Subacute human spinal cord contusion: few lymphocytes and many macrophages

Abstract

Study design: Clinicopathological correlation of three cases of subacute cervical spinal cord contusions. Objective: To correlate the pathology of subacute cervical spinal cord injury (SCI) with imaging and clinical-functional studies, and to compare with findings from previous human SCI studies and animal models of SCI. Setting: Department of Pathology, SUNY-Upstate Medical University, Syracuse, NY, USA. Method: Post mortem pathology report. Case report/Results: The clinical, radiological, and pathological findings of three cases of subacute spinal cord contusions are described in detail. The postinjury survival periods were 15, 20, and 60 days, respectively. Extensive microglia/macrophage infiltrations without significant lymphocytes are seen in all cases. Free radical injury as assessed by immunocytochemistry for 4-hydroxynonenal and nitrotyrosine showed a labeling pattern parallel to that of the macrophage distribution at 15 days, but no significant labeling in the injury sites at 20 and 60 days. Conclusion: The present report, though limited in sample size, shows plenty of activated microglia/macrophages in human SCI up to 60 days postinjury. This observation not only confirms similar findings in previous studies, but also raises an intriguing question of potential interactions between these activated microglia/macrophages and the experimental therapy, proposed by some authors, of injecting exogenously activated macrophages to promote SCI repair. The small number of human SCI cases (in this as well as in most other single medical centers) available for detailed study illustrates the need for the establishment of a consortium of human SCI tissue banks.

Kallikrein Cascades in Traumatic Spinal Cord Injury: In Vitro Evidence for Roles in Axonopathy and Neuron Degeneration

“…The inflammatory response in spinal cord trauma is complex and includes both cellular and chemical mediators (67, 69, 87–90). Corresponding to what has been reported, monocytes and microglia reactive for the lysosomal marker CD68 were observed from acute through the most chronic time points of human SCI examined and were most abundant from the subacute period onward (43, 69).…”

Modulation of Thalamic Nociceptive Processing after Spinal Cord Injury through Remote Activation of Thalamic Microglia by Cysteine–Cysteine Chemokine Ligand 21

“…Microglia also become activated in the spinal cord after clinical (Chang, 2007) and experimental spinal cord injury (SCI) (Popovich et al, 1997;Hains et al, 2003;Sroga et al, 2003;Nesic et al, 2005;Zai and Wrathall, 2005;Crown et al, 2006;Zhao et al, 2007). The identification of unique, injury-induced regional stimulators of microglia will be critical to our understanding, as well as management, of signaling pathways underlying chronic pain after SCI.…”

Spinal cord injury – scientific challenges for the unknown future

“…All tissues harbour mononuclear cells, which together form the mononuclear phagocyte system, and have the ability to rapidly transform into macrophages in trauma and disease. Macrophages have long been known to play a key role in inflammation, including the repair of injured peripheral nerves (39). Recent studies indicate that an inadequate macrophage response in the injured central nervous system is an important factor behind the failure of axon regeneration in the spinal cord.…”