在受伤后的12至 24 个月，改善通常会停止。
而这一次实验，出现了意想不到的结果，两名颈椎损伤的患者，在受伤后 22 个月接受了干细胞治疗，结果ASIA 量表提高了一级。3名胸椎完全损伤的患者中的两名，治疗后ASIA上升了2个等级；也就是说，每个人都恢复了一些感觉，以及受伤位置以下的一些控制能力，这是非常好的现象。
拜登博士说，下一步要评估干细胞疗法的有效性，以及最能受益的患者类群。
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