Immune depression syndrome following human spinal cord injury (SCI): a pilot study

Experimental spinal cord injury (SCI) has been identified to trigger a systemic, neurogenic immune depression syndrome. Here, we have analyzed fluctuations of immune cell populations following human SCI by FACS analysis. In humans, a rapid and drastic decrease of CD14+ monocytes (<50% of control level), CD3+ T-lymphocytes (<20%, P<0.0001) and CD19+ B-lymphocytes (<30%, P=0.0009) and MHC class II (HLA-DR)+ cells (<30%, P<0.0001) is evident within 24 h after spinal cord injury reaching minimum levels within the first week. CD15+ granulocytes were the only leukocyte subpopulation not decreasing after SCI. A contributing, worsening effect of high dose methylprednisolone cannot be excluded with this pilot study. We demonstrate that spinal cord injury is associated with an early onset of immune suppression and secondary immune deficiency syndrome (SCI-IDS). Identification of patients suffering spinal cord injury as immune compromised is a clinically relevant, yet widely underappreciated finding.